WO2023071866A1 - 指示信息的传输方法、消息传输方法及相关装置 - Google Patents

指示信息的传输方法、消息传输方法及相关装置 Download PDF

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Publication number
WO2023071866A1
WO2023071866A1 PCT/CN2022/125902 CN2022125902W WO2023071866A1 WO 2023071866 A1 WO2023071866 A1 WO 2023071866A1 CN 2022125902 W CN2022125902 W CN 2022125902W WO 2023071866 A1 WO2023071866 A1 WO 2023071866A1
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network element
user plane
plane network
data packet
target
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PCT/CN2022/125902
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English (en)
French (fr)
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戚彩霞
朱奋勤
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华为技术有限公司
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Publication of WO2023071866A1 publication Critical patent/WO2023071866A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W28/00—Network traffic management; Network resource management
    • H04W28/02—Traffic management, e.g. flow control or congestion control
    • H04W28/10—Flow control between communication endpoints
    • H04W28/14—Flow control between communication endpoints using intermediate storage
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W36/00—Hand-off or reselection arrangements
    • H04W36/02—Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W40/00—Communication routing or communication path finding
    • H04W40/02—Communication route or path selection, e.g. power-based or shortest path routing
    • H04W40/20—Communication route or path selection, e.g. power-based or shortest path routing based on geographic position or location

Definitions

  • the present application relates to the field of communication technologies, and in particular, to a method for transmitting indication information, a method for transmitting messages, and related devices.
  • the data flow of the terminal equipment in the fifth generation mobile communication technology (5th generation mobile networks, 5G) network can be divided through the uplink classifier (uplink classifier, UL CL) or branching point (branching point, BP), so that part of the data flow from The local session anchor point close to the terminal device access location is forwarded, and other data streams are forwarded from the remote session anchor point far from the terminal device access location, so that when the application server is deployed at a low location, the data packet forwarding path can be shortened. Reduce latency.
  • uplink classifier uplink classifier, UL CL
  • branching point branching point
  • the terminal device When the terminal device moves, it may cause the uplink splitter and the local session anchor to change simultaneously, or the split point and the local session anchor to change simultaneously. In this case, there may be packet loss. Therefore, how to avoid data packet loss and improve the reliability of data packet transmission has become an urgent problem to be solved.
  • the present application provides a method for transmitting indication information, a method for message transmission and related devices, which can avoid the loss of data packets and improve the reliability of data packet transmission.
  • a method for transmitting indication information comprising: an intermediate session management network element sends first indication information to the session management network element, and the first indication information is used to indicate that the intermediate session management network element has inserted the target offloading user The user plane NE and the target user plane NE, as well as the source offload user plane NE and the source user plane NE have been deleted.
  • the intermediate session management network element receives second indication information from the session management network element, where the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the intermediate session management network element sends third indication information to the target user plane network element according to the second indication information, where the third indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the intermediate session management network element receives fourth indication information from the session management network element, where the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the intermediate session management network element sends fifth indication information to the target user plane network element according to the fourth indication information, where the fifth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the intermediate session management network element may send the first indication information to the session management network element, so that the session management network element may know that the intermediate session management network element has been inserted into the target offloading user plane network element and the target user plane network element, And the source offload user plane network element and the source user plane network element have been deleted, so that the intermediate session management network element can send the third indication information to the target user plane network element according to the second indication information from the session management network element, so that the target The user plane network element buffers the uplink data packet according to the third indication information.
  • the session management network element when the session management network element knows that the target application network element has completed the handover, it can send the fourth indication information to the intermediate session management network element, so that the intermediate session management network element sends the fifth indication information to the target user plane network element according to the fourth indication information. indication information, and then let the target user plane network element forward the uplink data packet according to the fifth indication information. Understandably, since the target user plane network element does not forward the uplink data packet before the target application network element completes the handover, but buffers the uplink data packet before the target application network element completes the handover, the uplink data packet is not forwarded, avoiding Uplink packet loss. In addition, since the target user plane network element forwards the uplink data packet after the target application network element completes the handover, the uplink data packet can be forwarded to the target application network element, which improves the reliability of data packet transmission.
  • the method further includes: the intermediate session management network element sends a first packet forwarding control protocol request message to the user plane network element, and the first packet forwarding control protocol request message includes a first packet detection rule (packet detection rule) rule, PDR) and the first packet forwarding rule (forwarding action rule, FAR).
  • the first packet forwarding control protocol request message includes a first packet detection rule (packet detection rule) rule, PDR) and the first packet forwarding rule (forwarding action rule, FAR).
  • the first data packet detection rule is a rule corresponding to a source offload user plane network element detecting a data packet from a target offload user plane network element
  • the first data packet forwarding rule is The source offload user plane network element forwards the rules corresponding to the data packets from the target offload user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the target access network device
  • the first data packet forwarding rule is the target The offload user plane network element forwards the rule corresponding to the data packet from the target access network device to the source offload user plane network element.
  • the intermediate session management network element may send a first data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the first data packet forwarding control protocol request message includes the first data packet detection rule and The first data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the first data packet detection rule, and forwards the data packet according to the first data packet forwarding rule, so that the target application network element Before the handover is completed, the uplink data packet is sent from the source user plane network element to the source application network element, which avoids the loss and interruption of the uplink data packet of the terminal device, and improves the continuity and reliability of data packet transmission.
  • the method further includes: the intermediate session management network element receiving the second data packet detection rule, the second data packet forwarding rule and sixth indication information from the session management network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the intermediate session management network element can receive the second data packet detection rule, the second data packet forwarding rule and the sixth indication information from the session management network element, so that the intermediate session management network element can learn one or more of the following Item:
  • the second data packet detection rule is the rule corresponding to the source offload user plane NE or the target offload user plane NE detection packet, and the second data packet forwarding rule is forwarded by the source offload user plane NE or the target offload user plane NE
  • the rules corresponding to the packets is the rules corresponding to the packets.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained.
  • the first data packet detection rule is that the intermediate session management network element adds the source offload user plane network element’s tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier of the source user plane network element and the source user to the second data packet forwarding rule according to the sixth instruction information. Obtain the IP address of the plane network element.
  • the first packet forwarding rule also includes The tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE enable the target offload user plane NE to The protocol address receives and detects the data packet, and establishes a tunnel according to the tunnel endpoint identifier of the source offload user plane NE, the IP address of the source offload user plane NE, and the source offload user plane NE, so that the data packet can be transmitted through the tunnel, avoiding The loss and interruption of the uplink data packets of the terminal equipment are eliminated.
  • the first data packet forwarding rule also includes the source user plane network element's The tunnel endpoint identifier and the IP address of the source user plane network element enable the source offload user plane network element to receive and detect the data packet according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, According to the tunnel endpoint identifier of the source user plane network element and the IP address of the source user plane network element, a tunnel is established with the source user plane network element, so that the data packets can be transmitted through the tunnel, avoiding the loss and interruption of the uplink data packets of the terminal equipment .
  • a message transmission method includes: an intermediate session management network element sends a third data packet forwarding control protocol request message to a user plane network element, and the third data packet forwarding control protocol request message includes a third data packet A detection rule and a third packet forwarding rule.
  • the third data packet detection rule is a rule corresponding to the source offload user plane network element detecting a data packet from a remote user plane network element
  • the third data packet forwarding rule is The source offload user plane network element forwards a rule corresponding to the data packet from the remote user plane network element to the target offload user plane network element; or, the third data packet detection rule is that the source offload user plane network element detects the packet from the source user plane network element
  • the third data packet forwarding rule is a rule corresponding to forwarding the data packet from the source user plane network element to the target offload user plane network element by the source offload user plane network element.
  • the third data packet detection rule is a rule corresponding to the target offload user plane network element detecting a data packet from the source offload user plane network element
  • the third data packet forwarding rule is The target offload user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the intermediate session management network element may send a third data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the third data packet forwarding control protocol request message includes the third data packet detection rule and the third data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the third data packet detection rule, and forwards the data packet according to the third data packet forwarding rule, avoiding the terminal device
  • the loss and interruption of downlink data packets improves the continuity and reliability of data packet transmission.
  • the method further includes: the intermediate session management network element receiving the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information from the session management network element.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the intermediate session management network element can receive the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information from the session management network element, so that the intermediate session management network element can know the following One or more items: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet, the fourth data packet forwarding rule is the source offload user plane network element or the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the third data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information
  • the identity and IP address of the target access network device are obtained.
  • the third data packet detection rule is that the intermediate session management network element adds the source offload user plane network element's tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and target address of the target offloading user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the IP address of the offload user plane network element is obtained.
  • the third data packet forwarding rule also includes the target access network device The tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that the target offload user plane network element can receive and detect the data packet according to the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element , establishing a tunnel with the target access network device according to the tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that data packets can be transmitted through the tunnel, and the loss of downlink data packets of the terminal device is avoided.
  • the third data packet forwarding rule also includes the target offload user plane network element The tunnel endpoint identifier of the source offload user plane network element and the IP address of the target offload user plane network element, so that the source offload user plane network element can receive and detect data according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element packet, according to the tunnel endpoint identifier of the target offload user plane NE, the IP address of the target offload user plane NE, and the target offload user plane NE to establish a tunnel, so that the data packet can be transmitted through the tunnel, avoiding the downlink data of the terminal equipment Packet loss.
  • a method for transmitting indication information comprising: a session management network element receives first indication information from an intermediate session management network element, and the first indication information is used to indicate that the intermediate session management network element has inserted a target offloading user The user plane NE and the target user plane NE, as well as the source offload user plane NE and the source user plane NE have been deleted.
  • the session management network element sends second indication information to the intermediate session management network element according to the first indication information, and the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the session management network element sends fourth indication information to the intermediate session management network element, the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet, and the fourth indication information is that the session management network element learns that the target application network element has completed the handover Instructions sent later.
  • the session management network element may receive the first indication information from the intermediate session management network element, so that the session management network element may know that the intermediate session management network element has been inserted into the target offloading user plane network element and the target user plane network element, And the source offload user plane network element and the source user plane network element have been deleted, and the second indication information is sent to the intermediate session management network element according to the first indication information, so that the target user plane network element is cached before the target application network element completes the handover Uplink data packets, so that the uplink data packets are not forwarded, avoiding the loss of the uplink data packets.
  • the session management network element sends the fourth instruction information to the intermediate session management network element, so that the target user plane network element forwards the uplink data packet after the target application network element completes the handover, so that the uplink data packet can be forwarded to the target application network element , improving the reliability of data packet transmission.
  • the method further includes: the session management network element sending the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the session management network element can send the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element, so that the intermediate session management network element can learn one or more of the following: the second data packet
  • the packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element to detect the data packet
  • the second data packet forwarding rule is the corresponding rule to the source offload user plane network element or the target offload user plane network element to forward the data packet .
  • a method for transmitting indication information comprising: a user plane network element receives third indication information from an intermediate session management network element, and the third indication information is used to instruct the user plane network element to cache uplink data packets.
  • the user plane network element receives fifth indication information from the intermediate session management network element, where the fifth indication information is used to instruct the user plane network element to forward the uplink data packet.
  • the user plane network element can receive the third indication information for instructing the user plane network element to buffer the uplink data packet from the intermediate session management network element, so that the target user plane network element can complete the handover before the target application network element Uplink data packets are cached so that the uplink data packets are not forwarded, thereby avoiding loss of uplink data packets.
  • the user plane network element can receive the fifth instruction information for instructing the user plane network element to forward the uplink data packet from the intermediate session management network element, so that the target user plane network element forwards the uplink data after the target application network element completes the handover packet, so that the uplink data packet can be forwarded to the target application network element, which improves the reliability of data packet transmission.
  • the method further includes: the user plane network element receives a first data packet forwarding control protocol request message from an intermediate session management network element, and the first data packet forwarding control protocol request message includes the first data packet detection rule and the first Packet forwarding rules.
  • the first data packet detection rule is a rule corresponding to a source offload user plane network element detecting a data packet from a target offload user plane network element
  • the first data packet forwarding rule is The source offload user plane network element forwards the rules corresponding to the data packets from the target offload user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the target access network device
  • the first data packet forwarding rule is the target The offload user plane network element forwards the rule corresponding to the data packet from the target access network device to the source offload user plane network element.
  • the source offload user plane network element or the target offload user plane network element can receive the first packet forwarding control protocol request message from the intermediate session management network element, and the first packet forwarding control protocol request message includes the first packet detection rule and The first data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the first data packet detection rule, and forwards the data packet according to the first data packet forwarding rule, so that the target application network element Before the handover is completed, the uplink data packet is sent from the source user plane network element to the source application network element, which avoids the loss and interruption of the uplink data packet of the terminal device, and improves the continuity and reliability of data packet transmission.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained.
  • the first data packet detection rule is that the intermediate session management network element adds the source offload user plane network element’s tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier of the source user plane network element and the source user to the second data packet forwarding rule according to the sixth instruction information. Obtain the IP address of the plane network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the first packet forwarding rule also includes the source offload user plane network The tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, so that the target offload user plane network element can receive and detect according to the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element
  • a tunnel is established according to the tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE and the source offload user plane NE, so that the data packet can be transmitted through the tunnel, avoiding the uplink of the terminal equipment Packet loss.
  • the first data packet forwarding rule also includes the source user plane network element's The tunnel endpoint identifier and the IP address of the source user plane network element enable the source offload user plane network element to receive and detect the data packet according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, According to the tunnel endpoint identifier of the source user plane network element and the IP address of the source user plane network element, a tunnel is established with the source user plane network element, so that the data packets can be transmitted through the tunnel, and the loss of the uplink data packets of the terminal equipment is avoided.
  • a message transmission method comprising: a user plane network element receives a third data packet forwarding control protocol request message from an intermediate session management network element, and the third data packet forwarding control protocol request message includes a third data packet A detection rule and a third packet forwarding rule.
  • the third data packet detection rule is the rule corresponding to the source offload user plane network element detecting a data packet from a remote user plane network element, and the third data packet forwarding rule is source offload The user plane network element forwards the corresponding rule for the data packet from the remote user plane network element to the target offload user plane network element; or, the third data packet detection rule is that the source offload user plane network element detects the data from the source user plane network element.
  • the rule corresponding to the packet, the third data packet forwarding rule is a rule corresponding to forwarding the data packet from the source user plane network element to the target offload user plane network element by the source offload user plane network element.
  • the third data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the source offload user plane network element
  • the third data packet forwarding rule is the target offload The user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the source offload user plane network element or the target offload user plane network element can receive the third data packet forwarding control protocol request message from the intermediate session management network element, and the third data packet forwarding control protocol request message includes the third data packet detection rule and
  • the third data packet forwarding rule makes the source offload user plane network element or the target offload user plane network element detect the data packet according to the third data packet detection rule, and forward the data packet according to the third data packet forwarding rule, avoiding the downlink of the terminal equipment
  • the loss of data packets improves the reliability of data packet transmission.
  • the third data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information
  • the identity and IP address of the target access network device are obtained.
  • the third data packet detection rule is that the intermediate session management network element adds the source offload user plane network element's tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and target address of the target offloading user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the IP address of the offload user plane network element is obtained.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the third data packet forwarding rule also includes the target access network device
  • the tunnel endpoint identifier and the IP address of the target access network device enable the target offload user plane network element to receive and detect the data packet according to the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element, A tunnel is established with the target access network device according to the tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that data packets can be transmitted through the tunnel, and the loss of downlink data packets of the terminal device is avoided.
  • the third data packet forwarding rule also includes the target The tunnel endpoint identifier of the offload user plane NE and the IP address of the target offload user plane NE, so that the source offload user plane NE can use the tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE
  • the address receives and detects the data packet, and establishes a tunnel according to the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element and the target offload user plane network element, so that the data packet can be transmitted through the tunnel, avoiding the The loss of downlink data packets of the terminal equipment.
  • a method for transmitting indication information comprising: the intermediate session management network element sends first indication information to the session management network element, and the first indication information is used to indicate that the intermediate session management network element has inserted the target offloading user The user plane NE and the target user plane NE, as well as the source offload user plane NE and the source user plane NE have been deleted.
  • the session management network element sends second indication information to the intermediate session management network element according to the first indication information, and the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the target user plane network element receives third indication information from the intermediate session management network element, the third indication information is sent by the intermediate session management network element according to the second indication information, and the third indication information is used to instruct the target user plane network element to cache the uplink data packet .
  • the session management network element sends fourth indication information to the intermediate session management network element, the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet, and the fourth indication information is that the session management network element learns that the target application network element has completed the handover Instructions sent later.
  • the intermediate session management network element sends fifth indication information to the target user plane network element according to the fourth indication information, where the fifth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the target user plane network element since the target user plane network element does not forward the uplink data packet before the target application network element completes the handover, but buffers the uplink data packet before the target application network element completes the handover, the uplink data packet is not forwarded Forwarding, avoiding the loss of uplink data packets.
  • the target user plane network element since the target user plane network element forwards the uplink data packet after the target application network element completes the handover, the uplink data packet can be forwarded to the target application network element, which improves the reliability of data packet transmission.
  • the method further includes: the intermediate session management network element sends a first data packet forwarding control protocol request message to the user plane network element, and the first data packet forwarding control protocol request message includes the first data packet detection rule and the first Packet forwarding rules.
  • the first data packet detection rule is the rule corresponding to the source offload user plane network element detecting data packets from the target offload user plane network element
  • the first data packet forwarding rule is source offload The user plane network element forwards the rules corresponding to the data packets from the target offloading user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the detection of data packets from the target access network device by the target offload user plane network element
  • the first data packet forwarding rule is the target offload user plane rule.
  • the intermediate session management network element may send the first data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the first data packet forwarding control protocol request message Including the first data packet detection rule and the first data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the first data packet detection rule, and forwards the data according to the first data packet forwarding rule packet, which avoids the loss of the uplink data packet of the terminal equipment and improves the reliability of data packet transmission.
  • the method further includes: the session management network element sends the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the session management network element can send the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element, so that the intermediate session management network element can know the following: One or more items: the second data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet, and the second data packet forwarding rule is the source offload user plane network element or the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained.
  • the first data packet detection rule is that the intermediate session management network element adds the source offload user plane network element’s tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier of the source user plane network element and the source user to the second data packet forwarding rule according to the sixth instruction information. Obtain the IP address of the plane network element.
  • the first packet forwarding rule since the first packet detection rule also includes the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element, the first packet forwarding rule also includes The tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE enable the target offload user plane NE to The protocol address receives and detects the data packet, and establishes a tunnel according to the tunnel endpoint identifier of the source offload user plane NE, the IP address of the source offload user plane NE, and the source offload user plane NE, so that the data packet can be transmitted through the tunnel, avoiding The loss of downlink data packets of the terminal equipment.
  • the first data packet forwarding rule also includes the source user plane network element's The tunnel endpoint identifier and the IP address of the source user plane network element enable the source offload user plane network element to receive and detect the data packet according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, A tunnel is established with the source user plane network element according to the tunnel endpoint identifier of the source user plane network element and the IP address of the source user plane network element, so that data packets can be transmitted through the tunnel, and the loss of downlink data packets of the terminal equipment is avoided.
  • a message transmission method comprising: an intermediate session management network element sends a third data packet forwarding control protocol request message to a user plane network element, and the third data packet forwarding control protocol request message includes a third data packet A detection rule and a third packet forwarding rule.
  • the third data packet detection rule is the rule corresponding to the source offload user plane network element detecting a data packet from a remote user plane network element, and the third data packet forwarding rule is source offload The user plane network element forwards the corresponding rule for the data packet from the remote user plane network element to the target offload user plane network element; or, the third data packet detection rule is that the source offload user plane network element detects the data from the source user plane network element.
  • the rule corresponding to the packet, the third data packet forwarding rule is a rule corresponding to forwarding the data packet from the source user plane network element to the target offload user plane network element by the source offload user plane network element.
  • the third data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the source offload user plane network element
  • the third data packet forwarding rule is the target offload The user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the intermediate session management network element may send a third data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the third data packet forwarding control protocol request message Including a third data packet detection rule and a third data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the third data packet detection rule, and forwards the data according to the third data packet forwarding rule packet, which avoids the loss of downlink data packets of the terminal equipment and improves the reliability of data packet transmission.
  • the method further includes: the session management network element sending the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information to the intermediate session management network element.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the session management network element can send the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information to the intermediate session management network element, so that the intermediate session management network element can know the following One or more items: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet, the fourth data packet forwarding rule is the source offload user plane network element or the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the third data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information
  • the identity and IP address of the target access network device are obtained.
  • the third data packet detection rule is that the intermediate session management network element adds the source offload user plane network element's tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and target address of the target offloading user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the IP address of the offload user plane network element is obtained.
  • the third data packet forwarding rule also includes The tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that the target offload user plane network element can use the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element Receive and detect data packets, establish a tunnel with the target access network device according to the tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that the data packets can be transmitted through the tunnel, avoiding the downlink of the terminal device Packet loss.
  • the third data packet forwarding rule also includes the target offload user plane network element The tunnel endpoint identifier of the source offload user plane network element and the IP address of the target offload user plane network element, so that the source offload user plane network element can receive and detect data according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element packet, according to the tunnel endpoint identifier of the target offload user plane NE, the IP address of the target offload user plane NE, and the target offload user plane NE to establish a tunnel, so that the data packet can be transmitted through the tunnel, avoiding the downlink data of the terminal equipment Packet loss.
  • an intermediate session management network element includes a transceiver module, and the transceiver module is used to send first indication information to the session management network element, and the first indication information is used to indicate the intermediate session management network element
  • the target offload user plane network element and the target user plane network element have been inserted, and the source offload user plane network element and the source user plane network element have been deleted.
  • the transceiver module is configured to receive second indication information from the session management network element, where the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the transceiver module is configured to send third indication information to the target user plane network element according to the second indication information, where the third indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the transceiver module is configured to receive fourth indication information from the session management network element, where the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the transceiver module is configured to send fifth indication information to the target user plane network element according to the fourth indication information, where the fifth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the transceiver module is further configured to send a first packet forwarding control protocol request message to the user plane network element, where the first packet forwarding control protocol request message includes a first packet detection rule and a first packet forwarding rule .
  • the first data packet detection rule is the rule corresponding to the source offload user plane network element detecting data packets from the target offload user plane network element
  • the first data packet forwarding rule is source offload The user plane network element forwards the rules corresponding to the data packets from the target offloading user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the detection of data packets from the target access network device by the target offload user plane network element
  • the first data packet forwarding rule is the target offload user plane rule.
  • the transceiver module is further configured to receive the second data packet detection rule, the second data packet forwarding rule and the sixth indication information from the session management network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained.
  • the first data packet detection rule is that the intermediate session management network element adds the source offload user plane network element’s tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier of the source user plane network element and the source user to the second data packet forwarding rule according to the sixth instruction information. Obtain the IP address of the plane network element.
  • an intermediate session management network element includes a transceiver module, and the transceiver module is used to send a third data packet forwarding control protocol request message to a user plane network element, and the third data packet forwarding control protocol request message
  • the request message includes a third data packet detection rule and a third data packet forwarding rule.
  • the third data packet detection rule is the rule corresponding to the source offload user plane network element detecting a data packet from a remote user plane network element, and the third data packet forwarding rule is source offload The user plane network element forwards the corresponding rule for the data packet from the remote user plane network element to the target offload user plane network element; or, the third data packet detection rule is that the source offload user plane network element detects the data from the source user plane network element.
  • the rule corresponding to the packet, the third data packet forwarding rule is a rule corresponding to forwarding the data packet from the source user plane network element to the target offload user plane network element by the source offload user plane network element.
  • the third data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the source offload user plane network element
  • the third data packet forwarding rule is the target offload The user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the transceiver module is further configured to receive the fourth packet detection rule, the fourth packet forwarding rule, and the seventh indication information from the session management network element.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the third data packet detection rule is that the intermediate session management network element adds the tunnel of the target offload user plane network to the fourth data packet detection rule according to the seventh instruction information
  • the endpoint identifier and the IP address of the target offload user plane network are obtained
  • the third packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and the tunnel endpoint identifier of the target access network device to the fourth packet forwarding rule according to the seventh instruction information.
  • the IP address of the target access network device is obtained.
  • the third data packet detection rule is that the intermediate session management network element adds the source offload user plane network element's tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and target address of the target offloading user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the IP address of the offload user plane network element is obtained.
  • a session management network element in a tenth aspect, includes a transceiver module, and the transceiver module is configured to receive first indication information from an intermediate session management network element.
  • the first indication information is used to indicate that the intermediate session management network element has The target offload user plane NE and target user plane NE are inserted, and the source offload user plane NE and source user plane NE are deleted.
  • the transceiver module is configured to send second indication information to the intermediate session management network element according to the first indication information, and the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the transceiver module is configured to send fourth indication information to the intermediate session management network element, the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet, and the fourth indication information is that the session management network element knows that the target application network element has completed Instructions sent after switching.
  • the transceiver module is further configured to send the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • a user plane network element in an eleventh aspect, includes a transceiver module, and the transceiver module is configured to receive a first data packet forwarding control protocol request message from an intermediate session management network element, and the first data packet forwarding control protocol request message is provided.
  • the request message includes the first data packet detection rule and the first data packet forwarding rule.
  • the first data packet detection rule is the rule corresponding to the source offload user plane network element detecting data packets from the target offload user plane network element
  • the first data packet forwarding rule is source offload The user plane network element forwards the rules corresponding to the data packets from the target offloading user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the detection of data packets from the target access network device by the target offload user plane network element
  • the first data packet forwarding rule is the target offload user plane rule.
  • the transceiver module is further configured to receive the first packet forwarding control protocol request message from the intermediate session management network element, the first packet forwarding control protocol request message includes the first packet detection rule and the first packet forwarding rule.
  • the first data packet detection rule is the rule corresponding to the source offload user plane network element detecting data packets from the target offload user plane network element
  • the first data packet forwarding rule is source offload The user plane network element forwards the rules corresponding to the data packets from the target offloading user plane network element to the source user plane network element.
  • the first data packet detection rule is the rule corresponding to the detection of data packets from the target access network device by the target offload user plane network element
  • the first data packet forwarding rule is the target offload user plane rule.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained.
  • the first data packet detection rule is that the intermediate session management network element adds the source offload user plane network element’s tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier of the source user plane network element and the source user to the second data packet forwarding rule according to the sixth instruction information. Obtain the IP address of the plane network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • a user plane network element in a twelfth aspect, includes a transceiver module, and a transceiver module for receiving a third data packet forwarding control protocol request message from an intermediate session management network element, and a third data packet forwarding control protocol request message.
  • the request message includes a third data packet detection rule and a third data packet forwarding rule.
  • the third data packet detection rule is the rule corresponding to the source offload user plane network element detecting a data packet from a remote user plane network element, and the third data packet forwarding rule is source offload The user plane network element forwards the corresponding rule for the data packet from the remote user plane network element to the target offload user plane network element; or, the third data packet detection rule is that the source offload user plane network element detects the data from the source user plane network element.
  • the rule corresponding to the packet, the third data packet forwarding rule is a rule corresponding to forwarding the data packet from the source user plane network element to the target offload user plane network element by the source offload user plane network element.
  • the third data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the source offload user plane network element
  • the third data packet forwarding rule is the target offload The user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the third data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information
  • the identity and IP address of the target access network device are obtained.
  • the third data packet detection rule is that the intermediate session management network element adds the source offload user plane network element's tunnel endpoint identifier and The IP address of the source offloading user plane network element is obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint identifier and target address of the target offloading user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the IP address of the offload user plane network element is obtained.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • a communication device including a processor, a memory, an input interface, and an output interface.
  • the input interface is used to receive information from other communication devices other than the communication device
  • the output interface is used to send information to other communication devices other than the communication device.
  • Other communication devices output information
  • the processor invokes the computer program stored in the memory to implement the method of any one of the first aspect or the second aspect or the third aspect or the fourth aspect or the fifth aspect.
  • the communication device may be a chip or a device including a chip that implements the method in any one of the first aspect, the second aspect, or the third aspect, or the fourth aspect or the fifth aspect.
  • a computer-readable storage medium is provided.
  • a computer program is stored in the computer-readable storage medium.
  • the computer program is run, the first aspect or the second aspect or the third aspect or the fourth aspect or The method of any one of the fifth aspect.
  • a chip in a fifteenth aspect, includes at least one processor and an interface, the processor is used to read and execute instructions stored in the memory, and when the instructions are executed, the chip performs as described in the first aspect or the second aspect or The method of any one of the third aspect or the fourth aspect or the fifth aspect.
  • a computer program product containing instructions, when it is executed on a computer, the method of any one of the first aspect or the second aspect or the third aspect or the fourth aspect or the fifth aspect is executed .
  • a communication system includes one or more of the following: an intermediate session management network element, a session management network element, and a user plane network element.
  • the user plane network element includes one or more of the following: a target user plane network element, a source offload user plane network element, and a target offload user plane network element.
  • a communication system in an eighteenth aspect, includes an intermediate session management network element, a session management network element, and a user plane network element, and the intermediate session management network element is used to perform the method described in any one of the first aspect
  • the session management network element is configured to execute the method described in any one of the third aspect
  • the user plane network element is configured to execute the method described in any one of the fourth aspect.
  • a nineteenth aspect provides a communication system, the communication system includes an intermediate session management network element and a user plane network element, the intermediate session management network element is used to perform the method described in the second aspect, and the user plane network element is used to perform the first method The method described in any one of the five aspects.
  • Fig. 1 is the infrastructure of the communication system provided by the embodiment of the present application.
  • FIG. 2A is a schematic diagram of a 5G network architecture based on a service architecture
  • FIG. 2B is a schematic diagram of a 5G network architecture based on a point-to-point interface
  • FIG. 3 is a schematic diagram of a hardware structure applicable to a communication device provided by an embodiment of the present application
  • FIG. 4 is a schematic flowchart of a method for transmitting indication information provided in an embodiment of the present application
  • FIG. 5 is a schematic flowchart of a message transmission method provided by an embodiment of the present application.
  • FIG. 6A is a schematic flowchart of another message transmission method provided by the embodiment of the present application.
  • FIG. 6B is a schematic flowchart of another message transmission method provided by the embodiment of the present application.
  • FIG. 6C is a schematic flowchart of another message transmission method provided by the embodiment of the present application.
  • FIG. 7A is a schematic flowchart of another message transmission method provided by the embodiment of the present application.
  • FIG. 7B is a schematic flowchart of another message transmission method provided by the embodiment of the present application.
  • FIG. 7C is a schematic flowchart of another message transmission method provided in the embodiment of the present application.
  • FIG. 8 is a schematic structural diagram of a communication device provided by an embodiment of the present application.
  • At least one of the following or similar expressions refer to any combination of these items, including any combination of single or plural items.
  • at least one item (piece) of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, where a, b, c can be one or more .
  • words such as “first” and “second” are used to distinguish network elements from identical or similar items with basically the same functions . Those skilled in the art can understand that words such as “first” and “second” do not limit the number and execution order, and words such as “first” and “second” do not necessarily limit the difference.
  • references to "one embodiment” or “some embodiments” and the like described in the embodiments of the present application mean that specific features, structures or characteristics described in connection with the embodiments are included in one or more embodiments of the present application.
  • appearances of the phrases “in one embodiment,” “in some embodiments,” “in other embodiments,” “in other embodiments,” etc. in various places in this specification are not necessarily All refer to the same embodiment, but mean “one or more but not all embodiments” unless specifically stated otherwise.
  • the terms “including”, “comprising”, “having” and variations thereof mean “including but not limited to”, unless specifically stated otherwise.
  • FIG. 1 is a basic architecture of a communication system provided by an embodiment of the present application.
  • the communication system may include one or more of the following network elements: an intermediate session management network element, a session management network element, a user plane network element, an access network device, a terminal device, and a mobility management network element , the application network element and the data network (data network, DN) connected to the operator network, the terminal device can send data packets to the data network through the access network device and the user plane network element, and receive data packets from the data network.
  • the data packet may be service data.
  • FIG. 1 is only a schematic diagram, and does not constitute a limitation on applicable scenarios of the technical solution provided in the present application.
  • the intermediate session management network element selects the distribution user plane network element and the local user plane network element that provide the distribution function. It can be understood that in the process of terminal equipment movement, such as Xn handover, N2 handover, service request and tracking area update, the intermediate session management network element can choose to offload the user plane network element and local user according to the location of the terminal equipment. network elements, etc.
  • the intermediate session management network element may be an intermediate session management function (intermediate session management function, I-SMF) network element.
  • I-SMF intermediate session management function
  • the intermediate session management network element may still be It is an I-SMF network element, or may have other names, which are not limited in this application.
  • the session management network element is mainly used for session management in the mobile network, such as session establishment, modification, and release.
  • Specific functions include assigning an Internet Protocol (internet protocol, IP) address to a terminal device, selecting a remote user plane network element that provides a packet forwarding function, and the like.
  • IP Internet Protocol
  • the session management network element may be a session management function (session management function, SMF) network element, and in a future communication system (such as a 6G communication system), the session management network element may still be an SMF network element, or It can also have other names, which are not limited by this application.
  • the user plane network element is mainly used to process user packets, such as forwarding, charging, lawful interception, etc., and can be a remote user plane network element or a local user plane network element.
  • the remote user plane network element or the local user plane network element can be a protocol data unit session anchor (PDU session anchor, PSA).
  • PDU session anchor protocol data unit session anchor
  • PSA protocol data unit session anchor
  • the deployment location of the remote user plane network element or the local user plane network element is different, such as the local user plane network element
  • the network element is selected by the intermediate session management network element and provides forwarding of user packets, and the remote user plane network element is selected by the session management network element and provides forwarding of user packets.
  • the user plane network element may also be used to offload user packets, and may be a offload user plane network element, and the offload user plane network element may be an uplink splitter or a split point.
  • the user plane network element may be a user plane function (UPF) network element
  • UPF user plane function
  • future communication system such as a 6G communication system
  • the user plane network element may still be a UPF network element, or It can also have other names, which are not limited by this application. It can be understood that, in this application, both the source user plane network element and the target user plane network element are local user plane network elements, and both the source offload user plane network element and the target offload user plane network element are offload user plane network elements.
  • the source user plane network element can be the local user plane network element determined by the intermediate session management network element according to the position of the terminal device cell before reselection
  • the target user plane network element can be the intermediate session management network element after the terminal device cell reselection
  • the target user plane network element can be the local user plane network element determined by the intermediate session management network element according to the position of the terminal equipment cell after handover
  • the source offload user plane network element can be the intermediate
  • the access network device is an entity on the network side for sending signals, or receiving signals, or sending signals and receiving signals.
  • the access network device may be a device deployed in a radio access network (radio access network, RAN) to provide a wireless communication function for a terminal device, such as a transmission reception point (transmission reception point, TRP), a base station, various forms of control node.
  • a network controller a wireless controller, a wireless controller in a cloud radio access network (cloud radio access network, CRAN) scenario, and the like.
  • the access network equipment may be various forms of macro base stations, micro base stations (also called small cells), relay stations, access points (access point, AP), radio network controllers (radio network controller, RNC), Node B (node B, NB), base station controller (base station controller, BSC), base transceiver station (base transceiver station, BTS), home base station (for example, home evolved nodeB, or home node B, HNB), baseband unit (baseBand unit, BBU), transmitting point (transmitting point, TP), mobile switching center), etc., can also be the antenna panel of the base station.
