WO2017113240A1

WO2017113240A1 - Method, apparatus and system for processing keepalive probe packet

Info

Publication number: WO2017113240A1
Application number: PCT/CN2015/099974
Authority: WO
Inventors: 胡星星; 张宏卓; 邓天乐; 庞伶俐
Original assignee: 华为技术有限公司
Priority date: 2015-12-30
Filing date: 2015-12-30
Publication date: 2017-07-06

Abstract

Embodiments of the present invention provide a method, apparatus and system for processing a keepalive probe packet, which relate to the field of communications and can save air-interface resources. The method comprises: a network device receives a data packet sent by a server; the network device determines the data packet as a first keepalive probe packet; the network device generates a probe response packet according to the first keepalive probe packet if the network device determines that a terminal is not restarted after the network device receives a second keepalive probe packet, wherein the second keepalive probe packet is a keepalive probe packet previous to the first keepalive probe packet; send the probe response packet to the server.

Description

Method, device and system for processing keep-alive detection message

Technical field

The present invention relates to the field of communications, and in particular, to a method, device, and system for processing keep-alive detection messages.

Background technique

With the continuous development of communication technologies, the number of clients that terminals can support is increasing. When the server needs to communicate with its corresponding client, the server first needs to know whether the client is online.

Generally, the server can determine whether the client is online by sending a keep-alive probe packet (also called a heartbeat packet) to the terminal running the client. Specifically, the server sends the keep-alive detection packet to the mobile management entity (English: mobile managementnment entity, abbreviation: MME), and the MME sends the keep-alive detection packet to the serving general packet radio service technical support node (English: serving The general packet radio service support node (abbreviation: SGSN), if the SGSN detects that the terminal is in an idle state (English: idle), the SGSN sends the keep-alive detection message to the paging controller, and the paging controller pages the The terminal, after the terminal is transferred from the idle state to the connected state (English: connect), sends the keep-alive probe message to the terminal response. If the SGSN detects that the terminal is in the connected state, the SGSN may directly send the keep-alive probe message to the terminal to respond.

However, in the process of detecting whether the client is in the online state, the SGSN directly sends the keep-alive detection packet to the terminal, so the keep-alive detection packet needs to occupy the air interface resource, in particular, multiple terminals are installed on the terminal. On the client side, as the number of keep-alive probes increases, the air interface resources are occupied in large quantities.

Summary of the invention

Embodiments of the present invention provide a method, an apparatus, and a system for processing keep-alive detection messages, which can save air interface resources.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

In a first aspect, an embodiment of the present invention provides a method for processing a keep-alive detection message, where the method includes:

The network device receives the data packet sent by the server;

Determining, by the network device, that the data packet is a first keep alive detection packet;

If the network device determines that the terminal does not restart after receiving the second keep-alive detection message, the network device generates a probe response message according to the first keep-alive detection message, where the The second keep-alive detection packet is the previous keep-alive detection packet of the first keep-alive detection packet;

The network device sends the probe response message to the server.

The method for processing the keep-alive detection packet provided by the embodiment of the present invention, after the network device receives the data packet sent by the server, and the network device determines that the data packet is the first keep-alive detection packet, if the terminal is in the network device After receiving the second keep-alive probe packet (that is, the previous keep-alive probe packet of the first keep-alive probe packet), the network device can directly generate the probe response packet according to the first keep-alive probe packet. And then sending the probe response message to the server, that is, the method for processing the keep-alive detection message provided by the embodiment of the present invention, whether the terminal is in the connected state or the idle state, if the terminal receives the second keep-alive detection on the network device After the packet is not restarted, the network device does not need to send the keep-alive detection packet to the terminal, but the network device proxy terminal replies to the server with the probe response packet in response to the keep-alive detection packet, thereby saving the network device. Air interface resources with the terminal.

Further, in an actual application, after the terminal is restarted, the originally established connection between the terminal and the server may be invalid, and the server may consider that the terminal has been disconnected from the server. Based on the situation, in the method for processing the keep-alive detection packet provided by the embodiment of the present invention, the network device needs to determine whether the terminal is restarted after receiving the second keep-alive detection packet, if the terminal has not been restarted. , the terminal and the server are always connected, that is, the client running on the terminal is always online, so that in order to save the air interface overhead between the network device and the terminal, the network device can directly receive the first security according to the The live probe packet generates a probe response packet. In this way, it also enables the network device to more accurately proxy the terminal to the server. Responding to the probe response message of the keep-alive probe message.

Optionally, the method further includes:

If the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection packet, the network device sends the first keep-alive detection packet to the terminal .

In the embodiment of the present invention, if the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection message, the network device may consider that the connection between the terminal and the network device has changed, that is, the terminal is re-established. Before the startup, the connection established between the terminal and the network device is an invalid connection. Therefore, in this case, the network device cannot reply to the probe response message of the first keep-alive detection packet to the server, but the network device The first keep-alive detection packet is sent to the terminal, and the terminal returns a probe response message in response to the first keep-alive detection packet to the server. In this way, it is possible to ensure that the server accurately knows the state of the client running on the terminal.

Optionally, the network device determines that the terminal does not restart or has been restarted after the network device receives the second keep-alive detection packet, and may be implemented by any one of the following possible implementation manners:

A possible implementation manner is: after the network device receives the second keep-alive detection message, the network device receives a non-access stratum NAS message sent by the terminal; if the NAS message does not Carrying the attach request message, the network device determines that the terminal does not restart after the network device receives the second keep-alive probe message; if the NAS message carries the attach request message, the The network device determines that the terminal has been restarted after the network device receives the second keep-alive detection message.

Another possible implementation manner is: after the network device receives the second keep-alive detection message, if the network device does not receive the attach request message sent by the core network device, the network device determines The terminal does not restart after the network device receives the second keep-alive detection message, where the attach request message is sent by the terminal to the core network device; and the network device receives the After the second keep-alive probe message is received, if the network device receives the packet sent by the core network device And the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection message.

