WO2023138547A1

WO2023138547A1 - Tunnel information sending method and apparatus

Info

Publication number: WO2023138547A1
Application number: PCT/CN2023/072490
Authority: WO
Inventors: 宋雅琴; 程志密; 刘强
Original assignee: 大唐移动通信设备有限公司
Priority date: 2022-01-21
Filing date: 2023-01-17
Publication date: 2023-07-27
Also published as: CN116528398A

Abstract

Provided in the embodiments of the present disclosure are a tunnel information sending method and apparatus. The method applied to a first endpoint of a tunnel comprises: on the basis of the address of a second endpoint of a tunnel, sending a first user plane message to the second endpoint of the tunnel, the first user plane message comprising tunnel information corresponding to a first endpoint of the tunnel. By means of the tunnel information sending method and apparatus provided by the embodiments of the present disclosure, tunnel information is sent by means of a user plane message, so that the time for tunnel establishment or modification is shortened, and the processing overhead of a control plane function is reduced by reducing the number of session messages executed by network function entities, thus improving the tunnel message exchange efficiency.

Description

A method and device for sending tunnel information

Cross References to Related Applications

This disclosure claims the priority of the Chinese patent application with the application number 202210072700.6 filed on January 21, 2022, and the title of the invention is "A Method and Device for Tunnel Information Transmission", which is fully incorporated herein by reference.

technical field

The present disclosure relates to the technical field of wireless communication, and in particular, to a tunnel information sending method and device.

Background technique

The 5G system (5th-Generation System, 5GS) follows the characteristics of Control and User Plane Separation (CUPS). The 5G core network (5th-Generation Core Network, 5GC) control plane communicates through the service interface (SBI), and the 5GC user plane uses the GTP-U protocol.

The GTP-U tunnel is used to forward packets between GTP-U entities, and a GTP-U tunnel includes the tunnel endpoint identifier (Tunnel endpoint identifier, TEID), IP address and UDP port number identifier of each node. Among them, the UDP destination port number uses the registered port number 2152. TEID is used to indicate which GTP-U tunnel a specific T-PDU (original packet) belongs to. During the tunnel establishment process, the receiving endpoint of the GTP-U tunnel locally assigns the TEID value and IP address that must be used by the sending end. This information is called tunnel information (Tunnel Info). Tunneling information is exchanged between GTP-U entities through control plane messages, such as 5GC SBIs and/or NG Application Protocol (NG Application Protocol, NGAP).

Therefore, after the receiving end point (access network side or UPF) of the N3/N9 interface GTP-U tunnel of 5GS distributes the tunnel information locally, it first sends it to the control plane functional entity, and then sends it to the opposite end of the tunnel through the control plane functional entity, which brings about the problem of low tunnel information exchange efficiency.

Contents of the invention

Aiming at the problems existing in related technologies, the embodiments of the present disclosure provide a method and device for sending tunnel information.

In a first aspect, an embodiment of the present disclosure provides a method for sending tunnel information, which is applied to a first end point of a tunnel, and the method includes:

Based on the address of the second end point of the tunnel, send a first user plane message to the second end point of the tunnel, where the first user plane message includes tunnel information corresponding to the first end point of the tunnel.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the first user plane message is any of the following:

General Packet Radio Service User Plane Tunneling Protocol GTP-U signaling message;

User plane function UPF service based on service interface;

The first packet message used for tunnel information exchange.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the GTP-U signaling message is any of the following:

Signaling messages of new message types;

Add a signaling message with a flag bit on the message type;

Signaling message of the new GTP-U extension header.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the UPF service based on the service interface includes:

After allocating the tunnel information, the first end point of the tunnel notifies the second end point of the tunnel through a Notify operation.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the notifying the second end point of the tunnel through the Notify operation includes:

In the case that the network function entity subscribes to the tunnel information through Subscribe, the second end point of the tunnel is notified through a Notify operation.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the first user plane message further includes a second session identifier, and the second session identifier is used to distinguish the session to which the tunnel information belongs. and corresponding to the second end point of the tunnel.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, before sending the first user plane message to the second end point of the tunnel, the method further includes:

Receive the address of the second end point of the tunnel and/or the second session identifier sent by the network function entity.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the second session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the method further includes any of the following or a combination thereof:

After allocating the tunnel information corresponding to the second session identifier, sending the tunnel information to the network function entity;

Receive a second user plane message sent by the second end point of the tunnel, where the second user plane message includes a first session identifier and tunnel information corresponding to the second end point of the tunnel; the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first end point of the tunnel.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the first session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the first endpoint of the tunnel; or

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, when the first end point of the tunnel is a newly inserted end point of the target tunnel, the method further includes:

Receiving related information sent by the network function entity, where the related information includes tunnel information corresponding to one or more associated tunnel endpoints related to the target tunnel.

Optionally, according to the method for sending tunnel information in an embodiment of the present disclosure, the relevant information further includes an address and/or a session identifier corresponding to an associated tunnel endpoint related to the target tunnel, and the meeting The session identifier is used to distinguish the session to which the tunnel information belongs;

The method also includes:

Based on the address corresponding to each associated tunnel endpoint, send a user plane message to each associated tunnel endpoint, where the user plane message includes tunnel information corresponding to the first tunnel endpoint and a session identifier corresponding to the associated tunnel endpoint.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the method is applied to the N3 interface and/or the N9 interface.

In the second aspect, the embodiment of the present disclosure also provides a method for sending tunnel information, which is applied to a network function entity, and the method includes:

sending the second session identifier and/or the address of the second end point of the tunnel to the first end point of the tunnel;

The address of the second end point of the tunnel is used by the first end point of the tunnel to send a user plane message to the second end point of the tunnel, where the user plane message includes tunnel information corresponding to the first end point of the tunnel; the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.

receiving the tunnel information sent by the first endpoint of the tunnel;

Sending first related information and second related information to a newly inserted tunnel endpoint; the first related information includes tunnel information corresponding to the first tunnel endpoint, and the second related information includes tunnel information corresponding to the tunnel second endpoint.

Optionally, according to the method for sending tunnel information according to an embodiment of the present disclosure, the first related information further includes an address corresponding to the first endpoint of the tunnel and/or a first session identifier, the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first endpoint of the tunnel;

The second related information further includes an address corresponding to the second end point of the tunnel and/or the second session identifier.

Network function entity identifier and N4 session identifier N4 Session ID, the N4 Session ID corresponds to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID;

The first session identifier includes:

In the third aspect, the embodiment of the present disclosure also provides a tunnel first endpoint device, including a memory, including a memory, a transceiver, and a processor:

The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and implement the steps of the tunnel information sending method described in the first aspect above.

In a fourth aspect, an embodiment of the present disclosure further provides a network function entity, including a memory, including a memory, a transceiver, and a processor:

The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and implement the steps of the tunnel information sending method described in the second aspect above.

In the fifth aspect, the embodiment of the present disclosure further provides a processor-readable storage medium, the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the steps of the tunnel information sending method described in the first aspect.

In the sixth aspect, the embodiments of the present disclosure further provide a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the steps of the tunnel information sending method described in the second aspect.

The method and device for sending tunnel information provided by the embodiments of the present disclosure send tunnel information through user plane messages, which shortens the time for tunnel establishment or modification, and reduces the processing overhead of control plane functions by reducing the number of session messages executed by network functional entities, thereby improving the efficiency of tunnel message exchange.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or related technologies. Obviously, the accompanying drawings in the following description are some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative work.

FIG. 1 is a schematic diagram of the 5GS transmission process of the GTP-U tunnel provided by the present disclosure;

FIG. 2 is a schematic diagram of an N4 session establishment process provided by the present disclosure;

FIG. 3 is a schematic diagram of a GTP-U tunnel establishment process provided by the present disclosure;

FIG. 4 is a schematic diagram of a GTP-U tunnel modification process provided by the present disclosure;

Fig. 5 is one of the schematic flow diagrams of the method for sending tunnel information provided by an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of a GTP-U tunnel establishment process based on a user plane message provided by an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of a GTP-U tunnel modification process based on a user plane message provided by an embodiment of the present disclosure;

FIG. 8 is the second schematic flow diagram of the method for sending tunnel information provided by an embodiment of the present disclosure;

FIG. 9 is the third schematic flow diagram of the method for sending tunnel information provided by an embodiment of the present disclosure;

FIG. 10 is a fourth schematic flow diagram of a method for sending tunnel information provided by an embodiment of the present disclosure;

FIG. 11 is a schematic structural diagram of a tunnel first endpoint device provided by an embodiment of the present disclosure;

FIG. 12 is a schematic structural diagram of a network function entity provided by an embodiment of the present disclosure;

FIG. 13 is one of the structural schematic diagrams of the tunnel information sending device provided by the embodiment of the present disclosure;

FIG. 14 is a second structural schematic diagram of an apparatus for sending tunnel information provided by an embodiment of the present disclosure.

