Method and related equipment for achieving communication continuity

Abstract

The disclosed embodiments provide a method and related equipment for achieving communication continuity. The method is applied to the AF corresponding to the UE, and the UE has established a connection with the source AS using the allocated UE source network address information. The method includes: determining to migrate the source AS to the target AS; transmitting a first NAT parameter to the SMF so that the SMF determines the target UPF / PSA, the target UPF / PSA is used to reallocate the UE target network address information for the UE, and generating and returning a second NAT parameter to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, performing NAT conversion on the received data packet based on the second NAT parameter; obtaining the second NAT parameter from the SMF; configuring a third NAT parameter for the target AS based on the second NAT parameter, and migrating the source AS to the target AS so that the target AS performs NAT conversion on the data packet based on the third NAT parameter.

Description

Technical Field

[0001] The present disclosure relates to the field of communication technology, and in particular to a method for implementing communication continuity, an application function, a target application server, a session management function, a user equipment, and a computer-readable storage medium. Background Art

[0002] When an AS (Application Server) is migrated, the network address of the AS will change, and the communication between the UE (User Equipment) and the AS will be interrupted, causing the ongoing service communication to be interrupted. Therefore, a technical problem that needs to be solved is: when the UE moves, how to migrate the AS to maintain service continuity (such as little communication delay); or when the AS migrates but the UE does not move, how to maintain service continuity (such as little communication delay).

[0003] In the related art, after the AS migrates to the target AS network address of the target AS, the context of the target AS is changed, and all the contexts related to the IP (Internet Protocol) protocol stack of the source AS are seamlessly modified to the target AS network address information, so that after the AS migrates to the target AS network address information, the continuity of IP communication with the UE is maintained.

[0004] However, this approach is based on the premise that the AS has the ability to modify the kernel's IP protocol stack context after migration. Therefore, this approach is not a standardized and widely used technology, that is, this capability is not available. Summary of the invention

[0005] The embodiments of the present disclosure provide a method for achieving communication continuity, an application function, a target application server, a session management function, a user device, and a computer-readable storage medium, which can maintain communication continuity when the application server of the user device is migrated.

[0006] The embodiment of the present disclosure provides a method for achieving communication continuity, which is applied to an AF (Application Function) corresponding to a UE, and the UE has established a connection with a source AS using the allocated UE source network address information; wherein the method includes: determining to migrate the source AS to a target AS; transmitting a first NAT (Network Address Translation) parameter to an SMF (Session Management Function) so that the SMF determines a target UPF (User Plane Function) / PSA (PDU (Protocol Data Unit) Session Anchor), the target UPF / PSA is used to reallocate UE target network address information for the UE, and generate and return a second NAT parameter to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, and perform NAT conversion on a received data packet based on the second NAT parameter; obtaining the second NAT parameter from the SMF; configuring a third NAT parameter for the target AS based on the second NAT parameter, and migrating the source AS to the target AS, so that the target AS performs NAT conversion on the data packet based on the third NAT parameter.

[0007] An embodiment of the present disclosure provides a method for achieving communication continuity, which is applied to a target AS; wherein the method includes: configuring a third NAT parameter using AF, wherein the third NAT parameter is generated according to the second NAT parameter of the target UPF / PSA; obtaining a data packet, wherein the data packet is a data packet generated by the target UPF / PSA after NAT conversion according to the second NAT parameter or a data packet generated by the target AS; performing NAT conversion on the data packet according to the third NAT parameter; if the data packet is a data packet generated by the target AS, sending the data packet after NAT conversion according to the third NAT parameter to the target UPF / PSA, so that the target UPF / PSA performs NAT conversion again according to the second NAT parameter.

[0008] An embodiment of the present disclosure provides a method for achieving communication continuity, which is applied to the SMF corresponding to the UE, and the UE has established a connection with the source AS using the allocated UE source network address information; wherein the method includes: obtaining a first NAT parameter from the AF; determining a target UPF / PSA so that the target UPF / PSA reallocates the UE target network address information for the UE and enables the UE to continue to use the UE source network address information; sending the first NAT parameter to the target UPF / PSA so that the target UPF / PSA generates a second NAT parameter based on the first NAT parameter, the UE target network address information and the UE source network address information; receiving the second NAT parameter from the target UPF / PSA, and the target UPF / PSA is used to perform NAT conversion on the received data packet according to the second NAT parameter; passing the second NAT parameter to the AF, so that the AF configures a third NAT parameter for the target AS according to the second NAT parameter, and migrates the source AS to the target AS, and the target AS is used to perform NAT conversion on the data packet according to the third NAT parameter.

[0009] An embodiment of the present disclosure provides a method for achieving communication continuity, which is applied to a UE, and the UE has established a connection with a source AS using the allocated UE source network address information; wherein the method includes: transmitting an uplink data packet to a target UPF / PSA, so that the target UPF / PSA performs a first NAT conversion on the uplink data packet according to a second uplink NAT parameter, generating and sending an uplink data packet after the first NAT conversion to a target AS, and the target AS is used to perform a second NAT conversion on the uplink data packet after the first NAT conversion according to a third uplink NAT parameter; receiving a downlink data packet through the target UPF / PSA, wherein the target AS is used to perform a third NAT conversion on the downlink data packet according to a third downlink NAT parameter, and the target UPF / PSA is used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter.

[0010] An embodiment of the present disclosure provides an application function, including: one or more processors; a memory 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 implement the method described in any of the above embodiments.

[0011] An embodiment of the present disclosure provides a target application server, including: one or more processors; a memory 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 implement the method described in any of the above embodiments.

[0012] An embodiment of the present disclosure provides a session management function, including: one or more processors; a memory 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 implement the method described in any of the above embodiments.

[0013] An embodiment of the present disclosure provides a user device, including: one or more processors; and a memory configured to store one or more programs, so that when the one or more programs are executed by the one or more processors, the one or more processors implement the method described in any of the above embodiments.

[0014] An embodiment of the present disclosure provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for achieving communication continuity as described in the above embodiment is implemented.

[0015] An embodiment of the present disclosure provides an electronic device, comprising: one or more processors; and a memory configured to store one or more programs, so that when the one or more programs are executed by the one or more processors, the one or more processors implement the method for achieving communication continuity as described in the above embodiments.

[0016] According to one aspect of the present application, a computer program product or a computer program is provided, the computer program product or the computer program comprising computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the methods provided in the above-mentioned various optional implementations.

[0017] In the technical solutions provided by some embodiments of the present disclosure, after the UE has established a connection with the source application server AS using the allocated UE source network address information and communicated, if the AF determines to migrate the source AS to the target AS, the AF can transmit the first NAT parameter to the SMF. In this way, the SMF can reselect the target UPF / PSA after receiving the first NAT parameter, and the target UPF / PSA can re-allocate new UE target network address information for the UE. The target UPF / PSA can generate a second NAT parameter based on the UE's original UE source network address information and the reallocated UE target network address information, as well as the first NAT parameter, so that when the target UPF / PSA receives a data packet, the target UPF / PSA can perform NAT conversion on the data packet based on the second NAT parameter. The target UPF / PSA can send the second NAT parameter to the SMF, and the SMF can pass the second NAT parameter to the AF. The AF can further configure the third NAT parameter for the target AS according to the received second NAT parameter. In this way, when the target AS obtains the data packet, it can perform NAT conversion on the obtained data packet according to the third NAT parameter, that is, the same data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the data packet finally obtained by the target AS remain unchanged with the source address and destination address initially sent by the UE, or the source address and destination address of the data packet finally obtained by the UE remain unchanged with the source address and destination address initially sent by the target AS. On the one hand, the use of network address translation technology can achieve service continuity when the AS migrates; on the other hand, the kernel does not need to be modified after the AS migrates, and it is easy to implement. It is an available and reliable technology to achieve communication continuity after the AS migrates, and it is easy to standardize and deploy on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of an EC architecture in the related art is shown.

[0019] Figure 2 A schematic diagram of another EC architecture in the related art is shown.

[0020] Figure 3 The flowchart of a method for achieving communication continuity according to an embodiment of the present disclosure is schematically shown.

[0021] Figure 4 The interactive diagram of a method for realizing communication continuity according to an embodiment of the present disclosure is schematically shown.

[0022] Figure 5 An interactive schematic diagram of a method for achieving communication continuity according to another embodiment of the present disclosure is schematically shown.

[0023] Figure 6 An interactive schematic diagram of a method for implementing communication continuity according to yet another embodiment of the present disclosure is schematically shown.

[0024] Figure 7 The schematic diagram shows the architecture of a target application server according to an embodiment of the present disclosure.

[0025] Figure 8 The schematic diagram shows the Figure 7 An interactive schematic diagram of a method for implementing communication continuity of a target application server is shown.

[0026] Fig. 9 The schematic diagram shows the architecture of a target application server according to another embodiment of the present disclosure.

[0027] Fig.10 The schematic diagram shows the Fig. 9 An interactive schematic diagram of a method for implementing communication continuity of a target application server is shown.

[0028] Fig.11 The flowchart schematically shows a method for achieving communication continuity according to another embodiment of the present disclosure.

[0029] Fig.12 A flowchart of a method for achieving communication continuity according to yet another embodiment of the present disclosure is schematically shown.

[0030] Fig.13 A flowchart of a method for achieving communication continuity according to yet another embodiment of the present disclosure is schematically shown.

[0031] Fig.14 The block diagram schematically shows an application function according to an embodiment of the present disclosure.

[0032] Fig.15 A block diagram of a target application server according to an embodiment of the present disclosure is schematically shown.

[0033] Fig.16 A block diagram schematically shows a session management function according to an embodiment of the present disclosure.

[0034] Fig.17 A block diagram of a user equipment according to an embodiment of the present disclosure is schematically shown. DETAILED DESCRIPTION

[0035] According to an embodiment of the present disclosure, the process described below with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a computer-readable storage medium, and the computer program includes a program code for executing the method shown in the flowchart.

[0036] 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 embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the following embodiment. For example, the electronic device may implement the following Figure 3 or Figure 4 or Figure 5 or Figure 6 or Figure 8 or Fig.10 or Fig.11 or Fig.12 or Fig.13 The steps shown.

[0037] EC (Edge Computing) minimizes the communication delay between UE and AS by deploying AS close to UE. EC includes two basic architectures: Figure 1 and Figure 2 shown.

[0038] Figure 1 In the present invention, UPF (User Plane Function) / PSA (PDU (Protocol Data Unit) Session Anchor) is deployed near the base station (AN (Access Network)), and EAS (Edge Application Server) is deployed in the DN (Data Network) connected to PSA.

[0039] Figure 2In the present invention, when UPF / PSA1 (hereinafter referred to as source protocol data unit session anchor user plane function, abbreviated as source UPF / PSA) is deployed in a central location, a UL CL (Uplink Classifier) / BP (Branching Point) is deployed near the base station AN, and then a UPF / PSA2 (also referred to as target protocol data unit session anchor user plane function, abbreviated as target UPF / PSA, sometimes also represented by PSA2) near the base station is separated, and EAS is deployed in the same DN of the local access (Local Access) connected to PSA2.

[0040] Right now Figure 1 No UL CL / BP access to EAS, Figure 2 Access EAS using UL CL / BP.

[0041] Above Figure 1 and Figure 2 In the specification, NEF stands for Network Exposure Function, and Nnef refers to the Nnef message for obtaining services provided by NEF. PCF stands for Policy Control Function, and Npcf refers to the Npcf message for obtaining services provided by PCF. AF stands for Application Function, and Naf refers to the Naf message for obtaining services provided by AF. AMF stands for Access and Mobility Management Function, and Namf refers to the Namf message for obtaining services provided by AMF. SMF stands for Session Management Function, and Nsmf refers to the Nsmf message for obtaining services provided by SMF. UE and AMF interact through the N1 interface, AMF and AN interact through the N2 interface, SMF and UPF interact through the N4 interface, AN and UPF interact through the N3 interface, UPF and DN interact through the N6 interface, and UPFs interact through the N9 interface.

[0042] Figure 3 The flowchart of a method for achieving communication continuity according to an embodiment of the present disclosure is schematically shown. Figure 3 The method provided in the embodiment may be applied to an application function AF corresponding to a UE, where the UE has established a connection with a source application server (denoted as a source AS) using the allocated UE source network address information, but the present disclosure is not limited thereto.

[0043] Among them, the UE source network address information, that is, the user equipment source network address information, may include the UE source IP address (user equipment source Internet Protocol address, expressed as IPue1) and the source UE port number (source user equipment port number, expressed as PORTue1).

[0044] like Figure 3 As shown, the method provided by the embodiment of the present disclosure may include the following steps.

[0045] In step S310, it is determined to migrate the source AS to a target AS (target application server).

[0046] The migration in the embodiments of the present disclosure refers to functionally moving the source AS to the target AS, which may include but is not limited to two forms:

[0047] 1) Application migration, which may include the following: Fig. 9 and Fig.10 Example.

[0048] Application migration is the process of moving software applications from one computing environment to another, including migrating applications from one data center to another, from a public cloud to a private cloud, or from a company's local deployment server to a cloud service provider's environment.

[0049] 2) Server migration can include the following: Figure 6 as well as Figure 7 and Figure 8 Example.

[0050] Server migration refers to the migration of IDC (Internet Data Center) servers, virtual machines, cloud hosts of other cloud platforms, or other types of servers from one place to another (such as migration between data centers, public clouds, private clouds, central clouds, and edge clouds).

[0051] Server migration can include but is not limited to physical server migration (similar to moving a computer after hibernation) and virtual machine migration, that is, migrating a VM (Virtual Machine) from one place to another. The migration of this VM is divided into hot migration and cold migration.

[0052] Migrating a physical server to the cloud is done by booting the Migrate for Compute Engine Connector ISO image from a virtual or physical DVD (Digital Video Disc), ROM (Read-Only Memory) / CD (Compact Disk) device into RAM (Random Access Memory). The Migrate for Compute Engine connector maps the local storage of the physical server and creates a stub VMware virtual machine as the management object for the Migrate for Compute Engine cloud migration operation.

[0053] The “determination” in the embodiment of the present disclosure refers to the AF making a decision to migrate the source AS to the target AS, that is, when the AF determines to migrate the source AS to the target AS, the migration has not been realized yet, but the migration will be realized in a subsequent step.

[0054] It should be noted that the technical solution proposed in the embodiment of the present disclosure can not only solve EC problems, but also solve non-EC problems. Therefore, no special explanation will be given below, and EC problems will no longer be specifically referred to, that is, the (E)AS mentioned below can be either EAS or AS. (E)AS1 is used below to represent the source application server or the source edge application server, and its corresponding source AS network address information may include the source AS IP address (expressed as IPas1) and the source AS port number (expressed as PORTas1); (E)AS2 represents the target application server or the target edge application server, and its corresponding target AS network address information may include the target AS IP address (expressed as IPas2) and the target AS port number (expressed as PORTas2).