A further possible implementation manner is: after the network device receives the second keep-alive detection message, the network device receives a radio resource control RRC connection request message sent by the terminal, the RRC connection request The message carries a re-establishment cause; if the re-establishment cause indicates that the RRC connection request message is not triggered by the terminal restarting, the network device determines that the terminal receives the second at the network device After the keep-alive probe message is not restarted; if the re-establishment cause indicates that the RRC connection request message is triggered by the terminal restarting, the network device determines that the terminal receives the location on the network device The second keep-alive probe message has been restarted.

The network device may determine whether the terminal has restarted after the network device receives the second keep-alive detection message (including no restart or has been restarted) by using any one of the foregoing possible implementation manners. . In this way, it is possible to ensure that the network device accurately knows whether the terminal has been restarted.

Optionally, after the network device receives the data packet sent by the server, the method further includes:

Determining, by the network device, that the data packet is a service data packet;

The network device sends the service data packet to the terminal.

In the embodiment of the present invention, if the network device determines that the data packet received by the network device is a service data packet, the network device may send the service data packet to the terminal, and the terminal processes the service data packet to ensure that the service data packet is processed by the terminal. The service data message terminal sent by the server to the terminal can be normally received, thereby completing communication between the server and the terminal.

In a second aspect, an embodiment of the present invention provides a network device, where the network device includes:

a receiving unit, configured to receive a data packet sent by the server;

a determining unit, configured to determine that the data packet received by the receiving unit is a first keep alive detection packet;

a generating unit, configured to: if the determining unit determines that the terminal receives at the receiving unit And after the second keep-alive detection packet is not restarted, generating a probe response packet according to the first keep-alive probe packet received by the receiving unit, where the second keep-alive probe packet is the first The previous keep-alive probe message of the keep-alive probe message;

And a sending unit, configured to send the probe response message generated by the generating unit to the server.

The embodiment of the present invention provides a network device, after the network device receives the data packet sent by the server, and the network device determines that the data packet is the first keep-alive detection packet, if the terminal receives the data packet on the network device, After the second keep-alive detection packet (that is, the previous keep-alive detection packet of the first keep-alive detection packet) is not restarted, the network device can directly generate a probe response packet according to the first keep-alive detection packet. Then, the probe response message is sent to the server, that is, the method for processing the keep-alive detection packet provided by the embodiment of the present invention, whether the terminal is in the connected state or the idle state, if the terminal receives the second keep-alive detection report on the network device After the file is not restarted, the network device does not need to send the keep-alive probe message to the terminal, but the network device proxy terminal returns a probe response message in response to the keep-alive probe message to the server, thereby saving network equipment. Air interface resources with the terminal.

Optionally, the sending unit is further configured to: if the determining unit determines that the terminal has been restarted after the receiving unit receives the second keep-alive detecting message, the first keep-alive The probe message is sent to the terminal.

Optionally, the determining unit includes a receiving module and a determining module, where

The determining unit determines that the terminal does not restart or has been restarted after the receiving unit receives the second keep-alive detection message, including:

The receiving module is configured to: after the receiving unit receives the second keep-alive detecting message, receive a non-access stratum NAS message sent by the terminal; and the determining module is configured to: if the receiving module If the received NAS message does not carry the attach request message, it is determined that the terminal does not restart after receiving the second keep-alive probe message by the receiving unit; if the NAS message received by the receiving module And carrying the attach request message, determining that the terminal has been restarted after the receiving unit receives the second keep alive detection message.

Optionally, the determining unit determines that the terminal does not restart or has been restarted after the receiving unit receives the second keep-alive detection message, and includes:

The determining unit is configured to: after the receiving unit receives the second keep-alive detecting message, if the receiving unit does not receive the attach request message sent by the core network device, determine that the terminal is in the Receiving, after receiving the second keep-alive detection message, the receiving unit does not restart, the attach request message is sent by the terminal to the core network device; and the second keep-alive detection is received by the receiving unit After the message, the receiving unit receives the attach request message sent by the core network device, and determines that the terminal has been restarted after the receiving unit receives the second keep-alive probe message.

The receiving module is configured to receive, after the receiving unit receives the second keep-alive detection message, a radio resource control RRC connection request message sent by the terminal, where the RRC connection request message carries a re-establishment cause The determining module, if the re-establishment cause received by the receiving module indicates that the RRC connection request message is not triggered by the terminal restarting, determining that the terminal receives the location at the receiving unit After the second keep-alive probe message is not restarted; if the re-establishment cause received by the receiving module indicates that the RRC connection request message is triggered by the terminal restarting, determining that the terminal is in the The receiving unit has restarted after receiving the second keep-alive detection message.

Optionally, the determining unit is further configured to: after the receiving unit receives the data packet sent by the server, determining that the data packet received by the receiving unit is a service data packet; And sending the service data packet received by the receiving unit to the terminal.

Optionally, the network device is a base station or a core network device.

The technical effects brought by the various optional manners of the foregoing second aspect are the same as those of the various alternatives in the first aspect and corresponding to the above, and may be specifically referred to The related descriptions of the technical effects brought by the various alternatives corresponding to the first aspect are not described herein again.

In a third aspect, an embodiment of the present invention provides a network device, where the network device includes a processor, an interface circuit, a memory, and a system bus.

The memory is configured to store computer execution instructions, the processor, the interface circuit, and the memory are connected to each other through the system bus, and when the network device is running, the processor executes the memory storage The computer executes the instructions to cause the network device to perform the method of processing the keep-alive detection message as described in the first aspect or the optional aspect of the first aspect.

In a fourth aspect, the embodiment of the present invention provides a communication system, where the communication system includes the network device according to any one of the foregoing second aspect or the second aspect, or Internet equipment.

