Method and related device for implementing business continuity

Abstract

Embodiments of the present disclosure provide a method and related devices for implementing business continuity. The method includes: receiving a target relocation message carrying target data routing information, where the target data routing information includes a target data network access identifier and network address translation information, and the network address translation information includes a target user equipment network address, a first application server network address, and a second application server network address; generating a packet processing rule according to the target data routing information, which includes a network address translation rule, and the network address translation rule includes converting the destination address of the uplink packet sent by the target user equipment from the first application server network address to the second application server network address, and converting the source address of the downlink packet with the destination address being the target user equipment network address received from the second application server network address to the first application server network address; and sending the packet processing rule to the target network device.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular, to a method and apparatus for implementing service continuity, a user plane function network element, a user equipment, an electronic device, and a computer-readable storage medium. Background Art

[0002] Currently, a technical problem to be solved is: when a UE (User Equipment) moves, how to perform the migration of an AS (Application Server) to maintain service continuity; or, when the AS migrates while the UE does not move, how to maintain service continuity.

[0003] Therefore, a new method and apparatus for implementing service continuity, an electronic device, and a computer-readable storage medium are needed.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present disclosure. Summary of the Invention

[0005] Embodiments of the present disclosure provide a method and apparatus for implementing service continuity, a user plane function network element, a user equipment, an electronic device, and a computer-readable storage medium, which can maintain service continuity when the user equipment or the application server migrates.

[0006] Other features and advantages of the present disclosure will become apparent through the following detailed description, or will be partially learned through the practice of the present disclosure.

[0007] An embodiment of the present disclosure provides a method for implementing service continuity. The method includes: receiving a target relocation message, where the target relocation message carries target data routing information, and the target data routing information includes a target data network access identifier and network address translation information. The network address translation information includes a target user equipment network address, a first application server network address, and a second application server network address. The target user equipment corresponding to the target user equipment network address has established a target protocol data unit session with a target protocol data unit session anchor user plane function network element and communicates with a first application server corresponding to the first application server network address; generating a packet processing rule according to the target data routing information, where the packet processing rule includes a network address translation rule, and the network address translation rule includes converting the destination address of an uplink packet sent by the target user equipment from the first application server network address to the second application server network address, and converting the source address of a downlink packet received with the destination address being the target user equipment network address from the second application server network address to the first application server network address; sending the packet processing rule to a target network device, so that the target network device forwards the uplink packet sent by the target user equipment to a second application server corresponding to the second application server network address according to the packet processing rule, and forwards a downlink packet received with the destination address being the target user equipment network address and the source address being the second application server network address to the target user equipment.

[0008] An embodiment of the present disclosure provides a method for implementing service continuity. The method includes: receiving, by a target user plane function network element, a target N4 session request message sent by a session management function network element, where the target N4 session request message includes a packet processing rule, and the packet processing rule includes a network address translation rule; receiving, by the target user plane function network element, an uplink packet; if the target user plane function network element detects, according to the packet processing rule, that the source address of the uplink packet is the target user equipment network address and the destination address is the first application server network address, then converting the destination address of the uplink packet to the second application server network address according to the network address translation rule; forwarding, by the target user plane function network element, the uplink packet with the destination address converted to the second application server network address to a second application server corresponding to the second application server network address.

[0009] An embodiment of the present disclosure provides a device for implementing service continuity. The device includes: a relocation message receiving unit, configured to receive a target relocation message, where the target relocation message carries target data routing information, and the target data routing information includes a target data network access identifier and network address translation information, and the network address translation information includes a target user equipment network address, a first application server network address, and a second application server network address, wherein a target protocol data unit session has been established between the target user equipment corresponding to the target user equipment network address and a target protocol data unit session anchor user plane function network element, and communication is performed with a first application server corresponding to the first application server network address; a processing rule generating unit, configured to generate a data packet processing rule according to the target data routing information, where the data packet processing rule includes a network address translation rule, and the network address translation rule includes converting the destination address of an uplink data packet sent by the target user equipment from the first application server network address to the second application server network address, and converting the source address of a downlink data packet received with the destination address being the target user equipment network address from the second application server network address to the first application server network address; a processing rule sending unit, configured to send the data packet processing rule to a target network device, so that the target network device forwards an uplink data packet sent by the target user equipment to a second application server corresponding to the second application server network address according to the data packet processing rule, and forwards a downlink data packet received with the destination address being the target user equipment network address and the source address being the second application server network address to the target user equipment.

[0010] An embodiment of the present disclosure provides a user plane function network element, including: a session request message receiving unit, configured to receive a target N4 session request message sent by a session management function network element, where the target N4 session request message includes a data packet processing rule, and the data packet processing rule includes a network address translation rule; an uplink data packet receiving unit, configured to receive an uplink data packet; an uplink data packet detection and conversion unit, configured to, if it is detected according to the data packet processing rule that the source address of the uplink data packet is the target user equipment network address and the destination address is the first application server network address, convert the destination address of the uplink data packet to the second application server network address according to the network address translation rule; an uplink data packet forwarding unit, configured to forward the uplink data packet with the destination address converted to the second application server network address to a second application server corresponding to the second application server network address.

[0011] An embodiment of the present disclosure provides a user equipment, which includes: a unit session establishment unit for establishing a target protocol data unit session to a user plane function network element of a first protocol data unit session anchor point; an application server communication unit for communicating with a first application server corresponding to a first application server network address; an uplink data packet sending unit for sending an uplink data packet to a target network device, where the source address of the uplink data packet is the target network device network address and the destination address is the first application server network address, so that the target network device processes the uplink data packet according to a data packet processing rule, converts the destination address of the uplink data packet into a second application server network address, and forwards the uplink data packet with the destination address converted into the second application server network address to a second application server corresponding to the second application server network address.

[0012] An embodiment of the present disclosure provides a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the method for realizing service continuity as described in the above embodiment.

[0013] An embodiment of the present disclosure provides an electronic device, including: one or more processors; a storage device configured to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the method for realizing service continuity as described in the above embodiment.

[0014] In the technical solutions provided by some embodiments of the present disclosure, on the one hand, by using network address translation technology, it is possible to maintain service continuity when the application server migrates or when the location of the user equipment changes. The implementation is simple and easy to deploy. On the other hand, it is a new technical solution added to the related technical solutions, with little modification to the system, and it is easy to standardize and deploy on a large scale.

[0015] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. Description of the Drawings

[0016] The drawings here are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present disclosure, and are used together with the specification to explain the principles of the present disclosure. Obviously, the drawings in the following description are only some embodiments of the present disclosure, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts. In the drawings:

[0017] Figure 1 Shows a schematic diagram of an EC architecture in the related art;

[0018] Figure 2 Shows a schematic diagram of another EC architecture in the related art;

[0019] Figure 3 Shows a flowchart of the AF influencing data routing for a single UE request in the related art;

[0020] Figure 4 Shows a schematic diagram of the process of notifying user plane management events in the related art;

[0021] Figure 5 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure;

[0022] Figure 6 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0023] Figure 7 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0024] Figure 8 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0025] Figure 9 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0026] Figure 10 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0027] Figure 11 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0028] Figure 12 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0029] Figure 13 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0030] Figure 14 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0031] Figure 15 Schematically shows a schematic diagram of the process of a method for implementing service continuity according to an embodiment of the present disclosure;

[0032] Figure 16 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure;

[0033] Figure 17 Schematically shows a block diagram of an apparatus for implementing service continuity according to an embodiment of the present disclosure;

[0034] Figure 18 Schematically shows a block diagram of a user plane function network element according to an embodiment of the present disclosure;

[0035] Figure 19 Schematically shows a block diagram of a user equipment according to an embodiment of the present disclosure. Detailed implementation manners

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more complete and thorough, and will fully convey the concept of the example embodiments to those skilled in the art.

[0037] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present disclosure. However, those skilled in the art will recognize that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be employed. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the present disclosure.

[0038] The block diagrams shown in the drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0039] The flowcharts shown in the drawings are merely illustrative and do not necessarily include all the contents and operations / steps, nor are they necessarily executed in the described order. For example, some operations / steps can be decomposed, and some operations / steps can be combined or partially combined, so the actual execution order may be changed according to the actual situation.

[0040] In particular, according to an embodiment of the present disclosure, the processes described below with reference to the flowchart can be implemented as computer software programs. For example, an embodiment of the present disclosure includes a computer program product that includes a computer program carried on a computer-readable storage medium, and the computer program includes program code for performing the method shown in the flowchart.

[0041] It should be noted that the computer-readable storage medium shown in the present disclosure can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM (Erasable Programmable Read Only Memory)), or a flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present disclosure, the computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries the computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable storage medium other than the computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable storage medium can be transmitted by any appropriate medium, including but not limited to: wireless, wire, optical fiber, RF (Radio Frequency), etc., or any suitable combination of the above.

[0042] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of methods, apparatuses, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code, and the above-mentioned module, segment of a program, or part of code includes one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order from that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, as well as the combination of blocks in the block diagram or flowchart, may be implemented by a dedicated hardware-based system for performing the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0043] The units described in the embodiments of the present disclosure may be implemented in software or in hardware, and the described units may also be provided in a processor. Among them, the names of these units do not, in some cases, constitute a limitation on the unit itself.

[0044] As another aspect, the present application also provides a computer-readable storage medium, which may be included in the electronic device described in the above embodiments; or may exist separately without being assembled into the electronic device. The above computer-readable storage medium carries one or more programs, and when the one or more programs are executed by an electronic device, the electronic device is caused to implement the methods described in the following embodiments. For example, the electronic device may implement as Figure 5 or Figure 6 or Figure 7 or Figure 8 or Figure 9 or Figure 10 or Figure 11 or Figure 12 or Figure 13 or Figure 14 or Figure 15 the respective steps shown.

[0045] EC (Edge Computing) minimizes the communication latency between the UE and the AS by deploying the AS close to the UE. The 3GPP (3rd Generation Partnership Project) Release 17 protocol TR23.748 is conducting standardization research on EC.

[0046] It should be noted that although the EC architecture of TR23.748 is used as the baseline of its solution for illustration in the embodiments of the present disclosure, the present disclosure is not limited thereto. In other embodiments, it can also be extended to adapt to other EC architectures.

[0047] Among them, implementing the EC includes two basic architectures, respectively as Figure 1 and Figure 2 shown.

[0048] Figure 1 In, the UPF (User Plane Function) / PSA (PDU (Protocol Data Unit) Session Anchor) is deployed near the base station (AN (Access Network)), and at the same time, the EAS (Edge Application Server) is deployed in the DN (Data Network) connected to the PSA.

[0049] Figure 2 In, when the UPF / PSA1 is deployed at the central location, by deploying a UL CL (Uplink Classifier) / BP (Branching Point) at the near-base station AN, and then splitting out a UPF / PSA2 of the near-base station, the EAS is deployed in the same DN of the local access connected to the PSA2.

[0050] That is Figure 1 does not use the UL CL / BP to access the EAS, Figure 2 uses the UL CL / BP to access the EAS.

[0051] The above Figure 1 and Figure 2Among them, the full English name of NEF is Network Exposure Function, that is, network exposure function. Nnef refers to the Nnef message for obtaining the services provided by NEF. The full English name of PCF is Policy Control Function, that is, policy control function. Npcf refers to the Npcf message for obtaining the services provided by PCF. The full English name of AF is Application Function, that is, application function. Naf refers to the Naf message for obtaining the services provided by AF. The full English name of AMF is Access and Mobility Management Function, that is, access and mobility management function. Namf refers to the Namf message for obtaining the services provided by AMF. The full English name of SMF is Session Management Function, that is, session management function. Nsmf refers to the Nsmf message for obtaining the services provided by SMF. The UE and AMF interact through the N1 interface, the AMF and AN interact through the N2 interface, the SMF and UPF interact through the N4 interface, the AN and UPF interact through the N3 interface, the UPF and DN interact through the N6 interface, and the UPFs interact through the N9 interface.

[0052] TR23.748 identifies the following KI (Key Issue) that needs to be addressed: When the UE moves, how to perform the migration of EAS to maintain service continuity while achieving EC communication (such as with very little communication latency). Or, when the EAS migrates and the UE does not move, how to maintain service continuity while achieving EC communication (such as with very little communication latency).

[0053] Specifically, refer to the description in Section 5.2.1 of Section 5.2 "Key Issue #2: Edge relocation" of TR23.748:

[0054] "With edge computing being deployed for 5G systems, UE mobility and application server relocation need to be considered when designing solutions for optimal deployment of edge solutions. For example, as the UE moves across the 5G system, the UE location may change and require the network and the edge to deal with the change of UE location. 3GPP Rel-16 specifications already address some of these aspects and the key issue is to study potential improvements."

[0055] Clause 6.5.2 of TS 22.261 contains requirements that are related to this key issue. SA WG1 defined the term Service Hosting Environment that has been translated and broadened in SA WG2 work in the present TR to Edge Hosting Environment as the environment providing support required for Edge Application Server's execution. The requirements from SA WG1 are thus being interpreted as applying to the Edge Hosting Environment.

[0056] The following scenarios of UE mobility and application server relocation will be investigated:

[0057] - Change of the serving Edge Application Server with no change of DNAI. This includes:

[0058] - Change of the Edge Application Server e.g. due to the serving Edge Application Server becoming congested or being in outage condition. This assumes EAS IP (Internet Protocol) address change.

[0059] - Change of the DNAI depending on the location of the UE to better serve the UE. This may imply EAS IP address change but in some cases the old EAS may be kept as long as the UE transaction is not over.

[0060] The technical solution provided by the embodiments of the present disclosure can be used to solve the above KI problem. For this problem, some mechanisms have been defined in 3GPP protocols TS23.501 and TS23.502 (introduced in Figure 3 and Figure 4 below) to solve this KI. The solution provided by the embodiments of the present disclosure is to enhance the mechanisms defined in TS23.501 and TS23.502 so as to more effectively solve Edge Relocation.