[0055] In an exemplary embodiment, determining to migrate the source AS to the target AS may include: receiving an event open early notification message from an SMF; and determining to migrate the source AS to the target AS according to the event open early notification message.

[0056] In an exemplary embodiment, determining to migrate the source AS to the target AS may include: receiving a data impact early notification message from the NEF, wherein the NEF is used to receive an event open early notification message from the SMF, and sending the data impact early notification message to the AF according to the event open early notification message.

[0057] In step S320, a first NAT parameter is transmitted to the SMF so that the SMF determines a target UPF / PSA, the target UPF / PSA is used to reallocate UE target network address information for the UE, and a second NAT parameter is generated and returned to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, and NAT conversion is performed on the received data packet based on the second NAT parameter.

[0058] In the disclosed embodiment, AF transmits a first NAT parameter to SMF to instruct NAT conversion. After receiving the first NAT parameter, SMF reselects UPF / PSA2 which is different from UPF / PSA1 as the target UPF / PSA. The target UPF / PSA, i.e., the UE target network address information reallocated by UPF / PSA2 for the UE, i.e., the user equipment target network address information, may include the UE target IP address (expressed as IPue2) and the target UE port number (expressed as PORTue2). UPF / PSA2 may generate a second NAT parameter based on the first NAT parameter, the UE source network address information, and the UE target network address information, and return the second NAT parameter to SMF. UPF / PSA2 may also perform different NAT conversions on the received data packets (which may include uplink data packets sent by the UE, and downlink data packets sent by the target AS that have undergone one NAT conversion) based on the second NAT parameter.

[0059] In an exemplary embodiment, the first NAT parameter may include target AS network address information of the target AS, and the target AS network address information includes a target AS IP address and a target AS port number.

[0060] In an exemplary embodiment, transmitting the first NAT parameter to the SMF may include: sending an event open application relocation message to the SMF, wherein the event open application relocation message carries the target AS IP address and the target AS port number.

[0061] In an exemplary embodiment, transmitting the first NAT parameter to the SMF may include: sending a data impact application relocation information message to a network open function NEF, wherein the data impact application relocation information message carries the target AS IP address and the target AS port number, so that the NEF sends an event open application relocation message to the SMF, wherein the event open application relocation message carries the target AS IP address and the target AS port number.

[0062] In an exemplary embodiment, transmitting the first NAT parameter to the SMF may include: sending a policy authorization establishment / update request message to a policy control function PCF, wherein the policy authorization establishment / update request message carries the target AS IP address and the target AS port number, so that the PCF sends a session management policy control update notification message to the SMF, wherein the session management policy control update notification message carries the target AS IP address and the target AS port number.

[0063] In step S330, the second NAT parameters are obtained from the SMF.

[0064] In step S340, a third NAT parameter is configured for the target AS according to the second NAT parameter, and the source AS is migrated to the target AS, so that the target AS performs NAT conversion on the data packet according to the third NAT parameter.

[0065] In an exemplary embodiment, the data packet may include an uplink data packet sent by the UE, the second NAT parameter includes a second uplink NAT parameter, the target UPF / PSA may be used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter may include a third uplink NAT parameter, and the source AS network address information of the source AS may include a source AS IP address. Configuring the third NAT parameter for the target AS according to the second NAT parameter may include: generating the third uplink NAT parameter according to the second uplink NAT parameter.

[0066] In an exemplary embodiment, the target AS includes a middle-box and an internal target AS, the middle-box and the internal target AS are different network entities, communicate through a network connection, and the network address of the middle-box is the target AS IP address; wherein, configuring a third NAT parameter for the target AS according to the second NAT parameter, and migrating the source AS to the target AS may include: configuring the third uplink NAT parameter to the middle-box, so that the middle-box performs a second NAT conversion on an uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal target AS through a network connected to the internal target AS; using the source AS IP address of the source AS as the network address of the internal target AS, so that the internal target AS receives the uplink data packet from the middle-box through a network connected to the middle-box. Since the UL IP data packet obtained by the target AS at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the UL IP data packet obtained by (E)AS1, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0067] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, and the third NAT parameter may also include a third downlink NAT parameter. Wherein, configuring the third NAT parameter for the target AS according to the second NAT parameter and migrating the source AS to the target AS may also include: generating the third downlink NAT parameter according to the second downlink NAT parameter; configuring the third downlink NAT parameter to the middle box, so that the middle box performs a third NAT conversion on the downlink data packet sent by the internal target AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, and the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE. The downlink data packet received by the UE has the same source IP address, source Port Number, destination IP address, and destination Port Number as the downlink data packet received previously, so that the continuity of the downlink data packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0068] In an exemplary embodiment, the target AS may include a first NAT middleware and an internal source AS. Configuring a third NAT parameter for the target AS according to the second NAT parameter and migrating the source AS to the target AS may include: configuring the third uplink NAT parameter to the first NAT middleware, so that the first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal source AS; copying the entire image of the operating environment of the source AS (for example, through the virtual machine migration technology, after the source AS is migrated to the target AS, the source AS actually remains unchanged) to the internal source AS (so that the network address of the internal source AS is the source AS IP address), so that the internal source AS receives the uplink data packet through the first NAT middleware. Since the UL IP data packet obtained by the target AS at this time has the same source IP address, source port number, destination IP address, and destination port number as the UL IP data packet obtained by (E)AS1, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0069] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, and the third NAT parameter may also include a third downlink NAT parameter. Wherein, configuring the third NAT parameter for the target AS according to the second NAT parameter and migrating the source AS to the target AS may also include: generating the third downlink NAT parameter according to the second downlink NAT parameter; configuring the third downlink NAT parameter to the first NAT middleware, so that the first NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, and the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE. The downlink data packet received by the UE has the same source IP address, source Port Number, destination IP address, and destination Port Number as the downlink data packet received previously, so that the continuity of the downlink data packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0070] In an exemplary embodiment, the target AS may include a target IP protocol stack and an internal source AS running program, and the target IP protocol stack may include a second NAT middleware. Wherein, configuring a third NAT parameter for the target AS according to the second NAT parameter, and migrating the source AS to the target AS, may include: sending the third uplink NAT parameter to the target IP protocol stack so as to configure the third uplink NAT parameter to the second NAT middleware, the second NAT middleware performing a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, and obtaining the uplink data packet whose destination address is the source AS IP address; copying the running program of the source AS to the target AS to obtain the internal source AS running program, the internal source AS running program being the running program of the source AS (making the network address of the target IP protocol stack the target AS IP address), so that the internal source AS running program receives the uplink data packet whose destination address is the source AS IP address from the target IP protocol stack. Since the UL IP data packet obtained by the target AS at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the UL IP data packet obtained by (E)AS1, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0071] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, and the third NAT parameter may also include a third downlink NAT parameter. Wherein, configuring the third NAT parameter for the target AS according to the second NAT parameter and migrating the source AS to the target AS may also include: generating the third downlink NAT parameter according to the second downlink NAT parameter; sending the third downlink NAT parameter to the target IP protocol stack so as to configure the third downlink NAT parameter to the second NAT middleware, the second NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS running program according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE. The downlink data packet received by the UE has the same source IP address, source Port Number, destination IP address, and destination Port Number as the downlink data packet received previously, so that the continuity of the downlink data packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0072] In an exemplary embodiment, the UE source network address information may include a UE source IP address and a source UE port number, the UE target network address information may include a UE target IP address and a target UE port number, and the source AS network address information may further include a source AS port number.

[0073] Among them, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination address from the source AS IP address to the target AS IP address; the third uplink NAT parameter can be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination address from the target AS IP address to the source AS IP address; or, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter can be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination address from the target AS IP address to the source AS The target AS may convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, and the source port from the source UE port number to the target UE port number; the third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, and the source port from the target UE port number to the source UE port number; or the second uplink NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the target AS IP address to the source AS IP address, and the source port from the target UE port number to the source UE port number; The third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, the source port from the target UE port number to the source UE port number, and the destination port from the target AS port number to the source AS port number;Alternatively, the second uplink NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination port from the target AS port number to the source AS port number; or, the second uplink NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the source port from the source UE port number to the target UE port number, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the source port from the target UE port number to the source UE port number, and the destination port from the target AS port number to the source AS port number. ;

[0074] In an exemplary embodiment, the third downstream NAT parameter can be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, and the destination address from the UE source IP address to the UE target IP address; the second downstream NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination address from the UE target IP address to the UE source IP address; or, the third downstream NAT parameter can be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address. The third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE source IP address, and the source port from the source AS port number of the source AS to the target AS port number of the target AS; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, and the source port from the target AS port number to the source AS port number; or the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE target IP address to the UE source IP address, and the source port from the target AS port number to the source AS port number; The IP address is converted to the target ASIP address, the destination address is converted from the UE source IP address to the UE target IP address, the source port is converted from the source AS port number of the source AS to the target AS port number of the target AS, and the destination port is converted from the source UE port number to the target UE port number; the second downstream NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target ASIP address to the source AS IP address, the destination address is converted from the UE target IP address to the UE source IP address, the source port is converted from the target AS port number to the source AS port number, and the destination port is converted from the target UE port number to the source UE port number;Alternatively, the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination port from the target UE port number to the source UE port number; or the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the source port from the source AS port number of the source AS to the target AS port number of the target AS, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the source port from the target AS port number to the source AS port number, and the destination port from the target UE port number to the source UE port number. ;

[0075] Specifically, the NAT conversion in the embodiments of the present disclosure may include any one of the following six situations:

[0076] 1) Convert the source address and destination address of the uplink data packet or the downlink data packet.

[0077] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2 according to the second uplink NAT parameter, and converts the destination address from the IPas1 to IPas2, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1 according to the third uplink NAT parameter, and converts the destination address from IPas2 to IPas1, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0078] The target AS generates a downlink data packet to be sent to the UE. The source address of the downlink data packet is IPas1, and the destination address is IPue1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter, that is, converts the source address of the downlink data packet from IPas1 to IPas2, and converts the destination address from IPue1 to IPue2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and converts the source address of the downlink data packet after the third NAT conversion from IPas2 to IPas1, and converts the destination address from IPue2 to IPue1 according to the second downlink NAT parameter, obtains the downlink data packet after the fourth NAT conversion, and after two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0079] 2) Convert the source address, destination address and destination port of the uplink data packet or the downlink data packet.

[0080] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2 according to the second uplink NAT parameter, converts the destination address from the IPas1 to IPas2, and converts the destination port from PORTas1 to PORTas2, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1, converts the destination address from IPas2 to IPas1, and converts the destination port from PORTas2 to PORTas1 according to the third uplink NAT parameter, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0081] The target AS generates a downlink data packet to be sent to the UE, the source address of the downlink data packet is IPas1, the destination address is IPue1, and the destination port is PORTue1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter, that is, converts the source address of the downlink data packet from IPas1 to IPas2, the destination address from IPue1 to IPue2, and the destination port from PORTue1 to PORTue2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and converts the source address after the third NAT conversion from IPas2 to IPas1, the destination address from IPue2 to IPue1, and the destination port from PORTue2 to PORTue1 according to the second downlink NAT parameter, obtains the downlink data packet after the fourth NAT conversion, and after two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0082] 3) Convert the source address, source port and destination address of the uplink data packet or the downlink data packet.

[0083] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2 according to the second uplink NAT parameter, converts the destination address from the IPas1 to IPas2, and converts the source port from PORTue1 to PORTue2, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1, converts the destination address from IPas2 to IPas1, and converts the source port from PORTue2 to PORTue1 according to the third uplink NAT parameter, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0084] The target AS generates a downlink data packet to be sent to the UE, the source address of the downlink data packet is IPas1, the destination address is IPue1, and the source port is PORTas1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter, that is, converts the source address of the downlink data packet from IPas1 to IPas2, the destination address from IPue1 to IPue2, and the source port from PORTas1 to PORTas2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and converts the source address after the third NAT conversion from IPas2 to IPas1, the destination address from IPue2 to IPue1, and the source port from PORTas2 to PORTas1 according to the second downlink NAT parameter, to obtain the downlink data packet after the fourth NAT conversion. After two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0085] 4) Convert the source address, source port, destination address and destination port of the uplink data packet or the downlink data packet.

[0086] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2 according to the second uplink NAT parameter, converts the destination address from the IPas1 to IPas2, converts the source port from PORTue1 to PORTue2, and converts the destination port from PORTas1 to PORTas2, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1 according to the third uplink NAT parameter, converts the destination address from IPas2 to IPas1, converts the source port from PORTue2 to PORTue1, and converts the destination port from PORTas2 to PORTas1, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0087] The target AS generates a downlink data packet to be sent to the UE. The source address of the downlink data packet is IPas1, the destination address is IPue1, the source port is PORTas1, and the destination port is PORTue1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameters, that is, converts the source address of the downlink data packet from IPas1 to IPas2, the destination address from IPue1 to IPue2, the source port from PORTas1 to PORTas2, and the destination port from PORTue1 to PORTue2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and according to the second downlink NAT parameters, converts the source address after the third NAT conversion from IPas2 to IPas1, the destination address from IPue2 to IPue1, the source port from PORTas2 to PORTas1, and the destination port from PORTue2 to PORTue1, to obtain the downlink data packet after the fourth NAT conversion. After two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0088] 5) Convert the source address and destination port of the uplink data packet or the downlink data packet.

[0089] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2 according to the second uplink NAT parameter, and converts the destination port from PORTas1 to PORTas2, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1 according to the third uplink NAT parameter, and converts the destination port from PORTas2 to PORTas1, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination PortNumber.

[0090] The target AS generates a downlink data packet to be sent to the UE. The source address of the downlink data packet is IPas1, and the destination port is PORTue1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter, that is, converts the source address of the downlink data packet from IPas1 to IPas2, and the destination port from PORTue1 to PORTue2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and converts the source address after the third NAT conversion from IPas2 to IPas1, and the destination port from PORTue2 to PORTue1 according to the second downlink NAT parameter, to obtain the downlink data packet after the fourth NAT conversion. After two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0091] 6) Convert the source address, source port and destination port of the uplink data packet or the downlink data packet.