  • the control node can connect multiple base stations, and configure resources for multiple terminals under the coverage of multiple base stations.
  • the names of the equipment with base station functions may be different.
  • it can be a gNB in 5G, or a network-side device in a network after 5G, or an access network device in a future evolved public land mobile network (PLMN) network.
  • PLMN public land mobile network
  • the access network device may also include a central unit (central unit, CU) and a distributed unit (distributed unit, DU) integrated on the gNB.
  • the access network device may be a source access network device or a target access network device.
  • the source access network device is the access network device before the cell reselection of the terminal device
  • the target access network device is the access network device after the cell reselection of the terminal device.
  • the terminal device is an entity on the user side for receiving signals, or sending signals, or receiving signals and sending signals.
  • Terminal equipment is used to provide one or more of voice services and data connectivity services to users.
  • the terminal device may be a device that includes a wireless transceiver function and can cooperate with the access network device to provide communication services for users.
  • the terminal equipment may refer to a user equipment (user equipment, UE), an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a terminal, a wireless communication device, a user agent, or user device.
  • the terminal device can also be a drone, an Internet of Things (Internet of Things, IoT) device, a station (station, ST) in a WLAN, a cellular phone (cellular phone), a smart phone (smart phone), a cordless phone, a wireless data card , Tablet PC, Session Initiation Protocol (SIP) Phone, Wireless Local Loop (WLL) Station, Personal Digital Assistant (PDA) Device, Laptop Computer , machine type communication (machine type communication, MTC) terminals, handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices (also known as wearable smart devices), Virtual reality (virtual reality, VR) terminal, augmented reality (augmented reality, AR) terminal, wireless terminal in industrial control (industrial control), wireless terminal in self driving (self driving), remote medical (remote medical) Wireless terminals in smart grid, wireless terminals in transportation safety, wireless terminals in smart city, wireless terminals in smart home, etc.
  • IoT Internet of Things
  • IoT Internet
  • the terminal device may also be a device to device (device to device, D2D) device, for example, an electric meter, a water meter, and the like.
  • the terminal device may also be a terminal in a 5G system, or a terminal in a next-generation communication system, which is not limited in this embodiment of the present application.
  • the mobility management network element has one or more of the following functions: registration, security authentication and key agreement for terminal equipment in the mobile network, maintenance of non-access stratum (Non-Access Stratum, NAS) connection, Mobility management, routing signaling between terminal equipment and other network elements. For example, routing a session management (session management, SM) message between a terminal device and a session management network element.
  • Namf is a service-based interface provided by mobility management network elements, and mobility management network elements can communicate with other network functions through Namf. It can be understood that this application does not limit the name of the mobility management network element.
  • the mobility management network element may be called an AMF network element.
  • the application network element can provide the service data of various applications to the control plane function of the communication network of the operator, or obtain the data information and control information of the network from the control plane function of the communication network, or provide the terminal equipment with the service data of various applications. business data.
  • the application network element can be an application function (application function, AF) network element, and in the future communication system (such as 6G communication system), the application function can still be an AF network element, or it can also have other names , this application is not limited.
  • the data network is mainly used to provide data transmission services for terminal devices.
  • the data network can be a private network, such as a local area network, or a public data network (public data network, PDN) network, such as the Internet (Internet), or a proprietary network jointly deployed by operators, such as a configured IP multimedia network subnet.
  • PDN public data network
  • Internet Internet
  • proprietary network jointly deployed by operators, such as a configured IP multimedia network subnet.
  • System IP multimedia core network subsystem, IMS
  • the intermediate session management network element may be deployed independently or integrated into the session management network element, which is not limited in this application.
  • the source offload user plane network element and the source user plane network element can be deployed together or separately.
  • the service areas can be different; the target offload user plane network element and the target user plane network element can be deployed together.
  • the service areas may be different, which is not limited in this application.
  • FIG. 2A is a schematic diagram of a 5G network architecture based on a service-based architecture.
  • the 5G network architecture shown in FIG. 2B may include a data network and an operator network. The functions of some of the network elements are briefly introduced and described below.
  • the operator network may include one or more of the following network elements: authentication server function (Authentication Server Function, AUSF) network element, network exposure function (network exposure function, NEF) network element, policy control function (policy control function, PCF) network element, unified data management (unified data management, UDM) network element, unified database (Unified Data Repository, UDR), network storage function (Network Repository Function, NRF) network element, AF network element, access and Mobility management function (access and mobility management function, AMF) network element, SMF network element, RAN device and UPF network element, network slice selection function (Network Slice Selection Function, NSSF) network element (not shown in Figure 2A or Figure 2B out) etc.
  • network elements or devices other than radio access network devices may be referred to as core network elements or core network devices.
  • the wireless access network equipment can be a base station (base station), an evolved base station (evolved NodeB, eNodeB), TRP, a next generation base station (next generation NodeB, gNB) in a 5G mobile communication system, and a next generation node in a 6G mobile communication system.
  • the radio access network equipment can be a macro base station, a micro base station or an indoor station, or a relay node or a donor node.
  • the specific technology adopted by the radio access network equipment in the embodiments of this application There is no limit to the specific device form.
  • a terminal communicating with the RAN may also be referred to as terminal equipment, UE, mobile station, mobile terminal, and the like.
  • Terminals can be widely used in various scenarios, for example, device-to-device (device-to-device, D2D), vehicle-to-everything (V2X) communication, MTC, Internet of Things (IOT), virtual reality, Augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc.
  • Terminals can be mobile phones, tablet computers, computers with wireless transceiver functions, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, etc.
  • the embodiment of the present application does not limit the specific technology and specific equipment form adopted by the terminal.
  • Base stations and terminals can be fixed or mobile. Base stations and terminals can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed on aircraft, balloons and artificial satellites in the air. The embodiments of the present application do not limit the application scenarios of the base station and the terminal.
  • the AMF network element performs functions such as mobility management and access authentication/authorization. In addition, it is also responsible for transferring user policies between the terminal and the PCF.
  • the SMF network element performs functions such as session management, execution of control policies issued by PCF, selection of UPF, and assignment of IP addresses to terminals.
  • the UPF network element as the interface UPF with the data network, completes functions such as user plane data forwarding, session/flow-based charging statistics, and bandwidth limitation.
  • the UDM network element performs functions such as managing subscription data and user access authorization.
  • UDR implements the access function of contract data, policy data, application data and other types of data.
  • NEF network elements are used to support the opening of capabilities and events.
  • the AF network element transmits the requirements from the application side to the network side, such as QoS requirements or user status event subscription.
  • the AF may be a third-party functional entity, or an application service deployed by an operator, such as an IMS voice call service.
  • the PCF network element is responsible for policy control functions such as charging for sessions and service flow levels, QoS bandwidth guarantee, mobility management, and terminal policy decision-making.
  • the NRF network element can be used to provide a network element discovery function, and provide network element information corresponding to the network element type based on the request of other network elements.
  • NRF also provides network element management services, such as network element registration, update, de-registration, network element status subscription and push, etc.
  • the AUSF network element is responsible for authenticating users to determine whether users or devices are allowed to access the network.
  • the NSSF network element is used to select a network slice and count users in the network slice.
  • DN is a network outside the operator's network.
  • the operator's network can access multiple DNs, and various services can be deployed on the DN, which can provide data and/or voice services for terminals.
  • DN is a private network of a smart factory.
  • the sensors installed in the workshop of the smart factory can be terminals, and the control server of the sensors is deployed in the DN, and the control server can provide services for the sensors.
  • the sensor can communicate with the control server, obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions.
  • DN is an internal office network of a certain company.
  • the mobile phone or computer of the employee of the company can be a terminal, and the mobile phone or computer of the employee can access information and data resources on the internal office network of the company.
  • Nausf, Nnef, Npcf, Nudm, Naf, Namf, and Nsmf are the service interfaces provided by the above-mentioned AUSF, NEF, PCF, UDM, AF, AMF, and SMF, respectively, and are used to call corresponding service operations.
  • N1, N2, N3, N4, and N6 are interface serial numbers. The meanings of these interface serial numbers may refer to the meanings defined in the third generation partnership project (3rd generation partnership project, 3GPP) standard agreement, and no limitation is made here.
  • FIG. 2B is a schematic diagram of a 5G network architecture based on a point-to-point interface.
  • the interface between each control plane network element in FIG. 2A is a service interface
  • the interface between each control plane network element in FIG. 2B is a point-to-point interface.
  • N1 the interface between the AMF and the terminal, which can be used to transmit QoS control rules and the like to the terminal.
  • N2 the interface between the AMF and the RAN, which can be used to transfer radio bearer control information from the core network side to the RAN.
  • N3 the interface between the RAN and the UPF, mainly used to transfer the uplink and downlink user plane data between the RAN and the UPF.
  • N4 The interface between SMF and UPF, which can be used to transfer information between the control plane and the user plane, including controlling the distribution of forwarding rules, QoS control rules, traffic statistics rules, etc. Information reporting.
  • N5 the interface between the AF and the PCF, which can be used for sending application service requests and reporting network events.
  • N6 the interface between UPF and DN, used to transfer the uplink and downlink user data flow between UPF and DN.
  • N7 the interface between PCF and SMF, which can be used to deliver protocol data unit (protocol data unit, PDU) session granularity and service data flow granularity control policy.
  • protocol data unit protocol data unit
  • PDU protocol data unit
  • N8 The interface between AMF and UDM, which can be used for AMF to obtain subscription data and authentication data related to access and mobility management from UDM, and for AMF to register terminal current mobility management related information with UDM.
  • N9 a user plane interface between UPF and UPF, used to transmit uplink and downlink user data flows between UPFs.
  • N10 the interface between SMF and UDM, which can be used for SMF to obtain session management-related subscription data from UDM, and for SMF to register terminal current session-related information with UDM.
  • N11 the interface between SMF and AMF, which can be used to transfer PDU session tunnel information between RAN and UPF, transfer control messages sent to terminals, transfer radio resource control information sent to RAN, etc.
  • N12 the interface between AMF and AUSF, which can be used for AMF to initiate an authentication process to AUSF, which can carry a subscription concealed identifier (SUCI) as a subscription identifier;
  • SUCI subscription concealed identifier
  • N13 the interface between UDM and AUSF, which can be used for AUSF to obtain user authentication vector from UDM to execute the authentication process.
  • N15 the interface between the PCF and the AMF, which can be used to issue terminal policies and access control-related policies.
  • N35 the interface between UDM and UDR, which can be used for UDM to obtain user subscription data information from UDR.
  • N36 the interface between the PCF and the UDR, which can be used for the PCF to obtain policy-related subscription data and application data-related information from the UDR.
  • the above-mentioned network element or function may be a network element in a hardware device, or a software function running on dedicated hardware, or a virtualization function instantiated on a platform (for example, a cloud platform).
  • a platform for example, a cloud platform.
  • the foregoing network element or function may be implemented by one device, or jointly implemented by multiple devices, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.
  • the session management network element, user plane network element, and policy control network element in this application can be the SMF, UPF, and PCF in Figure 2A or Figure 2B, respectively, or they can be the above-mentioned SMF, UPF, and PCF in future communications such as 6G networks.
  • a network element with a function which is not limited in this application.
  • SMF, UPF, and PCF are respectively used as an example of a session management network element, a user plane network element, and a policy control network element for description.
  • the above-mentioned network element or function may be a network element in a hardware device, or a software function running on dedicated hardware, or a virtualization function instantiated on a platform (for example, a cloud platform).
  • the above-mentioned network elements or functions can be divided into one or more services, and further, there may also be services that exist independently of network functions.
  • an instance of the above-mentioned function, or an instance of a service included in the above-mentioned function, or a service instance existing independently of the network function may be referred to as a service instance.
  • the technical solutions provided by the embodiments of the present application are applicable to various system architectures.
  • the network architecture and business scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute limitations on the technical solutions provided by the embodiments of the present application.
  • the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.
  • each network element (such as an intermediate session management network element, a session management network element, a user plane network element, an access network device, a terminal device, a mobility management network element, an application network element, etc.) in FIG. It may be implemented by one device, or jointly implemented by multiple devices, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application. It can be understood that the above function can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualization function instantiated on a platform (for example, a cloud platform).
  • a platform for example, a cloud platform
  • FIG. 3 is a schematic diagram of a hardware structure applicable to a communication device provided by an embodiment of the present application.
  • the communication device 300 includes at least one processor 301 , a communication line 302 and at least one communication interface 304 .
  • the processor 301 can be a general-purpose central processing unit (central processing unit, CPU), a microprocessor, a specific application integrated circuit (application-specific integrated circuit, ASIC), or one or more for controlling the execution of the application program program integrated circuit.
  • CPU central processing unit
  • ASIC application-specific integrated circuit
  • Communication line 302 may include a path for passing information between the above-described components.
  • the communication interface 304 is any device such as a transceiver (such as an antenna) for communicating with other devices or communication networks, such as Ethernet, RAN, wireless local area networks (wireless local area networks, WLAN), etc.
  • a transceiver such as an antenna
  • WLAN wireless local area networks
  • the communication device 300 further includes a memory 303
  • the memory 303 may be a read-only memory (read-only memory, ROM) or other types of static storage devices that can store static information and instructions, random access memory (random access memory) , RAM) or other types of dynamic storage devices that can store information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory , CD-ROM) or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disc storage media or other magnetic storage devices, or capable of carrying or storing Desired program code in the form of a data structure and any other medium capable of being accessed by a computer, but not limited thereto.
  • ROM read-only memory
  • RAM random access memory
  • EEPROM electrically erasable programmable read-only memory
  • CD-ROM compact disc read-only memory
  • optical disc storage including compact discs, laser discs, optical discs, digital
  • the memory may exist independently and be connected to the processor through the communication line 302 . Memory can also be integrated with the processor.
  • the memory provided by the embodiment of the present application may generally be non-volatile.
  • the memory 303 is used to store computer-executed instructions for implementing the solution of the present application, and the execution is controlled by the processor 301 .
  • the processor 301 is configured to execute computer-executed instructions stored in the memory 303, so as to implement the methods provided in the following embodiments of the present application.
  • the computer-executed instructions in the embodiments of the present application may also be referred to as application program codes, which is not specifically limited in the embodiments of the present application.
  • the processor 301 may include one or more CPUs, such as CPU0 and CPU1 in FIG. 3 .
  • the communications apparatus 300 may include multiple processors, for example, the processor 301 and the processor 307 in FIG. 3 .
  • Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor.
  • a processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (eg, computer program instructions).
  • the communication apparatus 300 may further include an output device 305 and an input device 306 .
  • Output device 305 is in communication with processor 301 and can display information in a variety of ways.
  • the output device 305 may be a liquid crystal display (liquid crystal display, LCD), a light emitting diode (light emitting diode, LED) display device, a cathode ray tube (cathode ray tube, CRT) display device, or a projector (projector) wait.
  • the input device 306 communicates with the processor 301 and can receive user input in various ways.
  • the input device 306 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.
  • the aforementioned communication device 300 may be a general-purpose device or a special-purpose device.
  • the communication device 300 may be a desktop computer, a portable computer, a network server, a palmtop computer, a mobile phone, a tablet computer, a wireless terminal device, an embedded device or a device having a structure similar to that shown in FIG. 3 .
  • the embodiment of the present application does not limit the type of the communication device 300 .
  • FIG. 4 is a schematic flowchart of a method for transmitting indication information provided by an embodiment of the present application. As shown in Figure 4, the method includes but is not limited to the following steps:
  • the intermediate session management network element sends the first indication information to the session management network element, the first indication information is used to indicate that the intermediate session management network element has inserted the target offload user plane network element and the target user plane network element, and has deleted the source offload User plane network element and source user plane network element.
  • the session management network element receives the first indication information from the intermediate session management network element.
  • the first indication information is used to indicate that the intermediate session management network element has been inserted into the target offload user plane network element and the target user plane network element, and that the source offload user plane network element and the source user plane network element have been deleted. Yuan. That is, the intermediate session management network element has selected the target offload user plane network element and the target user plane network element according to the current location information of the terminal equipment, and respectively established data packets of the terminal equipment with the target offload user plane network element and the target user plane network element. Forwarding control protocol (packet forwarding control protocol, PFCP) session. At the same time, the intermediate session management network element needs to wait for an instruction from the session management network element, so as to delete and source offload the PFCP session between the user plane network element and the terminal device of the source user plane network element.
  • PFCP Packet forwarding control protocol
  • the first indication information may be included in the first PDU session update request message, and the first PDU session update request message is used to instruct the session management network element to update the first PDU session.
  • the first PDU session update request message may also include the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element.
  • the first PDU session update request message may be Nsmf_PDUSession_Update request.
  • the session management network element sends second indication information to the intermediate session management network element according to the first indication information, and the second indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the intermediate session management network element receives the second indication information from the session management network element.
  • step 402 can be understood as: the session management network element can learn that the intermediate session management network element has been inserted into the target offload user plane network element and the target user plane network element according to the first indication information, that is, the session management network element can according to the first
  • the indication information is used to know that the local user plane network element changes.
  • the change of the local user plane network element may lead to the handover of the application network element, that is, the change of the local user plane network element may cause the source application network element to switch to the target application network element.
  • the session management network element can first send the second indication information to the intermediate session management network element, so that the target user plane network element can first cache the uplink data Bag.
  • the second indication information may be a value of the first field, and the value of the first field may be a value of at least one bit or an enumerated value, which is not limited here.
  • the first field can be implemented in any of the following ways:
  • the first field may be a new field or an original field in the first PDU session update response message.
  • the first PDU session update response message is used to indicate that the session management network element successfully updates the first PDU session
  • the first PDU session update response message may be Nsmf_PDUSession_Update response.
  • the first field may be a newly added field or an original field in the first information.
  • the first information is used to instruct to establish the PFCP session between the intermediate session management network element and the target user plane network element, and the first information may be N4 information.
  • the first information may be included in the first PDU session update response message.
  • the first field may be a field in the first cell.
  • the first information element is a forwarding action information element in the fifth data packet forwarding rule, or an information element with similar definition or function, or an information element with an extension field, which is not limited here.
  • the fifth data packet forwarding rule may be a rule corresponding to forwarding the data packet from the target offloading user plane network element to the data network by the target user plane network element.
  • the fifth data packet forwarding rule may be included in the first information.
  • the value of the first field when the value of the first field is 1, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the first field is 0, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no Meaning; or, when the value of the first field is 0, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the first field is 1, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no The meaning is not limited here.
  • the value of the first field may be the value of the cache bit in the first cell, the value of the cache bit may be the first value, and the first value may be 0, 1 or other values, which are not described here Do limit.
  • the intermediate session management network element sends third indication information to the target user plane network element according to the second indication information, where the third indication information is used to instruct the target user plane network element to cache the uplink data packet.
  • the target user plane network element receives third indication information from the intermediate session management network element.
  • step 403 can be replaced by: the intermediate session management network element sends the second instruction information to the target user plane network element, wherein the second instruction information can be included in the packet forwarding control protocol session update request message (PFCP session modification request) , the packet forwarding control protocol session update request message is used to instruct the target user plane network element to update the PFCP session of the terminal device.
  • PFCP session modification request packet forwarding control protocol session update request message
  • the third indication information may be a value of the second field, and the value of the second field may be a value of at least one bit or an enumeration value, which is not limited here.
  • the second field can be a field in the second information element, and the second information element is a forwarding action information element in the fifth data packet forwarding rule, or an information element with similar definition or function, or an information element of an extension field, which is not done here limit.
  • the intermediate session management network element can receive the fifth data packet forwarding rule from the session management network element, therefore, the intermediate session management network element can send the target user
  • the plane network element sends the fifth data packet forwarding rule
  • the fifth data packet forwarding rule may be included in the data packet forwarding control protocol session update request message
  • the data packet forwarding control protocol session update request message is used to instruct the target user plane network element to update the terminal The PFCP session of the device.
  • the first information element may be the same as or different from the second information element, which is not limited here.
  • the first field may be the same as or different from the second field, which is not limited here.
  • the value of the second field when the value of the second field is 1, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the second field is 0, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no meaning; or, when the value of the second field is 0, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the second field is 1, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no The meaning is not limited here.
  • the session management network element sends fourth indication information to the intermediate session management network element.
  • the fourth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the fourth indication information is that the session management network element learns that the target application network element has Instructions sent after switching is complete.
  • the intermediate session management network element receives fourth indication information from the session management network element.
  • the fourth indication information is the indication information sent by the session management network element after learning that the target application network element has completed the handover, which can be understood as: the fourth indication information is the indication sent by the session management network element after receiving the confirmation message from the target application network element information, the confirmation message is used to indicate that the target application network element has completed the handover.
  • the fourth indication information may be included in the second PDU session update request message, and the second PDU session update request message is used to instruct the intermediate session management network element to update the second PDU session, and the second PDU session update request message may be Nsmf_PDUSession_Update request.
  • the fourth indication information may be a value of the third field, and the value of the third field may be a value of at least one bit or an enumerated value, which is not limited here.
  • the third field can be implemented in any of the following ways:
  • the third field may be a newly added field or an original field in the second PDU session update request message.
  • the second PDU session update request message may be Nsmf_PDUSession_Update request.
  • the third field may be a newly added field or an original field in the second information.
  • the second information is used to indicate to update the PFCP session between the intermediate session management network element and the target user plane network element, and the second information may be N4 information.
  • the second information may be included in the second PDU session update request message.
  • the third field may be a field in the third information element.
  • the third information element is a forwarding action information element in the sixth data packet forwarding rule, or an information element with a similar definition or function, or an information element with an extended field, which is not limited here.
  • the sixth data packet forwarding rule may be a rule corresponding to forwarding the data packet from the target offloading user plane network element to the data network by the target user plane network element.
  • the sixth data packet forwarding rule may be included in the second information.
  • the value of the third field when the value of the third field is 1, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the third field is 0, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no meaning; or, when the value of the third field is 0, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the third field is 1, it is used to indicate that the target user plane network element does not cache the uplink data packet or no The meaning is not limited here.
  • the value of the third field may be the value of the cache bit in the third cell
  • the value of the cache bit may be the second value
  • the second value may be 0, 1 or other values, which are not described here Do limit.
  • the sixth data packet forwarding rule may be the same as the fifth data packet forwarding rule.
  • the intermediate session management network element sends fifth indication information to the target user plane network element according to the fourth indication information, where the fifth indication information is used to instruct the target user plane network element to forward the uplink data packet.
  • the target user plane network element receives fifth indication information from the intermediate session management network element.
  • step 404 the fourth indication information is the same as the fifth indication information. That is, step 404 may be replaced by: the intermediate session management network element sends fourth indication information to the target user plane network element, wherein the fourth indication information may be included in the packet forwarding control protocol session update request message, and the data packet forwarding control protocol The session update request message is used to instruct the target user plane network element to update the PFCP session of the terminal device.
  • the fifth indication information may be a value of the fourth field, and the value of the fourth field may be a value of at least one bit or an enumeration value, which is not limited here.
  • the fourth field can be a field in the fourth information element, and the fourth information element is the forwarding action information element in the sixth data packet forwarding rule, or an information element with similar definition or function, or an information element of an extension field, which is not done here limit.
  • the intermediate session management network element can receive the sixth data packet forwarding rule from the session management network element, therefore, the intermediate session management network element can send the target user
  • the plane network element sends the sixth data packet forwarding rule
  • the sixth data packet forwarding rule may be included in the data packet forwarding control protocol session update request message
  • the data packet forwarding control protocol session update request message is used to instruct the target user plane network element to update the terminal The PFCP session of the device.
  • the third information element may be the same as or different from the fourth information element, which is not limited here.
  • the third field may be the same as or different from the fourth field, which is not limited here.
  • the value of the fourth field when the value of the fourth field is 1, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the fourth field is 0, it is used to indicate that the target user plane network element does not cache the uplink data packet or has no meaning; or, when the value of the fourth field is 0, it is used to indicate that the target user plane network element caches the uplink data packet, and when the value of the fourth field is 1, it is used to indicate that the target user plane network element does not cache the uplink data packet or no
  • the meaning is not limited here.
  • the intermediate session management network element sends the first indication information to the session management network element, so that the session management network element can know that the intermediate session management network element has been inserted into the target distribution user plane network element and the target user plane network element. element, and the source offload user plane network element and the source user plane network element have been deleted, so that the intermediate session management network element can send the third indication information to the target user plane network element according to the second indication information from the session management network element, and then Let the target user plane network element cache the uplink data packet according to the third indication information.
  • the session management network element when the session management network element knows that the target application network element has completed the handover, it can send the fourth indication information to the intermediate session management network element, so that the intermediate session management network element sends the fifth indication information to the target user plane network element according to the fourth indication information. indication information, and then let the target user plane network element forward the uplink data packet according to the fifth indication information. Understandably, since the target user plane network element does not forward the uplink data packet before the target application network element completes the handover, but buffers the uplink data packet before the target application network element completes the handover, the uplink data packet is not forwarded, avoiding Uplink packet loss. In addition, since the target user plane network element forwards the uplink data packet after the target application network element completes the handover, the uplink data packet can be forwarded to the target application network element, which improves the continuity and reliability of data packet transmission.
  • the method may further include: the intermediate session management network element sends a first data packet forwarding control protocol request message to the user plane network element, and the first data packet forwarding control protocol request message includes the first data packet detection rule and the second data packet detection rule. A data packet forwarding rule.
  • the user plane network element receives the first data packet forwarding control protocol request message from the intermediate session management network element.
  • the first data packet detection rule is a rule corresponding to a source offload user plane network element detecting a data packet from a target offload user plane network element
  • the first data packet forwarding rule is The source offload user plane NE forwards to the source user plane NE the corresponding rules for packets from the target offload user plane NE
  • the first packet detection rule is the target offload user
  • the plane network element detects the rule corresponding to the data packet from the target access network device, and the first data packet forwarding rule is the rule corresponding to the data packet forwarded from the target access network device by the target offload user plane network element to the source offload user plane network element .
  • the first packet forwarding control protocol request message is used to instruct the user plane network element to establish or update the PFCP session of the terminal device.
  • the first data packet forwarding control protocol request message is used to instruct the source offload user plane network element to update the PFCP session of the terminal device, and the first data packet forwarding control protocol request message may be data Packet forwarding control protocol session update request message (PFCP session modification request);
  • the first packet forwarding control protocol request message may be a packet forwarding control protocol session update request message (PFCP session modification request) or a packet forwarding control protocol session update request message (PFCP session establishment request).
  • the user plane network element may also send the first data packet forwarding control protocol response message to the intermediate session management network element, and the first data packet forwarding control protocol response message is used for It is used to instruct the user plane network element to successfully establish or update the PFCP session of the terminal device.
  • the source offload user plane network element may also send the first data packet forwarding control protocol response message to the intermediate session management network element, the first data packet forwarding control protocol response message
  • the message is used to indicate that the source offloading user plane network element has successfully updated the PFCP session of the terminal device, and the first packet forwarding control protocol response message may be a packet forwarding control protocol session update response message (PFCP session modification response); the target offloading user plane network
  • the element After the element receives the first data packet forwarding control protocol request message, it can also send the first data packet forwarding control protocol response message to the intermediate session management network element, and the first data packet forwarding control protocol response message is used to indicate that the target offloads the user plane network.
  • the first packet forwarding control protocol response message can be a packet forwarding control protocol session update response message (PFCP session modification response) or a packet forwarding control protocol session establishment response message (PFCP session establishment response).
  • the first data packet forwarding control protocol response message is used to indicate that the target offloading user plane network element is successfully established The PFCP session of the terminal device; if the first data packet forwarding control protocol request message is used to instruct the target offloading user plane network element to update the PFCP session of the terminal device, the first data packet forwarding control protocol response message is used to instruct the target offloading user plane network element Successfully updated the PFCP session of the end device.
  • the first data packet detection rule is an uplink data packet detection rule
  • the first data packet forwarding rule is an uplink data packet forwarding rule
  • the first data packet forwarding control protocol request message may further include a third data packet detection rule and a third data packet forwarding rule.
  • the third data packet forwarding rule is a rule corresponding to the source offload user plane network element forwarding the data packet from the remote user plane network element to the target offload user plane network element; or,
  • the third data packet detection rule is the rule corresponding to the detection of data packets from the source user plane network element by the source offload user plane network element, and the third data packet forwarding rule is that the source offload user plane network element forwards the packet from the source offload user plane network element to the target offload user plane network element.
  • Rules corresponding to data packets of user plane network elements are possible.
  • the third data packet detection rule is the rule corresponding to the target offload user plane network element detecting the data packet from the source offload user plane network element
  • the third data packet forwarding rule is the target offload The user plane network element forwards the rules corresponding to the data packets from the source offload user plane network element to the target access network device.
  • the third data packet detection rule is a downlink data packet detection rule
  • the third data packet forwarding rule is a downlink data packet forwarding rule
  • the intermediate session management network element may send the first data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the first data packet forwarding control protocol request message Including the first data packet detection rule and the first data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the first data packet detection rule, and forwards the data according to the first data packet forwarding rule packet, which avoids the loss of the uplink data packet of the terminal equipment and improves the continuity and reliability of data packet transmission.
  • the method may further include: the intermediate session management network element receiving the second data packet detection rule, the second data packet forwarding rule and sixth indication information from the session management network element.
  • the session management network element sends the second data packet detection rule, the second data packet forwarding rule and the sixth indication information to the intermediate session management network element.
  • the intermediate session management network element before the intermediate session management network element sends the first data packet forwarding control protocol request message to the user plane network element, the intermediate session management network element receives the second data packet detection rule and the second data packet forwarding rule from the session management network element. Rules and Sixth Instructions.
  • the second data packet detection rule is a rule for detecting data packets from the target access network device
  • the second data packet forwarding rule is a rule for forwarding the data packets from the target access network device to the source distribution user plane network element
  • the second data packet detection rule is a rule for detecting data packets from the target offload user plane network element
  • the second data packet forwarding rule is a rule for forwarding data packets from the target offload user plane network element to the source user plane network element .
  • the second data packet detection rule and the second data packet forwarding rule may be included in the third information, and the third information may be N4 information. It can be understood that the third information is used to instruct the intermediate session management network element to delete or update the PFCP session with the source offload user plane network element; or, the third information is used to instruct the intermediate session management network element to establish a connection with the target offload user plane PFCP session between network elements.
  • the third information is used to instruct the intermediate session management network element to delete or update the PFCP session with the source offload user plane network element ; If the second data packet forwarding rule is a rule for forwarding data packets from the target offload user plane network element to the source user plane network element, the third information is used to instruct the intermediate session management network element to delete or update the user plane network element with the source offload user plane PFCP sessions between elements; if the second data packet detection rule is a rule for detecting data packets from the target access network device, the third information is used to indicate the connection between the establishment of the intermediate session management network element and the target offloading user plane network element PFCP session; if the second data packet forwarding rule is a rule for forwarding data packets from the target access network device to the source offload user plane network element, the third information is used to instruct the intermediate session management network element to establish and target offload user plane network PFCP session
  • the second data packet detection rule is an uplink data packet detection rule
  • the second data packet forwarding rule is an uplink data packet forwarding rule
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is a rule corresponding to the source offload user plane network element or target offload user plane network element detection data packet; the second data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is the rule corresponding to the source offload user plane network element detection data packet; the second data packet forwarding rule is the source offload user plane network element The rule corresponding to the meta-forwarding packet.
  • the sixth indication information is used to indicate one or more of the following: the second data packet detection rule is the rule corresponding to the target offload user plane network element detection data packet; the second data packet forwarding rule is the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the sixth indication information may be a value of the fifth field, and the value of the fifth field may be a value of at least one bit or an enumerated value, which is not limited here.
  • the fifth field can be implemented in any of the following ways:
  • the fifth field may be a newly added field or an original field in the first PDU session update request message.
  • the fifth field may be a newly added field or an original field in the third information.
  • the fifth field may be a field in the fifth information element.
  • the fifth information element is a forwarding action information element in the second data packet detection rule or the second data packet forwarding rule, or an information element with a similar definition or function, or an information element with an extended field, which is not limited here.
  • the second data packet detection rule is a rule corresponding to the source offload user plane network element detection data packet
  • the second data packet forwarding rule is The rule corresponding to the data packet forwarded by the source offload user plane network element.
  • the value of the fifth field is 0, it is used to indicate one or more of the following: the second data packet detection rule is not corresponding to the source offload user plane network element detection packet.
  • the rule and the second data packet forwarding rule are not the rules corresponding to the data packet forwarded by the source offloading user plane network element, and have no meaning; or, when the value of the fifth field is 0, it is used to indicate one or more of the following: the second data packet
  • the detection rule is the rule corresponding to the detection data packet of the source offload user plane network element
  • the second data packet forwarding rule is the corresponding rule of the source offload user plane network element forwarding data packet.
  • the value of the fifth field is 1, it is used to indicate the following One or more items: the second data packet detection rule is not the rule corresponding to the source offload user plane network element detection packet, the second data packet forwarding rule is not the source offload user plane network element forwarding data packet corresponding rule, meaningless, here No restrictions.
  • the sixth indication information may be a forwarding tunnel rule indication.
  • the intermediate session management network element can receive the second data packet detection rule, the second data packet forwarding rule and the sixth indication information from the session management network element, so that the intermediate session management network element can know the following: One or more items: the second data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet, and the second data packet forwarding rule is the source offload user plane network element or the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the first data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the second data packet detection rule according to the sixth indication information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the first data packet forwarding rule is that the intermediate session management network element adds the tunnel of the source offloading user plane network element to the second data packet forwarding rule according to the sixth instruction information
  • the endpoint identifier and the IP address of the source offload user plane network element are obtained; if the user plane network element is a source offload user plane network element, the first data packet detection rule is that the intermediate session management network element is in the second data packet according to the sixth instruction information
  • the detection rule is obtained by adding the tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE.
  • the first data packet forwarding rule is that the intermediate session management network element forwards the second data packet according to the sixth instruction information
  • the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element are used to instruct the target offload user plane network element to receive the uplink service data packet.
  • the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element are used to instruct the source offload user plane network element to receive the uplink service data packet.
  • the sixth indication information may be "Y".
  • the second data packet detection rule and the second data packet forwarding rule described in Table 1 are for the session management network element to instruct the intermediate session management network element to establish a PFCP session with the target offloading user plane network element Included in the N4 information.
  • Table 1 shows the correspondence between data packet detection rules, data packet forwarding rules, and indication information.
  • UL PDR259 (identification of the second data packet detection rule), the tunnel endpoint identifier of the source offload user plane network element, and the IP address of the source offload user plane network element (the tunnel endpoint of the source offload user plane network element
  • the IP address of the identification and source splitting user plane network element is included in the first data packet forwarding rule), Access (source interface), N3 (source interface type), ULFAR 259 (identification of the second data packet forwarding rule), Core There is a corresponding relationship among (target interface), N9 (target interface type), and the sixth indication information.
  • the intermediate session management network element can add the tunnel endpoint identifier of the source offload user plane network element and the network address of the source offload user plane network element to the second data packet forwarding rule according to the sixth indication information. Protocol address, get the first data packet forwarding rule.