Detailed ways

The term "and/or" in the embodiments of the present disclosure describes the association relationship of associated objects, and means that there may be three kinds of relationships, for example, A and/or B may mean: A exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the contextual objects are an "or" relationship.

The term "plurality" in the embodiments of the present disclosure refers to two or more, and other quantifiers are similar.

The following will clearly and completely describe the technical solutions in the embodiments of the present disclosure with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, not all of them. Based on the embodiments in the present disclosure, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present disclosure.

The technical solutions provided by the embodiments of the present disclosure can be applied to various systems, especially 5G systems. For example, the applicable system may be global system of mobile communication (GSM) system, code division multiple access (CDMA) system, wideband code division multiple access (WCDMA) general packet radio service (general packet radio service, GPRS) system, long term evolution (long term evolution) , LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, long term evolution advanced (LTE-A) system, universal mobile telecommunications system (UMTS), global interconnection microwave access (worldwide interoperability for Microwave access, WiMAX) system, 5G new air interface (New Radio, NR) system, etc. These various systems include end devices and network devices. The system may also include a core network part, such as an evolved packet system (Evloved Packet System, EPS), a 5G system (5GS), and the like.

The terminal device (such as UE) involved in the embodiments of the present disclosure may be a device that provides voice and/or data connectivity to users, a handheld device with a wireless connection function, or other processing devices connected to a wireless modem. In different systems, the names of the terminal equipment may be different. For example, in a 5G system, the terminal equipment may be called user equipment (User Equipment, UE). Wireless terminal equipment can communicate with one or more core networks (Core Network, CN) via a radio access network (Radio Access Network, RAN). The wireless terminal equipment can be mobile terminal equipment, such as mobile phones (or called "cellular" phones) and computers with mobile terminal equipment, such as portable, pocket, handheld, computer built-in or vehicle-mounted mobile devices, which exchange language and/or data with the radio access network. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiated Protocol (SIP) phones, Wireless Local Loop (WLL) stations, personal Digital Assistant (Personal Digital Assistant, PDA) and other devices. A wireless terminal device may also be called a system, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, an access point, a remote terminal, an access terminal, a user terminal, a user agent, a user A device (user device) is not limited in the embodiments of the present disclosure.

The network device involved in the embodiments of the present disclosure may be a base station, and the base station may include multiple cells that provide services for terminals. Depending on the specific application, the base station can also be called an access point, or it can be a device in the access network that communicates with the wireless terminal device through one or more sectors on the air interface, or other names. The network device may be operable to interchange received over-the-air frames with Internet Protocol (IP) packets and act as a router between the wireless end device and the rest of the access network, which may include an Internet Protocol (IP) communications network. Network devices may also coordinate attribute management for the air interface. For example, the network device involved in the embodiments of the present disclosure may be a network device (Base Transceiver Station, BTS) in Global System for Mobile communications (GSM) or Code Division Multiple Access (CDMA), or a network device (NodeB) in Wide-band Code Division Multiple Access (WCDMA), It can also be an evolved network device (evolutional Node B, eNB or e-NodeB) in a long term evolution (LTE) system, a 5G base station (gNB) in a 5G network architecture (next generation system), or a home evolved base station (Home evolved Node B, HeNB), a relay node (relay node), a home base station (femto), a pico base station (pico) etc. are not limited in the embodiments of the present disclosure. In some network structures, a network device may include a centralized unit (centralized unit, CU) node and a distributed unit (distributed unit, DU) node, and the centralized unit and the distributed unit may also be arranged geographically separately.

Since the birth of the mobile communication field, the general packet radio service user plane tunneling protocol (GPRS Tunneling Protocol, GTP) has been used for data domain communication. Among them, GTP-C is a control plane protocol, which is used for the establishment, modification and deletion of session tunnels, etc.; GTP-U is a user plane protocol, which is used for data plane transmission between the mobile network radio access network and the core network, as well as within the core network.

With the emergence and development of 5G, the 5G system (5th-Generation System, 5GS) architecture is defined as Service-Based Architecture (SBA), and the 5G Core Network (5GC) control plane functions no longer use GTP-C, but interact through the Service-Based Interface (SBI) interface. The data plane of the 5G core network is the same as that of 4G, and the GTP-U protocol is still used, and the QoS Flow Identifier (QFI) is extended on the basis of the original protocol to better meet the forwarding needs of the 5G data plane.

5GS follows the control and user plane separation (CUPS) feature. The N4 interface is used between the Session Management Function (SMF) and the User Plane Function (UPF). The N4 control plane uses the Packet Forwarding Control Protocol (PFCP) for communication, and the N4 data plane uses the GTP-U protocol for communication. The N3 interface and N9 interface on the user plane adopt the GTP-U protocol.

The GTP-U tunnel is used to forward packets between GTP-U entities. A GTP-U tunnel includes the tunnel endpoint identifier (Tunnel Endpoint Identifier, TEID), IP address and UDP port number identification of each node. GTP-U messages are sent between GTP user plane tunnels, including GTP-U signaling messages or G-PDU messages.

The GTP Encapsulated User Plane Data Unit (G-PDU) is a common user plane message carrying the original Transport Protocol Data Unit (T-PDU). Wherein, the T-PDU may be an IP data packet, an Ethernet or an unstructured PDU data frame from the UE or an external DN. The GTP-U signaling message is used for user plane path management or user plane tunnel management, and the format of the GTP-U message header is shown in Table 1.

Table 1. GTP-U message header format

The GTP header has a variable length, including 8 bytes of fixed fields, and optional fields such as sequence number, N-PDU number, and next extension header type. The GTP-U message header fields are shown in Table 2.

Table 2. GTP-U packet header fields

The tunnel endpoint identifier (TEID) in the GTP header is used to indicate which GTP-U tunnel a specific T-PDU belongs to. In this way, packets are multiplexed and demultiplexed by GTP-U between a specific pair of tunnel endpoints. TEID values are exchanged between GTP-U entity pairs using control plane protocols, such as GTPv1-C and RANAP, GTPv2-C and S1-AP, 5GC SBIs and/or NGAP.

But in the following GTP-U signaling message, the TEID is set to all zeros:

Echo Request/Response (response request/response);

Supported Extension Headers notification messages (supported extension header notification messages);

Error Indication message (error indication message).

The GTP-U message is shown in Table 3, including the G-PDU message carrying the original data packet T-PDU and the GTP-U signaling message. The G-PDU may include extended headers, but shall not include any information elements (Information Element, IE). GTP-U signaling information is further divided into path management messages and tunnel management messages. Path management messages include: Echo Request, Echo Response, and Supported Extension Headers Notification; tunnel management messages include: Error Indication, End Marker, and Tunnel Status.

Table 3. GTP-U messages

If GTP-U needs to expand message types in the future, it can be seen in the TS29.060 document describing the GTP protocol that the reserved unused message types are 0, 8-15, 24-25, 63-69, 106-111, 122-127, 130-239, 242-252.

A GTP-U signaling message may contain multiple IEs. The GTP information element shall use TLV (Type, Length, Value) or TV (Type, Value) encoding format. In signaling messages, information elements shall be sorted in ascending order of the type field. The Length field contains the length of the information element (Value), excluding the lengths of the Type and Length fields.

When using the TV format, Bit 8 in the type field is set to 0 (that is, 0-127), and when using the TLV format, it is set to 1 (that is, above 128).

Since the type field is 8 bits, the default supported IE type is 0-255. If IE Type Value=238, the supported extension type is 2 bytes (that is, 236-65535, all reserved and unused at present). The information elements with the IE type extension field are shown in Table 4.

Table 4. Information elements with IE type extension fields

The GTP-U information elements described in the existing protocol are shown in Table 5, in which 231-237 are reserved and unused.