[0092] In this case, after the target UPF / PSA receives the uplink data packet sent by the UE, the target UPF / PSA converts the source address of the uplink data packet from IPue1 to IPue2, the source port from PORTue1 to PORTue2, and the destination port from PORTas1 to PORTas2 according to the second uplink NAT parameter, obtains the uplink data packet after the first NAT conversion, and sends it to the target AS; after the target AS receives the uplink data packet after the first NAT conversion from the target UPF / PSA, it converts the source address of the uplink data packet after the first NAT conversion from the IPue2 to IPue1, the source port from PORTue2 to PORTue1, and the destination port from PORTas2 to PORTas1 according to the third uplink NAT parameter, obtains the uplink data packet after the second NAT conversion, and after two NAT conversions, the uplink data packet after the second NAT conversion is the uplink data packet originally sent by the UE, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0093] The target AS generates a downlink data packet to be sent to the UE, the source address of the downlink data packet is IPas1, the source port is PORTas1, and the destination port is PORTue1. The target AS performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter, that is, converts the source address of the downlink data packet from IPas1 to IPas2, the source port from PORTas1 to PORTas2, and the destination port from PORTue1 to PORTue2, obtains the downlink data packet after the third NAT conversion, and sends it to the target UPF / PSA. The target UPF / PSA receives the downlink data packet after the third NAT conversion, and converts the source address after the third NAT conversion from IPas2 to IPas1, the source port from PORTas2 to PORTas1, and the destination port from PORTue2 to PORTue1 according to the second downlink NAT parameter, to obtain the downlink data packet after the fourth NAT conversion. After two NAT conversions, the downlink data packet after the fourth NAT conversion is the downlink data packet originally sent by the target AS, that is, it has the same source IP address, source Port Number, destination IP address, and destination Port Number.

[0094] Among them, in the above 5) and 6), for the uplink data packet, the destination address is not converted. At this time, it can be considered that the target AS and the source AS are in the same local area network, that is, IPas1 is equal to IPas2.

[0095] In the following examples, the above 4) is taken as an example, that is, the source address, source port, destination address and destination port of the uplink data packet or the downlink data packet are converted at the same time, but the present disclosure is not limited to this.

[0096] The method for achieving communication continuity provided by the embodiment of the present disclosure is that when the UE has established a connection with the source application server AS using the allocated UE source network address information to communicate, if the AF determines to migrate the source AS to the target AS, the AF can transmit a first NAT parameter to the SMF, so that the SMF can reselect the target UPF / PSA after receiving the first NAT parameter, and the target UPF / PSA can re-allocate new UE target network address information for the UE, and the target UPF / PSA can generate a second NAT parameter based on the original UE source network address information of the UE and the reallocated UE target network address information, as well as the first NAT parameter, so that when the target UPF / PSA receives a data packet, the target UPF / PSA can perform NAT conversion on the data packet based on the second NAT parameter. The target UPF / PSA can send the second NAT parameter to the SMF, and the SMF can pass the second NAT parameter to the AF. The AF can further configure the third NAT parameter for the target AS according to the received second NAT parameter. In this way, when the target AS obtains the data packet, it can perform NAT conversion on the obtained data packet according to the third NAT parameter, that is, the same data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the data packet finally obtained by the target AS remain unchanged with the source address and destination address initially sent by the UE, or the source address and destination address of the data packet finally obtained by the UE remain unchanged with the source address and destination address initially sent by the target AS. On the one hand, the use of network address translation technology can achieve service continuity when the AS migrates; on the other hand, the kernel does not need to be modified after the AS migrates, and it is easy to implement. It is an available and reliable technology to achieve communication continuity after the AS migrates, and it is easy to standardize and deploy on a large scale.

[0097] Combine the following Figure 4-10 right Figure 3 The methods provided in the examples are illustrative.

[0098] Figure 4 The interactive diagram of a method for realizing communication continuity according to an embodiment of the present disclosure is schematically shown.

[0099] exist Figure 4 In step 1 of the embodiment, the UE establishes a PDU session through SMF, UPF / PSA1.

[0100] exist Figure 4 In step 2 of the embodiment, the UE establishes an IP connection with (E)AS1 (the corresponding network address is represented as IPas1) to interact with services.

[0101] UPF / PSA1 allocates an IP address to the UE, denoted as IPue1. The UE establishes an IP connection with an (E)AS1 through the allocated IPue1 for IP communication. The information of UL (Uplink) data packets and DL (Downlink) data packets can be found in Figure 4 Step 16 and Step 21.

[0102] exist Figure 4 In step 3a of the embodiment, the SMF sends Nsmf_EventExposure_Notify (early notification) to the AF.

[0103] In the embodiment of the present disclosure, early notification is represented as Early Notification, and late notification is represented as Late Notification below.

[0104] If the SMF finds that the UE is far away from its original location, it determines to trigger the migration of (E)AS1 to a target application server (E)AS2 that is closer to the UE, and therefore sends Nsmf_EventExposure_Notify (Early Notification), i.e., an event exposure early notification message, to the AF.

[0105] exist Figure 4 In step 4 of the embodiment, after receiving Nsmf_EventExposure_Notify (EarlyNotification) from SMF, AF determines to migrate (E)AS1 to (E)AS2.

[0106] It should be noted that, in the embodiment of the present disclosure, the AF may determine to migrate (E)AS1 to (E)AS2 according to the Nsmf_EventExposure_Notify (Early Notification) sent by the SMF, but in other embodiments, the AF may also trigger the migration of (E)AS1 to another target application server (E)AS2 (for example, if (E)AS1 is about to be overloaded), so Figure 4 Step 3a in is optional, but the present disclosure does not limit this.

[0107] exist Figure 4 In step 5a of the embodiment, the AF sends Nsmf_EventExposure_AppRelocationInfo (IPas2 and PORTas2) to the SMF.

[0108] like Figure 4If step 3a in the above is executed, the AF sends Nsmf_EventExposure_AppRelocationInfo (IPas2 and PORTas2), i.e., an event exposure application relocation message, to the SMF, and the event exposure application relocation message includes IPas2 of (E)AS2. Optionally, it may also include the PortNumber (port number) of (E)AS2 that communicates with the UE, i.e., PORTas2. Figure 4 Step 5a in is also optional.

[0109] exist Figure 4 In step 6 of the embodiment, the AF sends a Npcf_PolicyAuthorization_Create / Update request (IPas2 and PORTas2) to the PCF.

[0110] like Figure 4 If steps 3a and 5a in the above are not executed, but the AF initiates a command to update the route, the AF sends Npcf_PolicyAuthorization_Create / Update Request (request), i.e., a policy authorization establishment / update request message, to the PCF, and the policy authorization establishment / update request message includes IPas2. Optionally, PORTas2 may also be included.

[0111] exist Figure 4 In step 7 of the embodiment, after receiving the Npcf_PolicyAuthorization_Create / Update request (IPas2 and PORTas2) from the AF, the PCF sends Npcf_SMPolicyControl_UpdateNotify (IPas2 and PORTas2) to the SMF.

[0112] The PCF sends Npcf_SMPolicyControl_UpdateNotify, i.e., a session management policy control update notification message, to the SMF, and the session management policy control update notification message includes IPas2. Optionally, PORTas2 may also be included at the same time. Figure 4 Steps 6 and 7 in are optional.

[0113] Figure 4 Step 8a of the embodiment is optional, and is an anchor relocation procedure of SSC mode 2 or SSC mode 3 of the PDU session (the allocated IPue2 is not delivered to the UE).

[0114] If the SMF determines to initiate the Anchor relocation of SSC (Session and Service Continuity) Mode 2 or SSC Mode 3 of the PDU Session, then for SSC Mode 2 and SSC Mode 3, the SMF selects a new PSA2, and PSA2 allocates a new IPue2 address for this UE, but may not pass this IPue2 address to the UE, that is, the UE still uses the previous IPue1 (the UE is required to use the previous IP address), but in the following step 17, PSA2 will convert the previous IPue1 into the new IPue2 through NAT. PSA2 allocates the corresponding CN Tunnel Information (core network tunnel information, where CN is Core Network) and transmits the core network tunnel information to the SMF. The SMF selects a new UL CL (Uplink Classifer) / BP (Branching Point) as the target UL CL / BP, and then sends a message to the UL CL / BP and RAN (Radio AN, radio access network, Figure 4 (not shown) configure the core network tunnel information.

[0115] The CN Tunnel Information may include GTP-U (General packet radio service Tunnel Protocol-User) tunnel IP address (GTP-U tunnel IP address) and TEID (Tunnel Endpoint Identifier) ​​information (TEID information).

[0116] exist Figure 4 In step 8b of the embodiment, SMF sends an N4 session establishment request message (N4 SessionEstablishment Request) to PSA2, and PSA2 returns an N4 session establishment response message (N4 SessionEstablishment Response) to SMF.

[0117] If step 8a is not performed, but SMF determines to add or modify PSA2 of UL CL / BP, SMF selects a new PSA2, PSA2 allocates a new IPue2 address for this UE, but does not pass this IPue2 address to the UE, that is, the UE still uses the previous IPue1, but in the following step 17, PSA2 converts the previous IPue1 to the new IPue2 through NAT. PSA2 allocates the corresponding CN Tunnel Information and transmits the CN Tunnel Information to SMF.

[0118] The manner in which AF transmits the first NAT parameter to SMF is not limited to the several manners listed above.

[0119] In the above steps 8a and 8b, the SMF also sends indication information to PSA2 to instruct PSA2 to buffer the UL data packets before receiving the data transmission notification.

[0120] exist Figure 4 In step 9 of the embodiment, the SMF sends an N4 session establishment request message (N4 SessionEstablishment Request) to the UL CL / BP, and the UL CL / BP returns an N4 session establishment response message (N4 SessionEstablishment Response) to the SMF.

[0121] SMF selects a new UL CL / BP and then configures the CN TunnelInformation allocated by PSA2 to the UL CL / BP and RAN.

[0122] exist Figure 4 In step 10 of the embodiment, if the UE sends a UL IP, i.e., an uplink data packet, to the UL CL / BP at this time, and the UL CL / BP then sends the received uplink data packet to PSA2, PSA2 will first cache the uplink data packet. PSA2 does not immediately send the uplink data packet to N6, but buffers it until after step 15.

[0123] exist Figure 4 In step 11 of the embodiment, SMF sends an N4 session command (N4Session Command) to PSA2, instructing PSA2 to perform NAT conversion and redirection.

[0124] SMF sends a NAT instruction to PSA2, instructing it to convert IPas1 and PORTas1 of (E)AS1 into IPas2 and PORTas2 of (E)AS2. It can also instruct it to convert IPue1 of UE into the new IPue2 of UE.

[0125] exist Figure 4 In step 12 of the embodiment, PSA2 returns an N4 Session Response (N4Session Response) to SMF, and the N4 Session Response carries the second NAT parameter, and the second NAT parameter includes IPas2. Optionally, it may also include PORTas2.

[0126] PSA2 replies to SMF and may indicate in the second NAT parameter that PORTue1 of UE is converted to PORTue2. The second NAT parameter may include a second uplink NAT parameter and a second downlink NAT parameter, wherein the second uplink NAT parameter refers to a parameter used by PSA2 to perform NAT conversion on uplink data packets sent by UE, and the second downlink NAT parameter refers to a parameter used by PSA2 to perform NAT conversion on downlink data packets received from the target AS (here, downlink data packets that have undergone the third NAT conversion).

[0127] exist Figure 4 In step 13 of the embodiment, the SMF sends Nsmf_EventExposure_Notify(LateNotification, NAT parameters (IPas2 and PORTas2)), that is, an event exposure late notification message, to the AF.

[0128] SMF notifies AF that the switch from (E)AS1 to (E)AS2 is available through Nsmf_EventExposure_Notify (Late Notification, NAT parameters (IPas2 and PORTas2)). The event exposure late notification message includes NAT parameters, for example, indicating that IPas1 and PORTas1 of (E)AS1 are converted to IPas2 and PORTas2 of (E)AS2, IPue1 of UE is converted to UE's new IPue2, and PORTue1 of UE is converted to PORTue2.

[0129] exist Figure 4 In step 14 of the embodiment, AF migrates (E)AS1 to (E)AS2.

[0130] After receiving Nsmf_EventExposure_Notify (Late Notification, NAT parameters (IPas2 and PORTas2)), AF migrates (E)AS1 to (E)AS2. The IP address of (E)AS2 has been changed to IPas2.

[0131] exist Figure 4In step 15 of the embodiment, SMF sends an N4 Session Command (ie, data transmission notification) to PSA2 to notify PSA2 that it can start sending uplink data packets and receiving downlink data packets through the N6 interface, and PSA2 also needs to perform NAT conversion.

[0132] exist Figure 4 In step 16 of the embodiment, the UE sends a UL IP data packet (ie, the above-mentioned UL data packet), ie, an uplink data packet, to the UL CL / BP, and the UL CL / BP then forwards the uplink data packet to PS A2.

[0133] For example, the UE continues to send a UL data packet, the source address of the UL data packet is IPue1, the destination address is IPas1, the source port is PORTue1, and the destination port is PORTas1. The UL data packet may also include a transport protocol, which is represented as a UL IP data packet (source IPue1, destination IPas1, source port PORTue1, destination port PORTas1, transport protocol).

[0134] exist Figure 4 In step 17 of the embodiment, PSA2 performs a first NAT conversion on the uplink data packet according to the second uplink NAT parameter to obtain the uplink data packet after the first NAT conversion.

[0135] For example, PSA2 performs the first NAT conversion of the UL IP data packet, converts IPas1 and PORTas1 into IPas2 and PORTas2, converts IPue1 into IPue2, and converts PORTue1 into PORTue2, and obtains the UL IP data packet after the first NAT conversion (source IPue2, destination IPas2, source port PORTue2, destination port PORTas2, transmission protocol).

[0136] exist Figure 4 In step 18 of the embodiment, PSA2 sends the uplink data packet after the first NAT conversion to (E)AS2.

[0137] For example, PSA2 sends the UL IP data packet (source IPue2, destination IPas2, source port PORTue2, destination port PORTas2, transport protocol) after the first NAT conversion to (E)AS2.

[0138] After receiving the UL IP data packet (source IPue2, destination IPas2, source port PORTue2, destination port PORTas2, transport protocol) after the first NAT conversion, (E)AS2 will also perform a second NAT conversion on it to obtain a UL IP data packet (source IPue1, destination IPas1, source port PORTue1, destination port PORTas1, transport protocol), see the following for details. Figure 6-Figure 10 Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source Port Number, destination IP address, and destination Port Number, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0139] exist Figure 4 In step 19 of the embodiment, (E)AS2 generates a DL IP data packet, ie, a downlink data packet, and sends the downlink data packet to PSA2.

