CN112584328A

CN112584328A - Multicast communication method and device

Info

Publication number: CN112584328A
Application number: CN201910944825.1A
Authority: CN
Inventors: 朱强华; 吴问付
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-09-30
Filing date: 2019-09-30
Publication date: 2021-03-30
Anticipated expiration: 2039-09-30
Also published as: CN112584328B

Abstract

The embodiment of the application provides a multicast communication method which is applied to a 5G LAN communication scene. Wherein, the method can comprise the following steps: in the process of establishing a PDU session of UE, an SMF network element sets routing rule information according to an acquired multicast ACL of the UE, wherein the routing rule information comprises a first type routing rule and a second type routing rule, and the routing rule included in the second type routing rule is set to be in a deactivation state; sending the routing rule information to a UPF network element; and when the UPF network element receives a first IGMP message which is from the UE and used for requesting to join the first multicast group and determines that the first multicast group is a multicast group which the UE allows to join, setting the state of a routing rule corresponding to the first multicast group in the second type of routing rules as an activated state so that the UPF network element can realize the forwarding control of the multicast message. And activating the corresponding routing rule under the condition of activation, thereby efficiently and flexibly realizing the forwarding control of the multicast message.

Description

Multicast communication method and device

Technical Field

The embodiment of the present application relates to the field of communications technologies, and in particular, to a multicast communication method and apparatus.

Background

Accompany withDevelopment of the telecommunication technology, fifth generation (5)^thGeneration, 5G) mobile communication systems have been developed. The 5G system is composed of a terminal device, AN Access Network (AN), a core network (core), and a Data Network (DN). The terminal device, the access network and the core network are main components constituting a 5G system, and logically, they may be divided into two parts, namely a user plane and a control plane, where the control plane is responsible for management of the mobile network and the user plane is responsible for transmission of service data.

The 5G system may provide a 5G Local Area Network (LAN) service capable of providing two or more terminal devices in a group of terminal devices with Internet Protocol (IP) type communication or non-IP type (e.g., ethernet type) private communication. The 5G LAN service can be applied to the fields of home communication, enterprise office, factory manufacturing, Internet of vehicles, power grid transformation and the like. A 5G LAN may include a plurality of LAN members, which may be terminal devices. A 5G LAN may be referred to as a 5G LAN group. A certain terminal device in a 5G LAN group joins the 5G LAN group due to traffic demand or proprietary attributes, and the terminal device and other terminal devices in the 5G LAN group can communicate using the 5G LAN service. One terminal device may join one or more 5G LAN groups. If two terminal devices belong to different 5G LAN groups, the two terminal devices cannot communicate with each other through private communication.

The 5G LAN service can support three communication modes of unicast communication, multicast communication and broadcast communication. Currently, a user plane message forwarding mode is provided for unicast and broadcast communication, and a 5G core network can forward a unicast message and a broadcast message according to the message forwarding mode. However, for multicast communication, how to implement forwarding control of multicast packets by a 5G core network is a technical problem to be solved urgently.

Disclosure of Invention

The embodiment of the application provides a multicast communication method and a device thereof, which can efficiently and flexibly realize the forwarding control of multicast messages.

A first aspect of an embodiment of the present application provides a multicast communication method, including:

receiving routing rule information from a session management network element in the process of establishing a Protocol Data Unit (PDU) session of a terminal device; the routing rule information corresponds to multicast access control information of the terminal device, the multicast access control information includes indication information whether the terminal device allows to join one or more multicast groups, and the routing rule information includes a first type routing rule and a second type routing rule; the first type of routing rules comprise routing rules for processing Internet Group Management Protocol (IGMP) messages, the second type of routing rules comprise routing rules corresponding to multicast addresses of multicast groups allowed to be added by the terminal equipment, and the state of the routing rules included in the second type of routing rules is a deactivation state;

receiving a first IGMP message from the terminal equipment, wherein the first IGMP message is used for requesting to join a first multicast group;

and when the first multicast group is any one multicast group which is allowed to be added by the terminal equipment in one or more multicast groups, setting the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state.

The method provided in the first aspect may be performed by a user plane network element, or may be performed by a component (e.g., a processor, a chip, or a system of chips) of the user plane network element. In a multicast communication scenario, when receiving a first IGMP message from a terminal device requesting to join a first multicast group, a user plane network element judges whether the terminal device is allowed to join the first multicast group according to a first type of routing rule sent by a session management network element, and sets a routing rule corresponding to a multicast address of the first multicast group to an active state if the terminal device is allowed to join the first multicast group, so that the user plane network element can match the routing rule in the active state with the multicast message when receiving the multicast message, thereby improving matching efficiency, and further the user plane network element can efficiently and flexibly implement forwarding control of the multicast message.

The multicast access control information may be a multicast Access Control List (ACL), where the multicast ACL includes indication information of whether the terminal device is allowed to join one or more multicast groups, so that the session management network element sets routing rule information according to the multicast ACL.

In a possible implementation manner, the determining, by the user plane network element, that the first multicast group is a multicast group that the terminal device is allowed to join in the one or more multicast groups according to the first type of routing rule may specifically include: the user plane network element matches the first IGMP packet with the first class of routing rules, and further determines a first Packet Detection Rule (PDR) matching the first IGMP packet and a Forwarding Action Rule (FAR) associated with the first PDR from the first class of routing rules, where the FAR associated with the first PDR indicates that the terminal device is allowed to join the first multicast group. Therefore, the user plane network element can determine that the first multicast group is a multicast group which the terminal device is allowed to join according to the FAR associated with the first PDR.

And the FAR associated with the first PDR is also used for instructing the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to be an activated state.

When the FAR associated with the first PDR indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to the active state, the FAR associated with the first PDR specifically indicates that the FAR is a first value through the value of the specified field in the FAR associated with the first PDR.

In a possible implementation manner, after the user plane network element sets the routing rule corresponding to the multicast address of the first multicast group to the activated state, if a second IGMP packet for requesting to exit the first multicast group is received from the terminal device, it is determined that the terminal device exits the first multicast group according to the first class of routing rules, and the routing rule corresponding to the multicast address of the first multicast group in the second class of routing rules is set to the deactivated state.

Specifically, the user plane network element matches the second IGMP packet with the first type of routing rule, and further determines a second PDR matching the second IGMP packet and an FAR associated with the second PDR from the first type of routing rule, where the FAR associated with the second PDR indicates that the terminal device exits the first multicast group. Therefore, the user plane network element can determine that the terminal equipment exits the first multicast group according to the FAR associated with the second PDR.

And the FAR associated with the second PDR is also used for indicating the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to be a deactivation state.

When the FAR associated with the second PDR indicates that the terminal device exits the first multicast group and indicates that the user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to the deactivated state, the FAR may specifically indicate that the FAR associated with the second PDR takes the value of the specified field as the second value.

In a possible implementation manner, the user plane network element determines, according to the first class routing rule, that the terminal device is not allowed to join the second multicast group, when receiving a third IGMP packet from the terminal device, where the third IGMP packet is used to request to join the second multicast group.

Specifically, the user plane network element matches the third IGMP packet with the first type of routing rule, and further determines, from the first type of routing rule, a third PDR matching the third IGMP packet and a FAR associated with the third PDR, where the FAR associated with the third PDR indicates that the terminal device is not allowed to join the second multicast group. And the user plane network element can determine that the terminal equipment is not allowed to join the second multicast group according to the FAR associated with the third PDR.

When the FAR associated with the third PDR indicates that the terminal device is not allowed to join the second multicast group, the FAR may specifically indicate that the FAR is a third value through a value of a specified field in the FAR associated with the third PDR.

In the above three manners, the designated field in the FAR may be an "action" field, and a value of the designated field may be a first value, a second value, or a third value, which is used to instruct the user plane network element to perform different actions.

In a possible implementation manner, after the user plane network element sets the routing rule corresponding to the multicast address of the first multicast group to the active state, if the multicast packet is received, the user plane network element skips the routing rule in the deactivated state in the process of searching the routing rule matched with the multicast packet in the second type of routing rule, and directly matches the routing rule in the active state with the multicast packet, so that the matching efficiency can be improved.

In a possible implementation manner, the routing rule in the second type of routing rule includes state indication information, where the state indication information is used to indicate that the state of the corresponding routing rule in the second type of routing rule is a deactivated state or an activated state. Thus, when the user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group as the activated state, the state indication information in the routing rule corresponding to the multicast address of the first multicast group can be set as the activated state; when the state of the routing rule corresponding to the multicast address of the first multicast group is set to the deactivated state, the state indication information in the routing rule corresponding to the multicast address of the first multicast group may be set to the deactivated state. The activation state or the deactivation state is indicated through the state indication information, and the display indication mode is adopted.

In a possible implementation, the routing rule information further includes a bitmap associated with the second type of routing rule, for example, any one of the second type of routing rule includes the bitmap. The bitmap includes N bits, where N is a natural number, and any bit in the bitmap has a mapping relationship with a multicast address of a multicast group that the terminal device allows to join, for example, a first bit corresponds to a multicast address of multicast group 1, and a second bit corresponds to a multicast address of multicast group 2.

The value of any bit in the bitmap can be set to be a first preset value or a second preset value; the first preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state.

The user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state, specifically: and determining a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule according to the mapping relation, and setting a value of the bit corresponding to the multicast address of the first multicast group as a second preset value.

The user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as a deactivation state, specifically: and determining a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule according to the mapping relation, and setting a value of the bit corresponding to the multicast address of the first multicast group as a first preset value.

The way of indicating the activation state or the deactivation state by the bitmap is a privacy indication way.

In a possible implementation manner, the user plane network element receives the mapping relationship from the session management network element, or the user plane network element is preconfigured with the mapping relationship, so that the user plane network element determines, according to the mapping relationship, a multicast address corresponding to each bit in the bitmap or a bit corresponding to each multicast address, and determines, according to a value of the bit, whether a routing rule corresponding to the multicast address of the corresponding multicast group is in an activated state or a deactivated state.

In a possible implementation manner, for the activated state or the deactivated state, the mode of indicating through the bitmap is performed, and when receiving the multicast packet, the user plane network element skips over a bit in the bitmap, which is a first preset value, determines a multicast address corresponding to a bit in the bitmap, which is a second preset value, according to the mapping relationship, and matches a routing rule corresponding to the multicast address corresponding to the bit in the second preset value with the multicast packet, so that matching efficiency can be improved.

In a possible implementation manner, for a manner that the activation state or the deactivation state is indicated by a bitmap, when receiving a multicast packet, a user plane network element determines a multicast address corresponding to a bit in the bitmap according to a mapping relationship, skips a routing rule corresponding to the multicast address corresponding to a first preset value, and matches the routing rule corresponding to the multicast address corresponding to a second preset value with the multicast packet, thereby improving matching efficiency.

Wherein, the first preset value may be "0", and the second preset value may be "1".

In a possible implementation manner, the routing rule information further includes an Active Member List (AML) associated with the second type of routing rule, for example, the second type of routing rule includes an active member list. The AML is empty or includes one or more multicast addresses, which are multicast addresses of multicast groups that the end devices are allowed to join. The AML is null, which indicates that the states of all routing rules included in the second type of routing rules are the deactivation states; when AML includes multicast address X, it shows that the state of the route rule corresponding to multicast address X is active state.

In the process of establishing the PDU session, the user plane network element receives an AML null, which may indicate that the routing rule corresponding to the multicast address of any multicast group that the terminal device allows to join is in a deactivated state.

The user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state, specifically: the multicast address of the first multicast group is added to the active member list. The AML includes the multicast address of the first multicast group, and may indicate that the state of the routing rule corresponding to the multicast address of the first multicast group is an active state.

Then, when the user plane network element receives a second IGMP packet from the terminal device, where the second IGMP packet is used to request to exit the first multicast group, the user plane network element sets a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to a deactivated state, which specifically includes: the multicast address of the first multicast group is deleted from the active member list. After the deletion, the activation member list does not include the multicast address of the first multicast group, and may indicate that the state of the routing rule corresponding to the multicast address of the first multicast group is a deactivated state.

And under the condition that the user plane network element receives the multicast message, in the process of searching the routing rule matched with the multicast message in the second type of routing rule, the multicast message is matched with the multicast address included in the activated member list, and then the routing rule matched with the multicast message is determined, so that the matching efficiency is improved.

The way of indicating the activation state or the deactivation state by the activation member list is a privacy indication way.

In the three indication modes of indicating through the status indication information, indicating through the bitmap, and indicating through the active member list, one indication mode may be adopted, or two or three may be combined, for example, indicating through the status indication information and indicating through the active member list may be combined, then the user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an active state, specifically: and the user plane network element sets the state indication information in the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state, and adds the multicast address of the first multicast group into the activated member list.

In a possible implementation manner, the routing rule information may be carried in an N4 session message at a user level, that is, in an N4 session message corresponding to a PDU session of the terminal device, so that the PDU session-associated user plane network element may receive the routing rule information; or may be carried in a group-level N4 session message, that is, in a group-level N4 session message corresponding to the 5G LAN group to which the terminal device belongs, so that the user plane network element serving the 5G LAN group may receive the routing rule information.

A second aspect of the embodiments of the present application provides a multicast communication method, including:

in the process of establishing a PDU session of a terminal device, acquiring multicast access control information of the terminal device, wherein the multicast access control information comprises indication information of whether the terminal device allows to join one or more multicast groups;

setting routing rule information according to the multicast access control information, wherein the routing rule information comprises a first type of routing rule and a second type of routing rule; the first type of routing rule is a routing rule for processing an IGMP message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which is allowed to be added by terminal equipment, and the state of the routing rule in the second type of routing rule is a deactivation state;

and sending the routing rule information to the user plane network element.

The method provided in the second aspect may be performed by a session management network element, or may be performed by a component (e.g., a processor, a chip, or a system-on-chip) of the session management network element. In a multicast communication scene, in the process of establishing a PDU session of a terminal device, routing rule information is set according to the acquired multicast access control information of the terminal device and is sent to a user plane network element, so that the user plane network element can efficiently and flexibly realize forwarding control of multicast messages according to the routing rule information.

The multicast access control information may be a multicast ACL, where the multicast ACL includes indication information of whether the terminal device is allowed to join one or more multicast groups, and thus the session management network element may set the first-type routing rule and the second-type routing rule according to the indication information.

In a possible implementation manner, in the process of establishing the PDU session, the session management network element sets the state of the routing rule included in the second type of routing rule as a deactivated state by default, so that the user plane network element sets the routing rule corresponding to the multicast address of the corresponding multicast group as an activated state under the condition that the user plane network element needs to be activated.

In a possible implementation manner, the setting, by the session management network element, the first type of routing rule according to the multicast access control information includes: aiming at a first IGMP message used for requesting to join a first multicast group by the terminal equipment, setting a first PDR matched with the first IGMP message and a FAR associated with the first PDR, wherein the FAR associated with the first PDR indicates that the terminal equipment is allowed to join the first multicast group and indicates a user plane network element to set the state of a routing rule corresponding to a multicast address of the first multicast group in a second type of routing rule to be an activated state; wherein, the first multicast group is a multicast group which is allowed to join by the terminal device in one or more multicast groups. Therefore, when the user plane network element receives the first IGMP message and the first IGMP message matches the first PDR, the terminal device is determined to be allowed to join the first multicast group according to the FAR associated with the first PDR and the state of the routing rule corresponding to the multicast address of the first multicast group is set to be an activated state.

In a possible implementation manner, the setting, by the session management network element, the first type of routing rule according to the multicast access control information includes: setting a second PDR matched with the second IGMP message and a FAR associated with the second PDR for a second IGMP message used for requesting to quit the first multicast group by the terminal equipment, wherein the FAR associated with the second PDR indicates that the terminal equipment quits the first multicast group and indicates a user plane network element to set the state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as a deactivation state; wherein, the first multicast group is a multicast group which is allowed to join by the terminal device in one or more multicast groups. Therefore, when the user plane network element receives the second IGMP message and the second IGMP message matches the second PDR, the terminal device is determined to exit the first multicast group according to the FAR associated with the second PDR and the state of the routing rule corresponding to the multicast address of the first multicast group is set to be a deactivation state.

In a possible implementation manner, the setting, by the session management network element, the first type of routing rule according to the multicast access control information includes: setting a third PDR matched with the third IGMP message and a FAR associated with the third PDR aiming at a third IGMP message used for requesting to join the second multicast group by the terminal equipment, wherein the FAR associated with the third PDR indicates that the terminal equipment is not allowed to join the second multicast group; wherein the second multicast group is a multicast group that the terminal device is not allowed to join in one or more multicast groups. Therefore, when the user plane network element receives the third IGMP packet and the third IGMP packet matches the third PDR, it is determined that the terminal device is not allowed to join the second multicast group according to the FAR associated with the third PDR.

In the above manner, the specified field in the FAR may be an "action" field, and a value of the specified field may be a first value, a second value, or a third value, which is used to instruct the user plane network element to perform different actions.

In a possible implementation manner, the routing rule in the second type of routing rule includes state indication information, where the state indication information is used to indicate that the state of the corresponding routing rule of the second type of routing rule is an activated state or a deactivated state.

