CN109818766B

CN109818766B - Communication method, network function entity, network function storage and computer readable storage medium

Info

Publication number: CN109818766B
Application number: CN201711163398.0A
Authority: CN
Inventors: 蒋栋栋; 丁学新; 刘俊羿; 郑芳庭; 翟义强
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2017-11-21
Filing date: 2017-11-21
Publication date: 2022-08-16
Anticipated expiration: 2037-11-21
Also published as: CN109818766A

Abstract

The invention provides a communication method, wherein the communication method comprises the following steps: when a context updating request sent by a first NF is received, UE context information stored in advance by a fault NF in a backup relation is acquired from a designated memory; still another communication method includes: registering the mutual backup relationship between the NF and one or more NF; when a fault NF exists, determining a standby NF for taking over the fault NF service; still another method of communication includes: and changing the state information of the fault NF according to the received state change notification event, recording the standby NF of the fault NF, and sending a context updating request to the standby NF. When receiving the session modifying request, the first NF carries out the session request through the standby NF of the fault NF, recovers the UE context information and carries out the telephone traffic migration.

Description

Communication method, network function entity, network function storage and computer readable storage medium

Technical Field

The present disclosure relates to the field of mobile communications technologies, and in particular, to a communication method, a network Function entity nf (network Function), a network Function repository nrf (network Function repeatability), and a computer-readable storage medium.

Background

In a conventional mobile communication system, when a certain network element fails or restarts, in order to ensure integrity and consistency of data, other network elements are usually triggered to delete local context data, or a UE is triggered to re-attach to ensure integrity or consistency of data.

Evolution typePacket Core network EPC (evolved Packet Core network) in the third Generation partnership project 3GPP (3 GPP) ^rd Generation Partnership Project) defines a method of guaranteeing data integrity and consistency due to various network element reboots. For example, when a PGW (PDN GateWay) fails or restarts, such as a mobility Management entity mme (mobility Management entity) detects a PGW failure or receives a PGW restart indication message,

the MME is required to scan all associated contexts, delete local contexts or trigger UE re-establishment.

This approach has the following drawbacks: (1) before a certain UE scans, data on the MME related to the UE is actually inaccurate, and when the UE or the network side triggers a service flow, a failure of the service flow may be caused; (2) this approach requires the MME to scan the context of all users, which can affect the normal traffic flow processing of the MME.

Disclosure of Invention

In view of the above-mentioned drawbacks, the present disclosure provides a communication method, NF, NRF, and computer-readable storage medium.

The present disclosure provides a communication method, including:

registering a mutual backup relationship between the NF and one or more NF in the NRF;

and when a context updating request sent by the first NF is received, acquiring UE context information which is stored in advance by a fault NF in the backup relation from a specified memory, and carrying out traffic migration.

The present disclosure also provides a communication method, including:

registering the mutual backup relationship between the NF and one or more NF;

and when a fault NF exists, determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF, and notifying a first NF of a state change notification event.

The present disclosure also provides a communication method, including:

changing the state of the fault NF according to the received state change notification event, and recording the standby NF of the fault NF;

sending a context update request to the standby NF.

The present disclosure provides a NF comprising a first registration module, and a context acquisition module;

the first registration module is used for registering the mutual backup relationship between the NF and one or more NFs to the NRF;

and the context acquisition module is used for acquiring UE context information which is stored in advance by a fault NF in the backup relation from a specified memory when receiving a context updating request sent by the first NF, and carrying out traffic migration.

The present disclosure further provides an NRF, including a second registration module and a selection module:

the second registration module is used for registering the mutual backup relationship between the NF and one or more NF;

and the selection module is used for determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF when the fault NF exists, and notifying a state change notification event to the first NF.

The present disclosure also provides a first NF, comprising a state change module and an update request sending module;

the state change module is used for changing the state of the fault NF and recording the standby NF of the fault NF according to the received state change notification event;

and the updating request sending module is used for sending a context updating request to the standby NF.

The present disclosure provides a computer-readable storage medium having stored thereon a communication control program which, when executed by a processor, implements the steps of any one of the communication methods described above.

According to the communication method, the NF, the NRF and the computer readable storage medium provided by the embodiment of the disclosure, full text scanning of the context is not required, when a session modification request is received, the first NF carries out the session request through the standby NF of the failed NF, the UE context information is recovered, the traffic migration is carried out, and meanwhile, the service flow can be continuously carried out to meet the requirements of the user service.