[0140] (E) AS2 generates a downlink data packet, for example, it can be represented as a DL IP data packet (source IP as1, destination IP ue1, source port PORT as1, destination port PORT ue1, transport protocol); (E) AS2 performs a third NAT conversion on it, and then sends the downlink data packet after the third NAT conversion to PSA2. For example, the downlink data packet after the third NAT conversion can be represented as a DL IP data packet (source IP as2, destination IP ue2, source port PORT as2, destination port PORT ue2, transport protocol), see the following for details. Figure 6-Figure 10 .

[0141] exist Figure 4 In step 20 of the embodiment, after PSA2 receives the third NAT-converted downlink data packet sent by the target AS, it performs a fourth NAT conversion on the third NAT-converted downlink data packet received from the target AS according to the second downlink NAT parameter to obtain the fourth NAT-converted downlink data packet.

[0142] For example, the downlink data packet after the third NAT conversion can be represented as a DL IP data packet (source IPas2, destination IPue2, source port PORTas2, destination port PORTue2, transmission protocol), and PS A2 again performs a fourth NAT conversion on the received downlink data packet after the third NAT conversion to obtain a DL IP data packet (source IPas1, destination IPue1, source port PORTas1, destination port PORT Tue1, transmission protocol).

[0143] exist Figure 4In step 21 of the embodiment, PSA2 sends the downlink data packet after the fourth NAT conversion to the UL CL / BP, and the UL CL / BP forwards it to the UE.

[0144] For example, PSA2 sends a DL IP data packet (source IP as1, destination IP ue1, source port PORT as1, destination port PORT ue1, transport protocol) to UL CL / BP, and then reaches UE through RAN. Since the DL IP data packet received by the UE at this time has the same source IP address, source port number, destination IP address, and destination port number as the DL data packet sent by (E) AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0145] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0146] In the embodiment of the present disclosure, since the UL and DL data packets corresponding to the above steps 16 and 21 are consistent with the information of the UL and DL data packets in step 2, that is, the source address, destination address, source port and destination port are not changed, the IP connection is maintained, and thus the continuity of the service is guaranteed. Figure 6-Figure 10 The embodiment is used to illustrate how the IP connection can be maintained after the IP address of (E)AS2 is changed to IPas2.

[0147] Figure 5 An interactive schematic diagram of a method for achieving communication continuity according to another embodiment of the present disclosure is schematically shown.

[0148] Figure 5 Embodiment and above Figure 4 The difference of the embodiment is that steps 3b and 3c are used instead of Figure 4 and replace step 3a with steps 5b and 5c Figure 4 Replace step 5a with steps 13a and 13b Figure 4 Follow step 13 in the tutorial.

[0149] exist Figure 5 In step 3b of the embodiment, the SMF sends Nsmf_EventExposure_Notify (EarlyNotification), ie, an event exposure early notification message, to the NEF.

[0150] exist Figure 5In step 3c of the embodiment, after receiving Nsmf_EventExposure_Notify (EarlyNotification), NEF sends Nnef_TrafficInfluence_Notify (Early Notification), that is, a data impact early notification message, to AF.

[0151] exist Figure 5 In step 5b of the embodiment, the AF sends Nnef_TrafficInfluence_AppRelocationInfo (IPas2 and PORTas2), ie, a data impact application relocation information message, to the NEF.

[0152] exist Figure 5 In step 5c of the embodiment, after NEF receives Nnef_TrafficInfluence_AppRelocationInfo (IPas2 and PORTas2), NEF sends Nsmf_EventExposure_AppRelocationInfo (IPas2 and PORTas2), ie, an event exposure application relocation message, to SMF.

[0153] exist Figure 5 In step 13a of the embodiment, SMF sends Nsmf_EventExposure_Notify (late notification, NAT parameters (IPas2 and PORTas2)), that is, an event exposure late notification message, to NEF.

[0154] exist Figure 5 In step 13b of the embodiment, after receiving Nsmf_EventExposure_Notify (late notification, NAT parameters (IPas2 and PORTas2)), NEF sends Nnef_TrafficInfluen ce_Notify (late notification, NAT parameters (IPas2 and PORTas2)), that is, a data impact late notification message, to AF.

[0155] Figure 6 An interactive schematic diagram of a method for implementing communication continuity according to yet another embodiment of the present disclosure is schematically shown. Figure 6 The process of the embodiment is Figure 4 or Figure 5 Refinement on the AF and (E)AS2 sides based on .

[0156] like Figure 6As shown, (E)AS2 may include MB (Middle-Box) and I-(E)AS2 (internal target AS). That is, the user context data of the Application of (E)AS1 and the entire operating system it runs are all migrated to I-(E)AS2, that is, I-(E)AS2 maintains the same application and system context as the original (E)AS1, which is equivalent to moving (E)AS1 to I-(E)AS2. At the same time, a middle box is deployed in front of I-(E)AS2, so that the middle box and I-(E)AS2 form an (E)AS2. MB and I-(E)AS2 are different network entities and communicate through a network connection. I-(E)AS2 maintains the IPas1 address of (E)AS1 unchanged, and the context of the connection with the UE does not change.

[0157] Figure 6 Embodiment and above Figure 4 and Figure 5 The difference between the embodiments is that the above step 14 can be split into step 14-1 and step 14-2, step 18 can be further followed by step 18-1 and step 18-2, and step 19 can be further followed by step 19-1 and step 19-2.

[0158] exist Figure 6 In step 14-1 of the embodiment, the AF sets the third NAT parameter on the MB.

[0159] In the disclosed embodiment, the third NAT parameter may include a third uplink NAT parameter and a third downlink NAT parameter, wherein the third uplink NAT parameter refers to the parameter for the target AS to perform NAT conversion on the uplink data packet after the first NAT conversion received from the target UPF / PSA, and the third downlink NAT parameter refers to the parameter for the target AS to perform NAT conversion on the downlink data packet generated by itself.

[0160] Specifically, the AF can generate a third upstream NAT parameter according to the second upstream NAT parameter provided in step 13, generate a third downstream NAT parameter according to the second downstream NAT parameter, and then send the third upstream NAT parameter and the third downstream NAT parameter to the MB to instruct the MB to perform NAT conversion corresponding to PSA2.

[0161] However, the present disclosure is not limited to this. For example, the AF may also directly send the second uplink NAT parameter and the second downlink NAT parameter to the target AS, and the target AS generates the third uplink NAT parameter according to the second uplink NAT parameter and generates the third downlink NAT parameter according to the second downlink NAT parameter.

[0162] For example, for a UL data packet, the first NAT conversion of PSA2 is: converting the destination address IPas1 of the UL data packet to IPas2, converting the destination port PORTas1 to PORTas2, converting the source address IPue1 of the UL data packet to IPue2, and converting the source port PORTue1 to PORTue2 (see Figure 4 In step 17 of the above, AF requires MB to perform the second NAT conversion on the UL data packet after the first NAT conversion: convert IPas2 and PORTas2 into IPas1 and PORTas1, and convert IPue2 and PORTue2 into IPue1 and PORTue1 (see step 18-1 below). Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source Port Number, destination IP address, and destination Port Number, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0163] For example, for DL ​​data packets, the fourth NAT conversion of PSA2 is: converting the source address IPas2 of the DL data packet after the third NAT conversion into IPas1, converting the source port PORTas2 into PORTas1, converting the destination address IPue2 of the DL data packet after the third NAT conversion into IPue1, and converting the destination port IPORTue2 into PORTue1 (see step 20), then AF requires MB to perform the third NAT conversion of the DL data packet: converting IPue1 and PORTue1 into IPue2 and PORTue2, and converting IPas1 and PORTas1 into IPas2 and PORTas2. Since the DL IP data packet received by the UE and the DL data packet sent by (E)AS1 have the same source IP address, source PortNumber, destination IP address, and destination Port Number, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0164] There is no restriction on how AF selects MB for (E)AS2. In addition, before sending the MB message, AF already knows that the IP address corresponding to MB is IPas2, and has provided this IPas2 address to PSA2 in the previous step.

[0165] exist Figure 6 In step 14-2 of the embodiment, AF migrates (E)AS1 to I-(E)AS2, and I-(E)AS2 keeps all the original IP contexts of (E)AS1, that is, the address of IPas1 remains unchanged, and the context of the connection with the UE remains unchanged.

[0166] AF migrates all user contexts of (E)AS1 to I-(E)AS2. I-(E)AS2 keeps all the original IP contexts of (E)AS1, that is, the address of IPas1 remains unchanged, and the context of the connection with the UE remains unchanged, that is, the IP address of I-(E)AS2 is also IPas1. The external IP address of MB is IPas2, and MB and I-(E)AS2 are combined to form (E)AS2, so the external network address of (E)AS2 is IPas2.

[0167] exist Figure 6 In step 18-1 of the embodiment, after receiving the uplink data packet after the first NAT conversion from PSA2, MB performs a second NAT conversion on the uplink data packet after the first NAT conversion to obtain the uplink data packet.

[0168] For example, MB performs the corresponding second NAT conversion on the UL data packet after the first NAT conversion, converts IPas2 and PORTas2 into IPas1 and PORTas1, and converts IPue2 and PORTue2 into IPue1 and PORTue1, thereby obtaining a UL IP data packet (source IPue1, destination IPas1, source port PORTue1, destination port PORTas1, transmission protocol).

[0169] exist Figure 6 In step 18-2 of the embodiment, the MB sends the uplink data packet to I-(E)AS2.

[0170] MB forwards the UL data packet after the second NAT conversion (i.e., the UL data packet sent by the UE) to I-(E)AS2. Since the source address, destination address, source port, destination port and transmission protocol of the UL data packet are not changed, I-(E)AS2 can continue to communicate with the UE seamlessly.

[0171] exist Figure 6 In step 19-1 of the embodiment, I-(E)AS2 generates a downlink data packet and sends it to the MB.

[0172] I-EAS2 sends a DL data packet, for example, it is assumed to be a DL IP data packet (source IPas1, destination IPue1, source port PORTas1, destination port PORTue1, transport protocol).

[0173] exist Figure 6 In step 19-2 of the embodiment, after receiving the downlink data packet from I-(E)AS2, MB performs a third NAT conversion on the downlink data packet to generate a downlink data packet after the third NAT conversion, and sends the downlink data packet after the third NAT conversion to PSA2.

[0174] For example, MB performs the third NAT conversion on the DL data packet, converting IPue1 and PORTue1 into IPue2 and PORTue2, and converting IPas1 and PORTas1 into IPas2 and PORTas2, thereby generating a DL IP data packet after the third NAT conversion (source IPas2, destination IPue2, source port PORT as2, destination port PORTue2, transport protocol).

[0175] PSA2 performs a fourth NAT conversion on the received downlink data packet that has undergone the third NAT conversion, and then sends the downlink data packet to the UE. Since the DL IP data packet received by the UE at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the DL IP data packet sent by (E)AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0176] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0177] Figure 6 The other steps in the Figure 4 and Figure 5 Example.

[0178] Figure 7 The following schematically shows the architecture of a target application server according to an embodiment of the present disclosure. Figure 7 As shown, (E)AS2 may include NAT MW (NAT Middle Ware, i.e., the first NAT middleware, Figure 8 In the example, (E)AS1 is an internal source AS and (E)AS2 is an internal source AS. A VM (Virtual Machine) technology is used on the target application server where (E)AS2 is located. That is, (E)AS1 is migrated to (E)AS2 as a VM, which is represented by I-(E)AS1.

[0179] Same as above Figure 6In this embodiment, all the user contexts of the Application of (E)AS1 are migrated to I-(E)AS1, that is, I-(E)AS1 keeps all the original IP contexts of (E)AS1, that is, the address of IPas1 remains unchanged, and the context of the connection with the UE remains unchanged. A NAT MW is connected between the IP protocol stack 2 on the target application server of (E)AS2 and I-(E)AS1, wherein the functions performed by the NAT MW are the same as those of the UE. Figure 6 The functions performed by the MB in the embodiments are the same.

[0180] See also Figure 7 It can be seen that I-(E)AS1 has the IP protocol stack 1 of (E)AS1. NAT MW can modify the IP protocol stack 2 of (E)AS2 so that NAT MW obtains the uplink data packet after the first NAT conversion sent by PSA2, and performs the second NAT conversion on the uplink data packet after the first NAT conversion to obtain the uplink data packet. NAT MW transmits the uplink data packet to I-(E)AS1 through its API (Application Programming Interface).

[0181] Figure 8 The schematic diagram shows the Figure 7 An interactive schematic diagram of a method for implementing communication continuity of a target application server is shown.

[0182] Figure 8 Embodiment and above Figure 4 and Figure 5 The difference between the embodiments is that the above step 14 can be split into step 14-1 and step 14-2, step 18 can be further followed by step 18-1 and step 18-2, and step 19 can be further followed by step 19-1 and step 19-2.

[0183] exist Figure 8 In step 14-1 of the embodiment, the AF sets the third NAT parameter on the MW. In the embodiment of the present disclosure, the third NAT parameter may include a third uplink NAT parameter and a third downlink NAT parameter.

[0184] Specifically, the AF can generate a third upstream NAT parameter based on the second upstream NAT parameter provided in step 13, generate a third downstream NAT parameter based on the second downstream NAT parameter, and then send the third upstream NAT parameter and the third downstream NAT parameter to the MW to instruct the MW to perform NAT conversion corresponding to PSA2.

[0185] exist Figure 8In step 14-2 of the embodiment, AF migrates (E)AS1 to I-(E)AS1 (as VM), and I-(E)AS1 (as VM) retains all the original IP contexts of (E)AS1, that is, the address of IPas1 remains unchanged, and the context of the connection with the UE remains unchanged.

[0186] exist Figure 8 In step 18-1 of the embodiment, after receiving the uplink data packet after the first NAT conversion from PSA2, MW performs a second NAT conversion on the uplink data packet after the first NAT conversion to obtain the uplink data packet.

[0187] exist Figure 8 In step 18-2 of the embodiment, MW sends the uplink data packet to I-(E)AS1 (as VM). Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source PortNumber, destination IP address, and destination PortNumber, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0188] exist Figure 8 In step 19-1 of the embodiment, I-(E)AS1 (as VM) generates a downlink data packet and sends it to the MW.

[0189] exist Figure 8 In step 19-2 of the embodiment, after MW receives the downlink data packet from I-(E)AS1 (as VM), it performs a third NAT conversion on the downlink data packet, generates a downlink data packet after the third NAT conversion, and sends the downlink data packet after the third NAT conversion to PSA2, so that PSA2 performs a fourth NAT conversion on the downlink data packet after the third NAT conversion.

[0190] Figure 8 Similar embodiments Figure 6 The flowchart of the embodiment is only that the MB is replaced by the NAT MW, and the interaction between the MB and the I-(E)AS2 is an external interface, while the interaction between the NAT MW and the I-(E)AS1 is an internal interface.

