Message transmission method, user plane function, SMF and communication equipment

Abstract

The present invention provides a message transmission method, user plane function, SMF, and communication equipment. A core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2. A first user plane function is the first user plane function that a message arrives at in the core network user plane forwarding path. The message transmission method performed by the first user plane function includes: receiving an Internet Protocol (IP) header enhancement message construction rule sent by a session management function (SMF); generating a first IP header enhancement message based on the IP header enhancement message construction rule, the first IP header enhancement message including the addresses of all user plane functions in the N user plane functions except the first user plane function; and sending the first IP header enhancement message. The present invention breaks the hop-by-hop tunneling mechanism and can reduce the complexity of message transmission.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a message transmission method, a user plane function, an SMF, and a communication device. Background Art

[0002] In the research on Segment Routing over IPv6 data plane (SRv6), N9 (between user plane functions) is introduced to support the SRv6 mechanism.

[0003] To minimize the impact on existing user plane functions, the SRv6 mechanism is designed to follow the General Packet Radio Service Tunneling Protocol-User Plane (GTP-U) tunneling mechanism, which configures tunnels on a hop-by-hop basis. Consequently, each user plane function currently uses a separate hop, leading to increased message transmission complexity. Summary of the Invention

[0004] The embodiments of the present invention provide a message transmission method, a user plane function, an SMF and a communication device to solve the problem of high complexity of existing message transmission.

[0005] To solve the above-mentioned technical problems, the present invention is achieved as follows:

[0006] In a first aspect, an embodiment of the present invention provides a message transmission method, which is performed by a first user plane function, where the first user plane function is the first user plane function at which the message arrives in a core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; the method includes:

[0007] Receive the Internet Protocol IP header enhancement message construction rules sent by the session management function SMF;

[0008] Generate a first IP header enhanced message according to the IP header enhanced message construction rule, where the first IP header enhanced message includes addresses of all other user plane functions among the N user plane functions except the first user plane function;

[0009] Send the first IP header enhanced message.

[0010] In a second aspect, an embodiment of the present invention provides a message transmission method, which is performed by a second user plane function, where the second user plane function is the i-th user plane function at which the message arrives in the core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2, and i is an integer greater than 1 and less than N; the method includes:

[0011] Receive a second IP header enhanced message sent by an i-1th user plane function in the core network user plane forwarding path, where the segment address list of the second IP header enhanced message includes addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path;

[0012] Generate a third IP header enhanced message according to the second IP header enhanced message, wherein the segment address list of the third IP header enhanced message includes addresses of all subsequent user plane functions in the core network user plane forwarding path that are located after the i-th user plane function;

[0013] Send the third IP header enhanced message.

[0014] In a third aspect, an embodiment of the present invention provides a message transmission method, which is performed by a third user plane function, wherein the third user plane function is the last user plane function at which the message arrives in the core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; the method includes:

[0015] Receive a fourth IP header enhanced message sent by an N-1th user plane function in the core network user plane forwarding path, where the segment address list of the fourth IP header enhanced message includes addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path;

[0016] Generating a target message according to the fourth IP header enhanced message;

[0017] Sending the target message to the target network;

[0018] Wherein, when the target message is an IP message, the target network is a data network; when the target message is a GTP-U message, the target network is a wireless access network.

[0019] In a fourth aspect, an embodiment of the present invention provides a message transmission method, which is executed by SMF, and the method includes:

[0020] Determine, based on at least one of the terminal's location information, a network policy, a network slice identifier, and a data network name, a core network user plane forwarding path associated with the first terminal, where the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2;

[0021] Send an IP header enhancement message construction rule to the first user plane function, where the IP header enhancement message construction rule is used to generate a first IP header enhancement message. The first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function. The first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

[0022] In a fifth aspect, an embodiment of the present invention provides a user plane function as a first user plane function, wherein the first user plane function is the first user plane function at which a message arrives in a core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; the user plane function includes:

[0023] A first transceiver is configured to receive an Internet Protocol IP header enhanced message construction rule sent by a session management function SMF;

[0024] a first processor, configured to generate a first IP header enhancement message according to the IP header enhancement message construction rule, where the first IP header enhancement message includes addresses of all other user plane functions among the N user plane functions except the first user plane function;

[0025] The first transceiver is also used to send the first IP header enhanced message.

[0026] In a sixth aspect, an embodiment of the present invention provides a user plane function as a second user plane function, the second user plane function being the i-th user plane function at which the message arrives in the core network user plane forwarding path, the core network user plane forwarding path including N user plane functions, N is an integer not less than 2, i is an integer greater than 1 and less than N; the user plane function includes:

[0027] A second transceiver is configured to receive a second IP header enhanced message sent by an i-1th user plane function in the core network user plane forwarding path, where the segment address list of the second IP header enhanced message includes addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path;

[0028] a second processor, configured to generate a third IP header enhanced message according to the second IP header enhanced message, wherein the segment address list of the third IP header enhanced message includes addresses of all subsequent user plane functions in the core network user plane forwarding path that are located after the i-th user plane function;

[0029] The second transceiver is used to send the third IP header enhanced message.

[0030] In a seventh aspect, an embodiment of the present invention provides a user plane function as a third user plane function, wherein the third user plane function is the last user plane function at which a message arrives in a core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; the user plane function includes:

[0031] A third transceiver is configured to receive a fourth IP header enhanced message sent by the N-1th user plane function in the core network user plane forwarding path, where the segment address list of the fourth IP header enhanced message includes addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path;

[0032] A third processor is configured to generate a target message according to the fourth IP header enhanced message;

[0033] The third transceiver is used to send the target message to the target network;

[0034] Wherein, when the target message is an IP message, the target network is a data network; when the target message is a GTP-U message, the target network is a wireless access network.

[0035] In an eighth aspect, an embodiment of the present invention provides an SMF, wherein the SMF includes:

[0036] a fourth processor, configured to determine, based on at least one of the terminal's location information, a network policy, a network slice identifier, and a data network name, a core network user plane forwarding path associated with the first terminal, the core network user plane forwarding path including N user plane functions, where N is an integer not less than 2;

[0037] A fourth transceiver is used to send an IP header enhancement message construction rule to the first user plane function, where the IP header enhancement message construction rule is used to generate a first IP header enhancement message, where the first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function, and the first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

[0038] In the ninth aspect, an embodiment of the present invention provides a communication device, comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the method described in the first aspect, the second aspect, the third aspect, or the fourth aspect.

[0039] In the tenth aspect, an embodiment of the present invention provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect, the second aspect, the third aspect or the fourth aspect are implemented.

[0040] In this embodiment of the present invention, after determining the core network user plane forwarding path, the SMF sends an IP header enhancement message construction rule determined based on the core network user plane forwarding path to the first user plane function in the core network user plane forwarding path where the packet arrives. This first user plane function can then generate a first IP header enhancement message, which includes the addresses of all other user plane functions among the N user plane functions except the first one, and pass the generated IP header enhancement message to the next user plane function. After receiving the IP header enhancement message, the next user plane function can determine whether it is the last user plane function in the core network user plane forwarding path. If not, it can generate a new IP header enhancement message based on the received IP header enhancement message and pass the generated IP header enhancement message to the next user plane function. If so, it can reconstruct the IP header enhancement message into a target message and send it to the target network. This embodiment of the present invention breaks the hop-by-hop tunneling mechanism. Each user plane function in the core network user plane forwarding path can determine the next recipient of a message based on the received IP header enhancement message, thereby reducing the complexity of message transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0042] Figure 1 is a structural diagram of a network system to which an embodiment of the present invention can be applied;

[0043] Figure 2 This is one of the flow charts of the message transmission method provided by an embodiment of the present invention;

[0044] Figure 3 This is the second flowchart of the message transmission method provided by an embodiment of the present invention;

[0045] Figure 4 This is the third flowchart of the message transmission method provided by an embodiment of the present invention;

[0046] Figure 5 This is the fourth flowchart of the message transmission method provided by an embodiment of the present invention;

[0047] Figure 6 This is one of the schematic diagrams of message transmission provided by an embodiment of the present invention;

[0048] Figure 7 This is the second schematic diagram of message transmission provided by an embodiment of the present invention;

[0049] Figure 8 This is one of the structural diagrams of the user plane function provided by an embodiment of the present invention;

[0050] Figure 9 This is the second structural diagram of the user plane function provided by an embodiment of the present invention;

[0051] Figure 10 This is the third structural diagram of the user plane function provided by an embodiment of the present invention;

[0052] Figure 11 1 is a structural diagram of the SMF provided by an embodiment of the present invention;

[0053] Figure 12 It is a structural diagram of a communication device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] See Figure 1 , Figure 1 This is a structural diagram of a network system to which the embodiment of the present invention can be applied. Figure 1 As shown, it includes the Radio Access Network (RAN), the core network user plane forwarding path, the Data Network (DN) and the Session Management Function (SMF).