Drawings

Fig. 1 is a flow chart illustrating a communication method according to an embodiment of the disclosure;

fig. 2 is a flow chart illustrating a communication method according to another embodiment of the present disclosure;

fig. 3 is a flow chart illustrating a communication method according to another embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a NF according to the present disclosure;

FIG. 5 is a schematic diagram of a NRF according to the present disclosure;

FIG. 6 is a schematic diagram illustrating a first NF according to the present disclosure;

fig. 7 is an architecture diagram of a traffic migration system within the 5G system of the present disclosure;

fig. 8 is a traffic migration flow diagram triggered by UE activity when SMF fails in example 1 of the present disclosure;

fig. 9 is a schematic traffic migration flow diagram triggered by AF at SMF failure in example 2 of the present disclosure;

fig. 10 is a traffic restoration flow diagram triggered by UE activity at SMF restoration in example 3 of the present disclosure.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

In order to overcome the defects caused by the requirement that an MME scans all associated contexts when a PGW fails in the prior art, the present disclosure provides a communication method, NF, NRF, and computer-readable storage medium, which are described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the disclosure and do not limit the disclosure.

According to a first method embodiment of the present disclosure, a communication method is provided, which is applied to an NF of a service providing side, fig. 1 is a flowchart illustrating the communication method according to an embodiment of the present disclosure, and as shown in fig. 1, the communication method according to an embodiment of the present disclosure includes the following steps:

s101: the NF is registered with the NRF in a backup relationship with one or more NFs. That is, when the NF service is started, the backup relationship is registered on the NRF during the dynamic registration with the NRF.

Optionally, when the backup relationship includes a standby NF, the backup relationship includes: marking the standby NF; when the backup relationship includes a plurality of standby NFs, the backup relationship includes: an identification of each standby NF, and a corresponding priority. That is, if the NF is the master NF, only the identifier (for example, name) of the NF and the identifier of the master NF may be registered; if there are multiple standby NFs, the priorities of the different standby NFs may be registered separately, in addition to the identities.

S102: and when a context updating request sent by the first NF is received, UE context information stored in advance by a fault NF in the backup relation is acquired from a designated memory, and the telephone traffic is migrated.

That is, before the step S102, the failed NF (does not fail during the normal session) stores the UE context information to the memory during the normal session.

Optionally, the memory comprises: an unstructured data storage function entity, UDSF.

By adopting the communication method of the first method embodiment of the present disclosure, when a certain NF of the service providing side fails, the UE context information previously stored by the failed NF can be acquired in the specified memory according to the trigger of the first NF (i.e. the NF of the service requesting side), and the traffic migration is performed.

Optionally, in order to restart the NF on the service providing side, the call method according to the first embodiment of the present disclosure further includes the following steps: when the NF is restarted, the mutual backup relationship between the NF and one or more NF is registered with the NRF again, and the traffic is recovered by acquiring the UE context information previously stored by the NF from the memory.

Corresponding to the first method embodiment of the present disclosure, a second method embodiment is provided, which is applied to NRF, and fig. 2 is a schematic flow chart of a communication method according to another embodiment of the present disclosure, as shown in fig. 2, the communication method according to another embodiment of the present disclosure includes the following steps:

s201: registering the NF in a backup relationship with one or more NFs.

S202: and when the fault NF exists, determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF, and notifying the first NF of a state change notification event.

That is, the NRF may notify the backup NF information of the other NF's failing NF; on one hand, when the NF is found, the NRF can inform the NF on the service request side of the information of the standby NF, and on the other hand, the information can be acquired by the NRF when other NF needs to interact with the fault NF.

Optionally, the fault detection of NFs may be performed by mutual detection between NFs, or may be performed by a third-party detection method, such as NRF detection. When third party detection is adopted, the defect that the failure or restart of the PGW depends on the detection between the MME and the PGM in the prior art can be overcome.

Optionally, in order to ensure that the same standby NF is selected, on one hand, the same standby NF may be registered according to a certain priority order during NF registration, or may be ensured to be selected by an NRF through a configuration manner or a consistent hash manner. When the backup relationship of the registration of the fault NF comprises a plurality of standby NFs, determining the standby NF for taking over the service of the fault NF, comprising the following steps: according to the priority sequence of each standby NF in the backup relation registered by the fault NF, taking the standby NF with the highest priority as the determined standby NF for taking over the fault NF service; or, a preset selection policy (for example, a hash algorithm) is used to select a standby NF for taking over the service of the failed NF from the backup relationship registered by the failed NF.