[0191] PSA2 performs a fourth NAT conversion on the received downlink data packet that has undergone the third NAT conversion, and then sends the downlink data packet to the UE. Since the DL IP data packet received by the UE at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the DL IP data packet sent by (E)AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0192] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0193] Fig. 9 Schematically shows a schematic diagram of the architecture of a target application server according to another embodiment of the present disclosure. Fig. 9 As shown, (E)AS2 may include IP protocol stack 2 (target IP protocol stack) of (E)AS2 and I-(E)AS1 (internal source AS running application), and IP protocol stack 2 further includes NAT MW (second NAT middleware, Fig.10 The running program of (E)AS1 is migrated to (E)AS2. (E)AS2 has I-(E)AS1, and I-(E)AS1 is the running application of (E)AS1. It does not have IP protocol stack 1 of (E)AS1. IP protocol stack 2 obtains the uplink data packet after the first NAT conversion sent by PSA2, and uses NAT MW in IP protocol stack 2 to perform a second NAT conversion on the uplink data packet after the first NAT conversion to obtain an uplink data packet. IP protocol stack 2 transmits the uplink data packet to I-(E)AS1 (internal source AS running program) through its API.

[0194] Fig. 9 Example and Figure 7 The difference between the embodiments is that Fig. 9 The I-(E)AS1 in the embodiment is not a VM of (E)AS1 (the VM of (E)AS1 has a copy of the entire operating environment of (E)AS1 on this VM). Here, the user context of (E)AS1 is migrated to (E)AS2. However, since the IP address of (E)AS2 has changed, a NAT Middle Ware is installed on (E)AS2 (equivalent to installing a VPN (Virtual Private Network) software on the computer) to map IPas2 of (E)AS2 to IPas1. That is, from the perspective of I-(E)AS1, the IP address of the entire server is IPas1, but in fact, its external IP address is IPas2. Please note that there is no IP protocol stack 1 on I-(E)AS1 at this time. Figure 7 In the embodiment, I-(E)AS1 has its own virtual network card and IP protocol stack 1.

[0195] Fig.10 The schematic diagram shows the Fig. 9An interactive schematic diagram of a method for implementing communication continuity of a target application server is shown.

[0196] Fig.10 Embodiment and above Figure 4 and Figure 5 The difference between the embodiments is that the above step 14 can be split into step 14-1 and step 14-2, step 18 can be further followed by step 18-1 and step 18-2, and step 19 can be further followed by step 19-1 and step 19-2.

[0197] exist Fig.10 In step 14-1 of the embodiment, the AF sets the third NAT parameters (including the third uplink NAT parameters and the third downlink NAT parameters) on the IP protocol stack 2, and the IP protocol stack 2 further includes the MW.

[0198] Specifically, the AF may generate a third NAT parameter according to the second NAT parameter, and then send the third NAT parameter to the IP protocol stack 2, and the IP protocol stack 2 passes the third NAT parameter to the MW therein.

[0199] exist Fig.10 In step 14-2 of the embodiment, AF migrates (E)AS1 to I-(E)AS1 (internal source AS running program), and I-(E)AS1 (internal source AS running program) maintains all the original IP contexts of (E)AS1, that is, the address of IPas1 remains unchanged, and the context of the connection with the UE remains unchanged.

[0200] exist Fig.10 In step 18-1 of the embodiment, after receiving the uplink data packet after the first NAT conversion from PSA2, IP protocol stack 2 uses MW therein to perform a second NAT conversion on the uplink data packet after the first NAT conversion to obtain the uplink data packet.

[0201] exist Fig.10 In step 18-2 of the embodiment, IP protocol stack 2 sends the uplink data packet to I-(E)AS1 (internal source AS running program). Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source port number, destination IP address, and destination port number, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0202] exist Fig.10 In step 19 - 1 of the embodiment, I-(E)AS1 (internal source AS running program) generates a downlink data packet and sends it to IP protocol stack 2 .

[0203] exist Fig.10 In step 19-2 of the embodiment, after receiving the downlink data packet from I-(E)AS1 (internal source AS running program), IP protocol stack 2 uses the MW therein to perform a third NAT conversion on the downlink data packet to generate a downlink data packet after the third NAT conversion, and IP protocol stack 2 sends the downlink data packet after the third NAT conversion to PSA2.

[0204] PSA2 performs a fourth NAT conversion on the received downlink data packet that has undergone the third NAT conversion, and then sends the downlink data packet to the UE. Since the DL IP data packet received by the UE at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the DL IP data packet sent by (E)AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0205] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0206] Fig.10 Similar embodiments Figure 6 The flowchart of the embodiment is only that the MB is replaced by the NAT MW, and the interaction between the MB and the I-(E)AS2 is an external interface, while the interaction between the NAT MW and the I-(E)AS1 is an internal interface.

[0207] The method for achieving communication continuity provided by the embodiment of the present disclosure is that for uplink data packets, after the previous network (e.g., 5G network) migrates from (E)AS1 to (E)AS2, the new IPas2 of (E)AS2 is NAT-converted (the IP address of (E)AS is changed), and then the external IP address of (E)AS2 is NAT-converted again, and the new external IP address after NAT conversion is converted to the IPas1 of (E)AS1 before migration, so that only the external IP address corresponding to (E)AS2 is changed (i.e., from IPas1 to IPas2), but the IP address of the (E)AS inside (E)AS2 (the above-mentioned I-(E)AS2 or I-(E)AS1) itself remains unchanged, i.e., it still remains as IPas1, thereby achieving communication continuity of the IP address.

[0208] For uplink data packets, if the previous 5G network performs NAT conversion on the new IPas2 of (E)AS2 and also performs NAT conversion on the port parameters after (E)AS1 migrates to (E)AS2 (i.e., the IP address of (E)AS and the destination port of (E)AS and / or the source port of UE are changed), then the external IP address of (E)AS2 is NAT converted again, and the new external IP address after NAT conversion is converted to the IPas1 of (E)AS1 before migration, and the changed destination port and / or source port are NAT converted, so that only (E)AS1 The external IP address and destination port and / or source port corresponding to S2 have changed (i.e., changed from IPas1 to IPas2, changed from PORTas1 to PORTas2, and / or changed from PORTue1 to PORTue2), but the IP address of the (E)AS inside (E)AS2 (the above-mentioned I-(E)AS2 or I-(E)AS1) itself remains unchanged, i.e., it still remains IPas1, the destination port still remains PORTas1, and / or the source port still remains PORTue1, thereby achieving communication continuity of the IP address.

[0209] Due to the bidirectional nature of communication, the processing of UL and DL IP packets is symmetrical.

[0210] Fig.11 The flowchart schematically shows a method for achieving communication continuity according to another embodiment of the present disclosure. Fig.11 The method provided in the embodiment can be applied to the target application server, that is, the target AS. Fig.11 As shown, the method provided by the embodiment of the present disclosure may include the following steps.

[0211] In step S1110, the source AS is migrated to the target AS by configuring the third NAT parameter using the AF, where the third NAT parameter is generated according to the second NAT parameter of the target UPF / PSA.

[0212] In step S1120, a data packet is acquired, wherein the data packet is a data packet generated by the target UPF / PSA after performing NAT conversion according to the second NAT parameter or a data packet generated by the target AS.

[0213] In step S1130, NAT conversion is performed on the data packet according to the third NAT parameter.

[0214] In step S1140, if the data packet is a data packet generated by the target AS, the data packet after NAT conversion according to the third NAT parameter is sent to the target UPF / PSA, so that the target UPF / PSA performs NAT conversion again according to the second NAT parameter.

[0215] In an exemplary embodiment, the data packet may include an uplink data packet sent by the UE, the second NAT parameter may include a second uplink NAT parameter, the target UPF / PSA may be used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter may include a third uplink NAT parameter, the source AS network address information of the source AS may include a source AS IP address, and the AF may be used to generate the third uplink NAT parameter based on the second uplink NAT parameter.

[0216] In an exemplary embodiment, the target AS may include an intermediate box and an internal target AS, wherein the intermediate box and the internal target AS are different network entities and communicate through a network connection, and the network address of the intermediate box is the target AS IP address of the target AS. Wherein, using the AF to configure the third NAT parameter to migrate the source AS to the target AS may include: the intermediate box obtains the third uplink NAT parameter from the AF; and uses the source ASIP address of the source AS as the network address of the internal target AS through the AF. Wherein, performing NAT conversion on the data packet according to the third NAT parameter may include: the intermediate box receives an uplink data packet after a first NAT conversion from the target UPF / PSA; the intermediate box performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; and the intermediate box sends the uplink data packet to the internal target AS through a network connected to the internal target AS. Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source Port Number, destination IP address, and destination Port Number, the continuity of the ULIP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0217] In an exemplary embodiment, the data packet may further include a downlink data packet, the second NAT parameter may further include a second downlink NAT parameter, the third NAT parameter may further include a third downlink NAT parameter, and the AF may further be used to generate the third downlink NAT parameter according to the second downlink NAT parameter. Wherein, configuring the third NAT parameter using the AF may further include: the middle box body obtains the third downlink NAT parameter from the AF. Wherein, performing NAT conversion on the data packet according to the third NAT parameter may further include: the internal target AS sends the downlink data packet to the middle box body; the middle box body performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the middle box body sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE. Since the DL IP data packet received by the UE at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the DL data packet sent by (E)AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0218] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0219] In an exemplary embodiment, the target AS may include a first NAT middleware and an internal source AS. The use of AF to configure the third NAT parameter to migrate the source AS to the target AS may include: the first NAT middleware obtains the third uplink NAT parameter from the AF; the entire image of the operating environment of the source AS is copied to the internal source AS through the AF (so that the network address of the internal source AS is the source AS IP address). The NAT conversion of the data packet according to the third NAT parameter may include: the first NAT middleware receives the uplink data packet after the first NAT conversion from the target UPF / PSA; the first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; the first NAT middleware sends the uplink data packet to the internal source AS. Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source port number, destination IP address, and destination port number, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0220] In an exemplary embodiment, the data packet may further include a downlink data packet, the second NAT parameter may further include a second downlink NAT parameter, the third NAT parameter may further include a third downlink NAT parameter, and the AF is further used to generate the third downlink NAT parameter according to the second downlink NAT parameter. Wherein, configuring the third NAT parameter using the AF may further include: the first NAT middleware obtains the third downlink NAT parameter from the AF. Wherein, performing NAT conversion on the data packet according to the third NAT parameter may further include: the internal source AS sends the downlink data packet to the first NAT middleware; the first NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the first NAT middleware sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE. Since the DL IP data packet received by the UE at this time has the same source IP address, source Port Number, destination IP address, and destination Port Number as the DL data packet sent by (E)AS1, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0221] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0222] In an exemplary embodiment, the target AS may include a target IP protocol stack and an internal source AS running program, and the target IP protocol stack may include a second NAT middleware. Wherein, using AF to configure the third NAT parameter to migrate the source AS to the target AS may include: the target IP protocol stack obtains the third uplink NAT parameter from the AF; the target IP protocol stack configures the third uplink NAT parameter to the second NAT middleware; the running program of the source AS is copied to the target AS through the AF to obtain the internal source AS running program, and the internal source AS running program is used as the running program of the source AS (making the network address of the target IP protocol stack the target AS IP address). Wherein, performing NAT conversion on the data packet according to the third NAT parameter may include: the target IP protocol stack receives an uplink data packet after the first NAT conversion from the target UPF / PSA; the second NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet whose destination address is the source AS IP address; the target IP protocol stack sends the uplink data packet whose destination address is the source AS IP address to the internal source AS running program. Since the UL IP data packet obtained by (E)AS2 and the UL IP data packet obtained by (E)AS1 have the same source IP address, source Port Number, destination IP address, and destination Port Number, the continuity of the UL IP packet data connection can be achieved, thereby achieving the continuity of the UL IP service.

[0223] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, the third NAT parameter may also include a third downlink NAT parameter, and the AF may also be used to generate the third downlink NAT parameter according to the second downlink NAT parameter. Wherein, using the AF to configure the third downlink NAT parameter may also include: the target IP protocol stack obtains the third downlink NAT parameter from the AF; the target IP protocol stack configures the third downlink NAT parameter to the second NAT middleware. Wherein, performing NAT conversion on the data packet according to the third NAT parameter may also include: the internal source AS runs a program to send a downlink data packet to the target IP protocol stack; the second NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the target IP protocol stack sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE. Since the DL IP data packet received by the UE and the DL data packet sent by (E)AS1 have the same source IP address, source Port Number, destination IP address, and destination Port Number, the continuity of the DL IP packet data connection can be achieved, thereby achieving the continuity of the DL IP service.

[0224] At the same time, since both UL and DL IP data packets can achieve the continuity of IP packet data connection, the continuity of UL and DL IP services can be achieved, so the continuity of the entire IP service is guaranteed.

[0225] The specific implementation of the method for achieving communication continuity provided by the embodiment of the present disclosure can refer to the contents of the method for achieving communication continuity in other embodiments mentioned above, and will not be repeated here.

[0226] Fig.12 A flowchart of a method for achieving communication continuity according to yet another embodiment of the present disclosure is schematically shown. Fig.12 The method provided in the embodiment can be applied to a session management function SMF corresponding to a user equipment UE, where the UE has established a connection with a source application server AS using the allocated UE source network address information. Fig.12 As shown, the method provided by the embodiment of the present disclosure may include the following steps.

[0227] In step S1210, a first NAT parameter is obtained from the AF.

[0228] In step S1220, a target UPF / PSA is determined so that the target UPF / PSA reallocates UE target network address information to the UE and enables the UE to continue using the UE source network address information.

[0229] In an exemplary embodiment, the target UPF / PSA may also be used to allocate core network tunnel information. After determining the target protocol data unit session anchor user plane function UPF / PSA, the method may further include: obtaining the core network tunnel information from the target UPF / PSA; sending indication information to the target UPF / PSA to indicate that if the target UPF / PSA receives an uplink data packet from the UE before receiving the data transmission notification sent by the SMF, the target UPF / PSA buffers the uplink data packet; selecting a target UL CL / BP, and configuring the core network tunnel information for the target UL CL / BP and the wireless access network.

[0230] In step S1230, the first NAT parameter is sent to the target UPF / PSA so that the target UPF / PSA generates a second NAT parameter according to the first NAT parameter, the UE target network address information and the UE source network address information.

[0231] In step S1240, the second NAT parameter is received from the target UPF / PSA, and the target UPF / PSA is used to perform NAT conversion on the received data packet according to the second NAT parameter.

[0232] In step S1250, the second NAT parameter is passed to the AF so that the AF configures a third NAT parameter for the target AS according to the second NAT parameter and migrates the source AS to the target AS, and the target AS is used to perform NAT conversion on the data packet according to the third NAT parameter.