Table 5. Information Elements (IEs) in GTP-U

Figure 1 is a schematic diagram of the 5GS transmission process of the GTP-U tunnel provided by this disclosure. As shown in Figure 1, the transmission process of 5GS uplink data is: UE sends data (internal IP header and payload), and transmits it to the base station (R)AN through a wireless channel. The base station encapsulates the UE data packet into a GTP-U message, and sets the TEID of the GTP-U header as the tunnel peer identifier "1", and sends it to N3UPF (UPF terminating N3reference point) through the N3 interface, that is, the UPF in the figure 1. N3UPF decapsulates the GTP-U message, obtains the corresponding TEID and other information, judges the tunnel to which the message belongs, executes Packet Detection Rule (PDR) and forwarding action rule (Forwarding Action Rule, FAR) and other actions, and re-encapsulates the GTP-U message with TEID set to "2", and forwards it to UPF2 (PSA) through the N9 interface. UPF2 is the PDU Session Anchor (PDU Session Anchor, PSA). UPF2 (PSA) decapsulates the GTP-U message to obtain the data sent by the UE, and sends it to the external network DN through the N6 interface according to the routing and forwarding rules. On the contrary, it is the downlink data transmission process.

A GTP-U tunnel includes the TEID, IP address and UDP port number identification of each node at the tunnel endpoint. Wherein, the UDP destination port number is the registered port number 2152. Therefore, during tunnel establishment, the receiving endpoint of the GTP-U tunnel needs to locally assign the TEID value and IP address that must be used by the sending end. address and pass it to the sending endpoint. The TEID and IP address that identify the tunnel are called tunnel information (Tunnel Info).

The N4 session establishment process is used to create an initial N4 session context for a PDU session at UPF. SMF allocates a new N4 Session ID and provides it to UPF. The N4 Session ID is stored by both entities and used to identify the N4 session context during their interaction. The SMF also stores the relationship between the UE's N4Session ID and the PDU session.

Figure 2 is a schematic diagram of the N4 session establishment process provided by the present disclosure. As shown in Figure 2, the N4 session establishment process includes:

1. The SMF receives a trigger requesting to establish a new PDU session or to change the UPF of an established PDU session.

2. SMF sends N4session establishment request message to UPF, which contains structured control information defining the behavior required by UPF, including PDR (Packet Detection Rule) and FAR (Forwarding Action Rule).

3. The UPF responds with the N4session establishment response message, which contains any information that the UPF must provide to the SMF in response to the received control information.

4. The SMF interacts with the network function (such as AMF or PCF) that triggers this process.

The 5G core network interacts through a service-based interface (SBI). Servitization in R15 is only for the control plane. User plane network elements such as UPF do not provide service interfaces for other network elements to use. In R16, entities such as user plane network functions are also further transformed into services to provide external services.

The UPF service interface is as follows:

In 5GC, UPF provides services for NEF and AF through the Nupf-based service interface. UPF supports the following functions: notification of QoS monitoring information.

The content of UPF service is shown in Table 6:

Table 6. NF services provided by UPF

The Nupf_EventExposure service can expose UPF related information to other network functions (NFs). One operation of this service is to notify (Notify) PDU session events to other NFs.

The following events can be notified to a NF consumer: QoS Monitoring for URLLC, the notification may contain the following information: QoS monitoring results, such as the end-to-end delay of a specific QoS flow for a specific PDU session.

Since the standardization of UPF services is in its infancy, the current 3GPP protocol provides relatively few UPF services and related operations, and more UPF services may appear in the future.

The basic process of GTP-U tunnel management includes GTP-U tunnel establishment and GTP-U tunnel modification.

GTP-U tunnel establishment:

FIG. 3 is a schematic diagram of a GTP-U tunnel establishment process provided by the present disclosure. It can be understood that each small step in the figure has no strict sequence, such as steps 1.1 and 1.2.

As shown in Figure 3, the GTP-U establishment process includes:

(1) The SMF sends N4 Session Establishment Request messages to the two UPFs at both ends of a GTP-U tunnel. Among them, before the N4 session is established, the SMF first allocates the N4 Session ID for the N4 session. The request contains structured control information such as PDR and FAR defining the required behavior of the UPF, and the N4 Session ID used to identify the N4 session context.

(2) After the UPF receives the N4 Session Establishment Request, it executes the required behavior of the structured control information, and allocates the required UL and/or DL CN Tunnel Info for the N4 session, including TEID and IP address.

(3) UPF replies N4 Session Establishment Response message to SMF, carrying Tunnel Info in the response.

(4) The SMF sends N4 Session Modification Request messages to the two UPFs at both ends of a GTP-U tunnel, carrying the Tunnel Info at the opposite end of the tunnel.

(5) UPF stores Tunnel Info and replies through N4 Session Establishment/Modification Response.

GTP-U tunnel modification:

If the UPF at one end of a GTP-U tunnel changes, such as modifying/inserting/deleting a certain UPF, the Tunnel Info of a certain endpoint of the GTP-U tunnel needs to be modified. Figure 4 is a schematic diagram of the GTP-U tunnel modification process provided by the present disclosure. As shown in Figure 4, if a UPF is inserted after the tunnel shown in Figure 4 is established, the basic process of inserting the UPF involving N9 tunnel modification is as follows:

(1) The SMF sends the N4 Session Establishment Request message to the inserted UPF. The request includes structured control information PDR and FAR defining the required behavior of the UPF, the N4 Session ID used to identify the N4 session context, and the Tunnel Info of the tunnel peer.

(2) After the inserted UPF receives the message, it stores the Tunnel Info at the opposite end of the tunnel, and distributes the local UL and DL Tunnel Info for the session;

(3) The allocated Tunnel Info is carried to SMF in N4 Session Establishment Response;

(4) The SMF sends N4 Session Modification Request messages to the UPFs at the two tunnel peers involved in the newly inserted UPF.

(5) The UPF replies with the N4 Session Modification Response message.

5GS introduces the CUPS feature. The control plane function SMF and the user plane function UPF are separated. The Tunnel Info of both endpoints of a GTP-U tunnel needs to be forwarded to the user plane function at the opposite end of the tunnel through the control plane function. The main problems are as follows:

Long tunnel establishment/modification time: Tunnel Info is exchanged through control plane messages, resulting in long time-consuming tunnel information exchange and long delays in tunnel establishment/modification.

High control plane function overhead: Tunnel Info needs to complete information exchange through the control plane function, resulting in a large number of N4 Session Modification Request/Response executed by SMF, which increases the processing overhead of the control plane function.

Referring to FIG. 5, FIG. 5 is one of the flow diagrams of the tunnel information sending method provided by the embodiment of the present disclosure. The method can be applied to the first end point of the tunnel, including:

Step 510: Based on the address of the second end point of the tunnel, send a first user plane message to the second end point of the tunnel, where the first user plane message includes tunnel information corresponding to the first end point of the tunnel.

Specifically, the first end point of the tunnel refers to the receiving end of the GTP-U tunnel, and the second end point of the tunnel refers to the sending end of the GTP-U tunnel. The tunnel information corresponding to the first end point of the tunnel includes a tunnel end point identifier TEID generated by the first end point of the tunnel and used by the second end point of the tunnel, and an address used for data routing. It can be understood that the address may be an IP address, or an address in another form, such as a UPF domain name, and the specific form of the address is not limited in this embodiment of the present disclosure.

sending the first user plane message to the second end point of the tunnel, the purpose of the first user plane message The address is the address of the second end point of the tunnel. The address of the second end point of the tunnel may be pre-stored by the first end point of the tunnel, or pre-obtained from other network functional entities or nodes. Exemplarily, if the first end point of the tunnel has sent a message to the second end point of the tunnel or received a message sent by the second end point of the tunnel, the first end point of the tunnel stores the address of the second end point of the tunnel.

In the tunnel information sending method provided by the embodiments of the present disclosure, the first end point of the tunnel sends tunnel information to the second end point of the tunnel through a user plane message. Compared with the sending method in which the tunnel information is first sent to the control plane functional entity and then sent to the opposite end of the tunnel in the related art, the tunnel information sending method of the present disclosure shortens the time for establishing or modifying the tunnel, and reduces the processing overhead of the control plane function by reducing the number of session messages executed by the network functional entity. Taking the session management function entity SMF as an example, it reduces the SMF execution of N4 Session Modification Request/Response , thus improving the efficiency of tunnel message exchange.

Optionally, the first user plane message further includes a second session identifier, where the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.

Specifically, the first user plane message further includes a second session identifier, and the second end point of the tunnel may determine the PDU session corresponding to the second session identifier based on the second session identifier, thereby determining the session corresponding to the tunnel information carried in the first user plane message.

Optionally, before sending the first user plane message to the second end point of the tunnel, the method further includes:

In one embodiment, the N4 establishment request message sent by the session management function entity SMF is received, the N4 establishment request message includes the address of the second end point of the tunnel and the second session identifier, the first end point of the tunnel allocates tunnel information, and sends a first user plane message carrying the tunnel information and the second session identifier to the second end point of the tunnel, and the destination address of the first user plane message is the address of the second end point of the tunnel sent by the SMF. It can be understood that the first end point of the tunnel may pre-store the second session identifier, for example, the information has been transmitted in the previous N4 request message.