[0061] Figure 3 The flowchart shows how the AF in the related art affects the data routing for a single UE request.

[0062] In section 5.6.7 of 3GPP protocol TS23.501, a detailed description of the function of AF influence on traffic routing (Application Function influence on traffic routing) is given, and a related parameter table is provided as shown in Table 1 below.

[0063] The flowcharts for different scenarios are given in Section 4.3.6 of 3GPP protocol TS23.502. Figure 3 It is the process of the AF transferring an AF request targeting an individual UE address to the relevant PCF (Transferring an AF request targeting an individual UE address to the relevant PCF).

[0064] Such as Figure 3 shown, it may include the following steps.

[0065] Step 1: If the AF sends an AF request through the NEF, the AF sends a Nnef_TrafficInfluence_Create / Update / Delete Request (Nnef_Data Influence_Create / Update / Delete Request) for the individual UE address to the NEF. This request corresponds to the AF request to influence the data routing for the individual UE address. When the NEF receives the AF request from the AF, the NEF ensures the necessary authorization control and maps the information provided by the AF to the information required by the 5G core network. The NEF responds to the AF.

[0066] Step 2: If the PCF address based on the local configuration is not available on the NEF, the AF / NEF uses the Nbsf_Management_Discovery service operation (providing at least the UE address) to find the address of the relevant PCF, otherwise skip Step 1. The AF / NEF finds the BSF (Binding Support Function) according to the local configuration or by using the NRF (NF Repository Function).

[0067] Step 3: The BSF provides the PCF address to the AF / NEF in the Nbsf_Management_Discovery response message.

[0068] Step 4: If Step 1 is executed, the NEF will call the Npcf_PolicyAuthorization service to the PCF to transfer the AF request. If the AF directly sends an AF request to the PCF, the AF calls the Npcf_PolicyAuthorization service and the PCF responds to the AF.

[0069] Step 5: The PCF updates the SMF with the corresponding new PCC (Policy Control and Charging) rules, and the PCF initiates the SM policy association modification procedure. When receiving the PCC rules from the PCF, the SMF can take appropriate actions to reconfigure the user plane of the PDU session when applicable, such as:

[0070] - Add, replace, or remove a UPF in the data path, such as acting as a UL CL, BP, and / or PDU session anchor.

[0071] - Allocate a new prefix for the UE.

[0072] - Update the UPF related to the target DNAI with new traffic steering rules.

[0073] From Figure 3 it can be learned that the AF can directly send the Npcf_PolicyAuthorization_Create / Update / Delete Request message to the PCF; or, the AF can also first send the Nnef_TrafficInfluence_Create / Update / Delete Request message to the NEF, and then send the Npcf_PolicyAuthorization_Create / Update / Delete Request message to the PCF through the NEF. The parameters of the AF influencing data routing provided by the AF to the NEF and the parameters of the AF influencing data routing provided by the AF / NEF to the PCF are given below.

[0074] Section 5.4.3.3.3 of 3GPP protocol TS29.522 gives the parameters of the Application Function influence on traffic routing provided by the AF to the NEF, as shown in Table 1 below:

[0075] Table 1

[0076]

[0077] In the above Table 1, N is a positive integer greater than or equal to 1.

[0078] Section 5.6.2.13 of 3GPP protocol TS29.514 gives the parameters of the Application Function influence on traffic routing provided by the AF / NEF to the PCF, as shown in Table 2 below.

[0079] Table 2

[0080]

[0081]

[0082] Section 5.6.7.1 in TS23.501 defines the parameters that AF provides to NEF and PCF and affect data routing, as shown in Table 3 below.

[0083] Table 3

[0084]

[0085]

[0086] The full English name of DNN in Table 3 is Data Network Name, which means data network name. The full English name of S-NSSAI is Single Network Slice Selection Assistance Information, which means single network slice selection assistance information. The full English name of GPSI is Generic Public Subscription Identifier, which means generic public subscription identifier.

[0087] The above Table 3 is the parameters defined in Section 5.6.7.1 of TS23.501. The above Table 1 and Table 2 are the detailed definitions of the above parameters, and they are consistent.

[0088] 3GPP protocol TS29.571 RouteToLocation (Routing to Location) corresponds to the Traffic Routing requirements in TS23.501 and TS23.502, as shown in Table 4 below.

[0089] Table 4

[0090] Attribute Name Data Type Description dnai Dnai Indicates the location where the application is applied routeInfo Routing Information Includes data routing information routeProfId String Indicates the routing profile Id

[0091] As can be learned from Table 4 above, for each DNAI, it includes N6 traffic routing information and a Routing Profile ID. Among them, the Routing Profile ID is just a String, and its corresponding N6 Traffic Routing function is said to be negotiated in advance between the operator and the AF and configured on the AF and the 5G network in the standard. That is to say, the N6 Traffic Routing function corresponding to the Routing Profile ID is not defined in the standard.

[0092] Section 5.4.4.16 in TS29.571 defines Route Information as shown in Table 5 below.

[0093] Table 5

[0094] Attribute Name Data Type Description ipv4Addr Ipv4Addr IPv4 address of the tunnel endpoint in the data network ipv6Addr Ipv6Addr IPv6 address of the tunnel endpoint in the data network portNumber Uinteger UDP port number of the tunnel endpoint in the data network

[0095] From the definition of the above Route Information, the related technologies only support routing technologies based on UDP (User Datagram Protocol) tunnels.

[0096] In section 4.3.6.3 of TS23.502, a schematic diagram of the process for the Notification of User Plane Management Events is given as Figure 4 shown.

[0097] As Figure 4 shown, it includes the following steps.

[0098] Step 1: The conditions for the AF notification have been met. The SMF sends the notification to the NF that subscribes to the SMF notification. The further processing of the SMF notification depends on the receiving NF, as shown in steps 2a and 2c.

[0099] Step 2a: If the AF requests early notification through the NEF, the SMF notifies the target DNAI of the PDU session to the NEF by invoking the Nsmf_EventExposure_Notify service operation.

[0100] Step 2b: When the NEF receives Nsmf_EventExposure_Notify, the NEF performs information mapping (e.g., mapping the AF service internal ID provided in the notification related ID to the AF service ID, SUPI (Subscription Permanent Identifier) to GPSI, etc.), and triggers an appropriate Nnef_TrafficInfluence_Notify (Nnef_Data Influence_Notify) message. In this case, Step 2c does not apply.

[0101] Step 2c: If the AF requests direct early notification, the SMF notifies the AF of the target DNAI of the PDU session by invoking the Nsmf_EventExposure_Notify service operation.

[0102] Step 2d: The AF responds to the Nnef_TrafficInfluence_Notify by immediately invoking the Nnef_TrafficInfluence_AppRelocationInfo (Nnef_Data Influence_Application Relocation Information) service operation or after completing any required application relocation in the target DNAI. The AF includes the N6 service routing details corresponding to the target DNAI. The AF can respond negatively, for example, if the AF determines that the application relocation cannot be completed successfully and / or on time.

[0103] Step 2e: When the NEF receives Nnef_TrafficInfluence_AppRelocationInfo, the NEF triggers a corresponding Nsmf_EventExposure_AppRelocationInfo (Nsmf_Event Exposure_Application Relocation Information) message.

[0104] Step 2f: The AF responds to the Nsmf_EventExposure_Notify by immediately invoking the Nsmf_EventExposure_AppRelocationInfo service operation or after completing any required application relocation in the target DNAI. The AF includes the N6 service routing details corresponding to the target DNAI. The AF can respond negatively, for example, if the AF determines that the application relocation cannot be completed successfully on time.

[0105] Step 3: The SMF forces a change in the DNAI or adds, changes, or deletes a UPF.

[0106] If runtime coordination between the 5G core network and the AF is enabled based on local configuration, the SMF may wait for a response from the AF to the early notification according to the indication of "AF expected confirmation" included in the AF subscription to SMF events before this step. The SMF will not execute this step until a positive response is received from the AF.

[0107] Step 4a: If the AF requests late notification via the NEF, the SMF notifies the target DNAI of the PDU session to the NEF by invoking the Nsmf_EventExposure_Notify service operation.

[0108] If runtime coordination between the 5G core network and the AF is enabled based on local configuration, the SMF may send a late notification and wait for a positive response from the AF before activating a new uplink path according to the indication of "AF response" included in the AF subscription to SMF events.

[0109] Step 4b: When the NEF receives Nsmf_EventExposure_Notify, the NEF performs information mapping (such as mapping the AF service internal ID provided in the notification correlation ID to the AF service ID, SUPI to GPSI, etc.) and triggers an appropriate Nnef_EventExposure_Notify message. In this case, Step 4c does not apply.

[0110] Step 4c: If the AF requests direct late notification, the SMF notifies the target DNAI of the PDU session to the AF by invoking the Nsmf_EventExposure_Notify service operation.

[0111] Step 4d: The AF responds to Nnef_TrafficInfluence_Notify by immediately invoking the Nnef_TrafficInfluence_AppRelocationInfo service operation or after completing any required application relocation in the target DNAI. The AF includes the N6 service routing details corresponding to the target DNAI. The AF may respond negatively, for example, if the AF determines that the application relocation cannot be successfully completed on time.

[0112] Step 4e: When the NEF receives Nnef_TrafficInfluence_AppRelocationInfo, the NEF triggers the corresponding Nsmf_EventExposure_AppRelocationInfo message.

[0113] Step 4f. AF responds to Nsmf_EventExposure_Notify by immediately invoking the Nsmf_EventExposure_AppRelocationInfo service operation or after completing any required application relocation in the target DNAI. The AF includes N6 service routing details corresponding to the target DNAI. The AF may answer negatively, for example, if the AF determines that the application relocation cannot be successfully completed on time.

[0114] One item included in the KI mentioned above is: Change of the DNAI depending on the location of the UE to better serve the UE. This may imply EAS IP address change but in some cases the old EAS may be kept as long as the UE transaction is not over. This function can also be solved by applying the function defined in Section 4.3.6.3 of TS23.502.

[0115] As Figure 4 shown, this Notification has two scenarios, one is Early Notification and the other is Late Notification.

[0116] However, as mentioned above, the related technology only supports the routing technology based on the UDP (User Datagram Protocol) Tunnel.

[0117] The Event Notification of SMF is defined in 3GPP protocol TS29.508, and Tables 6, 7 and 8 can be referred to.

[0118] Table 6. Definition of Type Event Notification

[0119]

[0120]

[0121]

[0122]

[0123] Table 7, Definition of NsmfEventExposureNotification Type

[0124]

[0125] Table 8, Smf Event Enumeration

[0126] Enumeration Value Description AC_TY_CH Access Type Change UP_PATH_CH UP Path Change PDU_SES_REL PDU Session Release PLMN_CH PLMN Change UE_IP_CH UE IP address change DDDS Downlink data delivery status COMM_FAIL Communication failure PDU_SES_EST PDU Session Establishment QFI_ALLOC QFI allocation QOS_MON QoS Monitoring

[0127] As can be seen from the above Tables 6 - 8, in the message of NsmfEventExposureNotification (Nsmf Event Exposure Notification) provided by the SMF to the AF / NEF due to user plane path modification, there is one or more EventNotifications. Each EventNotification respectively describes a Notification event (that is, a report can contain reports of multiple events). One EventNotification contains some parameters, as shown in Table 6, including:

[0128] SUPI + GPSI;

[0129] Source DNAI;

[0130] Target DNAI;

[0131] DNAI Change Type;

[0132] Source UE IP address;

[0133] Target UE IP address;

[0134] Source N6 Traffic Routing information;

[0135] Target N6 Traffic Routing information.

[0136] The parameters of the Notification affecting data routing provided by the NEF to the AF as defined in TS29.522 are shown in the following Tables 9 and 10.

[0137] Table 9, Definition of Type EventNotification

[0138]

[0139]

[0140] Table 10, DnaiChangeType Enumeration

[0141]

[0142] As can be seen from Tables 9 and 10 above, the parameters included in the EventNotification message provided by the NEF to the AF due to the modification of the user plane path are almost the same as the parameters provided by the SMF (see Tables 6-8), except that the SUPI is not included. Generally, the SUPI is not allowed to be provided to the AF.

[0143] Table 10 gives several possible values of DnaiChangeType, which can only take EARLY or LATE during EventNotification, but the AF can subscribe to both simultaneously, that is, the SMF needs to report in both the Early and Late stages.

[0144] It should be noted that the technical solution proposed in the embodiments of the present disclosure can not only solve the KI#2 problem of EC, but also solve the problems of non-EC. Therefore, without special explanation later, the KI#2 problem of EC will not be specifically referred to, and the problem will be generalized, that is, the (E)AS mentioned later can be either EAS or AS.

[0145] From the definition of the foregoing RouteInformaiton, the related technologies only support the routing technology based on UDP tunnels. The embodiments of the present disclosure propose a new routing technology using reverse NAT (Network Address Translation) technology, which does not use tunnels and can solve the following technical problems:

[0146] Problem 1: When the (E)AS migrates and the UE does not move, achieve EC communication while maintaining service continuity (such as little communication delay).

[0147] The embodiments of the present disclosure propose that before or after the (E)AS migrates, the (E)AS notifies the AF, and the AF sends parameters such as the target DNAI of the (E)AS migration and the supported N6 routing method and parameters (parameters for NAT conversion) to the 5G network. The 5G network then performs data re-routing of the UE according to these parameters (including NAT, and inserting or modifying UL CL / BP).

[0148] Problem 2: When the UE moves, how to perform the migration of the (E)AS to maintain service continuity while achieving EC communication (such as little communication delay).