The embodiment of the present invention provides a network device and a communication system, where the network system includes the network device, and when the network device receives the data packet sent by the server, the network device determines that the data packet is the first keep-alive detection. After the packet is not restarted after the network device receives the second keep-alive probe packet (that is, the previous keep-alive probe packet of the first keep-alive probe packet), the network device can directly A keep-alive probe packet generates a probe response packet, and then sends the probe response packet to the server, that is, the method for processing the keep-alive probe packet provided by the embodiment of the present invention, whether the terminal is in a connected state or an idle state, if After the network device does not restart after receiving the second keep-alive detection packet, the network device does not need to send the keep-alive detection packet to the terminal, but the network device proxy terminal responds to the server with the keep-alive detection. The packet is detected by the response packet, thereby saving air interface resources between the network device and the terminal.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is some embodiments of the invention.

1 is a schematic structural diagram of a communication system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a method for processing keep-alive detection packets according to an embodiment of the present invention; One;

FIG. 3 is a schematic diagram of a format of a data packet according to an embodiment of the present disclosure;

4 is a second schematic diagram of a method for processing keep-alive detection packets according to an embodiment of the present invention;

FIG. 5 is a schematic structural diagram 1 of a network device according to an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram 2 of a network device according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of hardware of a network device according to an embodiment of the present invention.

detailed description

The term "and/or" in this context is merely an association describing the associated object, indicating that there may be three relationships, for example, A and / or B, which may indicate that A exists separately, and both A and B exist, respectively. B these three situations. The character "/" in this article generally indicates that the contextual object is an "or" relationship. For example, A/B can be understood as A or B.

The terms "first" and "second" and the like in the specification and claims of the present invention are used to distinguish different objects, and are not intended to describe a particular order of the objects. For example, the first keep-alive detection message and the second keep-alive detection message are used to distinguish different keep-alive detection messages, instead of describing the feature sequence of the keep-alive detection message.

In the description of the present invention, the meaning of "a plurality" means two or more unless otherwise indicated. For example, multiple clients refer to two or more clients; multiple core networks refer to two or more core networks and the like.

Furthermore, the terms "comprises" and "comprising" and variations of the invention, as used in the description of the invention, are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that comprises a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units not listed, or alternatively Other steps or units inherent to these processes, methods, products or devices are included.

In the following description, for purposes of illustration and description However, it will be apparent to those skilled in the art, in other embodiments without these specific details. The invention can also be implemented. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the invention.

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, but not all embodiments.

A method for processing a keep-alive detection message according to an embodiment of the present invention may be applied to a communication system, where the communication system may be a second-generation mobile communication technology network (referred to as 2G network) and adopts a third-generation mobile communication technology. The network (referred to as 3G network), the network using the fourth generation mobile communication technology (referred to as 4G network) or the network using the fifth generation mobile communication technology (referred to as 5G network), the present invention is not specifically limited.

FIG. 1 is a schematic structural diagram of a communication system according to an embodiment of the present invention. In FIG. 1 , an example is described in which the network device is a base station, the terminal is a user equipment (English: user equipment, abbreviated as UE), and the server is an application server. Optionally, the network device in the embodiment of the present invention may also be a network device such as a core network device; the terminal may also be another type of terminal device; the server may also need to communicate with the terminal (ie, an application running on the terminal). Other servers.

Specifically, the terminal is a device that provides voice and/or data connectivity to the user, including a wireless terminal or a wired terminal. The wireless terminal can be a handheld device with wireless connectivity, or other processing device connected to a wireless modem, and a mobile terminal that communicates with one or more core networks via a wireless access network. For example, the wireless terminal can be a mobile phone (or "cellular" phone) and a computer with a mobile terminal. As another example, the wireless terminal can also be a portable, pocket, handheld, computer built-in or in-vehicle mobile device. For another example, the wireless terminal can be a mobile station (mobile station), an access point (English: access point), or a part of the UE. The specifics may be determined according to the actual application scenario, and are not specifically limited in the embodiment of the present invention.

Based on the communication system shown in FIG. 1, when the application server needs to communicate with its corresponding client (for example, the application server needs to send data to the client, ie, the application), the application server first needs to know the client. Whether it is online, usually the application server can send a keep-alive probe to the terminal running the client. The text (also known as the heartbeat packet) determines whether the client is online. When the application server sends the keep-alive detection packet to the terminal, the SGSN in the network sends the keep-alive detection packet to the terminal, and the terminal responds to the keep-alive detection packet. If the client is online, the terminal responds to the protection. After the packet is detected, the SGSN replies to the application server with the probe response packet of the keep-alive probe packet, so that the application server can learn that the client is online after receiving the probe response packet. If the application server needs to communicate with the client, the application server can send data directly to the client. If the client is offline, the terminal will not reply to the server with a probe response packet for the keep-alive probe packet, so that if the server does not receive the probe response packet replied by the terminal after the preset time, the server may Know that the client is offline.

However, since the SGSN needs to send the keep-alive probe message to the terminal response, especially when the terminal is in the connected state, it can be considered that the client running on the terminal maintains a connection state with the corresponding application server, that is, the client is in the connection state. The online status, so if the SGSN still sends the keep-alive probe message to the terminal when the terminal is in the connected state, and the terminal replies with the probe response message to the keep-alive probe message, the SGSN and the terminal are Air interface resources are occupied, especially when the number of clients is increasing, the air interface resources will be occupied a lot.

In order to save the air interface resources, the communication system provided by the embodiment of the present invention (for example, the communication system shown in FIG. 1), the embodiment of the present invention provides a method for processing a keep-alive detection message, as shown in FIG. Can include:

S101. The server sends a data packet to the network device.

S102. The network device receives a data packet sent by the server.

In the embodiment of the present invention, the data packet sent by the server to the network device may also be referred to as a downlink data packet, and the downlink data packet may be a keep-alive detection packet (or a downlink keep-alive detection packet), or It is a service data packet (or a downlink service data packet).

Optionally, the network device provided by the embodiment of the present invention may be a base station or a core network device. When the network device is a base station, the server can send the number to the core network device. According to the packet, the core network device forwards the data packet to the base station; when the network device is the core network device, the server can directly send the data packet to the core network device.

S103. The network device determines that the data packet is the first keepalive detection packet.