  • Table 1 Correspondence between packet inspection rules, packet forwarding rules, and indication information
  • the first packet forwarding rule since the first packet detection rule also includes the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element, the first packet forwarding rule also includes The tunnel endpoint identifier of the source offload user plane NE and the IP address of the source offload user plane NE enable the target offload user plane NE to The protocol address receives and detects the data packet, and establishes a tunnel according to the tunnel endpoint identifier of the source offload user plane NE, the IP address of the source offload user plane NE, and the source offload user plane NE, so that the data packet can be transmitted through the tunnel, avoiding The loss of uplink data packets of the terminal equipment.
  • the first data packet forwarding rule also includes the source user plane network element's The tunnel endpoint identifier and the IP address of the source user plane network element enable the source offload user plane network element to receive and detect the data packet according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, According to the tunnel endpoint identifier of the source user plane network element and the IP address of the source user plane network element, a tunnel is established with the source user plane network element, so that the data packets can be transmitted through the tunnel, and the loss of the uplink data packets of the terminal equipment is avoided.
  • FIG. 5 is a schematic flowchart of a message transmission method provided by an embodiment of the present application. As shown in Figure 5, the method includes but is not limited to the following steps:
  • the intermediate session management network element sends a third data packet forwarding control protocol request message to the user plane network element, and the third data packet forwarding control protocol request message includes a third data packet detection rule and a third data packet forwarding rule.
  • the user plane network element receives the third data packet forwarding control protocol request message from the intermediate session management network element.
  • the third packet forwarding control protocol request message is used to instruct the user plane network element to establish or update the PFCP session of the terminal device.
  • the third data packet forwarding control protocol request message is used to instruct the source offload user plane network element to update the PFCP session of the terminal device, and the third data packet forwarding control protocol request message may be data Packet forwarding control protocol session update request message (PFCP session modification request);
  • the third packet forwarding control protocol request message is used to instruct the target offload user plane network element to establish or update the terminal
  • the third packet forwarding control protocol request message can be a packet forwarding control protocol session update request message (PFCP session modification request) or a packet forwarding control protocol session establishment request message (PFCP session establishment request).
  • the user plane network element may also send a third data packet forwarding control protocol response message to the intermediate session management network element, and the third data packet forwarding control protocol response message is used for It is used to instruct the user plane network element to successfully establish or update the PFCP session of the terminal device.
  • the source offload user plane network element may also send a third data packet forwarding control protocol response message to the intermediate session management network element, and the third data packet forwarding control protocol response message
  • the message is used to indicate that the source offload user plane network element has successfully updated the PFCP session of the terminal device; after receiving the third data packet forwarding control protocol request message, the target offload user plane network element can also send the third data packet to the intermediate session management network element
  • the forwarding control protocol response message, the third data packet forwarding control protocol response message is used to indicate that the target offload user plane network element successfully establishes or updates the PFCP session of the terminal device, and the third data packet forwarding control protocol response message may be a data packet forwarding control protocol Session update response message (PFCP session modification response) or forwarding control protocol session establishment response message (PFCP session establishment response).
  • the third data packet forwarding control protocol response message is used to indicate that the target offloading user plane network element is successfully established PFCP session of the terminal device; if the third data packet forwarding control protocol request message is used to instruct the target offloading user plane network element to update the PFCP session of the terminal device, the third data packet forwarding control protocol response message is used to instruct the target offloading user plane network element Successfully updated the PFCP session of the end device.
  • the third data packet forwarding control protocol request message may further include the first data packet detection rule and the first data packet forwarding rule.
  • the first data packet forwarding control protocol request message and the third data packet forwarding control protocol request message may be the same message or different messages, which are not limited here. If the first data packet forwarding control protocol request message and the third data packet forwarding control protocol request message are the same message, the first data packet forwarding control protocol response message may be the same message as the third data packet forwarding control protocol response message, where No restrictions.
  • the intermediate session management network element may send a third data packet forwarding control protocol request message to the source offload user plane network element or the target offload user plane network element, and the third data packet forwarding control protocol request message Including a third data packet detection rule and a third data packet forwarding rule, so that the source offload user plane network element or the target offload user plane network element detects the data packet according to the third data packet detection rule, and forwards the data according to the third data packet forwarding rule packet, which avoids the loss of downlink data packets of the terminal equipment and improves the reliability of data packet transmission.
  • the method may further include: the intermediate session management network element receiving the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information from the session management network element.
  • the session management network element sends the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information to the intermediate session management network element.
  • the intermediate session management network element before the intermediate session management network element sends the third data packet forwarding control protocol request message to the user plane network element, the intermediate session management network element receives the fourth data packet detection rule and the fourth data packet forwarding rule from the session management network element. and the seventh instruction message.
  • the fourth data packet detection rule is a rule for detecting data packets from the source offload user plane network element
  • the fourth data packet forwarding rule is to forward the data packet from the source offload user plane network element to the target access network device the rules of ;
  • the fourth data packet detection rule is a rule for detecting a data packet from a remote user plane network element
  • the fourth data packet forwarding rule is a rule for forwarding a data packet from a remote user plane network element to a target distribution user plane network element
  • the fourth data packet detection rule is a rule for detecting data packets from the source user plane network element
  • the fourth data packet forwarding rule is a rule for forwarding data packets from the source user plane network element to the target distribution user plane network element.
  • the fourth data packet detection rule and the fourth data packet forwarding rule may be included in fourth information, and the fourth information may be N4 information. It can be understood that the fourth information is used to instruct the intermediate session management network element to delete or update the PFCP session with the source offload user plane network element; or, the fourth information is used to instruct the intermediate session management network element to establish a connection with the target offload user plane PFCP session between network elements.
  • the fourth data packet detection rule is a rule for detecting data packets from the remote user plane network element
  • the fourth information is used to instruct the intermediate session management network element to delete or update the PFCP session with the source offload user plane network element
  • the fourth data packet forwarding rule is a rule for forwarding data packets from the remote user plane network element to the target offload user plane network element
  • the fourth information is used to instruct the intermediate session management network element to delete or update the source offload user plane PFCP session between network elements
  • the fourth data packet detection rule is a rule for detecting data packets from the source user plane network element
  • the fourth information is used to instruct the intermediate session management network element to delete or update the user plane network element with the source offload PFCP session between
  • the fourth data packet forwarding rule is a rule for forwarding data packets from the source user plane network element to the target offload user plane network element
  • the fourth information is used to instruct the intermediate session management network element to delete or update the PFCP sessions between source offload user plane network elements
  • the fourth data packet detection rule is a downlink data packet detection rule
  • the fourth data packet forwarding rule is a downlink data packet forwarding rule
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet; the fourth data packet forwarding rule is A rule corresponding to forwarding data packets by a source offload user plane network element or a target offload user plane network element.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element detection data packet; the fourth data packet forwarding rule is the source offload user plane network element The rule corresponding to the meta-forwarding packet.
  • the seventh indication information is used to indicate one or more of the following: the fourth data packet detection rule is the rule corresponding to the target offload user plane network element detection data packet; the fourth data packet forwarding rule is the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the seventh indication information may be a value of the sixth field, and the value of the sixth field may be a value of at least one bit or an enumerated value, which is not limited here.
  • the sixth field can be implemented in any of the following ways:
  • the sixth field may be a newly added field or an original field in the first PDU session update request message.
  • the sixth field may be a newly added field or an original field in the fourth information.
  • the sixth field may be a field in the sixth information element.
  • the sixth information element is the forwarding action information element in the fourth data packet detection rule or the fourth data packet forwarding rule, or an information element with similar definition or function, or an information element with an extended field, which is not limited here.
  • the fourth data packet detection rule is a rule corresponding to the source offload user plane network element detection data packet
  • the fourth data packet forwarding rule is The rule corresponding to the data packet forwarded by the source offload user plane network element.
  • the fourth data packet detection rule is not corresponding to the source offload user plane network element detection packet.
  • the rule and the fourth data packet forwarding rule are not the rules corresponding to the forwarding data packet of the source offload user plane network element, and have no meaning; or, when the value of the sixth field is 0, it is used to indicate one or more of the following: the fourth data packet
  • the detection rule is the rule corresponding to the source offload user plane network element detection data packet
  • the fourth data packet forwarding rule is the source offload user plane network element forwarding data packet corresponding rule
  • the value of the sixth field is 1, which is used to indicate the following One or more items: the fourth data packet detection rule is not the rule corresponding to the detection packet of the source offload user plane network element
  • the fourth data packet forwarding rule is not the corresponding rule corresponding to the source offload user plane network element forwarding data packet, meaningless, here No restrictions.
  • the seventh indication information may be a forwarding tunnel rule indication.
  • the sixth indication information and the seventh indication information may be the same.
  • both the sixth indication information and the seventh indication information are "Y".
  • Table 2 shows the correspondence between data packet detection rules, data packet forwarding rules, and indication information.
  • the fourth data packet detection rule and the fourth data packet forwarding rule described in Table 2 are for the session management network element to instruct the intermediate session management network element to delete or update the PFCP session with the source offload user plane network element Included in the N4 information.
  • DL PDR 258 the identification of the fourth packet detection rule
  • Core source interface
  • N9 source interface type
  • DLFAR There is a corresponding relationship among 258 (identification of the fourth data packet forwarding rule), Access (target interface), N3 (target interface type), and the seventh indication information.
  • the intermediate session management network element can add the tunnel endpoint identifier of the target offload user plane network element and the network address of the target offload user plane network element to the fourth data packet forwarding rule according to the seventh indication information. protocol address.
  • Table 2 Correspondence between packet inspection rules, packet forwarding rules, and indication information
  • the intermediate session management network element can receive the fourth data packet detection rule, the fourth data packet forwarding rule and the seventh indication information from the session management network element, so that the intermediate session management network element can know the following One or more items: the fourth data packet detection rule is the rule corresponding to the source offload user plane network element or the target offload user plane network element detection data packet, the fourth data packet forwarding rule is the source offload user plane network element or the target offload user plane Rules corresponding to network elements forwarding data packets.
  • the third data packet detection rule is that the intermediate session management network element adds the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information
  • the tunnel endpoint identifier and the IP address of the target offloading user plane network element are obtained
  • the third data packet forwarding rule is that the intermediate session management network element adds the tunnel endpoint of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information
  • the identification and the IP address of the target access network device are obtained;
  • the third data packet detection rule is that the intermediate session management network element is in the fourth data packet detection rule according to the seventh instruction information
  • the third data packet forwarding rule is that the intermediate session management network element is in the fourth data packet forwarding rule according to the seventh instruction information It is obtained by adding the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element to get
  • the third data packet forwarding rule also includes The tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that the target offload user plane network element can use the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element Receive and detect data packets, and establish a tunnel with the target access network device according to the tunnel endpoint identifier of the target access network device and the IP address of the target access network device, so that the data packets can be transmitted through the tunnel, avoiding the diversion of the target user plane The loss of data packets between network elements and target access network equipment.
  • the third data packet forwarding rule also includes the target offload user plane network element The tunnel endpoint identifier of the source offload user plane network element and the IP address of the target offload user plane network element, so that the source offload user plane network element can receive and detect data according to the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element packet, according to the tunnel endpoint identifier of the target offload user plane NE, the IP address of the target offload user plane NE, and the target offload user plane NE to establish a tunnel, so that the data packet can be transmitted through the tunnel, avoiding the downlink data of the terminal equipment Packet loss.
  • FIG. 6A is a schematic flowchart of another message transmission provided by the embodiment of the present application. As shown in Figure 6A, the method includes but is not limited to the following steps:
  • the intermediate session management network element sends a first PFCP session establishment request message to the target user plane network element, and the PFCP session establishment request message is used to notify the target user plane network element to establish a PFCP session of the terminal device.
  • the target user plane network element receives the first PFCP session establishment request message from the intermediate session management network element.
  • the first PFCP session establishment request message in step 601 includes a first uplink data packet detection rule and a first uplink data packet forwarding rule, a first downlink data packet detection rule and a first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for the target user plane network element to establish an uplink forwarding channel for all service data packets
  • the first downlink data packet detection rule and the first downlink data packet forwarding rule are used for Establish a downlink forwarding channel for all service data packets at the target user plane network element. It can be understood that the uplink service data packet is received by the target user plane network element and forwarded to the data network, and the downlink service data packet is received by the target user plane network element and forwarded to the target offloading user plane network element.
  • the target user plane network element replies a first PFCP session establishment response message (PFCP session establishment response) to the intermediate session management network element, and the first PFCP session establishment response message indicates that the first PFCP session is successfully established.
  • PFCP session establishment response PFCP session establishment response
  • the intermediate session management network element receives the first PFCP session establishment response message from the target user plane network element.
  • the PFCP session establishment response message in step 602 includes the service data packet forwarding information allocated by the target user plane network element, and the service data packet forwarding information includes the tunnel endpoint identifier of the target user plane network element and the IP address of the target user plane network element , the tunnel endpoint identifier of the target user plane network element and the IP address of the target user plane network element are used by the intermediate session management network element to instruct the target offloading user plane network element to establish a forwarding channel for the uplink service data packet.
  • the intermediate session management network element decides and establishes the forwarding tunnel of the uplink or downlink service data packets, which is used to ensure the process of splitting the user plane network element and changing the user plane network element at the same time.
  • Continuity of uplink or downlink business data packets For example, the intermediate session management network element determines whether to establish a forwarding tunnel for uplink or downlink service data packets according to whether an N3 user plane tunnel is established between the source offload user plane network element and the source access network device. That is, if an N3 user plane tunnel is established between the source offload user plane network element and the source access network device, the intermediate session management network element determines that a forwarding tunnel for uplink or downlink service data packets needs to be established.
  • the intermediate session management network element sends a second PFCP session establishment request message to the target offload user plane network element, and the PFCP session establishment request message is used to notify the target offload user plane network element to establish a PFCP session of the terminal device.
  • the target offload user plane network element receives the second PFCP session establishment request message from the intermediate session management network element.
  • the second PFCP session establishment request message in step 603 includes the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for target offload user plane network elements to establish uplink forwarding channels for all service data packets, the first downlink data packet detection rule and the first downlink data packet forwarding rule It is used for target offloading user plane network elements to establish downlink forwarding channels for all service data packets.
  • the uplink service data packet is sent by the target access network device to the target offload user plane network element, and then forwarded by the target offload user plane network element to the remote user plane network element, and the downlink service data packet is sent by the remote user plane network element.
  • the target offload user plane network element forwards it to the target access network device.
  • the second PFCP session establishment request message in step 603 also includes a second downlink data packet detection rule and a second downlink data packet forwarding rule, the second downlink data packet detection rule and the second downlink data packet forwarding rule are used for target distribution
  • the user plane network element establishes a forwarding channel for the downlink service data packet, so as to ensure the continuity of the downlink service data packet in the process of offloading the user plane network element and simultaneously changing the user plane network element.
  • the downlink service data packet is sent by the source offload user plane network element to the target offload user plane network element, and then forwarded by the target offload user plane network element to the target access network device.
  • the second PFCP session establishment request message in step 603 is the same message as the third PFCP request message sent by the intermediate session management network element to the target offload user plane network element in step 501 in FIG. 5 , and the second downlink data in step 603
  • the packet detection rule is the same as the third packet detection rule sent by the intermediate session management network element to the target offloading user plane network element in step 501 in Figure 5, and the second downlink data packet forwarding rule is the same as that in step 501 in Figure 5.
  • the third data packet sent by the target offloading user plane network element has the same forwarding rule.
  • the target offload user plane network element replies a second PFCP session establishment response message to the intermediate session management network element, and the second PFCP session establishment response message is used to indicate that the second PFCP session is successfully established.
  • the intermediate session management network element receives the second PFCP session establishment response message from the target offload user plane network element.
  • the second PFCP session establishment response message in step 604 includes the forwarding information of the first service data packet, the forwarding information of the second service data packet and the forwarding information of the third service data packet allocated by the target offloading user plane network element.
  • the forwarding information of the first service data packet, the forwarding information of the second service data packet and the forwarding information of the third service data packet all include the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element.
  • the first service data packet forwarding information is used by the intermediate session management network element to instruct the target access network device to establish a forwarding channel for the uplink service data packet
  • the second service data packet forwarding information is used by the intermediate session management network element to instruct the target user plane network element or
  • the remote user plane network element establishes the forwarding channel of the downlink service data packet
  • the third service data packet forwarding information is used for the intermediate session management network element to instruct the source splitting user plane network element to establish the downlink service data packet to ensure the continuity of the downlink service data packet forwarding channel.
  • the intermediate session management network element sends a first PFCP session update request message to the source offload user plane network element, and the first PFCP session update request message is used to notify the source offload user plane network element to update the third PFCP session of the terminal device.
  • the source offload user plane network element receives the first PFCP session update request message from the intermediate session management network element.
  • the first PFCP session update request message in step 605 includes the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule, the first The uplink data packet detection rule and the first uplink data packet forwarding rule are used for the source offload user plane network element to establish an uplink forwarding channel for the service data packet offloaded from the source user plane network element, the first downlink data packet detection rule and the first downlink data packet
  • the upstream data packet forwarding rules are used to source offload user plane network elements to establish downlink forwarding channels for all service data packets, so as to ensure the continuity of uplink or downlink service data packets in the process of simultaneous change of offload user plane network elements and user plane network elements sex.
  • the uplink service data packet is sent from the target offload user plane network element to the source offload user plane network element, and then forwarded by the source offload user plane network element to the source user plane network element.
  • the downlink service data packet is sent from the remote user plane network element to the source distribution user plane network element or from the source user plane network element to the source distribution user plane network element, and then forwarded by the source distribution user plane network element to the target distribution user network element.
  • the first PFCP session update request message in step 605 is the same message as the first packet forwarding control protocol request message sent by the intermediate session management network element to the source offload user plane network element in step 405 in FIG.
  • the first uplink data packet detection rule is the same as the first data packet detection rule sent by the intermediate session management network element to the source offload user plane network element in step 405 in Figure 4, and the first uplink data packet forwarding rule is the same as the step 405 intermediate session
  • the forwarding rule of the first data packet sent by the management network element to the source offload user plane network element is the same.
  • the first PFCP session update request message in step 605 is the same message as the third packet forwarding control protocol request message sent by the intermediate session management network element to the source offload user plane network element in step 501 in FIG.
  • the data packet detection rule is the same as the third data packet detection rule sent by the intermediate session management network element to the source offload user plane network element in step 501 in FIG. 5, and the first downlink data packet forwarding rule is the same as that in FIG.
  • the forwarding rule of the third data packet sent by the element to the source offload user plane network element is the same.
  • the source offload user plane network element replies the first PFCP session update response message to the intermediate session management network element, and the first PFCP session update response message indicates that the third PFCP session is successfully updated.
  • the intermediate session management network element receives the first PFCP session update response message from the source offload user plane network element.
  • the first PFCP session update response message in step 606 includes the service data packet forwarding information assigned by the source offload user plane network element, and the service data packet forwarding information includes the tunnel endpoint identifier of the source offload user plane network element and the source offload user plane network element.
  • the IP address of the element is used by the intermediate session management network element to instruct the target offload user plane network element to establish a forwarding channel for the uplink service data packet to ensure the continuity of the uplink service data packet.
  • step 606 the downlink service data packet forwarding path:
  • this solution may also include but not limited to the following steps 607-616.
  • FIG. 6B is a schematic flowchart of another message transmission method provided by the embodiment of this application.
  • the intermediate session management network element sends a first PDU session update request (Nsmf_PDUSession_Update request) to the session management network element, and the first PDU session update request message includes the first indication information and the first instruction information allocated by the target offload user plane network element in step 604. 2. Service data packet forwarding information.
  • the session management network element receives the first PDU session update request from the intermediate session management network element.
  • the session management network element replies the first PDU session update response message (Nsmf_PDUSession_Update response) to the intermediate session management network element.
  • the first PDU session update response message contains the first N4 information, the second N4 information, the third N4 information and the first N4 information. Four N4 information.
  • the intermediate session management network element receives the first PDU session update response message from the session management network element.
  • the first N4 information is used to instruct the intermediate session management network element to establish a PFCP session between the intermediate session management network element and the target offload user plane network element, and the first N4 information includes the third uplink data packet detection rule, the third uplink data packet detection rule, and the third uplink data packet detection rule.
  • the third uplink data packet detection rule and the third uplink data packet forwarding rule are used to instruct the target offload user plane network element to establish an uplink forwarding channel for the service data packets offloaded from the target user plane network element, and the third downlink data packet detection rule and the first The three downlink data packet forwarding rules are used to instruct the target offload user plane network element to establish a downlink forwarding channel for the service data packets offloaded from the target user plane network element.
  • the uplink service data packet is sent from the target access network device to the target offload user plane network element, and then forwarded to the target user plane network element by the target offload user plane network element, and the downlink service data packet is sent to the target offload user plane network element by the target user plane network element After the user plane network element, the target offloads the user plane network element and forwards it to the target access network device.
  • the first N4 information includes the uplink data packet detection rule and the uplink data packet forwarding rule corresponding to the service, or, the first The N4 information includes a downlink data packet detection rule and a downlink data packet forwarding rule corresponding to the service.
  • the second N4 information is used to instruct the intermediate session management network element to establish a PFCP session between the intermediate session management network element and the target user plane network element
  • the second N4 information includes the second uplink data packet detection rule, the second uplink data packet forwarding rule, the second downlink data packet detection rule and the second downlink data packet forwarding rule.
  • the second uplink data packet detection rule and the second uplink data packet forwarding rule are used to instruct the target user plane network element to establish an uplink forwarding channel for service data packets offloaded from the target user plane network element
  • the second downlink data packet detection rule and the second The downlink data packet forwarding rule is used to instruct the target user plane network element to establish a downlink forwarding channel for the service data packets offloaded from the target user plane network element.
  • the uplink service data packet is sent to the target user plane network element by the target offloading user plane network element, and then forwarded to the data network by the target user plane network element, and the downlink service data packet is sent to the target user plane network element by the data network After that, it is forwarded by the target user plane network element to the target offloading user plane network element.
  • the third N4 information is used to instruct the intermediate session management network element to delete the PFCP session between the intermediate session management network element and the source offload user plane network element.
  • the fourth N4 information is used to instruct the intermediate session management network element to delete the PFCP session between the intermediate session management network element and the source user plane network element.
  • the change of the local user plane network element may lead to the switching of the application network element, and the session management network element can notify the source application network element of the access point identifier (DN Access Identifier, DNAI) of the target user plane network element, so that the source application network element
  • the handover of the application network element is triggered according to the access point identifier. If the application network element subscribes to the event of the session management network element, it indicates that the confirmation of the application network element is required, that is, the application network element performs the handover and sends a positive confirmation to the session management network element before sending the uplink data packet to the new application network element .
  • the target application network element when the source application network element switches to the target application network element, the target application network element can send a forward confirmation to the session management network element.
  • the target user plane network element can send the uplink data packet Send it to the target application network element. Therefore, in order to realize this process, the first PDU session update response message in step 608 also includes the second indication information.
  • the second indication information reference may be made to the relevant description of step 402 in FIG. 4 , and details are not repeated here.
  • the second indication information may be implemented through any of the following situations:
  • the session management network element may instruct the target user plane network element to cache uplink data packets through a bit or enumeration in the first PDU session update response message in step 608, such as passing a bit to indicate, where the bit is set to 1 to indicate that the target user plane network element caches the uplink data packet, and the bit is set to 0 to indicate that the target user plane network element does not need to cache the uplink data packet or forward the uplink data packet or has no special meaning; or If this bit is set to 0, it means that the target user plane network element caches the uplink data packet; when this bit is set to 1, it means that the target user plane network element does not need to cache the uplink data packet or forward the uplink data packet or has no special meaning; or a new parameter or an existing Indicated by an enumeration in the parameter, a specific enumeration value indicates that the target user plane network element caches the uplink data packet;
  • case 1.2 the session management network element can also indicate the target user plane network element to buffer the uplink data packet through a bit or an enumeration in the second N4 information.
  • the specific indication method can refer to the indication method of the above case 1.1.
  • the session management network element may set the cache bit in the forwarding action information element contained in the second uplink data packet forwarding rule contained in the second N4 information to 1 to instruct the target user plane network element to cache the uplink data packet .
  • the session management network element sends a second PFCP session update request message to the remote user plane network element, and the second PFCP session update request message is used to notify the remote user plane network element to update the PFCP session of the terminal device.
  • the remote user plane network element receives the second PFCP session update request message from the session management network element.
  • the second PFCP session update request message in step 609 includes the second service data packet forwarding information allocated by the target offload user plane network element in step 607, and after the remote user plane network element receives the downlink service data packet from the data network , sending the downlink service data packet to the target offload user plane network element according to the second service data packet forwarding information allocated by the target offload user plane network element.
  • the remote user plane network element replies a second PFCP session update response message to the session management network element, and the second PFCP session update response message indicates that the fourth PFCP session is successfully updated.
  • the session management network element receives the PFCP session update response message from the remote user plane network element.
  • step 610 the downlink service data packet forwarding path:
  • the intermediate session management network element sends a third PFCP session update request message to the target offload user plane network element, and the third PFCP session update request message is used to notify the target offload user plane network element to update the PFCP session of the terminal device.
  • the target offload user plane network element receives the third PFCP session update request message from the intermediate session management network element.
  • the third PFCP session update request message in step 611 includes the third uplink data packet detection rule, the third uplink data packet forwarding rule, the third downlink data packet detection rule and the third uplink data packet detection rule included in the first N4 information in step 608. Downlink data packet forwarding rules.
  • the third PFCP session update request message in step 611 also includes the second uplink data packet detection rule and the second uplink data packet forwarding rule, the second uplink data packet detection rule and the second uplink data packet forwarding rule are used for target distribution
  • the user plane network element establishes an uplink forwarding channel for the service data packet offloaded from the source user plane network element, so as to ensure the continuity of the uplink service data packet in the process of the offloaded user plane network element and the simultaneous change of the user plane network element.
  • the uplink service data packet is sent by the target access network device to the target offload user plane network element, and then forwarded by the target offload user plane network element to the source offload user plane network element.
  • the third PFCP session update request message in step 611 is the same message as the first data packet forwarding control protocol request message sent by the intermediate session management network element to the target offload user plane network element in step 405 in FIG.
  • the second uplink data packet detection rule is the same as the first data packet detection rule sent by the intermediate session management network element to the target offload user plane network element in step 405 in Figure 4, and the second uplink data packet forwarding rule is the same as the step 405 intermediate session
  • the forwarding rule of the first data packet sent by the management network element to the target offload user plane network element is the same.
  • the target offload user plane network element replies a third PFCP session update response message to the intermediate session management network element, and the third PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the third PFCP session update response message from the target offload user plane network element.
  • the intermediate session management network element sends a fourth PFCP session update request message to the target user plane network element, and the fourth PFCP session update request message is used to notify the target user plane network element to update the PFCP session of the terminal device.
  • the target user plane network element receives the fourth PFCP session update request message from the intermediate session management network element.
  • the fourth PFCP session update request message in step 613 includes the second uplink data packet detection rule, the second uplink data packet forwarding rule, the second downlink data packet detection rule, and the second N4 information in step 608. Downlink data packet forwarding rules.
  • the fourth PFCP session update request message in step 613 also includes third indication information.
  • third indication information reference may be made to the relevant description of step 403 in FIG. 4 , and details are not repeated here.
  • the intermediate session management network element forwards the third indication information to the target user plane network element; for case 1.1 in step 608, the intermediate session management network element according to the received The second indication information is to set the buffer bit in the forwarding action information element included in the second uplink data packet forwarding rule sent to the target user plane network element to 1 to instruct the target user plane network element to cache the uplink data packet.
  • the target user plane network element replies a fourth PFCP session update response message to the intermediate session management network element, and the fourth PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the fourth PFCP session update response message from the target user plane network element.
  • step 614 the downlink service data packet forwarding path:
  • the intermediate session management network element sends a PDU session resource update request message to the target access network device, and the PDU session resource update request message includes the forwarding information of the first service data packet in step 604.
  • the target access network device receives a PDU session resource update request message from the intermediate session management network element.
  • the target access network device replies a PDU session resource update response message to the intermediate session management network element, and the PDU session resource update response message indicates that the PDU session resource update is successful.
  • the intermediate session management network element receives the PDU session resource update response message from the target access network device.
  • step 616 the uplink service data packet forwarding path:
  • this solution may also include but not limited to the following steps 617-624.
  • FIG. 6C is a schematic flowchart of another message transmission method provided by the embodiment of this application.
  • the session management network element waits for the confirmation message from the target application network element.
  • the session management network element After the session management network element receives the confirmation message from the target application network element, the session management network element sends the second PDU session update message (Nsmf_PDUSession_Update request) to the intermediate session management network element, and the second PDU session update message contains the fourth indication information .
  • the target application network element sends a confirmation message to the session management network element.
  • the fourth indication information may be implemented through any of the following situations:
  • the session management network element can instruct the target user plane network element to forward the uplink data packet through a bit or an enumeration in the message, such as through a bit in a new parameter or an original parameter, where the bit is set to If it is 1, it means that the target user plane network element forwards the uplink data packet; if this bit is set to 0, it means that the target user plane network element does not need to forward the uplink data packet or cache the uplink data packet or has no special meaning; or if this bit is set to 0, it means that the target user plane network element The network element forwards the uplink data packet, and this bit is set to 1 to indicate that the target user plane network element does not need to forward the uplink data packet or buffer the uplink data packet or has no special meaning; or the new parameter or the original parameter is indicated by enumeration, A specific enumeration value indicates that the target user plane network element forwards the uplink data packet.
  • the session management network element may also include fifth N4 information in the message, and the fifth N4 information is used to indicate to update the PFCP session between the intermediate session management network element and the target user plane network element, and is passed in the fifth N4 information
  • a bit or an enumeration indicates that the target user plane network element forwards the uplink data packet, and the specific indication manner may refer to the indication manner in the above-mentioned case 2.1, and details are not described here.
  • the session management network element may include the uplink data packet forwarding rule in the fifth N4 information, and set the forwarding bit in the forwarding action information element contained in the uplink data packet forwarding rule to 1 to indicate forwarding the uplink data packet .
  • the uplink data packet forwarding rule here is the second uplink data packet forwarding rule in the second N4 information in step 608 .
  • the intermediate session management network element replies the second PDU session update response message to the session management network element (Nsmf_PDUSession_Update response), and the second PDU session update response message indicates that the second PDU session update is successful.
  • the session management network element receives the second PDU session update response message from the intermediate session management network element.
  • the intermediate session management network element sends a fifth PFCP session update request message to the target user plane network element, and the user of the fifth PFCP session update request message notifies the target user plane network element to update the PFCP session of the terminal device.
  • the target user plane network element receives the fifth PFCP session update request message from the intermediate session management network element.
  • the fifth PFCP session update request message in step 620 includes fifth indication information, and for the fifth indication information, reference may be made to the related description of step 405 in FIG. 4 , and details are not repeated here.
  • the intermediate session management network element forwards the fourth instruction information to the target user plane network element; for situation 2.1 in step 618, the intermediate session management network element forwards the fourth instruction information according to the fourth instruction information , setting the forwarding bit in the forwarding action information element contained in the second uplink data packet forwarding rule sent to the target user plane network element to 1 to indicate forwarding the uplink data packet.
  • the intermediate session management network element sends the fifth indication information to the target user plane network element according to the fourth indication information.
  • the target user plane network element replies with a fifth PFCP session update response message, and the fifth PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the fifth PFCP session update response message from the target user plane network element.
  • step 621 the uplink service data packet forwarding path:
  • the source offload user plane network element When the source offload user plane network element does not forward the service data packet within the preset time, it sends a PFCP session report to the intermediate session management network element, and the PFCP session report is used to notify the intermediate session management network element of this event, that is, PFCP The session report is used to notify the source offloading user plane network element that the service data packet has not been forwarded within a preset time.
  • the intermediate session management network element receives the PFCP session report from the source offload user plane network element.
  • the intermediate session management network element initiates deletion of the originating session according to the PFCP session report, and sends a PFCP session deletion message to the source user plane network element.
  • the intermediate session management network element sends a PFCP session deletion message to the source distribution user plane network element.
  • the target user plane network element since the target user plane network element does not forward the uplink data packet before the target application network element completes the handover, but buffers the uplink data packet before the target application network element completes the handover, the uplink data packet is not forwarded Forwarding, avoiding the loss of uplink data packets.
  • the target user plane network element since the target user plane network element forwards the uplink data packet after the target application network element completes the handover, the uplink data packet can be forwarded to the target application network element, which improves the reliability of data packet transmission. At the same time, the loss of uplink and downlink data packets of the terminal equipment is avoided, and the continuity and reliability of data packet transmission are improved.
  • FIG. 7A is a schematic flowchart of another message transmission method provided in an embodiment of the present application. As shown in Figure 7A, the method includes but is not limited to the following steps:
  • the intermediate session management network element sends a first PFCP session establishment request message to the target user plane network element, and the first PFCP session establishment request message is used to notify the target user plane network element to establish a PFCP session of the terminal device.
  • the target user plane network element receives the first PFCP session establishment request message from the intermediate session management network element.
  • the first PFCP session establishment request message in step 701 includes the first uplink data packet detection rule and the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for the target user plane network element to establish an uplink forwarding channel for all service data packets
  • the first downlink data packet detection rule and the first downlink data packet forwarding rule are used for Establish a downlink forwarding channel for all service data packets at the target user plane network element. It can be understood that the uplink service data packet is received by the target user plane network element and forwarded to the data network, and the downlink service data packet is received by the target user plane network element and forwarded to the target offloading user plane network element.
  • the target user plane network element replies the first PFCP session establishment response message to the intermediate session management network element, and the first PFCP session establishment response message indicates that the PFCP session is established successfully.
  • the intermediate session management network element receives the first PFCP session establishment response message from the target user plane network element.
  • the PFCP session establishment response message in step 702 includes the service data packet forwarding information assigned by the target user plane network element, and the service data packet forwarding information includes the tunnel endpoint identifier of the target user plane network element and the IP address of the target user plane network element , the tunnel endpoint identifier of the target user plane network element and the IP address of the target user plane network element are used by the intermediate session management network element to instruct the target access network device to establish a forwarding channel for the uplink service data packet.
  • the intermediate session management network element sends a second PFCP session establishment request message to the target offload user plane network element, and the second PFCP session establishment request message is used to notify the target offload user plane network element to establish a PFCP session of the terminal device.
  • the target offload user plane network element receives the second PFCP session establishment request message from the intermediate session management network element.
  • the second PFCP session establishment request message in step 703 includes the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for target offload user plane network elements to establish uplink forwarding channels for all service data packets, the first downlink data packet detection rule and the first downlink data packet forwarding rule It is used for target offloading user plane network elements to establish downlink forwarding channels for all service data packets.
  • the uplink service data packet is sent by the target access network device to the target offload user plane network element, and then forwarded by the target offload user plane network element to the remote user plane network element, and the downlink service data packet is sent by the remote user plane network element.
  • the target offload user plane network element forwards it to the target access network device.
  • the target offload user plane network element replies a second PFCP session establishment response message to the intermediate session management network element, and the second PFCP session establishment response message is used to indicate that the PFCP session is established successfully.
  • the intermediate session management network element receives the second PFCP session establishment response message from the target offload user plane network element.
  • the second PFCP session establishment response message in step 704 includes the forwarding information of the first service data packet, the forwarding information of the second service data packet and the forwarding information of the third service data packet allocated by the target offloading user plane network element.
  • the forwarding information of the first service data packet, the forwarding information of the second service data packet and the forwarding information of the third service data packet all include the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element.