[0149] In an embodiment of the present disclosure, before or after the user plane is modified when the UE moves, the SMF notifies the AF (either through the NEF or directly to the AF): the list of target DNAIs supported after the UE moves, the supported N6 routing methods and parameters (parameters for NAT conversion), and other parameters. The AF determines to perform the migration of the (E)AS, and returns the selected parameters for the (E)AS migration (such as N6 routing methods and parameters) to the 5G network. The 5G network then performs data rerouting for the UE based on these parameters (including NAT, and inserting or modifying UL CL / BP).

[0150] The following combines Figure 5 - 16 embodiments to illustrate the method provided by the embodiments of the present disclosure by way of example.

[0151] Figure 5 A flowchart of a method for implementing service continuity according to an embodiment of the present disclosure is schematically shown. Figure 5 The method provided by the embodiment may be executed by the SMF, but the present disclosure is not limited thereto. As Figure 5 shown, the method provided by the embodiments of the present disclosure may include the following steps.

[0152] In step S510, a target relocation message is received. The target relocation message may carry target data routing information, and the target data routing information may include a target data network access identifier and network address translation information. The network address translation information may include a target user equipment network address, a first application server network address, and a second application server network address. Among them, the target user equipment corresponding to the target user equipment network address has established a target protocol data unit session to the user plane function network element of the first protocol data unit session anchor point and communicates with the first application server corresponding to the first application server network address.

[0153] In an exemplary embodiment, before receiving the target relocation message, the first application server has been migrated to the second application server through the application function network element.

[0154] In an exemplary embodiment, the target relocation message may include a session management policy control update notification message. Among them, receiving the target relocation message may include: receiving the session management policy control update notification message from the target policy control function network element. The session management policy control update notification message may include a source data network access identifier corresponding to the user plane function network element of the first protocol data unit session anchor point, the target data network access identifier, and the target data routing information.

[0155] In an exemplary embodiment, the session management policy control update notification message may be generated by the target policy control function network element based on a policy authorization request message received from the target network exposure function network element. The policy authorization request message includes the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information. Among them, the policy authorization request message may be generated by the target network exposure function network element based on an impact data routing request message received from the application function network element. The impact data routing request message may include the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

[0156] In an exemplary embodiment, the session management policy control update notification message may be generated by the target policy control function network element based on an impact data routing request message received from the application function network element. The impact data routing request message may include the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

[0157] In an exemplary embodiment, the target relocation message includes an event exposure application relocation information message. Wherein, receiving the target relocation message may include: receiving the event exposure application relocation information message from the application function network element, and the event exposure application relocation information message includes the target data routing information.

[0158] In an exemplary embodiment, before receiving the target relocation message, the method may further include: receiving an early event subscription message from the application function network element; determining to modify the protocol data unit session anchor user plane function network element; according to the determination of the modification of the protocol data unit session anchor user plane function network element, transmitting an early event notification message to the application function network element. The early event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function network element.

[0159] In an exemplary embodiment, the method may further include: the application function network element triggers, according to the early event notification message, the migration of the first application server from the source data network access identifier to the target data network access identifier to become the second application server.

[0160] In step S520, a packet processing rule is generated according to the target data routing information. The packet processing rule may include a network address translation rule. The network address translation rule may include translating the destination address of the uplink packet sent by the target user equipment from the first application server network address to the second application server network address, and translating the source address of the downlink packet received with the destination address being the target user equipment network address from the second application server network address to the first application server network address.

[0161] In an exemplary embodiment, if the target data routing information further includes a first port number of the first application server and a second port number of the second application server, the network address translation rule may further include translating the destination port number of the uplink packet from the first port number to the second port number, and translating the source port number of the downlink packet from the second port number to the first port number.

[0162] In step S530, the packet processing rule is sent to the target network device, so that the target network device forwards the uplink packet sent by the target user equipment to the second application server corresponding to the second application server network address according to the packet processing rule, and forwards the downlink packet received with the destination address being the target user equipment network address and the source address being the second application server network address to the target user equipment.

[0163] In an exemplary embodiment, if the target data network access identifier matches the source data network access identifier, the target network device may include the first protocol data unit session anchor user plane function network element. Among them, sending the packet processing rule to the target network device may include: sending an N4 session modification request message to the first protocol data unit session anchor user plane function network element, and the N4 session modification request message includes the packet processing rule.

[0164] In an exemplary embodiment, the method may further include: receiving an N4 session modification response message replied by the first protocol data unit session anchor user plane function network element; returning a session management policy control update notification response message to the target policy control function network element, so that the target policy control function network element returns an impact data routing response message to the application function network element. After receiving the impact data routing response message, the application function network element triggers the completion of migrating the first application server to the second application server.

[0165] In an exemplary embodiment, if the target data network access identifier does not match the source data network access identifier supported by the first protocol data unit session anchor user plane function network element, the target network device may include a second protocol data unit session anchor user plane function network element and an uplink classifier user plane function network element. The packet processing rule may further include a packet forwarding rule, and the packet forwarding rule may include forwarding an uplink packet received with a source address of the target user equipment network address and a destination address of the first application server network address to the second protocol data unit session anchor user plane function network element. Among them, sending the packet processing rule to the target network device may include: sending the packet forwarding rule to the uplink classifier user plane function network element; sending the network address translation rule to the second protocol data unit session anchor user plane function network element.

[0166] In an exemplary embodiment, before sending the packet processing rule to the target network device, the method may further include: determining the second protocol data unit session anchor user plane function network element; determining the uplink classifier user plane function network element; updating the downlink user plane of the first protocol data unit session anchor user plane function network element; updating the downlink user plane of the second protocol data unit session anchor user plane function network element.

[0167] In an exemplary embodiment, if the target data network access identifier does not match the source data network access identifier supported by the first protocol data unit session anchor user plane function network element, the target network device may include an uplink classifier user plane function network element. Among them, sending the packet processing rule to the target network device may include: sending the packet processing rule to the uplink classifier user plane function network element.

[0168] In an exemplary embodiment, the packet processing rule may further include a packet forwarding rule. Among them, after receiving the target relocation message, the method may further include: determining the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element; using the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network device. Among them, sending the packet processing rule to the target network device may include: sending the packet forwarding rule to the uplink classifier user plane function network element; sending the network address translation rule to the second protocol data unit session anchor user plane function network element.

[0169] In an exemplary embodiment, after receiving the target relocation message, the method may further include: determining the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element; using the uplink classifier user plane function network element as the target network device. Among them, sending the packet processing rule to the target network device may include: sending the packet processing rule to the uplink classifier user plane function network element.

[0170] In an exemplary embodiment, before receiving the target relocation message, the method may further include: receiving a late event subscription message from the application function network element; deciding to modify the protocol data unit session anchor user plane function network element; determining a second protocol data unit session anchor user plane function network element and an uplink classifier user plane function network element according to the decision to modify the protocol data unit session anchor user plane function network element; configuring the uplink classifier user plane function network element to forward the received uplink packet to the first protocol data unit session anchor user plane function network element; transmitting a late event notification message to the application function network element, where the late event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function network element.

[0171] In an exemplary embodiment, the method may further include: the application function network element triggers, according to the late event notification message, migrating the first application server from the source data network access identifier to the target data network access identifier to become the second application server.

[0172] In an exemplary embodiment, the packet processing rule may further include a packet forwarding rule. Among them, after receiving the target relocation message, the method may further include: using the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network device. Among them, sending the packet processing rule to the target network device may include: sending the packet forwarding rule to the uplink classifier user plane function network element; sending the network address translation rule to the second protocol data unit session anchor user plane function network element.

[0173] In an exemplary embodiment, after receiving the target relocation message, the method may further include: using the uplink classifier user plane function network element as the target network device. Among them, sending the packet processing rule to the target network device may include: sending the packet processing rule to the uplink classifier user plane function network element.

[0174] The method for implementing user service continuity provided by the embodiments of the present disclosure can, on the one hand, utilize network address translation technology to achieve business continuity when the application server migrates or when the location of the user device changes. The implementation is simple and easy to deploy. On the other hand, a new technical solution is added to the related technical solutions, with little modification to the system, making it easy to standardize and deploy on a large scale.

[0175] Figure 6 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. In Figure 6 the embodiment, (E)AS Relocation (relocation) is described under the condition that the source DNAI remains unchanged, that is, the source DANI and the target DNAI are the same. As Figure 6 shown, the method provided by the embodiments of the present disclosure may include the following steps.

[0176] Step 1.1: The target UE (target user equipment) establishes a target PDU Session (target protocol data unit session) to a UPF / PSA1 (first protocol data unit session anchor user plane function network element) through the SMF (session management network element), and assigns an IPv4 (Internet Protocol version 4) address or an IPv6 (Internet Protocol version 6) Prefix (prefix) to the target UE. In the following description, the IPv4 address and the IPv6 Prefix are also collectively referred to as the IP address, and the IP address of the target UE is called the target user equipment network address.

[0177] Step 1.2: The target UE establishes an IP connection with an (E)AS1 (first application server) through the assigned IP address to perform IP communication for business interaction.

[0178] Step 1.3: The AF decides to migrate the (E)AS1 to the (E)AS2 (second application server).

[0179] For example, migrate the virtual machine running (E)AS1 from one physical Server to another. Among them, the two physical Servers may be in the same Cloud Data Center or may not be in the same Cloud Data Center. When in the same Cloud Data Center, generally its corresponding DNAI remains unchanged, that is, the source DNAI corresponding to (E)AS1 is the same as the target DNAI corresponding to (E)AS2. When not in the same Cloud Data Center, its corresponding DNAI will change, that is, the source DNAI corresponding to (E)AS1 is different from the target DNAI corresponding to (E)AS2. Figure 6 In the embodiment, the example is given with the DNAI remaining unchanged.

[0180] Step 1.4: AF can directly send a message to the target PCF (target policy control function network element), or AF can first send a message to the target NEF (target network exposure function network element), and then the target NEF sends a message to the target PCF.

[0181] Figure 6 In the embodiment, an example is given with AF sending an Nnef_TrafficInfluenceCreate / UpdateRequest message (Nnef_data influence creation / update request message, referred to as the influence data routing request message) to the target NEF. In other embodiments, AF can also directly send an Nnef_TrafficInfluenceCreate / Update Request message to the target PCF.

[0182] If AF sends a TrafficInfluence-related message to the target NEF for the first time, it is an Nnef_TrafficInfluenceCreate Request message; if AF is not sending a TrafficInfluence-related message to the target NEF for the first time, it is an Nnef_TrafficInfluenceUpdate Request message.

[0183] Figure 6In the embodiment, the IPue included in the Nnef_TrafficInfluenceCreate / Update Request message is the UE IP address (i.e., the target user equipment network address) in steps 1.1 and 1.2. The (E)AS1 RelocationIndication is the (E)AS1 relocation indication information used to indicate that (E)AS1 is about to be migrated. The Source DNAI (source DNAI) and Target DNAI (target DNAI) are newly added parameters indicating that (E)AS1 will be migrated from the Source DNAI to the target DNAI. If the Source DNAI and the Target DNAI take the same value, it indicates that the DNAI has not actually changed. The Traffic Filter includes at least the network address (IP address) IPas1 of the first application server corresponding to (E)AS1, the target port number PORTas1 (the first port number of the first application server) corresponding to (E)AS1, and the transport layer protocol (such as UDP / TCP (Transmission Control Protocol)), and may also include the IP address of the target UE, i.e., IPue; and the target N6 Traffic Routing Information, i.e., the target data routing information.

[0184] Continue to refer to Figure 6 , the target N6 Traffic Routing Information may include the DNAI (here it refers to the target DNAI); the network address translation information, i.e., NAT, where NAT includes performing NAT conversion between (IPue, IPas1, (o (abbreviation of option, i.e., optional) PORTas1) and (IPue, IPas2, (o) PORTas2)), that is, NAT(between(IPue, IPas1, (o) PORTas1)and(IPue, IPas2, (o) PORTas2)). IPas2 represents the network address (IP address) of the second application server corresponding to (E)AS2, and PORTas2 represents the second port number of the second application server.

[0185] It should be noted that the Nnef_TrafficInfluenceCreate / Update Request message may include one or more N6 Traffic Routing Information. Figure 6In the embodiments, only the new N6 Traffic Routing Information using the NAT method proposed by the present disclosure is listed. This NAT converts an IP flow (uplink data packet) with a source address of IPue and a destination address of IPas1 into an IP flow with a source address of IPue and a target address of IPas2; and converts an IP flow (downlink data packet) with a source address of IPas2 and a destination address of IPue into an IP flow with a source address of IPas1 and a destination address of IPue. Optionally, when the PORT (port) parameter is included, the NAT converts an IP flow (uplink data packet) with a source address of IPue, a destination address of IPas1, and a destination port number of PORTas1 into an IP flow with a source address of IPue, a target address of IPas2, and a destination port number of PORTas2; and converts an IP flow (downlink data packet) with a source address of IPas2, a destination address of IPue, and a source port number of PORTas2 into an IP flow with a source address of IPas1, a destination address of IPue, and a source port number of PORTas1.

[0186] If the AF decides to send an Nnef_TrafficInfluenceCreate / Update Request message to the target NEF, the AF can query the internal configuration information according to the IPue in the Nnef_TrafficInfluenceCreate / Update Request message to obtain the target NEF ID (not defined by the standard), and then send the Nnef_TrafficInfluenceCreate / Update Request message to the target NEF corresponding to this target NEF ID.

[0187] Step 1.5: The target NEF sends an Npcf_PolicyAuthorization_Create / Update Request message (Npcf_Policy Authorization_Create / Update Request, that is, a policy authorization request message) to the target PCF according to the above parameters provided by the AF. If the message in Step 1.4 is an Nnef_TrafficInfluenceCreate Request message, then Step 1.5 is an Npcf_PolicyAuthorization_Create Request message; if the message in Step 1.4 is an Nnef_TrafficInfluenceUpdate Request message, then Step 1.5 is an Npcf_PolicyAuthorization_Update Request message.