In the second method embodiment of the present invention, after determining a standby NF for taking over a failed NF service, the method further includes: the determined standby NF is notified of the takeover event. I.e. it is triggered directly with a traffic takeover instruction to take over the traffic of the failed NF.

By adopting the communication method of the second method embodiment of the present disclosure, the backup information registered by a certain NF on the service providing side can be obtained in advance and stored, and when the NF fails, the standby NF is determined according to the stored backup information.

Corresponding to the first method embodiment and the second method embodiment of the present disclosure, a third method embodiment is provided, and is applied to a first NF (i.e., the NF on the service request side), fig. 3 is a flowchart illustrating a communication method according to another embodiment of the present disclosure, and as shown in fig. 3, the communication method according to another embodiment of the present disclosure includes the following steps:

s301: changing the state of the fault NF and recording the standby NF of the fault NF according to the received state change notification event;

s302: a context update request is sent to the standby NF.

Specifically, the standby NF should be able to receive the session flow, recover the state data of the user from the memory (e.g., UDSF), perform traffic migration, and ensure the service continuity of the user. Alternatively, traffic migration may be triggered by UE activity or the network side.

By adopting the communication method of the third method embodiment of the present disclosure, the standby NF for taking over the faulty NF service can be determined, the NF for providing the service on the service providing side stored in the first NF can be changed, and a context update request is sent to the standby NF according to the UE activity or the trigger of the network side.

By combining the first method embodiment, the second method embodiment and the third embodiment of the present disclosure, the communication method provided by the embodiment of the present disclosure has the following beneficial effects:

on one hand, when the NF fails, full scanning of context is not required, when the UE is active or the network side triggers the service, the first NF (i.e. the NF located at the service request side) performs a session request through the backup NF of the failed NF at the service providing side, recovers the UE context information, and completes the traffic migration.

Secondly, the same standby NF of the faulty NF is ensured to be selected through the NRF, so that the normal operation of the service can be ensured when the subsequent UE activity or the network side triggers the service.

Thirdly, when the NF is restored, when the UE is active or the network side triggers the service, the first NF (i.e. the NF located on the service request side) selects the standby NF to restore the context data, and at the same time, the service flow can be continued on the NF to meet the requirement of the user service.

Corresponding to the first method embodiment, the present disclosure provides a first apparatus embodiment, where the first apparatus embodiment of the present disclosure provides an NF applied to a service providing side, fig. 4 is a schematic structural diagram of the NF of the present disclosure, and as shown in fig. 4, the NF of the present disclosure includes: the first registration module 40 and the context obtaining module 42, the functions of which are described in detail below.

The first registration module 40 is configured to register, with the NRF, the NF and one or more NFs in a mutual backup relationship.

The context obtaining module 42 is configured to, when receiving a context update request sent by the first NF, obtain, from the specified storage, UE context information that is previously stored by a failed NF in the backup relationship, and perform traffic migration.

Optionally, the first registration module 40 is further configured to register, when the NF is restarted, a mutual backup relationship between the NF and one or more NFs with the NRF again; the context acquiring module 42 is further configured to perform traffic restoration by acquiring, from the memory, UE context information previously stored by the NF.

Corresponding to the second method embodiment, the present disclosure provides a second apparatus embodiment, the second apparatus embodiment of the present disclosure provides an NRF, fig. 5 is a schematic structural diagram of an NRF of the present disclosure, and as shown in fig. 5, an NRF of the present disclosure includes: the second registration module 50 and the selection module 52 will be described in detail below.

The second registration module 50 is configured to register a mutual backup relationship between the NF and one or more NFs.

And the selecting module 52 is configured to, when there is a faulty NF, determine a standby NF for taking over the faulty NF service according to the backup relationship registered by the faulty NF, and notify the first NF of a take-over event.

Optionally, the selecting module 52 is further configured to, after determining a standby NF for taking over the failed NF service, notify the determined standby NF of a take-over event.

The selecting module 52 is specifically configured to: according to the priority sequence of each standby NF in the backup relation registered by the fault NF, taking the standby NF with the highest priority as the determined standby NF for taking over the fault NF service; or, selecting the standby NF for taking over the service of the fault NF from the backup relation registered by the fault NF by using a preset selection strategy.

Corresponding to the third method embodiment, the present disclosure provides a third apparatus embodiment, where the third apparatus embodiment of the present disclosure provides a first NF (i.e., an NF located at a service request side), and fig. 6 is a schematic structural diagram of the first NF of the present disclosure, and as shown in fig. 6, the first NF of the present disclosure includes: the state change module 60 and the update request transmission module 62 will be described in detail below with respect to their functions.