  • the first service data packet forwarding information is used by the intermediate session management network element to instruct the target access network device to establish a forwarding channel for the uplink service data packet
  • the second service data packet forwarding information is used by the intermediate session management network element to instruct the target user plane network element/
  • the remote user plane network element establishes the forwarding channel of the downlink service data packet
  • the third service data packet forwarding information is used for the intermediate session management network element to instruct the source splitting user plane network element to establish the downlink service data packet to ensure the continuity of the downlink service data packet forwarding channel.
  • the intermediate session management network element sends a first PDU session update request (Nsmf_PDUSession_Update request) to the session management network element, and the first PDU session update request message includes the first indication information and the first instruction information allocated by the target offload user plane network element in step 704. 2. Service data packet forwarding information.
  • the session management network element receives the first PDU session update request from the intermediate session management network element.
  • the session management network element determines and establishes the forwarding tunnel of the uplink or downlink service data packets, which is used to ensure the uplink or downlink service in the process of shunting the user plane network element and changing the user plane network element at the same time. Continuity of packets. It can be understood that the session management network element may establish a forwarding tunnel for uplink or downlink service data packets for all sessions, or establish a forwarding tunnel for uplink or downlink service data packets for a specific session.
  • the session management network element replies the first PDU session update response message (Nsmf_PDUSession_Updateresponse) to the intermediate session management network element.
  • the first PDU session update response message contains the first N4 information, the second N4 information, the third N4 information and the fourth N4 information. N4 information.
  • the intermediate session management network element receives the first PDU session update response message from the session management network element.
  • the first N4 information is used to instruct the intermediate session management network element to establish a PFCP session between the intermediate session management network element and the target offload user plane network element, and the first N4 information includes the second uplink data packet detection rule, the second uplink data packet A forwarding rule, a second downlink data packet detection rule and a second downlink data packet forwarding rule.
  • the second uplink data packet detection rule and the second uplink data packet forwarding rule are used to instruct the target offload user plane network element to establish an uplink forwarding channel for the service data packets offloaded from the target user plane network element, the second downlink data packet detection rule and the first The second downlink data packet forwarding rule is used to instruct the target offloading user plane network element to establish a downlink forwarding channel for the service data packets offloaded from the target user plane network element.
  • the uplink service data packet is sent from the target access network device to the target offload user plane network element, and then forwarded to the target user plane network element by the target offload user plane network element, and the downlink service data packet is sent to the target offload user plane network element by the target user plane network element After the user plane network element, the target offloads the user plane network element and forwards it to the target access network device.
  • the first N4 information includes the uplink data packet detection rule and the uplink data packet forwarding rule corresponding to the service, or, the first The N4 information includes a downlink data packet detection rule and a downlink data packet forwarding rule corresponding to the service.
  • the first N4 information also includes a third uplink data packet detection rule, a third uplink data packet forwarding rule, a third downlink data packet detection rule, and a third downlink data packet forwarding rule.
  • the third uplink data packet detection rule and the third uplink data packet forwarding rule are used for the target offload user plane network element to establish the uplink forwarding channel of the service data packet offloaded from the source user plane network element, the third downlink data packet detection rule and the third The downlink data packet forwarding rule is used to establish the downlink forwarding channel of all service data packets for the target offload user plane network element, so as to ensure the continuity of the uplink or downlink service data packets in the process of simultaneous change of the offload user plane network element and the user plane network element sex.
  • the uplink service data packet is sent by the target access network device to the target offload user plane network element, and then forwarded by the target offload user plane network element to the source offload user plane network element.
  • the downlink service data packet is sent from the source offload user plane network element to the target offload user plane network element, and then forwarded by the target offload user plane network element to the target access network device.
  • the third uplink data packet detection rule included in the first N4 information is the same as the second data packet detection rule received by the intermediate session management network element from the session management network element in step 405 in FIG.
  • the third uplink data packet forwarding rule is the same as the second data packet forwarding rule received by the intermediate session management network element from the session management network element in step 405 in FIG. 4 .
  • the third downlink data packet detection rule included in the first N4 information is the same as the fourth data packet detection rule received by the intermediate session management network element from the session management network element in step 501 in Figure 5, and the third downlink data packet detection rule included in the first N4 information
  • the data packet forwarding rule is the same as the fourth data packet forwarding rule received by the intermediate session management network element from the session management network element in step 501 in FIG. 5 .
  • the second data packet detection rule is the rule corresponding to the detection data packet of the target offload user plane network element
  • the second data packet forwarding rule is the corresponding rule of the target offload user plane network element forwarding data packet
  • the fourth data packet detection rule is the target The offloading user plane network element detects a rule corresponding to the data packet
  • the fourth data packet forwarding rule is a rule corresponding to the target offloading user plane network element forwarding the data packet.
  • the first N4 information also includes a forwarding tunnel rule indication, which is used to indicate that the above-mentioned third uplink data packet detection rule and the third uplink data packet forwarding rule are to ensure that the user plane network element and the user plane network element are changed at the same time.
  • the rules corresponding to the data packet forwarding tunnels that need to be established for the continuity of the uplink service data packets, the third downlink data packet detection rule and the third downlink data packet forwarding rule are to ensure The rules corresponding to the data packet forwarding tunnels that need to be established for the continuity of downlink service data packets in the changed process.
  • the forwarding tunnel rule indication included in the first N4 information includes the sixth indication information and the seventh indication information.
  • the forwarding tunnel rule indication contained in the first N4 information may be implemented through any of the following situations:
  • the session management network element can indicate forwarding tunnel rules through a bit or an enumeration in the first PDU session update response message, such as indicating through a bit in a new parameter or an original parameter, where the bit is set to 1 indicates a forwarding tunnel rule, and this bit is set to 0 to indicate that it is not a forwarding tunnel rule or has no special meaning; or this bit is set to 0 to indicate a forwarding tunnel rule, and this bit is set to 1 to indicate that it is not a forwarding tunnel rule or has no special meaning;
  • the parameter or the original parameter is indicated by enumeration, and a specific enumeration value indicates the forwarding tunnel rule.
  • case 3.2 The session management network element can also pass in the first N4 information, the third uplink data packet detection rule, the third uplink data packet forwarding rule, the third downlink data packet detection rule or the third downlink data packet forwarding rule A bit or an enumeration indicates the forwarding tunnel rule, and the specific indication manner of the forwarding tunnel rule indication can refer to the case 3.1, which will not be repeated here.
  • the second N4 information is used to instruct the intermediate session management network element to establish a PFCP session between the intermediate session management network element and the target user plane network element
  • the second N4 information includes the second uplink data packet detection rule, the second uplink data packet forwarding rule, the second downlink data packet detection rule and the second downlink data packet forwarding rule.
  • the second uplink data packet detection rule and the second uplink data packet forwarding rule are used to instruct the target user plane network element to establish an uplink forwarding channel for service data packets offloaded from the target user plane network element
  • the second downlink data packet detection rule and the second The downlink data packet forwarding rule is used to instruct the target user plane network element to establish a downlink forwarding channel for the service data packets offloaded from the target user plane network element.
  • the uplink service data packet is sent to the target user plane network element by the target offloading user plane network element, and then forwarded to the data network by the target user plane network element, and the downlink service data packet is sent to the target user plane network element by the data network After that, it is forwarded by the target user plane network element to the target offloading user plane network element.
  • the third N4 information is used to instruct the intermediate session management network element to delete the PFCP session between the intermediate session management network element and the source offload user plane network element;
  • the third N4 information is used to indicate to update the PFCP session between the intermediate session management network element and the source offload user plane network element, and the third N4 information includes the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first A downlink data packet detection rule and a first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for the source offload user plane network element to establish an uplink forwarding channel for the service data packet offloaded from the source user plane network element, and the first downlink data packet detection rule and the first downlink data packet detection rule
  • the downlink data packet forwarding rules are used to source offload user plane network elements to establish downlink forwarding channels for all service data packets, thereby ensuring uplink or downlink service data packets in the process of shunting user plane network elements and user plane network elements changing at the same time continuity. It can be understood that the first uplink data packet detection rule included in the third N4 information is the same as the second data packet detection rule received by the intermediate session management network element from the session management network element in step 405 in FIG.
  • the third N4 information includes The first uplink data packet forwarding rule is the same as the second data packet forwarding rule received by the intermediate session management network element from the session management network element in step 405 in FIG. 4 .
  • the first downlink data packet detection rule included in the third N4 information is the same as the fourth data packet detection rule received by the intermediate session management network element from the session management network element in step 501 in FIG. 5 , and the first downlink data packet detection rule included in the third N4 information
  • the downlink data packet forwarding rule is the same as the fourth data packet forwarding rule received by the intermediate session management network element from the session management network element in step 501 in FIG. 5 .
  • the second data packet detection rule is the rule corresponding to the source offload user plane network element detection data packet
  • the second data packet forwarding rule is the source offload user plane network element forwarding data packet corresponding rule
  • the fourth data packet detection rule is the source The offloading user plane network element detects a rule corresponding to the data packet
  • the fourth data packet forwarding rule is a rule corresponding to the source offloading user plane network element forwarding data packet.
  • the third N4 information also includes a forwarding tunnel rule indication
  • the forwarding tunnel rule indication is used to indicate that the above-mentioned first uplink data packet detection rule and the first uplink data packet forwarding rule are to ensure that the user plane network element and the user plane network element simultaneously
  • the rules corresponding to the data packet forwarding tunnel that needs to be established for the continuity of the uplink service data packets in the changed process, the first downlink data packet detection rule and the first downlink data packet forwarding rule are to ensure The rules corresponding to the data packet forwarding tunnels that need to be established for the continuity of the downlink service data packets in the process of simultaneous change of the user plane network elements.
  • the specific indication manner of the forwarding tunnel rule indication refer to the indication manner of the forwarding tunnel rule indication in the first N4 information, which will not be repeated here.
  • the fourth N4 information is used to instruct the intermediate session management network element to delete the PFCP session between the intermediate session management network element and the source user plane network element.
  • the change of the local user plane NE may lead to switching of the application NE, and the session management NE can notify the source application NE of the access point identifier of the target user plane NE, so that the source application NE can trigger the application according to the access point identifier.
  • Network element switching If the application network element subscribes to the event of the session management network element, it indicates that the confirmation of the application network element is required, that is, the application network element performs the handover and sends a positive confirmation to the session management network element before sending the uplink data packet to the new application network element . In other words, when the source application network element switches to the target application network element, the target application network element can send a forward confirmation to the session management network element.
  • the target user plane network element can send the uplink data packet Send it to the target application network element. Therefore, in order to realize this process, the first PDU session update response message in step 706 also includes the second indication information.
  • the second indication information reference may be made to the relevant description of step 402 in FIG. 4 , and details are not repeated here.
  • the second indication information may be implemented through any of the following situations:
  • the session management network element may instruct the target user plane network element to cache uplink data packets through a bit or enumeration in the first PDU session update response message in step 706, such as passing a bit to indicate, where the bit is set to 1 to indicate that the target user plane network element caches the uplink data packet, and the bit is set to 0 to indicate that the target user plane network element does not need to cache the uplink data packet or forward the uplink data packet or has no special meaning; or If this bit is set to 0, it means that the target user plane network element caches the uplink data packet; when this bit is set to 1, it means that the target user plane network element does not need to cache the uplink data packet or forward the uplink data packet or has no special meaning; or a new parameter or an existing Indicated by an enumeration in the parameter, a specific enumeration value indicates that the target user plane network element caches the uplink data packet;
  • case 4.2 the session management network element may also indicate the target user plane network element to buffer the uplink data packet through a bit or an enumeration in the second N4 information.
  • the specific indication method may refer to the indication method of the above case 1.1. without elaboration;
  • the session management network element may set the cache bit in the forwarding action information element contained in the second uplink data packet forwarding rule contained in the second N4 information to 1 to instruct the target user plane network element to cache the uplink data packet .
  • this solution may also include but not limited to the following steps 707-716.
  • FIG. 7B is a schematic flowchart of another message transmission method provided by the embodiment of this application.
  • the intermediate session management network element sends a first PFCP session update request message to the source offload user plane network element, and the first PFCP session update request message is used to notify the source offload user plane network element to update the PFCP session of the terminal device.
  • the source offload user plane network element receives the first PFCP session update request message from the intermediate session management network element.
  • the first PFCP session update request message in step 707 includes the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule.
  • the first uplink data packet detection rule and the first uplink data packet forwarding rule are used for the source offload user plane network element to establish an uplink forwarding channel for the service data packet offloaded from the source user plane network element, the first downlink data packet detection rule and the first downlink data packet detection rule
  • the downlink data packet forwarding rule is used to source offload user plane network elements to establish downlink forwarding channels for all service data packets, so as to ensure the uplink or downlink service data packets in the process of offloading user plane network elements and user plane network elements changing at the same time continuity.
  • the uplink service data packet is sent from the target offload user plane network element to the source offload user plane network element, and then forwarded by the source offload user plane network element to the source user plane network element.
  • the downlink service data packet is sent from the remote user plane network element to the source distribution user plane network element or from the source user plane network element to the source distribution user plane network element, and then forwarded by the source distribution user plane network element to the target distribution user network element.
  • the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule in step 707 are intermediate session management network elements Determine the first uplink data packet detection rule and the first uplink data packet forwarding rule according to the forwarding tunnel rule indication in the third N4 information of step 706, the first downlink data packet detection rule and the first downlink data packet forwarding rule are to ensure The continuity of the uplink or downlink service data packets in the process of diverting the user plane function and changing the user plane function at the same time requires the establishment of a data packet forwarding tunnel, and the first uplink data packet detection rule in step 707 is an intermediate session management network element
  • the first uplink data packet detection rule in the third N4 information in step 706 is obtained by adding the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, and the first uplink data packet in step 707
  • the forwarding rule indicates that the first uplink data packet forwarding rule in the
  • the first downlink data packet detection rule in the information is obtained by adding the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element, and the first downlink data packet forwarding rule in step 707 is an intermediate session
  • the management network element indicates that the first downlink data packet forwarding rule in the third N4 information in step 706 adds the tunnel endpoint identifier of the target offload user plane network element and the target offload user Obtain the IP address of the plane network element.
  • the intermediate session management function according to the forwarding tunnel rule in the first N4 information in step 706 Indicates that it is necessary to establish a data packet forwarding tunnel to ensure the continuity of uplink or downlink service data packets in the process of offloading user plane functions and changing user plane functions at the same time. Then the first uplink data packet detection rule, the first uplink data packet forwarding rule, the first downlink data packet detection rule and the first downlink data packet forwarding rule in step 707 are generated by the intermediate session management network element.
  • the first uplink data packet detection rule in step 707 is the same as the first data packet detection rule sent by the intermediate session management network element to the source offload user plane network element in step 405 in FIG.
  • the session management network element adds the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element to the second data packet detection rule according to the sixth indication information.
  • the first uplink data packet forwarding rule in step 707 is the same as the first data packet forwarding rule sent by the intermediate session management network element to the source distribution user plane network element in step 405 in FIG.
  • the element is obtained by adding the tunnel endpoint identifier of the source user plane network element and the IP address of the source user plane network element to the second data packet forwarding rule according to the sixth indication information.
  • the first downlink data packet detection rule in step 707 is the same as the third data packet detection rule sent by the intermediate session management network element to the source distribution user plane network element in step 501 in Figure 5, and the third data packet detection rule is the intermediate session management
  • the network element obtains it by adding the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element to the fourth data packet detection rule according to the seventh indication information.
  • the first downlink data packet forwarding rule in step 707 is the same as the third data packet forwarding rule sent by the intermediate session management network element to the source distribution user plane network element in step 405 in Figure 4, and the third data packet forwarding rule is the intermediate session management The network element obtains it by adding the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element to the fourth data packet forwarding rule according to the seventh instruction information.
  • the source offload user plane network element replies the first PFCP session update response message to the intermediate session management network element, and the first PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the first PFCP session update response message from the source offload user plane network element.
  • the first PFCP session update response message in step 708 includes the service data packet forwarding information assigned by the source offload user plane network element, and the service data packet forwarding information includes the tunnel endpoint identifier of the source offload user plane network element and the source offload user plane The IP address of the network element.
  • the service data packet forwarding information is used by the target offload user plane network element to establish a forwarding channel of the uplink service data packet to ensure the continuity of the uplink service data packet.
  • the intermediate session management network element sends a second PFCP session update request message to the target offload user plane network element, and the second PFCP session update request message is used to notify the target offload user plane network element to update the PFCP session of the terminal device.
  • the target offload user plane network element receives the second PFCP session update request message from the intermediate session management network element.
  • the second PFCP session update request message in step 709 includes the second uplink data packet detection rule, the second uplink data packet forwarding rule, the second downlink data packet detection rule, the second Downlink data packet forwarding rule, third uplink data packet detection rule, third uplink data packet forwarding rule, third downlink data packet detection rule and third downlink data packet forwarding rule.
  • the associated forwarding tunnel rule indicates that the third uplink data packet detection rule and the third uplink data packet forwarding rule are determined, the third downlink data packet detection rule and the third downlink data packet forwarding rule are to ensure The continuity of the uplink or downlink service data packets in the process of changing the surface function at the same time requires that after the data packet forwarding tunnel is established, the third uplink data packet detection rule in step 709 is that the intermediate session management network element according to the first N4 in step 706
  • the forwarding tunnel rule indication in the information is obtained by adding the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element to the third uplink data packet detection rule in the first N4 information in step 706, step 709
  • the tunnel endpoint identifier of the plane network element and the Internet Protocol address of the source offload user plane network element are obtained, and the first downlink data packet detection rule in step 709 is that the intermediate session management network element according to the forwarding tunnel in the first N4 information of step 706
  • the rule indicates that the first downlink data packet detection rule in the first N4 information in step 706 is obtained by adding the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element, and the first downlink data packet detection rule in step 709
  • the downlink data packet forwarding rule indicates that the intermediate session management network element adds the target access network device to the first downlink data packet forwarding rule in the first N4 information in step 706 according to the forwarding tunnel rule in the first N4 information in step 706
  • the tunnel endpoint identifier and the IP address of the target access network device are obtained.
  • the third uplink data packet detection rule in step 709 is the same as the first data packet detection rule sent by the intermediate session management network element to the target offload user plane network element in step 405 in FIG.
  • the session management network element adds the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element to the second data packet detection rule according to the sixth indication information.
  • the third uplink data packet forwarding rule in step 709 is the same as the first data packet forwarding rule sent by the intermediate session management network element to the target offload user plane network element in step 405 in FIG.
  • the element is obtained by adding the tunnel endpoint identifier of the source offload user plane network element and the IP address of the source offload user plane network element to the second data packet forwarding rule according to the sixth indication information.
  • the third downlink data packet detection rule in step 707 is the same as the third data packet detection rule sent by the intermediate session management network element to the target offload user plane network element in step 501 in Figure 5, and the third data packet detection rule is the intermediate session management network element
  • the element is obtained by adding the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element to the fourth data packet detection rule according to the seventh instruction information.
  • the third downlink data packet forwarding rule in step 707 is the same as the third data packet forwarding rule sent by the intermediate session management network element to the target offload user plane network element in step 405 in FIG.
  • the element is obtained by adding the tunnel endpoint identifier of the target access network device and the IP address of the target access network device to the fourth data packet forwarding rule according to the seventh instruction information.
  • Table 3 shows the correspondence between the data packet detection rule, the data packet forwarding rule, and the forwarding tunnel rule indication.
  • Table 3 Correspondence between packet inspection rules, packet forwarding rules, and forwarding tunnel rule indications
  • the service data packet forwarding information in the PDR and the service data packet forwarding information in the FAR need to be included by the intermediate session management network element to the second Uplink data packet detection rule, second uplink data packet forwarding rule, second downlink data packet detection rule and second downlink data packet forwarding rule, third uplink data packet detection rule and third uplink data packet forwarding rule, third downlink data packet In the packet inspection rule and the third downlink data packet forwarding rule.
  • Service data packet forwarding allocated by network elements such as target offloading user plane network elements to ensure the continuity of uplink or downlink service data packets in the process of simultaneous change of offloading user plane network elements and user plane network elements
  • the intermediate session management network element needs to indicate the rules for distinguishing the above two cases according to the forwarding tunnel rules, and add corresponding service data packet forwarding information.
  • DL PDR 258 (identification of the third downlink data packet detection rule), the fourth service data packet forwarding information allocated by the target offload user plane network element, Core (source interface), N9 (source interface type), DL FAR 258 (identification of the third downlink data packet forwarding rule), the first service data packet forwarding information assigned by the target access network device, Access (target interface), N3 (target interface type), forwarding tunnel rule indication (Y) There is a corresponding relationship between them. Because the indication of the forwarding tunnel rule is Y, it means that the third downlink data packet detection rule, the third downlink data packet forwarding rule, etc. are used to ensure the continuity of the downlink business data packets.
  • UL PDR 259 (the identification of the third uplink data packet detection rule), the third service data packet forwarding information allocated by the target offload user plane network element, Access (source interface), N3 (source interface type), UL FAR 259 (Identification of the third uplink data packet forwarding rule), service data packet forwarding information assigned by the source offload user plane network element, Core (target interface), N9 (target interface type), and forwarding tunnel rule indication (Y)
  • Y forwarding tunnel rule indication
  • DL PDR 256 (the identification of the second downlink data packet detection rule), the second service data packet forwarding information assigned by the target offload user plane network element, Core (source interface), N9 (source interface type), DL FAR 256 ( The identification of the second downlink data packet forwarding rule), the second service data packet forwarding information assigned by the target access network device, Access (target interface), N3 (target interface type), and forwarding tunnel rule indication (N) relation. Because the indication of the forwarding tunnel rule is N, it indicates that the second downlink data packet detection rule, the second downlink data packet forwarding rule, etc. are the service data packet forwarding information allocated for normal service data packet forwarding.
  • UL PDR 257 (identification of the second uplink data packet detection rule), the forwarding information of the first service data packet allocated by the target offload user plane network element, Access (source interface), N3 (source interface type), UL FAR 257 (identification of the second uplink data packet forwarding rule), service data packet forwarding information assigned by the target user plane network element, Core (target interface), N9 (target interface type), and forwarding tunnel rule indication (N)
  • N forwarding tunnel rule indication
  • the intermediate session management network element receives the second PFCP session update response message from the target offload user plane network element.
  • the second PFCP session update response message in step 710 includes the third service data packet forwarding information and the fourth service data packet forwarding information assigned by the target offload user plane network element.
  • Both the third service data packet forwarding information and the fourth service data packet forwarding information include the tunnel endpoint identifier of the target offload user plane network element and the IP address of the target offload user plane network element.
  • the forwarding information of the third service data packet is used by the source access network device to establish the forwarding channel of the uplink service data packet in order to ensure the continuity of the uplink service data packet
  • the forwarding information of the fourth service data packet is used by the source offloading user plane network
  • the element establishes a forwarding channel of the downlink service data packet to ensure the continuity of the downlink service data packet.
  • step 710 the downlink service data packet forwarding path:
  • the session management network element sends a third PFCP session update request message to the remote user plane network element, and the third PFCP session update request message is used to notify the remote user plane network element to update the PFCP session of the terminal device.
  • the remote user plane network element receives the third PFCP session update request message from the session management network element.
  • the third PFCP session update request message in step 711 includes the second service data packet forwarding information allocated by the target offload user plane network element in step 705, for the remote user plane network element to receive downlink service data from the data network After the packet is packaged, the second service data packet is sent to the target offload user plane network element according to the second service data packet forwarding information allocated by the target offload user plane network element.
  • the remote user plane network element replies a third PFCP session update response message to the session management network element, and the third PFCP session update response message indicates that the PFCP session is successfully updated.
  • the session management network element receives the third PFCP session update response message from the remote user plane network element.
  • step 712 the downlink service data packet forwarding path:
  • the intermediate session management network element sends a fourth PFCP session update request message to the target user plane network element, and the fourth PFCP session update request message is used to notify the target user plane network element to update the PFCP session of the terminal device.
  • the target user plane network element receives the fourth PFCP session update request message from the intermediate session management network element.
  • the fourth PFCP session update request message in step 713 includes the second uplink data packet detection rule, the second uplink data packet forwarding rule, the second downlink data packet detection rule and the second uplink data packet detection rule included in the second N4 information in step 706. Downlink data packet forwarding rules.
  • the fourth PFCP session update request message in step 713 also includes third indication information.
  • third indication information reference may be made to the relevant description of step 403 in FIG. 4 , and details are not repeated here.
  • the intermediate session management network element forwards the third indication information to the target user plane network element; for case 1.1 in step 706, the intermediate session management network element forwards the The second indication information is to set the buffer bit in the forwarding action information element included in the second uplink data packet forwarding rule sent to the target user plane network element to 1 to instruct the target user plane network element to cache the uplink data packet.
  • the target user plane network element replies a fourth PFCP session update response message to the intermediate session management network element, and the fourth PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the fourth PFCP session update response message from the target user plane network element.
  • step 714 the downlink service data packet forwarding path:
  • the intermediate session management network element sends a PDU session resource update request message to the target access network device, and the PDU session resource update request message includes the forwarding information of the first service data packet in step 704.
  • the target access network device receives a PDU session resource update request message from the intermediate session management network element.
  • the target access network device replies a PDU session resource update response message to the intermediate session management network element, and the PDU session resource update response message indicates that the PDU session resource update is successful.
  • the intermediate session management network element receives the PDU session resource update response message from the target access network device.
  • step 716 the uplink service data packet forwarding path:
  • this solution may also include but not limited to the following steps 717-724.
  • FIG. 7C is a schematic flowchart of another message transmission method provided by the embodiment of this application.
  • the session management network element waits for the confirmation message from the target application network element.
  • the session management network element After the session management network element receives the confirmation message from the target application network element, the session management network element sends the second PDU session update message (Nsmf_PDUSession_Update request) to the intermediate session management network element, and the second PDU session update message contains the fourth indication information .
  • step 718 is the same as step 618 in FIG. 6C , and will not be repeated here.
  • the intermediate session management network element replies the second PDU session update response message to the session management network element (Nsmf_PDUSession_Update response), and the second PDU session update response message indicates that the second PDU session update is successful.
  • the session management network element receives the second PDU session update response message from the intermediate session management network element.
  • the intermediate session management network element sends a fifth PFCP session update request message to the target user plane network element, and the user of the fifth PFCP session update request message notifies the target user plane network element to update the PFCP session of the terminal device.
  • step 720 is the same as step 620 in FIG. 6C , and will not be repeated here.
  • the target user plane network element replies with a fifth PFCP session update response message, and the fifth PFCP session update response message indicates that the PFCP session is successfully updated.
  • the intermediate session management network element receives the fifth PFCP session update response message from the target user plane network element.
  • step 712 the uplink service data packet forwarding path:
  • the source offload user plane network element When the source offload user plane network element does not forward the service data packet within the preset time, it sends a PFCP session report to the intermediate session management network element, and the PFCP session report is used to notify the intermediate session management network element of this event, that is, the PFCP session The report is used to notify the source offloading user plane network element that the service data packet has not been forwarded within a preset time.
  • the intermediate session management network element receives the PFCP session report from the source offload user plane network element.
  • the intermediate session management network element initiates deletion of the originating session according to the PFCP session report, and sends a PFCP session deletion message to the source user plane network element.
  • the intermediate session management network element sends a PFCP session deletion message to the source distribution user plane network element.
  • the target user plane network element since the target user plane network element does not forward the uplink data packet before the target application network element completes the handover, but buffers the uplink data packet before the target application network element completes the handover, the uplink data packet is not forwarded Forwarding, avoiding the loss of uplink data packets.
  • the target user plane network element since the target user plane network element forwards the uplink data packet after the target application network element completes the handover, the uplink data packet can be forwarded to the target application network element, which improves the reliability of data packet transmission. At the same time, the loss of uplink or downlink data packets of the terminal equipment is avoided, and the continuity and reliability of data packet transmission are improved.
  • the present application also provides a communication system, which includes an intermediate session management network element, a session management network element, and a target user plane network element, wherein the intermediate session management network element is used to implement the intermediate session management network element in FIG. 4 Actions to be executed; the session management network element is used to implement the actions performed by the session management network element in FIG. 4 ; the target user plane network element is used to implement the actions performed by the target user plane network element in FIG. 4 .
  • the communication system further includes a user plane network element
  • the user plane network element includes a source offload user plane network element and/or a target offload user plane network element, and an intermediate session management network element, which is used to realize the The actions performed by the intermediate session management network element;
  • the session management network element is used to implement the actions performed by the session management network element in Figure 6A- Figure 7C;
  • the target user plane network element is used to implement the actions performed by the target user in Figure 6A- Figure 7C
  • the actions performed by the network elements of the source offloading user plane are used to implement the actions performed by the user plane network elements of source offloading in Figure 6A-7C;
  • the target offloading user plane network elements are used to implement the actions in Figure 6A- Figure 7C Actions performed by the target offload user plane NE.
  • the communication system also includes a target access network device, a source user plane network element, a remote user plane network element, and a target access network device, which are used to implement the actions performed by the target access network device in Figures 6A-7C ;
  • the source user plane network element is used to implement the actions performed by the source user plane network element in Figure 6A- Figure 7C;
  • the remote user plane network element is used to implement the actions performed by the remote user plane network element in Figure 6A- Figure 7C Actions.
  • the present application also provides yet another communication system, the communication system includes an intermediate session management network element and a user plane network element, and the user plane network element includes a source offload user plane network element and/or a target offload user plane network element, wherein the intermediate The session management network element is used to implement the actions performed by the intermediate session management network element in Figure 5- Figure 7C; the source offload user plane network element is used to implement the actions performed by the source offload user plane network element in Figure 5- Figure 7C ; The target offloading user plane network element is used to realize the actions performed by the target offloading user plane network element in FIGS. 5-7C .
  • the communication system also includes a session management network element and a target user network element.
  • the session management network element is used to realize the actions performed by the session management network element in FIG. 6A-FIG. 7C; the target user plane network element is used to realize the 6A-actions performed by the target user plane network element in FIG. 7C.
  • the communication system also includes a target access network device, a source user plane network element, a remote user plane network element, and a target access network device, which are used to implement the actions performed by the target access network device in Figures 6A-7C ;
  • the source user plane network element is used to implement the actions performed by the source user plane network element in Figure 6A- Figure 7C;
  • the remote user plane network element is used to implement the actions performed by the remote user plane network element in Figure 6A- Figure 7C Actions.
  • each network element includes a corresponding hardware structure and/or software module for performing each function.
  • the present application can be implemented in the form of hardware or a combination of hardware and computer software in combination with the units and algorithm steps of each example described in the embodiments disclosed herein. Whether a certain function is executed by hardware or computer software drives hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.
  • the embodiment of the present application can perform functions on intermediate session management network elements, user plane network elements (such as source offload user plane network elements, target offload user plane network elements, target user plane network elements, etc.) and session management network elements according to the above method example
  • the division of modules for example, can divide each functional module corresponding to each function, or integrate two or more functions into one processing module.
  • the above-mentioned integrated modules can be implemented in the form of hardware or software functions implemented in the form of modules. It should be noted that the division of modules in the embodiment of the present application is schematic, and is only a logical function division, and there may be other division methods in actual implementation.
  • FIG. 8 is a schematic structural diagram of a communication device provided in an embodiment of the present application.
  • the communication device 800 can be applied to the methods shown in FIGS. 4-7C above.
  • the communication device 800 includes: a transceiver module 801 .
  • the transceiver module 801 may be a transceiver or a communication interface.
  • the communication device can be used to implement the intermediate session management network element, user plane network element (such as source offload user plane network element, target offload user plane network element, target user plane network element, etc.) or session management in any of the above method embodiments.
  • user plane network element such as source offload user plane network element, target offload user plane network element, target user plane network element, etc.
  • the network element or network function may be a network element in a hardware device, or a software function running on dedicated hardware, or a virtualization function instantiated on a platform (for example, a cloud platform).
  • the communication device 800 may further include a processing module 802 and a storage module 803.
  • the processing module 802 may be one or more processors, and the processing module 802 may be used to support the communication device 800 to execute the processing actions in the foregoing method embodiments.
  • the storage module 803 is used for storing program codes and data of the communication device 800 .
  • the transceiver module 801 is used to support communication with session management network elements and user plane network elements (such as source offload user plane network elements, target offload user plane network elements, target user plane network elements, etc.), and the specific execution diagram of the transceiver module 4-
  • the sending and/or receiving action performed by the intermediate session management network element in FIG. 7C supports the intermediate session management network element to perform one or more steps in step 401 and step 403, and/or is used for the Other procedures of the described technique.
  • the communication device is used as a session management network element or a chip applied to the session management network element, and executes the steps performed by the session management network element in the above method embodiments.
  • the transceiver module 801 is used to support communication with intermediate session management network elements, etc., and the transceiver module specifically executes the sending and/or receiving actions performed by the session management network element in Figure 4- Figure 7C, for example, supports the session management network element to perform One or more of steps 402 and 404, and/or other processes for the techniques described herein.
  • the communication device when used as a source offload user plane network element or a chip applied to a source offload user plane network element, and executes the steps performed by the source offload user plane network element in the above method embodiments.
  • the transceiver module 801 is used to support communication with intermediate session management network elements, etc., and the transceiver module specifically performs the sending and/or receiving actions performed by the source offload user plane network element in Figure 4- Figure 7C, for example, supporting source offload user plane
  • the plane network element performs one or more steps in step 604 and step 616, and/or other processes for the techniques described herein.
  • the communication device when used as a target offload user plane network element or a chip applied to the target offload user plane network element, and executes the steps performed by the target offload user plane network element in the above method embodiments.
  • the transceiver module 801 is used to support communication with intermediate session management network elements, etc.
  • the transceiver module specifically performs the sending and/or receiving actions performed by the target offload user plane network element in Figure 4- Figure 7C, such as supporting target offload user
  • the plane network element performs one or more steps in step 602 and step 610, and/or other processes for the techniques described herein.
  • the transceiver module 801 is used to support communication with intermediate session management network elements, etc.
  • the transceiver module specifically performs the sending and/or receiving actions performed by the target user plane network element in Figure 4- Figure 7C, such as supporting the target user plane network element Other processes that perform the techniques described herein.
  • the transceiver module 801 may be an interface , pins or circuits, etc.
  • the interface can be used to input the data to be processed to the processor, and can output the processing result of the processor.
  • the interface can be a general purpose input output (GPIO) interface, which can communicate with multiple peripheral devices (such as display (LCD), camera (camara), radio frequency (radio frequency, RF) modules, antennas, etc. ) connect.
  • the interface is connected with the processor through the bus.
  • the interface can also be understood as a communication interface.
  • the processing module 802 may be a processor, and the processor may execute computer-executed instructions stored in the storage module, so that the chip executes the methods involved in the above-mentioned embodiments.
  • the processor may include a controller, an arithmetic unit and registers.
  • the controller is mainly responsible for decoding instructions and sending control signals for operations corresponding to the instructions.
  • the arithmetic unit is mainly responsible for performing fixed-point or floating-point arithmetic operations, shift operations, and logic operations, and can also perform address operations and conversions.
  • the register is mainly responsible for saving the register operands and intermediate operation results temporarily stored during the execution of the instruction.