[0188] Among them, the target NEF can map to obtain the SUPI, DNN, and S-NSSAI based on the above parameters provided by the AF. Among them, the IPue, Source DNAI, Target DNAI, Traffic Filter, and Target N6 Traffic Routing Information in the Npcf_PolicyAuthorization_Create / Update Request message are directly from the parameters in the Nnef_TrafficInfluenceCreate / Update Request message in step 1.4.

[0189] If the AF / target NEF sends an Npcf_PolicyAuthorization_Create / Update Request message to the target PCF, the AF / target NEF queries the BSF based on the IPue in the Npcf_PolicyAuthorization_Create / Update Request message to obtain the ID of the target PCF, and then sends an Npcf_PolicyAuthorization_Create / Update Request message to the PCF corresponding to the target PCF.

[0190] Step 1.6: The target PCF sends an Npcf_SMPolicyControl UpdateNotify message (Npcf_SM policy control update notification message, that is, session management policy control update notification message, the full English name of SM is Session Management) to the SMF, which contains some parameters provided in steps 1.4 / 1.5: IPue, Source DNAI, Target DNAI, Traffic Filter, Target N6 Traffic Routing Information.

[0191] Step 1.7: The SMF receives the Npcf_SMPolicyControl UpdateNotify message provided by the target PCF, and determines that the Target DNAI and the Source DNAI therein are the same. Therefore, the SMF decides not to change the PSA, that is, not to perform the UL CL insertion operation. At the same time, the SMF determines to perform the NAT operation according to the Target N6 Traffic Routing Information provided by the target PCF. Therefore, the SMF sends an N4 Session Command (session instruction) to the UPF / PSA1. In Step 1.1, the SMF has sent an N4 Session Establishment Request message (i.e., N4 session establishment request message) to the UPF / PSA1, and the UPF / PSA1 has returned an N4 Session Establishment Response message (i.e., N4 session establishment response message) to the SMF. Therefore, in Step 1.7, the SMF can send an N4 Session Modification Request message (i.e., N4 session modification request message) to the UPF / PSA1, and carry the packet processing rule in this N4 session modification request message.

[0192] After receiving the N4 Session Modification Request message, the UPF / PSA1 returns an N4 Session Modification Response message (i.e., N4 session modification response message) to the SMF to confirm that it has received the N4 Session Modification Request message.

[0193] The UPF / PSA1 can convert the detected IP flow (uplink data packet) with the source address of IPue and the destination address of IPas1 into an IP flow with the source address of IPue and the target address of IPas2 according to the data packet processing rule; and convert the detected IP flow (downlink data packet) with the source address of IPas2 and the destination address of IPue into an IP flow with the source address of IPas1 and the destination address of IPue. Optionally, when the PORT (port) parameter is included, the UPF / PSA1 can convert the detected IP flow (uplink data packet) with the source address of IPue, the destination address of IPas1, and the destination port number of PORTas1 into an IP flow with the source address of IPue, the target address of IPas2, and the destination port number of PORTas2; and convert the detected IP flow (downlink data packet) with the source address of IPas2, the destination address of IPue, and the source port number of PORTas2 into an IP flow with the source address of IPas1, the destination address of IPue, and the source port number of PORTas1.

[0194] Step 1.8: The SMF returns an Npcf_SMPolicyControl UpdateNotify Response message to the target PCF according to the received N4 Session Modification Response message sent by the UPF / PSA1.

[0195] Step 1.9: The target PCF returns an Npcf_PolicyAuthorization_Create / Update Response message to the target NEF according to the received Npcf_SMPolicyControl UpdateNotifyResponse message sent by the SMF.

[0196] Step 1.10: The target NEF returns an Nnef_TrafficInfluenceCreate / UpdateResponse message to the AF according to the received Npcf_PolicyAuthorization_Create / Update Response message sent by the target PCF.

[0197] Step 1.11: After receiving the Nnef_TrafficInfluenceCreate / Update Response message from the target NEF, if it is a Positive (affirmative) reply, the migration of (E)AS1 to (E)AS2 is completed.

[0198] Step 1.12. The uplink data packet sent by the target UE through the target PDU session established in Step 1.1, such as an uplink IP packet, arrives at the UPF / PSA1. If the UPF / PSA1 detects, according to the packet processing rules sent by the SMF in Step 1.7 above, that the source address of the received uplink IP packet is IPue, the destination address is IPas1, the source port number is PORTue (the port number of the target UE), the destination port number is PORTas1 (if the packet processing rules also include a first port number and a second port number), and the transport layer protocol is, for example, UDP / TCP, then it proceeds to Step 1.13.

[0199] Step 1.13. The UPF / PSA1 replaces the destination address IPas1 of the received uplink IP packet with IPas2 and replaces the destination port number PORTas1 with PORTas2 according to the packet processing rules sent by the SMF in Step 1.7 above (if PORT conversion is to be performed in the packet processing rules, it is similar in the following embodiments).

[0200] Step 1.14. The UPF / PSA1 sends the uplink IP packet (source address IPue, destination address IPas2, source port number PORTue, destination port number PORTas2, transport layer protocol (such as UDP / TCP)) after NAT conversion to the (E)AS2.

[0201] Step 1.15. The (E)AS2 receives the uplink IP packet, and the replied downlink IP packet (source address IPas2, destination address IPue, source port number PORTas2, destination port number PORTue, transport layer protocol (such as UDP / TCP)) arrives at the UPF / PSA1.

[0202] Step 1.16. The UPF / PSA1 detects, according to the packet processing rules sent by the SMF in Step 1.7, that the (source address IPas2, destination address IPue, source port number PORTas2, transport layer protocol (such as UDP / TCP)) of the received downlink IP packet matches the packet processing rules, then it replaces the destination address IPas2 of the received downlink IP packet with IPas1 and replaces the source port number PORTas2 with PORTas1 (if PORT conversion is to be performed in the packet processing rules, it is similar in the following embodiments).

[0203] Step 1.17. The UPF / PSA1 sends the downlink IP packet (source address IPas1, destination address IPue, source port number PORTas1, destination port number PORTue, transport layer protocol (such as UDP / TCP)) after NAT conversion to the target UE through the established target PDU session.

[0204] It should be noted that if the uplink data packet received by the UPF / PSA1 successor still matches the above data packet processing rules, the processing continues according to steps 1.13 and 1.14 above. If the downlink data packet received by the UPF / PSA1 successor still matches the above data packet processing rules, the processing continues according to steps 1.16 and 1.17 above. If the data packet processing rules include the PORT item, the conversion of PORT needs to be performed.

[0205] Figure 7 A schematic flowchart of a method for implementing service continuity according to an embodiment of the present disclosure is schematically shown. Figure 7 Steps 2.1-2.2 in the embodiment are similar to Figure 6 Steps 1.1-1.2 in the embodiment. Figure 7 The difference between the embodiment and Figure 6 the embodiment is that in step 2.3, (E)AS1 completes the migration to (E)AS2, so Figure 6 step 1.11 in the embodiment is no longer executed. Figure 7 Steps 2.4-2.10 in the embodiment are similar to Figure 6 Steps 1.4-1.10 in the embodiment, Figure 7 Steps 2.11-2.16 in the embodiment are similar to Figure 6 Steps 1.12-1.17 in the embodiment.

[0206] In the following embodiments, there may also be similar situations after and before the completion of the migration of (E)AS1 to (E)AS2.

[0207] Figure 8 A schematic flowchart of a method for implementing service continuity according to an embodiment of the present disclosure is schematically shown. Figure 8 The embodiment is (E)AS Relocation in the case of DNAI change, and it is determined that the UPF / PSA2 (the second protocol data unit session anchor user plane function network element) performs NAT conversion.

[0208] Figure 8 Steps 3.1-3.6 in the embodiment are similar to Figure 6 Steps 1.1-1.6 in the embodiment, except that the Target DNAI in the message sent by the AF is different from the Source DNAI. Figure 8 The difference between the embodiment and Figure 6 the embodiment is that it further includes the following steps.

[0209] Step 3.7: If the DNAI (target DNAI) in the target PCF's message received by the SMF, i.e., DNAI in NAT(between(IPue,IPas1,(o)PORTas1)and(IPue,IPas2,(o)PORTas2)) in target N6 Traffic Routing Information, does not match the DNAI (source DNAI) supported by the UPF / PSA1 of the current SMF, then the SMF determines and selects a UPF / PSA2 and a UPF / UL CL (User Plane Function for Uplink Classifier) that match the DNAI (target DNAI) provided by the AF. The SMF sends a message to the selected UPF / PSA2. For the detailed interaction process between the SMF and PSA2, see Step 2 in Section 4.3.5.4 (Addition of additional PDU Session Anchor and Branching Point or UL CL) of TS23.502.

[0210] Step 3.8: The SMF determines and selects a UPF / UL CL. For the detailed interaction process between the SMF and the UPF / UL CL, see Step 3 in Section 4.3.5.4 of TS23.502.

[0211] Step 3.9: The SMF sends a message to the UPF / PSA1 to cause the downlink user plane of the UPF / PSA1 to switch from the RAN (Radio AN) to the UPF / UL CL. For the detailed interaction process, see Step 4 in Section 4.3.5.4 of TS23.502.

[0212] Step 3.10: The SMF sends a message to the UPF / PSA2 to cause the downlink user plane of the UPF / PSA2 to be the UPF / UL CL. For the detailed interaction process, see Step 5 in Section 4.3.5.4 of TS23.502.

[0213] Step 3.11: The SMF generates a packet forwarding rule for sending packets to the UPF / UL CL based on the target N6 Traffic Routing Information (DNAI, NAT(between(IPue,IPas1,(o)PORTas1)and(IPue,IPas2,(o)PORTas2)) received in Step 3.7. According to this packet forwarding rule, the UPF / UL CL can forward the uplink packets with the source address of IPue, the destination address of IPas1, and optionally the destination port number of PORTas1 to the UPF / PSA2.

[0214] It should be noted that step 3.11 can also be executed in step 3.8. That is, when the SMF sends a message to the UPF / UL CL for the first time, the message sent is the N4 Session Establishment Request message, and the packet forwarding rule can be included in the N4 Session Establishment Request message and sent to the UPF / UL CL. The UPF / UL CL replies to the SMF with the N4 Session Establishment Response message to confirm the receipt of the N4 Session Establishment Request message. If the SMF is not sending a message to the UPF / UL CL for the first time, the message sent is the N4 Session Modification Request message, and the packet forwarding rule can be included in the N4 Session Modification Request message and sent to the UPF / UL CL. The UPF / UL CL replies to the SMF with the N4 Session Modification Response message to confirm the receipt of the N4 Session Modification Request message.

[0215] The above N4 Session Establishment Request message or N4 Session Modification Request message sent by the SMF to the UPF / UL CL and containing the packet forwarding rule is called the first N4 session request message.

[0216] Step 3.12: The SMF generates and sends a network address translation rule to the UPF / PSA2 according to the target N6 Traffic Routing Information (DNAI, NAT (between (IPue, IPas1, (o)PORTas1) and (IPue, IPas2, (o)PORTas2)) received in step 3.7, so that the UPF / PSA2 can perform the NAT operation.

[0217] It should be noted that step 3.12 can also be executed in step 3.10. That is, when the SMF sends a message to the UPF / PSA2 for the first time, the message sent is the N4 Session Establishment Request message, and the network address translation rule can be included in the N4 Session Establishment Request message and sent to the UPF / PSA2. The UPF / PSA2 replies to the SMF with an N4 Session Establishment Response message to confirm receipt of the N4 Session Establishment Request message. If the SMF is not sending a message to the UPF / PSA2 for the first time, the message sent is the N4 Session Modification Request message, and the network address translation rule can be included in the N4 Session Modification Request message and sent to the UPF / PSA2. The UPF / PSA2 replies to the SMF with an N4 Session Modification Response message to confirm receipt of the N4 Session Modification Request message.

[0218] The above-mentioned N4 Session Establishment Request message or N4 Session Modification Request message sent by the SMF to the UPF / PSA2 and containing the packet forwarding rule is called the second N4 session request message.

[0219] Step 3.13: The SMF sends a message to the RAN so that the uplink user plane of the RAN is updated to the UPF / UL CL. For the detailed interaction process, see step 6 in section 4.3.5.4 of TS23.502.

[0220] Figure 8 Steps 3.14 - 3.17 in the embodiment are similar to Figure 6 Steps 1.8 - 1.11 in the embodiment.

[0221] Step 3.18: The uplink data packet sent by the target UE, such as an uplink IP packet (source address IPue, destination address IPas, source port number PORTue, destination port number PORTas1, transport layer protocol (such as UDP / TCP)), arrives at the UPF / UL CL.

[0222] Step 3.19. The UPF / UL CL, according to the data packet forwarding rule sent by the SMF in Step 3.11, if it detects that the source address of the uplink IP packet is IPue, the destination address is IPas1, and the destination port number is PORTas1 (if the data packet forwarding rule also includes PORT-related parameters), then forwards the uplink IP packet that matches the data packet forwarding rule to the UPF / PSA2; otherwise, forwards the uplink IP packet that does not match the data packet forwarding rule to the UPF / PSA1.

[0223] Figure 8 Steps 3.20 - 3.25 in the embodiment are similar to Figure 6 Steps 1.13 - 1.17 in the embodiment, except that Figure 8 in the embodiment, the UPF / PSA2 performs the matching of the data packet processing rule and the NAT conversion, and the downlink data packet is sent from the UPF / PSA2 to the UPF / UL CL and then sent to the target UE.