In a possible implementation, the routing rule information further includes a bitmap associated with the second type of routing rule, for example, any one of the routing rules in the second type of routing rule includes a bitmap. The bitmap comprises N bits, wherein N is a natural number; any bit in the bitmap has a mapping relation with the multicast address of the multicast group which the terminal device allows to join. Setting the value of any bit in the bitmap as a first preset value or a second preset value; the first preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state.

The session management network element sets a second type of routing rule according to the multicast access control information, and the method comprises the following steps: setting the value of a bit corresponding to the multicast address of the multicast group allowed to be added by the terminal equipment in the bitmap as a first preset value according to the multicast access control information; and/or setting the value of the bit corresponding to the multicast address of the multicast group which is not allowed to be added by the terminal equipment in the bitmap as a second preset value.

In a possible implementation manner, the session management network element sends a mapping relationship to the user plane network element, so that the user plane network element determines, according to the mapping relationship, a multicast address corresponding to each bit in the bitmap or a bit corresponding to each multicast address, and determines, according to a value of the bit, whether a routing rule corresponding to the multicast address of the corresponding multicast group is in an activated state or a deactivated state.

In one possible implementation, the routing rule information further includes an active member list associated with the second type of routing rule, for example, the second type of routing rule includes an active member list. The session management network element sets a second type of routing rule according to the multicast access control information, and the method comprises the following steps: the activation member list is set to be null, that is, the activation member list does not include any multicast address, and may indicate that the routing rule corresponding to the multicast address of any multicast group that the terminal device allows to join is in a deactivated state.

In one possible implementation, the session management network element receives an N4 report from the user plane network element, the N4 report being used to instruct the terminal device to join or leave the first multicast group; updating a routing rule corresponding to the multicast address of the first multicast group in the N4 session at the group level corresponding to the 5G LAN group of the user plane network element and/or other user plane network elements according to the report of N4; and sending the routing rule corresponding to the multicast address of the first multicast group in the updated group-level N4 session to the user plane network element and/or other user plane network elements, so that the user plane network element serving the 5G LAN group can acquire the routing rule corresponding to the multicast address of the first multicast group in the updated group-level N4 session, and further control the forwarding of the multicast message.

A third aspect of the embodiments of the present application provides a communication apparatus for implementing the above various methods. The communication device may be the user plane network element in the first aspect, or a device including the user plane network element; alternatively, the communication device may be the session management network element in the second aspect, or a device including the session management network element. The communication device comprises corresponding modules, units or means (means) for implementing the above method, and the modules, units or means can be implemented by hardware, software or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

A fourth aspect of the embodiments of the present application provides a communication apparatus, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the communication device to perform the method of any of the above aspects. The communication device may be the user plane network element in the first aspect, or a device including the user plane network element; alternatively, the communication device may be the session management network element in the second aspect, or a device including the session management network element.

A fifth aspect of the embodiments of the present application provides a communication apparatus, including: a processor; the processor is configured to be coupled to the memory, and to execute the method according to any one of the above aspects after reading the instruction in the memory. The communication device may be the user plane network element in the first aspect, or a device including the user plane network element; alternatively, the communication device may be the session management network element in the second aspect, or a device including the session management network element.

A sixth aspect of embodiments of the present application provides a computer-readable storage medium having stored therein instructions, which, when executed on a computer, cause the computer to perform the method of any of the above aspects.

A seventh aspect of embodiments of the present application provides a computer program product comprising instructions that, when executed on a computer, enable the computer to perform the method of any of the above aspects.

An eighth aspect of the embodiments of the present application provides a communication device (for example, the communication device may be a chip or a chip system), which includes a processor, and is configured to implement the functions recited in any of the above aspects. In one possible design, the communication device further includes a memory for storing necessary program instructions and data. When the communication device is a chip system, the communication device may be constituted by a chip, or may include a chip and other discrete devices.

The technical effects brought by any design manner of the third aspect to the eighth aspect may be referred to the technical effects brought by the first aspect or the second aspect, and are not described herein again.

A ninth aspect of the present embodiment provides a multicast communication system, including a session management network element and a user plane network element;

a session management network element, configured to acquire multicast access control information of a terminal device during a PDU session establishment procedure of the terminal device, where the multicast access control information includes indication information of whether the terminal device allows to join one or more multicast groups; setting routing rule information according to the multicast access control information; the routing rule information comprises a first type of routing rule and a second type of routing rule; the first type of routing rule comprises a routing rule for processing an IGMP message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which is allowed to be added by terminal equipment, and the state of the routing rule in the second type of routing rule is a deactivation state; sending routing rule information to a user plane network element;

the user plane network element is used for receiving the routing rule information; receiving a first IGMP message from the terminal equipment, wherein the first IGMP message is used for requesting to join a first multicast group; and when the first multicast group is any one multicast group which is allowed to be added by the terminal equipment in one or more multicast groups, setting the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state.

In a possible implementation manner, the session management network element is specifically configured to set a second type routing rule and a first type routing rule according to the multicast access control information, and set a state of a routing rule included in the second type routing rule to a deactivated state.

In a possible implementation manner, the session management network element is specifically configured to set, for the first IGMP packet, a first PDR matched with the first IGMP packet and an FAR associated with the first PDR; setting the value of a specified field in the FAR associated with the first PDR as a first value; the first value indicates that the terminal equipment is allowed to join the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state;

the user plane network element is specifically configured to match the first IGMP packet with the first class routing rule; acquiring FAR associated with the first PDR under the condition that the first PDR is matched; and the value of the specified field in the FAR associated with the first PDR is a first value, the terminal equipment is determined to be allowed to join the first multicast group, and the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to be an activated state.

In a possible implementation manner, the session management network element is specifically configured to set, for a second IGMP packet used by the terminal device to request to exit the first multicast group, a second PDR matched with the second IGMP packet and a FAR associated with the second PDR; setting the value of a designated field in the FAR associated with the second PDR as a second value; the second value indicates the terminal equipment to exit the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as a deactivation state;

the user plane network element is also used for receiving a second IGMP message and matching the second IGMP message with the first class routing rule; acquiring FAR associated with the second PDR under the condition of matching the second PDR; and the value of the specified field in the FAR associated with the second PDR is a second value, the terminal equipment is determined to exit the first multicast group, and the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to be a deactivation state.

In a possible implementation manner, the session management network element is specifically configured to set, for a third IGMP packet used by the terminal device to request to join the second multicast group, a third PDR matched with the third IGMP packet and a FAR associated with the third PDR; setting the value of a specified field in the FAR associated with the third PDR as a third value; the third value indicates that the terminal equipment is not allowed to join the second multicast group; the second multicast group is a multicast group which is not allowed to be added by the terminal equipment in one or more multicast groups;

the user plane network element is also used for receiving a third IGMP message and matching the third IGMP message with the first class routing rule; acquiring FAR associated with the third PDR under the condition of matching with the third PDR; and the value of the specified field in the FAR associated with the second PDR is a third value, and the terminal equipment is determined not to be allowed to join the second multicast group.

In a possible implementation manner, the user plane network element is further configured to receive a multicast packet; and in the process of searching the routing rule matched with the multicast message in the second type of routing rule, skipping the routing rule in the deactivated state, and matching the routing rule in the activated state with the multicast message.

In a possible implementation manner, the routing rule information further includes a bitmap associated with the second type of routing rule, the bitmap includes N bits, and N is a natural number; any bit in the bitmap has a mapping relation with the multicast address of the multicast group allowed to be added by the terminal equipment;

the value of any bit in the bitmap can be set to be a first preset value or a second preset value; the first preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state;

the session management network element is specifically configured to set, according to the multicast access control information, a value of a bit corresponding to a multicast address of a multicast group that the terminal device is allowed to join in the bitmap as a first preset value; and/or setting the value of a bit corresponding to the multicast address of the multicast group which is not allowed to be added by the terminal equipment in the bitmap as a second preset value;

the user plane network element is specifically configured to, when the first multicast group is any one multicast group that the terminal device is allowed to join in one or more multicast groups, determine, according to the mapping relationship, a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule, and set a value of the bit corresponding to the multicast address of the first multicast group to a second preset value.

And then, the user plane network element is configured to, when the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set as the deactivated state, specifically, determine, according to the mapping relationship, a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule, and set a value of the bit corresponding to the multicast address of the first multicast group to a first preset value.

In a possible implementation manner, the session management network element is further configured to send the mapping relationship to the user plane network element.

And the user plane network element is also used for receiving the multicast message, skipping the bit which is the first preset value in the bitmap, determining the multicast address corresponding to the bit which is the second preset value in the bitmap according to the mapping relation, and matching the routing rule corresponding to the multicast address corresponding to the bit which is the second preset value with the multicast message.

And the user plane network element is also used for receiving the multicast message, determining the multicast address corresponding to the bit in the bitmap according to the mapping relation, skipping the routing rule corresponding to the multicast address corresponding to the first preset value, and matching the routing rule corresponding to the multicast address corresponding to the second preset value with the multicast message.

In one possible implementation, the routing rule information further includes an active member list associated with the second type of routing rule;

when the session management network element is used for setting the second type routing rule, the session management network element is specifically used for setting the active member list to be null;

the user plane network element is configured to, when the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to the active state, specifically, add the multicast address of the first multicast group to the active member list.

And then, the user plane network element is configured to, when the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to be the deactivated state, specifically delete the multicast address of the first multicast group from the active member list.

In a possible implementation manner, the user plane network element is further configured to send an N4 report to the session management network element, where the N4 report is used to instruct the terminal device to join or leave the first multicast group; the terminal device belongs to the 5G LAN group;

and the session management network element is further used for updating the routing rule corresponding to the multicast address of the first multicast group in the N4 session at the group level corresponding to the 5G LAN group of the user plane network element and/or other user plane network elements according to the report of the N4.

For technical effects of the tenth aspect, reference may be made to technical effects brought by any possible implementation manner of the first aspect or the second aspect, which are not described herein again.

Drawings

FIG. 1 is a schematic diagram of a network architecture of a 5G system;

FIG. 2 is a schematic diagram of a user plane architecture for a 5G LAN service;

fig. 3 is a communication diagram of a multicast communication;

FIG. 4a is an exemplary diagram of a user-level N4 session;

FIG. 4b is an exemplary diagram of a group-level N4 session;

fig. 5 is a schematic flow chart of a user plane forwarding packet;

FIG. 6 is a diagram illustrating a network architecture to which embodiments of the present application are applied;

fig. 7 is a flowchart illustrating a multicast communication method according to an embodiment of the present application;

fig. 8 is a schematic flowchart of a process of acquiring multicast control information according to an embodiment of the present application;

fig. 9a is a diagram of an example of multicast communication provided by an embodiment of the present application;

fig. 9b is a diagram of another example of multicast communication according to an embodiment of the present application;

fig. 9c is a diagram of another example of multicast communication provided in the embodiment of the present application;

fig. 10 is a flowchart illustrating another multicast communication method according to an embodiment of the present application;

fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of another communication device according to an embodiment of the present application.

Detailed Description

In order to better understand the technical solutions provided by the embodiments of the present application, first, the technologies or names related to the embodiments of the present application are introduced.

1. 5G system and 5G LAN

(1) The 5G system is composed of an access network, a core network and a data network. Optionally, the 5G system may further include a terminal device. Fig. 1 is a schematic diagram of a network architecture of a 5G system.

The terminal equipment has a wireless transceiving function, can be deployed on land and comprises an indoor or outdoor, handheld, wearable or vehicle-mounted terminal; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal device may be a mobile phone (mobile phone), a tablet computer (Pad), a computer with wireless transceiving function, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a vehicle-mounted terminal device, a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), a wearable terminal device, and so on. A terminal device may also sometimes be referred to as a terminal, User Equipment (UE), access terminal device, in-vehicle terminal, industrial control terminal, UE unit, UE station, mobile station, remote terminal device, mobile device, UE agent, or UE device, etc. The terminal equipment may also be fixed or mobile. Fig. 1 and terminal equipment in this embodiment are introduced by taking UE as an example.

The access network may be a Radio Access Network (RAN). The access network can provide a network access function for authorized users in a specific area, and can determine transmission tunnels with different qualities according to the level of the users, the service requirements and the like so as to transmit user data. The access network forwards control signals and user data between the UE and the core network. The access network may include an access network device (or referred to as an access device), and the access network device may be, for example, a base station in a Long Term Evolution (LTE) system or a base station in a New Radio (NR) system, a base station of a subsequent 3GPP evolution, an access node in a WiFi system, a wireless relay node, a wireless backhaul node, and the like. The base station may be: macro base stations, micro base stations, pico base stations, small stations, relay stations, or balloon stations, etc.

The core network is responsible for maintaining subscription data of the mobile network and providing functions of session management, mobility management, policy management, security authentication and the like for the UE. The core network may include the following network elements: a User Plane Function (UPF), an authentication service function (AUSF), a Session Management Function (SMF), a Network Slice Selection Function (NSSF), a network open function (NEF), a network function repository function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), and an Application Function (AF). The network elements except the UPF in the network elements belong to the core network control plane network element.

The UPF is used for executing user data packet forwarding according to the routing rule of the SMF, for example, sending uplink data to DN or other UPFs; and forwarding the downlink data to other UPFs or access networks. The interface between the UPFs is an N19 interface, and the interface between the UPFs and the DN is an N6 interface. AUSF for performing security authentication of the UE. And the AMF is mainly responsible for access management and mobility management of the UE. The SMF is mainly responsible for session management of the UE, allocates resources for the session of the UE and releases the resources. Where the resources may include quality of service (QoS) for the session, routing rules, session path, etc. NSSF, for selecting network slices for the UE. NEF for developing network functions to third parties. NRF, used to provide storage function and selection function of network function entity information for other network elements. UDM for storing user data such as subscription data, authentication/authorization data, etc. PCF, responsible for providing policy to AMF, SMF, such as QoS policy, slice selection policy, etc. The AF, which may be a third party device, may belong to an external data network or core network.

The data network is used for providing service for users, and may be a private network, such as a local area network; or an external network not controlled by the operator, such as the Internet (Internet); it may also be a proprietary network co-deployed by the operator, such as a network providing an IP Multimedia Subsystem (IMS).

(2) The 5G LAN service is capable of providing private communication of IP type or non-IP type for two or more terminal devices in a group of terminal devices. For example, devices in a factory may form a 5G LAN group, and devices in the 5G LAN group may send ethernet packets to each other; alternatively, office equipment (e.g., cell phones, computers, laptops, etc.) of employees in a department of an enterprise may form a 5G LAN group, send IP packets to each other, etc.

Please refer to fig. 2, which is a schematic diagram of a user plane architecture of the 5G LAN service. Wherein the terminal device establishes a session to a UPF network element providing a 5G LAN service, thereby accessing to the UPF network element providing the 5G LAN service. A UPF network element providing 5G LAN services may interwork with an existing Local Area Network (LAN) in the data network, e.g. communicate with a Personal Computer (PC) in the LAN, via an N6 interface; or, the UPF network element providing the 5G LAN service may also associate sessions of different terminal devices through an internal interface (internal interface) of the UPF network element or a connection between the UPF network elements, so as to implement private communication, which is not specifically limited in this embodiment of the present application.

The 5G LAN may also be described as a 5G Virtual Network (VN), a 5G LAN group (group), a 5G VN group, or a 5G LAN-type service (type service), and the name of the 5G LAN is not limited in the embodiment of the present application.

2. Unicast (unicast) communication, broadcast (broadcast) communication, and multicast (multicast or group) communication

(1) Unicast communication refers to a one-to-one communication method. For example, terminal a sends a message to terminal B.

(2) Broadcast communication refers to a one-to-many communication method, and one local area network (for example, 5G LAN) in a network corresponds to one broadcast domain. The terminal devices subscribed to the LAN may form a broadcast group (which may also be referred to as a LAN group). The terminal device subscribed to the LAN may be referred to as a member of the broadcast group, that is, the terminal device joins the broadcast group (may join one or more broadcast groups) during the subscription process.

Any terminal device in the broadcast group which has accessed the network can be used as a broadcast source to send a broadcast message; meanwhile, the broadcast message can be received as a broadcast member. For example, assume that the group members that have already accessed the network in the broadcast group include terminal device 1, terminal device 2, terminal device 3, terminal device 4, terminal device 5, and terminal device 6. Taking the terminal device 1 as a broadcast source as an example, that is, the broadcast packet sent by the terminal device 1 may be transmitted to the terminal device 2, the terminal device 3, the terminal device 4, the terminal device 5, and the terminal device 6 in the broadcast group, respectively.

(3) Multicast communication refers to a one-to-many communication mode, and one terminal device may send a message to a terminal device in a multicast group to which the terminal device belongs. At least one multicast source and a plurality of multicast members may form a multicast group (also referred to as a multicast group for short). Multicast communication may also be described as multicast communication or the like and, correspondingly, a multicast group may also be described as a multicast group or the like.

The multicast group address is used as a destination address, a source for sending messages is called a multicast source, and multicast users for receiving multicast data are called multicast members. I.e. the multicast is directional, the direction being from the multicast source to the multicast members. For example, the members in the 5GLAN group include terminal device 1, terminal device 2, terminal device 3, terminal device 4, terminal device 5, and terminal device 6. Taking the terminal device 1 as a multicast source, and the terminal device 3, the terminal device 5, and the terminal device 6 as multicast members to form a multicast group as an example, the corresponding communication schematic diagram can be shown in fig. 3, that is, the multicast message sent by the terminal device 1 can be respectively transmitted to the terminal device 3, the terminal device 5, and the terminal device 6 in the multicast group. In fig. 3, the end devices 2 and 4 are not multicast members of the multicast group, and therefore do not receive the multicast packet.