In this embodiment, the network device determines that the data packet is a keep-alive probe packet, where the keep-alive probe packet may also be referred to as a first keep-alive probe packet.

Optionally, in the embodiment of the present invention, the method for determining, by the network device, that the data packet is the first keepalive detection packet may be the following (1) to (5):

(1) The network device determines that the data packet carries an acknowledgement (English: acknowledgement, abbreviation: ACK); (2) the network device determines that the data packet is a data packet without a data payload or the data packet is a data message with an invalid data payload of 1 byte; (3) the network device determines that the data sequence number of the data packet is the data sequence number of the next service data packet to be transmitted minus 1; (4) network The device determines that the ACK is set to confirm that the sequence number is valid (for example, the ACK is set to 1 to indicate that the acknowledgment sequence number is valid); (5) the network device determines that the acknowledgment sequence number of the data message is set to the next acknowledgment sequence number that the server expects to receive.

The network device determines that the data sequence number of the data packet is the data sequence number of the next service data packet to be sent minus one, which can be understood as:

The network device determines that the data sequence number of the data packet is the number of bytes that have been confirmed to be successfully transmitted minus one. Specifically, the network device may determine that the data sequence number of the data packet is the acknowledgement sequence number of the uplink service data packet minus one by detecting the uplink service data packet that carries the ACK flag.

It should be noted that, if the data packet received by the network device meets the foregoing (1) to (5), the network device may determine that the data packet is a keep-alive detection packet (ie, the first keep-alive detection packet). If the data packet received by the network device does not satisfy at least one of the foregoing (1) to (5), the network device determines that the data packet is not a keep-alive probe message.

Further, in order to better understand that the network device determines that the received data packet is a keep-alive probe packet, the format of the data packet is exemplarily described below.

The data packet in the embodiment of the present invention may be a transmission control protocol/Internet protocol. (English: transmission control protocol/Internet protocol, abbreviation: TCP/IP) data message, the format of the TCP/IP data message is shown in Figure 3. The TCP/IP data packet shown in FIG. 3 includes three parts: an IP header, a TCP header, and a data payload. The following is an example of each of the three fields.

IP header:

Version: refers to the current protocol version number. For example, it can be 4, which is IPv4.

Head length: refers to the number of 32-bit (English: bit) words occupied by the IP header.

Type of service (TOS): consists of 8 bits, including the 3-bit priority subfield, the 4-bit TOS subfield and the 1-bit unused bit (which must be set to 0). The 4bit TOS subfields are respectively Represents minimum latency, maximum throughput, maximum reliability, and minimum cost.

Total length: refers to the length of the entire data packet.

ID: Each data packet sent by the host (ie, the sender, which is a server in the embodiment of the present invention) is uniquely identified.

Flag: It consists of 3 bits, including 1bit unused, 1bit setting whether to allow segmentation, and 1bit indicating whether there is still a segment for router to segment data packets.

Segment Offset: Indicates the location of this segment in the current data message.

Time to live (English: time to live, abbreviation: TTL): Sets the maximum number of routers that data packets can pass.

Protocol code: Indicates which transmission process the data message belongs to, such as TCP or user datagram protocol (abbreviation: UDP).

Header checksum: Only verifies the header, that is, generates a checksum based on the contents of other fields in the header.

Source address and destination address: Indicates the network number and host number of the source and destination, that is, the source IP address and the destination IP address.

TCP header:

Source port number and destination port number: used to find the application process of the sender and receiver. These two values plus the source IP address and the destination IP address in the IP header uniquely identify a TCP connection.

Data sequence number: represents the serial number of the first byte of the TCP connection. Specifically, when establishing a new TCP connection, the host selects an initial sequence number, and the first byte sequence number sent is the initial sequence number plus one.

Confirmation sequence number: indicates the serial number of the number of bytes sent correctly by the peer.

Head length: refers to the number of 32-bit words occupied by the header of the TCP header.

Reserved: Refers to the reserved field.

Emergency position (English: urgent, abbreviation: URG): Indicates whether the emergency pointer is valid. Let one end tell the other end that there is some kind of urgent data (such as the data when the user types the interrupt key or the user abandons the transfer of a file) has been placed in the normal data stream.

ACK: Indicates whether the serial number is valid.

Transmission (English: push, abbreviation: PSH): Indicates whether the receiver should transmit this message to the application layer as soon as possible.

Reset (English: reset, abbreviation: RST): Indicates whether to re-establish the connection.

Establish online (English: synchronous, abbreviation: SYN): Indicates whether to initiate a connection.

End (English: finish, abbreviation: FIN): Indicates whether the sender completes the sending task.

Window field: TCP's flow control is provided by the window size declared at each end. This value is the byte that the receiver expects to receive.

Packet checksum: Verify the TCP header and TCP data.

Emergency Pointer: Adds the value in the Data Sequence Number field to indicate the sequence number of the last byte of the urgent data.

Data payload: Indicates the payload of a TCP/IP data packet, that is, the data that the TCP/IP data packet needs to transmit.

In the embodiment of the present invention, the network device determines, in the method that the received data packet is the first keep alive detection packet, the ACK, the data payload, the data sequence number, the confirmation sequence number, and the specific settings thereof. For details, refer to the related description of the corresponding fields in the TCP/IP data packet, and details are not described here.

S104. If the network device determines that the terminal does not restart after receiving the second keep-alive detection packet, the network device generates a probe response packet according to the first keep-alive detection packet.

The first keep-alive detection packet and the second keep-alive detection packet are the keep-alive detection packets received by the network device twice, and the second keep-alive detection packet is the first keep-alive detection packet. The previous keep-alive probe message. The second keep-alive detection packet is the keep-alive detection packet received by the network device before receiving the first keep-alive detection packet. Specifically, the network device first receives the second keep-alive detection packet, and then the network The device receives the first keep-alive detection packet again.