[0233] In an exemplary embodiment, after passing the NAT parameters to the AF, the method may further include: sending a data transmission notification to the target UPF / PSA to notify the target UPF / PSA to receive the uplink data packet sent by the UE through the target uplink classifier UL CL / BP, or to send a downlink data packet to the UE through the target UL CL / BP.

[0234] The specific implementation of the method for achieving communication continuity provided by the embodiment of the present disclosure can refer to the contents of the method for achieving communication continuity in other embodiments mentioned above, and will not be repeated here.

[0235] Fig.13A flowchart of a method for achieving communication continuity according to yet another embodiment of the present disclosure is schematically shown. Fig.13 The method provided in the embodiment can be applied to a user equipment UE, where the UE has established a connection with a source application server AS using the allocated UE source network address information. Fig.13 As shown, the method provided by the embodiment of the present disclosure may include the following steps.

[0236] In step S1310, an uplink data packet is transmitted to a target UPF / PSA so that the target UPF / PSA performs a first NAT conversion on the uplink data packet according to a second uplink NAT parameter, generates and sends an uplink data packet after the first NAT conversion to a target AS, and the target AS is used to perform a second NAT conversion on the uplink data packet after the first NAT conversion according to a third uplink NAT parameter.

[0237] In step S1320, a downlink data packet is received through the target UPF / PSA, wherein the target AS is used to perform a third NAT conversion on the downlink data packet according to a third downlink NAT parameter, and the target UPF / PSA is used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter.

[0238] The specific implementation of the method for achieving communication continuity provided by the embodiment of the present disclosure can refer to the contents of the method for achieving communication continuity in other embodiments mentioned above, and will not be repeated here.

[0239] Fig.14 The block diagram of the application function according to an embodiment of the present disclosure is schematically shown. Fig.14 As shown, an embodiment of the present disclosure provides an application function 1400, which may include: one or more processors 1401; a memory 1403, configured to store one or more programs, and when the one or more programs are executed by the one or more processors 1401, the one or more processors 1401 implement the method described in any of the above embodiments.

[0240] The user equipment UE corresponding to the application function 1400 has established a connection with the source application server AS using the allocated UE source network address information.

[0241] Among them, the program can be specifically used to: determine to migrate the source AS to the target AS; transmit a first NAT parameter to the SMF so that the SMF determines the target UPF / PSA, the target UPF / PSA is used to reallocate UE target network address information for the UE, and generate and return a second NAT parameter to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, and perform NAT conversion on the received data packet according to the second NAT parameter; obtain the second NAT parameter from the SMF; configure a third NAT parameter for the target AS according to the second NAT parameter, and migrate the source AS to the target AS, so that the target AS performs NAT conversion on the data packet according to the third NAT parameter.

[0242] Continue to refer Fig.14 , the program may include: an application server migration determination unit 14031, which can be used to determine whether to migrate the source AS to the target AS; a first NAT parameter transmission unit 14032, which can be used to transmit a first NAT parameter to the SMF so that the SMF determines a target UPF / PSA, the target UPF / PSA is used to reallocate UE target network address information for the UE, and generate and return a second NAT parameter to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, perform NAT conversion on the received data packet according to the second NAT parameter; obtain the second NAT parameter from the SMF; a second NAT parameter acquisition unit 14033, which can be used to obtain the second NAT parameter from the SMF; a third NAT parameter configuration unit 14034, which can be used to configure a third NAT parameter for the target AS according to the second NAT parameter, and migrate the source AS to the target AS, so that the target AS performs NAT conversion on the data packet according to the third NAT parameter.

[0243] In an exemplary embodiment, the application server migration determination unit 14031 may be configured to: receive an event open early notification message from the SMF; and determine to migrate the source AS to the target AS according to the event open early notification message.

[0244] In an exemplary embodiment, the application server migration determination unit 14031 may be configured to: receive a data impact early notification message from an NEF, wherein the NEF is configured to receive an event open early notification message from the SMF, and send the data impact early notification message to the AF according to the event open early notification message.

[0245] In an exemplary embodiment, the first NAT parameter may include target AS network address information of the target AS, and the target AS network address information may include a target AS IP address and a target AS port number.

[0246] In an exemplary embodiment, the first NAT parameter transmission unit 14032 may be configured to: send an event open application relocation message to the SMF, wherein the event open application relocation message carries the target AS IP address and the target AS port number.

[0247] In an exemplary embodiment, the first NAT parameter transmission unit 14032 can be configured to: send a data-affecting application relocation information message to the NEF, wherein the data-affecting application relocation information message carries the target AS IP address and the target AS port number, so that the NEF sends an event-opening application relocation message to the SMF, wherein the event-opening application relocation message carries the target AS IP address and the target AS port number.

[0248] In an exemplary embodiment, the first NAT parameter transmission unit 14032 can be configured to: send a policy authorization establishment / update request message to the policy control function PCF, wherein the policy authorization establishment / update request message carries the target AS IP address and the target AS port number of the target AS, so that the PCF sends a session management policy control update notification message to the SMF, wherein the session management policy control update notification message carries the target AS IP address and the target AS port number of the target AS.

[0249] In an exemplary embodiment, the data packet may include an uplink data packet sent by the UE, the second NAT parameter may include a second uplink NAT parameter, the target UPF / PSA may be used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter may include a third uplink NAT parameter, and the source AS network address information of the source AS may include a source AS IP address. Configuring the third NAT parameter for the target AS according to the second NAT parameter may include: generating the third uplink NAT parameter according to the second uplink NAT parameter.

[0250] In an exemplary embodiment, the target AS may include a middle box and an internal target AS, the middle box and the internal target AS are different network entities, communicating through a network connection, and the network address of the middle box is the target AS IP address. The third NAT parameter configuration unit 14034 may be configured to: configure the third uplink NAT parameter to the middle box, so that the middle box performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal target AS through the network connected to the internal target AS; use the source AS IP address of the source AS as the network address of the internal target AS, so that the internal target AS receives the uplink data packet from the middle box through the network connected to the middle box.

[0251] In an exemplary embodiment, the data packet may further include a downlink data packet, the second NAT parameter may further include a second downlink NAT parameter, and the third NAT parameter may further include a third downlink NAT parameter. The third NAT parameter configuration unit 14034 may further be configured to: generate the third downlink NAT parameter according to the second downlink NAT parameter; configure the third downlink NAT parameter to the middle box, so that the middle box performs a third NAT conversion on the downlink data packet sent by the internal target AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, and the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE.

[0252] In an exemplary embodiment, the target AS may include a first NAT middleware and an internal source AS. The third NAT parameter configuration unit 14034 may be configured to: configure the third uplink NAT parameter to the first NAT middleware, so that the first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal source AS; copy the entire image of the operating environment of the source AS to the internal source AS (making the network address of the internal source AS the source AS IP address), so that the internal source AS receives the uplink data packet through the first NAT middleware.

[0253] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, and the third NAT parameter may also include a third downlink NAT parameter. The third NAT parameter configuration unit 14034 may also be configured to: generate the third downlink NAT parameter according to the second downlink NAT parameter; configure the third downlink NAT parameter to the first NAT middleware, so that the first NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, and the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE.

[0254] In an exemplary embodiment, the target AS may include a target IP protocol stack and an internal source AS running program, and the target IP protocol stack includes a second NAT middleware. The third NAT parameter configuration unit 14034 may be configured to: send the third uplink NAT parameter to the target IP protocol stack so as to configure the third uplink NAT parameter to the second NAT middleware, and the second NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet whose destination address is the source AS IP address; copy the running program of the source AS to the target AS to obtain the internal source AS running program, and the internal source AS running program is used as the running program of the source AS (making the network address of the target IP protocol stack the target AS IP address), so that the internal source AS running program receives the uplink data packet whose destination address is the source AS IP address from the target IP protocol stack.

[0255] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, and the third NAT parameter may also include a third downlink NAT parameter. The third NAT parameter configuration unit 14034 may also be configured to: generate the third downlink NAT parameter according to the second downlink NAT parameter; send the third downlink NAT parameter to the target IP protocol stack so as to configure the third downlink NAT parameter to the second NAT middleware, the second NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS running program according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE.

[0256] In an exemplary embodiment, the UE source network address information may include a UE source IP address and a source UE port number, the UE target network address information may include a UE target IP address and a target UE port number, and the source AS network address information may further include a source AS port number. Among them, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination address from the source AS IP address to the target AS IP address; the third uplink NAT parameter can be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination address from the target AS IP address to the source AS IP address; or, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter can be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination address from the target AS IP address to the source AS IP address, the destination port is converted from the target AS port number to the source AS port number; or, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address is converted from the source AS IP address to the target AS IP address, and the source port is converted from the source UE port number to the target UE port number; the third uplink NAT parameter can be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address is converted from the target AS IP address to the source ASIP address, and the source port is converted from the target UE port number to the source UE port number; or, the second uplink NAT parameter can be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address is converted from the source ASIP address to the target AS IP address, the source port is converted from the source UE port number to the target UE port number, and the destination port is converted from the source AS port number to the target AS port number;The third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, the source port from the target UE port number to the source UE port number, and the destination port from the target AS port number to the source AS port number; or, the second uplink NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination port from the target AS port number to the source AS port number. port number; or, the second uplink NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the source port from the source UE port number to the target UE port number, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter may be used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the source port from the target UE port number to the source UE port number, and the destination port from the target AS port number to the source AS port number. ;

[0257] In an exemplary embodiment, the UE source network address information may include a UE source IP address and a source UE port number, the UE target network address information may include a UE target IP address and a target UE port number, and the source AS network address information may also include a source AS port number. The third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, and the destination address from the UE source IP address to the UE target IP address; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination address from the UE target IP address to the UE source IP address; or, the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination address from the UE target IP address to the UE source IP address. The third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, and the source port from the source AS port number of the source AS to the target AS port number of the target AS; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, and the source port from the target AS port number to the source AS port number; or the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE source IP address, and the source port from the target AS port number to the source AS port number;The second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, the source port from the target AS port number to the source AS port number, and the destination port from the target UE port number to the source UE port number; or, the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS IP address, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination port from the target UE port number to the source UE port number; or, the third downstream NAT parameter may be used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS The second downstream NAT parameter may be used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the source port from the target AS port number to the source AS port number, and the destination port from the target UE port number to the source UE port number. ;

[0258] The specific implementation of each unit in the application function provided by the embodiment of the present disclosure can refer to the content of the above-mentioned method for realizing communication continuity, which will not be repeated here.

[0259] Fig.15 Schematically shows a block diagram of a target application server according to an embodiment of the present disclosure. Fig.15 As shown, the target application server 1500 may include: one or more processors 1501; a memory 1503, configured to store one or more programs, and when the one or more programs are executed by the one or more processors 1501, the one or more processors 1501 implement the method described in any of the above embodiments.

[0260] Among them, the program can be specifically used to: use AF to configure the third NAT parameter to migrate the source AS to the target AS, and the third NAT parameter is generated according to the second NAT parameter of the target UPF / PSA; obtain a data packet, wherein the data packet is a data packet generated by the target UPF / PSA after NAT conversion according to the second NAT parameter or a data packet generated by the target AS; perform NAT conversion on the data packet according to the third NAT parameter; if the data packet is a data packet generated by the target AS, the data packet after NAT conversion according to the third NAT parameter is sent to the target UPF / PSA, so that the target UPF / PSA performs NAT conversion again according to the second NAT parameter.

[0261] Continue to refer Fig.15 The program may further include: a third NAT parameter configuration unit 15031, which can be used to configure a third NAT parameter using AF to migrate the source AS to the target AS, and the third NAT parameter is generated according to the second NAT parameter of the target UPF / PSA; a data packet acquisition unit 15032, which can be used to acquire a data packet, wherein the data packet is a data packet generated by the target UPF / PSA after NAT conversion according to the second NAT parameter or a data packet generated by the target AS; a NAT conversion unit 15033, which can be used to perform NAT conversion on the data packet according to the third NAT parameter; a data packet sending unit 15034, which can be used to send the data packet after NAT conversion according to the third NAT parameter to the target UPF / PSA if the data packet is a data packet generated by the target AS, so that the target UPF / PSA performs NAT conversion again according to the second NAT parameter.

[0262] In an exemplary embodiment, the data packet may include an uplink data packet sent by the UE, the second NAT parameter may include a second uplink NAT parameter, the target UPF / PSA may be used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter may include a third uplink NAT parameter, the source AS network address information of the source AS may include a source AS IP address, and the AF may be used to generate the third uplink NAT parameter based on the second uplink NAT parameter.

[0263] In an exemplary embodiment, the target AS may include a middle box and an internal target AS, the middle box and the internal target AS are different network entities, communicating through a network connection, and the network address of the middle box is the target AS IP address of the target AS. The third NAT parameter configuration unit 15031 may be configured as follows: the middle box obtains the third uplink NAT parameter from the AF; and uses the source AS IP address of the source AS as the network address of the internal target AS through the AF. The NAT conversion unit 15033 may be configured as follows: the middle box receives an uplink data packet after a first NAT conversion from the target UPF / PSA; the middle box performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; and the middle box sends the uplink data packet to the internal target AS through a network connected to the internal target AS.

[0264] In an exemplary embodiment, the data packet may further include a downlink data packet, the second NAT parameter may further include a second downlink NAT parameter, the third NAT parameter may further include a third downlink NAT parameter, and the AF may further be used to generate the third downlink NAT parameter according to the second downlink NAT parameter. The third NAT parameter configuration unit 15031 may further be configured as follows: the middle box obtains the third downlink NAT parameter from the AF. The NAT conversion unit 15033 may further be configured as follows: the internal target AS sends the downlink data packet to the middle box; the middle box performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the middle box sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE.

[0265] In an exemplary embodiment, the target AS may include a first NAT middleware and an internal source AS. The third NAT parameter configuration unit 15031 may be configured as follows: the first NAT middleware obtains the third uplink NAT parameter from the AF; copies the entire image of the operating environment of the source AS to the internal source AS through the AF (making the network address of the internal source AS the source AS IP address). The NAT conversion unit 15033 may be configured as follows: the first NAT middleware receives the uplink data packet after the first NAT conversion from the target UPF / PSA; the first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; the first NAT middleware sends the uplink data packet to the internal source AS.

[0266] The data packet also includes a downlink data packet, the second NAT parameter also includes a second downlink NAT parameter, the third NAT parameter also includes a third downlink NAT parameter, and the AF is also used to generate the third downlink NAT parameter according to the second downlink NAT parameter. The third NAT parameter configuration unit 15031 can also be configured as: the first NAT middleware obtains the third downlink NAT parameter from the AF. The NAT conversion unit 15033 can also be configured as: the internal source AS sends the downlink data packet to the first NAT middleware; the first NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the first NAT middleware sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE.