[0056] A core network user plane forwarding path includes at least two user plane functions. User plane functions in the core network user plane forwarding path can communicate with each other and transmit Internet Protocol (IP) header-enhanced messages. In embodiments of the present invention, the order of user plane functions in the core network user plane forwarding path can be determined based on the order in which they receive messages, i.e., the order in which messages arrive at the user plane functions. For example, the first user plane function in the core network user plane forwarding path to receive a message, i.e., the first user plane function that a message arrives at in the core network user plane forwarding path, can be referred to as the first user plane function in the core network user plane forwarding path. The last user plane function in the core network user plane forwarding path to receive a message, i.e., the last user plane function that a message arrives at in the core network user plane forwarding path, can be referred to as the last user plane function in the core network user plane forwarding path. Other user plane functions in the core network user plane forwarding path can be referred to as intermediate user plane functions. It should be understood that if the core network user plane forwarding path includes only two user plane functions, no intermediate user plane functions exist in the core network user plane forwarding path.

[0057] In actual applications, the core network user plane forwarding path can be: an uplink core network user plane forwarding path, used to complete the transmission of uplink data packets; or a downlink core network user plane forwarding path, used to complete the transmission of downlink data packets, as described below:

[0058] For the uplink core network user plane forwarding path, the first UPF where the message arrives in the core network user plane forwarding path can communicate with the RAN to receive the GTP-U message sent by the RAN. The uplink GTP-U message sent by the RAN is generated based on the uplink data packet sent by the terminal. After receiving the GTP-U message, it can generate an IP header enhancement message based on the GTP-U message and send the IP header enhancement message. The intermediate UPF can be used to generate a new IP header enhancement message based on the received IP header enhancement message and send the new IP header enhancement message. The last UPF can communicate with the DN to generate an IP message based on the received IP header enhancement message and send the IP message to the DN to complete the transmission of the uplink data packet.

[0059] For the downlink core network user plane forwarding path, the first UPF where the message arrives in the core network user plane forwarding path can communicate with the DN to receive the IP message sent by the DN. After receiving the IP message, it can generate an IP header enhancement message based on the IP message and send the IP header enhancement message. The intermediate UPF can be used to generate a new IP header enhancement message based on the received IP header enhancement message and send the new IP header enhancement message. The last UPF can communicate with the RAN to generate a GTP-U message based on the received IP header enhancement message and send the GTP-U message to the RAN. The RAN then sends a downlink data packet to the terminal based on the GTP-U message, completing the transmission of the downlink data packet.

[0060] The SMF can be used to determine the core network user plane forwarding path, IP header enhancement message construction rules, and GTP-U message construction rules. The SMF can, but is not limited to, communicate with the first and last UPFs where messages arrive in the core network user plane forwarding path. It is used to send IP header enhancement message construction rules to the first UPF and send GTP-U message construction rules to the last UPF in the downstream core network user plane forwarding path.

[0061] In this embodiment of the present invention, the SMF may also be referred to as a control plane function. An IP header-enhanced message may also be referred to as a segment routing (SR) message. A terminal may also be referred to as user equipment (UE). Communication between the UPF and the RAN can be understood as communication between the UPF and network devices in the RAN; communication between the UPF and the DN can be understood as communication between the UPF and network devices in the DN.

[0062] In the fifth generation (5 th In the 5G (5th Generation) communication standard, the user plane function may be referred to as the UPF. In other communication standards, the user plane function may be referred to as other terms, depending on the communication protocol and not limited in the embodiments of the present invention. For ease of description, the user plane function will be referred to as the UPF for illustrative purposes, but this does not limit the terminology of the user plane function. The UPF may also be referred to as a UPF module, data plane processing node, SR node, UPF functional unit, or UPF node.

[0063] UPF may include but is not limited to at least one of the following functions:

[0064] Packet filter function is used to assign different messages to corresponding flows and mark them with the Quality of Service Flow ID (QFI) value;

[0065] Quality of Service (QoS) control module, used to process service flows of different QFIs and perform different QoS controls;

[0066] Protocol Data Unit Session Anchor (PSA) UPF, used for billing and layer indication (LI);

[0067] Network Address Translation (NAT) function;

[0068] Deep Packet Inspection (DPI) functionality;

[0069] Domain Name System (DNS) resolver functionality.

[0070] The message transmission method according to an embodiment of the present invention is described below.

[0071] See also Figure 2 , Figure 2 This is one of the flow charts of the message transmission method provided by an embodiment of the present invention. Figure 2 The message transmission method shown is executed by a first user plane function, which is the first user plane function at which the message arrives in the core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2.

[0072] like Figure 2 As shown, the message transmission method executed by the first UPF where the message arrives in the core network user plane forwarding path may include the following steps:

[0073] Step 201: Receive IP header enhancement message construction rules sent by the session management function SMF.

[0074] In specific implementation, SMF can send the IP header enhanced message construction rules to the first user plane function during the session establishment process, or it can send the IP header enhanced message construction rules to the first user plane function based on the request for the first user plane function. The specific decision can be made based on actual conditions, and the embodiment of the present invention does not limit this.

[0075] Step 202: Generate a first IP header enhancement message according to the IP header enhancement message construction rule, where the first IP header enhancement message includes addresses of all other user plane functions among the N user plane functions except the first user plane function.

[0076] In specific implementation, the IP header enhanced message construction rule may include the core network user plane forwarding path, and may be used to instruct the first user plane function to include the addresses of all user plane functions among the N user plane functions located after the first user plane function in the segment address list (Segment List) of the IP header enhanced message when generating the IP header enhanced message.

[0077] Furthermore, the IP header enhanced message construction rule can be used to indicate that the user plane function addresses in the segment address list are sorted in the order in which the user plane functions receive the messages, such as: the address of the second user plane function in the core network user plane forwarding path can be the first user plane function address in the segment address list, or the last user plane function address.

[0078] In this way, after obtaining the IP header enhancement message construction rule, the first user plane function can generate a first IP header enhancement message according to the IP header enhancement message construction rule, and the first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function.

[0079] For easier understanding, the following examples are provided:

[0080] Assume that the core network user plane forwarding path included in the IP header enhanced message construction rule is user plane function 1→user plane function 2→user plane function 3, that is, user plane function 1 is the first user plane function that the message arrives at in the core network user plane forwarding path, user plane function 2 is the second user plane function that the message arrives at in the core network user plane forwarding path, and user plane function 3 is the last user plane function that the message arrives at in the core network user plane forwarding path.

[0081] Then, the IP header enhanced message generated by the first user plane function based on the IP header enhanced message construction rule may include: the address of user plane function 2 and the address of user plane function 3.

[0082] Step 203: Send the first IP header enhanced message.

[0083] In specific implementation, the first user plane function can send the first IP header enhancement message to the second user plane function in the core network user plane forwarding path, or it can send the first IP header enhancement message to all other user plane functions among the N user plane functions except the first user plane function. The specific decision can be made based on actual conditions, and the embodiment of the present invention does not limit this.

[0084] In an embodiment of the present invention, after the second user plane function where the message arrives in the core network user plane forwarding path receives the first IP header enhanced message, it can determine whether it is the last user plane function in the core network user plane forwarding path based on the user plane function address included in the first IP header enhanced message.

[0085] If so, the second user plane function in the core network user plane forwarding path can generate an IP message based on the first IP header enhancement message and send the IP message to the DN when the core network user plane forwarding path is an uplink core network user plane forwarding path; and can generate a GTP-U message based on the first IP header enhancement message and send the GTP-U message to the RAN when the core network user plane forwarding path is a downlink core network user plane forwarding path.

[0086] If not, the second user plane function in the core network user plane forwarding path can generate a new IP header enhancement message based on the first IP header enhancement message, and send the new IP header enhancement message to the next user plane function, and so on, until the transmission of the uplink data packet or the downlink data packet is completed.