A state change module 60, configured to change the state of the failed NF and record a standby NF of the failed NF according to the received state change notification event;

an update request sending module 62, configured to send a context update request to the standby NF.

The NF provided by the first device in the present disclosure, the NRF provided by the second device, and the first NF provided by the third device form a traffic migration system in the 5G system, and fig. 7 is an architecture diagram of the traffic migration system in the 5G system in the present disclosure. In fig. 7, the service requester NF corresponds to the first NF provided by the third device; service provider NF1 and service provider NF2 are NFs provided by the first apparatus embodiment, where service provider NF1 is a failed NF and service provider NF2 is a standby NF.

Based on the traffic migration system in the 5G system, the present disclosure provides a traffic migration method, which specifically includes example 1 to example 3.

Example 1: traffic migration flow triggered by UE activity when Session Management Function (SMF) fails

Fig. 8 is a traffic migration flow diagram triggered by UE activity when SMF fails in example 1 of the present disclosure, and as shown in fig. 8, the method includes the following steps:

s801, the SMF1 and the SMF2 are NF mutually backup, mutual backup relation between NRF is automatically registered when the NF is powered on, and the NRF records the mutual backup relation;

s802, UE triggers a registration and grouping Data unit PDU (packet Data Unit) establishing process, wherein an access and Mobility Management function AMF (Access and Mobility Management function) in the PDU establishing process queries an SMF from an NRF; NRF returns all relevant SMF to NRF and returns the mutual backup relation of SMFs according to configuration, AMF stores the information of two SMFs simultaneously and selects SMF1 to carry out PDU creation flow according to a certain rule such as SMF load condition; after the PDU is successfully established, the SMF stores the context steady-state data to the UDSF;

s803, when the SMF1 fails, the NRF detects and senses the SMF1 failure, finds that the SMF1 has backup NF (single face filter) of the SMF2 through the registered information, and directly triggers a service takeover instruction to the SMF 2; while the NRF informs all relevant NFs of including the AMF described above;

s804, the SMF2 receives the service takeover instruction of the NRF to start to take over the service of the SMF 1;

s805, the AMF updates the SMF of the local cache to be changed into SMF2 after receiving the change notice of the NRF; the SMF2 may obtain user data from the UDSF at this time or may obtain user data from the UDSF again when subsequent UEs are active;

s806, UE actively triggers PDU modification request to AMF, AMF initiates SMF context update request to SMF2 according to SMF2 of local cache;

s807, SMF2 has no context information of UE locally, initiates context acquisition to UDSF, UDSF returns the context information of the user to SMF2, thereby completing the migration of user traffic;

s808, after the SMF2 finishes the context updating operation, an SMF context updating response is returned to the AMF;

s809, the AMF returns a PDU modification response to the UE.

In the traffic migration method provided in example 1 of the present disclosure, when an NF on a service providing side fails, a NRF can ensure that a backup NF of the failed NF is selected to ensure continuity of a service when the upstream NF (UE activity) is triggered.

Example 2: AF-triggered traffic migration flow during SMF failure

Fig. 9 is a schematic view of a traffic migration flow triggered by an AF when an SMF fails in example 2 of the present disclosure, as shown in fig. 9, including the following steps:

s901, SMF1, SMF2 and SMF3 are NF which are mutually backup, and the backup relation is automatically registered to NRF when the system is powered on; if SMF1 registers with its own standby NF as SMF2 and SMF3, the priority may be 1 and 2, i.e., SMF2 is preferred and SMF3 is second preferred;

s902, UE triggers register and packet data unit PDU establishing process, wherein SMF1 is used in PDU establishing process to establish PDU and initiate strategy conversation establishing request to strategy Control function PCF (policy Control function), PCF records SMF1 information and subscribes SMF1 state to NRF; after the session is established, the SMF1 stores the context steady-state data in the UDSF;

s903, when SMF1 fails, the NRF detects the SMF1 failure and informs all related NF (networks) including the PCF; meanwhile, the NRF selects SMF2 as an alternative NF to inform all the NF according to the priority of the backup NF of the SMF 1;

s904, PCF receives the change notice of NRF to update the state information of SMF1 of local cache; an alternative NF to SMF1 was also recorded as SMF 2;

s905, an application function AF (application function) activity triggers a policy session modification request to a PCF (local area network) through a network capability open function NEF (network Exposure function), and the PCF initiates a context update request to an SMF2 according to the state of the SMF1 cached locally and corresponding backup NF information;

s906, SMF2 has no context information of UE locally, and initiates context acquisition to UDSF, UDSF returns context information of user to SMF2, thereby completing migration of user traffic;

s907, SMF2 returns context update response to PCF after completing context update operation;

s908, the PCF returns a policy session modification response to the AF.