  • the hardware architecture of the processor can be an application-specific integrated circuit architecture, a microprocessor without interlocked piped stages architecture (MIPS) architecture, an advanced RISC machines (Advanced RISC machines, ARM ) architecture or network processor (network processor, NP) architecture and so on. Processors can be single-core or multi-core.
  • the storage module 803 may be a storage module in the chip, such as a register, a cache, and the like.
  • the storage module 803 may also be a storage module located outside the chip, such as ROM or other types of static storage devices that can store static information and instructions, RAM, and the like.
  • processors and the interface can be realized through hardware design, software design, or a combination of software and hardware, which is not limited here.
  • the embodiment of the present application also provides a communication device, including a processor, a memory, an input interface and an output interface, the input interface is used to receive information from other communication devices other than the communication device, and the output interface is used to send information to other communication devices outside the communication device Other communication devices output information, and the processor invokes the computer program stored in the memory to implement any of the embodiments shown in FIGS. 4-8 .
  • An embodiment of the present application also provides a computer-readable storage medium, in which a computer program is stored. When the computer program is run, any one of the embodiments shown in FIGS. 4-8 is implemented.
  • the embodiment of the present application also provides a chip.
  • the chip includes at least one processor and an interface.
  • the processor is used to read and execute the instructions stored in the memory. When the instructions are executed, the chip executes any an embodiment.
  • the embodiment of the present application also provides a computer program product including instructions, which, when executed on a computer, enables any one of the embodiments shown in FIG. 4 to FIG. 8 to be executed.
  • each network element unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.
  • the above-mentioned integrated units can be implemented in the form of hardware or in the form of software network elements.
  • the above integrated units are realized in the form of software network elements and sold or used as independent products, they can be stored in a computer-readable storage medium.
  • the technical solution of the present application essentially makes a contribution, or all or part of the technical solution can be embodied in the form of a software product, the computer software product is stored in a storage medium, including several instructions for So that a computer device (which may be a personal computer, a cloud server, or a network device, etc.) executes all or part of the steps of the above-mentioned methods in various embodiments of the present application.
  • the aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disc, etc., which can store program codes. .
  • U disk mobile hard disk
  • read-only memory ROM, Read-Only Memory
  • RAM random access memory
  • magnetic disk or optical disc etc.
  • the above is only a specific embodiment of the application, but the scope of protection of the application is not limited thereto. Any person familiar with the technical field can easily think of various equivalents within the scope of the technology disclosed in the application. Modifications or replacements, these modifications or replacements shall be covered within the scope of protection of this application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

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Abstract

本申请提供了一种指示信息的传输方法、消息传输方法及相关装置，该方法包括：中间会话管理网元根据来自会话管理网元的第二指示信息向目标用户面网元发送第三指示信息，使得目标用户面网元根据第三指示信息缓存上行数据包，当会话管理网元获知目标应用网元已完成切换时，可以向中间会话管理网元发送第四指示信息，使得中间会话管理网元根据第四指示信息向目标用户面网元发送第五指示信息，进而让目标用户面网元根据第五指示信息转发上行数据包，这避免了数据包的丢失，提高了数据包传输的可靠性。

Description

指示信息的传输方法、消息传输方法及相关装置
本申请要求在2021年10月26日提交中国专利局、申请号为202111245179.3、发明名称为“指示信息的传输方法、消息传输方法及相关装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及通信技术领域，尤其涉及一种指示信息的传输方法、消息传输方法及相关装置。
背景技术
第五代移动通信技术(5th generation mobile networks，5G)网络中终端设备的数据流可以通过上行分流器(uplink classifier，UL CL)或者分流点(branching point，BP)进行分流，使得部分数据流从离终端设备接入位置近的本地会话锚点转发，其他数据流从离终端设备接入位置远的远端会话锚点转发，进而在应用服务器部署位置较低时，可以缩短数据包转发路径，降低时延。
当终端设备移动时，可能会导致上行分流器和本地会话锚点同时改变，或，分流点和本地会话锚点同时改变。在这种情况下，可能会存在数据包丢失的情况。因此，如何避免数据包丢失、提高数据包传输的可靠性成为当前亟待解决的问题。
发明内容
本申请提供了一种指示信息的传输方法、消息传输方法及相关装置，可以避免数据包的丢失，提高了数据包传输的可靠性。
第一方面，提供一种指示信息的传输方法，该方法包括：中间会话管理网元向会话管理网元发送第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。接着，中间会话管理网元从会话管理网元接收第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。中间会话管理网元根据第二指示信息，向目标用户面网元发送第三指示信息，第三指示信息用于指示目标用户面网元缓存上行数据包。中间会话管理网元从会话管理网元接收第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包。中间会话管理网元根据第四指示信息，向目标用户面网元发送第五指示信息，第五指示信息用于指示目标用户面网元转发上行数据包。换句话来说，中间会话管理网元可以向会话管理网元发送第一指示信息，使得会话管理网元可以获知中间会话管理网元已插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元，从而可以使得中间会话管理网元根据来自会话管理网元的第二指示信息向目标用户面网元发送第三指示信息，进而让目标用户面网元根据第三指示信息缓存上行数据包。同时，当会话管理网元获知目标应用网元已完成切换时，可以向中间会话管理网元发送第四指示信息，使得中间会话管理网元根据第四指示信息向目标用户面网元发送第五指示信息，进而让目标用户面网元根据第五指示信息转发上行数据包。可以理解的，由于目标用户面网元未在目标应用网元完成切换前转发上行数据包，而是在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避 免了上行数据包的丢失。另外，由于目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。
可选的，该方法还包括：中间会话管理网元向用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则(packet detection rule,PDR)和第一数据包转发规则(forwarding action rule，FAR)。
其中，若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
其中，若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。即中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第一数据包检测规则检测数据包，并按照第一数据包转发规则转发数据包，使得在目标应用网元完成切换之前，上行数据包从源用户面网元发往源应用网元，避免了终端设备的上行数据包的丢失和中断，提高了数据包传输的连续性和可靠性。
可选的，该方法还包括：中间会话管理网元从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息。其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。换句话来说，中间会话管理网元可以从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息，使得中间会话管理网元可以获知以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。
若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
可以看出，上述技术方案中，由于第一数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第一数据包转发规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址和源分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失和中断。同理，由于第一数据包检测规则中还包括源分流用户面网元的隧道端点 标识和源分流用户面网元的网际协议地址、第一数据包转发规则中还包括源用户面网元的隧道端点标识和源用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据源用户面网元的隧道端点标识和源用户面网元的网际协议地址和源用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失和中断。
第二方面，提供一种消息传输方法，该方法包括：中间会话管理网元向用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
其中，若用户面网元为源分流用户面网元，第三数据包检测规则为源分流用户面网元检测来自远端用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。
其中，若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。即，中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息中包括第三数据包检测规则和第三数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第三数据包检测规则检测数据包，并按照第三数据包转发规则转发数据包，避免了终端设备的下行数据包的丢失和中断，提高了数据包传输的连续性和可靠性。
可选的，该方法还包括：中间会话管理网元从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息。其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可以看出，上述技术方案中，中间会话管理网元可以从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息，使得中间会话管理网元可以获知以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。可以理解的，由于第三数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标接入网设 备的隧道端点标识和目标接入网设备的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址和目标接入网设备建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。同理，由于第三数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址和目标分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。
第三方面，提供一种指示信息的传输方法，该方法包括：会话管理网元从中间会话管理网元接收第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。会话管理网元根据第一指示信息向中间会话管理网元发送第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。会话管理网元向中间会话管理网元发送第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包，第四指示信息为会话管理网元获知目标应用网元已完成切换后发送的指示信息。换句话来说，会话管理网元可以从中间会话管理网元接收第一指示信息，使得会话管理网元可以获知中间会话管理网元已插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元，并根据第一指示信息向中间会话管理网元发送第二指示信息，实现了目标用户面网元在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。同时，会话管理网元向中间会话管理网元发送第四指示信息，实现了目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。
可选的，该方法还包括：会话管理网元向中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息。其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。即会话管理网元可以向中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息，使得中间会话管理网元可以获知以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
第四方面，提供一种指示信息的传输方法，该方法包括：用户面网元从中间会话管理网元接收第三指示信息，第三指示信息用于指示用户面网元缓存上行数据包。用户面网元从中间会话管理网元接收第五指示信息，第五指示信息用于指示用户面网元转发上行数据包。换句话来说，用户面网元可以从中间会话管理网元接收用于指示用户面网元缓存上行数据包的第三指示信息，实现了目标用户面网元在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。同时，用户面网元可以从中间会话管理网元接收用于指示用户面网元转发上行数据包的第五指示信息，实现了目标用户面网元在目 标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。
可选的，该方法还包括：用户面网元从中间会话管理网元接收第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。
其中，若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
其中，若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。即源分流用户面网元或目标分流用户面网元可以从中间会话管理网元接收第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第一数据包检测规则检测数据包，并按照第一数据包转发规则转发数据包，使得在目标应用网元完成切换之前，上行数据包从源用户面网元发往源应用网元，避免了终端设备的上行数据包的丢失和中断，提高了数据包传输的连续性和可靠性。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。
若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。可以理解的，由于第一数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第一数据包转发规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收和检测数据包，根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址和源分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失。同理，由于第一数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第一数据包转发规则中还包括源用户面网元的隧道端点标识和源用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据源用户面网元的隧道端点标识和源用户面网元的网际协议地址和源用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失。
第五方面，提供一种消息传输方法，该方法包括：用户面网元从中间会话管理网元接收第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
若用户面网元为源分流用户面网元，第三数据包检测规则为源分流用户面网元检测来自远端用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。即源分流用户面网元或目标分流用户面网元可以从中间会话管理网元接收第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息中包括第三数据包检测规则和第三数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第三数据包检测规则检测数据包，并按照第三数据包转发规则转发数据包，避免了终端设备的下行数据包的丢失，提高了数据包传输的可靠性。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。可以理解的，由于第三数据包检测规则还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址和目标接入网设备建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。同理，由于第三数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包、第三数据包转发规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址和目标分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。
第六方面，提供一种指示信息的传输方法，该方法包括：中间会话管理网元向会话管理网元发送第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。会话管理网元根据第一指示信息向中间会话管理网元发送第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。目标用户面网元从中间会话管理网元接收第三指示信息，第三指示信息为中间会话管理网元根据第二指示信息发送，第三指示信息用于指示目标用户面网元缓存上行数据包。
会话管理网元向中间会话管理网元发送第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包，第四指示信息为会话管理网元获知目标应用网元已完成切换后发送的指示信息。中间会话管理网元根据第四指示信息，向目标用户面网元发送第五指示信息，第五指示信息用于指示目标用户面网元转发上行数据包。
可以看出，上述技术方案中，由于目标用户面网元未在目标应用网元完成切换前转发上行数据包，而是在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。另外，由于目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。
可选的，该方法还包括：中间会话管理网元向用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。
若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。
可以看出，上述技术方案中，中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第一数据包检测规则检测数据包，并按照第一数据包转发规则转发数据包，避免了终端设备的上行数据包的丢失，提高了数据包传输的可靠性。
可选的，该方法还包括：会话管理网元向中间会话管理网元第二数据包检测规则、第二数据包转发规则和第六指示信息。其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可以看出，上述技术方案中，会话管理网元可以向中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息，使得中间会话管理网元可以获知以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网 元的网际协议地址得到。
若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
可以看出，上述技术方案中，由于第一数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第一数据包转发规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址和源分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。同理，由于第一数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第一数据包转发规则中还包括源用户面网元的隧道端点标识和源用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据源用户面网元的隧道端点标识和源用户面网元的网际协议地址和源用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。
第七方面，提供一种消息传输方法，该方法包括：中间会话管理网元向用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
若用户面网元为源分流用户面网元，第三数据包检测规则为源分流用户面网元检测来自远端用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。
可以看出，上述技术方案中，中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息中包括第三数据包检测规则和第三数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第三数据包检测规则检测数据包，并按照第三数据包转发规则转发数据包，避免了终端设备的下行数据包的丢失，提高了数据包传输的可靠性。
可选的，该方法还包括：会话管理网元向中间会话管理网元发送第四数据包检测规则、第四数据包转发规则和第七指示信息。其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可以看出，上述技术方案中，会话管理网元可以向中间会话管理网元发送第四数据包检测规则、第四数据包转发规则和第七指示信息，使得中间会话管理网元可以获知以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规 则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
可以看出，上述技术方案中，由于第三数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址和目标接入网设备建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。同理，由于第三数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址和目标分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。
第八方面，提供一种中间会话管理网元，中间会话管理网元包括收发模块，收发模块，用于向会话管理网元发送第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。
收发模块，用于从会话管理网元接收第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。
收发模块，用于根据第二指示信息，向目标用户面网元发送第三指示信息，第三指示信息用于指示目标用户面网元缓存上行数据包。
收发模块，用于从会话管理网元接收第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包。
收发模块，用于根据第四指示信息，向目标用户面网元发送第五指示信息，第五指示信息用于指示目标用户面网元转发上行数据包。
可选的，收发模块，还用于向用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。
若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测 来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。
可选的，收发模块，还用于从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息。其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。
若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
第九方面，提供一种中间会话管理网元，中间会话管理网元包括收发模块，收发模块，用于向用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
若用户面网元为源分流用户面网元，第三数据包检测规则为源分流用户面网元检测来自远端用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。
可选的，收发模块，还用于从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息。其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网的隧道端点标识和目标分流用户面网的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
第十方面，提供一种会话管理网元，会话管理网元包括收发模块，收发模块，用于从中间会话管理网元接收第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。收发模块，用于根据第一指示信息向中间会话管理网元发送第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。收发模块，用于向中间会话管理网元发送第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包，第四指示信息为会话管理网元获知目标应用网元已完成切换后发送的指示信息。
可选的，收发模块，还用于向中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息。其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
第十一方面，提供一种用户面网元，用户面网元包括收发模块，收发模块，用于从中间会话管理网元接收第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。
若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。
可选的，收发模块，还用于从中间会话管理网元接收第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。
若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。
若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元 或目标分流用户面网元转发数据包对应的规则。
第十二方面，提供一种用户面网元，用户面网元包括收发模块，收发模块，用于从中间会话管理网元接收第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
若用户面网元为源分流用户面网元，第三数据包检测规则为源分流用户面网元检测来自远端用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。
若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
第十三方面，提供一种通信装置，包括处理器、存储器、输入接口和输出接口，输入接口用于接收来自通信装置之外的其它通信装置的信息，输出接口用于向通信装置之外的其它通信装置输出信息，处理器调用存储器中存储的计算机程序实现如第一方面或第二方面或第三方面或第四方面或第五方面任意一项的方法。
在一种可能的设计中，该通信装置可以是实现第一方面、第二方面或第三方面或第四方面或第五方面中任意一项方法的芯片或者包含芯片的设备。
第十四方面，提供一种计算机可读存储介质，计算机可读存储介质中存储有计算机程序，当计算机程序被运行时，实现如第一方面或第二方面或第三方面或第四方面或第五方面任意一项的方法。
第十五方面，提供一种芯片，芯片包括至少一个处理器和接口，处理器用于读取并执行存储器中存储的指令，当指令被运行时，使得芯片执行如第一方面或第二方面或第三方面或第四方面或第五方面任意一项的方法。
第十六方面，提供一种包含指令的计算机程序产品，当其在计算机上执行时，使得第一方面或第二方面或第三方面或第四方面或第五方面任意一项的方法被执行。
第十七方面，提供一种通信系统，该通信系统包括以下一项或多项：中间会话管理网元、会话管理网元、用户面网元。其中，用户面网元包括以下一项或多项：目标用户面网元、源分流用户面网元、目标分流用户面网元。
第十八方面，提供一种通信系统，该通信系统包括中间会话管理网元、会话管理网元和用户面网元，中间会话管理网元用于执行第一方面中任一项所述的方法，会话管理网元用于执行第三方面中任一项所述的方法，用户面网元用于执行第四方面中任一项所述的方法。
第十九方面，提供一种通信系统，该通信系统包括中间会话管理网元和用户面网元，中间会话管理网元用于执行第二方面所述的方法，用户面网元用于执行第五方面中任一项所述的方法。
附图说明
下面将对实施例描述中所需要使用的附图作简单地介绍。
其中：
图1为本申请实施例提供的通信系统的基础架构；
图2A为基于服务化架构的5G网络架构示意图；
图2B为基于点对点接口的5G网络架构示意图；
图3所示为可适用于本申请实施例提供的通信装置的硬件结构示意图；
图4为本申请实施例提供的一种指示信息的传输方法的流程示意图；
图5为本申请实施例提供的一种消息传输方法的流程示意图；
图6A为本申请实施例提供的又一种消息传输方法的流程示意图；
图6B为本申请实施例提供的又一种消息传输方法的流程示意图；
图6C为本申请实施例提供的又一种消息传输方法的流程示意图；
图7A为本申请实施例提供的又一种消息传输方法的流程示意图；
图7B为本申请实施例提供的又一种消息传输方法的流程示意图；
图7C为本申请实施例提供的又一种消息传输方法的流程示意图；
图8为本申请实施例提供的一种通信装置的结构示意图。
具体实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行描述。其中，本申请实施例中的术语“系统”和“网络”可被互换使用。除非另有说明，“/”表示前后关联的对象是一种“或”的关系，例如，A/B可以表示A或B；本申请中的“和/或”仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况，其中A,B可以是单数或者复数。并且，在本申请的描述中，除非另有说明，“多个”是指两个或多于两个。“以下至少一项(个)”或其类似 表达，是指的这些项中的任意组合，包括单项(个)或复数项(个)的任意组合。例如，a，b，或c中的至少一项(个)，可以表示：a，b，c，a-b，a-c，b-c，或a-b-c，其中a，b，c可以是一个，也可以是多个。另外，为了便于清楚描述本申请实施例的技术方案，在本申请的实施例中，采用了“第一”、“第二”等字样对网元和作用基本相同的相同项或相似项进行区分。本领域技术人员可以理解“第一”、“第二”等字样并不对数量和执行次序进行限定，并且“第一”、“第二”等字样也并不限定一定不同。
在本申请实施例中描述的参考“一个实施例”或“一些实施例”等意味着在本申请的一个或多个实施例中包括结合该实施例描述的特定特征、结构或特点。由此，在本说明书中的不同之处出现的语句“在一个实施例中”、“在一些实施例中”、“在其他一些实施例中”、“在另外一些实施例中”等不是必然都参考相同的实施例，而是意味着“一个或多个但不是所有的实施例”，除非是以其他方式另外特别强调。术语“包括”、“包含”、“具有”及它们的变形都意味着“包括但不限于”，除非是以其他方式另外特别强调。
以下的具体实施方式，对本申请的目标、技术方案和有益效果进行了进一步详细说明，所应理解的是，以下仅为本申请的具体实施方式而已，并不用于限定本申请的保护范围，凡在本申请的技术方案的基础之上，所做的任何修改、等同替换、改进等，均应包括在本申请的保护范围之内。
在本申请的各个实施例中，如果没有特殊说明以及逻辑冲突，不同的实施例之间的术语和/或描述具有一致性、且可以相互引用，不同的实施例中的技术特征根据其内在的逻辑关系可以组合形成新的实施例。
应理解，本申请实施例的技术方案可以应用于第五代移动通信技术(5th generation mobile networks，5G)等。本申请实施例的技术方案还可以应用于未来其它的通信系统，例如6G通信系统等，在未来通信系统中，可能保持功能相同，但名称可能会改变。
下面介绍本申请实施例提供的通信系统的基础架构。参见图1，图1为本申请实施例提供的通信系统的基础架构。如图1所示，该通信系统可以包括以下网元中的一个或多个：中间会话管理网元、会话管理网元、用户面网元、接入网设备、终端设备、移动性管理网元、应用网元以及连接运营商网络的数据网络(data network，DN)，终端设备可通过接入网设备、用户面网元向数据网络发送数据包，以及从数据网络接收数据包。可以理解的，本申请中，数据包可以为业务数据。另外，图1仅为示意图，并不构成对本申请提供的技术方案的适用场景的限定。
其中，中间会话管理网元选择提供分流功能的分流用户面网元和本地用户面网元等。可以理解的，在终端设备移动的流程中，如Xn切换，N2切换，服务请求和跟踪区域更新等流程，中间会话管理网元可以根据终端设备所处的位置选择分流用户面网元和本地用户面网元等。在5G通信系统中，中间会话管理网元可以是中间会话管理功能(intermediate session management function，I-SMF)网元，在未来的通信系统(如6G通信系统)中，中间会话管理网元可以仍是I-SMF网元，或者也可以具有其它名称，本申请并不限定。
其中，会话管理网元主要用于移动网络中的会话管理，如会话建立、修改、释放。具体功能如为终端设备分配网际协议(internet protocol，IP)地址、选择提供报文转发功能的远端用户面网元等。在5G通信系统中，会话管理网元可以是会话管理功能(session management function，SMF)网元，在未来的通信系统(如6G通信系统)中，会话管理网元可以仍是SMF网元，或者也可以具有其它名称，本申请并不限定。
其中，用户面网元主要用于对用户报文进行处理，如转发、计费、合法监听等，可以为 远端用户面网元或本地用户面网元。远端用户面网元或本地用户面网元可以为协议数据单元会话锚点(PDU session anchor，PSA)，远端用户面网元或本地用户面网元在部署位置上不同，如本地用户面网元由中间会话管理网元选择并提供用户报文的转发，远端用户面网元由会话管理网元选择并提供用户报文的转发。另外，用户面网元也可以用于对用户报文进行分流，可以为分流用户面网元，分流用户面网元可以为上行分流器或者分流点。在5G通信系统中，用户面网元可以是用户面功能(user plane function，UPF)网元，在未来的通信系统(如6G通信系统)中，用户面网元可以仍是UPF网元，或者也可以具有其它名称，本申请并不限定。可以理解的，在本申请中，源用户面网元和目标用户面网元均为本地用户面网元，源分流用户面网元和目标分流用户面网元均为分流用户面网元。如源用户面网元可以为中间会话管理网元根据终端设备小区重选前的位置所确定的本地用户面网元，目标用户面网元可以为中间会话管理网元根据终端设备小区重选后的位置所确定的本地用户面网元，源分流用户面网元可以为中间会话管理网元根据终端设备小区重选前的位置所确定的分流用户面网元，目标分流用户面网元可以为中间会话管理网元根据终端设备小区重选后的位置所确定的分流用户面网元；或，源用户面网元可以为中间会话管理网元根据终端设备小区切换前的位置所确定的本地用户面网元，目标用户面网元可以为中间会话管理网元根据终端设备小区切换后的位置所确定的本地用户面网元，源分流用户面网元可以为中间会话管理网元根据终端设备小区切换前的位置所确定的分流用户面网元，目标分流用户面网元可以为中间会话管理网元根据终端设备小区切换后的位置所确定的分流用户面网元。
其中，接入网设备为网络侧的一种用于发送信号，或者，接收信号，或者，发送信号和接收信号的实体。接入网设备可以为部署在无线接入网(radio access network，RAN)中为终端设备提供无线通信功能的装置，例如可以为传输接收点(transmission reception point，TRP)、基站、各种形式的控制节点。例如，网络控制器、无线控制器、云无线接入网络(cloud radio access network，CRAN)场景下的无线控制器等。具体的，接入网设备可以为各种形式的宏基站，微基站(也称为小站)，中继站，接入点(access point，AP)、无线网络控制器(radio network controller，RNC)、节点B(node B，NB)、基站控制器(base station controller，BSC)、基站收发台(base transceiver station，BTS)、家庭基站(例如，home evolved nodeB，或home node B，HNB)、基带单元(baseBand unit，BBU)、发射点(transmitting point，TP)、移动交换中心)等，也可以为基站的天线面板。控制节点可以连接多个基站，并为多个基站覆盖下的多个终端配置资源。在采用不同的无线接入技术的系统中，具备基站功能的设备的名称可能会有所不同。例如，可以是5G中的gNB，或者5G之后的网络中的网络侧设备或未来演进的公共陆地移动网(public land mobile network，PLMN)网络中的接入网设备等，本申请对接入网设备的具体名称不作限定。另外，接入网设备还可以包括集成在gNB上的中心单元(central unit，CU)和分布单元(distributed unit，DU)。可以理解的，在本申请中，接入网设备可以为源接入网设备或目标接入网设备。如源接入网设备为终端设备小区重选前的接入网设备，目标接入网设备为终端设备小区重选后的接入网设备。