[0087] In this embodiment of the present invention, after determining the core network user plane forwarding path, the SMF sends an IP header enhancement message construction rule determined based on the core network user plane forwarding path to the first user plane function in the core network user plane forwarding path where the packet arrives. This first user plane function can then generate a first IP header enhancement message, which includes the addresses of all other user plane functions among the N user plane functions except the first one, and pass the generated IP header enhancement message to the next user plane function. After receiving the IP header enhancement message, the next user plane function can determine whether it is the last user plane function in the core network user plane forwarding path. If not, it can generate a new IP header enhancement message based on the received IP header enhancement message and pass the generated IP header enhancement message to the next user plane function. If so, it can reconstruct the IP header enhancement message into a target message and send it to the target network. This embodiment of the present invention breaks the hop-by-hop tunneling mechanism. Each user plane function in the core network user plane forwarding path can determine the next recipient of a message based on the received IP header enhancement message, thereby reducing the complexity of message transmission. In addition, the interaction between the user plane function and the SMF in the core network user plane forwarding path can be reduced, thereby reducing signaling overhead.

[0088] In an embodiment of the present invention, the IP header enhanced message construction rule may also be used to indicate:

[0089] The source address (SA) in the IP header of the IP header enhanced message is set to the address of the first user plane function that the message arrives at in the core network user plane forwarding path, and the destination address (DA) is set to the address of the last user plane function that the message arrives at in the core network user plane forwarding path;

[0090] In the segment address list of the IP header enhanced message, at least the address of the last user plane function that the message arrives at in the core network user plane forwarding path is filled with the tunnel endpoint identification (TEID) of the service chain corresponding to the core network user plane forwarding path.

[0091] In a specific implementation, in a first implementation, the TEID may be filled only in the address of the last user plane function in the core network user plane forwarding path included in the segment address list. In a second implementation, the TEID may be filled in each address included in the segment address list. Furthermore, the IP header enhanced message construction rule may also be used to indicate:

[0092] The source address and / or destination address of the IP header enhanced message is filled with the TEID corresponding to the core network user plane forwarding path.

[0093] In practical applications, the TEID may be filled in the last 64 bits of the address, but is not limited thereto.

[0094] As can be seen from the above content, for the uplink core network user plane forwarding path, the first user plane function interacts with the RAN; while for the downlink core network user plane forwarding path, the first user plane function interacts with the DN. Because the networks interacted by the first user plane functions of the uplink core network user plane forwarding path and the downlink core network user plane forwarding path are different, the actions performed by the first user plane functions of the uplink core network user plane forwarding path and the downlink core network user plane forwarding path may be different. The specific explanation is as follows:

[0095] 1. For the uplink core network user plane forwarding path.

[0096] Optionally, generating a first IP header enhanced message according to the IP header enhanced message construction rule includes:

[0097] receiving a General Packet Radio Service Tunneling Protocol-User Plane GTP-U message sent by a radio access network RAN;

[0098] Performing a first operation according to the IP header enhanced message construction rule and the GTP-U message to obtain a first IP header enhanced message, the first operation including:

[0099] Generate an IP header enhanced message header, where the IP header enhanced message header includes a source address, a destination address, and a segment address list, where the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, and the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function;

[0100] The GTP-U layer in the GTP-U message is deleted.

[0101] In this optional embodiment, the first user plane function interacts with the RAN and receives the GTP-U message sent by the RAN. Therefore, the first IP header enhanced message in this optional embodiment can be obtained according to the IP header enhanced message construction rule and the GTP-U message.

[0102] The first IP header enhanced message may include:

[0103] An IP header enhancement header, where the IP header enhancement header includes an SA, a DA, and a segment address list, where the SA is the address of the first user plane function, the DA is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, and the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function;

[0104] The payload, also called the Protocol Data Unit (PDU), is an uplink data packet sent by the terminal.

[0105] For easier understanding, the following examples are provided:

[0106] Assume that the IP header enhanced message construction rule includes the uplink core network user plane forwarding path as user plane function 1 → user plane function 2 → user plane function 3, that is, user plane function 1 is the first user plane function that the message arrives at in the uplink core network user plane forwarding path, user plane function 2 is the second user plane function that the message arrives at in the uplink core network user plane forwarding path, and user plane function 3 is the last user plane function that the message arrives at in the uplink core network user plane forwarding path.

[0107] Then, the first IP header enhanced message may include:

[0108] IP header enhancement header, the IP header enhancement header includes SA for the address of user plane function 1, DA for the address of user plane function 3, and the segment address list including the address of user plane function 2 and the address of user plane function 3;

[0109] Payload.

[0110] In this way, after receiving the first IP header enhanced message, the next user plane function of the first user plane function can directly determine whether it is the last user plane function in the core network user plane forwarding path based on the IP header, thereby improving the determination rate. In addition, the tunnel corresponding to the service chain can be determined and the message can be transmitted using the tunnel mechanism, thereby improving the reliability of message transmission.

[0111] 2. For the downlink core network user plane forwarding path.

[0112] Optionally, generating a first IP header enhanced message according to the IP header enhanced message construction rule includes:

[0113] Receive IP packets sent by the data network;

[0114] Determine the tunnel endpoint identifier TEID corresponding to the IP packet;

[0115] Performing a second operation according to the IP header enhanced message construction rule and the IP message to obtain a first IP header enhanced message, the second operation including:

[0116] Generate an IP header enhanced message header, the IP header enhanced message header including a source address, a destination address and a segment address list, the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, the segment address list includes the addresses of all other user plane functions of the N user plane functions except the first user plane function, and at least the address of the last user plane function arrived at by the message in the core network user plane forwarding path in the segment address list is filled with the TEID.

[0117] In this optional embodiment, the first user plane function interacts with the DN to receive the IP message sent by the DN and the second TEID corresponding to the IP message. Therefore, the first IP header enhanced message in this optional embodiment can be obtained according to the IP header enhanced message construction rule and the IP message.

[0118] The first IP header enhanced message may include:

[0119] An IP header enhanced message header, the IP header enhanced message header including an SA, a DA, and a segment address list, where the SA is the address of the first user plane function, the DA is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function, and at least the address of the last user plane function arrived at by the message in the core network user plane forwarding path in the segment address list is filled with the TEID;

[0120] Payload: The downlink data packet sent by DN.

[0121] For easier understanding, the following examples are provided:

[0122] Assume that the IP header enhanced message construction rule includes the downlink core network user plane forwarding path of user plane function 3 → user plane function 2 → user plane function 1, that is, user plane function 3 is the first user plane function that the message arrives at in the uplink core network user plane forwarding path, user plane function 2 is the second user plane function that the message arrives at in the uplink core network user plane forwarding path, and user plane function 1 is the last user plane function that the message arrives at in the uplink core network user plane forwarding path.

[0123] Then, the first SR may include:

[0124] IP header enhancement header, where the IP header enhancement header includes: SA, which is the address of user plane function 3; DA, which is the address of user plane function 1; and a segment address list, which includes the address of user plane function 2 and the address of user plane function 1. Optionally, the address of user plane function 1 in the segment address list is filled with TEID.

[0125] Payload.

[0126] In this way, on the one hand, after receiving the first IP header enhanced message, the next user plane function of the first user plane function can directly determine whether it is the last user plane function in the core network user plane forwarding path based on the IP header, thereby improving the determination rate. On the other hand, the TEID filled in the segment address list can help the RAN determine the tunnel corresponding to the service chain and use the tunnel mechanism to transmit the message, thereby improving the reliability of message transmission. In addition, the tunnel corresponding to the service chain can be determined and the tunnel mechanism can be used to transmit the message, thereby improving the reliability of message transmission.

[0127] See also Figure 3 , Figure 3 This is the second flowchart of the message transmission method provided by an embodiment of the present invention. Figure 2The message transmission method shown is performed by a second user plane function, where the second user plane function is the i-th user plane function in the core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2, and i is an integer greater than 1 and less than N. It can be understood that the second user plane function is any intermediate user plane function in the core network user plane forwarding path.

[0128] like Figure 3 As shown, the message transmission method performed by the intermediate user plane function in the core network user plane forwarding path may include the following steps:

[0129] Step 301: Receive a second IP header enhanced message sent by the i-1th user plane function in the core network user plane forwarding path, and the segmented address list of the second IP header enhanced message includes the addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path.

[0130] It can be understood that, when the second user plane function is the first intermediate user plane function in the core network user plane forwarding path, that is, the second user plane function at which the message arrives in the core network user plane forwarding path, the i-1th user plane function is the first user plane function at which the message arrives in the core network user plane forwarding path, that is, Figure 2 The first user plane function in the method embodiment. In this case, the second IP header enhanced message is Figure 2 The first IP header enhancement message in the method embodiment, that is, the i-1th user plane function can be used Figure 2 The method embodiment generates an IP header enhanced message.

[0131] In the case where the second user plane function is another intermediate user plane function in the core network user plane forwarding path, the i-1th user plane function is also an intermediate user plane function in the core network user plane forwarding path. In this case, the i-1th user plane function can be Figure 3 The method embodiment generates an IP header enhanced message.