[0224] It can be understood that Figure 8 in the embodiment, the UPF / UL CL needs to perform matching and steering operations on the uplink data packets; for the downlink data packets, no matching operation is performed, and the downlink data packets are directly sent to the RAN and then reach the target UE.

[0225] It should be noted that if the uplink data packets subsequently received by the UPF / PSA2 still match the above data packet processing rule, then continue to process according to Steps 3.20 and 3.21 above. If the downlink data packets subsequently received by the UPF / PSA2 still match the above data packet processing rule, then continue to process according to Steps 3.22 and 3.23 above. If the data packet processing rule includes a PORT item, then a PORT conversion needs to be performed.

[0226] Figure 9 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. Figure 9 The embodiment is similar to Figure 8 the embodiment, the difference is that in Step 4.3, the migration from (E)AS1 to (E)AS2 is completed, so Figure 8 Step 3.17 in the embodiment is no longer executed.

[0227] Figure 9 Steps 4.1 - 4.2 in the embodiment are similar to Figure 8 Steps 3.1 - 3.2 in the embodiment, Figure 9 Steps 4.4 - 4.16 in the embodiment are similar to Figure 8 Steps 3.4 - 3.16 in the embodiment, Figure 9 Steps 4.17 - 4.24 in the embodiment are similar to Figure 8Steps 3.18 - 3.25 in the embodiment are similar.

[0228] Figure 10 The flowchart schematically shows a method for implementing service continuity according to an embodiment of the present disclosure. Figure 10 The embodiment is similar to Figure 8 the embodiment, with the difference that Figure 10 in the embodiment, NAT conversion is performed by UPF / ULCL instead of UPF / PSA2.

[0229] Figure 8 In the embodiment, UPF / UL CL only performs matching steering in the data packet processing rules, and UPF / PSA2 performs NAT conversion. Figure 10 The embodiment is to Figure 8 change the NAT conversion in the embodiment from UPF / PSA2 to UPF / UL CL. Therefore, Figure 10 in the embodiment, UPF / UL CL has the function of steering the data after NAT conversion, while UPF / PSA2 no longer has special functions and is similar to the functions in the relevant standards.

[0230] Figure 10 Steps 5.1 - 5.10 in the embodiment are similar to Figure 8 Steps 3.1 - 3.10 in the embodiment, and the Target DNAI in the message sent by AF is different from the Source DNAI. Figure 8 Steps 3.11 and 3.12 in the embodiment are no longer executed.

[0231] Step 5.11, SMF generates and sends a data packet processing rule to UPF / UL CL according to the target N6 Traffic Routing Information (DNAI, NAT(between(IPue,IPas1,(o)PORTas1)and(IPue,IPas2,(o)PORTas2)) received in step 5.6, so that UPF / UL CL can perform NAT operations and send the converted uplink data packets to UPF / PSA2.

[0232] It should be noted that step 5.11 can also be executed in step 5.8. That is, when the SMF sends a message to the UPF / UL CL for the first time, the message sent is the N4 Session Establishment Request message, and the packet processing rule can be included in this N4 Session Establishment Request message and sent to the UPF / UL CL. The UPF / UL CL replies to the SMF with an N4 Session Establishment Response message to confirm receipt of this N4 Session Establishment Request message. If the SMF is not sending a message to the UPF / UL CL for the first time, the message sent is the N4 Session Modification Request message, and the packet processing rule can be included in this N4 Session Modification Request message and sent to the UPF / UL CL. The UPF / UL CL replies to the SMF with an N4 Session Modification Response message to confirm receipt of this N4 Session Modification Request message.

[0233] The above N4 Session Establishment Request message or N4 Session Modification Request message sent by the SMF to the UPF / UL CL and containing the packet processing rule is called the target N4 session request message.

[0234] Steps 5.12 - 5.17 are the same as Figure 8 Steps 3.13 - 3.18 in the embodiment.

[0235] Step 5.18, the UPF / UL CL, according to the packet processing rule sent by the SMF in step 5.11, detects that the source address of the received uplink packet is IPue, the destination address is IPas1, and the destination port number is PORTas (if the packet processing rule also includes PORTas)), then performs NAT conversion on the uplink packet that matches this packet processing rule (see Figure 6 Step 1.13 of the embodiment).

[0236] Step 5.19, the UPF / UL CL forwards the converted uplink packet to the UPF / PSA2. The UPF / UL CL forwards the uplink packets that do not match this packet processing rule to the UPF / PSA1.

[0237] Step 5.20, the UPF / PSA2 sends this uplink packet to the (E)AS2.

[0238] Step 5.21: The downlink data packet replied by (E)AS2 (source address IPas2, destination address IPue, source port number PORTas2, destination port number PORTue, transport layer protocol (such as UDP / TCP)) arrives at UPF / PSA2.

[0239] Step 5.22: UPF / PSA2 sends the downlink data packet to UPF / UL CL.

[0240] Step 5.23: According to the data packet processing rules sent by SMF in Step 5.11, if UPF / UL CL detects that the source address of the downlink IP packet is IPas2, the destination address is IPue, the source port number is PORTas2, and the transport layer protocol is such as UDP / TCP, it replaces the destination address of the downlink data packet that matches the data packet processing rules from IPas2 with IPas1, and replaces the source port number PORTas2 with PORTas1 (if PORT conversion is required in the data packet processing rules), and then sends the converted downlink data packet to the target UE.

[0241] Figure 10 In the embodiment, UPF / UL CL needs to perform matching, NAT conversion, and steering operations on the uplink and downlink data packets.

[0242] It should be noted that if the uplink data packet subsequently received by UPF / UL CL still matches the above data packet processing rules, it continues to be processed according to Steps 5.18 and 5.19 above. If the downlink data packet subsequently received by UPF / UL CL still matches the above data packet processing rules, it continues to be processed according to Steps 5.22 and 5.23 above. If the data packet processing rules contain a PORT item, PORT conversion is required.

[0243] Figure 11 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. Figure 11 The embodiment is similar to Figure 10 the embodiment, and the difference is that in Step 6.3, the migration from (E)AS1 to (E)AS2 is completed. Therefore, Figure 10 Step 5.16 in the embodiment is no longer executed.

[0244] Figure 11 Steps 6.1 - 4.2 in the embodiment are similar to Figure 10 Steps 5.1 - 5.2 in the embodiment, Figure 11 Steps 6.4 - 6.15 in the embodiment are similar to Figure 10 Steps 5.4 - 5.16 in the embodiment, Figure 11Steps 6.16 - 6.23 in the embodiment are the same as Figure 10 steps 5.17 - 5.24 in the embodiment.

[0245] In the method for implementing service continuity provided by the present disclosure, the AF can initiate the address change of the (E)AS in the cases of DNAI change and no change, so as to maintain service continuity. It can be applied to EC, which has great application value and can be widely applied to services such as game acceleration, video acceleration, and V2X (vehicle to everything). The NAT technical solution provided by the embodiment of the present disclosure is simple and feasible and easy to deploy. It only adds a new solution on the basis of the technical solutions of relevant standards. Therefore, the modification to the system is small and it is easy to be standardized and deployed on a large scale.

[0246] Figure 12 The flowchart schematically shows a method for implementing service continuity according to an embodiment of the present disclosure. Figure 12 The embodiment uses Early Notification to perform (E)AS Relocation in the case of DNAI change and determines that the UPF / PSA2 performs NAT conversion.

[0247] Steps 7.1 - 7.2 are the same as Figure 6 steps 1.1 - 1.2 in the embodiment, and Figure 12 in the embodiment, the AF subscribes to some events from the SMF. The event subscribed by the AF from the SMF is "UP_PATH_CH". The AF can directly subscribe to the SMF, or first subscribe to the target NEF, and then the target NEF subscribes to the SMF. The subscribed event "UP_PATH_CH" can be "EARLY", "LATE", or "EARLY_LATE". If the "UP_PATH_CH" subscribed by the AF from the SMF is "EARLY" or "EARLY_LATE", it is called that the AF sends an early event subscription message to the SMF.

[0248] Step 7.3. Due to the mobility of the target UE, the SMF can determine that the distance between the target UE and the UPF / PSA1 is relatively far according to the location of the target UE. The UPF / PSA1 is no longer suitable as the IP Anchor of the target UE to communicate with the external (E)AS1, and it is necessary to modify the protocol data unit session anchor user plane function network element and the user data routing. At this time, the Notification event subscribed by the AF on the SMF is triggered.

[0249] Step 7.4. When the SMF decides to modify the protocol data unit session anchor user plane function network element (add a UPF / PSA2 and a UPF / UL CL, and the DNAI is changed accordingly), and if the Notification event subscribed by the AF on the SMF is "EARLY" or "EARLY_LATE", the SMF initiates the Notification process. The SMF can directly send the Nsmf_EventExposure_Notify (Early Notification) message (Nsmf_EventExposure_Notify (Early Notification) message, that is, the early event notification message) to the AF or send it to the AF through the target NEF to report the Notification event. In this parameter of EventNotification, the SMF includes the target DNAI corresponding to the UPF / PSA2 and the source DNAI corresponding to the UPF / PSA1, the DnaiChangeType is EARLY, and the event type is "UP_PATH_CH".

[0250] Step 7.5. The AF triggers the (E)AS1 to migrate to the target DNAI to become (E)AS2.

[0251] Step 7.6. The AF replies to the SMF with the Nsmf_EventExposure_AppRelocationInfo message (Nsmf_EventExposure_AppRelocationInfo message, that is, the event exposure application relocation information message) indicating the successful migration of the (E)AS1. This message includes the target N6Traffic Routing Information, and this target N6 Traffic Routing Information includes the same parameters as the target N6 Traffic Routing Information in the above embodiments.

[0252] Figure 12 In the embodiment, when the SMF determines the operation of the UPF / PSA2 for NAT conversion, Steps 7.7 - 7.21 can be referred to Figure 9 Steps 4.7 - 4.24 in the embodiment.

[0253] Figure 13 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. Figure 13 The embodiment uses Early Notification to perform (E)ASRelocation in the case of DNAI change and determines that the UPF / ULCL performs NAT conversion.

[0254] Steps 8.1 - 8.6 are the same asFigure 12 Steps 7.1 - 7.6 of the embodiment.

[0255] Figure 13 In the embodiment, for the operation where the SMF determines the UPF / ULCL for NAT conversion, steps 8.7 - 8.20 can be referred to Figure 11 Steps 6.7 - 6.23 in the embodiment.

[0256] Figure 14 The flowchart schematically shows a method for implementing service continuity according to an embodiment of the present disclosure. Figure 14 The embodiment uses Late Notification, performs (E)AS Relocation in the case of DNAI change, and determines that the UPF / PSA2 performs NAT conversion.

[0257] Steps 9.1 - 9.2 are similar to steps 7.1 - 7.2 in Embodiment 12, the difference is that Figure 14 In the embodiment, if the event "UP_PATH_CH" subscribed by the AF to the SMF is "LATE (late)" or "EARLY_LATE" (early_late), it is called that the AF sends a late event subscription message to the SMF.

[0258] Step 9.3 is the same as step 7.3 in Embodiment 12.

[0259] Steps 9.4 - 9.7 are the same as steps 7.7 - 7.10 in Embodiment 12.

[0260] Step 9.8, the SMF configures the UPF / UL CL to still route all uplink data packets of the target UE to the UPF / PSA1, because at this time, the migration of (E)AS1 to (E)AS2 has not been completed, and at this time, any uplink data packets cannot be routed to the UPF / PSA2.

[0261] Step 9.9 is the same as step 7.13 in Embodiment 12.

[0262] Step 9.10, the SMF initiates the Notification process. The SMF can directly send an Nsmf_EventExposure_Notify (Late Notification) message (Nsmf_EventOpen_Notify (late notification) message, that is, a late event notification message) to the AF or through the target NEF to the AF to report the Notification event. Then the SMF includes the target DNAI corresponding to the UPF / PSA2 and the source DNAI corresponding to the UPF / PSA1 in this parameter of the EventNotification, the DnaiChangeType is LATE, and the event type is "UP_PATH_CH".

[0263] Step 9.11: AF triggers the migration of (E)AS1 to the target DNAI to become (E)AS2.

[0264] Step 9.12: AF replies to the SMF with the Nsmf_EventExposure_AppRelocationInfo message indicating the successful migration of (E)AS1 (Nsmf_EventExposure_Application Relocation Information message, i.e., the event exposure application relocation information message). This message contains the target N6Traffic Routing Information, and this target N6 Traffic Routing Information contains the same parameters as the target N6 Traffic Routing Information in the above embodiments.

[0265] Figure 14 In the embodiment, the SMF determines the operation of the UPF / PSA2 for NAT conversion. Steps 9.13 - 9.22 can refer to Figure 12 Steps 7.11 - 7.12 and steps 7.14 - 7.21 in the embodiment.

[0266] Figure 15 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. Figure 14 The embodiment uses Late Notification to perform (E)AS Relocation in the case of DNAI change and determines that the UPF / UL CL performs NAT conversion.

[0267] Steps 10.1 - 12 are the same as Figure 14 Steps 9.1 - 9.10 in the embodiment.

[0268] Step 10.13 is the same as Figure 13 Step 8.11 in the embodiment.

[0269] Steps 10.14 - 10.21 are the same as Figure 13 Steps 8.13 - 8.20 in the embodiment.

[0270] The method for implementing service continuity provided by the embodiments of the present disclosure can trigger the Early and Late Notification processes by the SMF when the routing between the current UPF / PSA1 of the UE and the (E)AS 1 becomes inappropriate due to the change of the UE's location, notify the (E)AS to migrate between different DNAIs, and at the same time, maintain the service continuity when the address of the (E)AS changes. It can be applied to EC, which has great application value and can be widely applied to services such as game acceleration, video acceleration, and V2X (vehicle-to-everything). The NAT technical solution provided by the embodiments of the present disclosure is simple and feasible and easy to deploy. It only adds a new solution on top of the technical solutions of relevant standards. Therefore, the modification to the system is small, and it is easy to standardize and deploy on a large scale.