其中，终端设备是用户侧的一种用于接收信号，或者，发送信号，或者，接收信号和发送信号的实体。终端设备用于向用户提供语音服务和数据连通性服务中的一种或多种。终端设备可以为包含无线收发功能、且可以与接入网设备配合为用户提供通讯服务的设备。具体地，终端设备可以指用户设备(user equipment，UE)、接入终端、用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、终端、无线通信设备、用户代理或用户装置。终端设备也可以是无人机、物联网(internet of things，IoT)设备、WLAN中的站点(station， ST)、蜂窝电话(cellular phone)、智能电话(smart phone)、无绳电话、无线数据卡、平板型电脑、会话启动协议(session initiation protocol，SIP)电话、无线本地环路(wireless local loop，WLL)站、个人数字处理(personal digital assistant，PDA)设备、膝上型电脑(laptop computer)、机器类型通信(machine type communication，MTC)终端、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备(也可以称为穿戴式智能设备)、虚拟现实(virtual reality，VR)终端、增强现实(augmented reality，AR)终端、工业控制(industrial control)中的无线终端、无人驾驶(self driving)中的无线终端、远程医疗(remote medical)中的无线终端、智能电网(smart grid)中的无线终端、运输安全(transportation safety)中的无线终端、智慧城市(smart city)中的无线终端、智慧家庭(smart home)中的无线终端等。终端设备也可以是设备到设备(device to device，D2D)设备，例如，电表、水表等。终端设备还可以为5G系统中的终端，也可以为下一代通信系统中的终端，本申请实施例对此不作限定。
其中，移动性管理网元具有以下一种或多种功能：用于移动网络中的终端设备的注册、安全认证和密钥协商，非接入层(Non-Access Stratum，NAS)连接的维护，移动性管理，路由终端设备和其它网元之间的信令。例如路由终端设备和会话管理网元之间的会话管理(session management，SM)消息。在5G通信中，Namf是移动性管理网元提供的基于服务的接口，移动性管理网元可以通过Namf与其他的网络功能通信。可以理解的，本申请对移动性管理网元的名称，不作限定。如移动性管理网元，可以称为AMF网元。
其中，应用网元可以向运营商的通信网络的控制面功能提供各类应用的服务数据，或者从通信网络的控制面功能获得网络的数据信息和控制信息，或者向终端设备提供各类应用的业务数据。在5G通信系统中，应用网元可以是应用功能(application function，AF)网元，在未来的通信系统(如6G通信系统)中，应用功能可以仍是AF网元，或者也可以具有其它名称，本申请并不限定。
其中，数据网络，主要用于为终端设备提供数据传输服务。数据网络可以是私有网络，如局域网，也可以是公用数据网(public data network，PDN)网络，如因特网(Internet)，还可以是运营商共同部署的专有网络，如配置的IP多媒体网络子系统(IP multimedia core network subsystem，IMS)服务。
需要说明的，在本申请中，中间会话管理网元可单独部署，也可以集成在会话管理网元中，本申请不作限制。另外，源分流用户面网元和源用户面网元可以合一部署或者分离部署，当其为分离部署时，服务区域可以不同；目标分流用户面网元和目标用户面网元可以合一部署或者分离部署，当其为分离部署时，服务区域可以不同，本申请不作限制。
下面以5G通信系统为例，说明本申请实施例适用的一种具体可能的网络架构示意图。图2A为基于服务化架构的5G网络架构示意图。图2B所示的5G网络架构中可包括数据网络和运营商网络。下面对其中的部分网元的功能进行简单介绍说明。
其中，运营商网络可包括以下网元中的一个或多个：鉴权服务器功能(Authentication Server Function，AUSF)网元、网络开放功能(network exposure function，NEF)网元、策略控制功能(policy control function，PCF)网元、统一数据管理(unified data management，UDM)网元、统一数据库(Unified Data Repository，UDR)、网络存储功能(Network Repository Function，NRF)网元、AF网元、接入与移动性管理功能(access and mobility management function，AMF)网元、SMF网元、RAN设备以及UPF网元、网络切片选择功能(Network Slice  Selection Function，NSSF)网元(图2A或图2B中未示出)等。上述运营商网络中，除无线接入网设备之外的网元或设备可以称为核心网网元或核心网设备。
无线接入网设备可以是基站(base station)、演进型基站(evolved NodeB，eNodeB)、TRP、5G移动通信系统中的下一代基站(next generation NodeB，gNB)、6G移动通信系统中的下一代基站、未来移动通信系统中的基站或无线保真(wireless fidelity，WiFi)系统中的接入节点等；也可以是完成基站部分功能的模块或单元，例如，可以是CU，也可以是分布式单元(DU。无线接入网设备可以是宏基站，也可以是微基站或室内站，还可以是中继节点或施主节点等。本申请的实施例对无线接入网设备所采用的具体技术和具体设备形态不做限定。
与RAN通信的终端也可以称为终端设备、UE、移动台、移动终端等。终端可以广泛应用于各种场景，例如，设备到设备(device-to-device，D2D)、车物(vehicle to everything，V2X)通信、MTC、物联网(internet of things，IOT)、虚拟现实、增强现实、工业控制、自动驾驶、远程医疗、智能电网、智能家具、智能办公、智能穿戴、智能交通、智慧城市等。终端可以是手机、平板电脑、带无线收发功能的电脑、可穿戴设备、车辆、无人机、直升机、飞机、轮船、机器人、机械臂、智能家居设备等。本申请的实施例对终端所采用的具体技术和具体设备形态不做限定。
基站和终端可以是固定位置的，也可以是可移动的。基站和终端可以部署在陆地上，包括室内或室外、手持或车载；也可以部署在水面上；还可以部署在空中的飞机、气球和人造卫星上。本申请的实施例对基站和终端的应用场景不做限定。
AMF网元，执行移动性管理、接入鉴权/授权等功能。此外，还负责在终端与PCF间传递用户策略。
SMF网元，执行会话管理、PCF下发控制策略的执行、UPF的选择、终端的IP地址分配等功能。
UPF网元，作为和数据网络的接口UPF，完成用户面数据转发、基于会话/流级的计费统计，带宽限制等功能。
UDM网元，执行管理签约数据、用户接入授权等功能。
UDR，执行签约数据、策略数据、应用数据等类型数据的存取功能。
NEF网元，用于支持能力和事件的开放。
AF网元，传递应用侧对网络侧的需求，例如，QoS需求或用户状态事件订阅等。AF可以是第三方功能实体，也可以是运营商部署的应用服务，如IMS语音呼叫业务。
PCF网元，负责针对会话、业务流级别进行计费、QoS带宽保障及移动性管理、终端策略决策等策略控制功能。
NRF网元，可用于提供网元发现功能，基于其他网元的请求，提供网元类型对应的网元信息。NRF还提供网元管理服务，如网元注册、更新、去注册以及网元状态订阅和推送等。
AUSF网元，负责对用户进行鉴权，以确定是否允许用户或设备接入网络。
NSSF网元，用于选择网络切片，对网络切片内的用户进行计数等。
DN，是位于运营商网络之外的网络，运营商网络可以接入多个DN，DN上可部署多种业务，可为终端提供数据和/或语音等服务。例如，DN是某智能工厂的私有网络，智能工厂安装在车间的传感器可为终端，DN中部署了传感器的控制服务器，控制服务器可为传感器提供服务。传感器可与控制服务器通信，获取控制服务器的指令，根据指令将采集的传感器数据传送给控制服务器等。又例如，DN是某公司的内部办公网络，该公司员工的手机或者电脑可为终端， 员工的手机或者电脑可以访问公司内部办公网络上的信息、数据资源等。
图2A中Nausf、Nnef、Npcf、Nudm、Naf、Namf、Nsmf分别为上述AUSF、NEF、PCF、UDM、AF、AMF和SMF提供的服务化接口，用于调用相应的服务化操作。N1、N2、N3、N4，以及N6为接口序列号。这些接口序列号的含义可参见第三代合作伙伴计划(3rd generation partnership project，3GPP)标准协议中定义的含义，在此不做限制。
图2B为基于点对点接口的5G网络架构示意图，其中的网元的功能的介绍可以参考图2A中对应的网元的功能的介绍，不再赘述。图2B与图2A的主要区别在于：图2A中的各个控制面网元之间的接口是服务化的接口，图2B中的各个控制面网元之间的接口是点对点的接口。
在图2B所示的架构中，各个网元之间的接口名称及功能如下：
1)、N1：AMF与终端之间的接口，可以用于向终端传递QoS控制规则等。
2)、N2：AMF与RAN之间的接口，可以用于传递核心网侧至RAN的无线承载控制信息等。
3)、N3：RAN与UPF之间的接口，主要用于传递RAN与UPF间的上下行用户面数据。
4)、N4：SMF与UPF之间的接口，可以用于控制面与用户面之间传递信息，包括控制面向用户面的转发规则、QoS控制规则、流量统计规则等的下发以及用户面的信息上报。
5)、N5：AF与PCF之间的接口，可以用于应用业务请求下发以及网络事件上报。
6)、N6：UPF与DN的接口，用于传递UPF与DN之间的上下行用户数据流。
7)、N7：PCF与SMF之间的接口，可以用于下发协议数据单元(protocol data unit，PDU)会话粒度以及业务数据流粒度控制策略。
8)、N8：AMF与UDM间的接口，可以用于AMF向UDM获取接入与移动性管理相关签约数据与鉴权数据，以及AMF向UDM注册终端当前移动性管理相关信息等。
9)、N9：UPF和UPF之间的用户面接口，用于传递UPF间的上下行用户数据流。
10)、N10：SMF与UDM间的接口，可以用于SMF向UDM获取会话管理相关签约数据，以及SMF向UDM注册终端当前会话相关信息等。
11)、N11：SMF与AMF之间的接口，可以用于传递RAN和UPF之间的PDU会话隧道信息、传递发送给终端的控制消息、传递发送给RAN的无线资源控制信息等。
12)、N12：AMF和AUSF间的接口，可以用于AMF向AUSF发起鉴权流程，其中可携带用户隐藏标识(subscription concealed identifier,SUCI)作为签约标识；
13)、N13：UDM与AUSF间的接口，可以用于AUSF向UDM获取用户鉴权向量，以执行鉴权流程。
14)、N15：PCF与AMF之间的接口，可以用于下发终端策略及接入控制相关策略。
15)、N35：UDM与UDR间的接口，可以用于UDM从UDR中获取用户签约数据信息。
16)、N36：PCF与UDR间的接口，可以用于PCF从UDR中获取策略相关签约数据以及应用数据相关信息。
可以理解的是，上述网元或者功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。可选的，上述网元或者功能可以由一个设备实现，也可以由多个设备共同实现，还可以是一个设备内的一个功能模块，本申请实施例对此不作具体限定。
本申请中的会话管理网元、用户面网元、策略控制网元分别可以是图2A或图2B中的SMF、UPF、PCF，也可以是未来通信如6G网络中具有上述SMF、UPF、PCF的功能的网元，本申请对此不限定。在本申请的实施例中，以SMF、UPF、PCF分别作为会话管理网元、用户面网元、 策略控制网元的一个举例进行描述。
可以理解的是，上述网元或者功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。上述网元或者功能可划分出一个或多个服务，进一步，还可能会出现独立于网络功能存在的服务。在本申请中，上述功能的实例、或上述功能中包括的服务的实例、或独立于网络功能存在的服务实例均可称为服务实例。
此外，本申请实施例提供的技术方案可适用于多种系统架构。本申请实施例描述的网络架构以及业务场景是为了更加清楚的说明本申请实施例的技术方案，并不构成对于本申请实施例提供的技术方案的限定，本领域普通技术人员可知，随着网络架构的演变和新业务场景的出现，本申请实施例提供的技术方案对于类似的技术问题，同样适用。
可选的，图1中的各网元(例如中间会话管理网元、会话管理网元、用户面网元、接入网设备、终端设备、移动性管理网元、应用网元等)可以由一个设备实现，也可以由多个设备共同实现，还可以是一个设备内的一个功能模块，本申请实施例对此不作具体限定。可以理解的是，上述功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行的软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。
例如，图1中的各设备均可以通过图3中的通信装置300来实现。图3所示为可适用于本申请实施例提供的通信装置的硬件结构示意图。该通信装置300包括至少一个处理器301，通信线路302以及至少一个通信接口304。
处理器301可以是一个通用中央处理器(central processing unit，CPU)，微处理器，特定应用集成电路(application-specific integrated circuit，ASIC)，或一个或多个用于控制本申请方案程序执行的集成电路。
通信线路302可包括一通路，在上述组件之间传送信息。
通信接口304，是任何收发器一类的装置(如天线等)，用于与其他设备或通信网络通信，如以太网，RAN，无线局域网(wireless local area networks，WLAN)等。
可选的，通信装置300还包括存储器303，存储器303可以是只读存储器(read-only memory，ROM)或可存储静态信息和指令的其他类型的静态存储设备，随机存取存储器(random access memory，RAM)或者可存储信息和指令的其他类型的动态存储设备，也可以是电可擦可编程只读存储器(electrically erasable programmable read-only memory，EEPROM)、只读光盘(compact disc read-only memory，CD-ROM)或其他光盘存储、光碟存储(包括压缩光碟、激光碟、光碟、数字通用光碟、蓝光光碟等)、磁盘存储介质或者其他磁存储设备、或者能够用于携带或存储具有指令或数据结构形式的期望的程序代码并能够由计算机存取的任何其他介质，但不限于此。存储器可以是独立存在，通过通信线路302与处理器相连接。存储器也可以和处理器集成在一起。本申请实施例提供的存储器通常可以具有非易失性。其中，存储器303用于存储执行本申请方案的计算机执行指令，并由处理器301来控制执行。处理器301用于执行存储器303中存储的计算机执行指令，从而实现本申请下述实施例提供的方法。
可选的，本申请实施例中的计算机执行指令也可以称之为应用程序代码，本申请实施例对此不作具体限定。
在一种可能的实施方式中，处理器301可以包括一个或多个CPU，例如图3中的CPU0和CPU1。
在一种可能的实施方式中，通信装置300可以包括多个处理器，例如图3中的处理器301和处理器307。这些处理器中的每一个可以是一个单核(single-CPU)处理器，也可以是一个多核(multi-CPU)处理器。这里的处理器可以指一个或多个设备、电路、和/或用于处理数据(例如计算机程序指令)的处理核。
在一种可能的实施方式中，通信装置300还可以包括输出设备305和输入设备306。输出设备305和处理器301通信，可以以多种方式来显示信息。例如，输出设备305可以是液晶显示器(liquid crystal display，LCD)，发光二级管(light emitting diode，LED)显示设备，阴极射线管(cathode ray tube，CRT)显示设备，或投影仪(projector)等。输入设备306和处理器301通信，可以以多种方式接收用户的输入。例如，输入设备306可以是鼠标、键盘、触摸屏设备或传感设备等。
上述的通信装置300可以是一个通用设备或者是一个专用设备。在具体实现中，通信装置300可以是台式机、便携式电脑、网络服务器、掌上电脑、移动手机、平板电脑、无线终端设备、嵌入式设备或有图3中类似结构的设备。本申请实施例不限定通信装置300的类型。
以下结合附图，说明本申请实施例提供的技术方案。
参见图4，图4为本申请实施例提供的一种指示信息的传输方法的流程示意图。如图4所示，该方法包括但不限于以下步骤：
401.中间会话管理网元向会话管理网元发送第一指示信息，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。
相应的，会话管理网元从中间会话管理网元接收第一指示信息。
需要说明的，在本申请中，第一指示信息用于指示中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元。即中间会话管理网元已经根据终端设备的当前位置信息选择目标分流用户面网元和目标用户面网元，并分别和目标分流用户面网元和目标用户面网元建立了终端设备的数据包转发控制协议(packet forwarding control protocol,PFCP)会话。同时，中间会话管理网元需要等待会话管理网元的指示，以便删除和源分流用户面网元和源用户面网元的终端设备的PFCP会话。
可选的，第一指示信息可以包含在第一PDU会话更新请求消息中，第一PDU会话更新请求消息用于指示会话管理网元更新第一PDU会话。第一PDU会话更新请求消息还可以包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址。其中，第一PDU会话更新请求消息可以为Nsmf_PDUSession_Update request。
402.会话管理网元根据第一指示信息向中间会话管理网元发送第二指示信息，第二指示信息用于指示目标用户面网元缓存上行数据包。
相应的，中间会话管理网元从会话管理网元接收第二指示信息。
可选的，步骤402，可以理解为：会话管理网元可以根据第一指示信息获知中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，即会话管理网元可以根据第一指示信息获知本地用户面网元发生改变。而本地用户面网元的改变可能导致应用网元的切换，即本地用户面网元的改变可能导致源应用网元将切换至目标应用网元。为了避免目标用户面网元在目标应用网元完成切换前转发上行数据包，所以会话管理网元可以先向中间会话管理网元发送第二指示信息，使得目标用户面网元可以先缓存上行数据包。
可选的，第二指示信息可以为第一字段的取值，第一字段的取值可以为至少一个比特的 取值或枚举值，在此不做限制。其中，第一字段可以采用以下任意方式实现：
方式1.1、第一字段可以为第一PDU会话更新响应消息中的新增字段或原有字段。其中，第一PDU会话更新响应消息用于指示会话管理网元成功更新第一PDU会话，第一PDU会话更新响应消息可以为Nsmf_PDUSession_Update response。
方式1.2、第一字段可以为第一信息中的新增字段或原有字段。其中，第一信息用于指示建立中间会话管理网元与目标用户面网元的PFCP会话，第一信息可以为N4信息。可选的，第一信息可以包含在第一PDU会话更新响应消息中。
方式1.3、第一字段可以为第一信元中的字段。其中，第一信元为第五数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。第五数据包转发规则可以为目标用户面网元向数据网络转发来自目标分流用户面网元的数据包对应的规则。可选的，第五数据包转发规则可以包含在第一信息中。
示例性的，第一字段的取值为1时用于指示目标用户面网元缓存上行数据包，第一字段的取值为0时用于指示目标用户面网元不缓存上行数据包或无含义；或，第一字段的取值为0时用于指示目标用户面网元缓存上行数据包，第一字段的取值为1时用于指示目标用户面网元不缓存上行数据包或无含义，在此不做限制。
其中，针对方式1.3，第一字段的取值可以为第一信元中缓存比特的取值，缓存比特的取值可以为第一数值，第一数值可以0、1或其他数值，在此不做限制。
403.中间会话管理网元根据第二指示信息，向目标用户面网元发送第三指示信息，第三指示信息用于指示目标用户面网元缓存上行数据包。
相应的，目标用户面网元从中间会话管理网元接收第三指示信息。
可选的，针对步骤402中的方式1.2和方式1.3，第二指示信息和第三指示信息相同。即步骤403，可以替换为：中间会话管理网元向目标用户面网元发送第二指示信息，其中，第二指示信息可以包含在数据包转发控制协议会话更新请求消息(PFCP session modification request)中，数据包转发控制协议会话更新请求消息用于指示目标用户面网元更新终端设备的PFCP会话。
可选的，针对步骤402中的方式1.1，第三指示信息可以为第二字段的取值，第二字段的取值可以为至少一个比特的取值或枚举值，在此不做限制。第二字段可以为第二信元中的字段，第二信元为第五数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。换句话来说，针对步骤402中的方式1.1，中间会话管理网元可以从会话管理网元接收第五数据包转发规则，因此，中间会话管理网元可以根据第一指示信息，向目标用户面网元发送第五数据包转发规则，第五数据包转发规则可以包含在数据包转发控制协议会话更新请求消息中，数据包转发控制协议会话更新请求消息用于指示目标用户面网元更新终端设备的PFCP会话。
其中，第一信元可以与第二信元相同或不同，在此不做限制。
其中，第一字段可以与第二字段相同或不同，在此不做限制。
示例性的，第二字段的取值为1时用于指示目标用户面网元缓存上行数据包，第二字段的取值为0时用于指示目标用户面网元不缓存上行数据包或无含义；或，第二字段的取值为0时用于指示目标用户面网元缓存上行数据包，第二字段的取值为1时用于指示目标用户面网元不缓存上行数据包或无含义，在此不做限制。
404.会话管理网元向中间会话管理网元发送第四指示信息，第四指示信息用于指示目标用户面网元转发上行数据包，第四指示信息为会话管理网元获知目标应用网元已完成切换后 发送的指示信息。
相应的，中间会话管理网元从会话管理网元接收第四指示信息。
其中，第四指示信息为会话管理网元获知目标应用网元已完成切换后发送的指示信息，可以理解为：第四指示信息为会话管理网元从目标应用网元接收确认消息后发送的指示信息，确认消息用于指示目标应用网元已完成切换。
可选的，第四指示信息可以包含在第二PDU会话更新请求消息中，第二PDU会话更新请求消息用于指示中间会话管理网元更新第二PDU会话，第二PDU会话更新请求消息可以为Nsmf_PDUSession_Update request。
可选的，第四指示信息可以为第三字段的取值，第三字段的取值可以为至少一个比特的取值或枚举值，在此不做限制。其中，第三字段可以采用以下任意方式实现：
方式2.1、第三字段可以为第二PDU会话更新请求消息中的新增字段或原有字段。其中，第二PDU会话更新请求消息可以为Nsmf_PDUSession_Update request。
方式2.2、第三字段可以为第二信息中的新增字段或原有字段。其中，第二信息用于指示更新中间会话管理网元与目标用户面网元的PFCP会话，第二信息可以为N4信息。可选的，第二信息可以包含在第二PDU会话更新请求消息中。
方式2.3、第三字段可以为第三信元中的字段。其中，第三信元为第六数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。第六数据包转发规则可以为目标用户面网元向数据网络转发来自目标分流用户面网元的数据包对应的规则。可选的，第六数据包转发规则可以包含在第二信息中。
示例性的，第三字段的取值为1时用于指示目标用户面网元缓存上行数据包，第三字段的取值为0时用于指示目标用户面网元不缓存上行数据包或无含义；或，第三字段的取值为0时用于指示目标用户面网元缓存上行数据包，第三字段的取值为1时用于指示目标用户面网元不缓存上行数据包或无含义，在此不做限制。
其中，针对方式2.3，第三字段的取值可以为第三信元中缓存比特的取值，缓存比特的取值可以为第二数值，第二数值可以0、1或其他数值，在此不做限制。可以理解的，本申请中，第六数据包转发规则可以与第五数据包转发规则相同。
405.中间会话管理网元根据第四指示信息，向目标用户面网元发送第五指示信息，第五指示信息用于指示目标用户面网元转发上行数据包。
相应的，目标用户面网元从中间会话管理网元接收第五指示信息。
可选的，针对步骤404中的方式2.2和方式2.3，第四指示信息和第五指示信息相同。即步骤404，可以替换为：中间会话管理网元向目标用户面网元发送第四指示信息，其中，第四指示信息可以包含在数据包转发控制协议会话更新请求消息中，数据包转发控制协议会话更新请求消息用于指示目标用户面网元更新终端设备的PFCP会话。
可选的，针对步骤404中的方式2.1，第五指示信息可以为第四字段的取值，第四字段的取值可以为至少一个比特的取值或枚举值，在此不做限制。第四字段可以为第四信元中的字段，第四信元为第六数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。换句话来说，针对步骤404中的方式2.1，中间会话管理网元可以从会话管理网元接收第六数据包转发规则，因此，中间会话管理网元可以根据第四指示信息，向目标用户面网元发送第六数据包转发规则，第六数据包转发规则可以包含在数据包转发控制协议会话更新请求消息中，数据包转发控制协议会话更新请求消息用于指示目标用户面网元更新终端设备的PFCP会话。
其中，第三信元可以与第四信元相同或不同，在此不做限制。
其中，第三字段可以与第四字段相同或不同，在此不做限制。
示例性的，第四字段的取值为1时用于指示目标用户面网元缓存上行数据包，第四字段的取值为0时用于指示目标用户面网元不缓存上行数据包或无含义；或，第四字段的取值为0时用于指示目标用户面网元缓存上行数据包，第四字段的取值为1时用于指示目标用户面网元不缓存上行数据包或无含义，在此不做限制。
可以看出，上述技术方案中，中间会话管理网元向会话管理网元发送第一指示信息，使得会话管理网元可以获知中间会话管理网元已插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元，从而可以使得中间会话管理网元根据来自会话管理网元的第二指示信息向目标用户面网元发送第三指示信息，进而让目标用户面网元根据第三指示信息缓存上行数据包。同时，当会话管理网元获知目标应用网元已完成切换时，可以向中间会话管理网元发送第四指示信息，使得中间会话管理网元根据第四指示信息向目标用户面网元发送第五指示信息，进而让目标用户面网元根据第五指示信息转发上行数据包。可以理解的，由于目标用户面网元未在目标应用网元完成切换前转发上行数据包，而是在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。另外，由于目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的连续性和可靠性。
可选的，该方法还可以包括：中间会话管理网元向用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则。相应的，用户面网元从中间会话管理网元接收第一数据包转发控制协议请求消息。
其中，若用户面网元为源分流用户面网元，第一数据包检测规则为源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，第一数据包转发规则为源分流用户面网元向源用户面网元转发来自目标分流用户面网元的数据包对应的规则；若用户面网元为目标分流用户面网元，第一数据包检测规则为目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，第一数据包转发规则为目标分流用户面网元向源分流用户面网元转发来自目标接入网设备的数据包对应的规则。
可选的，第一数据包转发控制协议请求消息用于指示用户面网元建立或更新终端设备的PFCP会话。若用户面网元为源分流用户面网元，第一数据包转发控制协议请求消息用于指示源分流用户面网元更新终端设备的PFCP会话，第一数据包转发控制协议请求消息可以为数据包转发控制协议会话更新请求消息(PFCP session modification request)；若用户面网元为目标分流用户面网元，第一数据包转发控制协议请求消息用于指示目标分流用户面网元建立或更新终端设备的PFCP会话，第一数据包转发控制协议请求消息可以为数据包转发控制协议会话更新请求消息(PFCP session modification request)或者数据包转发控制协议会话更新请求消息(PFCP session establishmentrequest)。
可选的，用户面网元在接收第一数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第一数据包转发控制协议响应消息，第一数据包转发控制协议响应消息用于指示用户面网元成功建立或更新终端设备的PFCP会话。
示例性的，源分流用户面网元在接收第一数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第一数据包转发控制协议响应消息，第一数据包转发控制协议响应消息用于指示源分流用户面网元成功更新终端设备的PFCP会话，第一数据包转发控制协议响应消 息可以为数据包转发控制协议会话更新响应消息(PFCP session modification response)；目标分流用户面网元在接收第一数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第一数据包转发控制协议响应消息，第一数据包转发控制协议响应消息用于指示目标分流用户面网元成功建立或更新终端设备的PFCP会话，第一数据包转发控制协议响应消息可以为数据包转发控制协议会话更新响应消息(PFCP session modification response)或数据包转发控制协议会话建立响应消息(PFCP session establishmentresponse)。可以理解的，若第一数据包转发控制协议请求消息用于指示目标分流用户面网元建立终端设备的PFCP会话，第一数据包转发控制协议响应消息用于指示目标分流用户面网元成功建立终端设备的PFCP会话；若第一数据包转发控制协议请求消息用于指示目标分流用户面网元更新终端设备的PFCP会话，第一数据包转发控制协议响应消息用于指示目标分流用户面网元成功更新终端设备的PFCP会话。
可选的，第一数据包检测规则为上行数据包检测规则，第一数据包转发规则为上行数据包转发规则。
可选的，第一数据包转发控制协议请求消息中还可以包括第三数据包检测规则和第三数据包转发规则。若用户面网元为源分流用户面网元，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自远端用户面网元的数据包对应的规则；或，第三数据包检测规则为源分流用户面网元检测来自源用户面网元的数据包对应的规则，第三数据包转发规则为源分流用户面网元向目标分流用户面网元转发来自源用户面网元的数据包对应的规则。若用户面网元为目标分流用户面网元，第三数据包检测规则为目标分流用户面网元检测来自源分流用户面网元的数据包对应的规则，第三数据包转发规则为目标分流用户面网元向目标接入网设备转发来自源分流用户面网元的数据包对应的规则。
可选的，第三数据包检测规则为下行数据包检测规则，第三数据包转发规则为下行数据包转发规则。
可以看出，上述技术方案中，中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第一数据包转发控制协议请求消息，第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第一数据包检测规则检测数据包，并按照第一数据包转发规则转发数据包，避免了终端设备的上行数据包的丢失，提高了数据包传输的连续性和可靠性。
可选的，该方法还可以包括：中间会话管理网元从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息。相应的，会话管理网元向中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息。
可选的，在中间会话管理网元向用户面网元发送第一数据包转发控制协议请求消息之前，中间会话管理网元从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息。
其中，第二数据包检测规则为检测来自目标接入网设备的数据包的规则，第二数据包转发规则为将来自目标接入网设备的数据包转发至源分流用户面网元的规则；或，第二数据包检测规则为检测来自目标分流用户面网元的数据包的规则，第二数据包转发规则为将来自目标分流用户面网元的数据包转发至源用户面网元的规则。
可选的，第二数据包检测规则和第二数据包转发规则可以包含在第三信息中，第三信息可以为N4信息。可以理解的，第三信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；或，第三信息用于指示中间会话管理网元建立与目标分流用户面网 元之间的PFCP会话。如，若第二数据包检测规则为检测来自目标分流用户面网元的数据包的规则，第三信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第二数据包转发规则为将来自目标分流用户面网元的数据包转发至源用户面网元的规则，第三信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第二数据包检测规则为检测来自目标接入网设备的数据包的规则，第三信息用于指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话；若第二数据包转发规则为将来自目标接入网设备的数据包转发至源分流用户面网元的规则，第三信息用于指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话。另外，第三信息可以包含在第一PDU会话更新响应消息中。
可选的，第二数据包检测规则为上行数据包检测规则，第二数据包转发规则为上行数据包转发规则。
其中，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
示例性的，第六指示信息用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元转发数据包对应的规则。
又示例性的，第六指示信息用于指示以下一项或多项：第二数据包检测规则为目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为目标分流用户面网元转发数据包对应的规则。
可选的，第六指示信息可以为第五字段的取值，第五字段的取值可以为至少一个比特的取值或枚举值，在此不做限制。其中，第五字段可以采用以下任意方式实现：
方式3.1、第五字段可以为第一PDU会话更新请求消息中的新增字段或原有字段。
方式3.2、第五字段可以为第三信息中的新增字段或原有字段。
方式3.3、第五字段可以为第五信元中的字段。其中，第五信元为第二数据包检测规则或第二数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。
示例性的，第五字段的取值为1时用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元转发数据包对应的规则，第五字段的取值为0时用于指示以下一项或多项：第二数据包检测规则不是源分流用户面网元检测数据包对应的规则、第二数据包转发规则不是源分流用户面网元转发数据包对应的规则、无含义；或，第五字段的取值为0时用于指示以下一项或多项：第二数据包检测规则为源分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元转发数据包对应的规则，第五字段的取值为1时用于指示以下一项或多项：第二数据包检测规则不是源分流用户面网元检测数据包对应的规则、第二数据包转发规则不是源分流用户面网元转发数据包对应的规则、无含义，在此不做限制。
可选的，第六指示信息可以为转发隧道规则指示。
可以看出，上述技术方案中，中间会话管理网元可以从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息，使得中间会话管理网元可以获知以下一项或多项：第二数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第二数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到；若用户面网元为源分流用户面网元，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。
其中，目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址用于指示目标分流用户面网元接收上行业务数据包。源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址用于指示源分流用户面网元接收上行业务数据包。
其中，第六指示信息可以为“Y”。
示例性的，参见表1，表1所述的第二数据包检测规则和第二数据包转发规则为会话管理网元指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话的N4信息中包含。表1为数据包检测规则、数据包转发规则以及指示信息之间的对应关系。如表1所示，UL PDR259(第二数据包检测规则的标识)、源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址(源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址包含在第一数据包转发规则中)、Access(源接口)、N3(源接口类型)、ULFAR 259(第二数据包转发规则的标识)、Core(目标接口)、N9(目标接口类型)、第六指示信息之间存在对应关系。因为第六指示信息为“Y”，所以中间会话管理网元可以根据第六指示信息在第二数据包转发规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址，得到第一数据包转发规则。
表1：数据包检测规则、数据包转发规则以及指示信息之间的对应关系
Figure PCTCN2022125902-appb-000001
可以看出，上述技术方案中，由于第一数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第一数据包转发规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并 检测数据包，根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址和源分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失。同理，由于第一数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第一数据包转发规则中还包括源用户面网元的隧道端点标识和源用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据源用户面网元的隧道端点标识和源用户面网元的网际协议地址和源用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的上行数据包的丢失。
参见图5，图5为本申请实施例提供的一种消息传输方法的流程示意图。如图5所示，该方法包括但不限于以下步骤：
501.中间会话管理网元向用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则。
相应的，用户面网元从中间会话管理网元接收第三数据包转发控制协议请求消息。
其中，关于第三数据包检测规则和第三数据包转发规则，可以参考图4中步骤405相关描述，在此不加赘述。
可选的，第三数据包转发控制协议请求消息用于指示用户面网元建立或更新终端设备的PFCP会话。若用户面网元为源分流用户面网元，第三数据包转发控制协议请求消息用于指示源分流用户面网元更新终端设备的PFCP会话，第三数据包转发控制协议请求消息可以为数据包转发控制协议会话更新请求消息(PFCP session modification request)；若用户面网元为目标分流用户面网元，第三数据包转发控制协议请求消息用于指示目标分流用户面网元建立或更新终端设备的PFCP会话，第三数据包转发控制协议请求消息可以为数据包转发控制协议会话更新请求消息(PFCP session modification request)或数据包转发控制协议会话建立请求消息(PFCP session establishmentrequest)。
可选的，用户面网元在接收第三数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第三数据包转发控制协议响应消息，第三数据包转发控制协议响应消息用于指示用户面网元成功建立或更新终端设备的PFCP会话。
示例性的，源分流用户面网元在接收第三数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第三数据包转发控制协议响应消息，第三数据包转发控制协议响应消息用于指示源分流用户面网元成功更新终端设备的PFCP会话；目标分流用户面网元在接收第三数据包转发控制协议请求消息后，还可以向中间会话管理网元发送第三数据包转发控制协议响应消息，第三数据包转发控制协议响应消息用于指示目标分流用户面网元成功建立或更新终端设备的PFCP会话，第三数据包转发控制协议响应消息可以为数据包转发控制协议会话更新响应消息(PFCP session modification response)或转发控制协议会话建立响应消息(PFCP session establishmentresponse)。可以理解的，若第三数据包转发控制协议请求消息用于指示目标分流用户面网元建立终端设备的PFCP会话，第三数据包转发控制协议响应消息用于指示目标分流用户面网元成功建立终端设备的PFCP会话；若第三数据包转发控制协议请求消息用于指示目标分流用户面网元更新终端设备的PFCP会话，第三数据包转发控制协议响应消息用于指示目标分流用户面网元成功更新终端设备的PFCP会话。
可选的，第三数据包转发控制协议请求消息中还可以包括第一数据包检测规则和第一数 据包转发规则。
可选的，在本申请中，第一数据包转发控制协议请求消息可以与第三数据包转发控制协议请求消息为同一消息或不同消息，在此不做限制。若第一数据包转发控制协议请求消息与第三数据包转发控制协议请求消息为同一消息，第一数据包转发控制协议响应消息可以与第三数据包转发控制协议响应消息为同一消息，在此不做限制。
可以看出，上述技术方案中，中间会话管理网元可以向源分流用户面网元或目标分流用户面网元发送第三数据包转发控制协议请求消息，第三数据包转发控制协议请求消息中包括第三数据包检测规则和第三数据包转发规则，使得源分流用户面网元或目标分流用户面网元按照第三数据包检测规则检测数据包，并按照第三数据包转发规则转发数据包，避免了终端设备的下行数据包的丢失，提高了数据包传输的可靠性。
可选的，该方法还可以包括：中间会话管理网元从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息。相应的，会话管理网元向中间会话管理网元发送第四数据包检测规则、第四数据包转发规则和第七指示信息。
可选的，中间会话管理网元向用户面网元发送第三数据包转发控制协议请求消息之前，中间会话管理网元从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息。
可选的，第四数据包检测规则为检测来自源分流用户面网元的数据包的规则，第四数据包转发规则为将来自源分流用户面网元的数据包转发至目标接入网设备的规则；或，
第四数据包检测规则为检测来自远端用户面网元的数据包的规则，第四数据包转发规则为将来自远端用户面网元的数据包转发至目标分流用户面网元的规则；或，
第四数据包检测规则为检测来自源用户面网元的数据包的规则，第四数据包转发规则为将来自源用户面网元的数据包转发至目标分流用户面网元的规则。
可选的，第四数据包检测规则和第四数据包转发规则可以包含在第四信息中，第四信息可以为N4信息。可以理解的，第四信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；或，第四信息用于指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话。如，若第四数据包检测规则为检测来自远端用户面网元的数据包的规则，第四信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第四数据包转发规则为将来自远端用户面网元的数据包转发至目标分流用户面网元的规则，第四信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第四数据包检测规则为检测来自源用户面网元的数据包的规则，第四信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第四数据包转发规则为将来自源用户面网元的数据包转发至目标分流用户面网元的规则，第四信息用于指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话；若第四数据包检测规则为检测来自源分流用户面网元的数据包的规则，第四信息用于指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话；若第四数据包转发规则为将来自源分流用户面网元的数据包转发至目标接入网设备的规则，第四信息用于指示中间会话管理网元建立与目标分流用户面网元之间的PFCP会话。另外，第四信息可以包含在第一PDU会话更新响应消息中。
其中，第四数据包检测规则为下行数据包检测规则，第四数据包转发规则为下行数据包转发规则。