[0132] For easier understanding, the following examples are provided:

[0133] Assume that the core network user plane forwarding path included in the IP header enhanced message construction rule is user plane function 1 → user plane function 2 → user plane function 4 → user plane function 3, that is, user plane function 1 is the first user plane function that the message arrives at in the core network user plane forwarding path, user plane function 2 is the second user plane function that the message arrives at in the core network user plane forwarding path, user plane function 4 is the third user plane function that the message arrives at in the core network user plane forwarding path, and user plane function 4 is the last user plane function that the message arrives at in the core network user plane forwarding path.

[0134] Assuming that the second user plane function is user plane function 4, the (i-1)th user plane function is user plane function 2. In this case, the segment address list of the second IP header enhanced message includes: the address of user plane function 4 and the address of user plane function 3.

[0135] Step 302: Generate a third IP header enhancement message based on the second IP header enhancement message, wherein the segment address list of the third IP header enhancement message includes the addresses of all subsequent user plane functions in the core network user plane forwarding path located after the i-th user plane function.

[0136] In a specific implementation, the address of the second user plane function can be obtained by deleting the address of the second user plane function from the segment address list of the second IP header enhanced message. For example, in the above example, the segment address list of the second IP header enhanced message includes the address of user plane function 4 and the address of user plane function 3. Then, the segment address list of the third IP header enhanced message includes the address of user plane function 3.

[0137] Step 303: Send the third IP header enhanced message.

[0138] In specific implementation, the third IP header enhanced message can be sent to the i+1th user plane function in the core network user plane forwarding path, or the third IP header enhanced message can be sent to all other user plane functions in the core network user plane forwarding path. The specific decision can be made based on actual conditions, and the embodiment of the present invention does not limit this.

[0139] In an embodiment of the present invention, after the i+1th user plane function in the core network user plane forwarding path receives the third IP header enhancement message, it can determine whether it is the last user plane function in the core network user plane forwarding path based on the segmented address list included in the third IP header enhancement message.

[0140] If so, the i+1th user plane function in the core network user plane forwarding path can generate an IP message based on the third IP header enhancement message and send the IP message to the DN when the core network user plane forwarding path is an uplink core network user plane forwarding path; and can generate a GTP-U message based on the third IP header enhancement message and send the GTP-U message to the RAN when the core network user plane forwarding path is a downlink core network user plane forwarding path.

[0141] If not, the i+1th user plane function in the core network user plane forwarding path can obtain a new IP header enhancement message based on the third IP header enhancement message, and send the new IP header enhancement message to the next user plane function, and so on, until the transmission of the uplink data packet or the downlink data packet is completed.

[0142] In an embodiment of the present invention, after receiving an IP header enhancement message, the intermediate user plane function in the core network user plane forwarding path can determine whether it is the last user plane function in the core network user plane forwarding path based on the segment address list in the IP header enhancement message. If not, a new IP header enhancement message can be generated based on the received IP header enhancement message, and the generated new IP header enhancement message can be sent. If so, a target message can be generated based on the IP header enhancement message and sent to the target network. It can be seen that the embodiment of the present invention breaks the hop-by-hop tunnel mechanism. The intermediate user plane functions in the core network user plane forwarding path can all identify the next recipient of the message based on the obtained IP header enhancement message without interacting with the SMF, thereby reducing the complexity of message transmission and reducing signaling overhead.

[0143] Optionally, the second IP header enhanced message and the third IP header enhanced message satisfy: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function that the message arrives at in the user plane function forwarding path, and the destination address is the address of the last user plane function that the message arrives at in the user plane function forwarding path.

[0144] Furthermore, at least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

[0145] In this optional embodiment, the IP header enhancement message received by the intermediate user plane function in the core network user plane forwarding path, as well as the generated IP header enhancement message, both satisfy the following conditions: the SA in the IP header enhancement message header is the address of the first user plane function that the message arrives at in the core network user plane forwarding path, and the DA is the address of the last user plane function that the message arrives at in the core network user plane forwarding path. In this way, after receiving the IP header enhancement message, each user plane function in the core network user plane forwarding path, except for the first user plane function, can directly determine whether it is the last user plane function in the core network user plane forwarding path based on the IP header, thereby improving the determination rate.

[0146] In addition, the TEID can be filled in at least the address of the last user plane function of the core network user plane forwarding path included in the segment list. In this way, the tunnel corresponding to the service chain can be determined and the message can be transmitted using the tunnel mechanism, thereby improving the reliability of message transmission.

[0147] See also Figure 4 , Figure 4 This is the third flowchart of the message transmission method provided by an embodiment of the present invention. Figure 4 The message transmission method shown is executed by a third user plane function, where the third user plane function is the last user plane function in a core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2.

[0148] like Figure 4 As shown, the message transmission method performed by the last user plane function in the core network user plane forwarding path may include the following steps:

[0149] Step 401: Receive the fourth IP header enhanced message sent by the N-1th user plane function in the core network user plane forwarding path, and the segmented address list of the fourth IP header enhanced message includes the addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path.

[0150] It can be understood that when N is equal to 2, the N-1th UDF is the first user plane function that the message arrives at in the core network user plane forwarding path, that is, Figure 2 The first user plane function in the method embodiment. In this case, the fourth IP header enhanced message is Figure 2 The first IP header enhancement message in the method embodiment, that is, the N-1th user plane function can be used Figure 2 The method embodiment generates an IP header enhanced message.

[0151] When N is greater than 2, the N-1th user plane function is an intermediate user plane function in the core network user plane forwarding path. In this case, the N-1th user plane function can be Figure 3 The method embodiment generates an IP header enhanced message.

[0152] Step 402 generates a target message according to the fourth IP header enhanced message.

[0153] In specific implementation, the target message may be an IP message or a GTP-U message, which may be determined according to the form of expression of the core network user plane forwarding path.

[0154] When the core network user plane forwarding path is an uplink core network user plane forwarding path, the target message is an IP message; when the core network user plane forwarding path is a downlink core network user plane forwarding path, the target message is a GTP-U message.

[0155] Step 403: Send the target message to the target network.

[0156] In a specific implementation, the target network may be a DN or a RAN, which may be determined based on the representation of the core network user plane forwarding path. Specifically, if the target packet is an IP packet, the target network is the DN; if the target packet is a GTP-U packet, the target network is the RAN.

[0157] In this embodiment of the present invention, after receiving the IP header enhancement message, the last user plane function can reconstruct the IP header enhancement message into a target message and send it to the target network. This embodiment of the present invention breaks the hop-by-hop tunneling mechanism, thereby reducing the complexity of message transmission and signaling overhead.

[0158] Optionally, the fourth IP header enhanced message satisfies:

[0159] The fourth IP header enhanced message meets the following requirements: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function that the message arrives at in the core network user plane forwarding path, and the destination address is the address of the last user plane function in the core network user plane forwarding path.

[0160] Furthermore, at least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

[0161] In this optional embodiment, the IP header-enhanced message received by the third user plane function satisfies the following requirements: the SA in the IP header-enhanced message header is the address of the first user plane function that the message reaches in the core network user plane forwarding path, and the DA is the address of the last user plane function in the core network user plane forwarding path. In this way, after receiving the IP header-enhanced message, each user plane function in the core network user plane forwarding path, except for the first user plane function, can directly determine whether it is the last user plane function in the core network user plane forwarding path based on the IP header, thereby improving the determination rate.

[0162] In addition, the TEID can be filled in at least the address of the last user plane function of the core network user plane forwarding path included in the segment list. In this way, the tunnel corresponding to the service chain can be determined and the message can be transmitted using the tunnel mechanism, thereby improving the reliability of message transmission.

[0163] As can be seen from the above content, for the uplink core network user plane forwarding path, the last user plane function interacts with the DN; while for the downlink core network user plane forwarding path, the last user plane function interacts with the RAN. Because the networks interacted by the last user plane function of the uplink core network user plane forwarding path and the downlink core network user plane forwarding path are different, the actions performed by the last user plane function of the uplink core network user plane forwarding path and the downlink core network user plane forwarding path may be different. The specific explanation is as follows:

[0164] 1. For the uplink core network user plane forwarding path.

[0165] The third user plane function may convert the received IP header-enhanced message into a pure IP message and send the IP message to the DN. In a specific implementation, the IP header enhancement header in the received IP header-enhanced message may be deleted, and the IP message may include only the payload. Of course, in other implementations, the IP message may include other information in addition to the payload, which may be determined based on actual needs and is not limited in this embodiment of the present invention.