Optionally, the second session identifier includes:

Network function entity identifier and N4 session identifier N4 Session ID, the N4 Session ID and said tunnel second endpoint corresponds to; or

For the case where the second session identifier is a network function entity identifier and an N4 session identifier N4 Session ID, the network function entity NF may include SMF, and may also include other network function entities related to the GTP-U tunnel. The N4 session corresponding to the PDU session is established between the NF and the UPF. The NF allocates the N4 Session ID for the N4 session. Both the NF and the UPF store the N4 Session ID. The N4 Session ID is used to identify the N4 session context during the interaction between the NF and the UPF. It can be understood that the N4 interface can be used between the NF and the UPF, and other interface types of sessions can also be established through other interfaces. The session types and corresponding session identifiers established between the NF and the UPF based on other interfaces should also fall within the protection scope of the present disclosure. Based on the network function entity identifier and the N4 session identifier, the second end point of the tunnel can uniquely determine a PDU session or an N4 session, thereby determining the session to which the tunnel information carried in the first user plane message belongs.

For the case where the second session identifier is a permanent identity identifier SUPI and a protocol data unit session identifier PDU Session ID, the permanent identity identifier SUPI refers to the identity identifier of the user terminal (User Equipment, UE) that initiates the PDU session, and the PDU Session ID is allocated by the PDU session initiated by the UE, and is used to uniquely identify the packet data unit session of the user equipment. Based on SUPI and PDU Session ID, the second end point of the tunnel can uniquely determine a PDU session, thereby determining the session to which the tunnel information carried in the first user plane message belongs.

It can be understood that, since the PDU session and the N4 session are in one-to-one correspondence, the session to which the tunnel information belongs may be a PDU session or an N4 session.

Optionally, the method also includes any or a combination of the following:

Sending the tunnel information to the network function entity after allocating the tunnel information corresponding to the second session identifier means that the first end point of the tunnel allocates a tunnel for use by the second end point of the tunnel After receiving the tunnel information, the network function entity stores the tunnel information after receiving the tunnel information sent by the first end point of the tunnel, and can send the tunnel information to other network elements that need the tunnel information to improve data transmission efficiency.

Receiving the second user plane message sent by the second end point of the tunnel means that the first end point of the tunnel receives the second user plane message sent by the second end point of the tunnel. The second user plane message includes tunnel information assigned by the second end point of the tunnel and used by the first end point of the tunnel. The second user plane message also includes a first session identifier corresponding to the first end point of the tunnel. The first end point of the tunnel can identify the session to which the tunnel information carried in the second user plane message belongs based on the first session identifier.

Optionally, the first session identifier includes:

The first session identifier corresponds to the first end point of the tunnel, and is used by the first end point of the tunnel to distinguish the session to which the received tunnel information belongs. For the introduction of network function entity identification and N4 Session ID, as well as the introduction of SUPI and PDU Session ID, refer to the introduction above, and will not repeat them here.

Referring to FIG. 6, FIG. 6 is a schematic diagram of a GTP-U tunnel establishment process based on a user plane message provided by an embodiment of the present disclosure. The GTP-U tunnel establishment steps are as follows:

(1) The SMF sends N4 session establishment request messages (N4 Session Establishment Request Message) to the two UPFs at both ends of a GTP-U tunnel.

UPF1 is used as the first end point of the tunnel, and UPF2 at the opposite end of the tunnel is used as the second end point of the tunnel. UPF1 allocates tunnel information including TEID and address for UPF2 to send GTP-U messages to UPF1. Correspondingly, the case where UPF2 is used as the first end point of the tunnel will not be described again.

Before the N4 session is established, the SMF first allocates an N4 Session ID for the N4 session. It can be understood that a first N4 session is established between the SMF and UPF1, and a second N4 session is established between the SMF and UPF2. Therefore, the N4 Session ID allocated by the SMF for the first N4 session corresponds to UPF1, and the N4 Session ID allocated by the SMF for the second N4 session corresponds to UPF2. The request message contains structured control information such as PDR and FAR defining the required behavior of the UPF, the N4 Session ID used to identify the N4 session context, and the IP address and session ID of another UPF. The session ID can be It is SMF ID and N4 Session ID, it can also be SUPI and PDU Session ID, etc.

(3) After the UPF allocates Tunnel Info, it sends the allocated Tunnel Info to another UPF at the peer end of the tunnel through a user plane message. The destination address of the user plane message is the address of the peer end. The notification carries the UL or DL identifier, and the notification also carries the corresponding session identifier of the peer end, which is used by the UPF at the peer end of the tunnel to identify the tunnel to which the Tunnel Info belongs.

Optionally, after receiving the Tunnel Info message, the tunnel peer directly stores the Tunnel Info information if the session-related context has been constructed. Otherwise, the Tunnel Info can be temporarily stored and a timer can be set. When the timer expires and the related N4 message is still not received, it can be considered that an abnormal situation has occurred. At this point, the UPF should send a relevant abnormal signal to the SMF, and the specific method is out of the scope of this patent.

(4) After UPF sends Tunnel Info, it replies to SMF with N4 Session Establishment Response message, and the response still carries Tunnel Info.

It can be understood that the sequence of steps 1.1 and 1.2 in FIG. 6 is not limited, and the same process is performed for steps 2.1 and 2.2, steps 3.1 and 3.2, and steps 4.1 and 4.2.

Optionally, the first user plane message is any of the following:

User plane function UPF service based on service interface;

A first packet message used for tunnel information exchange, where the first packet message may be a newly defined packet message.

The first user plane message is a first packet message used for tunnel information exchange, the first packet message may be a newly defined packet message, and the newly defined packet message refers to a newly defined packet message that is different from an existing message type and used for tunnel information exchange. The first message may be any message for information transfer between UPFs, for example, it may include a newly defined IPv6 extension header, a new network layer message or a new IP-based upper layer protocol and other message messages. It should be understood that the above-mentioned message messages are only examples for easy understanding, and should not constitute any limitation to the present disclosure; Other types of message messages that can realize tunnel information transmission and/or switching functions appearing in the domain or appearing in the future can be applied here.

The fact that the first user plane message is a general packet radio service user plane tunneling protocol GTP-U signaling message means that a GTP-U signaling message carrying tunnel information can be constructed as the first user plane message.

Optionally, the GTP-U signaling message is any of the following:

Signaling messages of new message types;

A signaling message with a flag bit added to the message type.

Signaling message of the new GTP-U extension header.

For the signaling message that the GTP-U signaling message is a new message type, according to the TS29.060 document of the GTP protocol, the reserved unused message types (Message Type) are 0, 8-15, 24-25, 63-69, 106-111, 122-127, 130-239 and 242-252, so a message type can be selected as the one supporting tunnel information exchange in the reserved unused message types The GTP-U signaling message may be called a tunnel information signaling message (Tunnel Info Signal).

Referring to Table 7, Table 7 is the information element (IE) of the tunnel information signaling message provided by the embodiment of the present disclosure.

Table 7. Information elements of the tunnel information signaling message

Tunnel Endpoint Identifier Data I is the TEID assigned to the first endpoint of the tunnel, and GTP-U Peer Address is the address assigned to the first endpoint of the tunnel. GTP-U node session identifier (GTP-U Peer Session Identifier) is a newly defined IE, and its IE type number can be one of the reserved 231-237. This information element is designed as shown, mainly including the UL or DL flag of the tunnel to which the tunnel information belongs, and the session identifier to distinguish the session to which the tunnel information belongs. The session ID can be SMF ID and N4 Session ID, or SUPI and PDU Session ID, etc.

Table 8. Information elements for GTP-U node session identification

For the GTP-U signaling message is a signaling message with a new flag bit on the message type, the TEID can be carried in the GTP-U header of the existing message type, and the UL/DL flag can also use the reserved bit4 of the first byte of the GTP-U header. 0 indicates that it does not support Tunnel Info exchange, and 1 indicates that it supports Tunnel Info exchange. Exemplarily, a flag bit is added to a tunnel status message (Tunnel Status message), so as to realize sending the tunnel information allocated by the first end point of the tunnel to the second end point of the tunnel.

The GTP-U signaling message is a new GTP-U extension header signaling message. Combining Table 1 and Table 2, it can be seen that GTP-U supports an extension header (also called an extension header, the disclosure does not limit the name), and the format is shown in Table 9.