[0271] Figure 16 Schematically shows a flowchart of a method for implementing service continuity according to an embodiment of the present disclosure. As Figure 16 shown, the method provided by the embodiments of the present disclosure may include the following steps.

[0272] In step S1610, a target N4 session request message sent by a session management function network element is received through a target user plane function network element, where the target N4 session request message includes a packet processing rule, and the packet processing rule includes a network address translation rule.

[0273] In step S1620, an uplink packet is received through the target user plane function network element.

[0274] In step S1630, if the target user plane function network element detects that the source address of the uplink packet is the target user equipment network address and the destination address is the first application server network address according to the packet processing rule, the destination address of the uplink packet is converted to the second application server network address according to the network address translation rule.

[0275] In an exemplary embodiment, if the target user plane function network element detects, according to the data packet processing rule, that the source address of the uplink data packet is the network address of the target user equipment and the destination address is the network address of the first application server, then according to the network address translation rule, converting the destination address of the uplink data packet into the network address of the second application server may include: if the target user plane function network element detects, according to the data packet processing rule, that the source address of the uplink data packet is the network address of the target user equipment, the destination address is the network address of the first application server, and the destination port number is the first port number of the first application server corresponding to the network address of the first application server, then according to the network address translation rule, converting the destination address of the uplink data packet into the network address of the second application server and converting the destination port number into the second port number of the second application server.

[0276] In step S1640, forward the uplink data packet whose destination address is converted into the network address of the second application server by the target user plane function network element to the second application server corresponding to the network address of the second application server.

[0277] In an exemplary embodiment, the method may further include: receiving a downlink data packet by the target user plane function network element; if the target user plane function network element detects, according to the data packet processing rule, that the source address of the downlink data packet is the network address of the second application server and the target address is the network address of the target user equipment, then according to the network address translation rule, converting the source address of the downlink data packet into the network address of the first application server; forwarding the downlink data packet whose source address is converted into the network address of the first application server by the target user plane function network element to the target user equipment corresponding to the network address of the target user equipment.

[0278] In an exemplary embodiment, if the target user plane function network element detects, according to the data packet processing rule, that the source address of the downlink data packet is the network address of the second application server and the target address is the network address of the target user equipment, then according to the network address translation rule, converting the source address of the downlink data packet into the network address of the first application server may include: if the target user plane function network element detects, according to the data packet processing rule, that the source address of the downlink data packet is the network address of the second application server, the target address is the network address of the target user equipment, and the source port number is the second port number of the second application server, then according to the network address translation rule, converting the source address of the downlink data packet into the network address of the first application server and converting the source port number into the first port number of the first application server corresponding to the network address of the first application server.

[0279] In an exemplary embodiment, the target user plane function network element may include a first protocol data unit session anchor user plane function network element.

[0280] In an exemplary embodiment, the target user plane function network element may include an uplink classifier user plane function network element and a second protocol data unit session anchor user plane function network element. The packet processing rule further includes a packet forwarding rule. The target N4 session request message includes a first N4 session request message and a second N4 session request message. Among them, receiving the target N4 session request message sent by the session management function network element through the target user plane function network element may include: receiving the first N4 session request message through the uplink classifier user plane function network element, and the first N4 session request message includes the packet forwarding rule; receiving the second N4 session request message through the second protocol data unit session anchor user plane function network element, and the second N4 session request message includes the network address translation rule.

[0281] In an exemplary embodiment, receiving an uplink packet through the target user plane function network element may include: receiving the uplink packet through the uplink classifier user plane function network element. Among them, if the target user plane function network element detects that the source address of the uplink packet is the target user equipment network address and the destination address is the first application server network address according to the packet processing rule, then converting the destination address of the uplink packet to the second application server network address according to the network address translation rule may include: the uplink classifier user plane function network element forwarding the uplink packet that matches the packet forwarding rule to the second protocol data unit session anchor user plane function network element; the second protocol data unit session anchor user plane function network element converting the destination address of the uplink packet detected and received from the uplink classifier user plane function network element from the first application server network address to the second application server address according to the network address translation rule. Among them, forwarding the uplink packet with the destination address converted to the second application server network address to the second application server corresponding to the second application server network address through the target user plane function network element may include: forwarding the uplink packet with the destination address converted to the second application server address to the second application server through the second protocol data unit session anchor user plane function network element.

[0282] In an exemplary embodiment, the second protocol data unit session anchor user plane function network element may convert the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address according to the network address conversion rule, which may include: the second protocol data unit session anchor user plane function network element converts the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address, and converts the destination port number from the first port number of the first application server corresponding to the first application server network address to the second port number of the second application server according to the network address conversion rule.

[0283] In an exemplary embodiment, the method may further include: receiving a downlink data packet through the second protocol data unit session anchor user plane function network element; if the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address and the destination address is the target user equipment network address, converting the source address of the downlink data packet to the first application server network address according to the network address conversion rule; the second protocol data unit session anchor user plane function network element forwards the downlink data packet with the source address converted to the first application server network address to the uplink classifier user plane function network element; the uplink classifier user plane function network element forwards the downlink data packet with the source address converted to the first application server network address to the target user equipment.

[0284] In an exemplary embodiment, if the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address, the destination address is the target user equipment network address, it may convert the source address of the downlink data packet to the first application server network address according to the network address conversion rule, which may include: if the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address, the destination address is the target user equipment network address, and the source port number is the second port number of the second application server, converting the source address of the downlink data packet to the first application server network address and converting the source port number to the first port number of the first application server corresponding to the first application server network address according to the network address conversion rule.

[0285] In an exemplary embodiment, the target user plane function network element may include an uplink classifier user plane function network element.

[0286] In an exemplary embodiment, before receiving the target N4 session request message, the method may further include: establishing a target protocol data unit session between the target user equipment corresponding to the network address of the target user equipment, so that the target user equipment communicates with the first application server corresponding to the first application server network address.

[0287] The specific implementation of the method for implementing service continuity provided by the embodiments of the present disclosure may refer to the content in the method for implementing service continuity in the above-mentioned other embodiments, and will not be repeated here.

[0288] Figure 17 Schematically shows a block diagram of an apparatus for implementing service continuity according to an embodiment of the present disclosure. As Figure 17 shown, the apparatus 1700 for implementing service continuity provided by the embodiment of the present disclosure may include: a relocation message receiving unit 1710, a processing rule generating unit 1720, and a processing rule sending unit 1730.

[0289] Among them, the relocation message receiving unit 1710 may be configured to receive a target relocation message, the target relocation message carries target data routing information, the target data routing information includes a target data network access identifier and network address conversion information, the network address conversion information includes a target user equipment network address, a first application server network address, and a second application server network address, wherein the target user equipment corresponding to the target user equipment network address has established a target protocol data unit session to the target protocol data unit session anchor user plane function network element and communicates with the first application server corresponding to the first application server network address. The processing rule generating unit 1720 may be configured to generate a data packet processing rule according to the target data routing information, the data packet processing rule includes a network address conversion rule, the network address conversion rule includes converting the destination address of the uplink data packet sent by the target user equipment from the first application server network address to the second application server network address, and converting the source address of the downlink data packet received with the destination address being the target user equipment network address from the second application server network address to the first application server network address. The processing rule sending unit 1730 may be configured to send the data packet processing rule to a target network device, so that the target network device forwards the uplink data packet sent by the target user equipment to the second application server corresponding to the second application server network address according to the data packet processing rule, and forwards the downlink data packet received with the destination address being the target user equipment network address and the source address being the second application server network address to the target user equipment.

[0290] In an exemplary embodiment, the target relocation message may include a session management policy control update notification message. Among them, the relocation message receiving unit 1710 may include: a session management policy control update notification message receiving unit, which may be used to receive the session management policy control update notification message from the target policy control function network element. The session management policy control update notification message may include a source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element, the target data network access identifier, and the target data routing information.

[0291] In an exemplary embodiment, the session management policy control update notification message may be generated by the target policy control function network element according to a policy authorization request message received from the target network exposure function network element. The policy authorization request message may include the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information. Among them, the policy authorization request message may be generated by the target network exposure function network element according to an impact data routing request message received from the application function network element. The impact data routing request message may include the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

[0292] In an exemplary embodiment, the session management policy control update notification message may be generated by the target policy control function network element according to an impact data routing request message received from the application function network element. The impact data routing request message may include the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

[0293] In an exemplary embodiment, if the target data network access identifier matches the source data network access identifier, the target network device may include the first protocol data unit session anchor user plane function network element. Among them, the processing rule distribution unit 1730 may include: an N4 session modification request message sending unit, which may be used to send an N4 session modification request message to the first protocol data unit session anchor user plane function network element. The N4 session modification request message includes the packet processing rule.

[0294] In an exemplary embodiment, the apparatus 1700 for implementing business continuity may further include: an N4 session modification response message receiving unit, configured to receive an N4 session modification response message replied by the N4 session anchor user plane function network element of the first protocol data unit; a session management policy control update notification response message returning unit, configured to return a session management policy control update notification response message to the target policy control function network element, so that the target policy control function network element returns an impact data routing response message to the application function network element, and after receiving the impact data routing response message, the application function network element triggers to complete migrating the first application server to the second application server.

[0295] In an exemplary embodiment, before receiving the target relocation message, the first application server has been migrated to the second application server through the application function network element.

[0296] In an exemplary embodiment, if the target data routing information may further include a first port number of the first application server and a second port number of the second application server, the network address translation rule may further include converting the destination port number of the uplink data packet from the first port number to the second port number, and converting the source port number of the downlink data packet from the second port number to the first port number.

[0297] In an exemplary embodiment, if the target data network access identifier does not match the source data network access identifier supported by the N4 session anchor user plane function network element of the first protocol data unit, the target network device may include a second N4 session anchor user plane function network element and an uplink classifier user plane function network element, and the data packet processing rule may further include a data packet forwarding rule, and the data packet forwarding rule may include forwarding an uplink data packet with a source address of the target user device network address and a destination address of the first application server network address to the second N4 session anchor user plane function network element. Among them, the processing rule issuing unit 1730 may include: a data packet forwarding rule issuing unit, configured to issue the data packet forwarding rule to the uplink classifier user plane function network element; a network address translation rule issuing unit, configured to issue the network address translation rule to the second N4 session anchor user plane function network element.

[0298] In an exemplary embodiment, the apparatus 1700 for implementing business continuity may further include: a user plane path change unit, which may be configured to determine the second protocol data unit session anchor user plane function element before sending the data packet processing rule to the target network device; determine the uplink classifier user plane function element; update the downlink user plane of the first protocol data unit session anchor user plane function element; and update the downlink user plane of the second protocol data unit session anchor user plane function element.

[0299] In an exemplary embodiment, if the target data network access identifier does not match the source data network access identifier supported by the first protocol data unit session anchor user plane function element, the target network device may include an uplink classifier user plane function element. Among them, the processing rule sending unit 1730 may include: an uplink classifier receiving packet processing rule unit, which may be configured to send the data packet processing rule to the uplink classifier user plane function element.

[0300] In an exemplary embodiment, the target relocation message may include an event open application relocation information message. Among them, the relocation message receiving unit 1710 may include: an event open application relocation information message receiving unit, which may be configured to receive the event open application relocation information message from the application function element, and the event open application relocation information message includes the target data routing information.

[0301] In an exemplary embodiment, the apparatus 1700 for implementing business continuity may further include: an early event notification unit, which may be configured to receive an early event subscription message of the application function element before receiving the target relocation message; decide to modify the protocol data unit session anchor user plane function element; and according to the decision to modify the protocol data unit session anchor user plane function element, transmit an early event notification message to the application function element, and the early event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function element.

[0302] In an exemplary embodiment, the apparatus 1700 for implementing business continuity may further include: a first application server migration unit, which may be configured to trigger the migration of the first application server from the source data network access identifier to the target data network access identifier by the application function element according to the early event notification message, and become the second application server.

[0303] In an exemplary embodiment, the data packet processing rule may further include a data packet forwarding rule. Among them, the apparatus 1700 for implementing service continuity may further include: a second uplink user plane function network element determination unit, which may be used to determine the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element after receiving the target relocation message; a first target network device determination unit, which may be used to use the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network device. Among them, the processing rule distribution unit 1730 may include: a data packet forwarding rule sending unit, which may be used to distribute the data packet forwarding rule to the uplink classifier user plane function network element; a network address conversion rule sending unit, which may be used to distribute the network address conversion rule to the second protocol data unit session anchor user plane function network element.

[0304] In an exemplary embodiment, the apparatus 1700 for implementing service continuity may further include: a user plane function network element addition unit, which may be used to determine the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element after receiving the target relocation message; a second target network device determination unit, which may be used to use the uplink classifier user plane function network element as the target network device. Among them, the processing rule distribution unit 1730 may include: a data packet processing rule sending unit, which may be used to distribute the data packet processing rule to the uplink classifier user plane function network element.

[0305] In an exemplary embodiment, the apparatus 1700 for implementing service continuity may further include: a late event notification unit, which may be used to receive a late event subscription message from the application function network element before receiving the target relocation message; decide to modify the protocol data unit session anchor user plane function network element; determine the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element according to the decision to modify the protocol data unit session anchor user plane function network element; configure the uplink classifier user plane function network element to forward the received uplink data packet to the first protocol data unit session anchor user plane function network element; transmit a late event notification message to the application function network element, where the late event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function network element.

[0306] In an exemplary embodiment, the apparatus 1700 for implementing service continuity may further include: a second application server migration unit, configured to trigger, according to the late event notification message, the application function network element to migrate the first application server from the source data network access identifier to the target data network access identifier, and the first application server becomes the second application server.