[0267] In an exemplary embodiment, the target AS may include a target IP protocol stack and an internal source AS running program, and the target IP protocol stack includes a second NAT middleware. The third NAT parameter configuration unit 15031 may be configured as follows: the target IP protocol stack obtains the third uplink NAT parameter from the AF; the target IP protocol stack configures the third uplink NAT parameter to the second NAT middleware; the running program of the source AS is copied to the target AS through the AF to obtain the internal source AS running program, and the internal source AS running program is used as the running program of the source AS (making the network address of the target IP protocol stack the target AS IP address). The NAT conversion unit 15033 may be configured as follows: the target IP protocol stack receives an uplink data packet after the first NAT conversion from the target UPF / PSA; the second NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet whose destination address is the source AS IP address; the target IP protocol stack sends the uplink data packet whose destination address is the source AS IP address to the internal source AS running program.

[0268] In an exemplary embodiment, the data packet may also include a downlink data packet, the second NAT parameter may also include a second downlink NAT parameter, the third NAT parameter may also include a third downlink NAT parameter, and the AF may also be used to generate the third downlink NAT parameter according to the second downlink NAT parameter. The third NAT parameter configuration unit 15031 may also be configured as follows: the target IP protocol stack obtains the third downlink NAT parameter from the AF; the target IP protocol stack configures the third downlink NAT parameter to the second NAT middleware. The NAT conversion unit 15033 may also be configured as follows: the internal source AS runs a program to send a downlink data packet to the target IP protocol stack; the second NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; the target IP protocol stack sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE.

[0269] The specific implementation of each unit in the target application server provided by the embodiment of the present disclosure may refer to the content of the above-mentioned method for realizing communication continuity, which will not be repeated here.

[0270] Fig.16 A block diagram of a session management function according to an embodiment of the present disclosure is schematically shown. Fig.16As shown, the session management function 1600 may include: one or more processors 1601; a memory 1603, configured to store one or more programs, and when the one or more programs are executed by the one or more processors 1601, the one or more processors 1601 implement the method described in any of the above embodiments.

[0271] Among them, the UE corresponding to the session management function 1600 has established a connection with the source application server AS using the allocated UE source network address information.

[0272] Among them, the program can be specifically used to: obtain a first NAT parameter from the AF; determine a target UPF / PSA so that the target UPF / PSA reallocates UE target network address information for the UE and enables the UE to continue to use the UE source network address information; send the first NAT parameter to the target UPF / PSA so that the target UPF / PSA generates a second NAT parameter based on the first NAT parameter, the UE target network address information and the UE source network address information; receive the second NAT parameter from the target UPF / PSA, and the target UPF / PSA is used to perform NAT conversion on the received data packet according to the second NAT parameter; pass the second NAT parameter to the AF, so that the AF configures a third NAT parameter for the target AS according to the second NAT parameter, and migrates the source AS to the target AS, and the target AS is used to perform NAT conversion on the data packet according to the third NAT parameter.

[0273] Continue to refer Fig.16The program may further include: a first NAT parameter acquiring unit 16031, which can be used to acquire a first NAT parameter from the AF; a target UPF / PSA determining unit 16032, which can be used to determine a target UPF / PSA, so that the target UPF / PSA reallocates UE target network address information to the UE and enables the UE to continue to use the UE source network address information; a first NAT parameter sending unit 16033, which can be used to send the first NAT parameter to the target UPF / PSA, so that the target UPF / PSA determines the first NAT parameter based on the first NAT parameter, the UE target network address information and the UE source network address information. The second NAT parameter is generated based on the network address information; the second NAT parameter receiving unit 16034 can be used to receive the second NAT parameter from the target UPF / PSA, and the target UPF / PSA is used to perform NAT conversion on the received data packet according to the second NAT parameter; the second NAT parameter passing unit 16035 can be used to pass the second NAT parameter to the AF, so that the AF configures the third NAT parameter for the target AS according to the second NAT parameter and migrates the source AS to the target AS, and the target AS is used to perform NAT conversion on the data packet according to the third NAT parameter.

[0274] In an exemplary embodiment, the target UPF / PSA can also be used to allocate core network tunnel information. The program may also include: a core network tunnel information acquisition unit, which can be used to acquire the core network tunnel information from the target UPF / PSA after determining the target UPF / PSA; an indication information sending unit, which can be used to send indication information to the target UPF / PSA to indicate that if the target UPF / PSA receives an uplink data packet from the UE before receiving the data transmission notification sent by the SMF, the target UPF / PSA buffers the uplink data packet; an uplink classifier selection unit, which can be used to select a target uplink classifier UL CL / BP and configure the core network tunnel information for the target UL CL / BP and the wireless access network.

[0275] In an exemplary embodiment, the program may also include: a data transmission notification sending unit, which can be used to send a data transmission notification to the target UPF / PSA after passing the second NAT parameter to the AF, so as to notify the target UPF / PSA to receive the uplink data packet sent by the UE through the target UL CL / BP, or to send a downlink data packet to the UE through the target UL CL / BP.

[0276] The specific implementation of each unit in the session management function provided by the embodiment of the present disclosure can refer to the content of the above-mentioned method for realizing communication continuity, which will not be repeated here.

[0277] Fig.17 A block diagram of a user equipment according to an embodiment of the present disclosure is schematically shown. Fig.17 As shown, the user equipment 1700 may include: one or more processors 1701; a memory 1703, configured to store one or more programs, and when the one or more programs are executed by the one or more processors 1701, the one or more processors 1701 implement the method as described in any of the above embodiments. The UE has established a connection with the source application server AS using the allocated UE source network address information.

[0278] Among them, the program can be specifically used to: transmit an uplink data packet to a target UPF / PSA, so that the target UPF / PSA performs a first NAT conversion on the uplink data packet according to a second uplink NAT parameter, generates and sends an uplink data packet after the first NAT conversion to a target AS, and the target AS is used to perform a second NAT conversion on the uplink data packet after the first NAT conversion according to a third uplink NAT parameter; receive a downlink data packet through the target UPF / PSA, wherein the target AS is used to perform a third NAT conversion on the downlink data packet according to a third downlink NAT parameter, and the target UPF / PSA is used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter.

[0279] refer to Fig.17 The program may further include: an uplink data packet transmission unit 17031, which can be used to transmit an uplink data packet to a target UPF / PSA, so that the target UPF / PSA performs a first NAT conversion on the uplink data packet according to a second uplink NAT parameter, generates and sends an uplink data packet after the first NAT conversion to a target AS, and the target AS performs a second NAT conversion on the uplink data packet after the first NAT conversion according to a third uplink NAT parameter; a downlink data packet receiving unit 17032, which can be used to receive a downlink data packet through the target UPF / PSA, wherein the target AS performs a third NAT conversion on the downlink data packet according to a third downlink NAT parameter, and the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter.

[0280] The specific implementation of each unit in the user equipment provided by the embodiment of the present disclosure can refer to the content of the above-mentioned method for achieving communication continuity, which will not be repeated here.

[0281] It should be noted that, referring to the above Fig.14 , Fig.15 , Fig.16 and Fig.17, which shows a structural diagram of an application function 1400, a target application server 1500, a session management function 1600 and a user device 1700 suitable for implementing an embodiment of the present application. Fig.14 , Fig.15 , Fig.16 and Fig.17 The structure shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0282] Reference Fig.14 , Fig.15 , Fig.16 and Fig.17 The application function 1400, target application server 1500, session management function 1600 and user equipment 1700 provided by the embodiment of the present disclosure may also respectively include: a communication interface (1402, 1502, 1602, 1702) and a communication bus (1404, 1504, 1604, 1704).

[0283] The processors (1401, 1501, 1601, 1701), the communication interfaces (1402, 1502, 1602, 1702) and the memories (1403, 1503, 1603, 1703) communicate with each other via the communication buses (1404, 1504, 1604, 1704).

[0284] Optionally, the communication interface (1402, 1502, 1602, 1702) may be an interface of a communication module, such as an interface of a GSM (Global System for Mobile communications) module. The processor 1301 is used to execute a program. The memory (1403, 1503, 1603, 1703) is used to store a program. The program may include a computer program, and the computer program includes computer operation instructions.

[0285] The processor (1401, 1501, 1601, 1701) may be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present disclosure.

[0286] The memory (1403, 1503, 1603, 1703) may include a high-speed RAM (random access memory) memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0287] 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 units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided into multiple units to be embodied.

[0288] Through the description of the above implementation, it is easy for those skilled in the art to understand that the example implementation described here can be implemented by software, or by software combined with necessary hardware. Therefore, the technical solution according to the implementation of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, a server, a touch terminal, or a network device, etc.) to execute the method according to the implementation of the present disclosure.

[0289] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0290] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for achieving communication continuity, characterized in that: Applied to an AF corresponding to a UE, the UE having established a connection with a source AS using the allocated UE source network address information; wherein the method comprises: Determine to migrate the source AS to a target AS; Transmitting a first NAT parameter to the SMF so that the SMF determines a target UPF / PSA, the target UPF / PSA is used to reallocate UE target network address information for the UE, and generating and returning a second NAT parameter to the SMF based on the first NAT parameter, the UE source network address information and the UE target network address information, and performing NAT conversion on the received data packet according to the second NAT parameter; Acquire the second NAT parameter from the SMF; Configure a third NAT parameter for the target AS according to the second NAT parameter, and migrate the source AS to the target AS, so that the target AS performs NAT conversion on the data packet according to the third NAT parameter. The data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the data packet obtained by the target AS remain unchanged with the source address and destination address sent by the UE, or the source address and destination address of the data packet obtained by the UE remain unchanged with the source address and destination address sent by the target AS.

2. The method according to claim 1, characterized in that: Determining to migrate the source AS to the target AS includes: Receiving an event open early notification message from the SMF; According to the event open early notification message, it is determined to migrate the source AS to the target AS.

3. The method according to claim 1, characterized in that Determining to migrate the source AS to the target AS includes: A data impact early notification message is received from the NEF, wherein the NEF is used to receive an event open early notification message from the SMF, and send the data impact early notification message to the AF according to the event open early notification message.

4. The method according to claim 1, characterized in that The first NAT parameter includes target AS network address information of the target AS, and the target AS network address information includes a target AS IP address and a target AS port number; wherein transmitting the first NAT parameter to the SMF includes: An event open application relocation message is sent to the SMF, where the event open application relocation message carries the target AS IP address and the target AS port number.

5. The method according to claim 1, characterized in that: The first NAT parameter includes target AS network address information of the target AS, and the target AS network address information includes a target AS IP address and a target AS port number; wherein transmitting the first NAT parameter to the SMF includes: A data-affecting application relocation information message is sent to NEF, wherein the data-affecting application relocation information message carries the target AS IP address and the target AS port number, so that the NEF sends an event-opening application relocation message to the SMF, wherein the event-opening application relocation message carries the target AS IP address and the target AS port number.

6. The method according to claim 1, characterized in that The first NAT parameter includes target AS network address information of the target AS, and the target AS network address information includes a target AS IP address and a target AS port number; wherein transmitting the first NAT parameter to the SMF includes: A policy authorization establishment / update request message is sent to the PCF, where the policy authorization establishment / update request message carries the target AS IP address and the target AS port number, so that the PCF sends a session management policy control update notification message to the SMF, where the session management policy control update notification message carries the target AS IP address and the target AS port number.

7. The method according to any one of claims 4 to 6, characterized in that: The data packet includes an uplink data packet sent by the UE, the second NAT parameter includes a second uplink NAT parameter, the target UPF / PSA is used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter includes a third uplink NAT parameter, and the source AS network address information of the source AS includes a source AS IP address; The step of configuring a third NAT parameter for the target AS according to the second NAT parameter includes: The third upstream NAT parameter is generated according to the second upstream NAT parameter.

8. The method according to claim 7, characterized in that The target AS includes an intermediate box and an internal target AS, the intermediate box and the internal target AS are different network entities, and communicate through a network connection, and the network address of the intermediate box is the target AS IP address; wherein, configuring a third NAT parameter for the target AS according to the second NAT parameter, and migrating the source AS to the target AS, comprises: Configuring the third uplink NAT parameter to the middle box, so that the middle box performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal target AS through a network connected to the internal target AS; The source AS IP address of the source AS is used as the network address to the internal target AS, so that the internal target AS receives the uplink data packet from the middle box through the network connected to the middle box.

9. The method according to claim 8, characterized in that The data packet also includes a downlink data packet, the second NAT parameter also includes a second downlink NAT parameter, and the third NAT parameter also includes a third downlink NAT parameter; wherein the third NAT parameter is configured for the target AS according to the second NAT parameter, and the source AS is migrated to the target AS, and further includes: generating the third downstream NAT parameter according to the second downstream NAT parameter; The third downlink NAT parameter is configured to the middle box body, so that the middle box body performs a third NAT conversion on the downlink data packet sent by the internal target AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA, and the target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtain and send the downlink data packet to the UE.

10. The method according to claim 7, characterized in that The target AS includes a first NAT middleware and an internal source AS; wherein configuring a third NAT parameter for the target AS according to the second NAT parameter and migrating the source AS to the target AS includes: Configuring the third uplink NAT parameter to the first NAT middleware, so that the first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter, obtains the uplink data packet, and sends the uplink data packet to the internal source AS; The entire image of the operating environment of the source AS is copied to the internal source AS, so that the internal source AS receives the uplink data packet through the first NAT middleware.

11. The method according to claim 10, characterized in that The data packet also includes a downlink data packet, the second NAT parameter also includes a second downlink NAT parameter, and the third NAT parameter also includes a third downlink NAT parameter; wherein the third NAT parameter is configured for the target AS according to the second NAT parameter, and the source AS is migrated to the target AS, and further includes: generating the third downstream NAT parameter according to the second downstream NAT parameter; The third downlink NAT parameter is configured to the first NAT middleware, so that the first NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA. The target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, and obtain and send the downlink data packet to the UE.

12. The method according to claim 7, characterized in that The target AS includes a target IP protocol stack and an internal source AS running program, and the target IP protocol stack includes a second NAT middleware; wherein, configuring a third NAT parameter for the target AS according to the second NAT parameter, and migrating the source AS to the target AS, comprises: Sending the third uplink NAT parameter to the target IP protocol stack so as to configure the third uplink NAT parameter to the second NAT middleware, and the second NAT middleware performing a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet whose destination address is the source AS IP address; The running program of the source AS is copied to the target AS to obtain the internal source AS running program, and the internal source AS running program serves as the running program of the source AS, so that the internal source AS running program receives the uplink data packet whose destination address is the source AS IP address from the target IP protocol stack.