Table 9. GTP-U supports extended headers

The extension header defined by the existing protocol is shown in Table 10:

Table 10. Extension headers defined by existing protocols

Therefore, a new GTP-U extension header can be defined to support the transmission of tunnel information. For example, use "10001010" to represent "Tunnel Info Container".

As for the first user plane message being a user plane function UPF service based on a service interface, for example, the Namf_EventExposure service may be used as the first user plane message, and the Nupf_EventExposure service may expose UPF related information to other network function entities.

Specifically, the NF service provided by UPF shown in Table 6 is expanded. The expanded NF service is shown in Table 11. UPF is added as a consumer. The original protocol Nupf_EventExposure notification event includes QoS monitoring results. This disclosure increases tunnel information exposure.

Table 11. NF services provided by UPF of this disclosure

Optionally, the UPF service based on the service interface includes:

After allocating the tunnel information, the first end point of the tunnel notifies the second end point of the tunnel through a Notify operation. Exemplarily, when an N4 session is established or modified, the SMF carries the UPF information, after the first end point of the tunnel distributes the tunnel information, the tunnel information is provided to the opposite end of the tunnel (the second end point of the tunnel) through the Notify operation of Nupf_EventExposure.

The notifying the second endpoint of the tunnel through the Notify operation includes:

Specifically, based on the Namf_EventExposure service, the network function entity can subscribe to event notifications by itself or on behalf of another network function entity and obtain event notifications. Therefore, the network function entity can subscribe to the tunnel information on behalf of the second endpoint of the tunnel. After the tunnel information is allocated at the first endpoint of the tunnel, the tunnel information is provided to the second endpoint of the tunnel through the Notify operation of Nupf_EventExposure.

Optionally, in the case where the first end point of the tunnel is a newly inserted end point of the target tunnel, the method further includes:

Referring to FIG. 7, FIG. 7 is a schematic diagram of a GTP-U tunnel modification process based on user plane messages provided by an embodiment of the present disclosure. The target tunnel refers to the GTP-U tunnel that needs to be modified. As shown in FIG. 7, in the case where UPF2 is not inserted, the GTP-U tunnel between UPF3 and UPF1 is the target tunnel; The tunnel information corresponding to UPF3 and the tunnel information corresponding to UPF1 sent by the network function entity are received. Exemplarily, in the case where the network functional entity is an SMF, the session modification request message or the session establishment request message sent by the SMF is received, and the session modification request message or the session establishment request message includes tunnel information corresponding to the tunnel endpoints at both ends of the target tunnel; in the above case, UPF2 needs to receive its associated tunnel endpoints, that is, UPF1 and UPF3 and the tunnel information of the endpoints corresponding to UPF2.

Optionally, in the case where the tunnel information sending method provided by the embodiments of the present disclosure is only applied to the N9 interface, the insertion position of UPF2 may be in front of UPF3, that is, the connections of multiple UPFs are: UPF2, UPF3, and UPF1 in sequence; in this case, UPF2 only needs to receive the tunnel information of its corresponding endpoint (UPF3).

Optionally, the data transmission links are: UPF1, UPF2, and PSA in sequence. When UPF2 needs to be replaced with UPF3, the tunnel between UPF1 and UPF2 is used as the target tunnel, and UPF3 only needs to To receive the tunnel information corresponding to the associated tunnel endpoint UPF1. Optionally, UPF3 may also receive tunnel information corresponding to UPF2, and allocate a Tunnel Endpoint for UPF2 as a forwarding tunnel for buffering DL data from UPF2. It can be understood that the same process is performed for sending tunnel information with the tunnel endpoint PSA at the other end, which will not be repeated here.

Optionally, the method for sending tunnel information provided by the embodiments of the present disclosure is applied to the N3 interface, and the data transmission links are: RAN, PSA1, and DN in sequence. In the case where PSA1 needs to be replaced with PSA2, the target tunnel is the tunnel between RAN and PSA1, and PSA2 only needs to receive AN Tunnel Info corresponding to the associated tunnel endpoint RAN. Optionally, PSA2 may also receive tunnel information corresponding to PSA1, and assign Tunnel Endpoint to PSA1 as a forwarding tunnel for buffering DL data from PSA1.

As for the insertion position of the UPF, the above cases are exemplary, and other insertion positions or manners known to those skilled in the art that can implement the present solution can be applied here, which is not limited thereto.

The relevant information also includes an address and/or a session identifier corresponding to an associated tunnel endpoint related to the target tunnel, and the session identifier is used to distinguish the session to which the tunnel information belongs;

The method also includes:

Referring to FIG. 7, the steps of modifying the GTP-U tunnel based on the user plane message provided by the embodiment of the present disclosure are as follows:

1. The SMF sends an N4 Session Establishment Request Message (N4 Session Establishment Request Message) to the inserted tunnel first endpoint UPF2. The request message contains the structured control information PDR and FAR that define the required behavior of UPF2, the N4 Session ID used to identify the N4 session context, the tunnel information of the tunnel peer, the address and session ID of UPF1, and the address and session ID of UPF3.

2. After receiving the message, UPF2 stores the tunnel information of the opposite end of the tunnel, and distributes the local uplink tunnel information (UL Tunnel Info) and downlink tunnel information (DL Tunnel Info) for the session.

3. UPF2 sends the allocated uplink tunnel information to the tunnel peer UPF3 through a user plane message, Send the allocated downlink tunnel information to the tunnel peer UPF1.

4. The inserted UPF sends an N4 session establishment response message (N4 Session Establishment Response Message) to the SMF.

Optionally, the reliability guarantee of the user plane message can be resent by setting a timer overtime, and the underlying protocol can use TCP/IP and other methods.

The user plane message used to exchange tunnel information can be a GTP-U signaling message, a UPF service based on a service interface, or a newly defined message message used for tunnel information exchange. For related introductions, refer to the above, and will not be repeated here.

Optionally, the method for sending tunnel information provided in this embodiment of the present disclosure may be applied to the N3 interface and/or the N9 interface. For the case of being applied to the N9 interface, refer to the introduction in FIG. 6 and FIG. 7 , and details will not be repeated here. For the case applied to the N3 interface, refer to Figure 6 and Figure 7, the UPF connected to the N3 interface can be used as the first endpoint of the tunnel, and the RAN or AN can be used as the second endpoint of the tunnel. After the UPF connected to the N3 interface distributes the uplink tunnel information, the uplink tunnel information is sent to the RAN or AN at the opposite end of the tunnel through a user plane message; the RAN or AN connected to the N3 interface can also be used as the first endpoint of the tunnel, and the UPF connected to the N3 interface can be used as the second endpoint of the tunnel. After that, the AN Tunnel Info is sent to the UPF at the opposite end of the tunnel through a user plane message.

Referring to FIG. 8, FIG. 8 is a second schematic flow diagram of a method for sending tunnel information provided by an embodiment of the present disclosure. This method can be applied to a network function entity, and the method includes:

Step 810, sending the second session identifier and/or the address of the second end point of the tunnel to the first end point of the tunnel;

Specifically, the network function entity NF refers to the network function entity related to the GTP-U tunnel, such as SMF, the first end point of the tunnel refers to the receiving end of the GTP-U tunnel, and the second end point of the tunnel refers to the sending end of the GTP-U tunnel. In the case of a message sent by a peer, the network function entity stores the address of the second end point of the tunnel. For the introduction of the second session identifier and the address of the second end point of the tunnel, refer to the introduction in FIG. 5 , which will not be repeated here.

In the method for sending tunnel information provided by the embodiments of the present disclosure, the network function entity sends the address of the second end point of the tunnel and/or the second session ID to the first end point of the tunnel, so that the first end point of the tunnel can send a user plane message carrying tunnel information to the second end point of the tunnel, and the second end point of the tunnel can distinguish the session to which the tunnel information belongs based on the second session ID, so that both ends of the GTP-U tunnel can exchange tunnel information through user plane messages, shorten the time for establishing or modifying the tunnel, and reduce the processing overhead of the control plane function by reducing the number of session messages executed by the network function entity, thereby improving the performance of the tunnel. the efficiency of tunnel message exchange,

Optionally, the method also includes any or a combination of the following:

receiving the tunnel information sent by the first endpoint of the tunnel;

Referring to FIG. 7, UPF1 is used as the first end point of the tunnel, and UPF3 is used as the second end point of the tunnel. After UPF1 allocates tunnel information to UPF3, it sends the tunnel information to the network function entity, and the network function entity receives the tunnel information sent by UPF1. The network function entity stores tunnel information corresponding to UPF1 and tunnel information corresponding to UPF3. When a tunnel modification occurs in the GTP-U tunnel between UPF1 and UPF3, that is, when a new tunnel endpoint UPF2 is inserted between UPF1 and UPF3, first related information and second related information are sent to UPF2, the first related information includes tunnel information corresponding to UPF1, and the second related information includes tunnel information corresponding to UPF3. The first related information and the second related information may be used for sending the downlink tunnel information to UPF1 through a user plane message, and sending the uplink tunnel information to UPF3 after UPF2 allocates uplink tunnel information and downlink tunnel information.