In this embodiment of the present application, a multicast source may be determined by an application layer of an Open System Interconnection (OSI) model, and if a certain terminal device needs to receive a multicast packet, it may send an IGMP join (join) packet to a network, and the network records that the terminal device joins a multicast group, and then forwards the multicast packet sent by the multicast source to the terminal device. Correspondingly, a certain terminal device may leave a certain multicast group by sending an IGMP leave (leave) message to the network, and the network records that the terminal device leaves the multicast group, and the multicast message sent by the multicast source is not forwarded to the terminal device.

The multicast address may be an IP version 4 (IPv 4) address or a multicast IP version 6(IP version 6, IPv6) address allocated by an Internet Assigned Number Authority (IANA), and the range of the multicast IPv4 address is 224.0.0.0-239.255.255.255; or, the multicast address may also be a multicast Media Access Control (MAC) address in which the last 48-bit of the 48-bit higher bits is constantly 1; alternatively, the multicast address may also be a reserved multicast address, such as the multicast MAC address with the previous 24 bits being 0x01005e or 224.0.0.1; alternatively, the multicast address may be another address, and specific reference may be made to the definition of the existing multicast address, which is not described herein again.

3. N4 Session

The N4 session in the embodiment of the present application includes a user-level N4 session and a group (group) -level N4 session. Wherein, in the 5G network, the N4 session can be created by the SMF network element on the UPF network element.

For example, the N4 session at the user level on the UPF network element may specifically be an N4 session corresponding to a Protocol Data Unit (PDU) session created on the UPF network element by the SMF network element when a terminal device establishes the PDU session. The functions of the UPF network element are that the UPF network element receives the message (such as multicast message) sent by the terminal equipment through the N4 session at the user level and the UPF network element sends the message (such as multicast message) to the terminal equipment through the N4 session at the user level.

As an example, the SMF network element may instruct the UPF network element to create an N4 session (i.e., a user-level N4 session) corresponding to the PDU session when the terminal device establishes the PDU session. Optionally, when the SMF network element receives the PDU session release request of the terminal device, the UPF network element is triggered to delete the N4 session corresponding to the PDU session. In other words, if a plurality of terminal devices are connected to the same UPF network element, the UPF network element needs to create an N4 session corresponding to the PDU session of each terminal device.

Illustratively, see FIG. 4a, which is an exemplary diagram of a user-level N4 session. In fig. 4a, terminal device 1 and terminal device 6 are connected to the UPF network element 1, then the SMF network element may instruct the UPF network element 1 to create an N4 session 1 corresponding to the PDU session of terminal device 1 when creating the PDU session of terminal device 1, and the SMF network element may instruct the UPF network element 1 to create an N4 session 6 corresponding to the PDU session of terminal device 6 when creating the PDU session of terminal device 6.

For convenience of description, in this embodiment of the present application, the N4 session corresponding to the PDU session of the terminal device 1 may be referred to as the N4 session of the terminal device 1, and the N4 session corresponding to the PDU session of the terminal device 6 may be referred to as the N4 session of the terminal device 6, and so on, which are described herein in a unified manner and will not be described again below.

Alternatively, to support communication between different UPF network elements in a 5G LAN service, as well as between a UPF network element and a DN, the SMF network element also needs to create a group-level N4 session for the corresponding 5G LAN group on each UPF network element providing the 5G LAN service.

As an example, the SMF network element may instruct the UPF network element to create a group-level N4 session corresponding to the 5G LAN group when creating the first PDU session anchored to the UPF network element of the 5G LAN group; and the SMF network element may instruct the UPF network element to delete the group-level N4 session corresponding to the 5G LAN group when releasing the last PDU session anchored to the UPF network element of the 5G LAN group. In this embodiment, a UPF network element may include one or more group-level N4 sessions, for example, if a UPF network element serves multiple 5G LAN groups, the UPF network element needs to create multiple group-level N4 sessions, and each group-level N4 session corresponds to a 5G LAN group. In this embodiment, for a 5G LAN group, a group-level N4 session corresponding to the 5G LAN group may be created for one or more UPF network elements serving the 5G LAN group, respectively.

Illustratively, see FIG. 4b, which is an exemplary diagram of a group-level N4 session. In fig. 4b, assuming that the SMF network element has instructed the UPF network element 1 to create an N4 session 1 corresponding to the PDU session of terminal device 1 when creating the PDU session of terminal device 1, the SMF network element may instruct the UPF network element 2 to create an N4 session 2 corresponding to the PDU session of terminal device 2 when creating the PDU session of terminal device 2. Furthermore, since the terminal device 1 within the 5G LAN group has access to the UPF network element 1, the SMF network element needs to instruct the UPF network element 2 to create a group-level N4 session 3 corresponding to the 5G LAN group; and the SMF network element instructs the UPF network element 1 to create a group-level N4 session 4 corresponding to the 5G LAN group. Alternatively, optionally, if the 5G LAN group needs to communicate with the DN, the SMF network element may also instruct the UPF network element 1 to create the N4 session 4 at the group level corresponding to the 5G LAN group, which is not specifically limited herein.

4. Multicast access control information and routing rule information

(1) In this embodiment of the present application, the multicast access control information may be a multicast Access Control List (ACL), where the multicast ACL includes indication information whether the terminal device is allowed to join one or more multicast groups, for example, see table 1 below.

TABLE 1

Serial number	Multicast address of multicast group	Whether or not to permit
			1	Multicast address 1	Is that
2	Multicast address 2	Whether or not
			…	…	…

It is assumed that table 1 is a multicast ACL corresponding to the terminal device 1, where a sequence number 1 indicates that the terminal device 1 is allowed to join a multicast group corresponding to the multicast address 1, and a sequence number 2 indicates that the terminal device 1 is not allowed to join a multicast group corresponding to the multicast address 2.

In a possible implementation manner, the multicast ACL includes only the multicast addresses of one or more multicast groups that the terminal device is allowed to join, optionally a multicast member list of the multicast group, and optionally a group identifier of the multicast group. In this way, the multicast ACL may be understood as a white list, i.e. a list of multicast groups that the terminal device is allowed to join. The white list in this manner can be seen, for example, in table 2 below.

TABLE 2

Serial number	Multicast address of multicast group
		1	Multicast address 1
2	Multicast address 2
		…	…

In this way, if the IGMP message sent by the terminal device 1 is used to request to join the multicast group 1, and the multicast ACL includes the multicast address of the multicast group 1, the terminal device allows to join the multicast group 1, and can use the multicast group 1 to perform multicast communication; otherwise, the multicast ACL does not include the multicast address of the multicast group 1, and then the terminal device is not allowed to join the multicast group 1, cannot join the multicast group 1, and cannot perform multicast communication using the multicast group 1.

In one possible implementation, the multicast ACL includes only multicast addresses of one or more multicast groups that the end device is not allowed to join. In this way, the multicast ACL may be understood as a blacklist, that is, a list of multicast groups that the terminal device is not allowed to join, or the terminal device cannot use the multicast group included in the multicast ACL for multicast communication. If the IGMP message sent by the terminal device 1 is used to request to join the multicast group 1, and the multicast ACL includes the multicast address of the multicast group 1, the terminal device 1 cannot join the multicast group 1.

In one possible implementation, the multicast ACL includes indication information of a multicast group that the terminal device allows to join and indication information of a multicast group that the terminal device does not allow to join.

(2) In the embodiment of the present application, the routing rule information includes a first type of routing rule and a second type of routing rule. The first type of routing rule includes a routing rule for processing an IGMP packet. The second type of routing rule includes a routing rule corresponding to a multicast address of a multicast group allowed to join by the terminal device.

The routing rule is used for detecting and forwarding a data packet, and includes a PDR and a FAR associated with the PDR, and optionally, a QoS Enforcement Rule (QER) and a statistical information reporting rule (URR) associated with the PDR. The PDR is used for matching with the characteristic information of the message and searching the PDR matched with the message. The FAR is used for realizing operations such as forwarding of messages.

The routing rules for handling IGMP packets include one or more PDRs and FARs associated with the corresponding PDRs. A PDR in the routing rule for processing the IGMP message is used for detecting the IGMP message which comes from the terminal equipment and is used for requesting to join or quit a certain multicast group, and a FAR associated with the PDR matched with the IGMP message is used for indicating the terminal equipment to allow to join the multicast group and indicating the UPF network element to set the state of the routing rule corresponding to the multicast address of the multicast group in the second type of routing rule as an activated state; or, the UPF network element is configured to instruct the terminal device to exit the multicast group and instruct the UPF network element to set the state of the routing rule corresponding to the multicast address of the multicast group in the second type of routing rule as a deactivated state; or, the method and the device are used for indicating that the terminal device is not allowed to join the multicast group.

And the PDR in the routing rule corresponding to the multicast address of the multicast group in the second type of routing rule is used for matching with the characteristic information of the multicast message, searching the PDR matched with the multicast message, and using the FAR associated with the PDR to control the forwarding of the multicast message.

It can be understood that the routing rule for processing the IGMP packet is used to indicate that the state of the routing rule corresponding to the multicast address of a specific multicast group in the second type of routing rule is set to an activated state or a deactivated state, and the specific multicast group is a multicast group requested to join or leave by the IGMP packet of the terminal device.

It should be noted that, in the embodiment of the present application, the activated state may also be described as an activated state; the deactivated state may also be described as a deactivated state, an inactivated state, or the like. The data packet and the message in the embodiment of the application have the same meaning and can be replaced mutually. The IGMP message and the IGMP message in the embodiment of the application have the same meaning and can be replaced mutually. In this embodiment of the present application, the routing rule corresponding to the multicast address of the multicast group may be described as a routing rule corresponding to the multicast group or a routing rule corresponding to the multicast address.

5. Internal interface of UPF network element

In this embodiment of the present application, the internal interface of the UPF network element is a virtual port or a specific port in the UPF network element, and is used for the UPF network element to locally forward the received data packet. The local forwarding to the internal interface of the UPF network element means that the UPF network element receives the data packet again at the internal interface, so that the data packet is detected by the UPF network element again, and is then matched with the corresponding routing rule and forwarded to the correct path. The UPF network element may decapsulate the packet with an external tunnel header prior to re-detection. Optionally, new outer tunnel header information may be further encapsulated for the data packet, and the new tunnel information may be included in the FAR of the routing rule, or generated by the UPF network element according to the forwarding indication information in the FAR, which is not limited herein.

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Where in the description of the present application, "/" indicates a relationship where the objects associated before and after are an "or", unless otherwise stated, for example, a/B may indicate a or B; in the present application, "and/or" is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone, wherein A and B can be singular or plural. Also, in the description of the present application, "a plurality" means two or more than two unless otherwise specified. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In addition, in order to facilitate clear description of technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items having substantially the same functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance. Also, in the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion for ease of understanding.

Currently, third generation partnership (3)^rd-generation partnership project, 3GPP) Technical Standard (TS) 29.244 defines the way in which the user plane forwards packets, and the architecture is shown in fig. 5. The working mechanism is that after receiving a message from an entrance (such as an N3 interface), the UPF network element determines a session to which the message belongs according to a user plane protocol label (such as a Tunnel End Identifier (TEID)) of the message. The UPF network element then matches the Packet Detection Rule (PDR) (possibly one or more) in the N4 session context (N4 session context) of the session with the characteristic information of the packet, finding a PDR that matches it. The PDR specifies a Forwarding Action Rule (FAR), a QoS Enforcement Rule (QER), and a statistical information reporting rule (URR) corresponding to the packet. And the UPF network element may perform drop (drop), forward (forward), buffer (buffer), and report control plane (notify) or duplicate (duplicate) operations on the packet according to the FAR. The UPF network element may perform statistics information reporting on the message according to the URR. Finally, the message is sent out of the egress (e.g., the N6 interface). The key actions include an appointed exit identifier and an exit action in the process that the UPF network element executes forwarding processing on the message according to the FAR. The egress action may include, for example, adding an outer header (outer header creation), a transport level marking (transport level marking), a forwarding policy (forwarding policy), or a header enhancement (header enhancement), etc. The message forwarding mode can be understood as a message forwarding mode for unicast communication.

However, the above-mentioned packet forwarding method is not suitable for a multicast communication scenario, and the current packet forwarding method provided for broadcast communication is also not suitable for a broadcast communication scenario. Therefore, in a multicast communication scenario, how to implement forwarding control of a multicast packet by a 5G core network is an urgent technical problem to be solved.

In view of this, embodiments of the present application provide a multicast communication method, an apparatus, and a system thereof, and in a multicast communication scenario, a 5G core network may efficiently and flexibly implement forwarding control of a multicast packet.

The technical scheme provided by the embodiment of the application can be applied to various communication systems. For example: the method and the device for scheduling Long Term Evolution (LTE) may be applied to a Long Term Evolution (LTE) system or a 5G system, and may also be applied to other new systems facing the future, for example, a programmable user plane system, which is not specifically limited in this embodiment of the present application. In addition, the term "system" may be used interchangeably with "network".

Fig. 6 is a schematic diagram of a network architecture to which the embodiments of the present application are applied. The network architecture shown in fig. 6 comprises a session management network element 601 and a user plane network element 602. The session management network element 601 and the user plane network element 602 may communicate directly or may communicate through forwarding of other devices, which is not specifically limited in this embodiment of the present application.

In this embodiment of the present application, the session management network element 601 is configured to, in a process of establishing a PDU session of a terminal device, acquire multicast access control information (i.e., a multicast ACL) of the terminal device, where the multicast access control information includes indication information of whether the terminal device is allowed to join one or more multicast groups; setting routing rule information according to the multicast access control information; the routing rule information is sent to the user plane network element 602. The routing rule information includes a first type routing rule and a second type routing rule, the first type routing rule is a routing rule for processing an IGMP packet, and the second type routing rule includes a routing rule corresponding to a multicast address of a multicast group that the terminal device allows to join.

The session management network element 601 may set the first type of routing rule and the second type of routing rule according to the multicast access control information, and set a state of the routing rule included in the second type of routing rule as a deactivated state.

When setting the first type of routing rule, the session management network element 601 may include:

(1) and setting a first PDR matched with the first IGMP packet and a FAR associated with the first PDR for a first IGMP packet which is used by the terminal device to request to join the first multicast group, wherein the FAR associated with the first PDR indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element 602 to set the state of the routing rule corresponding to the first multicast group in the second type of routing rule to an activated state, and the first multicast group is a multicast group which is allowed to join the terminal device in the one or more multicast groups. Then the routing rules for processing IGMP packets include the first PDR and the FAR associated with the first PDR.

The session management network element may set a value of a specified field in the FAR associated with the first PDR to a first value, so as to indicate that the terminal device is allowed to join the first multicast group and indicate the user plane network element 602 to set a state of a routing rule corresponding to the first multicast group in the second type of routing rule to an active state.

(2) And setting a second PDR matched with the second IGMP packet and a FAR associated with the second PDR for a second IGMP packet used by the terminal device to request to exit the first multicast group, where the FAR associated with the second PDR indicates that the terminal device exits the first multicast group and indicates the user plane network element 602 to set the state of the routing rule corresponding to the first multicast group in the second type of routing rule to a deactivated state. Then the routing rules for processing IGMP packets include the second PDR and the FAR associated with the second PDR.

The session management network element may set a value of a specified field in the FAR associated with the second PDR to a second value, so as to instruct the terminal device to exit the first multicast group and instruct the user plane network element 602 to set a state of a routing rule corresponding to the first multicast group in the second type of routing rule to a deactivated state.

(3) Setting a third PDR matched with the third IGMP message and a FAR associated with the third PDR aiming at a third IGMP message used for requesting to join the second multicast group by the terminal equipment, wherein the FAR associated with the third PDR indicates that the terminal equipment is not allowed to join the second multicast group; wherein the second multicast group is a multicast group that the terminal device is not allowed to join in one or more multicast groups. Then the routing rules for processing IGMP packets include a third PDR and the FAR associated with the third PDR.

The session management network element may set a value of a specified field in the FAR associated with the third PDR to a third value, so as to indicate that the terminal device is not allowed to join the second multicast group.

In the above (1) to (3), the specified field may be an "action" field, the first value may be a "5G LAN multicast join accept", the second value may be a "5G LAN multicast leave accept", and the third value may be a "5G LAN multicast join deny".

The activation state or the deactivation state may be indicated in one or more of the following three ways.

In a first manner, the deactivated state or the activated state may be indicated by the state indication information in the routing rule corresponding to the multicast group.

When setting the second type routing rule, the session management network element 601 may include: and setting the state indication information in each routing rule in the second class of routing rules to be in a deactivation state. For example, in an IPTV scenario, the user plane network element 602 receives video resources issued by a multicast channel provider, when a terminal device does not join the multicast channel 1, a routing rule corresponding to the multicast group 1 corresponding to the multicast channel 1 is in a deactivated state, the user plane network element 602 does not issue the video resources to the terminal device in the multicast group 1, and when the terminal device requests to join through the first IGMP packet and the terminal device allows to join the multicast group 1, the user plane network element 602 sets the routing rule corresponding to the multicast group 1 to an activated state, and then issues the video resources to the terminal device in the multicast group 1, so as to save resources.