In an actual application, after the terminal is restarted, the original established connection between the terminal and the server may be invalid. At this time, the network device may think that the terminal has been disconnected from the server. Based on the situation, in the method for processing the keep-alive detection packet provided by the embodiment of the present invention, the network device needs to determine whether the terminal is restarted after receiving the second keep-alive detection packet, if the terminal has not been restarted. , the terminal and the server are always connected, that is, the client running on the terminal is always online, so that in order to save the air interface overhead between the network device and the terminal, the network device can directly receive the first security according to the The live probe packet generates a probe response packet. In this way, the network device can also make the proxy device more accurately return the probe response message to the server in response to the keep-alive probe message.

Optionally, in the method for processing the keep-alive detection packet, the format of the probe response packet is the same as the format of the keep-alive probe packet. That is, the format of the probe response packet can also be seen in the format of the TCP/IP data packet as shown in FIG.

Optionally, the method for the network device to generate the probe response packet according to the first keepalive detection packet may be:

After the network device generates a new data packet, the ACK in the data packet is set to 1 (that is, the acknowledgment sequence number carried in the data packet is valid); the acknowledgment sequence number in the data packet is set to be the received acknowledgment number. The value of the data sequence number in the keep-alive detection message is incremented by one; the data sequence number in the data message is set to the acknowledgement sequence number in the first keep-alive probe message received; for other data packets Field settings, network devices The network device may set the value of the field of the data packet received by the network device, or the network device may obtain the value of some field in the data packet, and then the network device sets the calculated result to the corresponding field. Thus, the network device can generate a probe response message in response to the first keep-alive probe message.

Except for the ACK, the acknowledgment sequence number and the data sequence number in the data packet, the version, service type, flag, lifetime, protocol code, source address, destination address, source port number, The destination port number, the reserved, the window field, and the like may be set by the network device to be the same as the content of the corresponding field in the uplink service data packet received within a certain period of time; the segment offset and the segment in the data packet The URG or the like may be set to 0 by the network device; the header length, the total length, the header checksum, and the packet checksum in the data packet may be calculated by the network device according to the specific meaning of the fields, and then the network device According to the calculation result, the header length, the total length, the header checksum, and the packet checksum in the data packet are set; the URG, PSH, RST, SYN, and FIN in the data packet can be set by the network device. It is 0 and so on.

It should be noted that, because the identifier in the IP header is unique in each IP header, in the embodiment of the present invention, the identifier in the probe response packet generated by the network device proxy terminal may be related to the uplink service datagram generated by the terminal. In the embodiment of the present invention, when the network device generates the probe response packet, the identifier is the same as the identifier of the traffic data packet sent by the terminal to the server. The random number corresponding to the identifier in the uplink service data packet received by the last time is generated, and then the random number is set as the identifier of the probe response message.

Specifically, in the embodiment of the present invention, the random number generated by the network device and the identifier of the uplink service data packet received by the network device is relatively large, and can be implemented by any of the following methods:

(1) After the network device generates a random number, compare the random number with the identifier in the uplink service data packet received last time, if the difference between the two is relatively large (for example, the absolute value of the difference is greater than or equal to a preset threshold, which may be set according to actual usage requirements, which is not specifically limited by the present invention, and the random number is As the identifier of the probe response message; if the difference between the two is relatively small (for example, the absolute value of the difference between the two is less than the preset threshold), a random number is regenerated, until the difference between the two is relatively large, the last generated The random number is used as the identifier of the probe response message.

(2) The network device generates a plurality of random numbers, and determines, in the plurality of random numbers, a random number having the largest difference from the identifier in the uplink service data packet received last time (for example, the identifier is included in the plurality of random numbers) The absolute value of the difference is the largest random number), and then the network device uses the random number as the identifier of the probe response message.

Certainly, in the embodiment of the present invention, the method for the network device to generate a random number that is relatively different from the identifier of the uplink service data packet received last time includes, but is not limited to, the foregoing (1) and (2), that is, the network. The device generates a random number that is different from the identifier of the uplink service data packet that is received by the device, and can be implemented in other manners, which is not described in the embodiment of the present invention.

Optionally, the method for determining, by the network device, that the terminal does not restart after the network device receives the second keep alive detection packet is described in detail in the following embodiments, and details are not described herein again.

S105. The network device sends a probe response message to the server.

S106. The server receives the probe response packet sent by the network device.

After the network device generates the probe response packet according to the first keep-alive probe packet, the network device may send the probe response packet to the server. After receiving the probe response packet, the server may learn that the client is online.

The method for processing the keep-alive detection packet provided by the embodiment of the present invention, after the network device receives the data packet sent by the server, and the network device determines that the data packet is the first keep-alive detection packet, if the terminal is in the network device After receiving the second keep-alive probe packet (that is, the previous keep-alive probe packet of the first keep-alive probe packet), the network device can directly generate the probe response packet according to the first keep-alive probe packet. And then sending the probe response message to the server, that is, the method for processing the keep-alive detection message provided by the embodiment of the present invention, whether the terminal is in the connected state or the idle state, if the terminal receives the second keep-alive detection on the network device After the packet is not restarted, the network device does not need to send the keep-alive probe packet to the terminal, but the network device proxy terminal sends the service to the terminal. The server responds to the probe response packet of the keep-alive probe packet, thereby saving air interface resources between the network device and the terminal.

Optionally, in conjunction with FIG. 2, as shown in FIG. 4, the method for processing the keep-alive detection packet provided by the embodiment of the present invention may further include:

S107. If the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection packet, the network device sends the first keep-alive detection packet to the terminal.

S108. The terminal receives the first keep-alive detection packet sent by the network device.

It should be noted that, in the embodiment of the present invention, the above-mentioned S104-S106 and S107-S108 are alternatively executed; that is, after S101-S103 is executed, S104-S106 is executed or S107-S108 is executed. In order to indicate that S104-S106 and S107-S108 are alternatively performed, S104-S106 and S107-S108 are both shown in broken lines in FIG.

Optionally, the method for processing the keep-alive detection packet provided by the embodiment of the present invention may further include:

S109. The terminal generates a probe response packet according to the first keepalive detection packet.