[0166] 2. For the downlink core network user plane forwarding path.

[0167] Optionally, the generating a target message according to the fourth IP header enhanced message includes:

[0168] Receive GTP-U message construction rules sent by SMF;

[0169] Performing a third operation according to the GTP-U message construction rule and the fourth IP header enhanced message to obtain a target message, the third operation including:

[0170] Generate a GTP-U message header, where the GTP-U message header includes a source address and a destination address, where the source address is the address of the third user plane function, and the destination address is the address of the RAN;

[0171] Adding a GTP-U layer, the GTP-U layer including a TEID extracted from an address of an enhanced IP header of the fourth enhanced IP header message;

[0172] Delete the IP header enhanced message header.

[0173] In specific implementation, SMF can send the IP header enhanced message construction rules to the third user plane function during the session establishment process, or it can send the IP header enhanced message construction rules to the third user plane function based on a request for the third user plane function. The specific details can be determined according to actual conditions, and the embodiments of the present invention do not limit this.

[0174] In an embodiment of the present invention, the GTP-U message construction rule may be used to indicate:

[0175] Set the SA in the GTP-U message header to the address of the last UDF in the core network user plane forwarding path, and set the DA to the address of the RAN;

[0176] The TEID is carried in the GTP-U layer.

[0177] In this way, after receiving the GTP-U message construction rule, the third user plane function can obtain the GTP-U message according to the GTP-U message construction rule and the fourth IP header enhanced message.

[0178] A GTP-U message may include:

[0179] GTP-U message header. The SA included in the GTP-U message header is the address of the last UDF in the core network user plane forwarding path, and the DA is the address of the RAN;

[0180] GTP-U layer, the GTP-U layer includes TEID;

[0181] Payload: The downlink data packet sent by DN.

[0182] For easier understanding, the following examples are provided:

[0183] Assume that the IP header enhanced message construction rule includes the downlink core network user plane forwarding path of user plane function 3 → user plane function 2 → user plane function 1, that is, user plane function 3 is the first user plane function that the message arrives at in the uplink core network user plane forwarding path, user plane function 2 is the second user plane function that the message arrives at in the uplink core network user plane forwarding path, and user plane function 1 is the last user plane function that the message arrives at in the uplink core network user plane forwarding path.

[0184] Then, the GTP-U message may include:

[0185] GTP-U message header, where SA included in the GTP-U message header is the address of user plane function 1, and DA is the address of RAN;

[0186] GTP-U layer, the GTP-U layer includes TEID;

[0187] Payload.

[0188] See also Figure 5 , Figure 5 This is the fourth flowchart of the message transmission method provided by an embodiment of the present invention. Figure 5 The message transmission method shown is performed by SMF.

[0189] like Figure 5 As shown, the message transmission method performed by the SMF may include the following steps:

[0190] Step 501: Determine the core network user plane forwarding path related to the first terminal based on at least one of the terminal's location information, network policy, network slice identifier, and data network name, where the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2.

[0191] In specific implementations, the SMF may obtain the above information in different ways. For example, the terminal's network slice identifier and data network name (DNN) may be sent by the terminal. Furthermore, the network slice identifier and DNN may be carried in the session establishment request sent by the terminal. The terminal's location information may be provided by the Access and Mobility Management Function (AMF) or the terminal. The network policy may be provided by the Policy Control Function (PCF).

[0192] The terminal's network slice identifier and data network name DNN can be used to determine the user plane function that interacts with DN in the core network user plane forwarding path, that is, the last user plane function in the uplink core network user plane forwarding path, or the first user plane function where the message arrives in the downlink core network user plane forwarding path.

[0193] The terminal's location information can be used to determine the user plane function that interacts with the RAN in the core network user plane forwarding path, that is, the first user plane function that the message arrives at in the uplink core network user plane forwarding path, or the last user plane function in the downlink core network user plane forwarding path.

[0194] Network policies can be used to determine intermediate user plane functions in the core network user plane forwarding path.

[0195] In practical applications, the network slice identifier can be expressed as single network slice selection assistance information (S-NSSAI); the network policy can be expressed as policy and charging control (PCC) policy, but is not limited to this.

[0196] Step 502: Send an IP header enhancement message construction rule to the first user plane function, where the IP header enhancement message construction rule is used to generate a first IP header enhancement message. The first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function. The first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

[0197] It should be noted that the related description of the IP header enhanced message construction rules and the first IP header enhanced message can be found in the above description and will not be repeated here.

[0198] Optionally, when the core network user plane forwarding path is a downlink core network user plane forwarding path, the method further includes:

[0199] Send a GTP-U message construction rule to a third user plane function, where the GTP-U message construction rule is used to generate a GTP-U message. The third user plane function is the last user plane function in the core network user plane forwarding path.

[0200] It should be noted that the GTP-U message construction rules and the related description of the GTP-U message can be found in the above description and will not be repeated here.

[0201] Optionally, the target user plane function in the core network user plane forwarding path is a user plane function closest to the first terminal;

[0202] Wherein, when the core network user plane forwarding path is an uplink core network user plane forwarding path, the target user plane function is the first user plane function in the core network user plane forwarding path;

[0203] In a case where the core network user plane forwarding path is a downlink core network user plane forwarding path, the target user plane function is the last user plane function in the core network user plane forwarding path.

[0204] In this optional implementation, the user plane function closest to the terminal can be determined as the user plane function interacting with the RAN in the core network user plane forwarding path. In this way, the message transmission path can be shortened and the message transmission efficiency can be improved.

[0205] Optionally, the network policy is generated by the policy control function based on at least one of the following: an application identifier sent by the application function; and a user plane processing requirement corresponding to the application identifier.

[0206] In a specific implementation, the application identification (Application Identification) may be provided by an application function (AF), but is not limited thereto.

[0207] Furthermore, the user plane processing requirements include: whether the message is required to be processed by a target function, and the target function includes at least one of the following: network address translation NAT, domain name system DNS, quality of service QoS, deep packet inspection DPI.

[0208] It is understandable that the user plane processing requirements corresponding to different application identifiers may be the same or different. For application identifiers with different user plane processing requirements, the corresponding intermediate user plane functions of the core network user plane forwarding path may be different.

[0209] In an embodiment of the present invention, a terminal may support the IP header enhancement mechanism. In specific implementations, the SMF may determine whether the terminal supports the IP header enhancement mechanism based on the terminal's indication information or the terminal's contract information. In other words, the terminal may indicate that it supports the IP header enhancement mechanism; or, the terminal's contract information may explicitly indicate that it supports the IP header enhancement mechanism.

[0210] It should be noted that the various optional implementation methods introduced in the embodiments of the present application can be implemented in combination with each other or can be implemented separately, and the embodiments of the present application do not limit this.

[0211] For easier understanding, the following examples are provided:

[0212] It should be noted that in the following examples, the IP mechanism is represented by the sixth version of the IP (IPv6) mechanism; the IP header enhancement message mechanism is represented by the sixth version of the SR (SRv6) mechanism; the user plane function is represented by the UPF; and the IP header enhancement message is represented by the SR message. However, it should be understood that the embodiments of the present invention are not limited to the specific versions of the IP mechanism and the IP header enhancement message mechanism.

[0213] In this example, the forwarding mechanism of the mobile network can be redesigned based on the SRv6 mechanism of the general IP network. The core idea of ​​this example is to break the hop-by-hop tunneling mechanism. At the first UPF, the SMF is responsible for issuing the entire transmission path, that is, clearly defining the UPF address of each hop in the path.

[0214] 1. Functions of SMF:

[0215] 1) Path selection: Based on the S-NSSAI and DNN provided by the UE, the PSAUPF module that interacts with the DN is determined, i.e., the mobile network's egress to the Internet. Based on the UE's location, the UPF module that interacts with the RAN is selected.

[0216] 2) Formulate forwarding rules: Based on the PCC policy, the SMF identifies the forwarding path corresponding to the application identifier, formulates forwarding rules, and sends them to the first UPF module. The application identifier is also called a packet flow description (PFD).

[0217] 3) Sending forwarding rules: The SMF passes control signaling to the first selected UPF. This control signaling includes: for uplink and downlink data, sending a forwarding path list as shown in Table 1 to the first UPF, including SR header rules that indicate subsequent UPFs. For downlink data, sending rules for reconstructing GTP-U messages to the last UPF.