In a second mode, the deactivation state or the activation state may be indicated by a bitmap.

When sending routing rule information to the user plane network element 602, the session management network element 601 may send a bitmap associated with the second type of routing rule to the user plane network element 602 together. In a possible implementation, the second type of routing rule further includes an associated bitmap. The bitmap may be included in a routing rule corresponding to any one of the multicast groups in the second type of routing rule. The bitmap includes N bits, N being a natural number; any bit in the bitmap has a mapping relationship with a multicast address of a multicast group of the one or more multicast groups. The value of the bit is a first preset value, for example, 0, and is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivated state; the value of the bit is a second preset value, for example, "1", which is used to indicate that the routing rule corresponding to the multicast address corresponding to the bit is in an active state. For example, the multicast access control information obtained by the session management network element 601 includes that the UE1 is allowed to join the multicast groups 1 and 2, and the UE1 is not allowed to join the multicast group 3, the bitmap generated by the session management network element 601 may include 3 bits, where a first bit has a mapping relationship with the multicast address of the multicast group 1, a second bit has a mapping relationship with the multicast address of the multicast group 2, and a third bit has a mapping relationship with the multicast address of the multicast group 3, and the session management network element 601 sets the values of the first bit and the second bit to "1" and the third bit to "0" in the bitmap.

The session management network element 601 may send a mapping relationship to the user plane network element 602, and the mapping relationship may also be preconfigured on the user plane network element 602.

In a third manner, the deactivation state or the activation state may be indicated by activating the member list AML.

AML is used to indicate multicast groups for which routing rules are active. The AML may include one or more multicast addresses or may be null. The AML includes one or more multicast addresses, which may indicate that a routing rule corresponding to any one of the one or more multicast addresses is active. The AML is null, which may indicate that the routing rule corresponding to any multicast address allowed to be added by the terminal device is in a deactivated state. When sending the routing rule information to the user plane network element 602, the session management network element 601 may send the AML associated with the second type of routing rule to the user plane network element 602 together. In a possible implementation, the routing rules of the second type further include associated AMLs. Specifically, the session management network element 601 sets AML to null and sends it to the user plane network element 602. When a subsequent terminal device requests to join a specified multicast group X, and the multicast group X is a multicast group that the terminal device allows to join, the user plane network element 602 adds the multicast address of the multicast group X into the AML.

Accordingly, the user plane network element 602 receives the routing rule information from the session management network element 601. The user plane network element 602, when receiving a first IGMP packet from a terminal device for requesting to join a first multicast group, determines whether the first multicast group is any one multicast group that the terminal device is allowed to join in the one or more multicast groups, and sets a state of a routing rule corresponding to the first multicast group in a second type of routing rule to an active state if the first IGMP packet is determined to be allowed to join in the one or more multicast groups.

The user plane network element 602 matches the first IGMP packet with the first class of routing rules, determines a first PDR matching the first IGMP packet and a FAR associated with the first PDR from the first class of routing rules, where an assigned field in the FAR associated with the first PDR is a first value, indicates that the terminal device is allowed to join the first multicast group, and indicates that the user plane network element 602 sets the state of the routing rule corresponding to the first multicast group in the second class of routing rules to an activated state.

After the user plane network element 602 sets the routing rule corresponding to the first multicast group to the activated state, if a second IGMP packet, which is used to request to exit the first multicast group, is received from the terminal device, it is determined that the terminal device exits the first multicast group according to the first class of routing rules, and the routing rule corresponding to the first multicast group in the second class of routing rules is set to the deactivated state. Specifically, the user plane network element 602 matches the second IGMP packet with the first class of routing rules, and further determines, from the first class of routing rules, a second PDR matched with the second IGMP packet and a FAR associated with the second PDR, where a specified field in the FAR associated with the second PDR is a second value, and instructs the terminal device to exit the first multicast group and instructs the user plane network element 602 to set the state of the routing rule corresponding to the first multicast group in the second class of routing rules to the deactivated state.

When receiving a third IGMP packet from the terminal device for requesting to join the second multicast group, the user plane network element 602 matches the third IGMP packet with the first routing rule, and further determines a third PDR matching the third IGMP packet and a FAR associated with the third PDR from the first routing rule, where a specified field in the FAR associated with the third PDR is a second value, and indicates that the terminal device is not allowed to join the second multicast group.

Subsequently, when the user plane network element 602 receives the multicast packet, in the process of searching for the routing rule matching the multicast packet in the second type of routing rule, the routing rule in the deactivated state is skipped over, and the routing rule in the activated state is directly matched with the multicast packet, so that the matching efficiency can be improved.

In one manner, for the case that the deactivation state or the activation state can be indicated by using a bitmap, when the user plane network element 602 receives a multicast packet, the bit with the value of the first preset value in the bitmap is skipped over, the multicast address corresponding to the bit with the value of the second preset value in the bitmap is determined according to the mapping relationship, and the routing rule corresponding to the multicast address corresponding to the bit with the value of the second preset value is matched with the received multicast packet, so that the matching efficiency can be improved.

In another way, for the case that the deactivation state or the activation state can be indicated by a bitmap, when the user plane network element 602 receives a multicast packet, the multicast address corresponding to each bit in the bitmap is determined according to the mapping relationship, the routing rule of the multicast address corresponding to the bit with the value of the first preset value is skipped over, and the routing rule of the multicast address corresponding to the bit with the value of the second preset value is matched with the received multicast packet, so that the matching efficiency can be improved.

For the case that the deactivation state or the activation state can be indicated through AML, the user plane network element 602 matches the multicast packet with the multicast address included in AML when receiving the multicast packet, and determines the routing rule matched with the multicast packet, thereby improving the matching efficiency.

The session management network element 601 may send the routing rule information to the user plane network element 602 through an N4 session message at the user level, i.e. send the routing rule information through an N4 session message corresponding to the PDU session of the terminal device. When the session management network element 601 determines that the user plane network element 602 provides service for the 5G LAN group to which the terminal device belongs for the first time, it determines the N4 session corresponding to the 5G LAN group, and sends the routing rule information to the user plane network element 602 through the N4 session message corresponding to the 5G LAN group.

The user plane network element 602 may send an N4 report to the session management network element 601 in case the terminal device joins or exits the first multicast group, the N4 report indicating that the terminal device joined or exited the first multicast group. The session management network element 601 may update the routing rules corresponding to the first multicast group in the N4 session at the group level corresponding to the 5G LAN group for the user plane network element 602 and/or other user plane network elements according to the N4 report; and sending the updated routing rule corresponding to the first multicast group in the N4 session at the group level to the user plane network element and/or other user plane network elements, so that the user plane network element providing service for the 5G LAN group can acquire the updated routing rule corresponding to the first multicast group in the N4 session at the group level, and further control the forwarding of the multicast message.

Example 1, assume that end device 1 is allowed to join multicast groups 1-3. The session management network element 601 sets routing rule information according to the multicast ACL and sends the routing rule information to the user plane network element 602 in the process of establishing PDU session 1 by the terminal device 1. The routing rule information comprises a first class of routing rules and a second class of routing rules, and the states of the routing rules corresponding to 3 multicast groups in the second class of routing rules are all deactivated states. When receiving a first IGMP packet requesting to join the multicast group 2 from the terminal device 1, the user plane network element 602 matches the first IGMP with the first class of routing rules, and matches the first IGMP with the first class of routing rules, where a specified field in an FAR associated with the first PDR is a first value, then the terminal device 1 allows to join the multicast group 2, and the user plane network element 602 sets a routing rule corresponding to the multicast group 2 in the second class of routing rules to an active state, that is, updates the inactive state to the active state. Then, the terminal device 1 may receive a multicast packet, such as "hello", of the multicast group 2, and the user plane network element 602 may search a routing rule matching the multicast packet according to the routing rule corresponding to the multicast group 2, and forward the "hello" to the terminal device 1 according to the routing rule.

Assuming that the network architecture shown in fig. 6 is applied to the 5G network shown in fig. 1, a network element or entity corresponding to the session management network element 601 may be an SMF network element in the 5G network, and a network element or entity corresponding to the user plane network element 602 may be a UPF network element in the 5G network. The network architecture shown in fig. 6 may also include the PCF network element, UDM network element, and NEF network element shown in fig. 1. In the subsequent embodiment of the method, the session management network element 601 takes an SMF network element as an example, the user plane network element 602 takes an UPF network element as an example, and the terminal device takes a UE as an example.

The multicast communication method provided in the embodiment of the present application is described in detail based on the network architecture shown in fig. 1 or fig. 6. It should be noted that, in the embodiment of the present application, an interactive manner is adopted to introduce a multicast communication method, and names of interactive messages or information between network elements are used for example, and do not form a limitation to the embodiment of the present application.

Referring to fig. 7, a flowchart of a multicast communication method according to an embodiment of the present application is shown, where the method includes the following steps:

in step 301, the UE1 sends a PDU session setup request to the SMF network element. Accordingly, the SMF network element receives a PDU session setup request from the UE 1.

The UE1 may be any one of the terminal devices in the 5G LAN group 1. The embodiments of the present application are applicable to multicast communication scenarios, where the UE1 may join one or more multicast groups. For example, in an IPTV scenario, the UE1 may join one or more multicast channels.

The UE1 sends a PDU session setup request to the SMF network element in case a PDU session needs to be established. For example, the SMF network element may send a PDU session setup request to the SMF network element through the access network device and the AMF network element.

Step 302, the SMF network element obtains multicast access control information of the UE 1.

The SMF network element obtains multicast access control information of the UE1 in case of receiving the PDU session setup request. If the multicast access control information is the white list, the SMF network element obtains the group information of the multicast group that the UE1 allows to join. If the multicast access control information is a blacklist, the SMF network element obtains group information of a multicast group that the UE1 does not allow to join, for example, in an IPTV scenario, the UE1 only purchases the viewing right of some basic multicast channels, and does not purchase the viewing right of a special multicast channel, so the UE1 cannot view the special multicast channel.

The group information of the multicast group may include a multicast address and/or a multicast member identification list, where the multicast member identification list includes identifications of multicast members that can join the multicast group, and the identifications of the multicast members may be addresses of UEs or user IDs or General public user identifiers (GPSIs). Optionally, the group information of the multicast group further includes an identifier of the multicast group. For example, assuming that the UE1, the UE2, and the UE3 may join the multicast group 1, the group information of the multicast group 1 includes a multicast address of the multicast group 1, and identifications of the UE1, the UE2, and the UE3, and optionally further includes a group identification of the multicast group 1, which may be represented as { group identification, multicast address, { UE1 ID, UE2 ID, UE3 ID }.

Optionally, the multicast access control information of the UE1 further includes a 5G LAN group ID to which the UE1 belongs and a Data Network Name (DNN) associated with the 5G LAN (i.e., a name of a DN connected to the 5G LAN group). The multicast access control information may be expressed as 5G LAN group ID, DNN, { group identification, multicast address, { UE ID } }. It will be appreciated that a 5G LAN group may include one or more multicast groups, and a multicast group may include one or more multicast members.

The SMF network element may obtain the multicast access control information of the UE1 in one or more ways, which may be referred to as a schematic diagram of obtaining the multicast access control information shown in fig. 8.

In the first mode, the SMF network element locally obtains the multicast access control information of the UE 1. The SMF network element is configured with a plurality of multicast access control information locally, and upon receiving a PDU session establishment request from the UE1, searches for the multicast access control information of the UE1 from the plurality of multicast access control information according to the identifier of the UE 1. For example, the SMF network element matches the identifier of the UE1 with the { UE ID } of multiple pieces of multicast access control information, and if the identifier of the UE1 is included in the { UE ID } of a certain piece of multicast access control information, the multicast access control information may be used as the multicast access control information of the UE 1.

In the second mode, the SMF network element obtains the multicast access control information of the UE1 from the UDM network element, for example, the multicast access control information of the UE1 may be obtained from the UDM network element through a subscription data process. The SMF network element sends a signing data acquisition request to the UDM network element, wherein the signing data acquisition request can carry an identifier of the UE 1; and under the condition that the UDM network element receives the subscription data acquisition request, extracting subscription data of the UE1 according to the identity of the UE1, and sending a subscription data acquisition response to the SMF network element, wherein the subscription data acquisition response comprises the subscription data of the UE1, and the subscription data of the UE1 comprises multicast access control information of the UE 1. The AF network element may issue a plurality of multicast access control information to the UDM network element, so that the UDM network element may feed back the multicast access control information of the UE1 to the SMF network element. The AF network element can directly issue a plurality of multicast access control information to the UDM network element, or issue a plurality of multicast access control information to the UDM network element through the NEF network element.

In a third mode, the SMF network element obtains the multicast access control information of the UE1 from a data network authentication authorization accounting (DN-AAA), for example, the multicast access control information of the UE1 may be obtained from the DN-AAA through a secondary authentication process, and the multicast access control information of the UE1 may be carried in authentication data of the secondary authentication. During the process of establishing the PDU session, the UE1 may be authenticated secondarily by the DN-AAA, and the first authentication process may be understood as a process in which the AUSF network element authenticates the UE 1.

In a fourth mode, the SMF network element obtains the multicast access control information of the UE1 from the PCF network element, for example, the SMF network element may obtain the multicast access control information of the UE1 from the PCF network element through a policy data obtaining process. The SMF network element sends a policy data acquisition request to the PCF network element, wherein the policy data acquisition request can carry an identifier of the UE 1; the PCF network element, upon receiving the policy data acquisition request, extracts policy data of the UE1 according to the identity of the UE1, and sends a policy data acquisition response to the SMF network element, where the policy data acquisition response includes policy data of the UE1, and the policy data of the UE1 may be a Policy and Charging Control (PCC) rule, including multicast access control information of the UE 1. The AF network element may issue a plurality of multicast access control information to the PCF network element, so that the PCF network element may feed back the multicast access control information of the UE1 to the SMF network element. The AF network element can directly issue a plurality of multicast access control information to the PCF network element, or issue a plurality of multicast access control information to the PCF network element through the NEF network element.

Step 303, the SMF network element sets routing rule information according to the multicast access control information of the UE 1.

The SMF network element may set routing rule information according to the multicast access control information of the UE1, when acquiring the multicast access control information of the UE 1. Specifically, the first type routing rule and the second type routing rule are set according to the multicast access control information of the UE1, and the state of the routing rule included in the second type routing rule is set to the deactivated state. The first type of routing rule may include one or more sets of routing rules for processing IGMP packets, and the second type of routing rule may include one or more sets of routing rules corresponding to multicast groups. Each set of routing rules includes a PDR and a FAR associated with the PDR. Optionally, each set of routing rules may further include QER and URR associated with the PDR.

When the SMF network element sets the first type of routing rule, the method may include:

(1) and for a first IGMP message used by the UE1 for requesting to join the first multicast group, setting a first PDR matched with the first IGMP message and a FAR associated with the first PDR, wherein the FAR associated with the first PDR indicates that the UE1 allows to join the first multicast group and indicates that the UPF network element 1 sets the state of a routing rule corresponding to the first multicast group in the second type of routing rules to an activated state, and the first multicast group is a multicast group which allows the UE1 to join in the one or more multicast groups. Then the routing rules for processing IGMP packets include the first PDR and the FAR associated with the first PDR.

The SMF network element may set a value of a specified field in the FAR associated with the first PDR to a first value, so as to indicate that the UE1 is allowed to join the first multicast group and indicate that the UPF network element 1 sets the state of the routing rule corresponding to the first multicast group in the second type of routing rule to an activated state.

(2) And for a second IGMP message used by the UE1 to request to exit the first multicast group, setting a second PDR matched with the second IGMP message and a FAR associated with the second PDR, where the FAR associated with the second PDR indicates that the UE1 exits the first multicast group and indicates that the UPF network element 1 sets the state of the routing rule corresponding to the first multicast group in the second class of routing rules to a deactivated state. Then the routing rules for processing IGMP packets include the second PDR and the FAR associated with the second PDR.

The SMF network element may set a value of a specified field in the FAR associated with the second PDR to a second value, so as to instruct the UE1 to exit the first multicast group and instruct the UPF network element 1 to set the state of the routing rule corresponding to the first multicast group in the second type of routing rule to a deactivated state.

(3) Setting a third PDR matched with the third IGMP packet and a FAR associated with the third PDR for a third IGMP packet used by the UE1 to request to join the second multicast group, wherein the FAR associated with the third PDR indicates that the UE1 is not allowed to join the second multicast group; wherein the second multicast group is a multicast group to which the UE1 is not allowed to join in one or more multicast groups. Then the routing rules for processing IGMP packets include a third PDR and the FAR associated with the third PDR.

The SMF network element may set a value of a specified field in the FAR associated with the third PDR to a third value to indicate that the UE1 is not allowed to join the second multicast group.

Optionally, the routing rule for processing the IGMP packet may carry multicast access control information of the UE1, so that the UPF network element 1 may obtain the multicast access control information of the UE 1.