S110. The terminal sends a probe response packet to the network device.

S111. The network device receives the probe response packet sent by the terminal.

S112. The network device sends a probe response message to the server.

S113. The server receives a probe response packet sent by the network device.

It should be noted that, in the embodiment of the present invention, after the network device sends the first keep-alive detection packet to the terminal, the terminal processes the first keep-alive detection packet, that is, the foregoing S109-S113 and the normal terminal response server send the packet. The method for keeping the probe packet is similar, and is not described in detail in the embodiment of the present invention.

In the embodiment of the present invention, if the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection packet, the network device may consider that the connection between the terminal and the server has changed, that is, restart the terminal. The connection established between the terminal and the server is already an invalid connection. In this case, the network device cannot reply to the probe response packet of the first keep-alive probe message to the server, but the network device The first keep-alive detection message is sent to the terminal, and the terminal returns a probe response message in response to the first keep-alive detection message to the server. So, can Ensure that the server accurately knows the state of the client running on the terminal.

Optionally, in the method for processing the keep-alive detection packet, the network device determines that the terminal does not restart or has been restarted after the network device receives the second keep-alive detection packet, which may be specifically described below. Any method to achieve:

A possible implementation manner is: after the network device receives the second keep-alive detection message, the network device receives a non-access stratum (English: non-access stratum, abbreviation: NAS) message sent by the terminal; if the NAS message If the network device does not carry the attach request message, the network device determines that the terminal does not restart after the network device receives the second keep-alive probe message; if the NAS message carries the attach request message, the network device determines that the terminal receives the first The second keep-alive probe message has been restarted.

Another possible implementation manner is: after the network device receives the second keep-alive probe message, if the network device does not receive the attach request message sent by the core network device, the network device determines that the terminal receives the second device on the network device. After the keepalive detection packet is not restarted, the attach request message is sent by the terminal to the core network device; after the network device receives the second keep alive detection packet, if the network device receives the attach request sent by the core network device The message, the network device determines that the terminal has restarted after the network device receives the second keep alive detection message.

A further possible implementation manner is: after the network device receives the second keep-alive detection message, the network device receives a radio resource control (English: radio resource control, abbreviation: RRC) connection request message sent by the terminal, where the RRC connection The request message carries the re-establishment cause; if the re-establishment cause indicates that the RRC connection request message is not triggered by the terminal restarting, the network device determines that the terminal does not restart after receiving the second keep-alive detection message by the network device; The re-establishment cause indicates that the RRC connection request message is triggered by the terminal restarting, and the network device determines that the terminal has restarted after the network device receives the second keep-alive detection message.

A person skilled in the art may understand that the foregoing network device determines that the terminal does not restart or has restarted after the network device receives the second keep-alive detection message, and the time period after the network device receives the second keep-alive detection message is The time period after the network device receives the second keep-alive probe message, and the network device performs S104.

Optionally, in the method for processing the keep-alive detection packet, when the network device receives the data packet sent by the server, if the network device determines that the data packet is a service data packet, the network device The service data packet can be sent to the terminal, and the service data packet is processed by the terminal, so that the service data packet terminal sent by the server to the terminal can be normally received, thereby completing communication between the server and the terminal.

As shown in FIG. 5, an embodiment of the present invention provides a network device, where the network device is configured to perform the steps performed by the network device in the method in the foregoing embodiment. The network device may include a module corresponding to the corresponding step. Exemplarily, the network device includes:

The receiving unit 10 is configured to receive a data packet sent by the server, and the determining unit 11 is configured to determine that the data packet received by the receiving unit 10 is a first keep-alive detecting packet, and the generating unit 12 is configured to: The determining unit 11 determines that the terminal does not restart after the receiving unit 10 receives the second keep-alive detecting message, and generates a probe response message according to the first keep-alive detecting message received by the receiving unit 10, The second keep-alive detection packet is the previous keep-alive detection packet of the first keep-alive detection packet, and the sending unit 13 is configured to send the probe response packet generated by the generating unit 12 to The server.

Optionally, the sending unit 13 is further configured to: if the determining unit 11 determines that the terminal has been restarted after the receiving unit 10 receives the second keep-alive detecting message, A keep-alive detection message is sent to the terminal.

Optionally, in conjunction with FIG. 5, as shown in FIG. 6, the determining unit 11 includes a receiving module 110 and a determining module 111.

The determining unit 11 determines that the terminal does not restart or has been restarted after the receiving unit 10 receives the second keep-alive detecting message, and includes:

The receiving module 110 is configured to receive the NAS message sent by the terminal after the receiving unit 10 receives the second keep-alive detecting message, and the determining module 111 is configured to: if the receiving module 110 The received NAS message does not carry The request message is determined, the terminal is not restarted after the receiving unit 10 receives the second keep-alive detection message; if the NAS message received by the receiving module 110 carries the attach request message And determining that the terminal has been restarted after the receiving unit 10 receives the second keep-alive detection message.

Optionally, the determining unit 11 determines that the terminal does not restart or has been restarted after the receiving unit 10 receives the second keep-alive detection message, and includes:

The determining unit 11 is configured to: after the receiving unit 10 receives the second keep-alive detecting message, if the receiving unit 10 does not receive the attach request message sent by the core network device, determine the terminal After the receiving unit 10 receives the second keep-alive detecting message, the attach request message is sent by the terminal to the core network device; and the receiving unit 10 receives the After the second keepalive detection message, if the receiving unit 10 receives the attach request message sent by the core network device, it is determined that the terminal receives the second keep-alive detection at the receiving unit 10 The message has been restarted afterwards.

The receiving module 110 is configured to receive, after the receiving unit 10 receives the second keep-alive detecting message, an RRC connection request message sent by the terminal, where the RRC connection request message carries a re-establishment cause; The determining module 111 is configured to: if the re-establishment cause received by the receiving module 110 indicates that the RRC connection request message is not triggered by the terminal restarting, determine that the terminal receives at the receiving unit 10 Not restarting after the second keep-alive detection message; if the re-establishment reason received by the receiving module 110 indicates that the RRC connection request message is triggered by the terminal restarting, determining the terminal After the receiving unit 10 receives the second keep-alive probe message, it has been restarted.