其中，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网 元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
示例性的，第七指示信息用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元转发数据包对应的规则。
又示例性的，第七指示信息用于指示以下一项或多项：第四数据包检测规则为目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为目标分流用户面网元转发数据包对应的规则。
可选的，第七指示信息可以为第六字段的取值，第六字段的取值可以为至少一个比特的取值或枚举值，在此不做限制。其中，第六字段可以采用以下任意方式实现：
方式4.1、第六字段可以为第一PDU会话更新请求消息中的新增字段或原有字段。
方式4.2、第六字段可以为第四信息中的新增字段或原有字段。
方式4.3、第六字段可以为第六信元中的字段。其中，第六信元为第四数据包检测规则或第四数据包转发规则中转发动作信元、或相似定义或功能的信元，或扩展字段的信元，在此不做限制。
示例性的，第六字段的取值为1时用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元转发数据包对应的规则，第六字段的取值为0时用于指示以下一项或多项：第四数据包检测规则不是源分流用户面网元检测数据包对应的规则、第四数据包转发规则不是源分流用户面网元转发数据包对应的规则、无含义；或，第六字段的取值为0时用于指示以下一项或多项：第四数据包检测规则为源分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元转发数据包对应的规则，第六字段的取值为1时用于指示以下一项或多项：第四数据包检测规则不是源分流用户面网元检测数据包对应的规则、第四数据包转发规则不是源分流用户面网元转发数据包对应的规则、无含义，在此不做限制。
可选的，第七指示信息可以为转发隧道规则指示。
其中，在本申请中，第六指示信息和第七指示信息可以相同。如，第六指示信息和第七指示信息均为“Y”。
示例性的，参见表2，表2为数据包检测规则、数据包转发规则以及指示信息之间的对应关系。如表2所示，表2所述的第四数据包检测规则和第四数据包转发规则为会话管理网元指示中间会话管理网元删除或更新与源分流用户面网元之间的PFCP会话的N4信息中包含。DL PDR 258(第四数据包检测规则的标识)、目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、Core(源接口)、N9(源接口类型)、DLFAR 258(第四数据包转发规则的标识)、Access(目标接口)、N3(目标接口类型)、第七指示信息之间存在对应关系。因为第七指示信息为“Y”，所以中间会话管理网元可以根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址。
表2：数据包检测规则、数据包转发规则以及指示信息之间的对应关系
Figure PCTCN2022125902-appb-000002
Figure PCTCN2022125902-appb-000003
可以看出，上述技术方案中，中间会话管理网元可以从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息，使得中间会话管理网元可以获知以下一项或多项：第四数据包检测规则为源分流用户面网元或目标分流用户面网元检测数据包对应的规则、第四数据包转发规则为源分流用户面网元或目标分流用户面网元转发数据包对应的规则。
可选的，若用户面网元为目标分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到；若用户面网元为源分流用户面网元，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
可以看出，上述技术方案中，由于第三数据包检测规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址，使得目标分流用户面网元可以根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址接收并检测数据包，根据目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址和目标接入网设备建立隧道，使得数据包可以通过隧道进行传输，避免了目标分流用户面网元与目标接入网设备之间的数据包的丢失。同理，由于第三数据包检测规则中还包括源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址、第三数据包转发规则中还包括目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址，使得源分流用户面网元可以根据源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址接收并检测数据包，根据目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址和目标分流用户面网元建立隧道，使得数据包可以通过隧道进行传输，避免了终端设备的下行数据包的丢失。
下面以中间会话管理网元根据源分流用户面网元和源接入网设备之间的N3接口确定建立与用户面网元(该用户面网元可以指目标用户面网元和/或目标分流用户面网元)之间的业务数据包转发隧道为例说明本方案。具体的，参见图6A，图6A为本申请实施例提供的又一种消息传输的流程示意图。如图6A所示，该方法包括但不限于以下步骤：
601.中间会话管理网元发送第一PFCP会话建立请求消息给目标用户面网元，PFCP会话建立请求消息用于通知目标用户面网元建立终端设备的PFCP会话。
相应的，目标用户面网元从中间会话管理网元接收第一PFCP会话建立请求消息。
其中，步骤601的第一PFCP会话建立请求消息中包含第一上行数据包检测规则和第一上行数据包转发规则，第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则和第一上行数据包转发规则用于目标用户面网元建立所有业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于目标用户面网元建立所有业务数据包的下行转发通道。可以理解的，上行业务数据包由目标用户面网元接收后转发到数据网络，下行业务数据包由目标用户面网元接收后转发到目标分流用户面网元。
602.目标用户面网元回复第一PFCP会话建立响应消息(PFCP session establishment response)给中间会话管理网元，第一PFCP会话建立响应消息指示第一PFCP会话成功建立。
相应的，中间会话管理网元从目标用户面网元接收第一PFCP会话建立响应消息。
其中，步骤602的PFCP会话建立响应消息中包含目标用户面网元分配的业务数据包转发信息，业务数据包转发信息包含目标用户面网元的隧道端点标识和目标用户面网元的网际协议地址,目标用户面网元的隧道端点标识和目标用户面网元的网际协议地址用于中间会话管理网元指示目标分流用户面网元建立上行业务数据包的转发通道。
可以理解的，图6A所示实施例中由中间会话管理网元决定并建立上行或下行业务数据包的转发隧道，用于确保在分流用户面网元和用户面网元同时改变的流程中的上行或者下行业务数据包的连续性。如中间会话管理网元根据源分流用户面网元和源接入网设备之间是否建立N3用户面隧道，确定是否需要建立上行或下行业务数据包的转发隧道。即，如果源分流用户面网元和源接入网设备之间建立了N3用户面隧道，则中间会话管理网元确定需要建立上行或下行业务数据包的转发隧道。
603.中间会话管理网元发送第二PFCP会话建立请求消息给目标分流用户面网元，PFCP会话建立请求消息用于通知目标分流用户面网元建立终端设备的PFCP会话。
相应的，目标分流用户面网元从中间会话管理网元接收第二PFCP会话建立请求消息。
其中，步骤603的第二PFCP会话建立请求消息中包含第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则和第一上行数据包转发规则用于目标分流用户面网元建立所有业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于目标分流用户面网元建立所有业务数据包的下行转发通道。可以理解的，上行业务数据包由目标接入网设备发到目标分流用户面网元后，再由目标分流用户面网元转发到远端用户面网元，下行业务数据包由远端用户面网元发到目标分流用户面网元后，再由目标分流用户面网元转发到目标接入网设备。
另外，步骤603的第二PFCP会话建立请求消息中还包含第二下行数据包检测规则和第二下行数据包转发规则，第二下行数据包检测规则和第二下行数据包转发规则用于目标分流用户面网元建立下行业务数据包的转发通道，以确保在分流用户面网元和用户面网元同时改变的流程中的下行业务数据包的连续性。下行业务数据包由源分流用户面网元发给目标分流用户面网元，再由目标分流用户面网元转发到目标接入网设备。可以理解的，步骤603的第二PFCP会话建立请求消息与图5中步骤501中间会话管理网元向目标分流用户面网元发送的第三PFCP请求消息为同一消息，步骤603的第二下行数据包检测规则与图5中步骤501中间会话管理网元向目标分流用户面网元发送的第三数据包检测规则相同，第二下行数据包转发规则与图5中步骤501中间会话管理网元向目标分流用户面网元发送的第三数据包转发规则相 同。
604.目标分流用户面网元回复第二PFCP会话建立响应消息给中间会话管理网元，第二PFCP会话建立响应消息用于指示第二PFCP会话成功建立。
相应的，中间会话管理网元从目标分流用户面网元接收第二PFCP会话建立响应消息。
其中，步骤604的第二PFCP会话建立响应消息中包含目标分流用户面网元分配的第一业务数据包转发信息，第二业务数据包转发信息和第三业务数据包转发信息。第一业务数据包转发信息，第二业务数据包转发信息和第三业务数据包转发信息均包含目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址。第一业务数据包转发信息用于中间会话管理网元指示目标接入网设备建立上行业务数据包的转发通道，第二业务数据包转发信息用于中间会话管理网元指示目标用户面网元或远端用户面网元建立下行业务数据包的转发通道，第三业务数据包转发信息用于中间会话管理网元指示源分流用户面网元建立为了保证下行业务数据包连续性的下行业务数据包的转发通道。
605.中间会话管理网元发送第一PFCP会话更新请求消息给源分流用户面网元，第一PFCP会话更新请求消息用于通知源分流用户面网元更新终端设备的第三PFCP会话。
相应的，源分流用户面网元从中间会话管理网元接收第一PFCP会话更新请求消息。
其中，步骤605的第一PFCP会话更新请求消息中包含第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则，第一上行数据包检测规则和第一上行数据包转发规则用于源分流用户面网元建立来自源用户面网元分流的业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于源分流用户面网元建立所有业务数据包的下行转发通道，以确保在分流用户面网元和用户面网元同时改变的流程中的上行或下行业务数据包的连续性。可以理解的，上行业务数据包由目标分流用户面网元发到源分流用户面网元后，再由源分流用户面网元转发到源用户面网元。下行业务数据包由远端用户面网元发到源分流用户面网元后或者由源用户面网元发到源分流用户面网元后，再由源分流用户面网元转发到目标分流用户面网元。可以理解的，步骤605的第一PFCP会话更新请求消息与图4中步骤405中间会话管理网元向源分流用户面网元发送的第一数据包转发控制协议请求消息为同一消息，步骤605的第一上行数据包检测规则与图4中步骤405中间会话管理网元向源分流用户面网元发送的第一数据包检测规则相同，第一上行数据包转发规则与图4中步骤405中间会话管理网元向源分流用户面网元发送的第一数据包转发规则相同。步骤605的第一PFCP会话更新请求消息与图5中步骤501中间会话管理网元向源分流用户面网元发送的第三数据包转发控制协议请求消息为同一消息，步骤605的第一下行数据包检测规则与图5中步骤501中间会话管理网元向源分流用户面网元发送的第三数据包检测规则相同，第一下行数据包转发规则与图5中步骤501中间会话管理网元向源分流用户面网元发送的第三数据包转发规则相同。
606.源分流用户面网元回复第一PFCP会话更新响应消息给中间会话管理网元，第一PFCP会话更新响应消息指示第三PFCP会话成功更新。
相应的，中间会话管理网元从源分流用户面网元接收第一PFCP会话更新响应消息。
其中，步骤606的第一PFCP会话更新响应消息中包含源分流用户面网元分配的业务数据包转发信息，业务数据包转发信息包含源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址。业务数据包转发信息用于中间会话管理网元指示目标分流用户面网元建立为了保证上行业务数据包连续性的上行业务数据包的转发通道。
在步骤606后，下行业务数据包转发路径：
远端用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
源用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
可选的，在步骤606之后，本方案还可以包括但不限于以下步骤607-步骤616，具体的，参见图6B，图6B为本申请实施例提供的又一种消息传输方法的流程示意图。
607.中间会话管理网元发送第一PDU会话更新请求(Nsmf_PDUSession_Update request)给会话管理网元,第一PDU会话更新请求消息中包含第一指示信息以及步骤604中目标分流用户面网元分配的第二业务数据包转发信息。
相应的，会话管理网元从中间会话管理网元接收第一PDU会话更新请求。
其中，关于第一指示信息，可以参考图4中步骤401相关描述，在此不加赘述。
608.会话管理网元回复第一PDU会话更新响应消息(Nsmf_PDUSession_Update response)给中间会话管理网元，第一PDU会话更新响应消息中包含第一N4信息，第二N4信息，第三N4信息和第四N4信息。
相应的，中间会话管理网元从会话管理网元接收第一PDU会话更新响应消息。
其中，第一N4信息用于指示中间会话管理网元建立中间会话管理网元与目标分流用户面网元的PFCP会话，第一N4信息中包含第三上行数据包检测规则、第三上行数据包转发规则、第三下行数据包检测规则和第三下行数据包转发规则。第三上行数据包检测规则和第三上行数据包转发规则用于指示目标分流用户面网元建立从目标用户面网元分流的业务数据包的上行转发通道，第三下行数据包检测规则和第三下行数据包转发规则用于指示目标分流用户面网元建立从目标用户面网元分流的业务数据包的下行转发通道。上行业务数据包由目标接入网设备发到目标分流用户面网元后，再由目标分流用户面网元转发到目标用户面网元，下行业务数据包由目标用户面网元发到目标分流用户面网元后，再由目标分流用户面网元转发到目标接入网设备。比如，针对应用标识为100的业务对应的业务数据包，从目标用户面网元分流，则第一N4信息中包含该业务对应的上行数据包检测规则和上行数据包转发规则，或，第一N4信息中包含该业务对应的下行数据包检测规则和下行数据包转发规则。
其中，第二N4信息用于指示中间会话管理网元建立中间会话管理网元与目标用户面网元的PFCP会话，第二N4信息中包含第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则。第二上行数据包检测规则和第二上行数据包转发规则用于指示目标用户面网元建立从目标用户面网元分流的业务数据包的上行转发通道，第二下行数据包检测规则和第二下行数据包转发规则用于指示目标用户面网元建立从目标用户面网元分流的业务数据包的下行转发通道。可以理解的，上行业务数据包由目标分流用户面网元发送到目标用户面网元后，再由目标用户面网元转发到数据网络，下行业务数据包由数据网络发送到目标用户面网元后，再由目标用户面网元转发到目标分流用户面网元。
其中，第三N4信息用于指示中间会话管理网元删除中间会话管理网元与源分流用户面网元的PFCP会话。
其中，第四N4信息用于指示中间会话管理网元删除中间会话管理网元与源用户面网元的PFCP会话。
另外，本地用户面网元的改变可能导致应用网元的切换，会话管理网元可以通知源应用网元目标用户面网元的接入点标识(DN Access Identifier,DNAI)，以便源应用网元根据接入点标识触发应用网元的切换。如果应用网元订阅会话管理网元的事件时，指示需要应用网元确认，即应用网元执行切换并向会话管理网元发送正向确认后，才能将上行数据包发送给 新的应用网元。换句话来说，当源应用网元切换至目标应用网元时，目标应用网元可以向会话管理网元发送正向确认，在这种情况下，目标用户面网元才能将上行数据包发送给目标应用网元。因此，为了实现该过程，步骤608的第一PDU会话更新响应消息中还包含第二指示信息。关于第二指示信息，可以参考图4中步骤402相关描述，在此不加赘述。
示例性的，第二指示信息可以通过以下任意一种情况实现：
情况1.1：会话管理网元可以在步骤608的第一PDU会话更新响应消息中通过一个比特或者枚举指示目标用户面网元缓存上行数据包，如在新的参数或者原有的参数中通过一个比特来指示，其中，该比特设为1表示目标用户面网元缓存上行数据包，该比特设为0表示目标用户面网元不需要缓存上行数据包或者转发上行数据包或者没有特殊含义；或者该比特设为0表示目标用户面网元缓存上行数据包，该比特设为1表示目标用户面网元不需要缓存上行数据包或者转发上行数据包或者没有特殊含义；或者新的参数或者原有的参数中通过枚举来指示，通过一个特定的枚举值表示目标用户面网元缓存上行数据包；
或者，情况1.2：会话管理网元也可以在第二N4信息中，通过一个比特或者枚举指示目标用户面网元缓存上行数据包，具体的指示方式可以参考上述情况1.1的指示方式，在此不加赘述；
或者，情况1.3：会话管理网元可以将第二N4信息中包含的第二上行数据包转发规则中包含的转发动作信元中的缓存比特设置为1来指示目标用户面网元缓存上行数据包。
609.会话管理网元发送第二PFCP会话更新请求消息给远端用户面网元，第二PFCP会话更新请求消息用于通知远端用户面网元更新终端设备的PFCP会话。
相应的，远端用户面网元从会话管理网元接收第二PFCP会话更新请求消息。
其中，步骤609的第二PFCP会话更新请求消息中包含步骤607中的目标分流用户面网元分配的第二业务数据包转发信息，远端用户面网元从数据网络收到下行业务数据包后，根据目标分流用户面网元分配的第二业务数据包转发信息，将下行业务数据包发往目标分流用户面网元。
610.远端用户面网元回复第二PFCP会话更新响应消息给会话管理网元，第二PFCP会话更新响应消息指示第四PFCP会话成功更新。
相应的，会话管理网元从远端用户面网元接收PFCP会话更新响应消息。
在步骤610后，下行业务数据包转发路径：
远端用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
源用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
611.中间会话管理网元发送第三PFCP会话更新请求消息给目标分流用户面网元，第三PFCP会话更新请求消息用于通知目标分流用户面网元更新终端设备的PFCP会话。
相应的，目标分流用户面网元从中间会话管理网元接收第三PFCP会话更新请求消息。
其中，步骤611的第三PFCP会话更新请求消息中包含步骤608的第一N4信息中所包含第三上行数据包检测规则、第三上行数据包转发规则、第三下行数据包检测规则和第三下行数据包转发规则。
另外，步骤611的第三PFCP会话更新请求消息中还包含第二上行数据包检测规则和第二上行数据包转发规则，第二上行数据包检测规则和第二上行数据包转发规则用于目标分流用户面网元建立从源用户面网元分流的业务数据包的上行转发通道，以确保在分流用户面网元和用户面网元同时改变的流程中的上行业务数据包的连续性。上行业务数据包由目标接入网设备发给目标分流用户面网元，再由目标分流用户面网元转发到源分流用户面网元。可以理 解的，步骤611的第三PFCP会话更新请求消息与图4中步骤405中间会话管理网元向目标分流用户面网元发送的第一数据包转发控制协议请求消息为同一消息，步骤611的第二上行数据包检测规则与图4中步骤405中间会话管理网元向目标分流用户面网元发送的第一数据包检测规则相同，第二上行数据包转发规则与图4中步骤405中间会话管理网元向目标分流用户面网元发送的第一数据包转发规则相同。
612.目标分流用户面网元回复第三PFCP会话更新响应消息给中间会话管理网元，第三PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从目标分流用户面网元接收第三PFCP会话更新响应消息。
613.中间会话管理网元发送第四PFCP会话更新请求消息给目标用户面网元，第四PFCP会话更新请求消息用于通知目标用户面网元更新终端设备的PFCP会话。
相应的，目标用户面网元从中间会话管理网元接收第四PFCP会话更新请求消息。
其中，步骤613的第四PFCP会话更新请求消息中包含步骤608的第二N4信息中所包含第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则。
另外，步骤613的第四PFCP会话更新请求消息中还包含第三指示信息，关于第三指示信息，可以参考图4中步骤403相关描述，在此不加赘述。
示例性的，针对步骤608中的情况1.2和情况1.3，中间会话管理网元将第三指示信息转发给目标用户面网元；针对步骤608中的情况1.1，中间会话管理网元根据收到的第二指示信息，将发送给目标用户面网元的第二上行数据包转发规则中的包含的转发动作信元中的缓存比特设置为1来指示目标用户面网元缓存上行数据包。
614.目标用户面网元回复第四PFCP会话更新响应消息给中间会话管理网元，第四PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从目标用户面网元接收第四PFCP会话更新响应消息。
在步骤614后，下行业务数据包转发路径：
远端用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
目标用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
615.中间会话管理网元发送PDU会话资源更新请求消息给目标接入网设备，PDU会话资源更新请求消息中包含步骤604中的第一业务数据包转发信息。
相应的，目标接入网设备从中间会话管理网元接收PDU会话资源更新请求消息。
616.目标接入网设备回复PDU会话资源更新响应消息给中间会话管理网元，PDU会话资源更新响应消息指示PDU会话资源更新成功。
相应的，中间会话管理网元从目标接入网设备接收PDU会话资源更新响应消息。
在步骤616后，上行业务数据包转发路径：
终端设备->目标接入网设备->目标分流用户面网元->源分流用户面网元->源用户面网元；
终端设备->目标接入网设备->目标分流用户面网元->远端用户面网元。
可选的，在步骤616之后，本方案还可以包括但不限于以下步骤617-步骤624，具体的，参见图6C，图6C为本申请实施例提供的又一种消息传输方法的流程示意图。
617.会话管理网元等待目标应用网元的确认消息。
618.会话管理网元从目标应用网元接收确认消息后，会话管理网元发送第二PDU会话更新消息(Nsmf_PDUSession_Update request)给中间会话管理网元，第二PDU会话更新消息中包含第四指示信息。
相应的，目标应用网元向会话管理网元发送确认消息。
其中，关于第四指示信息，可以参考图4中步骤404相关描述，在此不加赘述。
示例性的，第四指示信息可以通过以下任意一种情况实现：
情况2.1：会话管理网元可以在消息中通过一个比特或者枚举指示目标用户面网元转发上行数据包，如在新的参数或者原有的参数中通过一个比特来指示，其中，该比特设为1表示目标用户面网元转发上行数据包，该比特设为0表示目标用户面网元不需要转发上行数据包或者缓存上行数据包或者没有特殊含义；或者该比特设为0表示目标用户面网元转发上行数据包，该比特设为1表示目标用户面网元不需要转发上行数据包或者缓存上行数据包或者没有特殊含义；或者新的参数或者原有的参数中通过枚举来指示，通过一个特定的枚举值表示目标用户面网元转发上行数据包。
或者，情况2.2：会话管理网元也可以在消息中包含第五N4信息，第五N4信息用于指示更新中间会话管理网元与目标用户面网元的PFCP会话，在第五N4信息中通过一个比特或者枚举指示目标用户面网元转发上行数据包，具体的指示方式可以参考上述情况2.1的指示方式，在此不加赘述。
或者，情况2.3：会话管理网元可以在第五N4信息中包含上行数据包转发规则，并将上行数据包转发规则中包含的转发动作信元中的转发比特设置为1来指示转发上行数据包。这里的上行数据包转发规则，即为步骤608的第二N4信息中的第二上行数据包转发规则。
619.中间会话管理网元回复第二PDU会话更新响应消息给会话管理网元(Nsmf_PDUSession_Update response)，第二PDU会话更新响应消息指示第二PDU会话更新成功。
相应的，会话管理网元从中间会话管理网元接收第二PDU会话更新响应消息。
620.中间会话管理网元发送第五PFCP会话更新请求消息给目标用户面网元，第五PFCP会话更新请求消息用户通知目标用户面网元更新终端设备的PFCP会话。
相应的，目标用户面网元从中间会话管理网元接收第五PFCP会话更新请求消息。
其中，步骤620的第五PFCP会话更新请求消息中包含第五指示信息，关于第五指示信息可以参考图4中步骤405相关描述，在此不加赘述。具体的，针对步骤618中的情况2.2和情况2.3，中间会话管理网元将第四指示信息转发给目标用户面网元；针对步骤618中的情况2.1，中间会话管理网元根据第四指示信息，将发送给目标用户面网元的第二上行数据包转发规则中的包含的转发动作信元中的转发比特设置为1来指示转发上行数据包。换句话来说，中间会话管理网元根据第四指示信息向目标用户面网元发送第五指示信息。
621.目标用户面网元回复第五PFCP会话更新响应消息，第五PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从目标用户面网元接收第五PFCP会话更新响应消息。
在步骤621后，上行业务数据包转发路径：
终端设备->目标接入网设备->目标分流用户面网元->目标用户面网元；
终端设备->目标接入网设备->目标分流用户面网元->远端用户面网元。
622.源分流用户面网元在预设时间内没有转发业务数据包时，则发送PFCP会话报告给中间会话管理网元，PFCP会话报告用于向中间会话管理网元通知此事件，即，PFCP会话报告用于通知源分流用户面网元在预设时间内没有转发业务数据包。
相应的，中间会话管理网元从源分流用户面网元接收PFCP会话报告。
623.中间会话管理网元根据PFCP会话报告，发起源测会话的删除，发送PFCP会话删除 消息给源用户面网元。
624.中间会话管理网元发送PFCP会话删除消息给源分流用户面网元。
可以看出，上述技术方案中，由于目标用户面网元未在目标应用网元完成切换前转发上行数据包，而是在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。另外，由于目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。同时，避免了终端设备的上行和下行数据包的丢失，提高了数据包传输的连续性和可靠性。
下面以会话管理网元确定建立与用户面网元(该用户面网元可以指目标用户面网元和/或目标分流用户面网元)之间的业务数据包转发隧道为例说明本方案。具体的，参见图7A，图7A为本申请实施例提供的又一种消息传输方法的流程示意图。如图7A所示，该方法包括但不限于以下步骤：
701.中间会话管理网元发送第一PFCP会话建立请求消息给目标用户面网元，第一PFCP会话建立请求消息用于通知目标用户面网元建立终端设备的PFCP会话。
相应的，目标用户面网元从中间会话管理网元接收第一PFCP会话建立请求消息。
其中，步骤701的第一PFCP会话建立请求消息中包含第一上行数据包检测规则和第一上行数据包转发规则，第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则和第一上行数据包转发规则用于目标用户面网元建立所有业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于目标用户面网元建立所有业务数据包的下行转发通道。可以理解的，上行业务数据包由目标用户面网元接收后转发到数据网络，下行业务数据包由目标用户面网元接收后转发到目标分流用户面网元。
702.目标用户面网元回复第一PFCP会话建立响应消息给中间会话管理网元，第一PFCP会话建立响应消息指示PFCP会话成功建立。
相应的，中间会话管理网元从目标用户面网元接收第一PFCP会话建立响应消息。
其中，步骤702的PFCP会话建立响应消息中包含目标用户面网元分配的业务数据包转发信息，业务数据包转发信息包含目标用户面网元的隧道端点标识和目标用户面网元的网际协议地址,目标用户面网元的隧道端点标识和目标用户面网元的网际协议地址用于中间会话管理网元指示目标接入网设备建立上行业务数据包的转发通道。
703.中间会话管理网元发送第二PFCP会话建立请求消息给目标分流用户面网元，第二PFCP会话建立请求消息用于通知目标分流用户面网元建立终端设备的PFCP会话。
相应的，目标分流用户面网元从中间会话管理网元接收第二PFCP会话建立请求消息。
其中，步骤703的第二PFCP会话建立请求消息中包含第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则和第一上行数据包转发规则用于目标分流用户面网元建立所有业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于目标分流用户面网元建立所有业务数据包的下行转发通道。可以理解的，上行业务数据包由目标接入网设备发到目标分流用户面网元后，再由目标分流用户面网元转发到远端用户面网元，下行业务数据包由远端用户面网元发到目标分流用户面网元后，再由目标分流用户面网元转发到目标接入网设备。
704.目标分流用户面网元回复第二PFCP会话建立响应消息给中间会话管理网元，第二PFCP会话建立响应消息用于指示PFCP会话成功建立。
相应的，中间会话管理网元从目标分流用户面网元接收第二PFCP会话建立响应消息。
其中，步骤704的第二PFCP会话建立响应消息中包含目标分流用户面网元分配的第一业务数据包转发信息，第二业务数据包转发信息和第三业务数据包转发信息。第一业务数据包转发信息，第二业务数据包转发信息和第三业务数据包转发信息均包含目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址。第一业务数据包转发信息用于中间会话管理网元指示目标接入网设备建立上行业务数据包的转发通道，第二业务数据包转发信息用于中间会话管理网元指示目标用户面网元/远端用户面网元建立下行业务数据包的转发通道，第三业务数据包转发信息用于中间会话管理网元指示源分流用户面网元建立为了保证下行业务数据包连续性的下行业务数据包的转发通道。
705.中间会话管理网元发送第一PDU会话更新请求(Nsmf_PDUSession_Update request)给会话管理网元,第一PDU会话更新请求消息中包含第一指示信息以及步骤704中目标分流用户面网元分配的第二业务数据包转发信息。
相应的，会话管理网元从中间会话管理网元接收第一PDU会话更新请求。
其中，关于第一指示信息，可以参考图4中步骤401相关描述，在此不加赘述。
其中，图7A所示实施例由会话管理网元决定并建立上行或下行业务数据包的转发隧道，用于确保在分流用户面网元和用户面网元同时改变的流程中的上行或者下行业务数据包的连续性。可以理解的，会话管理网元可以针对所有会话都建立上行或下行业务数据包的转发隧道，或者针对特定会话建立上行或下行业务数据包的转发隧道。
706.会话管理网元回复第一PDU会话更新响应消息(Nsmf_PDUSession_Updateresponse)给中间会话管理网元，第一PDU会话更新响应消息中包含第一N4信息，第二N4信息，第三N4信息和第四N4信息。
相应的，中间会话管理网元从会话管理网元接收第一PDU会话更新响应消息。
其中，第一N4信息用于指示中间会话管理网元建立中间会话管理网元与目标分流用户面网元的PFCP会话，第一N4信息中包含第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则。第二上行数据包检测规则和第二上行数据包转发规则用于指示目标分流用户面网元建立从目标用户面网元分流的业务数据包的上行转发通道，第二下行数据包检测规则和第二下行数据包转发规则用于指示目标分流用户面网元建立从目标用户面网元分流的业务数据包的下行转发通道。上行业务数据包由目标接入网设备发到目标分流用户面网元后，再由目标分流用户面网元转发到目标用户面网元，下行业务数据包由目标用户面网元发到目标分流用户面网元后，再由目标分流用户面网元转发到目标接入网设备。比如，针对应用标识为100的业务对应的业务数据包，从目标用户面网元分流，则第一N4信息中包含该业务对应的上行数据包检测规则和上行数据包转发规则，或，第一N4信息中包含该业务对应的下行数据包检测规则和下行数据包转发规则。
另外，第一N4信息中还包括第三上行数据包检测规则、第三上行数据包转发规则、第三下行数据包检测规则和第三下行数据包转发规则。第三上行数据包检测规则和第三上行数据包转发规则用于目标分流用户面网元建立从源用户面网元分流的业务数据包的上行转发通道，第三下行数据包检测规则和第三下行数据包转发规则用于目标分流用户面网元建立所有业务数据包的下行转发通道，以确保在分流用户面网元和用户面网元同时改变的流程中的上行或下行业务数据包的连续性。其中，上行业务数据包由目标接入网设备发到目标分流用户面网元后，再由目标分流用户面网元转发到源分流用户面网元。下行业务数据包由源分流用户面网元发到目标分流用户面网元后，再由目标分流用户面网元转发到目标接入网设备。可以理解，第一N4信息中包括的第三上行数据包检测规则与图4中步骤405中间会话管理网元从会 话管理网元接收的第二数据包检测规则相同，第一N4信息中包括的第三上行数据包转发规则与图4中步骤405中间会话管理网元从会话管理网元接收的第二数据包转发规则相同。第一N4信息中包括的第三下行数据包检测规则与图5中步骤501中间会话管理网元从会话管理网元接收的第四数据包检测规则相同，第一N4信息中包括的第三下行数据包转发规则与图5中步骤501中间会话管理网元从会话管理网元接收的第四数据包转发规则相同。其中，第二数据包检测规则为目标分流用户面网元检测数据包对应的规则，第二数据包转发规则为目标分流用户面网元转发数据包对应的规则，第四数据包检测规则为目标分流用户面网元检测数据包对应的规则，第四数据包转发规则为目标分流用户面网元转发数据包对应的规则。
其中，第一N4信息中还包含转发隧道规则指示，用于指示上述第三上行数据包检测规则和第三上行数据包转发规则为确保在分流用户面网元和用户面网元同时改变的流程中的上行业务数据包的连续性所需要建立的数据包转发隧道对应的规则，第三下行数据包检测规则和第三下行数据包转发规则为确保在分流用户面网元和用户面网元同时改变的流程中的下行业务数据包的连续性所需要建立的数据包转发隧道对应的规则。可以理解的，第一N4信息中所包含的转发隧道规则指示包括上述第六指示信息和上述第七指示信息。
示例性的，第一N4信息中所包含的转发隧道规则指示可以通过以下任意一种情况实现：
情况3.1：会话管理网元可以在第一PDU会话更新响应消息中通过一个比特或者枚举指示转发隧道规则，如在新的参数或者原有的参数中通过一个比特来指示，其中该比特设为1表示转发隧道规则，该比特设为0表示不是转发隧道规则或者没有特殊含义；或者该比特设为0表示转发隧道规则，该比特设为1表示不是转发隧道规则或者没有特殊含义；或者新的参数或者原有的参数中通过枚举来指示，通过一个特定的枚举值表示转发隧道规则。
或者，情况3.2：会话管理网元也可以在第一N4信息、第三上行数据包检测规则、第三上行数据包转发规则、第三下行数据包检测规则或第三下行数据包转发规则中通过一个比特或者枚举指示转发隧道规则，转发隧道规则指示具体的指示方式可以参考情况3.1，在此不加赘述。
其中，第二N4信息用于指示中间会话管理网元建立中间会话管理网元与目标用户面网元的PFCP会话，第二N4信息中包含第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则。第二上行数据包检测规则和第二上行数据包转发规则用于指示目标用户面网元建立从目标用户面网元分流的业务数据包的上行转发通道，第二下行数据包检测规则和第二下行数据包转发规则用于指示目标用户面网元建立从目标用户面网元分流的业务数据包的下行转发通道。可以理解的，上行业务数据包由目标分流用户面网元发送到目标用户面网元后，再由目标用户面网元转发到数据网络，下行业务数据包由数据网络发送到目标用户面网元后，再由目标用户面网元转发到目标分流用户面网元。
其中，第三N4信息用于指示中间会话管理网元删除中间会话管理网元与源分流用户面网元的PFCP会话；
或，第三N4信息用于指示更新中间会话管理网元与源分流用户面网元的PFCP会话，第三N4信息中包含第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则和第一上行数据包转发规则用于源分流用户面网元建立从源用户面网元分流的业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于源分流用户面网元建立所有业务数据包的下行转发通道，进而确保在分流用户面网元和用户面网元同时改变的流程中的上行或者下行业务数据包的连续性。可以理解，第三N4信息中包括的第一上行数据包检测规则与图4中步骤405中 间会话管理网元从会话管理网元接收的第二数据包检测规则相同，第三N4信息中包括的第一上行数据包转发规则与图4中步骤405中间会话管理网元从会话管理网元接收的第二数据包转发规则相同。第三N4信息中包括的第一下行数据包检测规则与图5中步骤501中间会话管理网元从会话管理网元接收的第四数据包检测规则相同，第三N4信息中包括的第一下行数据包转发规则与图5中步骤501中间会话管理网元从会话管理网元接收的第四数据包转发规则相同。其中，第二数据包检测规则为源分流用户面网元检测数据包对应的规则，第二数据包转发规则为源分流用户面网元转发数据包对应的规则，第四数据包检测规则为源分流用户面网元检测数据包对应的规则，第四数据包转发规则为源分流用户面网元转发数据包对应的规则。
其中，第三N4信息还包含转发隧道规则指示，转发隧道规则指示用于指示上述第一上行数据包检测规则和第一上行数据包转发规则为确保在分流用户面网元和用户面网元同时改变的流程中的上行业务数据包的连续性所需要建立的数据包转发隧道对应的规则，第一下行数据包检测规则和第一下行数据包转发规则为确保在分流用户面网元和用户面网元同时改变的流程中的下行业务数据包的连续性所需要建立的数据包转发隧道对应的规则。转发隧道规则指示具体指示的方式可以参考第一N4信息中转发隧道规则指示的指示方式，在此不加赘述。
其中，第四N4信息用于指示中间会话管理网元删除中间会话管理网元与源用户面网元的PFCP会话。
另外，本地用户面网元的改变可能导致应用网元的切换，会话管理网元可以通知源应用网元目标用户面网元的接入点标识，以便源应用网元根据接入点标识触发应用网元的切换。如果应用网元订阅会话管理网元的事件时，指示需要应用网元确认，即应用网元执行切换并向会话管理网元发送正向确认后，才能将上行数据包发送给新的应用网元。换句话来说，当源应用网元切换至目标应用网元时，目标应用网元可以向会话管理网元发送正向确认，在这种情况下，目标用户面网元才能将上行数据包发送给目标应用网元。因此，为了实现该过程，步骤706的第一PDU会话更新响应消息中还包含第二指示信息。关于第二指示信息，可以参考图4中步骤402相关描述，在此不加赘述。
示例性的，第二指示信息可以通过以下任意一种情况实现：
情况4.1：会话管理网元可以在步骤706的第一PDU会话更新响应消息中通过一个比特或者枚举指示目标用户面网元缓存上行数据包，如在新的参数或者原有的参数中通过一个比特来指示，其中，该比特设为1表示目标用户面网元缓存上行数据包，该比特设为0表示目标用户面网元不需要缓存上行数据包或者转发上行数据包或者没有特殊含义；或者该比特设为0表示目标用户面网元缓存上行数据包，该比特设为1表示目标用户面网元不需要缓存上行数据包或者转发上行数据包或者没有特殊含义；或者新的参数或者原有的参数中通过枚举来指示，通过一个特定的枚举值表示目标用户面网元缓存上行数据包；
或者，情况4.2：会话管理网元也可以在第二N4信息中，通过一个比特或者枚举指示目标用户面网元缓存上行数据包，具体的指示方式可以参考上述情况1.1的指示方式，在此不加赘述；
或者，情况4.3：会话管理网元可以将第二N4信息中包含的第二上行数据包转发规则中包含的转发动作信元中的缓存比特设置为1来指示目标用户面网元缓存上行数据包。
可选的，在步骤706之后，本方案还可以包括但不限于以下步骤707-步骤716，具体的，参见图7B，图7B为本申请实施例提供的又一种消息传输方法的流程示意图。
707.中间会话管理网元发送第一PFCP会话更新请求消息给源分流用户面网元，第一PFCP 会话更新请求消息用于通知源分流用户面网元更新终端设备的PFCP会话。
相应的，源分流用户面网元从中间会话管理网元接收第一PFCP会话更新请求消息。
其中，步骤707的第一PFCP会话更新请求消息中包含第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则。第一上行数据包检测规则、第一上行数据包转发规则用于源分流用户面网元建立从源用户面网元分流的业务数据包的上行转发通道，第一下行数据包检测规则和第一下行数据包转发规则用于源分流用户面网元建立所有业务数据包的下行转发通道，以确保在分流用户面网元和用户面网元同时改变的流程中的上行或下行业务数据包的连续性。可以理解的，上行业务数据包由目标分流用户面网元发到源分流用户面网元后，再由源分流用户面网元转发到源用户面网元。下行业务数据包由远端用户面网元发到源分流用户面网元后或者由源用户面网元发到源分流用户面网元后，再由源分流用户面网元转发到目标分流用户面网元。
在一种实施方式中，步骤707中的第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则为中间会话管理网元根据步骤706的第三N4信息中的转发隧道规则指示确定第一上行数据包检测规则和第一上行数据包转发规则，第一下行数据包检测规则和第一下行数据包转发规则为确保在分流用户面功能和用户面功能同时改变的流程中的上行或下行业务数据包的连续性，需要建立数据包转发隧道后，步骤707中的第一上行数据包检测规则为中间会话管理网元在步骤706的第三N4信息中的第一上行数据包检测规则添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，步骤707中的第一上行数据包转发规则为中间会话管理网元根据步骤706的第三N4信息中的转发隧道规则指示在步骤706的第三N4信息中的第一上行数据包转发规则添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到，步骤707中的第一下行数据包检测规则为中间会话管理网元根据步骤706的第三N4信息中的转发隧道规则指示在步骤706的第三N4信息中的第一下行数据包检测规则添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，步骤707中的第一下行数据包转发规则为中间会话管理网元根据步骤706的第三N4信息中的转发隧道规则指示在步骤706的第三N4信息中的第一下行数据包转发规则添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
在另一种实现方式中，若在第三N4信息用于指示删除中间会话管理网元与源分流用户面网元的PFCP会话，中间会话管理功能根据步骤706第一N4信息中的转发隧道规则指示确定需要建立数据包转发隧道，确保在分流用户面功能和用户面功能同时改变的流程中的上行或下行业务数据包的连续性。则步骤707中的第一上行数据包检测规则、第一上行数据包转发规则、第一下行数据包检测规则和第一下行数据包转发规则为中间会话管理网元生成。
可以理解，步骤707中的第一上行数据包检测规则与图4中步骤405中间会话管理网元发送给源分流用户面网元的第一数据包检测规则相同，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。步骤707中的第一上行数据包转发规则与图4中步骤405中间会话管理网元发送给源分流用户面网元的第一数据包转发规则相同，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源用户面网元的隧道端点标识和源用户面网元的网际协议地址得到。步骤707中的第一下行数据包检测规则与图5中步骤501中间会话管理网元发送给源分流用户面网元的第三数据包检测规则相同，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加源 分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。步骤707中的第一下行数据包转发规则与图4中步骤405中间会话管理网元发送给源分流用户面网元的第三数据包转发规则相同，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。
708.源分流用户面网元回复第一PFCP会话更新响应消息给中间会话管理网元，第一PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从源分流用户面网元接收第一PFCP会话更新响应消息。