Optionally, the routing rule for processing the IGMP packet further includes creation indication information, which is used to indicate the UPF network element 1 to create or delete the routing rule corresponding to the specified multicast group, where the specified multicast group is a multicast group to which the IGMP packet requests to join or leave. For example, the UE1 sends a first IGMP message for requesting to join the designated multicast group, and the UPF network element 1 creates a routing rule corresponding to the designated multicast group if it is determined that the UE1 allows to join the designated multicast group. For another example, the UE1 sends a second IGMP message for requesting to exit the designated multicast group, so that the UPF network element 1 deletes the routing rule corresponding to the designated multicast group when determining that the UE1 exits the designated multicast group.

When the SMF network element sets the second type of routing rule, the method may include: and setting the state indication information in each routing rule in the second class of routing rules to be in a deactivation state.

Illustratively, the UE1 is allowed to join multicast group 1 and multicast group 2, and the SMF network element sets the first type of routing rule and the second type of routing rule. The first type of routing rule includes a routing rule for processing an IGMP packet for the multicast group 1 and a routing rule for processing an IGMP packet for the multicast group 2. The routing rule for multicast group 1 to process IGMP packets may include a FAR associated with a first PDR and a first PDR matching a first IGMP packet requesting to join multicast group 1, or a FAR associated with a second PDR and a second PDR matching a second IGMP packet requesting to leave multicast group 1, or a FAR associated with a third PDR and a first PDR matching a third IGMP packet requesting to join multicast group 3 (a multicast group that UE1 does not allow to join). The second type of routing rule includes a routing rule corresponding to the multicast group 1 and a routing rule corresponding to the multicast group 2, and the state indication information in the routing rule corresponding to the multicast group 1 indicates a deactivation state.

The SMF network element may set the routing rule information in the user level N4 session and may also set the routing rule information in the group level N4 session.

Routing rule information in N4 session at (a) user level

The SMF network element sets the routing rule information in the N4 session at the user level in the process of establishing the PDU session of the UE 1. The routing rule information in the user-level N4 session may include a first type of routing rule and a second type of routing rule. For the routing rule corresponding to any multicast group in the second type of routing rule in the N4 session at the user level, the routing rule includes a DL PDR and a DL FAR associated with the DL PDR, and optionally further includes a DL URR and a DL QER corresponding to the DL PDR.

The UL PDR in the current user level N4 session is used to detect the unicast packet received from the PDU session tunnel, and specifically may include: source interface parameters, tunnel information parameters, network instance information, and filter parameters or addresses of terminal devices. The source interface parameter is set to "access network side" or "core network side". The tunnel information parameter is set as a tunnel General Packet Radio Service (GPRS) tunnel protocol user plane (GTP-U) TEID of a PDU session at the UPF network element side. The network instance information is set to a value corresponding to the 5G LAN group, i.e., identifying the 5G LAN group to which the terminal device belongs. The filter parameters may use, for example, the address of the terminal device as the source address. The address of the terminal device may include an IP address or a MAC address, which is described herein in a unified manner and will not be described in detail below.

The UL FAR corresponding to the UL PDR includes network instance information and target interface parameters, and is used for transmitting the data packet matched with the UL PDR to the target interface. The SMF network element sets the network instance information to a value corresponding to the 5G LAN group, and the value of the target interface parameter is set to a value corresponding to the internal interface of the UPF network element (for example, "5G VN internal"). It will be appreciated that the UL FAR in the N4 session at the user level is used to forward locally to the internal interface of the UPF network element the packets received from the PDU session tunnel that match the UL PDR in this N4 session.

The DL PDR in the current user level N4 session is used to detect unicast packets received from the internal interface, including in particular source interface parameters, network instance information, and filter parameters or the address of the end device. Wherein, the source interface parameter is set as '5G VN internal'; the network instance information is set to a value corresponding to the 5G VN group; the filter parameters may for example use the address of the terminal device as the target address.

The DL FAR corresponding to the DL PDR includes network instance information, target interface parameters, and/or parameters of the external tunnel, and is used to transmit the data packet received from the internal interface and matched with the DL PDR to the target interface. Wherein, the network instance information is set to a value corresponding to the 5G VN group; the value of the target interface parameter is set as an access network side (access side) or a core network side (core side); the value of the parameter of the external tunnel is set as the tunnel information of the PDU session (for example, GTP-U teid of the PDU session on the access network device or the UPF network element. it can be understood that DL FAR in N4 session corresponding to the PDU session is used to transmit the data packet received from the internal interface matching the DL PDR in the N4 session to the specified PDU session tunnel.

On the basis of the content included in the DL PDR for the unicast message, the message copy information and the continuous matching indication information are added to the DL PDR for processing the broadcast message, and the filter parameter uses the broadcast address as the target address. The message replication information may be an address of the sender UE, and the continuous matching indication information allows the UPF network element to continue to search for other PDRs after successfully matching the DL PDR in the PDR search process without stopping the PDR search process. If the UPF network element receives the broadcast message from the PDU session of the UE, the broadcast message is forwarded to the internal interface according to the UL PDR and the UL FAR in the N4 session of the user level, then the UPF network element searches all DL PDRs of the detection broadcast message matched with the broadcast message on the internal interface, if the DL DPR is successfully matched, and if the message copying information of the DL PDR is the same as the source address of the broadcast message, the UPF network element skips the FAR/QER/URR and other processing corresponding to the DL PDR; when the message copying information of the DL PDR is different from the source address of the broadcast message, the UPF network element copies the broadcast message, and FAR/QER/URR and the like corresponding to the DL PDR are used for processing the copied broadcast message; and then the UPF network element matches the original broadcast message with other unmatched DL PDRs according to the continuous matching indication information.

In the embodiment of the present application, a DL PDR in a multicast communication scenario is introduced, where the DL PDR is used to detect a multicast packet received by an internal interface, and may specifically include one or more of status indication information, internal interface parameters, network instance information, a multicast address, packet replication information, and continuation matching indication information. The state indication information is used to indicate whether the DL PDR is in an activated state or a deactivated state, and the deactivated state may also be described as an inactivated state or a state to be activated. The internal interface parameter is set to a value corresponding to the internal interface of the UPF network element, for example, "5G VN internal". The network instance information is set to a value corresponding to the 5G LAN group. The multicast address is used for matching with the multicast address carried by the multicast message. The message replication information refers to an address of the terminal device, specifically, an address of a multicast source, and the UPF network element replicates a multicast message sent by the multicast source, so as to send the multicast message to a corresponding multicast member. And the continuous matching indication information is used for indicating the UPF network element to continue to match other unmatched PDRs if a matched PDR is found in the PDR searching process without stopping matching. It can be understood that, in the embodiment of the present application, the content included in the DL PDR of the user-level N4 session is added with the status indication information on the basis of the content included in the DL PDR for the broadcast packet, and the broadcast address is replaced with the multicast address.

In this embodiment of the present application, the DL FAR corresponding to the DL PDR includes tunnel information of the PDU session, for example, a GTP-U TEID of the PDU session on the access network device or the UPF network element, and is used to transmit the multicast packet received from inside and matched with the DL PDR to a specified PDU session tunnel. Optionally, the DL FAR corresponding to the DL PDR further includes network instance information, which is set to a value corresponding to the 5G LAN group.

Routing rule information in (two) group level N4 sessions

And when determining that the UPF network element 1 provides service for the 5G LAN group 1 for the first time, the SMF network element determines the N4 session corresponding to the 5G LAN group 1, and sets the routing rule information in the N4 session at the group level corresponding to the 5G LAN group 1. For example, in fig. 4b, it is assumed that the UPF network element 1 provides service for the 5G LAN group 1 for the first time, and the N4 session corresponding to the 5G LAN group 1 is N4 session 4. The routing rule information in the group-level N4 session may include a first type of routing rule and a second type of routing rule.

For a routing rule corresponding to any multicast group in the second type of routing rule in the group-level N4 session, the routing rule includes a DL PDR and a DL FAR associated with the DL PDR, and optionally further includes a DL URR and a DL QER corresponding to the DL PDR; or include UL PDR and UL FAR associated with the UL PDR, and optionally further include UL URR and UL QER corresponding to the UL PDR.

The UL PDR in the current group level N4 session is used to detect unicast packets received from the internal interface, and may specifically include source interface parameters, network instance information, and filter parameters. Wherein, the source interface parameter is set as '5G VN internal'; the network instance information is set to a value corresponding to the 5G LAN group, and the filter parameter may use, for example, the address of the terminal device as the destination address.

The UL FAR associated with the UL PDR includes network instance information, target interface parameters, and/or parameters of the external tunnel for forwarding packets received from the internal interface that match the UL PDR to the target interface. Wherein, the network instance information is set to a value corresponding to the 5G LAN group; the value of the target interface parameter is set as 'core side'; the value of the parameter of the external tunnel is set as the information of the N19 tunnel (for example, the GTP-U TEID of the N19 tunnel of the other UPF network element connected with the current UPF network element) or the N6 interface. It will be appreciated that the UL FAR in the group level N4 session is used to forward packets matching the UL PDR in the group level N4 session to the N19 tunnel where the UPF network element is connected to other UPF network elements or the N6 interface where the UPF network element is connected to a DN.

On the basis of the content included in the UL PDR aiming at the unicast message, message copy information and continuous matching indication information are added to the UL PDR for processing the broadcast message, and meanwhile, the broadcast address is used as the target address by the filter parameter. The message replication information may be N19 indication information or N6 indication information, and the continuous matching indication information allows the UPF network element to continue to search for other PDRs after successfully matching the UL PDR in the PDR searching process, without stopping the PDR searching process. If the UPF network element receives the broadcast message from the N19 tunnel, the broadcast message and the N19 indication information are forwarded to the internal interface together according to the DL PDR and the DL FAR in the N4 conversation of the group level, then the UPF network element searches all UL PDRs of the detection broadcast message matched with the broadcast message on the internal interface, if the UL DPR is successfully matched, if the message replication information of the UL PDR is the same as the N19 indication information of the broadcast message, the UPF network element skips the FAR/QER/URR and other processes corresponding to the UL PDR; when the message copying information of the UL PDR is different from the N19 indicating information of the broadcast message, copying the broadcast message by the UPF network element, and processing and copying the obtained broadcast message by using FAR/QER/URR and the like corresponding to the UL PDR; and then the UPF network element matches the original broadcast message with other unmatched UL PDRs according to the continuous matching indication information.

In the embodiment of the present application, a UL PDR in a multicast communication scenario is introduced, where the UL PDR is used to detect a multicast packet received from an internal interface, and may specifically include internal interface parameters, network instance information, a multicast address, and packet replication information, which may be referred to as a UL PDR used to detect a broadcast packet. For the description of the UL FAR corresponding to the UL PDR, reference may be made to the UL FAR corresponding to the UL PDR for detecting the broadcast packet, which is not described herein again.

The DL PDR in the current group level N4 session is used to detect unicast packets received from the N19 tunnel or N6 interface, including specifically source interface parameters, network instance information, and/or tunnel information parameters. Wherein, the source interface parameter is set as '5G VN internal'; the network instance information is set to a value corresponding to the 5G LAN group; the tunnel information parameter is set as GTP-U TEID of the N19 tunnel on the UPF network element side.

The DL FAR corresponding to the DL PDR includes internal interface parameters for transmitting the packet received from the N19 tunnel or N6 interface, which is matched with the DL PDR, to the internal interface. The SMF network element sets the value of the internal interface parameter to a value (e.g., "5 GVN internal") corresponding to the internal interface of the UPF network element. It will be appreciated that the DL FAR in the group level N4 session is used to forward packets matching the DL PDR in the group level N4 session locally to the internal interface of the UPF network element.

On the basis of the content included by the DL PDR/FAR aiming at the unicast message, a broadcast address is added for the DL PDR processing the broadcast message, and the DL FAR adds message forwarding indication information (N19 indication information or N6 indication information), so that when the UPF forwards the broadcast message received from the N19 tunnel or the N6 interface to the internal interface, the N19 indication information or the N6 indication information is added into the tunnel header.

In the embodiment of the present application, a DL PDR in a multicast communication scenario is introduced, where the DL PDR is used to detect a multicast packet received from an N19 tunnel or an N6 interface, and may specifically include state indication information, tunnel parameter information, network instance information, and a multicast address. Wherein the status indication information is used for indicating whether the DL PDR is in an activated state or a deactivated state; the network instance information is set to a value corresponding to the 5G LAN group; the tunnel information parameter is set as GTP-U TEID or N6 interface of the N19 tunnel on the UPF network element side. The DL FAR corresponding to the DL PDR specifically includes internal interface parameters and N19 indication information or N6 indication information, and is used for transmitting the data packet received from the N19 tunnel or N6 interface, which is matched with the DL PDR, to the internal interface, and meanwhile, the N19 indication information or N6 indication information is added to the GTP-U tunnel header of the data packet in the forwarding process.

In the embodiment of the present application, FAR associated with RDR and FAR corresponding to PDR have the same meaning and may be replaced with each other.

When the SMF network element sends the routing rule information to the UPF network element 1, the bitmap associated with the second type of routing rule may be sent to the UPF network element 1 together. In a possible implementation, the associated bitmap is also included in the second type of routing rule. The bitmap may be included in a routing rule corresponding to any one of the multicast groups in the second type of routing rule. The bitmap includes N bits, N being a natural number; any bit in the bitmap has a mapping relationship with a multicast address of a multicast group of the one or more multicast groups. The value of the bit is a first preset value, for example, 0, and is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivated state; the value of the bit is a second preset value, for example, "1", which is used to indicate that the routing rule corresponding to the multicast address corresponding to the bit is in an active state. When the SMF network element sets the second type of routing rule, the method may include: setting the value of a bit corresponding to a multicast group which the UE1 allows to join in a bitmap as a first preset value according to the multicast access control information; and/or setting the value of the bit corresponding to the multicast group which the UE1 does not allow to join in the bitmap as a second preset value.

Illustratively, the multicast access control information obtained by the SMF network element includes that the UE1 is allowed to join the multicast groups 1 and 2, and the UE1 is not allowed to join the multicast group 3, then the bitmap generated by the SMF network element may include 3 bits, where a first bit has a mapping relationship with the multicast address of the multicast group 1, a second bit has a mapping relationship with the multicast address of the multicast group 2, and a third bit has a mapping relationship with the multicast address of the multicast group 3, and the SMF network element sets the values of the first bit and the second bit in the bitmap to "1" and sets the value of the third bit to "0".

The mapping relationship may be sent to the UPF network element 1 by the SMF network element, or may be preconfigured on the UPF network element 1.

In a third way, the deactivation state or the activation state can be indicated by AML.

The AML may include one or more multicast addresses or may be null. The AML includes one or more multicast addresses, which may indicate that a routing rule corresponding to any one of the one or more multicast addresses is active. The AML is null, which may indicate that the routing rule corresponding to any multicast address allowed to be added by the terminal device is in a deactivated state. When sending the routing rule information to the UPF network element 1, the SMF network element may send the AML associated with the second type of routing rule to the UPF network element 1 together. In a possible implementation, the routing rule of the second type further includes associated AML. Specifically, the SMF network element sets AML to null and sends it to the UPF network element 1. When the subsequent UE1 requests to join the designated multicast group X, and the multicast group X is a multicast group that the UE1 allows to join, the UPF network element 1 adds the multicast address of the multicast group X into the AML.

Step 304, the SMF network element sends routing rule information to the UPF network element 1. Accordingly, the UPF network element 1 receives the routing rule information from the SMF network element.

The routing rule information set by the SMF network element for the user-level N4 session may be sent to the UPF network element 1 through a user-level N4 session message. The N4 session message may be an N4 session establishment request or an N4 session modification request. For example, in fig. 4b, the SMF network element sends routing rule information to the UPF network element 1 via an N4 session 1 setup request.

The routing rule information set by the SMF network element for the group-level N4 session may be sent to the UPF network element 1 through a group-level N4 session message. For example, in fig. 4b, the SMF network element sends routing rule information to the UPF network element 1 via N4 session 4.

Step 305, the UE1 sends a first IGMP packet to the UPF network element 1. Accordingly, UPF network element 1 receives the first IGMP message from UE 1.

The first IGMP packet carries an address of the UE1 and a multicast address, where the multicast address is a multicast address of the UE1 requesting to join the first multicast group. The UE1 may dynamically join the first multicast group by sending a first IGMP message. The UE1 may send a first IGMP message to the UPF network element 1 through the access network device.

In step 306, the UPF network element 1 determines whether the UE1 is allowed to join the first multicast group.

And the UPF network element 1 judges whether the UE1 allows to join the first multicast group or not under the condition of receiving the first IGMP message from the UE 1.

In a possible implementation manner, the UPF network element 1 matches the multicast address carried by the received first IGMP packet with the multicast access control information of the UE1, and if the multicast address carried by the IGMP packet is included in the multicast access control information of the UE1, the UPF network element 1 may determine that the UE1 allows to join the first multicast group.

The multicast access control information of the UE1 may be carried in a routing rule for processing an IGMP packet, and specifically may be carried in a PDR for processing an IGMP packet.

In a possible implementation manner, the UPF network element 1 matches the multicast address carried by the received first IGMP packet with the routing rule for processing the IGMP packet, and if the multicast address included in a certain routing rule in the routing rule for processing the IGMP packet is the same as the multicast address carried by the first IGMP packet, the matching is successful, and the UPF network element 1 may determine that the UE1 is allowed to join the first multicast group. For example, the first IGMP packet matches the first PDR in the first type of routing rule.