[0307] In an exemplary embodiment, the packet processing rule may further include a packet forwarding rule. The apparatus 1700 for implementing service continuity may further include: a third target network device determination unit, configured to, after receiving the target relocation message, use the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network device. The processing rule distribution unit 1730 may include: a packet forwarding rule transmission unit, configured to distribute the packet forwarding rule to the uplink classifier user plane function network element; and a network address translation rule transmission unit, configured to distribute the network address translation rule to the second protocol data unit session anchor user plane function network element.

[0308] In an exemplary embodiment, the apparatus 1700 for implementing service continuity may further include: a fourth target network device determination unit, configured to, after receiving the target relocation message, use the uplink classifier user plane function network element as the target network device. The processing rule distribution unit 1730 may include: a packet detection rule distribution unit, configured to distribute the packet processing rule to the uplink classifier user plane function network element.

[0309] The specific implementation of each unit in the apparatus for implementing service continuity provided by the embodiments of the present disclosure may refer to the content in the above method for implementing service continuity, and will not be elaborated herein.

[0310] Figure 18 A block diagram of a user plane function network element according to an embodiment of the present disclosure is schematically shown. As Figure 18 shown, the user plane function network element 1800 provided by the embodiment of the present disclosure may include: a session request message receiving unit 1810, an uplink packet receiving unit 1820, an uplink packet detection and conversion unit 1830, and an uplink packet forwarding unit 1840.

[0311] Among them, the session request message receiving unit 1810 can be used to receive a target N4 session request message sent by a session management function network element. The target N4 session request message includes a packet processing rule, and the packet processing rule includes a network address translation rule. The uplink packet receiving unit 1820 can be used to receive uplink packets. The uplink packet detection and conversion unit 1830 can be used to, if it is detected according to the packet processing rule that the source address of the uplink packet is the network address of the target user equipment and the destination address is the network address of the first application server, convert the destination address of the uplink packet to the network address of the second application server according to the network address translation rule. The uplink packet forwarding unit 1840 can be used to forward the uplink packet whose destination address is converted to the network address of the second application server to the second application server corresponding to the network address of the second application server.

[0312] In an exemplary embodiment, the uplink packet detection and conversion unit 1830 may include: a first destination port number conversion unit, which can be used to, if it is detected according to the packet processing rule that the source address of the uplink packet is the network address of the target user equipment, the destination address is the network address of the first application server, and the destination port number is the first port number of the first application server corresponding to the network address of the first application server, convert the destination address of the uplink packet to the network address of the second application server and the destination port number to the second port number of the second application server according to the network address translation rule.

[0313] In an exemplary embodiment, the user plane function network element 1800 may further include: a first downlink packet receiving unit, which can be used to receive downlink packets; a first source address conversion unit, which can be used to, if it is detected according to the packet processing rule that the source address of the downlink packet is the network address of the second application server and the target address is the network address of the target user equipment, convert the source address of the downlink packet to the network address of the first application server according to the network address translation rule; a first downlink packet forwarding unit, which can be used to forward the downlink packet whose source address is converted to the network address of the first application server to the target user equipment corresponding to the network address of the target user equipment.

[0314] In an exemplary embodiment, the first source address conversion unit may include: a first source port number conversion unit, which may be configured to, if it is detected according to the data packet processing rule that the source address of the downlink data packet is the network address of the second application server, the destination address is the network address of the target user equipment, and the source port number is the second port number of the second application server, convert the source address of the downlink data packet to the network address of the first application server and the source port number to the first port number of the first application server corresponding to the network address of the first application server according to the network address conversion rule.

[0315] In an exemplary embodiment, the user plane function network element may include a first protocol data unit session anchor user plane function network element.

[0316] In an exemplary embodiment, the user plane function network element may include an uplink classifier user plane function network element and a second protocol data unit session anchor user plane function network element. The data packet processing rule may further include a data packet forwarding rule. The target N4 session request message may include a first N4 session request message and a second N4 session request message. Among them, the session request message receiving unit 1810 may include: a first N4 session request message receiving unit, which may be configured to receive the first N4 session request message through the uplink classifier user plane function network element, and the first N4 session request message includes the data packet forwarding rule; a second N4 session request message receiving unit, which may be configured to receive the second N4 session request message through the second protocol data unit session anchor user plane function network element, and the second N4 session request message includes the network address conversion rule.

[0317] In an exemplary embodiment, the uplink data packet receiving unit 1820 may include: an uplink data packet obtaining unit, which may be configured to receive the uplink data packet through the uplink classifier user plane function network element. Among them, the uplink data packet detection and conversion unit 1830 may include: an uplink data packet sending unit, which may be configured to forward the uplink data packet matching the data packet forwarding rule by the uplink classifier user plane function network element to the second protocol data unit session anchor user plane function network element; a destination address conversion unit, which may be configured to convert the destination address of the uplink data packet detected and received from the uplink classifier user plane function network element by the second protocol data unit session anchor user plane function network element from the network address of the first application server to the address of the second application server according to the network address conversion rule. Among them, the uplink data packet forwarding unit 1840 may include: an uplink data packet transmission unit, which may be configured to forward the uplink data packet with the destination address converted to the address of the second application server to the second application server through the second protocol data unit session anchor user plane function network element.

[0318] In an exemplary embodiment, the destination address conversion unit may include: a second destination port number conversion unit, which may be used by the second protocol data unit session anchor user plane function network element to convert the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address, and convert the destination port number from the first port number of the first application server corresponding to the first application server network address to the second port number of the second application server according to the network address conversion rule.

[0319] In an exemplary embodiment, the user plane function network element 1800 may further include: a second downlink data packet receiving unit, which may be used to receive downlink data packets through the second protocol data unit session anchor user plane function network element; a second source address conversion unit, which may be used to convert the source address of the downlink data packet to the first application server network address according to the network address conversion rule if the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address and the destination address is the target user equipment network address; a second downlink data packet forwarding unit, which may be used by the second protocol data unit session anchor user plane function network element to forward the downlink data packet with the source address converted to the first application server network address to the uplink classifier user plane function network element; a third downlink data packet forwarding unit, which may be used by the uplink classifier user plane function network element to forward the downlink data packet with the source address converted to the first application server network address to the target user equipment.

[0320] In an exemplary embodiment, the second source address conversion unit may include: a second source port number conversion unit, which may be used to convert the source address of the downlink data packet to the first application server network address and convert the source port number to the first port number of the first application server corresponding to the first application server network address according to the network address conversion rule if the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address, the destination address is the target user equipment network address, and the source port number is the second port number of the second application server.

[0321] In an exemplary embodiment, the user plane function network element may include an uplink classifier user plane function network element.

[0322] In an exemplary embodiment, the user plane function network element 1800 may further include: a session establishment unit, which may be configured to establish a target protocol data unit session with a target user equipment corresponding to the target user equipment network address before receiving the target N4 session request message, so that the target user equipment communicates with a first application server corresponding to the first application server network address.

[0323] The specific implementation of each unit in the user plane function network element provided by the embodiments of the present disclosure may refer to the content in the above method for implementing service continuity, and will not be elaborated here.

[0324] Figure 19 A block diagram of a user equipment according to an embodiment of the present disclosure is schematically shown. As Figure 19 shown, the user equipment 1900 provided by the embodiment of the present disclosure may include: a session establishment unit 1910, an application server communication unit 1920, and an uplink data packet sending unit 1930.

[0325] Among them, the session establishment unit 1910 may be configured to establish a target protocol data unit session to a first protocol data unit session anchor user plane function network element. The application server communication unit 1920 may be configured to communicate with a first application server corresponding to the first application server network address. The uplink data packet sending unit 1930 may be configured to send an uplink data packet to a target network device, where the source address of the uplink data packet is the target network device network address and the destination address is the first application server network address, so that the target network device processes the uplink data packet according to a data packet processing rule, converts the destination address of the uplink data packet into a second application server network address, and forwards the uplink data packet with the destination address converted to the second application server network address to a second application server corresponding to the second application server network address.

[0326] In an exemplary embodiment, the user equipment 1900 may further include: a downlink data packet transfer unit, which may be configured to receive a downlink data packet from the target network device, where the source address of the downlink data packet is converted by the target network device from the second application server network address to the first application server network address according to the data packet processing rule, and the destination address of the downlink data packet is the target user equipment network address.

[0327] The specific implementation of each unit in the user equipment provided by the embodiments of the present disclosure may refer to the content in the above method for implementing service continuity, and will not be elaborated here.

[0328] It should be noted that although several units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more of the above-described units can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0329] From the description of the above embodiments, those skilled in the art can easily understand that the example embodiments described herein can be implemented by software or by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (such as a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

[0330] After considering the specification and practicing the invention disclosed herein, those skilled in the art will readily conceive of other embodiments of the present disclosure. This application is intended to cover any variations, uses, or adaptations of the present disclosure, which follow the general principles of the present disclosure and include known common knowledge or conventional technical means in the technical field not disclosed herein. The specification and examples are only regarded as exemplary, and the true scope and spirit of the present disclosure are pointed out by the following claims.

[0331] It should be understood that the present disclosure is not limited to the exact structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A method for implementing business continuity, characterized in that The method is executed by the SMF, and the method includes: Receiving a target relocation message from a target policy control function network element, where the target relocation message carries target data routing information, and the target data routing information includes a target data network access identifier and network address translation information. The network address translation information includes a target user equipment network address, a first application server network address, a first port number of the first application server, a second application server network address, and a second port number of the second application server. The target user equipment corresponding to the target user equipment network address has established a target protocol data unit session to a first protocol data unit session anchor user plane function network element and communicates with the first application server corresponding to the first application server network address; Generating a packet processing rule according to the target data routing information, where the packet processing rule includes a network address translation rule. The network address translation rule includes converting the destination address of an uplink packet sent by the target user equipment from the first application server network address to the second application server network address, converting the destination port number of the uplink packet from the first port number to the second port number, and converting the source address of a received downlink packet with the destination address being the target user equipment network address from the second application server network address to the first application server network address, and converting the source port number of the downlink packet from the second port number to the first port number; Sending the packet processing rule to a target network device, so that when the target network device detects that the source address of a received uplink packet is the target user equipment network address, the destination address is the first application server network address, and the destination port is the first port number according to the packet processing rule, after replacing the destination address of the uplink packet with the second application server network address and the destination port with the second port number, forwarding the uplink packet sent by the target user equipment to the second application server corresponding to the second application server network address, and after replacing the source address of a received downlink packet with the destination address being the target user equipment network address, the source address being the second application server network address, and the source port number being the second port number with the first application server network address and the source port number with the first port number, forwarding it to the target user equipment.

2. The method for implementing business continuity according to claim 1, wherein The target relocation message includes a session management policy control update notification message; wherein, receiving the target relocation message includes: Receiving the session management policy control update notification message from the target policy control function network element, and the session management policy control update notification message includes a source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element, the target data network access identifier, and the target data routing information.

3. The method for implementing business continuity according to claim 2, wherein, The session management policy control update notification message is generated by the target policy control function network element according to the policy authorization request message received from the target network exposure function network element. The policy authorization request message includes the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information; Among them, the policy authorization request message is generated by the target network exposure function network element according to the impact data routing request message received from the application function network element. The impact data routing request message includes the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

4. The method for implementing business continuity according to claim 2, wherein The session management policy control update notification message is generated by the target policy control function network element according to the impact data routing request message received from the application function network element. The impact data routing request message includes the target user equipment network address, the source data network access identifier, the target data network access identifier, and the target data routing information.

5. The method for implementing business continuity according to claim 2, wherein If the target data network access identifier matches the source data network access identifier supported by the first protocol data unit session anchor user plane function network element, the target network device includes the first protocol data unit session anchor user plane function network element; wherein, sending the packet processing rule to the target network device includes: Sending an N4 session modification request message to the first protocol data unit session anchor user plane function network element. The N4 session modification request message includes the packet processing rule.

6. The method for implementing business continuity according to claim 5, wherein It further includes: Receiving an N4 session modification response message replied by the first protocol data unit session anchor user plane function network element; Returning a session management policy control update notification response message to the target policy control function network element, so that the target policy control function network element returns an impact data routing response message to the application function network element. After receiving the impact data routing response message, the application function network element triggers the completion of migrating the first application server to the second application server.

7. The method for implementing business continuity according to claim 1, wherein Before receiving the target relocation message, the first application server has been migrated to the second application server through the application function network element.

8. The method for implementing business continuity according to claim 1, wherein If the target data network access identifier does not match the source data network access identifier supported by the first protocol data unit session anchor user plane function network element, the target network device includes a second protocol data unit session anchor user plane function network element and an uplink classifier user plane function network element. The packet processing rule further includes a packet forwarding rule. The packet forwarding rule includes forwarding the uplink packet with the source address being the target user equipment network address and the destination address being the first application server network address to the second protocol data unit session anchor user plane function network element; wherein, sending the packet processing rule to the target network device includes: Sending the packet forwarding rule to the uplink classifier user plane function network element; Sending the network address translation rule to the second protocol data unit session anchor user plane function network element.

9. The method for implementing business continuity according to claim 8, wherein, Before the packet processing rule is sent to the target network device, the method further includes: Determine the second protocol data unit session anchor user plane function network element; Determine the uplink classifier user plane function network element; Update the downlink user plane of the first protocol data unit session anchor user plane function network element; Update the downlink user plane of the second protocol data unit session anchor user plane function network element.

10. The method for implementing business continuity according to claim 1, characterized in that, If the target data network access identifier does not match the source data network access identifier supported by the first protocol data unit session anchor user plane function network element, the target network device includes an uplink classifier user plane function network element; wherein, sending the packet processing rule to the target network device includes: Send the packet processing rule to the uplink classifier user plane function network element.