Optionally, the first related information further includes an address corresponding to the first endpoint of the tunnel and/or a first session identifier, the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first endpoint of the tunnel;

The second related information further includes an address corresponding to the second endpoint of the tunnel and/or the second Two session identifiers.

Optionally, the second session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second end point of the tunnel; or

The first session identifier includes:

For the introduction of network function entity identification and N4 Session ID, as well as the introduction of SUPI and PDU Session ID, refer to the introduction in Figure 5, and will not repeat them here. Exemplarily, with reference to Figure 7, a first N4 session is established between the SMF and UPF1, and the SMF allocates an N4 Session ID corresponding to the UPF1 for the first N4 session; a second N4 session is established between the SMF and UPF3, and the SMF allocates the N4 Session ID corresponding to the UPF3 for the second N4 session. The first session identifier can be the N4 Session ID corresponding to the SMF ID and UPF1, or it can be the SUPI and PDU Session ID, etc. The second session ID can be SMF ID and N4 Session ID corresponding to UPF3, or SUPI and PDU Session ID, etc.

In the method for sending tunnel information provided by the embodiments of the present disclosure, the network functional entity sends the first relevant information and the second relevant information to the newly inserted tunnel endpoint, so that the newly inserted tunnel endpoint can send the user plane message carrying the tunnel information to the tunnel peer endpoint, which realizes the exchange of tunnel information between the two ends of the GTP-U tunnel through the user plane message, shortens the time for establishing or modifying the tunnel, and reduces the processing overhead of the control plane function by reducing the number of session messages executed by the network functional entity, thereby improving the efficiency of tunnel message exchange.

Referring to FIG. 9, FIG. 9 is the third schematic flow diagram of the tunnel information sending method provided by the embodiment of the present disclosure, which can be applied to the modification of the GTP-U tunnel in the PDU session establishment process. The tunnel information sending method provided by the embodiment of the present disclosure includes:

If the PDU session establishment request is "initial request", SMF sends N4 Session Establishment Request to each selected UPF, otherwise sends N4 Session Modification Request. Wherein, before the establishment of the N4 session, the SMF first allocates the N4 Session ID for the N4 session. The request contains structured control information such as PDR and FAR defining the required behavior of the UPF, the N4 Session ID used to identify the N4 session context, and the IP address and session ID of another UPF. The session ID can be SMF ID and N4 Session ID, or SUPI and PDU Session ID, etc.

Each UPF acts as the first endpoint of the tunnel to perform the required behavior and distribute the required Tunnel Info. Then, UPF constructs GTP-U signaling, the message type is the newly defined "Tunnel Info Signal", and the IE is Tunnel Endpoint Identifier Data I, GTP-U Peer Address and the newly defined GTP-U Peer Session Identifier, which respectively represent the allocated TEID, allocated IP address, and peer session identifier (including UL/DL flags). The destination IP address of the GTP-U signaling message is the IP address of the opposite end of the tunnel (that is, the second end point of the tunnel), and the destination port number is the default port 2152.

The UPF at the first end point of the tunnel sends out the constructed GTP-U signaling message.

The UPF at the first end point of the tunnel sends an N4 session establishment or modification response message to the SMF, and the response message carries CN Tunnel Info.

Optionally, the N3 interface can also exchange tunnel messages based on user plane messages. The UPF sends UL Tunnel Info to (R)AN through user plane messages, and the (R)AN side sends UL Tunnel Info to UPF AN Tunnel Info through user plane messages, so that the UL link data transmission time can be advanced.

Optionally, the UPF at the first end point of the tunnel provides the Tunnel Info to the second end point of the tunnel at the opposite end of the tunnel through the Notify operation of Nupf_EventExposure.

Referring to FIG. 10, FIG. 10 is the fourth schematic flow diagram of the tunnel information sending method provided by the embodiment of the present disclosure, which can be applied to the service request process. The tunnel information sending method provided by the embodiment of the present disclosure includes:

If the CN Tunnel Info of UPF (PSA) changes, SMF sends N4 Session Modification Request message to UPF (PSA). If the SMF removes the old I-UPF without replacing it with a new I-UPF, and the request also carries the IP address and session ID of the old UPF, the SMF requests the UPF (PSA) to allocate a second tunnel endpoint as a forwarding tunnel for buffering DL data from the old UPF.

After the PSA allocates and forwards the tunnel DL Tunnel Info, it constructs a GTP-U signaling message, message type IE is the newly defined "Tunnel Info Signal", and IE is Tunnel Endpoint Identifier Data I, GTP-U Peer Address and newly defined GTP-U Peer Session Identifier, which respectively represent the allocated TEID, allocated IP address, and peer session identifier (DL flag). The destination IP address of the GTP-U signaling message is the IP address of the old UPF, and the destination port number is the default port 2152.

UPF (PSA) responds and provides new CN Tunnel Info to SMF.

If the SMF chooses to insert a new UPF as the intermediate UPF (I-UPF) of the PDU session, it sends an N4 Session Establishment Request message to the new I-UPF, requesting the allocation of Tunnel Info, and carrying the CN Tunnel Info of the PSA, adding the address and session identification information of the PSA. If the SMF selects a new UPF to replace the old I-UPF, the SMF may also request the new UPF to allocate a second tunnel endpoint as a forwarding tunnel for DL data buffered from the old I-UPF. Therefore, the address and session identification information of the old I-UPF also needs to be carried in the N4 session establishment request.

The new I-UPF allocates Tunnel Info, constructs the GTP-U signaling message sent to the PSA and the GTP-U signaling message sent to the old I-UPF respectively, and sends the constructed GTP-U signaling message. The new I-UPF responds to the SMF and provides the Tunnel Info requested by the SMF.

Optionally, UPF provides Tunnel Info to the tunnel peer through the Notify operation of Nupf_EventExposure.

Optionally, when the GTP-U tunnel is established, if a certain GTP-U entity (UPF) fails to serve, it will return a service denial message to the SMF. For this situation, the processing method is similar to the GTP-U tunnel modification.

When the SMF receives a denial of service message returned by the UPF. Then re-select a new UPF, send N4 Session Establishment Request message, and the request carries the address and session identifier of the UPF at the opposite end of the tunnel.

After receiving the request, the new UPF allocates local UL/DL Tunnel Info, constructs a user plane message, and sends the Tunnel Info to the tunnel peer.

The new UPF replies the N4 Session Establishment Response message to the SMF.

The tunnel information sending method provided by the embodiments of the present disclosure shortens the time for tunnel establishment or modification, and reduces the processing overhead of the control plane function by exchanging tunnel information through user plane messages. Taking the session management function entity SMF as an example, it reduces the number of SMFs performing N4 Session Modification The number of Request/Response, thus improving the efficiency of tunnel message exchange.

Referring to FIG. 11 , FIG. 11 is a schematic structural diagram of a tunnel first endpoint device provided by an embodiment of the present disclosure. The tunnel first endpoint device includes a transceiver 1100, a processor 1110, and a memory 1120, where:

The memory 1120 is used for storing computer programs; the transceiver 1100 is used for receiving and sending data under the control of the processor 1110 .

Wherein, in FIG. 11 , the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by the processor 1110 and various circuits of the memory represented by the memory 1120 are linked together. The bus architecture can also link together various other circuits such as peripherals, voltage regulators, and power management circuits, etc., which are well known in the art and therefore will not be further described herein. The bus interface provides the interface. The transceiver 1100 may be a plurality of elements, including a transmitter and a receiver, providing a unit for communicating with various other devices over transmission media, including wireless channels, wired channels, optical cables, and other transmission media. The processor 1110 is responsible for managing the bus architecture and general processing, and the memory 1120 can store data used by the processor 1110 when performing operations.

The processor 1110 may be a central processor (CPU), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field-Programmable Gate Array, FPGA) or a complex programmable logic device (Complex Programmable Logic Device, CPLD), and the processor may also adopt a multi-core architecture.

The processor 1110 calls the computer program stored in the memory 1120 to execute any of the methods provided in the embodiments of the present disclosure according to the obtained executable instructions, for example: based on the address of the second tunnel endpoint, sending a first user plane message to the tunnel second endpoint, where the first user plane message includes tunnel information corresponding to the tunnel first endpoint.