Step 307, if the determination result is yes, the UPF network element 1 sets the routing rule corresponding to the first multicast group to the activated state.

And under the condition that the UPF network element 1 matches the first IGMP message with the first PDR, determining that the UE1 is allowed to join the first multicast group according to the FAR associated with the first PDR, and setting a routing rule corresponding to the first multicast group in the second type of routing rules to be in an activated state. For example, the status indication information in the routing rule corresponding to the first multicast group is set to be in an activated state.

And then, the UPF network element 1 searches a routing rule matched with the multicast message under the condition of receiving the multicast message. In the searching process, the UPF network element 1 skips over the routing rule in the deactivated state, and matches the routing rule in the activated state with the multicast message to improve the matching efficiency.

For the case where the activation state or the deactivation state is indicated by the state indication information: and if the UPF network element 1 determines that the UE1 allows to join the first multicast group, the UPF network element 1 changes the state indication information in the routing rule corresponding to the first multicast group into an activated state.

And then, under the condition that the UPF network element 1 receives the multicast message, in the process of searching the routing rule matched with the multicast message in the second class of routing rules, skipping the routing rule of which the state indication information is in a deactivation state, and matching the routing rule of which the state indication information is in an activation state with the multicast message.

For the case where the activation state or the deactivation state is indicated by a bitmap: the bit value corresponding to the first multicast group configured by the SMF network element is "0", and if the UPF network element 1 determines that the UE1 is allowed to join the first multicast group, the UPF network element 1 activates the routing rule corresponding to the first multicast group, and updates the bit value from "0" to "1".

Then, when receiving the multicast packet, in a possible implementation manner, the UPF network element 1 skips over the bit of "0" in the bitmap, determines the multicast address corresponding to the bit of "1" in the bitmap according to the mapping relationship, and matches the routing rule corresponding to the multicast address corresponding to the bit of "1" with the multicast packet. In another possible implementation manner, the UPF network element 1 determines the multicast address corresponding to the bit in the bitmap according to the mapping relationship, skips over the routing rule corresponding to the multicast address corresponding to "0", and matches the routing rule corresponding to the multicast group corresponding to "1" with the multicast packet.

For the case where the activation state or the deactivation state is indicated by AML: if the AML configured by the SMF network element is null, and if the UPF network element 1 determines that the UE1 allows to join the first multicast group, the UPF network element 1 activates a routing rule corresponding to the first multicast group, and adds the multicast address of the first multicast group to the AML.

Then, the UPF network element 1 matches the multicast message with the multicast address included in the AML when receiving the multicast message, determines the multicast address matched with the multicast message, and further determines the routing rule matched with the multicast message. It can be understood that the UPF network element does not match the multicast packet with the destination address in the filter in the PDR, so that the matching efficiency can be improved.

Optionally, the UPF network element 1 forwards the first IGMP packet in step 305 to the N6 interface, so as to update a switch or a router in the data network. Specifically, the UPF network element 1 matches the first IGMP packet with the second type routing rule in the N4 session at the user level, determines a matched PDR1, and forwards the first IGMP packet to the internal interface of the UPF network element 1 according to the FAR corresponding to the PDR 1; the UPF network element 1 receives the first IGMP message from the internal interface thereof, matches the first IGMP message with the second type routing rule in the group-level N4 conversation, determines a matched PDR2, forwards the first IGMP message to the N6 interface according to the FAR corresponding to the PDR2, and forwards the first IGMP message to the data network, so that the data network can know the joining or exiting of the UE1, and further updates the switch or the router.

In step 308a, the UPF network element 1 sends an N4 report to the SMF network element. Accordingly, the SMF network element receives the N4 report from the UPF network element 1.

The UPF network element 1 may send an N4 report to the SMF network element informing the SMF network element that the UE1 joined or exited the designated multicast group.

Optionally, the SMF network element records or updates AML of each multicast group in case of receiving the N4 report, where the AML may further include group identification of the multicast group and activated UE id list. Optionally, the SMF network element updates the AML when the PDU session release triggers the UE1 to exit the first multicast group; otherwise, when the UE1 establishes the PDU session next time, the routing rule of the first multicast group needs to be restored according to AML.

If step 305 is not executed, the SMF network element may default to ACL, AML, that is, the routing rule corresponding to each multicast group is active. In other words, if the ACL obtained by the SMF is AML, the UE1 allows joining a certain multicast group in the ACL, and the UE1 can join the specified multicast group even without sending an IGMP packet for requesting to join the specified multicast group, thereby reducing the signaling overhead of the UE 1.

In step 309a, optionally, the SMF network element updates the routing rule corresponding to the first multicast group in the group-level N4 session corresponding to the 5G LAN group.

When the SMF network element first supports or last supports the multicast address carried by the first IGMP packet in step 305, the SMF network element may update the UL PDR of the first multicast group in the N4 session corresponding to the 5G LAN group of another UPF network element (e.g., UPF network element 2) according to the N4 report, where the UL PDR includes an internal interface parameter, network instance information, a multicast address, and packet replication information. The message duplication information may be N19 indication information or N6 indication information, the N19 indication information may be, for example, GTP-U TEID of an N19 tunnel with another UPF network element, and the N6 indication information may be, for example, information of an N6 interface. Correspondingly, the UL FAR corresponding to the UL PDR includes N19 tunnel information, such as GTP-U TEID of N19 tunnel, for forwarding the data packet matching the UL PDR of the first multicast group in the group level N4 session to the N19 tunnel connected by the UPF network element and other UPF network elements. In addition, the SMF network element may update the DL PDR of the first multicast group in the N4 session corresponding to the 5G LAN group of the UPF network element 1 according to the N4 report, where the DL PDR includes status indication information, network instance information, and a multicast address. Accordingly, the DL FAR corresponding to the DL PDR includes forwarding indication information (N19 indication information or N6 indication information). In addition, for the N4 session at the group level corresponding to the PDU session, the related descriptions of UL QER and UL URR corresponding to the UL PDR and DL QER and DL URR corresponding to the DL PDR may refer to the prior art, and are not described herein again.

In step 310a, optionally, the SMF network element sends the updated routing rule of the first multicast group in the group-level N4 session corresponding to the 5G LAN group to the UPF network element 1 and the UPF network element 2. Accordingly, UPF network element 1 and UPF network element 2 receive the routing rule for the first multicast group in the group-level N4 session corresponding to the updated 5G LAN group from the SMF network element. So that the UPF network element 1 and the UPF network element 2 update the routing rule of the first multicast group in the group-level N4 session corresponding to the 5G LAN group, and the UPF network element 2 controls the forwarding of the multicast packet of the first multicast group.

Optionally, the SMF network element notifies the AF network element to update the switch or router in the data network.

Step 308b, optionally, the UPF network element 1 sends an IGMP packet to the UPF network element 2. Correspondingly, the UPF network element 2 receives the IGMP message from the UPF network element 1. The IGMP message in step 308b is the IGMP message received by the UPF network element in step 305.

In step 309b, the UPF network element 2 determines whether the UE1 is allowed to join the first multicast group. Step 309b may refer to step 306.

In step 310b, if the determination result is yes, the UPF network element 2 sets the state of the routing rule corresponding to the first multicast group in the group-level N4 session corresponding to the 5G LAN group to the activated state.

If the UPF network element 2 is another UPF network element in the mesh structure, the UPF network element 2 sets the state of the UL PDR corresponding to the first multicast group in the group-level N4 session corresponding to the 5G LAN group to the activated state. If the UPF network element 2 is a middle UPF network element in the star structure, the UPF network element 2 sets the state of the DL PDR corresponding to the first multicast group in the group-level N session corresponding to the 5G LAN group to the activated state.

It should be noted that steps 308a to 310a are one implementation, and steps 308b to 310b are another implementation.

In the embodiment shown in fig. 7, the UPF network element may dynamically control the UE to join the first multicast group, and the UPF network element may set the state of the routing rule corresponding to the first multicast group to an active state according to the routing rule information set by the SMF network element, so that when the UPF network element receives the multicast packet, the forwarding of the multicast packet may be controlled according to the routing rule corresponding to the first multicast group, thereby efficiently and flexibly implementing forwarding control of the multicast packet.

As an alternative embodiment, after step 307, the method further includes:

if the UPF network element 1 receives the second IGMP packet from the UE1 for requesting to exit the first multicast group, it determines that the UE1 exits the first multicast group according to the first type of routing rule, and sets the routing rule corresponding to the first multicast group in the second type of routing rule to a deactivated state. Specifically, the UPF network element 1 matches the second IGMP packet with the first class of routing rules, and further determines, from the first class of routing rules, a second PDR matched with the second IGMP packet and a FAR associated with the second PDR, where a specified field in the FAR associated with the second PDR is a second value, and instructs the UE1 to exit the first multicast group and instructs the UPF network element 1 to set the state of the routing rule corresponding to the first multicast group in the second class of routing rules to the deactivated state.

Thereafter, the UPF network element 1 sends an N4 report to the SMF network element instructing the UE1 to exit the first multicast group. Thereafter, the SMF network element updates the routing rule of the first multicast group in the group-level N4 session corresponding to the 5G LAN group again according to the N4 report, e.g., sets the routing rule corresponding to the first multicast group to a deactivated state.

As an optional embodiment, in a case that the UPF network element 1 receives a third IGMP packet from the UE1 for requesting to join the second multicast group, the third IGMP packet is matched with the first routing rule, and then a third PDR matched with the third IGMP packet and a FAR associated with the third PDR are determined from the first routing rule, where a specified field in the FAR associated with the third PDR is a second value, and indicates that the UE1 is not allowed to join the second multicast group.

The embodiment shown in fig. 7 will be further described below by way of three examples, in connection with fig. 9 a-9 c. In fig. 9 a-9 c, it is assumed that UE1, UE2, and UE3 are all allowed to join multicast group a, multicast group b, and multicast group c. The light grey shading indicates routing rules for receive that are deactivated, the dark grey shading indicates routing rules for transmit, and the diagonal shading indicates routing rules that are activated.

Please refer to fig. 9a, which is a diagram illustrating a multicast communication method according to an embodiment of the present application. The SMF network element sets the state of the routing rule corresponding to the multicast group a-multicast group c as a deactivation state, and configures the routing rule corresponding to each multicast group on the UPF network element. When receiving the first IGMP packet from the UE1, the UPF network element is configured to request to join the multicast group a, determine whether the UE1 allows joining the multicast group a, and if the UE1 allows joining the multicast group a, the UPF network element sets the state of the routing rule corresponding to the multicast group a to an active state, for example, in fig. 9a, the PDRa and the FARa associated with the PDRa are set to an active state, which is indicated by oblique shading.

When receiving the multicast packet of the N19 tunnel or the N6 interface, the UPF network element skips the routing rule corresponding to the multicast group b, skips the routing rule corresponding to the multicast group c, searches for the routing rule matching the multicast packet in the routing rule corresponding to the multicast group a, matches the multicast packet in fig. 9a with the PDRa and the FARa for the PDU session 1, and forwards the multicast packet to the PDU session 1 of the UE1 through the internal interface. The transmission of the multicast message is indicated in fig. 9a by a bold solid line.

Under the condition that the UPF network element receives the multicast packet from the UE3, the multicast address carried in the multicast packet is the multicast address of the multicast group c, and the multicast address of the multicast packet is not matched with the routing rule corresponding to the activated multicast group a, so that the UPF network element does not forward the multicast packet to the corresponding PDU session. The transmission of the multicast message is indicated by the dashed line in fig. 9 a.

Please refer to fig. 9b, which is a diagram illustrating another multicast communication method according to an embodiment of the present application. In fig. 9b, a bitmap is used to indicate an activated state or a deactivated state, and the bitmap may be included in any PDR in the second type of routing rule, for example, the PDR corresponding to PDU session 2 in fig. 9b is set to include the bitmap. In fig. 9b, the bitmap includes 8 bits, each bit corresponds to the multicast address of one multicast group, and it is assumed that the first bit corresponds to the multicast address of multicast group a, the second bit corresponds to the multicast address of multicast group b, and so on. The UPF network element, upon receiving a first IGMP message from the UE1 requesting to join the multicast group a, determines whether the UE1 allows to join the multicast group a, and if the UE1 allows to join the multicast group a, activates a routing rule corresponding to the multicast group a, and changes a value of a first bit in the bitmap from "0" to "1".

In a possible implementation manner, when receiving a multicast packet of an N19 tunnel or an N6 interface, the UPF network element skips a bit of "0" in the bitmap, determines a multicast address corresponding to a bit of "1" in the bitmap according to a mapping relationship, and matches a routing rule corresponding to the multicast address corresponding to the bit of "1" with the multicast packet. In another possible implementation manner, when receiving a multicast packet of an N19 tunnel or an N6 interface, the UPF network element determines a multicast address corresponding to a bit in a bitmap according to the mapping relationship, skips over a routing rule corresponding to a multicast address corresponding to "0", and matches the routing rule corresponding to the multicast address corresponding to "1" with the multicast packet.

Please refer to fig. 9c, which is a diagram illustrating another multicast communication method according to an embodiment of the present application. In fig. 9c, the routing rule information sent by the SMF network element to the UPF network element carries creation indication information. Under the condition that the UPF network element receives the first IGMP message of the UE1 for requesting to join the multicast group a, the UPF network element determines whether the UE1 allows to join the multicast group a, and if the UE1 allows to join the multicast group a, the UPF network element autonomously creates a routing rule corresponding to the multicast group a. Then, if the UE1 requests to exit the multicast group a through the second IGMP packet, the UPF network element deletes the routing rule corresponding to the multicast group a. When receiving the multicast packet of the N19 tunnel or N6 interface, the UPF network element matches the routing rule corresponding to the created multicast group a with the multicast packet, and the multicast packet in fig. 9c matches the PDRa and the FARa for PDU session 1.

Currently, after receiving a data packet, the UPF network element detects the data packet and determines that the data packet matches the PDR (or, may be referred to as successfully matching the data packet to the PDR, or may be referred to as successfully matching the PDR to the data packet). The method specifically comprises the following four matching processes:

(1) and detecting the data packet according to the PDU session tunnel information of the data packet, the network instance information of the data packet, the interface information of the data packet and/or the packet head information of the data packet. If the PDU session tunnel information of the packet, the network instance information of the packet, the interface information of the packet, and/or the header information of the packet matches with the corresponding parameters in the UL PDR of the N4 session corresponding to the PDU session one by one, the UL PDR of the N4 session corresponding to the PDU session is successfully matched to the packet.

(2) And detecting the data packet according to the interface information of the data packet, the network instance information of the data packet and the packet header information of the data packet. If the interface information of the data packet, the network instance information of the data packet, the header information of the data packet, and the corresponding parameters in the DL PDR of the N4 session corresponding to the PDU session are matched one by one, the DL PDR of the N4 session corresponding to the PDU session is successfully matched to the data packet.

(3) And detecting the data packet according to the interface information of the data packet, the network instance information of the data packet and the packet header information of the data packet. If the interface information of the packet, the network instance information of the packet, and the header information of the packet match with the corresponding parameters in the UL PDR of the N4 session at the group level one by one, the UL PDR of the N4 session at the group level is successfully matched to the packet.

(4) The packet is detected based on the interface information of the packet, the network instance information of the packet, and/or the N19 tunnel information of the packet. If the interface information of the packet, the network instance information of the packet, and/or the tunnel information of the packet match the corresponding parameters in the DL PDR of the group level N4 session one by one, the DL PDR of the group level N4 session is successfully matched to the packet.

In a specific implementation, the UPF network element performs one or more of the above four matching procedures to match the data packet to the PDR.

In the embodiment of the present application, in addition to the above parameter matching, if the data packet includes a multicast address, the PDR is considered to be successfully matched to the data packet only when the interface information of the data packet, the network instance information of the data packet, the multicast address in the header information of the data packet, and/or the N19/PDU session tunnel information of the data packet is equal to the corresponding parameters in the PDR (including the UL PDR and the DL PDR).

Referring to fig. 10, a schematic flowchart of another multicast communication method provided in this embodiment of the present application is shown, where the method includes the following steps:

in step 401, optionally, UE1 sends a PDU session setup request to the SMF network element. Accordingly, the SMF network element receives a PDU session setup request from the UE 1.

The difference with step 301 is that the PDU session setup request in step 401 is used to request to join or leave the first multicast group, including the group identity or multicast address of the first multicast group, in addition to requesting to establish a PDU session. The PDU session setup request in step 401 may be a Non-access stratum (NAS) request.

Alternatively, the PDU session setup request in step 401 includes the operation type [ join/exit/update ], and the multicast address or group identification.

The UE1 may carry the PDU session establishment request in an NAS Session Management (SM) message; the PDU session establishment request may also be carried in NAS transport (transport) and sent to the AMF network element through the access network device, and the AMF network element sends the PDU session establishment request to the SMF network element through an N11 message.

In step 402, the SMF network element obtains multicast access control information of the UE 1. Step 402 may be described in detail with reference to step 302 in the embodiment shown in FIG. 7.

In step 403, the SMF network element sends forwarding indication information to the UPF network element 1. Accordingly, the UPF network element 1 receives the forwarding indication information from the SMF network element.