Optionally, the determining unit 11 is further configured to receive the service at the receiving unit 10 After the data packet sent by the server, the data packet received by the receiving unit 10 is determined to be a service data packet; the sending unit 13 is further configured to send the service data packet received by the receiving unit 10 The text is sent to the terminal.

Optionally, in the embodiment of the present invention, the network device is a base station or a core network device.

It can be understood that the network device in this embodiment may correspond to the network device in the method for processing the keep-alive detection message in the foregoing embodiment of FIG. 2 or FIG. 4, and the modules in the network device in this embodiment The division and/or function are all for the implementation of the method flow shown in FIG. 2 or FIG. 4, and for brevity, no further details are provided herein.

The network device provided by the embodiment of the present invention, after the network device receives the data packet sent by the server, and the network device determines that the data packet is the first keep-alive detection packet, if the terminal receives the data packet on the network device After the second keep-alive probe packet (that is, the previous keep-alive probe packet of the first keep-alive probe packet) is not restarted, the network device can directly generate a probe response packet according to the first keep-alive probe packet, and then And sending the probe response packet to the server, that is, the method for processing the keep-alive detection packet provided by the embodiment of the present invention, whether the terminal receives the second keep-alive detection packet on the network device, whether the terminal is in the connected state or the idle state. After the network device does not need to restart, the network device does not need to send the keep-alive detection packet to the terminal, but the network device proxy terminal responds to the server with the probe response packet in response to the keep-alive detection packet, thereby saving network equipment and Air interface resources between terminals.

As shown in FIG. 7, an embodiment of the present invention provides a network device, which may include a processor 20, an interface circuit 21, a memory 22, and a system bus 23.

The memory 22 is configured to store computer execution instructions, the processor 20, the interface circuit 21 and the memory 22 are connected to each other through the system bus 23, and when the network device is running, the processor 20 executes The computer stored by the memory 22 executes an instruction to cause the network device to perform a method of processing a keep-alive probe message as shown in FIG. 2 or FIG. For a specific method for processing the keep-alive detection packet, refer to the related description in the foregoing embodiment shown in FIG. 2 or FIG. 4, and details are not described herein again.

The embodiment further provides a storage medium, which may include the storage Device 22.

The processor 20 can be a central processing unit (English: central processing unit, abbreviation: CPU). The processor 20 can also be other general-purpose processors, digital signal processing (DSP), application specific integrated circuit (ASIC), field programmable gate array (English) : field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like.

The processor 20 may be a dedicated processor, which may include at least one of a baseband processing chip, a radio frequency processing chip, and the like. Further, the dedicated processor may also include a chip having other dedicated processing functions of the network device.

The memory 22 may include a volatile memory (English: volatile memory) (English: random-access memory, abbreviation: RAM); the memory 22 may also include a non-volatile memory (English: Non-volatile memory, such as read-only memory (English: read-only memory, abbreviation: ROM), flash memory (English: flash memory), hard disk (English: hard disk drive, abbreviation: HDD) or solid state drive (English) : solid-state drive, abbreviated: SSD); the memory 22 may also include a combination of the above types of memories.

The system bus 23 can include a data bus, a power bus, a control bus, a signal status bus, and the like. For the sake of clarity in the present embodiment, various buses are illustrated as the system bus 23 in FIG.

The interface circuit 21 may specifically be a transceiver on a network device. The transceiver can be a wireless transceiver. For example, the wireless transceiver can be an antenna of a network device or the like. The processor 20 performs data transmission and reception with the other device, such as the terminal, through the interface circuit 21.

In a specific implementation process, each step in the method flow shown in FIG. 2 or FIG. 4 can be implemented by the processor 20 in hardware form executing a computer-executed instruction in the form of software stored in the memory 22. To avoid repetition, we will not repeat them here.

The embodiment of the present invention provides a communication system, which may include the network device shown in FIG. 5 or FIG. 6 above; or the communication system may include the network device shown in FIG. 7 above. For a detailed description of the network device, refer to the related description of the network device in the foregoing embodiment shown in FIG. 5, FIG. 6 or FIG. 7, and details are not described herein again.

Optionally, the communication system of the embodiment of the present invention may be a communication system as shown in FIG. 1. The communication system may include a terminal, a base station, and a server. The network device provided by the embodiment of the present invention may be a base station in the communication system as shown in FIG. 1 or a core network device (the network device is a base station in FIG. 1 and the core network device is not shown). It can be determined according to the actual application scenario, which is not limited by the embodiment of the present invention.

The embodiment of the present invention provides a communication system, where the communication system includes a network device, and if the network device receives the data packet sent by the server, and the network device determines that the data packet is the first keep-alive detection packet, After the network device does not restart after receiving the second keep-alive probe packet (that is, the previous keep-alive probe packet of the first keep-alive probe packet), the network device may directly report the first keep-alive probe according to the first keep-alive probe packet. Generate a probe response message, and then send the probe response message to the server, that is, the hair The method for processing the keep-alive detection packet provided by the embodiment, whether the terminal is in the connected state or the idle state, if the terminal does not restart after the network device receives the second keep-alive detection packet, the network device does not need to be protected again. The live detection packet is sent to the terminal, and the network device proxy terminal returns a probe response message in response to the keep-alive detection packet to the server, thereby saving air interface resources between the network device and the terminal.