Optionally, the first user plane message is any of the following:

User plane function UPF service based on service interface;

The first packet message used for tunnel information exchange.

Optionally, the GTP-U signaling message is any of the following:

Signaling messages of new message types;

Add a signaling message with a flag bit on the message type;

Signaling message of the new GTP-U extension header.

Optionally, the UPF service based on the service interface includes:

Optionally, the notifying the second endpoint of the tunnel through the Notify operation includes:

Optionally, before sending the first user plane message to the second end point of the tunnel, the operation further includes:

Optionally, the second session identifier includes:

Optionally, the operation further includes any or a combination of the following:

Optionally, the first session identifier includes:

Optionally, when the first end point of the tunnel is a newly inserted end point of the target tunnel, the operation further includes:

Optionally, the relevant information further includes an address and/or a session identifier corresponding to an associated tunnel endpoint related to the target tunnel, and the session identifier is used to distinguish the session to which the tunnel information belongs;

The method also includes:

Based on the address corresponding to each associated tunnel endpoint, send a user plane message to each associated tunnel endpoint, where the user plane message includes tunnel information corresponding to the first tunnel endpoint and a session identifier corresponding to the associated tunnel endpoint. Optionally, the operation is applied to the N3 interface and/or the N9 interface.

What needs to be explained here is that the above-mentioned device provided by the embodiment of the present disclosure can realize all the method steps realized by the above-mentioned method embodiment, and can achieve the same technical effect, and the same parts and beneficial effects in this embodiment as in the method embodiment will not be described in detail here.

Referring to FIG. 12 , FIG. 12 is a schematic structural diagram of a network function entity provided by an embodiment of the present disclosure. The network function entity includes a transceiver 1200, a processor 1210, and a memory 1220, where:

The memory 1220 is used for storing computer programs; the transceiver 1200 is used for receiving and sending data under the control of the processor 1210 .

Wherein, in FIG. 12 , the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by the processor 1210 and various circuits of the memory represented by the memory 1220 are linked together. The bus architecture can also link together various other circuits such as peripherals, voltage regulators, and power management circuits, etc., which are well known in the art and therefore will not be further described herein. The bus interface provides the interface. The transceiver 1200 may be a plurality of elements, including a transmitter and a receiver, providing a unit for communicating with various other devices over transmission media, including wireless channels, wired channels, optical cables, and other transmission media. The processor 1210 is responsible for managing the bus architecture and general processing, and the memory 1220 can store data used by the processor 1210 when performing operations.

The processor 1210 may be a central processing device (CPU), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA) or Complex Programmable Logic Device (Complex Programmable Logic Device, CPLD), the processor can also adopt a multi-core architecture.

The processor 1210 calls the computer program stored in the memory 1220 to execute any of the methods provided in the embodiments of the present disclosure according to the obtained executable instructions, for example: sending the second session identifier and/or the address of the second tunnel end point to the first end point of the tunnel;

receiving the tunnel information sent by the first endpoint of the tunnel;

Optionally, the second session identifier includes:

The first session identifier includes:

Referring to FIG. 13, FIG. 13 is one of the schematic structural diagrams of the tunnel information sending device provided by the embodiment of the present disclosure. The device can be applied to the first end point of the tunnel, and the device includes:

The first sending unit 1310 is configured to send a first user plane message to the second tunnel end point based on the address of the second tunnel end point, where the first user plane message includes tunnel information corresponding to the tunnel first end point.

Referring to FIG. 14, FIG. 14 is a second structural diagram of a tunnel information sending device provided by an embodiment of the present disclosure. This device can be applied to a network function entity, and the device includes:

The second sending unit 1410 is configured to send the second session identifier and/or the address of the second end point of the tunnel to the first end point of the tunnel;

It should be noted that the division of the units in the embodiment of the present disclosure is schematic, and is only a logical function division, and there may be another division manner in actual implementation. In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is realized in the form of a software function unit and sold as an independent product Or when used, it can be stored in a processor-readable storage medium. Based on such an understanding, the technical solution of the present disclosure may essentially or partly contribute to the related technology or all or part of the technical solution may be embodied in the form of a software product, the computer software product is stored in a storage medium, and includes several instructions to make a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) execute all or part of the steps of the method described in each embodiment of the present disclosure. The above-mentioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other various media that can store program codes.

On the other hand, an embodiment of the present disclosure further provides a processor-readable storage medium, where the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the methods provided in the foregoing embodiments, including:

The processor-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disk, hard disk, magnetic tape, magneto-optical disk (MO), etc.), optical storage (such as CD, DVD, BD, HVD, etc.), and semiconductor storage (such as ROM, EPROM, EEPROM, non-volatile memory (NAND FLASH), solid-state hard drive, etc.) Disk (SSD)) and so on.

Those skilled in the art should understand that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Accordingly, the present disclosure can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each procedure and/or block in the flowchart and/or block diagrams, and combinations of procedures and/or blocks in the flowchart and/or block diagrams can be implemented by computer-executable instructions. These computer-executable instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor or a processor of other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for realizing the functions specified in one or more processes of the flowchart and/or one or more blocks of the block diagram.

These processor-executable instructions may also be stored in a processor-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, such that the instructions stored in the processor-readable memory produce an article of manufacture comprising instruction means that implement the functions specified in one or more flows of the flowchart and/or one or more blocks of the block diagram.

These processor-executable instructions can also be loaded on a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate computer-implemented processing, so that the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in one or more processes of the flow chart and/or one or more blocks of the block diagram.

It is obvious that those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and equivalent technologies thereof, the present disclosure also intends to include these modifications and variations.

Claims

A method for sending tunnel information, wherein, applied to a first endpoint of a tunnel, the method includes:

Based on the address of the second end point of the tunnel, send a first user plane message to the second end point of the tunnel, where the first user plane message includes tunnel information corresponding to the first end point of the tunnel.
The method for sending tunnel information according to claim 1, wherein the first user plane message is any of the following:

General Packet Radio Service User Plane Tunneling Protocol GTP-U signaling message;

User plane function UPF service based on service interface;

The first packet message used for tunnel information exchange.
The method for sending tunnel information according to claim 2, wherein the GTP-U signaling message is any of the following:

Reserving signaling messages of unused message types;

Add a signaling message with a flag bit on the message type;

Signaling message of the new GTP-U extension header.
The tunnel information sending method according to claim 2, wherein the UPF service based on the service interface comprises:

After allocating the tunnel information, the first end point of the tunnel notifies the second end point of the tunnel through a Notify operation.
The method for sending tunnel information according to claim 4, wherein the notifying the second end point of the tunnel through the Notify operation includes:

In the case that the network function entity subscribes to the tunnel information through Subscribe, the second end point of the tunnel is notified through a Notify operation.
The method for sending tunnel information according to any one of claims 1 to 5, wherein the first user plane message further includes a second session identifier, the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.
The method for sending tunnel information according to claim 6, wherein, before sending the first user plane message to the second end point of the tunnel, the method further comprises:

Receive the address of the second end point of the tunnel and/or the second session identifier sent by the network function entity.
The method for sending tunnel information according to claim 6, wherein the second session identifier comprises:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
The method for sending tunnel information according to claim 6, wherein, in the case where the first end point of the tunnel is a newly inserted end point of the target tunnel, the method further comprises:

Receiving related information sent by the network function entity, where the related information includes tunnel information corresponding to one or more associated tunnel endpoints related to the target tunnel.
The method for sending tunnel information according to claim 9, wherein the relevant information further includes an address and/or a session identifier corresponding to an associated tunnel endpoint related to the target tunnel, and the session identifier is used to distinguish the session to which the tunnel information belongs;

The method also includes:

Based on the address corresponding to each associated tunnel endpoint, send a user plane message to each associated tunnel endpoint, where the user plane message includes tunnel information corresponding to the first tunnel endpoint and a session identifier corresponding to the associated tunnel endpoint.
The method for sending tunnel information according to any one of claims 1 to 5, wherein the method is applied to the N3 interface and/or the N9 interface.
A method for sending tunnel information, wherein, applied to a network function entity, the method includes:

sending the second session identifier and/or the address of the second end point of the tunnel to the first end point of the tunnel;

The address of the second end point of the tunnel is used by the first end point of the tunnel to send a user plane message to the second end point of the tunnel, where the user plane message includes tunnel information corresponding to the first end point of the tunnel; the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.
The method for sending tunnel information according to claim 12, wherein the method further Includes any or a combination of the following:

receiving the tunnel information sent by the first endpoint of the tunnel;