13. The method according to claim 12, characterized in that The data packet also includes a downlink data packet, the second NAT parameter also includes a second downlink NAT parameter, and the third NAT parameter also includes a third downlink NAT parameter; wherein the third NAT parameter is configured for the target AS according to the second NAT parameter, and the source AS is migrated to the target AS, and further includes: generating the third downstream NAT parameter according to the second downstream NAT parameter; The third downlink NAT parameter is sent to the target IP protocol stack so that the third downlink NAT parameter is configured to the second NAT middleware. The second NAT middleware performs a third NAT conversion on the downlink data packet sent by the internal source AS running program according to the third downlink NAT parameter, and sends the downlink data packet after the third NAT conversion to the target UPF / PSA. The target UPF / PSA is also used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, and obtain and send the downlink data packet to the UE.

14. The method according to claim 7, characterized in that The UE source network address information includes the UE source IP address and the source UE port number, the UE target network address information includes the UE target IP address and the target UE port number, and the source AS network address information also includes the source AS port number; wherein, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination address from the source AS IP address to the target AS IP address; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination address from the target AS IP address to the source AS IP address; or, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, and the destination port from the target AS port number to the source AS port number; or, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, and the source port from the source UE port number to the target UE port number; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, and the source port from the target UE port number to the source UE port number; or, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the destination address from the source AS IP address to the target AS IP address, the source port from the source UE port number to the target UE port number, and the destination port from the source AS port number to the target AS port number; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the destination address from the target AS IP address to the source AS IP address, the source port from the target UE port number to the source UE port number, and the destination port from the target AS port number to the source AS port number; or, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, and the destination port is converted from the source AS port number to the target AS port number; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, and the destination port is converted from the target AS port number to the source AS port number; or, The second uplink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the uplink data packet from the UE source IP address to the UE target IP address, the source port is converted from the source UE port number to the target UE port number, and the destination port is converted from the source AS port number to the target AS port number; the third uplink NAT parameter is used to instruct the target AS to convert the source address of the uplink data packet after the first NAT conversion from the UE target IP address to the UE source IP address, the source port is converted from the target UE port number to the source UE port number, and the destination port is converted from the target AS port number to the source AS port number.

15. The method according to any one of claims 9, 11 or 13, characterized in that: The UE source network address information includes the UE source IP address and the source UE port number, the UE target network address information includes the UE target IP address and the target UE port number, and the source AS network address information also includes the source AS port number; wherein, The third downlink NAT parameter is used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, and the destination address from the UE source IP address to the UE target IP address; the second downlink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination address from the UE target IP address to the UE source IP address; or, The third downstream NAT parameter is used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, and the destination port from the target UE port number to the source UE port number; or, The third downstream NAT parameter is used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, and the source port from the source AS port number of the source AS to the target AS port number of the target AS; the second downstream NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, and the source port from the target AS port number to the source AS port number; or, The third downstream NAT parameter is used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS IP address, the destination address from the UE source IP address to the UE target IP address, the source port from the source AS port number of the source AS to the target AS port number of the target AS, and the destination port from the source UE port number to the target UE port number; the second downstream NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the destination address from the UE target IP address to the UE source IP address, the source port from the target AS port number to the source AS port number, and the destination port from the target UE port number to the source UE port number; or, The third downlink NAT parameter is used to instruct the target AS to convert the source address of the downlink data packet from the source AS IP address to the target AS IP address, and the destination port is converted from the source UE port number to the target UE port number; the second downlink NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downlink data packet after the third NAT conversion from the target AS IP address to the source AS IP address, and the destination port is converted from the target UE port number to the source UE port number; or, The third downstream NAT parameter is used to instruct the target AS to convert the source address of the downstream data packet from the source AS IP address to the target AS IP address, the source port is converted from the source AS port number of the source AS to the target AS port number of the target AS, and the destination port is converted from the source UE port number to the target UE port number; the second downstream NAT parameter is used to instruct the target UPF / PSA to convert the source address of the downstream data packet after the third NAT conversion from the target AS IP address to the source AS IP address, the source port is converted from the target AS port number to the source AS port number, and the destination port is converted from the target UE port number to the source UE port number.

16. A method for achieving communication continuity, characterized in that: Applied to a target AS; wherein the method comprises: Utilizing AF to configure a third NAT parameter, the source AS is migrated to the target AS, the third NAT parameter is generated according to the second NAT parameter of the target UPF / PSA, wherein before the AF configures the third NAT parameter, the UE has established a connection with the source AS using the allocated UE source network address information; the target UPF / PSA is used to reallocate UE target network address information for the UE, and generate the second NAT parameter according to the first NAT parameter, the UE source network address information, and the UE target network address information; Acquire a data packet, wherein the data packet is a data packet generated by the target UPF / PSA after performing NAT conversion according to the second NAT parameter or a data packet generated by the target AS; Performing NAT conversion on the data packet according to the third NAT parameter; If the data packet is a data packet generated by the target AS, the data packet after NAT conversion according to the third NAT parameter will be sent to the target UPF / PSA, so that the target UPF / PSA will perform NAT conversion again according to the second NAT parameter. The data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the data packet obtained by the target AS remain unchanged with the source address and destination address sent by the UE, or the source address and destination address of the data packet obtained by the UE remain unchanged with the source address and destination address sent by the target AS.

17. The method according to claim 16, characterized in that The data packet includes an uplink data packet sent by the UE, the second NAT parameter includes a second uplink NAT parameter, the target UPF / PSA is used to perform a first NAT conversion on the uplink data packet according to the second uplink NAT parameter, the third NAT parameter includes a third uplink NAT parameter, the source AS network address information of the source AS includes a source AS IP address, and the AF is used to generate the third uplink NAT parameter according to the second uplink NAT parameter.

18. The method according to claim 17, characterized in that The target AS includes an intermediate box and an internal target AS, the intermediate box and the internal target AS are different network entities, and communicate through a network connection, and the network address of the intermediate box is the target AS IP address of the target AS; wherein, using AF to configure the third NAT parameter to migrate the source AS to the target AS includes: The middle box obtains the third uplink NAT parameter from the AF; Using the source AS IP address of the source AS as the network address of the internal target AS through the AF; The step of performing NAT conversion on the data packet according to the third NAT parameter includes: The middle box receives the uplink data packet after the first NAT conversion from the target UPF / PSA; The intermediate box performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; The middle box sends the uplink data packet to the internal target AS through a network connected to the internal target AS.

19. The method according to claim 18, characterized in that The data packet further includes a downlink data packet, the second NAT parameter further includes a second downlink NAT parameter, the third NAT parameter further includes a third downlink NAT parameter, and the AF is further used to generate the third downlink NAT parameter according to the second downlink NAT parameter; wherein configuring the third NAT parameter using the AF further includes: The middle box obtains the third downstream NAT parameter from the AF; Wherein, performing NAT conversion on the data packet according to the third NAT parameter further includes: The internal target AS sends the downlink data packet to the middle box; The intermediate box performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; The middle box sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, obtains and sends the downlink data packet to the UE.

20. The method according to claim 17, characterized in that The target AS includes a first NAT middleware and an internal source AS; wherein, using AF to configure a third NAT parameter to migrate the source AS to the target AS includes: The first NAT middleware obtains the third uplink NAT parameter from the AF; Copying the entire image of the operating environment of the source AS to the internal source AS through the AF; The step of performing NAT conversion on the data packet according to the third NAT parameter includes: The first NAT middleware receives an uplink data packet after the first NAT conversion from the target UPF / PSA; The first NAT middleware performs a second NAT conversion on the uplink data packet after the first NAT conversion according to the third uplink NAT parameter to obtain the uplink data packet; The first NAT middleware sends the uplink data packet to the internal source AS.

21. The method according to claim 20, characterized in that The data packet further includes a downlink data packet, the second NAT parameter further includes a second downlink NAT parameter, the third NAT parameter further includes a third downlink NAT parameter, and the AF is further used to generate the third downlink NAT parameter according to the second downlink NAT parameter; wherein configuring the third NAT parameter using the AF further includes: The first NAT middleware obtains the third downlink NAT parameter from the AF; Wherein, performing NAT conversion on the data packet according to the third NAT parameter further includes: The internal source AS sends the downlink data packet to the first NAT middleware; The first NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; The first NAT middleware sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameters, obtains and sends the downlink data packet to the UE.

22. The method according to claim 17, characterized in that The target AS includes a target IP protocol stack and an internal source AS running program, and the target IP protocol stack includes a second NAT middleware; wherein, using AF to configure a third NAT parameter to migrate the source AS to the target AS includes: The target IP protocol stack obtains the third uplink NAT parameter from the AF; The target IP protocol stack configures the third uplink NAT parameter to the second NAT middleware; Copying the operating program of the source AS to the target AS through the AF to obtain the internal source AS operating program, and the internal source AS operating program serves as the operating program of the source AS; The step of performing NAT conversion on the data packet according to the third NAT parameter includes: The target IP protocol stack receives the uplink data packet after the first NAT conversion from the target UPF / PSA; The second NAT middleware performs a second NAT conversion on the uplink data packet converted by the first NAT according to the third uplink NAT parameter to obtain the uplink data packet whose destination address is the source AS IP address; The target IP protocol stack sends the uplink data packet whose destination address is the source AS IP address to the internal source AS running program.

23. The method according to claim 22, characterized in that The data packet further includes a downlink data packet, the second NAT parameter further includes a second downlink NAT parameter, the third NAT parameter further includes a third downlink NAT parameter, and the AF is further used to generate the third downlink NAT parameter according to the second downlink NAT parameter; wherein configuring the third NAT parameter using the AF further includes: The target IP protocol stack obtains the third downstream NAT parameter from the AF; The target IP protocol stack configures the third downstream NAT parameter to the second NAT middleware; Wherein, performing NAT conversion on the data packet according to the third NAT parameter further includes: The internal source AS runs a program to send a downlink data packet to the target IP protocol stack; The second NAT middleware performs a third NAT conversion on the downlink data packet according to the third downlink NAT parameter; The target IP protocol stack sends the downlink data packet after the third NAT conversion to the target UPF / PSA, so that the target UPF / PSA performs a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameters, obtains and sends the downlink data packet to the UE.

24. A method for achieving communication continuity, characterized in that: Applied to the SMF corresponding to the UE, the UE has established a connection with the source AS using the allocated UE source network address information; wherein the method comprises: Obtain the first NAT parameter from AF; Determine a target UPF / PSA so that the target UPF / PSA reallocates UE target network address information for the UE and enables the UE to continue to use the UE source network address information; Sending the first NAT parameter to the target UPF / PSA so that the target UPF / PSA generates a second NAT parameter according to the first NAT parameter, the UE target network address information and the UE source network address information; receiving the second NAT parameter from the target UPF / PSA, the target UPF / PSA being configured to perform NAT conversion on the received data packet according to the second NAT parameter; The second NAT parameter is passed to the AF so that the AF configures a third NAT parameter for the target AS according to the second NAT parameter, and migrates the source AS to the target AS, the target AS is used to perform NAT conversion on the data packet according to the third NAT parameter, and the data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the data packet obtained by the target AS remain unchanged with the source address and destination address sent by the UE, or the source address and destination address of the data packet obtained by the UE remain unchanged with the source address and destination address sent by the target AS.

25. The method according to claim 24, characterized in that The target UPF / PSA is also used to allocate core network tunnel information; wherein, after determining the target UPF / PSA, the method further includes: Obtain the core network tunnel information from the target UPF / PSA; Sending indication information to the target UPF / PSA to indicate that if the target UPF / PSA receives an uplink data packet from the UE before receiving the data transmission notification sent by the SMF, the target UPF / PSA buffers the uplink data packet; A target UL CL / BP is selected, and the core network tunnel information is configured for the target UL CL / BP and the wireless access network.

26. The method according to claim 24 or 25, characterized in that After transmitting the second NAT parameter to the AF, the method further includes: Send a data transmission notification to the target UPF / PSA to notify the target UPF / PSA to receive the uplink data packet sent by the UE through the target UL CL / BP, or to send a downlink data packet to the UE through the target UL CL / BP.

27. A method for achieving communication continuity, characterized in that: Applied to a UE, the UE has established a connection with a source AS using the allocated UE source network address information; wherein the method comprises: Transmitting an uplink data packet to a target UPF / PSA so that the target UPF / PSA performs a first NAT conversion on the uplink data packet according to a second uplink NAT parameter, generates and sends an uplink data packet after the first NAT conversion to a target AS, the target AS is used to perform a second NAT conversion on the uplink data packet after the first NAT conversion according to a third uplink NAT parameter, and the uplink data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the uplink data packet obtained by the target AS remain unchanged from the source address and destination address sent by the UE; Receiving a downlink data packet through the target UPF / PSA, wherein the target AS is used to perform a third NAT conversion on the downlink data packet according to a third downlink NAT parameter, and the target UPF / PSA is used to perform a fourth NAT conversion on the downlink data packet after the third NAT conversion according to the second downlink NAT parameter, and the downlink data packet undergoes two NAT conversions by the target UPF / PSA and the target AS, so that the source address and destination address of the downlink data packet obtained by the UE remain unchanged from the source address and destination address sent by the target AS; The target UPF / PSA is used to reallocate UE target network address information for the UE, and generate a second NAT parameter according to the first NAT parameter, the UE source network address information and the UE target network address information, wherein the second NAT parameter includes the second uplink NAT parameter and the second downlink NAT parameter; The AF is used to configure third NAT parameters for the target AS according to the second NAT parameters, where the third NAT parameters include the third uplink NAT parameters and the third downlink NAT parameters.

28. An application function network element, characterized in that: include: one or more processors; The memory is 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 implement the method according to any one of claims 1 to 15.

29. A target application server, characterized in that: include: one or more processors; The memory is 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 implement the method according to any one of claims 16 to 23.

30. A session management function network element, characterized in that: include: one or more processors; The memory is 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 implement the method as claimed in any one of claims 24 to 26.

31. A user equipment, characterized in that: include: one or more processors; The memory is configured to store one or more programs, which, when executed by the one or more processors, enable the one or more processors to implement the method according to claim 27.

32. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 15, the method according to any one of claims 16 to 23, the method according to any one of claims 24 to 26, or the method according to claim 27 is implemented.

33. A computer program product comprising computer instructions, characterized in that: The computer program, when executed, implements the method of any one of claims 1 to 15, or the method of any one of claims 16 to 23, or the method of any one of claims 24 to 26, or the method of claim 27.

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