11. The method for implementing business continuity according to claim 1, characterized in that, The target relocation message includes an event open application relocation information message; wherein, receiving the target relocation message includes: Receive the event open application relocation information message from the application function network element, and the event open application relocation information message includes the target data routing information.

12. The method for implementing business continuity according to claim 11, wherein Before receiving the target relocation message, the method further includes: Receive the early event subscription message of the application function network element; Decide to modify the protocol data unit session anchor user plane function network element; According to the decision to modify the protocol data unit session anchor user plane function network element, transmit an early event notification message to the application function network element, and the early event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function network element.

13. The method for implementing business continuity according to claim 12, wherein Further includes: The application function network element triggers the migration of the first application server from the source data network access identifier to the target data network access identifier according to the early event notification message and becomes the second application server.

14. The method for implementing business continuity according to claim 12, wherein The packet processing rule further includes a packet forwarding rule; wherein, after receiving the target relocation message, the method further includes: Determine the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element; Use the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network device; Wherein, sending the packet processing rule to the target network device includes: Send the packet forwarding rule to the uplink classifier user plane function network element; Send the network address translation rule to the second protocol data unit session anchor user plane function network element.

15. The method for implementing business continuity according to claim 12, wherein, After receiving the target relocation message, the method further includes: Determine the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element; Use the uplink classifier user plane function network element as the target network device; Wherein, sending the packet processing rule to the target network device includes: Send the packet processing rule to the uplink classifier user plane function network element.

16. The method for implementing business continuity according to claim 11, wherein Before receiving the target relocation message, the method further includes: Receiving a late event subscription message from the application function network element; Deciding to modify the user plane function network element as the protocol data unit session anchor; Determining a second protocol data unit session anchor user plane function network element and an uplink classifier user plane function network element according to the decision to modify the user plane function network element as the protocol data unit session anchor; Configuring the uplink classifier user plane function network element to forward the received uplink data packet to the first protocol data unit session anchor user plane function network element; Transmitting a late event notification message to the application function network element, where the late event notification message includes event notification parameters, and the event notification parameters include the source data network access identifier corresponding to the first protocol data unit session anchor user plane function network element and the target data network access identifier corresponding to the second protocol data unit session anchor user plane function network element.

17. The method for implementing business continuity according to claim 16, wherein It further includes: The application function network element triggers, according to the late event notification message, migrating the first application server from the source data network access identifier to the target data network access identifier to become the second application server.

18. The method for implementing business continuity according to claim 16, wherein The data packet processing rule further includes a data packet forwarding rule; wherein, after receiving the target relocation message, the method further includes: Regarding the second protocol data unit session anchor user plane function network element and the uplink classifier user plane function network element as the target network devices; Wherein, distributing the data packet processing rule to the target network device includes: Distributing the data packet forwarding rule to the uplink classifier user plane function network element; Distributing the network address translation rule to the second protocol data unit session anchor user plane function network element.

19. The method for implementing business continuity according to claim 16, wherein After receiving the target relocation message, the method further includes: Regarding the uplink classifier user plane function network element as the target network device; Wherein, distributing the data packet processing rule to the target network device includes: Distributing the data packet processing rule to the uplink classifier user plane function network element.

20. A method for implementing business continuity, characterized in that, It includes: Receiving, by the target user plane function network element, a target N4 session request message sent by the session management function network element, where the target N4 session request message includes a data packet processing rule, the data packet processing rule includes a network address translation rule, and the network address translation rule includes converting the destination address of the uplink data packet sent by the target user equipment from the first application server network address to the second application server network address, converting the destination port number of the uplink data packet from the first port number of the first application server to the second port number of the first application server, and converting the source address of the received downlink data packet with the destination address being the target user equipment network address from the second application server network address to the first application server network address, and converting the source port number of the downlink data packet from the second port number to the first port number; Receiving an uplink data packet through the target user plane function network element; If the target user plane function network element detects, according to the data packet processing rule, that the source address of the uplink data packet is the network address of the target user equipment, the destination address is the network address of the first application server, and the destination port is the first port number, then it converts the destination address of the uplink data packet to the network address of the second application server and replaces the destination port with the second port number according to the network address conversion rule; Forward the uplink data packet whose destination address is converted to the network address of the second application server and the destination port is replaced with the second port number by the target user plane function network element to the second application server corresponding to the network address of the second application server; Receive the downlink data packet through the target user plane function network element; If the target user plane function network element detects, according to the data packet processing rule, that the source address of the downlink data packet is the network address of the second application server, the target address is the network address of the target user equipment, and the source port number is the second port number, then it converts the source address of the downlink data packet to the network address of the first application server and replaces the source port number with the first port number according to the network address conversion rule; Forward the downlink data packet whose source address is converted to the network address of the first application server and the source port number is replaced with the first port number by the target user plane function network element to the target user equipment corresponding to the network address of the target user equipment.

21. The method for implementing business continuity according to claim 20, wherein The target user plane function network element includes a first protocol data unit session anchor user plane function network element.

22. The method for implementing business continuity according to claim 20, wherein The target user plane function network element includes an uplink classifier user plane function network element and a second protocol data unit session anchor user plane function network element. The data packet processing rule further includes a data packet forwarding rule. The target N4 session request message includes a first N4 session request message and a second N4 session request message; wherein, receiving the target N4 session request message sent by the session management function network element through the target user plane function network element includes: Receive the first N4 session request message through the uplink classifier user plane function network element, and the first N4 session request message includes the data packet forwarding rule; Receive the second N4 session request message through the second protocol data unit session anchor user plane function network element, and the second N4 session request message includes the network address conversion rule.

23. The method for implementing business continuity according to claim 22, wherein Receiving the uplink data packet through the target user plane function network element includes: Receive the uplink data packet through the uplink classifier user plane function network element; Wherein, if the target user plane function network element detects, according to the data packet processing rule, that the source address of the uplink data packet is the network address of the target user equipment and the destination address is the network address of the first application server, then converting the destination address of the uplink data packet to the network address of the second application server according to the network address conversion rule includes: The uplink classifier user plane function network element forwards the uplink data packet that matches the data packet forwarding rule to the second protocol data unit session anchor user plane function network element; The second protocol data unit session anchor user plane function network element converts the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address according to the network address conversion rule; Among them, forwarding the uplink data packet whose destination address is converted to the second application server network address to the second application server corresponding to the second application server network address through the target user plane function network element includes: Forwarding the uplink data packet whose destination address is converted to the second application server address to the second application server through the second protocol data unit session anchor user plane function network element.

24. The method for implementing business continuity according to claim 23, wherein The second protocol data unit session anchor user plane function network element converts the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address according to the network address conversion rule, including: The second protocol data unit session anchor user plane function network element converts the destination address of the detected uplink data packet received from the uplink classifier user plane function network element from the first application server network address to the second application server address, and converts the destination port number from the first port number of the first application server corresponding to the first application server network address to the second port number of the second application server according to the network address conversion rule.

25. The method for implementing business continuity according to claim 22, wherein It further includes: Receiving a downlink data packet through the second protocol data unit session anchor user plane function network element; If the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address and the destination address is the target user equipment network address, it converts the source address of the downlink data packet to the first application server network address according to the network address conversion rule; The second protocol data unit session anchor user plane function network element forwards the downlink data packet whose source address is converted to the first application server network address to the uplink classifier user plane function network element; The uplink classifier user plane function network element forwards the downlink data packet whose source address is converted to the first application server network address to the target user equipment.

26. The method for implementing business continuity according to claim 25, wherein If the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the second application server network address and the destination address is the target user equipment network address, converting the source address of the downlink data packet to the first application server network address according to the network address conversion rule includes: If the second protocol data unit session anchor user plane function network element detects that the source address of the downlink data packet is the network address of the second application server, the destination address is the network address of the target user equipment, and the source port number is the second port number of the second application server, it shall convert the source address of the downlink data packet to the network address of the first application server and the source port number to the first port number of the first application server corresponding to the network address of the first application server according to the network address translation rule.

27. The method for implementing business continuity according to claim 20, wherein The target user plane function network element includes an uplink classifier user plane function network element.

28. The method for implementing business continuity according to claim 20, wherein Before receiving the target N4 session request message, the method further includes: Establishing a target protocol data unit session with the target user equipment corresponding to the network address of the target user equipment, so that the target user equipment communicates with the first application server corresponding to the network address of the first application server.

29. A device for implementing business continuity, characterized in that, The device is disposed in the SMF, and the device includes: A relocation message receiving unit, configured to receive a target relocation message from a target policy control function network element, where the target relocation message carries target data routing information, the target data routing information includes a target data network access identifier and network address translation information, the network address translation information includes the network address of the target user equipment, the network address of the first application server, the first port number of the first application server, the network address of the second application server, and the second port number of the second application server, and a target protocol data unit session has been established between the target user equipment corresponding to the network address of the target user equipment and the first protocol data unit session anchor user plane function network element and communicates with the first application server corresponding to the network address of the first application server; A processing rule generating unit, configured to generate a data packet processing rule according to the target data routing information, where the data packet processing rule includes a network address translation rule, and the network address translation rule includes converting the destination address of the uplink data packet sent by the target user equipment from the network address of the first application server to the network address of the second application server, converting the destination port number of the uplink data packet from the first port number to the second port number, and converting the source address of the downlink data packet with the destination address being the network address of the target user equipment from the network address of the second application server to the network address of the first application server, and converting the source port number of the downlink data packet from the second port number to the first port number; A processing rule distribution unit, configured to distribute the data packet processing rule to a target network device, so that the target network device, according to the data packet processing rule, when detecting that the source address of an uplink data packet received is the target user equipment network address, the destination address is the first application server network address, and the destination port is the first port number, replaces the destination address of the uplink data packet with the second application server network address and the destination port with the second port number, and then forwards the uplink data packet sent by the target user equipment to the second application server corresponding to the second application server network address, and replaces the source address of a downlink data packet received with the destination address being the target user equipment network address, the source address being the second application server network address, and the source port number being the second port number with the first application server network address and the source port number with the first port number, and then forwards it to the target user equipment.

30. A user plane function network element, characterized in that, It includes: A session request message receiving unit, configured to receive a target N4 session request message sent by a session management function network element, where the target N4 session request message includes a data packet processing rule, the data packet processing rule includes a network address translation rule, and the network address translation rule includes converting the destination address of an uplink data packet sent by a target user equipment from a first application server network address to a second application server network address, converting the destination port number of the uplink data packet from a first port number of the first application server to a second port number of the first application server, and converting the source address of a downlink data packet received with the destination address being the target user equipment network address from the second application server network address to the first application server network address, and converting the source port number of the downlink data packet from the second port number to the first port number; An uplink data packet receiving unit, configured to receive an uplink data packet; An uplink data packet detection and conversion unit, configured to, if it is detected according to the data packet processing rule that the source address of the uplink data packet is the target user equipment network address, the destination address is the first application server network address, and the destination port is the first port number, convert the destination address of the uplink data packet to the second application server network address and replace the destination port with the second port number according to the network address translation rule; An uplink data packet forwarding unit, configured to forward the uplink data packet with the destination address converted to the second application server network address and the destination port replaced with the second port number to the second application server corresponding to the second application server network address; A first downlink data packet receiving unit, configured to receive a downlink data packet through a target user plane function network element; The first source address conversion unit is configured to, if the target user plane function network element detects that the source address of the downlink data packet is the second application server network address, the target address is the target user equipment network address, and the source port number is the second port number according to the data packet processing rule, convert the source address of the downlink data packet to the first application server network address and replace the source port number with the first port number according to the network address conversion rule; The first downlink data packet forwarding unit is configured to forward the downlink data packet with the source address converted to the first application server network address and the source port number replaced with the first port number to the target user equipment corresponding to the target user equipment network address through the target user plane function network element.

31. A user equipment, characterized in that, Comprising: The unit session establishment unit is configured to establish a target protocol data unit session to the user plane function network element of the first protocol data unit session anchor point; The application server communication unit is configured to communicate with the first application server corresponding to the first application server network address; The uplink data packet sending unit is configured to send an uplink data packet to the target network device, where the source address of the uplink data packet is the target network device network address, the destination address is the first application server network address, and the destination port is the first port number of the first application server, so that the target network device processes the uplink data packet according to the data packet processing rule, converts the destination address of the uplink data packet to the second application server network address and replaces the destination port with the second port number of the second application server, and forwards the uplink data packet with the destination address converted to the second application server network address and the destination port replaced with the second port number to the second application server corresponding to the second application server network address; wherein the data packet processing rule includes a network address conversion rule, and the network address conversion rule includes converting the destination address of the uplink data packet sent by the target user equipment from the first application server network address to the second application server network address, converting the destination port number of the uplink data packet from the first port number to the second port number, and converting the source address of the downlink data packet with the destination address being the target user equipment network address received from the second application server network address to the first application server network address, and converting the source port number of the downlink data packet from the second port number to the first port number; The downlink data packet transfer unit is configured to receive a downlink data packet from the target network device, where the source address of the downlink data packet is converted from the second application server network address to the first application server network address by the target network device according to the data packet processing rule, the source port number of the downlink data packet is converted from the second port number to the first port number by the target network device according to the data packet processing rule, and the destination address of the downlink data packet is the target user equipment network address.

32. An electronic device, characterized in that, Comprising: One or more processors; A storage device configured to store one or more programs which, when executed by one or more processors, cause the one or more processors to implement the method according to any one of claims 1 to 19 or the method according to any one of claims 20 to 28.

33. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1 to 19 or the method according to any one of claims 20 to 28.

34. A computer program product, comprising a computer program, characterized in that, When the computer program is executed, it implements the method according to any one of claims 1 to 19 or the method according to any one of claims 20 to 28.

Images