Sending first related information and second related information to a newly inserted tunnel endpoint; the first related information includes tunnel information corresponding to the first tunnel endpoint, and the second related information includes tunnel information corresponding to the tunnel second endpoint.
The tunnel information sending method according to claim 13, wherein,

The first related information also includes an address corresponding to the first endpoint of the tunnel and/or a first session identifier, the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first endpoint of the tunnel;

The second related information further includes an address corresponding to the second end point of the tunnel and/or the second session identifier.
The method for sending tunnel information according to claim 14, wherein the second session identifier comprises:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second end point of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID;

The first session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the first endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
A tunnel first endpoint device, including a memory, a transceiver, and a processor; wherein:

The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations:

Based on the address of the second end point of the tunnel, send a first user plane message to the second end point of the tunnel, where the first user plane message includes tunnel information corresponding to the first end point of the tunnel.
The tunnel first endpoint device according to claim 16, wherein the first user plane message is any of the following:

General Packet Radio Service User Plane Tunneling Protocol GTP-U signaling message;

User plane function UPF service based on service interface;

The first packet message used for tunnel information exchange.
The tunnel first endpoint device according to claim 17, wherein the GTP-U signaling message is any of the following:

Reserving signaling messages of unused message types;

Add a signaling message with a flag bit on the message type;

Signaling message of the new GTP-U extension header.
The tunnel first endpoint device according to claim 17, wherein the UPF service based on the service interface includes:

After allocating the tunnel information, the first end point of the tunnel notifies the second end point of the tunnel through a Notify operation.
The tunnel first endpoint device according to claim 19, wherein the notifying the tunnel second endpoint through the Notify operation includes:

In the case that the network function entity subscribes to the tunnel information through Subscribe, the second end point of the tunnel is notified through a Notify operation.
The tunnel first endpoint device according to any one of claims 16 to 20, wherein the first user plane message further includes a second session identifier, the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the tunnel second endpoint.
The tunnel first endpoint device according to claim 21, wherein before sending the first user plane message to the tunnel second endpoint, the operation further comprises:

Receive the address of the second end point of the tunnel and/or the second session identifier sent by the network function entity.
The tunnel first endpoint device according to claim 21, wherein the second session identifier comprises:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
The tunnel first endpoint device according to claim 21, wherein, in the tunnel In the case where the first endpoint is a newly inserted endpoint of the target tunnel, the operation further includes:

Receiving related information sent by the network function entity, where the related information includes tunnel information corresponding to one or more associated tunnel endpoints related to the target tunnel.
The tunnel first endpoint device according to claim 24, wherein the relevant information further includes an address and/or a session identifier corresponding to an associated tunnel endpoint related to the target tunnel, and the session identifier is used to distinguish the session to which the tunnel information belongs;

Said actions also include:

Based on the address corresponding to each associated tunnel endpoint, send a user plane message to each associated tunnel endpoint, where the user plane message includes tunnel information corresponding to the first tunnel endpoint and a session identifier corresponding to the associated tunnel endpoint.
The tunnel first endpoint device according to any one of claims 16 to 20, wherein the operation is applied to the N3 interface and/or the N9 interface.
A network functional entity, including a memory, a transceiver, and a processor; wherein:

The memory is used to store computer programs; the transceiver is used to send and receive data under the control of the processor; the processor is used to read the computer programs in the memory and perform the following operations:

sending the second session identifier and/or the address of the second end point of the tunnel to the first end point of the tunnel;

The address of the second end point of the tunnel is used by the first end point of the tunnel to send a user plane message to the second end point of the tunnel, where the user plane message includes tunnel information corresponding to the first end point of the tunnel; the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.
The network function entity according to claim 27, wherein the operation further comprises any of the following or a combination thereof:

receiving the tunnel information sent by the first endpoint of the tunnel;

Sending first related information and second related information to a newly inserted tunnel endpoint; the first related information includes tunnel information corresponding to the first tunnel endpoint, and the second related information includes tunnel information corresponding to the tunnel second endpoint.
The network function entity according to claim 28, wherein,

The first related information further includes an address corresponding to the first end point of the tunnel and/or a first A session identifier, the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first end point of the tunnel;

The second related information further includes an address corresponding to the second end point of the tunnel and/or the second session identifier.
The network function entity according to claim 29, wherein the second session identifier comprises:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second end point of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID;

The first session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the first endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
A tunnel information sending device, wherein, applied to the first end point of the tunnel, the device includes:

The first sending unit is configured to send a first user plane message to the second tunnel end point based on the address of the second tunnel end point, where the first user plane message includes tunnel information corresponding to the tunnel first end point.
The device for sending tunnel information according to claim 31, wherein the first user plane message is any of the following:

General Packet Radio Service User Plane Tunneling Protocol GTP-U signaling message;

User plane function UPF service based on service interface;

The first packet message used for tunnel information exchange.
The device for sending tunnel information according to claim 32, wherein the GTP-U signaling message is any of the following:

Reserving signaling messages of unused message types;

Add a signaling message with a flag bit on the message type;

Signaling message of the new GTP-U extension header.
The device for sending tunnel information according to claim 32, wherein the UPF service based on the service interface includes:

After allocating the tunnel information, the first end point of the tunnel notifies the second end point of the tunnel through a Notify operation.
The device for sending tunnel information according to claim 34, wherein the notifying the second end point of the tunnel through the Notify operation includes:

In the case that the network function entity subscribes to the tunnel information through Subscribe, the second end point of the tunnel is notified through a Notify operation.
The device for sending tunnel information according to any one of claims 31 to 35, wherein the first user plane message further includes a second session identifier, the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.
The device for sending tunnel information according to claim 36, wherein the device further comprises a first receiving unit, configured to:

Receive the address of the second end point of the tunnel and/or the second session identifier sent by the network function entity.
The device for sending tunnel information according to claim 36, wherein the second session identifier comprises:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
The device for sending tunnel information according to claim 36, wherein the first receiving unit of the device is also used for:

When the first end point of the tunnel is a newly inserted end point of the target tunnel, relevant information sent by the network function entity is received, where the relevant information includes tunnel information corresponding to one or more associated tunnel end points related to the target tunnel.
The device for sending tunnel information according to claim 39, wherein the first sending unit, in the case where the related information further includes addresses and/or session identifiers corresponding to associated tunnel endpoints related to the target tunnel, based on the address corresponding to each associated tunnel endpoint, sending a user plane message to each of the associated tunnel endpoints, where the user plane message includes tunnel information corresponding to the first tunnel endpoint and a session identifier corresponding to the associated tunnel endpoint;

The session identifier is used to distinguish the session to which the tunnel information belongs.
The device for sending tunnel information according to any one of claims 31 to 35, wherein the device is applied to an N3 interface and/or an N9 interface.
A device for sending tunnel information, wherein, applied to a network function entity, the device includes:

The second sending unit is configured to send the second session identifier and/or the address of the second tunnel end point to the first end point of the tunnel;

The address of the second end point of the tunnel is used by the first end point of the tunnel to send a user plane message to the second end point of the tunnel, where the user plane message includes tunnel information corresponding to the first end point of the tunnel; the second session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the second end point of the tunnel.
The device for sending tunnel information according to claim 42, wherein the device further comprises a second receiving unit configured to receive the tunnel information sent by the first end point of the tunnel; and/or,

The second sending unit is further configured to send first related information and second related information to the newly inserted tunnel end point; the first related information includes tunnel information corresponding to the first end point of the tunnel, and the second related information includes tunnel information corresponding to the second end point of the tunnel.
The device for sending tunnel information according to claim 43, wherein the first related information further includes an address corresponding to the first endpoint of the tunnel and/or a first session identifier, the first session identifier is used to distinguish the session to which the tunnel information belongs, and corresponds to the first endpoint of the tunnel;

The second related information further includes an address corresponding to the second end point of the tunnel and/or the second session identifier.
The device for sending tunnel information according to claim 44, wherein the second session identifier comprises:

Network function entity identifier and N4 session identifier N4 Session ID, the N4 Session ID corresponds to the second endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID;

The first session identifier includes:

A network function entity identifier and an N4 session identifier N4 Session ID, the N4 Session ID corresponding to the first endpoint of the tunnel; or

Permanent identity SUPI and protocol data unit session identifier PDU Session ID.
A processor-readable storage medium, wherein the processor-readable storage medium stores a computer program, and the computer program is used to enable the processor to execute the method for transmitting tunnel information according to any one of claims 1 to 11, or the method for transmitting tunnel information according to any one of claims 12 to 15.