[0218] Table 1: Application identification and core network user plane forwarding path

[0219] Application Identification Core network user plane forwarding path Application 1 UPF1→UPF2→UPF3 Application 2 UPF1→UPF4→UPF3 …… ……

[0220] 2. UPF function:

[0221] 1) For uplink traffic, the first UPF node is responsible for removing the GTP-U tunnel and constructing an SRv6 message. This SRv6 message contains: the message's destination address (the address of the last UPF node), the message's source address (the address of the first UPF node), the SRv6 header's length (SL), and a series of subsequent destination address information in the SRv6 header. The last 64 bits of this destination address and the subsequent destination address information in the SRv6 header are used to fill in the TEID value of the N3 tunnel, which identifies the tunnel to which the service chain belongs. The last UPF node is responsible for removing the SRv6 header and IP header, converting the message into a pure IPv6 message.

[0222] 2) For downlink traffic, the first UPF node is responsible for constructing the SRv6 message, with the same content as above. The last UPF node is responsible for recovering the GTP-U message for interworking with the RAN, that is, extracting the TEID information in the message destination address and constructing the GTP-U message.

[0223] 3) UPF data plane processing node functions may include but are not limited to: Packet filter function - assigning different messages to corresponding flows and marking them with QFI values; QoS control module - processing service flows with different QFIs and performing different QoS controls; PSAUPF - billing and LI; NAT function; DPI function; DNS resolver function;

[0224] Third, the selection of the forwarding path needs to consider the PCF's data processing policy. That is, the PCF combines the third-party service information (such as application ID) or subscription information provided by the AF, the UE's subscription information, and other information to determine the forwarding processing rules, and then passes the PCC policy (PCC rule) to the SMF.

[0225] 4. Service Chain Architecture: The SMF determines the UPF functional units that the service needs to pass through and forms the corresponding service chain. In the UPF units that the message passes through, the corresponding SRv6 message header addition and modification operations are performed in accordance with SRv6 technical requirements.

[0226] For ease of understanding, combined Figure 6 The instructions are as follows:

[0227] Figure 6The uplink core network user plane forwarding path in the example is UPF1→UPF2→UPF3. The RAN sends a GTP-U message to UPF1. The SA of the SRv6 message generated by UPF1 is UPF1's address, and the DA is UPF3's address; SL=2, and the segment address list includes the addresses of UPF3 and UPF2, respectively; Payload. UPF1 sends the SRv6 message it generates to UPF2. UPF2 modifies the SRv6 message it receives from UPF1. The SA of the modified SRv6 message is UPF1's address, and the DA is UPF3's address; SL=1, and the segment address list includes UPF3's address; Payload. UPF2 sends the SRv6 message it generates to UPF3. After receiving the SRv6 message from UPF1, UPF3 can extract only the Payload from the SRv6 message and send it to the DN.

[0228] In addition, RAN can interact with the Access and Mobility Management Function (AMF), and UPF can interact with SMF.

[0229] 5. Session establishment process

[0230] For ease of understanding, combined Figure 7 The instructions are as follows:

[0231] Step 1: AF pre-configures the service processing policy to PCF.

[0232] The service processing policy can include the application ID and the corresponding user plane processing requirements, such as whether data packets are required to be processed by functions such as NAT, DNS, QoS, and DPI. After receiving the requirements, the PCF formulates the corresponding policy control rules, namely the PCC policy.

[0233] Step 2: The UE initiates a session establishment request.

[0234] The session establishment request can carry the slice ID and DNN information. In addition, the UE can indicate that it supports SRv6 transmission, or the SMF can specify in the UE contract that the UE supports SRv6 mechanism transmission.

[0235] Step 3: SMF obtains the PCC policy related to the UE from PCF.

[0236] Step 4: SMF selects the UPF functional unit that supports the SRv6 mechanism and generates corresponding uplink and downlink forwarding rules.

[0237] For uplink forwarding, SMF determines the last UPF functional unit based on S-NSSAI and DNN, and determines the first UPF functional unit based on the UE location; downlink forwarding is consistent with the uplink path.

[0238] Step 5: SMF sends the corresponding uplink and downlink forwarding rules to the UPF function.

[0239] For uplink forwarding, the SMF sends the message reconstruction rules and SRv6 service chain forwarding rules to the first UPF functional unit. The message reconstruction rules include: extracting the TEID value in the GTP-U tunnel and deleting the GTP-U layer. The SRv6 service chain forwarding rules include: the destination address of the IPv6 message is the address of the last UPF functional unit, and the segmentlist of the SRv6 header is filled with a series of UPF functional unit addresses that the service chain passes through; the destination address of the message and the last 64 bits of the address in the SRv6 segment list are modified to the TEID value, which is used by the UPF functional unit to identify the tunnel to which it belongs. The tunnel mechanism is still used for service flow transmission, mainly to facilitate the correct transmission of downlink messages in a mobile state.

[0240] For downlink forwarding, the SMF sends SRv6 message construction rules to the first UPF functional unit, UPF2, including sending the TEID value of the N3 downlink tunnel to UPF2. The SMF sends message reconstruction rules to the last UPF functional unit, UPF1, to reconstruct the GTP-U message content.

[0241] Step 6: SMF sends a session establishment success response to the UE.

[0242] Step 7.1: The UE sends an uplink data packet to the RAN.

[0243] Step 7.2: RAN generates a GTP-U message based on the uplink data packet.

[0244] Step 7.3: RAN sends a GTP-U message to UPF function 1.

[0245] Step 7.4: UPF function 1 generates an SRv6 message based on the GTP-U message.

[0246] In specific implementation, when an uplink message reaches UPF1, UPF1 removes the GTP-U layer, extracts the TEID value, constructs the SRv6 message format, and fills the extracted TEID value into the last 64 bits of the SRv6 destination address and the last 64 bits of the SR segment list address. This SRv6 message represents the transmission path of the service chain corresponding to the service.

[0247] Step 8.1: UPF function 1 sends the generated SRv6 message to UPF function 2.

[0248] In step 8.2, UPF function 2 removes the SRv6 header and generates an IPv6 packet.

[0249] Step 8.3: UPF function 3 sends an IPv6 message to DN.

[0250] Step 9.1: DN sends an IPv6 packet.

[0251] Step 9.2: UPF function 2 generates an SRv6 message.

[0252] In specific implementation, UPF function 2 adds an SRv6 packet header and fills the TEID value of the N3 tunnel in the last 64 bits of the destination address and SRsegment list address.

[0253] Step 9.3: UPF function 2 sends an SRv6 message to UPF function 1.

[0254] Step 9.4: UPF function 1 reconstructs the SRv6 message to obtain a GTP-U message.

[0255] Step 9.5: UPF function 1 sends a GTP-U message to the RAN.

[0256] Step 9.6: RAN obtains the downlink data packet according to the GTP-U message.

[0257] Step 9.7: RAN sends a downlink data packet to the UE.

[0258] In the embodiment of the present invention, the mobile network is fully equipped with an SRv6 forwarding mechanism, which uses source address routing to flexibly build forwarding service chains, minimize the functional configuration of the UPF, reduce functional interaction with the SMF, and save signaling transmission. In addition, in the future, based on the SRv6 forwarding mechanism, the SMF can also be integrated with the transport layer Software Defined Network (SDN) controller to achieve seamless interoperability across domains and layers. In this way, the mobile network is no longer a layer of network built on the bearer network, but is integrated with the bearer network, simplifying the management and control mechanism.

[0259] See also Figure 8 , Figure 8 This is one of the structural diagrams of the user plane function provided in this embodiment. Figure 8The user plane function shown is a first user plane function, which is the first user plane function that a message arrives at in the core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2. The user plane function 800 may include:

[0260] The first transceiver 801 is configured to receive an Internet Protocol IP header enhancement message construction rule sent by a session management function SMF;

[0261] The first processor 802 is configured to generate a first enhanced IP header message according to the IP header enhanced message construction rule, where the first enhanced IP header message includes addresses of all other user plane functions among the N user plane functions except the first user plane function;

[0262] The first transceiver 801 is further configured to send the first IP header enhanced message.

[0263] Optionally, the first transceiver 801 is further configured to receive a General Packet Radio Service Tunneling Protocol-User Plane GTP-U message sent by a radio access network RAN;

[0264] The first processor 802 is configured to perform a first operation according to the IP header enhanced message construction rule and the GTP-U message to obtain a first IP header enhanced message, where the first operation includes:

[0265] Generate an IP header enhanced message header, where the IP header enhanced message header includes a source address, a destination address, and a segment address list, where the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, and the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function;

[0266] The GTP-U layer in the GTP-U message is deleted.