Through the description of the above embodiments, those skilled in the art can clearly understand that for the convenience and brevity of the description, only the division of the above functional modules is illustrated. In practical applications, the above functions can be allocated according to needs. It is completed by different functional modules, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. For the specific working process of the system, the device and the unit described above, reference may be made to the corresponding process in the foregoing method embodiments, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be used. Combinations can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or all or part of the technical solution, may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

A method for processing a keep-alive detection message, the method comprising:

The network device receives the data packet sent by the server;

Determining, by the network device, that the data packet is a first keep alive detection packet;

If the network device determines that the terminal does not restart after receiving the second keep-alive detection message, the network device generates a probe response message according to the first keep-alive detection message, where the The second keep-alive detection packet is the previous keep-alive detection packet of the first keep-alive detection packet;

The network device sends the probe response message to the server.
The method of claim 1 further comprising:

If the network device determines that the terminal has been restarted after the network device receives the second keep-alive detection packet, the network device sends the first keep-alive detection packet to the terminal .
The method according to claim 2, wherein the network device determines that the terminal does not restart or has restarted after the network device receives the second keep-alive detection message, by using the following method achieve:

After the network device receives the second keep-alive probe message, the network device receives the non-access stratum NAS message sent by the terminal;

If the NAS message does not carry the attach request message, the network device determines that the terminal does not restart after the network device receives the second keep-alive probe message;

If the NAS message carries the attach request message, the network device determines that the terminal has been restarted after the network device receives the second keep-alive probe message.
The method according to claim 2, wherein the network device determines that the terminal does not restart or has restarted after the network device receives the second keep-alive detection message, by using the following method achieve:

After the network device receives the second keep-alive probe message, if the network device does not receive the attach request message sent by the core network device, the network device does Determining that the terminal does not restart after the network device receives the second keep-alive detection message, where the attach request message is sent by the terminal to the core network device;

After the network device receives the second keep-alive probe message, if the network device receives the attach request message sent by the core network device, the network device determines that the terminal is in the The network device has restarted after receiving the second keep-alive probe message.
The method according to claim 2, wherein the network device determines that the terminal does not restart or has restarted after the network device receives the second keep-alive detection message, by using the following method achieve:

After the network device receives the second keep-alive detection message, the network device receives a radio resource control RRC connection request message sent by the terminal, where the RRC connection request message carries a re-establishment cause;

If the re-establishment cause indicates that the RRC connection request message is not triggered by the terminal restarting, the network device determines that the terminal does not after the network device receives the second keep-alive detection message. Restart;

If the re-establishment cause indicates that the RRC connection request message is triggered by the terminal restarting, the network device determines that the terminal has been after the network device receives the second keep-alive detection message. Restart.
The method according to any one of claims 1 to 5, wherein after the network device receives the data packet sent by the server, the method further includes:

Determining, by the network device, that the data packet is a service data packet;

The network device sends the service data packet to the terminal.
A network device, where the network device includes:

a receiving unit, configured to receive a data packet sent by the server;

a determining unit, configured to determine that the data packet received by the receiving unit is a first keep alive detection packet;

a generating unit, configured to: if the determining unit determines that the terminal does not restart after receiving the second keep-alive detecting message, the detecting unit generates a probe according to the first keep-alive detecting message received by the receiving unit In response to the message, the second keep-alive probe message is The previous keep-alive detection message of the first keep-alive detection message;

And a sending unit, configured to send the probe response message generated by the generating unit to the server.
The network device according to claim 7, wherein

The sending unit is further configured to: if the determining unit determines that the terminal has been restarted after the receiving unit receives the second keep-alive detecting message, sending the first keep-alive detecting message To the terminal.
The network device according to claim 8, wherein the determining unit comprises a receiving module and a determining module,

The determining unit determines that the terminal does not restart or has been restarted after the receiving unit receives the second keep-alive detection message, including:

The receiving module is configured to receive, after the receiving unit receives the second keep-alive detection message, a non-access stratum NAS message sent by the terminal;

The determining module is configured to: if the NAS message received by the receiving module does not carry an attach request message, determine that the terminal does not restart after the receiving unit receives the second keep-alive detecting message If the NAS message received by the receiving module carries the attach request message, it is determined that the terminal has been restarted after the receiving unit receives the second keep-alive detecting message.
A network device according to claim 8, wherein

The determining unit determines that the terminal does not restart or has been restarted after the receiving unit receives the second keep-alive detection message, including:

The determining unit is configured to: after the receiving unit receives the second keep-alive detecting message, if the receiving unit does not receive the attach request message sent by the core network device, determine that the terminal is in the Receiving, after receiving the second keep-alive detection message, the receiving unit does not restart, the attach request message is sent by the terminal to the core network device; and the second keep-alive detection is received by the receiving unit After the message, the receiving unit receives the attach request message sent by the core network device, and determines that the terminal has been restarted after the receiving unit receives the second keep-alive probe message.
The network device according to claim 8, wherein the determining unit comprises a receiving module and a determining module,

The determining unit determines that the terminal does not restart or has been restarted after the receiving unit receives the second keep-alive detection message, including:

The receiving module is configured to receive, after the receiving unit receives the second keep-alive detection message, a radio resource control RRC connection request message sent by the terminal, where the RRC connection request message carries a re-establishment cause ;

Determining, by the determining module, if the re-establishment cause received by the receiving module indicates that the RRC connection request message is not triggered by the terminal restarting, determining that the terminal receives the After the second keepalive detection message is not restarted; if the reestablishment reason received by the receiving module indicates that the RRC connection request message is triggered by the terminal restarting, determining that the terminal is in the receiving The unit has restarted after receiving the second keep-alive probe message.
A network device according to any one of claims 7 to 11, wherein

The determining unit is further configured to: after the receiving unit receives the data packet sent by the server, determine that the data packet received by the receiving unit is a service data packet;

The sending unit is further configured to send the service data packet received by the receiving unit to the terminal.
A network device according to any one of claims 7 to 12, characterized in that

The network device is a base station or a core network device.
A network device, comprising: a processor, an interface circuit, a memory, and a system bus;

The memory is configured to store computer execution instructions, the processor, the interface circuit, and the memory are connected to each other through the system bus, and when the network device is running, the processor executes the memory storage The computer executes instructions to cause the network device to perform the method of processing a keep-alive probe message according to any one of claims 1 to 6.
A communication system, comprising: the network device according to any one of claims 7 to 13; or the network device according to claim 14.