In the traffic migration method provided in example 2 of the present disclosure, when an NF of a service providing side fails, a back-up NF of the failed NF is selected to ensure continuity of a service when a downstream NF (network side) is triggered by an NRF.

Example 3: traffic recovery flow triggered by UE activity during SMF recovery

Fig. 10 is a traffic recovery flow diagram triggered by UE activity when SMF is recovered in example 3 of the present disclosure, and as shown in fig. 10, the method includes the following steps:

s1001, the SMF1 and the SMF2 are NF which are mutually backed up, and the backup relation is automatically registered to the NRF when the system is powered on;

s1002, UE triggers registration and PDU establishment processes, wherein in the PDU establishment process, AMF inquires SMF from NRF to obtain SMF1 and SMF2, and simultaneously stores information of the two SMFs and selects SMF1 to perform the PDU establishment process; after the PDU is successfully established, the SMF stores the context steady-state data to the UDSF;

s1003, the SMF1 is restarted, the NRF detects that the SMF1 is broken, and all related NF, including the AMF, is informed;

s1004, the AMF updates the state information of the SMF1 of the local cache after receiving the change notice of the NRF;

s1005, after a period of time, the SMF1 restarts the power-on and finishes the power-on to continuously initiate registration to the NRF, the NRF updates the state of the SMF1 and informs all NF subscribing the SMF1, including the AMF;

s1006, UE actively triggers PDU modification request to AMF, AMF directly initiates SMF session modification request to SMF1 according to SMF1 cached locally because SMF1 state has been restored;

s1007, SMF1 initiates context acquisition to UDSF because SMF1 is restarted and has no context information of UE locally, UDSF returns context information of user to SMF1 to complete migration of user traffic;

s1008, SMF1 returns SMF context update response to AMF after completing context update operation;

s1009, the AMF returns a PDU modification response to the UE.

The traffic migration method provided in example 3 of the present disclosure can perform traffic restoration by using a backup NF when the NF on the service providing side is restarted.

The present disclosure provides a computer-readable storage medium applied to a service providing side, the computer-readable storage medium having a communication control program stored thereon, the communication control program implementing the following steps when executed by a processor:

step 11: registering a mutual backup relationship between a network function entity NF and one or more NF with a network function repository NRF.

Optionally, when the backup relationship includes a standby NF, the backup relationship includes: an identification of the standby NF; when the backup relationship comprises a plurality of standby NFs, the backup relationship comprises: an identification of each standby NF, and a corresponding priority.

Step 12: and when a context updating request sent by the first NF is received, acquiring UE context information which is stored in advance by a fault NF in the backup relation from a specified memory, and carrying out traffic migration.

Optionally, in order to restart the service providing side NF, the communication control program, when executed by the processor, implements the following steps: when the NF is restarted, registering the mutual backup relationship between the NF and one or more NF to the NRF again, and recovering the telephone traffic by acquiring the UE context information previously stored by the NF from the memory.

The present disclosure still further provides a second computer-readable storage medium having a communication control program stored thereon, the communication control program, when executed by a processor, implementing the steps of:

step 21: registering the mutual backup relationship between the network function entity NF and one or more NF.

Step 22: when a fault NF exists, determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF, and notifying a state change notification event to a first NF.

Optionally, in a second computer-readable storage medium, the communication control program when executed by the processor implements the following steps: after determining a standby NF for taking over the failed NF traffic, notifying the determined standby NF of a take-over event.

Optionally, when the backup relationship registered by the failed NF includes a plurality of standby NFs, the determining the standby NF for taking over the service of the failed NF includes: according to the priority sequence of each standby NF in the backup relation registered by the fault NF, taking the standby NF with the highest priority as the determined standby NF for taking over the fault NF service; or, a preset selection strategy is used for selecting the standby NF for taking over the fault NF service from the backup relation registered by the fault NF.

The present disclosure also provides a third computer-readable storage medium having a communication control program stored thereon, the communication control program, when executed by a processor, implementing the steps of:

step 31: and changing the state of the fault NF according to the received state change notification event, and recording the standby NF of the fault NF.

Step 32: sending a context update request to the standby NF.