[0267] Optionally, the first transceiver 801 is further configured to receive IP packets sent from a data network;

[0268] The first processor 802 is configured to:

[0269] Determine the tunnel endpoint identifier TEID corresponding to the IP packet;

[0270] Performing a second operation according to the IP header enhanced message construction rule and the IP message to obtain a first IP header enhanced message, the second operation including:

[0271] Generate an IP header enhanced message header, wherein the IP header enhanced message header includes a source address, a destination address, and a segment address list, the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function, and at least the address of the last user plane function in the segment address list is filled with the TEID.

[0272] The user plane function 800 can implement the various processes that the first user plane function of the message arriving in the core network user plane forwarding path in the embodiment of the method of the present invention can implement, and achieve the same beneficial effects. To avoid repetition, it will not be repeated here.

[0273] See also Figure 9 , Figure 9 This is the second structural diagram of the user plane function provided by this embodiment. Figure 9 The user plane function shown is a second user plane function, which is the i-th user plane function at which the message arrives in the core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2 and i is an integer greater than 1 and less than N. The user plane function 900 may include:

[0274] The second transceiver 901 is configured to receive a second IP header enhanced message sent by the i-1th user plane function in the core network user plane forwarding path, where the segment address list of the second IP header enhanced message includes addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path;

[0275] The second processor 902 is configured to generate a third IP header enhanced message according to the second IP header enhanced message, where the segment address list of the third IP header enhanced message includes addresses of all subsequent user plane functions in the core network user plane forwarding path that are located after the i-th user plane function;

[0276] The second transceiver 901 is used to send the third IP header enhanced message.

[0277] Optionally, the second IP header enhanced message and the third IP header enhanced message satisfy: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function that the message arrives at in the user plane function forwarding path, and the destination address is the address of the last user plane function that the message arrives at in the user plane function forwarding path.

[0278] Optionally, at least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

[0279] The user plane function 900 can implement the various processes that the intermediate user plane function in the core network user plane forwarding path in the embodiment of the method of the present invention can implement, and achieve the same beneficial effects. To avoid repetition, it will not be repeated here.

[0280] See also Figure 10 , Figure 10 This is the third structural diagram of the user plane function provided by this embodiment. Figure 10 The user plane function shown is a third user plane function, which is the last user plane function that a message arrives at in the core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2. The user plane function 1000 may include:

[0281] The third transceiver 1001 is configured to receive a fourth IP header enhanced message sent by the N-1th user plane function in the core network user plane forwarding path, where the segment address list of the fourth IP header enhanced message includes addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path;

[0282] The third processor 1002 is configured to generate a target message according to the fourth IP header enhanced message;

[0283] The third transceiver 1001 is configured to send the target message to the target network;

[0284] Wherein, when the target message is an IP message, the target network is a data network; when the target message is a GTP-U message, the target network is a wireless access network.

[0285] Optionally, the fourth IP header enhanced message satisfies: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function where the message arrives in the core network user plane forwarding path, and the destination address is the address of the last user plane function in the core network user plane forwarding path.

[0286] Optionally, at least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

[0287] Optionally, when the target message is the GTP-U message, the third transceiver 1001 is configured to receive a GTP-U message construction rule sent by the SMF;

[0288] The third processor 1002 is configured to perform a third operation according to the GTP-U message construction rule and the fourth IP header enhanced message to obtain a target message, where the third operation includes:

[0289] Generate a GTP-U message header, where the GTP-U message header includes a source address and a destination address, where the source address is the address of the third user plane function, and the destination address is the address of the RAN;

[0290] Adding a GTP-U layer, the GTP-U layer including a TEID extracted from an address of an enhanced IP header of the fourth enhanced IP header message;

[0291] Delete the IP header enhanced message header.

[0292] The user plane function 1000 can implement the various processes that the last user plane function in the core network user plane forwarding path in the embodiment of the method of the present invention can implement, and achieve the same beneficial effects. To avoid repetition, it will not be repeated here.

[0293] See also Figure 11 , Figure 11 This is a structural diagram of the SMF provided in this embodiment. The SMF 1100 may include:

[0294] The fourth processor 1101 is configured to determine, based on at least one of the terminal's location information, a network policy, a network slice identifier, and a data network name, a core network user plane forwarding path related to the first terminal, where the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2.

[0295] The fourth transceiver 1102 is used to send an IP header enhancement message construction rule to the first user plane function, and the IP header enhancement message construction rule is used to generate a first IP header enhancement message. The first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function. The first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

[0296] Optionally, when the core network user plane forwarding path is a downlink core network user plane forwarding path, the fourth transceiver 1102 is further configured to:

[0297] Send a GTP-U message construction rule to a third user plane function, where the GTP-U message construction rule is used to generate a GTP-U message. The third user plane function is the last user plane function in the core network user plane forwarding path.

[0298] Optionally, the target user plane function in the core network user plane forwarding path is a user plane function closest to the first terminal;

[0299] Wherein, when the core network user plane forwarding path is an uplink core network user plane forwarding path, the target user plane function is the first user plane function in the core network user plane forwarding path;

[0300] In a case where the core network user plane forwarding path is a downlink core network user plane forwarding path, the target user plane function is the last user plane function in the core network user plane forwarding path.

[0301] Optionally, the network policy is generated by the policy control function based on at least one of the following: an application identifier sent by the application function; and a user plane processing requirement corresponding to the application identifier.

[0302] Optionally, the user plane processing requirement includes: whether the message is required to be processed by a target function, and the target function includes at least one of the following: network address translation NAT, domain name system DNS, quality of service QoS, and deep packet inspection DPI.

[0303] SMF1100 can implement each process that SMF in the embodiment of the method of the present invention can implement, and achieve the same beneficial effects. To avoid repetition, it will not be described here.

[0304] The embodiment of the present invention also provides a communication device. Figure 12 , the communication device may include a processor 1201, a memory 1202, and a program 12021 stored in the memory 1202 and executable on the processor 1201.

[0305] Among them, when the communication device is the first user plane function that the message arrives in the core network user plane forwarding path, the program 12021 can be implemented when the processor 1201 executes it. Figure 2 Any steps in the corresponding method embodiments and achieving the same beneficial effects will not be repeated here.

[0306] When the communication device is an intermediate user plane function where a message arrives in the core network user plane forwarding path, the program 12021 can be implemented when executed by the processor 1201. Figure 3 Any steps in the corresponding method embodiments and achieving the same beneficial effects will not be repeated here.

[0307] When the communication device is the last user plane function that a message arrives at in the core network user plane forwarding path, the program 12021 can be implemented when executed by the processor 1201. Figure 4 Any steps in the corresponding method embodiments and achieving the same beneficial effects will not be repeated here.

[0308] When the communication device is SMF, the program 12021 can be implemented when the processor 1201 executes Figure 5 Any steps in the corresponding method embodiments and achieving the same beneficial effects will not be repeated here.

[0309] A person skilled in the art will understand that all or part of the steps of the above-mentioned embodiment method can be completed by hardware related to program instructions, and the program can be stored in a readable medium. The embodiment of the present invention also provides a readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned Figure 2 、 Figure 3 、 Figure 4 or Figure 5 Any steps in the corresponding method embodiments can achieve the same technical effects and will not be described again here to avoid repetition.

[0310] The storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0311] The above is a preferred implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A message transmission method, characterized in that: The method is performed by a first user plane function, where the first user plane function is the first user plane function at which a message arrives in a core network user plane forwarding path, and the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; and the method includes: Receive an Internet Protocol IP header enhanced message construction rule sent by a session management function SMF; the IP header enhanced message construction rule is used to indicate that the user plane function addresses in the segment address list are sorted in the order in which the user plane functions receive the message, and the segment address list includes the addresses of all user plane functions in the N user plane functions that are located after the first user plane function; Generate a first IP header enhanced message according to the IP header enhanced message construction rule, where the first IP header enhanced message includes addresses of all other user plane functions among the N user plane functions except the first user plane function; Send the first IP header enhanced message.

2. The method according to claim 1, characterized in that Generating a first IP header enhanced message according to the IP header enhanced message construction rule includes: receiving a General Packet Radio Service Tunneling Protocol-User Plane GTP-U message sent by a radio access network RAN; Performing a first operation according to the IP header enhanced message construction rule and the GTP-U message to obtain a first IP header enhanced message, the first operation including: Generate an IP header enhanced message header, where the IP header enhanced message header includes a source address, a destination address, and a segment address list, where the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, and the segment address list includes the addresses of all other user plane functions in the N user plane functions except the first user plane function; The GTP-U layer in the GTP-U message is deleted.