其中，步骤708的第一PFCP会话更新响应消息中包含源分流用户面网元分配的业务数据包转发信息，该业务数据包转发信息包含源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址。业务数据包转发信息用于目标分流用户面网元建立为了保证上行业务数据包连续性的上行业务数据包的转发通道。
709.中间会话管理网元发送第二PFCP会话更新请求消息给目标分流用户面网元，第二PFCP会话更新请求消息用于通知目标分流用户面网元更新终端设备的PFCP会话。
相应的，目标分流用户面网元从中间会话管理网元接收第二PFCP会话更新请求消息。
其中，步骤709的第二PFCP会话更新请求消息中包含步骤706的第一N4信息中包含的第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则、第二下行数据包转发规则、第三上行数据包检测规则、第三上行数据包转发规则、第三下行数据包检测规则和第三下行数据包转发规则。
需要说明的，中间会话管理网元根据步骤708中第一N4信息中的第三上行数据包检测规则和第三上行数据包转发规则，第三下行数据包检测规则和第三下行数据包转发规则关联的转发隧道规则指示，确定所述第三上行数据包检测规则和第三上行数据包转发规则，第三下行数据包检测规则和第三下行数据包转发规则为确保在分流用户面功能和用户面功能同时改变的流程中的上行或下行业务数据包的连续性，需要建立数据包转发隧道后，步骤709中的第三上行数据包检测规则为中间会话管理网元根据步骤706的第一N4信息中的转发隧道规则指示在步骤706的第一N4信息中的第三上行数据包检测规则添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，步骤709中的第三上行数据包转发规则为中间会话管理网元根据步骤706的第一N4信息中的转发隧道规则指示在步骤706的第一N4信息中的第三上行数据包转发规则添加源分流用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到，步骤709中的第一下行数据包检测规则为中间会话管理网元根据步骤706的第一N4信息中的转发隧道规则指示在步骤706的第一N4信息中的第一下行数据包检测规则添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到，步骤709中的第一下行数据包转发规则为中间会话管理网元根据步骤706的第一N4信息中的转发隧道规则指示在步骤706的第一N4信息中的第一下行数据包转发规则添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
可以理解，步骤709中的第三上行数据包检测规则与图4中步骤405中间会话管理网元发送给目标分流用户面网元的第一数据包检测规则相同，第一数据包检测规则为中间会话管理网元根据第六指示信息在第二数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。步骤709中的第三上行数据包转发规则与图4中步骤405中间会话管理网元发送给目标分流用户面网元的第一数据包转发规则相同，第一数据包转发规则为中间会话管理网元根据第六指示信息在第二数据包转发规则中添加源分流 用户面网元的隧道端点标识和源分流用户面网元的网际协议地址得到。步骤707中的第三下行数据包检测规则与图5中步骤501中间会话管理网元发送给目标分流用户面网元的第三数据包检测规则相同，第三数据包检测规则为中间会话管理网元根据第七指示信息在第四数据包检测规则中添加目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址得到。步骤707中的第三下行数据包转发规则与图4中步骤405中间会话管理网元发送给目标分流用户面网元的第三数据包转发规则相同，第三数据包转发规则为中间会话管理网元根据第七指示信息在第四数据包转发规则中添加目标接入网设备的隧道端点标识和目标接入网设备的网际协议地址得到。
示例性的，下面结合表3说明转发隧道规则指示的作用，参见表3，表3为数据包检测规则、数据包转发规则以及转发隧道规则指示之间的对应关系。
表3：数据包检测规则、数据包转发规则以及转发隧道规则指示之间的对应关系
Figure PCTCN2022125902-appb-000004
Figure PCTCN2022125902-appb-000005
如表3所示，PDR中的业务数据包转发信息和FAR中的业务数据包转发信息是需要中间会话管理网元包含到发送给源分流用户面网元/目标分流用户面网元的第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则、第三上行数据包检测规则和第三上行数据包转发规则，第三下行数据包检测规则和第三下行数据包转发规则中。目标分流用户面网元等网元针对确保在分流用户面网元和用户面网元同时改变的流程中的上行或下行业务数据包的连续性所建立的数据包转发隧道分配的业务数据包转发信息，与正常业务数据包转发分配的业务数据包转发信息不同，中间会话管理网元需要根据转发隧道规则指示区分上述两种情况的规则，并添加对应的业务数据包转发信息。如表3所示，DL PDR 258(第三下行数据包检测规则的标识)、目标分流用户面网元分配的第四业务数据包转发信息、Core(源接口)、N9(源接口类型)、DL FAR 258(第三下行数据包转发规则的标识)、目标接入网设备分配的第一业务数据包转发信息、Access(目标接口)、N3(目标接口类型)、转发隧道规则指示(Y)之间存在对应关系。因为转发隧道规则指示为Y，即表明第三下行数据包检测规则、第三下行数据包转发规则等为保障下行业务数据包的连续性所建立的数据包转发隧道分配的业务数据包转发信息。同理，UL PDR 259(第三上行数据包检测规则的标识)、目标分流用户面网元分配的第三业务数据包转发信息、Access(源接口)、N3(源接口类型)、UL FAR 259(第三上行数据包转发规则的标识)、源分流用户面网元分配的业务数据包转发信息、Core(目标接口)、N9(目标接口类型)、转发隧道规则指示(Y)之间存在对应关系。因为转发隧道规则指示为Y，即表明第三上行数据包检测规则、第三上行数据包转发规则等为保障上行业务数据包的连续性所建立的数据包转发隧道分配的业务数据包转发信息。
另外，DL PDR 256(第二下行数据包检测规则的标识)、目标分流用户面网元分配的第二业务数据包转发信息、Core(源接口)、N9(源接口类型)、DL FAR 256(第二下行数据包转发规则的标识)、目标接入网设备分配的第二业务数据包转发信息、Access(目标接口)、N3(目标接口类型)、转发隧道规则指示(N)之间存在对应关系。因为转发隧道规则指示为N，即表明第二下行数据包检测规则、第二下行数据包转发规则等为正常业务数据包转发分配的业务数据包转发信息。同理，UL PDR 257(第二上行数据包检测规则的标识)、目标分流用户面网元分配的第一业务数据包转发信息、Access(源接口)、N3(源接口类型)、UL FAR 257(第二上行数据包转发规则的标识)、目标用户面网元分配的业务数据包转发信息、Core(目 标接口)、N9(目标接口类型)、转发隧道规则指示(N)之间存在对应关系。因为转发隧道规则指示为N，即表明第二上行数据包检测规则、第二上行数据包转发规则等为正常业务数据包转发分配的业务数据包转发信息。710.目标分流用户面网元回复第二PFCP会话更新响应消息给中间会话管理网元，第二PFCP会话更新响应消息用于指示PFCP会话成功更新。
相应的，中间会话管理网元从目标分流用户面网元接收第二PFCP会话更新响应消息。
其中，步骤710的第二PFCP会话更新响应消息中包含目标分流用户面网元分配的第三业务数据包转发信息和第四业务数据包转发信息。第三业务数据包转发信息和第四业务数据包转发信息均包含目标分流用户面网元的隧道端点标识和目标分流用户面网元的网际协议地址。可以理解的，第三业务数据包转发信息用于源接入网设备建立为了保证上行业务数据包连续性的上行业务数据包的转发通道，第四业务数据包转发信息用于源分流用户面网元建立为了保证下行业务数据包连续性的下行业务数据包的转发通道。
在步骤710后，下行业务数据包转发路径：
远端用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
源用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
711.会话管理网元发送第三PFCP会话更新请求消息给远端用户面网元，第三PFCP会话更新请求消息用于通知远端用户面网元更新终端设备的PFCP会话。
相应的，远端用户面网元从会话管理网元接收第三PFCP会话更新请求消息。
其中，步骤711的第三PFCP会话更新请求消息中包含步骤705中的目标分流用户面网元分配的第二业务数据包转发信息，用于远端用户面网元从数据网络收到下行业务数据包后，根据目标分流用户面网元分配的第二业务数据包转发信息，发往目标分流用户面网元。
712.远端用户面网元回复第三PFCP会话更新响应消息给会话管理网元，第三PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，会话管理网元从远端用户面网元接收第三PFCP会话更新响应消息。
在步骤712后，下行业务数据包转发路径：
远端用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
源用户面网元->源分流用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
713.中间会话管理网元发送第四PFCP会话更新请求消息给目标用户面网元，第四PFCP会话更新请求消息用于通知目标用户面网元更新终端设备的PFCP会话。
相应的，目标用户面网元从中间会话管理网元接收第四PFCP会话更新请求消息。
其中，步骤713的第四PFCP会话更新请求消息中包含步骤706的第二N4信息中所包含第二上行数据包检测规则、第二上行数据包转发规则、第二下行数据包检测规则和第二下行数据包转发规则。
其中，步骤713的第四PFCP会话更新请求消息中还包含第三指示信息，关于第三指示信息，可以参考图4中步骤403相关描述，在此不加赘述。
示例性的，针对步706中的情况1.2和情况1.3，中间会话管理网元将第三指示信息转发给目标用户面网元；针对步骤706中的情况1.1，中间会话管理网元根据收到的第二指示信息，将发送给目标用户面网元的第二上行数据包转发规则中的包含的转发动作信元中的缓存比特设置为1来指示目标用户面网元缓存上行数据包。
714.目标用户面网元回复第四PFCP会话更新响应消息给中间会话管理网元，第四PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从目标用户面网元接收第四PFCP会话更新响应消息。
在步骤714后，下行业务数据包转发路径：
远端用户面网元->目标分流用户面网元->目标接入网设备->终端设备；
目标用户面网元->目标分流用户面网元->目标接入网设备->终端设备。
715.中间会话管理网元发送PDU会话资源更新请求消息给目标接入网设备，PDU会话资源更新请求消息中包含步骤704中的第一业务数据包转发信息。
相应的，目标接入网设备从中间会话管理网元接收PDU会话资源更新请求消息。
716.目标接入网设备回复PDU会话资源更新响应消息给中间会话管理网元，PDU会话资源更新响应消息指示PDU会话资源更新成功。
相应的，中间会话管理网元从目标接入网设备接收PDU会话资源更新响应消息。
在步骤716后，上行业务数据包转发路径：
终端设备->目标接入网设备->目标分流用户面网元->源分流用户面网元->源用户面网元；
终端设备->目标接入网设备->目标分流用户面网元->远端用户面网元。
可选的，在步骤716之后，本方案还可以包括但不限于以下步骤717-步骤724，具体的，参见图7C，图7C为本申请实施例提供的又一种消息传输方法的流程示意图。
717.会话管理网元等待目标应用网元的确认消息。
718.会话管理网元从目标应用网元接收确认消息后，会话管理网元发送第二PDU会话更新消息(Nsmf_PDUSession_Update request)给中间会话管理网元，第二PDU会话更新消息中包含第四指示信息。
其中，步骤718与图6C中步骤618相同，在此不加赘述。
719.中间会话管理网元回复第二PDU会话更新响应消息给会话管理网元(Nsmf_PDUSession_Update response)，第二PDU会话更新响应消息指示第二PDU会话更新成功。
相应的，会话管理网元从中间会话管理网元接收第二PDU会话更新响应消息。
720.中间会话管理网元发送第五PFCP会话更新请求消息给目标用户面网元，第五PFCP会话更新请求消息用户通知目标用户面网元更新终端设备的PFCP会话。
其中，步骤720与图6C中步骤620相同，在此不加赘述。
721.目标用户面网元回复第五PFCP会话更新响应消息，第五PFCP会话更新响应消息指示PFCP会话成功更新。
相应的，中间会话管理网元从目标用户面网元接收第五PFCP会话更新响应消息。
在步骤712后，上行业务数据包转发路径：
终端设备->目标接入网设备->目标分流用户面网元->目标用户面网元；
终端设备->目标接入网设备->目标分流用户面网元->远端用户面网元。
722.源分流用户面网元在预设时间内没有转发业务数据包时，则发送PFCP会话报告给中间会话管理网元，PFCP会话报告用于通知中间会话管理网元此事件，即，PFCP会话报告用于通知源分流用户面网元在预设时间内没有转发业务数据包。
相应的，中间会话管理网元从源分流用户面网元接收PFCP会话报告。
723.中间会话管理网元根据PFCP会话报告，发起源测会话的删除，发送PFCP会话删除消息给源用户面网元。
724.中间会话管理网元发送PFCP会话删除消息给源分流用户面网元。
可以看出，上述技术方案中，由于目标用户面网元未在目标应用网元完成切换前转发上 行数据包，而是在目标应用网元完成切换前缓存上行数据包，使得上行数据包未被转发出去，避免了上行数据包的丢失。另外，由于目标用户面网元在目标应用网元完成切换后才转发上行数据包，使得上行数据包可以转发至目标应用网元，提高了数据包传输的可靠性。同时，避免了终端设备的上行或下行数据包的丢失，提高了数据包传输的连续性和可靠性。
本申请还提供一种通信系统，该通信系统包括中间会话管理网元、会话管理网元和目标用户面网元，其中，中间会话管理网元，用于实现图4中由中间会话管理网元执行的动作；会话管理网元，用于实现图4中由会话管理网元执行的动作；目标用户面网元，用于实现图4中由目标用户面网元执行的动作。其次，该通信系统还包括用户面网元，该用户面网元包括源分流用户面网元和/或目标分流用户面网元，中间会话管理网元，用于实现图6A-图7C中由中间会话管理网元执行的动作；会话管理网元，用于实现图6A-图7C中由会话管理网元执行的动作；目标用户面网元，用于实现图6A-图7C中由目标用户面网元执行的动作；源分流用户面网元，用于实现图6A-图7C中由源分流用户面网元执行的动作；目标分流用户面网元，用于实现图6A-图7C中由目标分流用户面网元执行的动作。另外，该通信系统还包括目标接入网设备、源用户面网元和远端用户面网元，目标接入网设备，用于实现图6A-图7C中由目标接入网设备执行的动作；源用户面网元，用于实现图6A-图7C中由源用户面网元执行的动作；远端用户面网元，用于实现图6A-图7C中由远端用户面网元执行的动作。
本申请还提供又一种通信系统，该通信系统包括中间会话管理网元和用户面网元，该用户面网元包括源分流用户面网元和/或目标分流用户面网元，其中，中间会话管理网元，用于实现图5-图7C中由中间会话管理网元执行的动作；源分流用户面网元，用于实现图5-图7C中由源分流用户面网元执行的动作；目标分流用户面网元，用于实现图5-图7C中由目标分流用户面网元执行的动作。其次，该通信系统还包括会话管理网元和目标用户网元，会话管理网元，用于实现图6A-图7C中由会话管理网元执行的动作；目标用户面网元，用于实现图6A-图7C中由目标用户面网元执行的动作。另外，该通信系统还包括目标接入网设备、源用户面网元和远端用户面网元，目标接入网设备，用于实现图6A-图7C中由目标接入网设备执行的动作；源用户面网元，用于实现图6A-图7C中由源用户面网元执行的动作；远端用户面网元，用于实现图6A-图7C中由远端用户面网元执行的动作。
上述主要从各个网元之间交互的角度对本申请提供的方案进行了介绍。可以理解的是，上述实现各网元为了实现上述功能，其包含了执行各个功能相应的硬件结构和/或软件模块。本领域技术人员应该很容易意识到，结合本文中所公开的实施例描述的各示例的单元及算法步骤，本申请能够以硬件或硬件和计算机软件的结合形式来实现。某个功能究竟以硬件还是计算机软件驱动硬件的方式来执行，取决于技术方案的特定应用和设计约束条件。专业技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能，但是这种实现不应认为超出本申请的范围。
本申请实施例可以根据上述方法示例对中间会话管理网元、用户面网元(如源分流用户面网元、目标分流用户面网元、目标用户面网元等)、会话管理网元进行功能模块的划分，例如，可以对应各个功能划分各个功能模块，也可以将两个或两个以上的功能集成在一个处理模块中，上述集成的模块既可以采用硬件的形式实现，也可以采用软件功能模块的形式实现。需要说明的是，本申请实施例中对模块的划分是示意性的，仅仅为一种逻辑功能划分，实际实现时可以有另外的划分方式。
在采用集成的单元的情况下，参见图8，图8为本申请实施例提供的一种通信装置的结构示意图。该通信装置800可应用于上述图4-图7C所示的方法中，如图8所示，该通信装置800包括：收发模块801。收发模块801可以是收发器或者通信接口。该通信装置可用于实现上述任一方法实施例中涉及中间会话管理网元、用户面网元(如源分流用户面网元、目标分流用户面网元、目标用户面网元等)或会话管理网元，或用于实现上述任一方法实施例中涉及网元的功能。该网元或者网络功能既可以是硬件设备中的网络元件，也可以是在专用硬件上运行的软件功能，或者是平台(例如，云平台)上实例化的虚拟化功能。可选的，该通信装置800还可以包括处理模块802和存储模块803，处理模块802可以是一个或多个处理器，处理模块802可用于支持通信装置800执行上述方法实施例中的处理动作。存储模块803用于存储通信装置800的程序代码和数据。
一种实例，当该通信装置作为中间会话管理网元或为应用于中间会话管理网元中的芯片，并执行上述方法实施例中由中间会话管理网元执行的步骤。收发模块801用于支持与会话管理网元、用户面网元(如源分流用户面网元、目标分流用户面网元、目标用户面网元等)等之间的通信，收发模块具体执行图4-图7C中由中间会话管理网元执行的发送和/或接收的动作，例如支持中间会话管理网元执行步骤401和步骤403中的一个或多个步骤，和/或用于本文中所描述的技术的其他过程。
一种实例，当该通信装置作为会话管理网元或为应用于会话管理网元中的芯片，并执行上述方法实施例中由会话管理网元执行的步骤。收发模块801用于支持与中间会话管理网元等之间的通信，收发模块具体执行图4-图7C中由会话管理网元执行的发送和/或接收的动作，例如支持会话管理网元执行步骤402和步骤404中的一个或多个步骤，和/或用于本文中所描述的技术的其他过程。
一种实例，当该通信装置作为源分流用户面网元或为应用于源分流用户面网元中的芯片，并执行上述方法实施例中由源分流用户面网元执行的步骤。收发模块801用于支持与中间会话管理网元等之间的通信，收发模块具体执行图4-图7C中由源分流用户面网元执行的发送和/或接收的动作，例如支持源分流用户面网元执行步骤604和步骤616中的一个或多个步骤，和/或用于本文中所描述的技术的其他过程。
一种实例，当该通信装置作为目标分流用户面网元或为应用于目标分流用户面网元中的芯片，并执行上述方法实施例中由目标分流用户面网元执行的步骤。收发模块801用于支持与中间会话管理网元等之间的通信，收发模块具体执行图4-图7C中由目标分流用户面网元执行的发送和/或接收的动作，例如支持目标分流用户面网元执行步骤602和步骤610中的一个或多个步骤，和/或用于本文中所描述的技术的其他过程。
一种实例，当该通信装置作为目标用户面网元或为应用于目标用户面网元中的芯片，并执行上述方法实施例中由目标用户面网元执行的步骤。收发模块801用于支持与中间会话管理网元等之间的通信，收发模块具体执行图4-图7C中由目标用户面网元执行的发送和/或接收的动作，例如支持目标用户面网元执行本文中所描述的技术的其他过程。
在一种可能的实施方式中，当中间会话管理网元、源分流用户面网元、目标分流用户面网元、目标用户面网元或会话管理网元为芯片时，收发模块801可以是接口、管脚或电路等。接口可用于输入待处理的数据至处理器，并可以向外输出处理器的处理结果。具体实现中，接口可以是通用输入输出(general purpose input output，GPIO)接口，可以和多个外围设备(如显示器(LCD)、摄像头(camara)、射频(radio frequency，RF)模块、天线等等) 连接。接口通过总线与处理器相连。当然，接口也可以理解为通信接口。
处理模块802可以是处理器，该处理器可以执行存储模块存储的计算机执行指令，以使该芯片执行上述实施例涉及的方法。
进一步的，处理器可以包括控制器、运算器和寄存器。示例性的，控制器主要负责指令译码，并为指令对应的操作发出控制信号。运算器主要负责执行定点或浮点算数运算操作、移位操作以及逻辑操作等，也可以执行地址运算和转换。寄存器主要负责保存指令执行过程中临时存放的寄存器操作数和中间操作结果等。具体实现中，处理器的硬件架构可以是专用集成电路架构、无互锁管道阶段架构的微处理器(microprocessor without interlocked piped stages architecture，MIPS)架构、进阶精简指令集机器(advanced RISC machines，ARM)架构或者网络处理器(network processor，NP)架构等等。处理器可以是单核的，也可以是多核的。
该存储模块803可以为该芯片内的存储模块，如寄存器、缓存等。存储模块803也可以是位于芯片外部的存储模块，如ROM或可存储静态信息和指令的其他类型的静态存储设备，RAM等。
需要说明的，处理器、接口各自对应的功能既可以通过硬件设计实现，也可以通过软件设计来实现，还可以通过软硬件结合的方式来实现，这里不作限制。
本申请实施例还提供一种通信装置，包括处理器、存储器、输入接口和输出接口，输入接口用于接收来自通信装置之外的其它通信装置的信息，输出接口用于向通信装置之外的其它通信装置输出信息，处理器调用存储器中存储的计算机程序实现如图4-图8所示任一实施例。
本申请实施例还提供一种计算机可读存储介质，计算机可读存储介质中存储有计算机程序，当计算机程序被运行时，实现如图4-图8所示任一实施例。
本申请实施例还提供一种芯片，芯片包括至少一个处理器和接口，处理器用于读取并执行存储器中存储的指令，当指令被运行时，使得芯片执行如图4-图8所示任一实施例。
本申请实施例还提供一种包含指令的计算机程序产品，当其在计算机上执行时，使得图4-图8所示任一实施例被执行。
上述作为分离部件说明的单元可以是或者也可以不是物理上分开的，作为单元显示的部件可以是或者也可以不是物理单元，即可以位于一个地方，或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本申请实施例方案的目标。另外，在本申请各个实施例中的各网元单元可以集成在一个处理单元中，也可以是各个单元单独物理存在，也可以是两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现，也可以采用软件网元单元的形式实现。
上述集成的单元如果以软件网元单元的形式实现并作为独立的产品销售或使用时，可以存储在一个计算机可读取存储介质中。基于这样的理解，本申请的技术方案本质上做出贡献的部分，或者该技术方案的全部或部分可以以软件产品的形式体现出来，该计算机软件产品存储在一个存储介质中，包括若干指令用以使得一台计算机设备(可以是个人计算机，云服务器，或者网络设备等)执行本申请各个实施例上述方法的全部或部分步骤。而前述的存储介质包括：U盘、移动硬盘、只读存储器(ROM，Read-Only Memory)、随机存取存储器(RAM，Random Access Memory)、磁碟或者光盘等各种可以存储程序代码的介质。以上所述，仅为本申请的具体实施方式，但本申请的保护范围并不局限于此，任何熟悉本技术领域的技术人员 在本申请揭露的技术范围内，可轻易想到各种等效的修改或替换，这些修改或替换都应涵盖在本申请的保护范围之内。因此，本申请的保护范围应以权利要求的保护范围为准。

Claims (27)

  1. 一种指示信息的传输方法，其特征在于，所述方法应用于中间会话管理网元，所述方法包括：
    向会话管理网元发送第一指示信息，所述第一指示信息用于指示所述中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元；
    从会话管理网元接收第二指示信息，所述第二指示信息用于指示所述目标用户面网元缓存上行数据包；
    根据所述第二指示信息，向所述目标用户面网元发送第三指示信息，所述第三指示信息用于指示所述目标用户面网元缓存上行数据包；
    从所述会话管理网元接收第四指示信息，所述第四指示信息用于指示所述目标用户面网元转发所述上行数据包；
    根据所述第四指示信息，向所述目标用户面网元发送第五指示信息，所述第五指示信息用于指示所述目标用户面网元转发所述上行数据包。
  2. 根据权利要求1所述的方法，其特征在于，所述方法还包括：
    向用户面网元发送第一数据包转发控制协议请求消息，所述第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则；
    若所述用户面网元为所述源分流用户面网元，所述第一数据包检测规则为所述源分流用户面网元检测来自所述目标分流用户面网元的数据包对应的规则，所述第一数据包转发规则为所述源分流用户面网元向所述源用户面网元转发来自所述目标分流用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第一数据包检测规则为所述目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，所述第一数据包转发规则为所述目标分流用户面网元向所述源分流用户面网元转发来自所述目标接入网设备的数据包对应的规则。
  3. 根据权利要求1或2所述的方法，其特征在于，所述方法还包括：
    从会话管理网元接收第二数据包检测规则、第二数据包转发规则和第六指示信息；所述第六指示信息用于指示以下一项或多项：所述第二数据包检测规则为所述源分流用户面网元或所述目标分流用户面网元检测数据包对应的规则、所述第二数据包转发规则为所述源分流用户面网元或所述目标分流用户面网元转发数据包对应的规则。
  4. 根据权利要求2或3所述的方法，其特征在于，
    若所述用户面网元为所述目标分流用户面网元，所述第一数据包检测规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包检测规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到，所述第一数据包转发规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包转发规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到；
    若所述用户面网元为所述源分流用户面网元，所述第一数据包检测规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包检测规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到，所述第一数据包转发规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包转发规则中添加所述源用户面网元的隧道端点标识和所述源用户面网元的网际协议地址得到。
  5. 一种消息传输方法，其特征在于，所述方法应用于中间会话管理网元，所述方法包括：
    向用户面网元发送第三数据包转发控制协议请求消息，所述第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第三数据包检测规则为所述源分流用户面网元检测来自远端用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述远端用户面网元的数据包对应的规则；或，所述第三数据包检测规则为所述源分流用户面网元检测来自源用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述源用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述目标分流用户面网元检测来自所述源分流用户面网元的数据包对应的规则，所述第三数据包转发规则为所述目标分流用户面网元向目标接入网设备转发来自所述源分流用户面网元的数据包对应的规则。
  6. 根据权利要求5所述的方法，其特征在于，所述方法还包括：
    从会话管理网元接收第四数据包检测规则、第四数据包转发规则和第七指示信息；
    所述第七指示信息用于指示以下一项或多项：所述第四数据包检测规则为所述源分流用户面网元或所述目标分流用户面网元检测数据包对应的规则、所述第四数据包转发规则为所述源分流用户面网元或所述目标分流用户面网元转发数据包对应的规则。
  7. 根据权利要求5或6所述的方法，其特征在于，
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包检测规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到，所述第三数据包转发规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包转发规则中添加所述目标接入网设备的隧道端点标识和所述目标接入网设备的网际协议地址得到；
    若所述用户面网元为所述源分流用户面网元，所述第三数据包检测规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包检测规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到，所述第三数据包转发规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包转发规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到。
  8. 一种指示信息的传输方法，其特征在于，所述方法应用于会话管理网元，所述方法包括：
    从中间会话管理网元接收第一指示信息，所述第一指示信息用于指示所述中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元；
    根据所述第一指示信息向所述中间会话管理网元发送第二指示信息，所述第二指示信息用于指示所述目标用户面网元缓存上行数据包；
    向所述中间会话管理网元发送第四指示信息，所述第四指示信息用于指示所述目标用户面网元转发所述上行数据包，所述第四指示信息为所述会话管理网元获知目标应用网元已完成切换后发送的指示信息。
  9. 根据权利要求8所述的方法，其特征在于，所述方法还包括：
    向所述中间会话管理网元发送第二数据包检测规则、第二数据包转发规则和第六指示信息；所述第六指示信息用于指示以下一项或多项：所述第二数据包检测规则为所述源分流用户面网元或所述目标分流用户面网元检测数据包对应的规则、所述第二数据包转发规则为所述源分流用户面网元或所述目标分流用户面网元转发数据包对应的规则。
  10. 一种指示信息的传输方法，其特征在于，所述方法应用于用户面网元，所述方法包括：
    从中间会话管理网元接收第三指示信息，所述第三指示信息用于指示所述用户面网元缓存上行数据包；
    从所述中间会话管理网元接收第五指示信息，所述第五指示信息用于指示所述用户面网元转发所述上行数据包。
  11. 根据权利要求10所述的方法，其特征在于，所述方法还包括：
    从所述中间会话管理网元接收第一数据包转发控制协议请求消息，所述第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第一数据包检测规则为所述源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，所述第一数据包转发规则为所述源分流用户面网元向所述源用户面网元转发来自所述目标分流用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第一数据包检测规则为所述目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，所述第一数据包转发规则为所述目标分流用户面网元向所述源分流用户面网元转发来自所述目标接入网设备的数据包对应的规则。
  12. 根据权利要求10或11所述的方法，其特征在于，
    若所述用户面网元为所述目标分流用户面网元，所述第一数据包检测规则为所述中间会话管理网元根据第六指示信息在第二数据包检测规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到，所述第一数据包转发规则为所述中间会话管理网元根据所述第六指示信息在第二数据包转发规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到；
    若所述用户面网元为所述源分流用户面网元，所述第一数据包检测规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包检测规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到，所述第一数据包转发规则为所述中间会话管理网元根据所述第六指示信息在所述第二数据包转发规则中添加所述源用户面网元的隧道端点标识和所述源用户面网元的网际协议地址得到；
    其中，所述第六指示信息用于指示以下一项或多项：所述第二数据包检测规则为所述源分流用户面网元或所述目标分流用户面网元检测数据包对应的规则、所述第二数据包转发规则为所述源分流用户面网元或所述目标分流用户面网元转发数据包对应的规则。
  13. 一种消息传输方法，其特征在于，所述方法应用于用户面网元，所述方法包括：
    从中间会话管理网元接收第三数据包转发控制协议请求消息，所述第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第三数据包检测规则为所述源分流用户面网元检测来自远端用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流 用户面网元向所述目标分流用户面网元转发来自所述远端用户面网元的数据包对应的规则；或，所述第三数据包检测规则为所述源分流用户面网元检测来自源用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述源用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述目标分流用户面网元检测来自所述源分流用户面网元的数据包对应的规则，所述第三数据包转发规则为所述目标分流用户面网元向目标接入网设备转发来自所述源分流用户面网元的数据包对应的规则。
  14. 根据权利要求13所述的方法，其特征在于，
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述中间会话管理网元根据第七指示信息在第四数据包检测规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到，所述第三数据包转发规则为所述中间会话管理网元根据所述第七指示信息在第四数据包转发规则中添加所述目标接入网设备的隧道端点标识和所述目标接入网设备的网际协议地址得到；
    若所述用户面网元为所述源分流用户面网元，所述第三数据包检测规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包检测规则中添加所述源分流用户面网元的隧道端点标识和所述源分流用户面网元的网际协议地址得到，所述第三数据包转发规则为所述中间会话管理网元根据所述第七指示信息在所述第四数据包转发规则中添加所述目标分流用户面网元的隧道端点标识和所述目标分流用户面网元的网际协议地址得到；
    其中，所述第七指示信息用于指示以下一项或多项：所述第四数据包检测规则为所述源分流用户面网元或所述目标分流用户面网元检测数据包对应的规则、所述第四数据包转发规则为所述源分流用户面网元或所述目标分流用户面网元转发数据包对应的规则。
  15. 一种指示信息的传输方法，其特征在于，所述方法包括：
    中间会话管理网元向所述会话管理网元发送第一指示信息，所述第一指示信息用于指示所述中间会话管理网元已经插入目标分流用户面网元和所述目标用户面网元，以及已经删除源分流用户面网元和源用户面网元；
    所述会话管理网元根据所述第一指示信息向所述中间会话管理网元发送第二指示信息，所述第二指示信息用于指示所述目标用户面网元缓存上行数据包；
    所述目标用户面网元从所述中间会话管理网元接收第三指示信息，所述第三指示信息为所述中间会话管理网元根据所述第二指示信息发送，所述第三指示信息用于指示所述目标用户面网元缓存上行数据包；
    所述会话管理网元向所述中间会话管理网元发送第四指示信息，所述第四指示信息用于指示所述目标用户面网元转发所述上行数据包，所述第四指示信息为所述会话管理网元获知目标应用网元已完成切换后发送的指示信息；
    所述中间会话管理网元根据所述第四指示信息，向所述目标用户面网元发送第五指示信息，所述第五指示信息用于指示所述目标用户面网元转发所述上行数据包。
  16. 一种消息传输方法，其特征在于，所述方法包括：
    所述中间会话管理网元向所述用户面网元发送第三数据包转发控制协议请求消息，所述第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第三数据包检测规则为所述源分流用户面网元检测来自远端用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述远端用户面网元的数据包对应的规则；或，所述第三数据包检测规则为所述源分流用户面网元检测来自源用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述源用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述目标分流用户面网元检测来自所述源分流用户面网元的数据包对应的规则，所述第三数据包转发规则为所述目标分流用户面网元向目标接入网设备转发来自所述源分流用户面网元的数据包对应的规则。
  17. 一种中间会话管理网元，其特征在于，所述中间会话管理网元包括收发模块，所述收发模块，用于：
    向会话管理网元发送第一指示信息，所述第一指示信息用于指示所述中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元；
    从会话管理网元接收第二指示信息，所述第二指示信息用于指示所述目标用户面网元缓存上行数据包；
    根据所述第二指示信息，向所述目标用户面网元发送第三指示信息，所述第三指示信息用于指示所述目标用户面网元缓存上行数据包；
    从所述会话管理网元接收第四指示信息，所述第四指示信息用于指示所述目标用户面网元转发所述上行数据包；
    根据所述第四指示信息，向所述目标用户面网元发送第五指示信息，所述第五指示信息用于指示所述目标用户面网元转发所述上行数据包。
  18. 一种中间会话管理网元，其特征在于，所述中间会话管理网元包括收发模块，所述收发模块，用于向用户面网元发送第三数据包转发控制协议请求消息，所述第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第三数据包检测规则为所述源分流用户面网元检测来自远端用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述远端用户面网元的数据包对应的规则；或，所述第三数据包检测规则为所述源分流用户面网元检测来自源用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述源用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述目标分流用户面网元检测来自所述源分流用户面网元的数据包对应的规则，所述第三数据包转发规则为所述目标分流用户面网元向目标接入网设备转发来自所述源分流用户面网元的数据包对应的规则。
  19. 一种会话管理网元，其特征在于，所述会话管理网元包括收发模块，
    所述收发模块，用于从中间会话管理网元接收第一指示信息，所述第一指示信息用于指 示所述中间会话管理网元已经插入目标分流用户面网元和目标用户面网元，以及已经删除源分流用户面网元和源用户面网元；
    根据所述第一指示信息向所述中间会话管理网元发送第二指示信息，所述第二指示信息用于指示所述目标用户面网元缓存上行数据包；
    向所述中间会话管理网元发送第四指示信息，所述第四指示信息用于指示所述目标用户面网元转发所述上行数据包，所述第四指示信息为所述会话管理网元获知目标应用网元已完成切换后发送的指示信息。
  20. 一种用户面网元，其特征在于，所述用户面网元包括收发模块，
    所述收发模块，用于从所述中间会话管理网元接收第一数据包转发控制协议请求消息，所述第一数据包转发控制协议请求消息中包括第一数据包检测规则和第一数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第一数据包检测规则为所述源分流用户面网元检测来自目标分流用户面网元的数据包对应的规则，所述第一数据包转发规则为所述源分流用户面网元向所述源用户面网元转发来自所述目标分流用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第一数据包检测规则为所述目标分流用户面网元检测来自目标接入网设备的数据包对应的规则，所述第一数据包转发规则为所述目标分流用户面网元向所述源分流用户面网元转发来自所述目标接入网设备的数据包对应的规则。
  21. 一种用户面网元，其特征在于，所述用户面网元包括收发模块，
    所述收发模块，用于从中间会话管理网元接收第三数据包转发控制协议请求消息，所述第三数据包转发控制协议请求消息包括第三数据包检测规则和第三数据包转发规则；
    若所述用户面网元为源分流用户面网元，所述第三数据包检测规则为所述源分流用户面网元检测来自远端用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述远端用户面网元的数据包对应的规则；或，所述第三数据包检测规则为所述源分流用户面网元检测来自源用户面网元的数据包对应的规则，所述第三数据包转发规则为所述源分流用户面网元向所述目标分流用户面网元转发来自所述源用户面网元的数据包对应的规则；
    若所述用户面网元为所述目标分流用户面网元，所述第三数据包检测规则为所述目标分流用户面网元检测来自所述源分流用户面网元的数据包对应的规则，所述第三数据包转发规则为所述目标分流用户面网元向目标接入网设备转发来自所述源分流用户面网元的数据包对应的规则。
  22. 一种通信装置，其特征在于，包括处理器，处理器调用存储器中存储的计算机程序实现如权利要求1-14任意一项的方法。
  23. 一种计算机可读存储介质，其特征在于，计算机可读存储介质中存储有计算机程序，当计算机程序被运行时，实现如权利要求1-14任意一项的方法。
  24. 一种芯片，其特征在于，所述芯片包括至少一个处理器和接口，所述处理器用于读取并执行存储器中存储的指令，当所述指令被运行时，使得所述芯片执行如权利要求1-14任一 项所述的方法。
  25. 一种包含指令的计算机程序产品，当其在计算机上执行时，使得权利要求1-14任一项所述的方法被执行。
  26. 一种通信系统，其特征在于，所述通信系统包括中间会话管理网元、会话管理网元和用户面网元，所述中间会话管理网元用于执行权利要求1-4中任一项所述的方法，所述会话管理网元用于执行权利要求8-9中任一项所述的方法，所述用户面网元用于执行权利要求10-12中任一项所述的方法。
  27. 一种通信系统，其特征在于，所述通信系统包括中间会话管理网元和用户面网元，所述中间会话管理网元用于执行权利要求5-7中任一项所述的方法，所述用户面网元用于执行权利要求13-14中任一项所述的方法。
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WO2019174440A1 (zh) * 2018-03-14 2019-09-19 华为技术有限公司 切换用户面网元的方法、装置和系统
WO2019192417A1 (zh) * 2018-04-03 2019-10-10 华为技术有限公司 指示业务分流的方法和装置
WO2020253551A1 (zh) * 2019-06-17 2020-12-24 华为技术有限公司 通信方法和通信装置

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WO2019174440A1 (zh) * 2018-03-14 2019-09-19 华为技术有限公司 切换用户面网元的方法、装置和系统
WO2019192417A1 (zh) * 2018-04-03 2019-10-10 华为技术有限公司 指示业务分流的方法和装置
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