The embodiment of the disclosure provides a computer-readable storage medium, which does not need to perform full-text scanning of a context, and when a session modification request is received, a first NF performs a session request through a standby NF of a failed NF, recovers context information of a UE, performs traffic migration, and can continue to perform a service flow to meet the requirements of a user service.

The above description is only an example of the present disclosure and is not intended to limit the present disclosure, and various modifications and changes may be made to the present disclosure by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure should be included in the scope of the claims of the present disclosure.

Claims

1. A communication method applied to a network function entity NF on a service providing side, comprising:

registering a mutual backup relationship between a network function entity NF and one or more NF to a network function repository NRF;

when a context updating request sent by a first NF is received, UE context information stored in advance by a fault NF in the backup relation is acquired from a designated memory, and telephone traffic migration is carried out; the first NF is a NF at the service request side, and the memory comprises an unstructured data storage function entity UDSF.

2. The communication method of claim 1,

when the backup relationship comprises a standby NF, the backup relationship comprises: an identification of the standby NF;

when the backup relationship comprises a plurality of standby NFs, the backup relationship comprises: an identification of each standby NF, and a corresponding priority.

3. The communication method according to claim 1 or 2, wherein the method further comprises:

when the NF is restarted, registering the mutual backup relationship between the NF and one or more NF to the NRF again, and recovering the telephone traffic by acquiring the UE context information previously stored by the NF from the memory.

4. A method of communication, comprising:

registering the mutual backup relationship between a network function entity NF and one or more NF;

when a fault NF exists, determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF, and notifying a state change notification event to a first NF, so that the first NF sends a context updating request to the standby NF according to the change notification event; wherein, the context update request is used to instruct the standby NF to acquire the UE context information previously stored by the failed NF from a specified storage, and perform traffic migration.

5. The communication method of claim 4, wherein after determining a standby NF to take over the failed NF traffic, further comprising:

the determined standby NF is notified of the takeover event.

6. The communication method according to claim 4 or 5, wherein when a plurality of standby NFs are included in the backup relationship of the faulty NF registration, the determining a standby NF for taking over the faulty NF traffic includes:

according to the priority sequence of each standby NF in the backup relation registered by the fault NF, taking the standby NF with the highest priority as the determined standby NF for taking over the fault NF service;

or, selecting a standby NF for taking over the fault NF service in the backup relation registered by the fault NF by using a preset selection strategy.

7. A communication method is applied to NF on a server request side, and is characterized by comprising the following steps:

and sending a context updating request to the standby NF so that the standby NF can acquire the UE context information which is stored in advance by the failure NF from a specified memory to perform traffic migration.

8. A network function entity NF is characterized by comprising a first registration module and a context acquisition module;

the context obtaining module is used for obtaining UE context information which is stored in advance by a fault NF in the backup relation from a specified memory when receiving a context updating request sent by a first NF, and carrying out telephone traffic migration; the first NF is an NF at the service request side, and the memory comprises an unstructured data storage function entity UDSF.

9. The NF of claim 8,

the first registration module is further configured to register, to the NRF, a mutual backup relationship between the NF and one or more NFs when the NF is restarted;

the context obtaining module is further configured to obtain, from the memory, the UE context information previously stored by the NF, and perform traffic restoration.

10. A network function repository (NRF) is characterized by comprising a second registration module and a selection module:

the second registration module is used for registering the mutual backup relationship between the network function entity NF and one or more NF;

the selection module is used for determining a standby NF for taking over the fault NF service according to the backup relation registered by the fault NF when the fault NF exists, and notifying a state change notification event to a first NF, so that the first NF sends a context updating request to the standby NF according to the change notification event; wherein, the context update request is used to instruct the standby NF to acquire the UE context information previously stored by the failed NF from a specified storage, and perform traffic migration.

11. The NRF of claim 10, wherein:

the selecting module is further configured to notify the determined standby NF of a takeover event after determining the standby NF for taking over the failed NF service.

12. The NRF of claim 10 or 11, wherein said selection module is specifically configured to:

or, a preset selection strategy is used for selecting the standby NF for taking over the fault NF service from the backup relation registered by the fault NF.

13. A first network function entity NF is characterized by comprising a state change module and an update request sending module;

and the update request sending module is used for sending a context update request to the standby NF so that the standby NF can acquire the UE context information which is previously stored by the failure NF from a specified memory to perform traffic migration.

14. A computer-readable storage medium, characterized in that a communication control program is stored thereon, which when executed by a processor implements the steps of the communication method according to any one of claims 1 to 3 or any one of claims 4 to 6 or claim 7.