3. The method according to claim 1, characterized in that Generating a first IP header enhanced message according to the IP header enhanced message construction rule includes: Receive IP packets sent by the data network; Determine the tunnel endpoint identifier TEID corresponding to the IP packet; Performing a second operation according to the IP header enhanced message construction rule and the IP message to obtain a first IP header enhanced message, the second operation including: Generate an IP header enhanced message header, the IP header enhanced message header including a source address, a destination address and a segment address list, the source address is the address of the first user plane function, the destination address is the address of the last user plane function arrived at by the message in the core network user plane forwarding path, the segment address list includes the addresses of all other user plane functions of the N user plane functions except the first user plane function, and at least the address of the last user plane function arrived at by the message in the core network user plane forwarding path in the segment address list is filled with the TEID.

4. A message transmission method, characterized in that: Executed by a second user plane function, the second user plane function is the i-th user plane function at which the message arrives in the core network user plane forwarding path, the core network user plane forwarding path includes N user plane functions, N is an integer not less than 2, and i is an integer greater than 1 and less than N; the method includes: Receive a second IP header enhanced message sent by an i-1th user plane function in the core network user plane forwarding path, where the segment address list of the second IP header enhanced message includes addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path; Determining, based on the segment address list in the second IP header enhanced message, whether it is the last user plane function in the core network user plane forwarding path, and if it is determined that the second user plane function is not the last user plane function, generating a third IP header enhanced message according to the second IP header enhanced message, where the segment address list of the third IP header enhanced message includes addresses of all subsequent user plane functions in the core network user plane forwarding path that are located after the i-th user plane function; Send the third IP header enhanced message.

5. The method according to claim 4, characterized in that The second IP header enhanced message and the third IP header enhanced message meet the following requirements: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function that the message arrives at in the user plane function forwarding path, and the destination address is the address of the last user plane function that the message arrives at in the user plane function forwarding path.

6. The method according to claim 5, characterized in that At least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

7. A message transmission method, characterized in that: Executed by a third user plane function, the third user plane function being the last user plane function at which the message arrives in the core network user plane forwarding path, the core network user plane forwarding path including N user plane functions, where N is an integer not less than 2; the method comprising: Receive a fourth IP header enhanced message sent by an N-1th user plane function in the core network user plane forwarding path, where the segment address list of the fourth IP header enhanced message includes addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path; Generating a target message according to the fourth IP header enhanced message; Sending the target message to the target network; Wherein, when the target message is an IP message, the target network is a data network; when the target message is a GTP-U message, the target network is a wireless access network.

8. The method according to claim 7, characterized in that The fourth IP header enhanced message meets the following requirements: the IP header enhanced message header includes a source address, a destination address and a segment address list, the source address is the address of the first user plane function that the message arrives at in the core network user plane forwarding path, and the destination address is the address of the last user plane function in the core network user plane forwarding path.

9. The method according to claim 8, characterized in that At least the address of the last user plane function in the segment address list is filled with the TEID corresponding to the IP packet.

10. The method according to claim 8, characterized in that When the target message is the GTP-U message, the generating the target message according to the fourth IP header enhanced message includes: Receive GTP-U message construction rules sent by SMF; Performing a third operation according to the GTP-U message construction rule and the fourth IP header enhanced message to obtain a target message, the third operation including: Generate a GTP-U message header, where the GTP-U message header includes a source address and a destination address, where the source address is the address of the third user plane function, and the destination address is the address of the RAN; Adding a GTP-U layer, the GTP-U layer including a TEID extracted from an address of an enhanced IP header of the fourth enhanced IP header message; Delete the IP header enhanced message header.

11. A message transmission method, characterized in that: Executed by SMF, the method includes: Determine, based on at least one of the terminal's location information, a network policy, a network slice identifier, and a data network name, a core network user plane forwarding path associated with the first terminal, where the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; Send an IP header enhancement message construction rule to the first user plane function, where the IP header enhancement message construction rule is used to generate a first IP header enhancement message. The first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function. The first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

12. The method according to claim 11, characterized in that In a case where the core network user plane forwarding path is a downlink core network user plane forwarding path, the method further includes: Send a GTP-U message construction rule to a third user plane function, where the GTP-U message construction rule is used to generate a GTP-U message. The third user plane function is the last user plane function in the core network user plane forwarding path.

13. The method according to claim 11, characterized in that The target user plane function in the core network user plane forwarding path is the user plane function closest to the first terminal; Wherein, when the core network user plane forwarding path is an uplink core network user plane forwarding path, the target user plane function is the first user plane function in the core network user plane forwarding path; In a case where the core network user plane forwarding path is a downlink core network user plane forwarding path, the target user plane function is the last user plane function in the core network user plane forwarding path.

14. The method according to claim 11, characterized in that The network policy is generated by the policy control function based on at least one of the following: an application identifier sent by the application function; and a user plane processing requirement corresponding to the application identifier.

15. The method according to claim 14, characterized in that The user plane processing requirement includes: whether the message is required to be processed by a target function, and the target function includes at least one of the following: network address translation NAT, domain name system DNS, quality of service QoS, and deep packet inspection DPI.

16. A user plane function, characterized in that The user plane function is a first user plane function, which is the first user plane function at which a message arrives in a core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2. The user plane function includes: A first transceiver is configured to receive an Internet Protocol (IP) header enhanced message construction rule sent by a session management function (SMF); the IP header enhanced message construction rule is configured to indicate that the user plane function addresses in the segment address list are sorted in the order in which the user plane functions receive the message, and the segment address list includes addresses of all user plane functions in the N user plane functions that are located after the first user plane function; a first processor, configured to generate a first IP header enhancement message according to the IP header enhancement message construction rule, where the first IP header enhancement message includes addresses of all other user plane functions among the N user plane functions except the first user plane function; The first transceiver is also used to send the first IP header enhanced message.

17. A user plane function, characterized in that The user plane function is a second user plane function, the second user plane function is the i-th user plane function at which the message arrives in the core network user plane forwarding path, the core network user plane forwarding path includes N user plane functions, N is an integer not less than 2, and i is an integer greater than 1 and less than N; The user plane functions include: A second transceiver is configured to receive a second IP header enhanced message sent by an i-1th user plane function in the core network user plane forwarding path, where the segment address list of the second IP header enhanced message includes addresses of all subsequent user plane functions located after the i-1th user plane function in the core network user plane forwarding path; a second processor, configured to determine, based on the segment address list in the second IP header enhanced message, whether it is the last user plane function in the core network user plane forwarding path; and if it is determined that the second user plane function is not the last user plane function, generate a third IP header enhanced message according to the second IP header enhanced message, where the segment address list in the third IP header enhanced message includes addresses of all subsequent user plane functions in the core network user plane forwarding path that are located after the i-th user plane function; The second transceiver is used to send the third IP header enhanced message.

18. A user plane function, characterized in that The user plane function is a third user plane function, which is the last user plane function at which a message arrives in a core network user plane forwarding path. The core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2. The user plane function includes: A third transceiver is configured to receive a fourth IP header enhanced message sent by the N-1th user plane function in the core network user plane forwarding path, where the segment address list of the fourth IP header enhanced message includes addresses of all subsequent user plane functions located after the N-1th user plane function in the user plane function forwarding path; A third processor is configured to generate a target message according to the fourth IP header enhanced message; The third transceiver is used to send the target message to the target network; Wherein, when the target message is an IP message, the target network is a data network; when the target message is a GTP-U message, the target network is a wireless access network.

19. A SMF, characterized in that The SMF includes: a fourth processor, configured to determine, based on at least one of the terminal's location information, a network policy, a network slice identifier, and a data network name, a core network user plane forwarding path associated with the first terminal, where the core network user plane forwarding path includes N user plane functions, where N is an integer not less than 2; A fourth transceiver is used to send an IP header enhancement message construction rule to the first user plane function, where the IP header enhancement message construction rule is used to generate a first IP header enhancement message, where the first IP header enhancement message includes the addresses of all other user plane functions among the N user plane functions except the first user plane function, and the first user plane function is the first user plane function where the message arrives in the core network user plane forwarding path.

20. A communication device, characterized in that: comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein when the program or instruction is executed by the processor, the steps of the message transmission method according to any one of claims 1 to 3 are implemented; or, the steps of the message transmission method according to any one of claims 4 to 6; or, the steps of the message transmission method according to any one of claims 7 to 10; Or, the steps of the message transmission method as described in any one of claims 11 to 15.

21. A readable storage medium, characterized in that The readable storage medium stores a program or instruction, and when the program or instruction is executed by the processor, the steps of the message transmission method according to any one of claims 1 to 3 are implemented; Or, the steps of the message transmission method according to any one of claims 4 to 6; Or, the steps of the message transmission method according to any one of claims 7 to 10; Or, the steps of the message transmission method as described in any one of claims 11 to 15.

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