In the process of establishing the PDU session of the UE1, the SMF network element sends forwarding indication information to the UPF network element 1, where the forwarding indication information is used to indicate the UPF network element 1 to forward the first IGMP packet received by the UPF network element from the UE1 to the SMF network element. It is also used to indicate that, if the UPF network element 1 forwards a subsequent received IGMP packet to the SMF network element, for example, a second IGMP packet.

In step 404, the UE1 sends a first IGMP packet to the UPF network element 1. Accordingly, UPF network element 1 receives the first IGMP message from UE 1.

Step 405, the UPF network element 1 sends the first IGMP packet to the SMF network element. Correspondingly, the SMF network element receives the first IGMP packet from the UPF network element 1.

In step 406, optionally, the UE1 sends a PDU session modification request to the SMF network element. Accordingly, the SMF network element receives a PDU session modification request from the UE 1.

The PDU session modification request may be a NAS request, and is used for requesting to join or leave the first multicast group, including the group identifier or the multicast address of the first multicast group, in addition to requesting to modify the PDU session.

It should be noted that step 401, step 404, and step 406 are in parallel, and one of the steps may be executed.

In step 407, the SMF network element determines whether the UE1 is allowed to join the first multicast group.

The implementation procedure of step 407 may refer to step 306, where the UPF network element 1 determines whether the UE1 is allowed to join the first multicast group.

Optionally, after the judgment, the SMF network element records AML of each multicast group, where the AML includes a group identifier, a multicast address, and an activated UE ID list of the multicast group. Optionally, the SMF network element updates the AML when the PDU session release triggers the UE1 to exit the first multicast group; otherwise, when the UE1 establishes the PDU session next time, the routing rule of the first multicast group needs to be restored according to AML.

If steps 401, 404 and 406 are all executed, the SMF network element may default to AML, that is, the routing rule corresponding to each multicast group is in an active state. In other words, in the case where the ACL acquired by the SMF is AML, the UE1 allows joining a certain multicast group in the ACL, and signaling overhead of the UE1 can be reduced.

The SMF network element updates the routing rules in the N4 session at the user level, step 408.

Specifically, the SMF network element creates or deletes a DL PDR corresponding to the PDU session of the UE and a DL FAR associated with the DL PDR. Wherein the DL PDR comprises tunnel parameter information, network instance information and multicast address, and the DL FAR associated with the DL PDR comprises internal interface parameters and N19 indication information or N6 indication information.

In step 409, the SMF network element sends the updated routing rule in the N4 session at the user level to the UPF network element 1. Accordingly, the UPF network element 1 receives the updated routing rules in the N4 session at the subscriber level from the SMF network element.

Optionally, step 409 further includes:

and the SMF network element updates the routing rule in the N4 session at the group level, specifically updates the DL PDR in the N4 session at the group level and the DL FAR associated with the DL PDR, when the UPF network element 1 supports the corresponding multicast communication for the first time. Wherein the DL PDR comprises tunnel parameter information, network instance information and multicast address, and the DL FAR associated with the DL PDR comprises internal interface parameters and N19 indication information or N6 indication information. The SMF network element may send the updated routing rules in the group level N4 session to UPF network element 1.

And under the condition that the UPF network element 1 supports the corresponding multicast communication for the first time, the SMF network element updates the routing rule in the group-level N4 session of other UPF network elements for the network with a full connection structure, and specifically updates the UL PDR in the group-level N4 session and the UL FAR related to the UL PDR. The UL PDR includes internal interface parameters, network instance information, multicast address and message copy information (indicating information N19/N6), and the UL FAR associated with the UL PDR includes N19 tunnel information.

Optionally, when the UPF network element 1 supports the corresponding multicast communication for the first time, the SMF network element updates, for the star network, the routing rule in the group-level N4 session of the other UPF network element, and specifically updates the DL PDR in the group-level N4 session and the DL FAR associated with the DL PDR. The DL PDR includes network instance information, multicast address, and message copy information (N19 tunnel information/address of UE 1), and the DL FAR associated with the DL PDR includes N19 tunnel information.

In the embodiment shown in fig. 10, the SMF network element determines whether the UE1 is allowed to join or leave the first multicast group, and creates or deletes the routing rule corresponding to the first multicast group in the UPF network element 1, whereas in the embodiment shown in fig. 7, the UPF network element 1 determines whether the UE1 is allowed to join or leave the first multicast group and sets the state of the routing rule corresponding to the first multicast group to an activated state or a deactivated state.

Illustratively, a first IGMP message sent by the UE1 is used to request to join the multicast group a, and if the SMF network element determines that the UE1 allows to join the multicast group a when receiving the first IGMP message, the SMF network element creates a routing rule for the PDU session of the UE1 and configures the routing rule in the N4 session of the UPF network element 1. Then, the UPF network element 1 may match the multicast packet with the existing routing rule when receiving the multicast packet for the multicast address of the multicast group a, and further forward the multicast packet to the corresponding PDU session.

Please refer to fig. 11, which is a schematic structural diagram of a communication device according to an embodiment of the present disclosure. The communication device 700 shown in fig. 11 may include a transceiving unit 701 and a processing unit 702. The transceiver unit 701 may include a transmitting unit and a receiving unit, the transmitting unit is configured to implement a transmitting function, the receiving unit is configured to implement a receiving function, and the transceiver unit 701 may implement a transmitting function and/or a receiving function. The transceiving unit may also be described as a communication unit.

In a possible implementation manner, the communication apparatus 700 may be a user plane network element, or an apparatus in the user plane network element, or an apparatus that can be used in cooperation with a session management network element.

In the process of establishing a PDU session of a terminal device, the transceiver 701 is configured to receive routing rule information from a session management network element; the routing rule information corresponds to multicast access control information of the terminal equipment, the multicast access control information comprises indication information of whether the terminal equipment allows to join one or more multicast groups, and the routing rule information comprises a first class routing rule and a second class routing rule; the first type of routing rule comprises a routing rule for processing an IGMP message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which is allowed to be added by terminal equipment, and the state of the routing rule in the second type of routing rule is a deactivation state;

the transceiving unit 701 is further configured to receive a first IGMP packet from the terminal device, where the first IGMP packet is used to request to join a first multicast group;

a processing unit 702, configured to, when the processing unit 702 determines that the first multicast group is any one multicast group that the terminal device is allowed to join in one or more multicast groups, set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an active state.

Optionally, the processing unit 702 is further configured to determine, according to the first type of routing rule, that the first multicast group is a multicast group that the terminal device is allowed to join in one or more multicast groups.

Optionally, the processing unit 702 is specifically configured to determine that the first IGMP packet matches a first PDR in the first class of routing rules, and an FAR associated with the first PDR indicates that the terminal device is allowed to join the first multicast group.

Optionally, the FAR associated with the first PDR is further configured to instruct the user plane network element to set, as an active state, a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule.

Optionally, a value of a specified field in the FAR associated with the first PDR is a first value, where the first value indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an active state.

Optionally, the transceiving unit 701 is further configured to receive a second IGMP packet from the terminal device, where the second IGMP packet is used to request to exit the first multicast group;

the processing unit 702 is further configured to determine, according to the first type of routing rule, that the terminal device exits the first multicast group; and setting the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as a deactivation state.

Optionally, the processing unit 702 is specifically configured to determine that the second IGMP packet matches a second PDR in the first-class routing rule, and an FAR associated with the second PDR indicates that the terminal device exits the first multicast group.

Optionally, the FAR associated with the second PDR is further configured to instruct the user plane network element to set a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to a deactivated state.

Optionally, a value of a specified field in the FAR associated with the second PDR is a second value, where the second value indicates that the terminal device exits the first multicast group and indicates the user plane network element to set a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to a deactivated state.

Optionally, the transceiving unit 701 is further configured to receive a third IGMP packet from the terminal device, where the third IGMP packet is used to request to join the second multicast group;

the processing unit 702 is further configured to determine, according to the first type of routing rule, that the terminal device is not allowed to join the second multicast group.

Optionally, the processing unit 702 is specifically configured to determine that the third IGMP packet matches a third PDR in the first-class routing rule, and an FAR associated with the third PDR indicates that the terminal device is not allowed to join the second multicast group.

Optionally, a value of a specified field in the FAR associated with the third PDR is a third value, where the third value indicates that the terminal device is not allowed to join the second multicast group.

Optionally, the transceiver 701 is further configured to receive a multicast packet;

the processing unit 702 is further configured to skip the routing rule in the deactivated state and match the routing rule in the activated state with the multicast packet in the process of searching for the routing rule matching the multicast packet in the second type of routing rule.

Optionally, the routing rule in the second type of routing rule includes state indication information, where the state indication information is used to indicate that the state of the corresponding routing rule in the second type of routing rule is an activated state or a deactivated state.

Optionally, the routing rule information further includes a bitmap associated with the second type of routing rule, where the bitmap includes N bits, and N is a natural number; any bit in the bitmap has a mapping relation with the multicast address of the multicast group allowed to be added by the terminal equipment;

setting the value of any bit in the bitmap as a first preset value or a second preset value; the first preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state;

the processing unit 702 is configured to set a state of a routing rule corresponding to a multicast address of the first multicast group in the second type of routing rule as an active state, specifically, determine a bit corresponding to the first multicast group from a bitmap included in the second type of routing rule according to the mapping relationship, and set a value of the bit corresponding to the multicast address of the first multicast group as a second preset value.

The processing unit 702 is configured to set a routing rule corresponding to a multicast address of the first multicast group in the second type of routing rule to a deactivated state, specifically, to determine a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule according to the mapping relationship, and set a value of the bit corresponding to the multicast address of the first multicast group to a first preset value.

Optionally, the transceiver 701 is further configured to receive the mapping relationship from the session management network element.

the processing unit 702 is further configured to skip bits in the bitmap that are the first preset value, determine, according to the mapping relationship, a multicast address corresponding to bits in the bitmap that are the second preset value, and match a routing rule corresponding to the multicast address corresponding to the bits of the second preset value with the multicast packet.

Optionally, the multicast access control information is a multicast access control list ACL.

Optionally, the routing rule information further includes an AML associated with the second type of routing rule, where the AML is null or includes one or more multicast addresses, and the one or more multicast addresses included in the AML are multicast addresses of multicast groups allowed to join by the terminal device; when the AML is empty, the states of all the routing rules included in the second type of routing rules are in a deactivation state; when AML includes multicast address X, it indicates that the state of the route rule corresponding to multicast address X is active state.

In a possible implementation manner, the communication device 700 may be a session management network element, a device in the session management network element, or a device that can be used in cooperation with the session management network element.

In the process of establishing a PDU session of a terminal device, a transceiver 701 is configured to acquire multicast access control information of the terminal device, where the multicast access control information includes indication information of whether the terminal device allows to join one or more multicast groups;

a processing unit 702, configured to set routing rule information according to the multicast access control information; the routing rule information comprises a first type of routing rule and a second type of routing rule; the first type of routing rule is a routing rule for processing an IGMP message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which is allowed to be added by terminal equipment, and the state of the routing rule in the second type of routing rule is a deactivation state;

the transceiving unit 701 is further configured to send routing rule information to the user plane network element.

Optionally, the processing unit 702 is specifically configured to set a second type routing rule and a first type routing rule according to the multicast access control information, and set a state of a routing rule included in the second type routing rule as a deactivated state.

Optionally, the processing unit 702 is specifically configured to set, as a first value, a value of a specified field in a first PDR matched with the first IGMP packet and a FAR associated with the first PDR, for a first IGMP packet used by the terminal device to request to join the first multicast group; setting the value of a designated field in the FAR associated with the first PDR as a first value; the first value indicates that the terminal equipment is allowed to join the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state;

wherein, the first multicast group is a multicast group which is allowed to join by the terminal device in one or more multicast groups.

Optionally, the processing unit 702 is specifically configured to set, as a second value, a value of a specified field in a second PDR matched with the second IGMP packet and a FAR associated with the second PDR, for a second IGMP packet used by the terminal device to request to exit the first multicast group; setting the value of a designated field in the FAR associated with the second PDR as a second value; the second value indicates the terminal equipment to exit the first multicast group and indicates the user plane network element to set the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as a deactivation state;

Optionally, the processing unit 702 is specifically configured to set, as a third value, a value of a specified field in a third PDR matched with the third IGMP packet and a FAR associated with the third PDR, for a third IGMP packet used by the terminal device to request to join the second multicast group; setting the value of a designated field in the FAR associated with the third PDR as a first value; the first value indicates that the terminal device is not allowed to join the second multicast group; the second multicast group is a multicast group in which the end devices in one or more multicast groups are not allowed to join.

a processing unit 702, configured to specifically set, according to the multicast access control information, a value of a bit corresponding to a multicast address of a multicast group that the terminal device is allowed to join in the bitmap as a first preset value; and/or setting the value of the bit corresponding to the multicast address of the multicast group which is not allowed to be added by the terminal equipment in the bitmap as a second preset value.

Optionally, the transceiver 701 is further configured to send the mapping relationship to a user plane network element.

Optionally, the routing rule information further includes AML associated with the second type of routing rule, and the AML is set to null; wherein the AML is used for indicating the routing rule in the activated state in the second type of routing rule.

Optionally, the transceiver 701 is further configured to receive an N4 report from the user plane network element, where the N4 report is used to instruct the terminal device to join or leave the first multicast group; the terminal device belongs to the 5G LAN group;

the processing unit 702 is further configured to update, according to the N4 report, a routing rule corresponding to the multicast address of the first multicast group in the N4 session at the group level corresponding to the 5G LAN group of the user plane network element and/or other user plane network elements.

Fig. 12 is a schematic diagram showing the structure of another communication apparatus. The communication device 800 may be a user plane network element, a session management network element, a chip system, or a processor supporting the user plane network element to implement the method described above, or a chip, a chip system, or a processor supporting the session management network element to implement the method described above. The apparatus may be configured to implement the method described in the method embodiment, and refer to the description in the method embodiment.

The communication device 800 may include one or more processors 801. The processor 801 may be a general purpose processor, a special purpose processor, or the like. For example, a baseband processor or a central processor. The baseband processor may be configured to process communication protocols and communication data, and the central processor may be configured to control the communication device, execute software programs, and process data of the software programs.

Optionally, the communication device 800 may include one or more memories 802, on which instructions 804 may be stored, and the instructions may be executed on the processor 801, so that the device 800 performs the methods described in the above method embodiments. Optionally, the memory 802 may further store data. The processor 801 and the memory 802 may be provided separately or may be integrated together.

Optionally, the communication device 800 may further include a transceiver 805 and an antenna 806. The transceiver 805 may be referred to as a transceiving unit, a transceiver, or a transceiving circuit, etc. for implementing transceiving functions. The transceiver 805 may include a receiver and a transmitter, and the receiver may be referred to as a receiver or a receiving circuit, etc. for implementing a receiving function; the transmitter may be referred to as a transmitter or a transmission circuit, etc. for implementing the transmission function.

The communication device 800 is a user plane network element: the processor 801 is configured to execute step 306 and step 307 in fig. 7. The transceiver 805 is configured to perform step 304, step 305, step 308a, step 310a, and step 308b in fig. 7; step 403, step 404, step 405 and step 409 in fig. 10 are performed.

The communication device 800 is a session management network element: the processor 801 is configured to perform step 302, step 303, and step 309a in fig. 7; step 402, step 407 and step 408 in fig. 10 are performed. The transceiver 805 is configured to perform step 301, step 304, step 308a, and step 310a in fig. 7; step 401, step 403, step 405, step 406 and step 409 in fig. 10 are performed.

In an alternative design, the processor 801 may include a transceiver to perform receive and transmit functions. The transceiver may be, for example, a transceiver circuit, or an interface circuit. The transmit and receive circuitry, interfaces or interface circuitry used to implement the receive and transmit functions may be separate or integrated. The transceiver circuit, the interface circuit or the interface circuit may be used for reading and writing code/data, or the transceiver circuit, the interface circuit or the interface circuit may be used for transmitting or transferring signals.

In yet another possible design, the processor 801 may optionally have instructions 803 stored therein, and the instructions 803 run on the processor 801, so that the apparatus 800 may perform the method described in the above method embodiment. The instructions 803 may be solidified in the processor 801, in which case the processor 801 may be implemented in hardware.

In yet another possible design, communications device 800 may include circuitry that may implement the functionality of transmitting or receiving or communicating in the foregoing method embodiments. The processors and transceivers described herein may be implemented on Integrated Circuits (ICs), analog ICs, Radio Frequency Integrated Circuits (RFICs), mixed signal ICs, Application Specific Integrated Circuits (ASICs), Printed Circuit Boards (PCBs), electronic devices, and the like. The processor and transceiver may also be fabricated using various IC process technologies, such as Complementary Metal Oxide Semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), P-type metal oxide semiconductor (PMOS), Bipolar Junction Transistor (BJT), Bipolar CMOS (bicmos), silicon germanium (SiGe), gallium arsenide (GaAs), and the like.

The communication apparatus in the above description of the embodiment may be a network device or a terminal device, but the scope of the communication apparatus described in the present application is not limited thereto, and the structure of the communication apparatus may not be limited by fig. 12. The communication means may be a stand-alone device or may be part of a larger device.

Those skilled in the art will also appreciate that the various illustrative logical blocks and steps (step) set forth in the embodiments of the present application may be implemented in electronic hardware, computer software, or combinations of both. Whether such functionality is implemented as hardware or software depends upon the particular application and design requirements of the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the embodiments of the present application.

The present application also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a computer, implements the functionality of any of the above-described method embodiments.

The present application also provides a computer program product which, when executed by a computer, implements the functionality of any of the above-described method embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

Those of ordinary skill in the art will understand that: the various numbers of the first, second, etc. mentioned in this application are only used for the convenience of description and are not used to limit the scope of the embodiments of this application, but also to indicate the sequence.

The correspondence shown in the tables in the present application may be configured or predefined. The values of the information in each table are only examples, and may be configured to other values, which is not limited in the present application. When the correspondence between the information and each parameter is configured, it is not always necessary to configure all the correspondences indicated in each table. For example, in the table in the present application, the correspondence shown in some rows may not be configured. For another example, appropriate modification adjustments, such as splitting, merging, etc., can be made based on the above tables. The names of the parameters in the tables may be other names understandable by the communication device, and the values or the expression of the parameters may be other values or expressions understandable by the communication device. When the above tables are implemented, other data structures may be used, for example, arrays, queues, containers, stacks, linear tables, pointers, linked lists, trees, graphs, structures, classes, heaps, hash tables, or hash tables may be used.

Predefinition in this application may be understood as defining, predefining, storing, pre-negotiating, pre-configuring, curing, or pre-firing.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of multicast communication, comprising:

in the process of establishing a Protocol Data Unit (PDU) session of terminal equipment, a user plane network element receives routing rule information from a session management network element; the routing rule information corresponds to multicast access control information of the terminal device, the multicast access control information includes indication information of whether the terminal device allows to join one or more multicast groups, and the routing rule information includes a first type routing rule and a second type routing rule; the first type of routing rule comprises a routing rule for processing an Internet Group Management Protocol (IGMP) message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which the terminal equipment allows to join, and the state of the routing rule in the second type of routing rule is a deactivation state;

the user plane network element receives a first IGMP message from the terminal equipment, wherein the first IGMP message is used for requesting to join a first multicast group;

and when the first multicast group is any one multicast group allowed to join by the terminal equipment in the one or more multicast groups, the user plane network element sets the state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an activated state.

2. The method of claim 1, further comprising:

and the user plane network element determines that the first multicast group is a multicast group allowed to be added by the terminal equipment in the one or more multicast groups according to the first type of routing rule.

3. The method according to claim 2, wherein the determining, by the user plane network element according to the first type of routing rule, that the first multicast group is a multicast group that the terminal device is allowed to join in the one or more multicast groups specifically includes:

and the user plane network element determines that the first IGMP message matches a first message detection rule PDR in the first routing rule, and a forwarding action rule FAR associated with the first PDR indicates that the terminal equipment is allowed to join the first multicast group.

4. The method of claim 3, wherein the FAR associated with the first PDR further instructs the user plane network element to set a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an active state.

5. The method according to claim 4, wherein a value of a specified field in the FAR associated with the first PDR is a first value, and the first value indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element to set a state of a routing rule corresponding to a multicast address of the first multicast group in the second type of routing rule to an active state.

6. The method according to any one of claims 1-5, further comprising:

the user plane network element receives a second IGMP message from the terminal equipment, wherein the second IGMP message is used for requesting to quit the first multicast group;

the user plane network element determines that the terminal equipment exits the first multicast group according to the first type of routing rule;

and the user plane network element sets the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to be in a deactivation state.

7. The method according to claim 6, wherein the determining, by the user plane network element according to the first type of routing rule, that the terminal device exits the first multicast group specifically is:

and the user plane network element determines that the second IGMP message matches a second PDR in the first routing rule, and an FAR associated with the second PDR indicates that the terminal equipment exits the first multicast group.

8. The method of claim 7, wherein the FAR associated with the second PDR further instructs the user plane network element to set a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to a deactivated state.

9. The method according to claim 8, wherein a value of a specified field in an FAR associated with the second PDR is a second value, and the second value indicates that the terminal device exits the first multicast group and indicates that the user plane network element sets a state of a routing rule corresponding to a multicast address of the first multicast group in the second type of routing rule to a deactivated state.

10. The method according to any one of claims 1-9, further comprising:

the user plane network element receives a third IGMP message from the terminal equipment, wherein the third IGMP message is used for requesting to join a second multicast group;

and the user plane network element determines that the terminal equipment is not allowed to join the second multicast group according to the first type of routing rule.

11. The method according to claim 10, wherein the determining, by the user plane network element, that the terminal device is not allowed to join the second multicast group according to the first type of routing rule specifically includes:

and the user plane network element determines that the third IGMP packet matches a third PDR in the first class of routing rules, and an FAR associated with the third PDR indicates that the terminal device is not allowed to join the second multicast group.

12. The method according to claim 11, wherein a value of a specified field in an FAR associated with the third PDR is a third value, and the third value indicates that the terminal device is not allowed to join the second multicast group.

13. The method according to any one of claims 1-12, further comprising:

the user plane network element receives a multicast message;

and in the process of searching the routing rule matched with the multicast message in the second type of routing rule, the user plane network element skips the routing rule in the deactivated state and matches the routing rule in the activated state with the multicast message.

14. The method according to any of claims 1 to 13, wherein the routing rule in the second type of routing rule includes status indication information, and the status indication information is used to indicate that the status of the corresponding routing rule in the second type of routing rule is an activated status or a deactivated status.

15. The method according to any of claims 1-13, wherein the routing rule information further comprises a bitmap associated with the second type of routing rule, the bitmap comprising N bits, N being a natural number; any bit in the bitmap has a mapping relation with a multicast address of a multicast group allowed to be added by the terminal equipment;

setting the value of any bit in the bitmap to be a first preset value or a second preset value; the first preset value is used for indicating that a routing rule corresponding to a multicast address corresponding to a bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state.

16. The method according to claim 15, wherein the user plane network element sets a state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an active state, specifically:

and the user plane network element determines the bit corresponding to the multicast address of the first multicast group from the bitmap included in the second type of routing rule according to the mapping relation, and sets the value of the bit corresponding to the multicast address of the first multicast group as the second preset value.

17. The method according to claim 15, wherein the user plane network element sets a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to a deactivated state, specifically:

and the user plane network element determines the bit corresponding to the multicast address of the first multicast group from the bitmap included in the second type of routing rule according to the mapping relation, and sets the value of the bit corresponding to the multicast address of the first multicast group as the first preset value.

18. The method according to any one of claims 15-17, further comprising:

and the user plane network element receives the mapping relation from the session management network element.

19. The method according to any of claims 1-13, wherein said routing rule information further comprises an active member list AML associated with said second type of routing rule, said AML being empty or comprising one or more multicast addresses; one or more multicast addresses included in the AML are multicast addresses of multicast groups allowed to be added by the terminal equipment;

when the AML is empty, indicating that the states of all routing rules included in the second type of routing rule are in a deactivation state; and when the AML comprises a multicast address X, indicating that the state of the routing rule corresponding to the multicast address X is an activated state.

20. The method according to any of claims 1-19, wherein said multicast access control information is a multicast access control list, ACL.

21. A method of multicast communication, comprising:

in the process of establishing a Protocol Data Unit (PDU) session of a terminal device, a session management network element acquires multicast access control information of the terminal device, wherein the multicast access control information comprises indication information of whether the terminal device is allowed to join one or more multicast groups;

the session management network element sets routing rule information according to the multicast access control information; the routing rule information comprises a first type of routing rule and a second type of routing rule; the first type of routing rule is a routing rule for processing an Internet Group Management Protocol (IGMP) message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which the terminal equipment allows to join, and the state of the routing rule in the second type of routing rule is a deactivation state;

and the session management network element sends the routing rule information to a user plane network element.

22. The method of claim 21, wherein the setting, by the session management network element, routing rule information according to the multicast access control information comprises:

and the session management network element sets the second type routing rule and the first type routing rule according to the multicast access control information, and sets the state of the routing rule included in the second type routing rule as a deactivation state.

23. The method of claim 22, wherein the setting, by the session management network element, the first type of routing rule according to the multicast access control information comprises:

the session management network element sets a first PDR matched with a first IGMP message and an FAR associated with the first PDR aiming at the first IGMP message used by the terminal equipment for requesting to join a first multicast group; setting the value of a designated field in the FAR associated with the first PDR as a first value; the first value indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element to set the state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an activated state;

wherein the first multicast group is a multicast group that the terminal device is allowed to join in the one or more multicast groups.

24. The method of claim 22, wherein the setting, by the session management network element, the first type of routing rule according to the multicast access control information comprises:

the session management network element sets a second PDR matched with the second IGMP message and an FAR associated with the second PDR for a second IGMP message used by the terminal equipment for requesting to quit the first multicast group; setting the value of a designated field in the FAR associated with the second PDR as a second value; the second value indicates that the terminal device exits the first multicast group and indicates that the user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to be a deactivated state;

25. The method of claim 22, wherein the setting, by the session management network element, the first type of routing rule according to the multicast access control information comprises:

the session management network element sets a third PDR matched with a third IGMP message and an FAR associated with the third PDR for the third IGMP message used by the terminal equipment for requesting to join a second multicast group; setting the value of a designated field in the FAR associated with the three PDRs as a third value; the third value indicates that the terminal device is not allowed to join the second multicast group;

wherein the second multicast group is a multicast group that the end device is not allowed to join in the one or more multicast groups.

26. The method according to any of claims 22-25, wherein a routing rule in the second class of routing rules comprises status indication information, and the status indication information is used to indicate that the status of the corresponding routing rule in the second class of routing rules is an activated status or a deactivated status.

27. The method according to any of claims 22-25, wherein said routing rule information further comprises a bitmap associated with said second type of routing rule, said bitmap comprising N bits, N being a natural number; any bit in the bitmap has a mapping relation with a multicast address of a multicast group allowed to be added by the terminal equipment;

setting the value of any bit in the bitmap to be a first preset value or a second preset value; the first preset value is used for indicating that a routing rule corresponding to a multicast address corresponding to a bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state;

the session management network element sets the second type of routing rule according to the multicast access control information, and the method comprises the following steps:

and the session management network element sets the value of the bit corresponding to the multicast address of the multicast group which the terminal equipment allows to join in the bitmap as the first preset value according to the multicast access control information.

28. The method of claim 27, further comprising:

and the session management network element sends the mapping relation to the user plane network element.

29. The method according to any of claims 22-25, wherein said routing rule information further comprises an active member list AML associated with said second type of routing rule, and wherein said AML is set to null; wherein the AML is used for indicating the routing rule in the second type of routing rule in an activated state.

30. The method according to any one of claims 21-29, further comprising:

the session management network element receiving an N4 report from the user plane network element, the N4 report being used to instruct the terminal device to join or leave the first multicast group; the terminal equipment belongs to a 5G LAN group; and the session management network element updates a routing rule corresponding to the multicast address of the first multicast group in the N4 session at the group level corresponding to the 5G LAN group for the user plane network element and/or other user plane network elements according to the N4 report.

31. A communication device, characterized in that the communication device comprises means for performing the steps of any of claims 1-20.

32. A communication device, characterized in that the communication device comprises means for performing the steps of any of claims 21-30.

33. A communication device, comprising a processor and a memory;

the memory is to store computer instructions;

the instructions, when executed by the processor, cause the communication device to perform the method of any of claims 1-20.

34. A communication device, comprising a processor and a memory;

the memory is to store computer instructions;

the instructions, when executed by the processor, cause the communication device to perform the method of any of claims 21-30.

35. A multicast communication system comprising a session management network element and a user plane network element;

the session management network element is configured to acquire multicast access control information of a terminal device during a PDU session establishment process of the terminal device, where the multicast access control information includes indication information of whether the terminal device allows to join one or more multicast groups; setting routing rule information according to the multicast access control information; the routing rule information comprises a first type of routing rule and a second type of routing rule; the first type of routing rule comprises a routing rule for processing an IGMP message, the second type of routing rule comprises a routing rule corresponding to a multicast address of a multicast group which the terminal equipment allows to join, and the state of the routing rule in the second type of routing rule is a deactivation state; sending the routing rule information to a user plane network element;

the user plane network element is used for receiving the routing rule information; receiving a first IGMP message from the terminal equipment, wherein the first IGMP message is used for requesting to join a first multicast group; and when the first multicast group is any one multicast group which the terminal equipment allows to join in the one or more multicast groups, setting the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule as an activated state.

36. The system of claim 35, wherein the session management network element is specifically configured to set the second type of routing rule and the first type of routing rule according to the multicast access control information, and set a state of a routing rule included in the second type of routing rule to a deactivated state.

37. The system of claim 36,

the session management network element is specifically configured to set, for the first IGMP packet, a first PDR matched with the first IGMP packet and a FAR associated with the first PDR; setting the value of a specified field in the FAR associated with the first PDR as a first value; the first value indicates that the terminal device is allowed to join the first multicast group and indicates the user plane network element to set the state of a routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to an activated state;

the user plane network element is specifically configured to match the first IGMP packet with the first class routing rule; under the condition that the first PDR is matched, acquiring FAR associated with the first PDR; and the value of a specified field in the FAR associated with the first PDR is the first value, the terminal equipment is determined to be allowed to join the first multicast group, and the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to be an activated state.

38. The system of claim 36,

the session management network element is specifically configured to set, for a second IGMP packet used by the terminal device to request to exit the first multicast group, a second PDR matched with the second IGMP packet and a FAR associated with the second PDR; setting the value of a specified field in the FAR associated with the second PDR as a second value; the second value indicates that the terminal device exits the first multicast group and indicates that the user plane network element sets the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule to be a deactivated state;

the user plane network element is further configured to receive the second IGMP packet, and match the second IGMP packet with the first type of routing rule; under the condition that the second PDR is matched, acquiring FAR associated with the second PDR; and the value of the specified field in the FAR associated with the second PDR is the second value, the terminal equipment is determined to exit the first multicast group, and the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set to be a deactivation state.

39. The system of claim 36,

the session management network element is specifically configured to set, for a third IGMP packet used by the terminal device to request to join the second multicast group, a third PDR matched with the third IGMP packet and a FAR associated with the third PDR; setting the value of a specified field in the FAR associated with the third PDR as a third value; the third value indicates that the terminal device is not allowed to join the second multicast group; the second multicast group is a multicast group that the terminal device is not allowed to join in the one or more multicast groups;

the user plane network element is further configured to receive the third IGMP packet, and match the third IGMP packet with the first type routing rule; under the condition that the third PDR is matched, acquiring FAR associated with the third PDR; and the value of the specified field in the FAR associated with the second PDR is the third value, and the terminal equipment is determined not to be allowed to join the second multicast group.

40. The system of any one of claims 35-39,

the user plane network element is also used for receiving multicast messages; and in the process of searching the routing rule matched with the multicast message in the second type of routing rule, skipping the routing rule in the deactivated state, and matching the routing rule in the activated state with the multicast message.

41. The system according to any of claims 35-39, wherein a routing rule in said second class of routing rules comprises status indication information, said status indication information being used to indicate whether a corresponding routing rule in said second class of routing rules is in an activated state or a deactivated state.

42. The system according to any of claims 35-39, wherein said routing rule information further comprises a bitmap associated with said second type of routing rule, said bitmap comprising N bits, N being a natural number; any bit in the bitmap has a mapping relation with a multicast address of a multicast group allowed to be added by the terminal equipment;

setting the value of any bit in the bitmap as a first preset value or a second preset value; the first preset value is used for indicating that a routing rule corresponding to a multicast address corresponding to a bit is in a deactivation state; the second preset value is used for indicating that the routing rule corresponding to the multicast address corresponding to the bit is in an activated state;

the session management network element is specifically configured to set, according to the multicast access control information, a value of a bit corresponding to a multicast address of a multicast group that the terminal device is allowed to join in the bitmap as the first preset value;

the user plane network element is specifically configured to, when the first multicast group is any one of the one or more multicast groups that the terminal device is allowed to join, determine, according to the mapping relationship, a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule, and set a value of the bit corresponding to the multicast address of the first multicast group to the second preset value.

43. The system of claim 42,

the user plane network element is configured to, when the state of the routing rule corresponding to the multicast address of the first multicast group in the second type of routing rule is set as a deactivated state, specifically, determine, according to the mapping relationship, a bit corresponding to the multicast address of the first multicast group from a bitmap included in the second type of routing rule, and set a value of the bit corresponding to the multicast address of the first multicast group as the first preset value.

44. The system of claim 42 or 43,

and the session management network element is further configured to send the mapping relationship to the user plane network element.

45. The system according to any of claims 35-39, wherein said routing rule information further comprises an active member list AML associated with said second type of routing rule, said AML being empty or comprising one or more multicast addresses; one or more multicast addresses included in the AML are multicast addresses of multicast groups allowed to be added by the terminal equipment;

46. The system of any one of claims 35-45,

the user plane network element is further configured to send an N4 report to the session management network element, where the N4 report is used to instruct the terminal device to join or leave the first multicast group; the terminal equipment belongs to a 5G LAN group;

the session management network element is further configured to update, according to the N4 report, a routing rule corresponding to a multicast address of the first multicast group in the N4 session at a group level corresponding to the 5G LAN group for the user plane network element and/or other user plane network elements.