CN110324911B

CN110324911B - PCF addressing method, device and system

Info

Publication number: CN110324911B
Application number: CN201810297704.8A
Authority: CN
Inventors: 黄震宁; 陈旭; 蔡慧; 孙滔
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2018-03-30
Filing date: 2018-03-30
Publication date: 2021-05-11
Anticipated expiration: 2038-03-30
Also published as: CN110324911A

Abstract

The invention discloses a method, equipment and a system for PCF addressing, which are used for solving the problem that the binding information cannot be searched for from a designated GW through the addressing of planning information when a gateway local unaddressed pool exists in the prior art. In the embodiment of the invention, one or more corresponding second network elements are determined through the first IP information of the terminal, the second network elements inquire the user context according to the second IP address of the terminal, and return the bound PCF address if the user context is inquired, and then the first network elements send the information for realizing the user session binding to the PCF according to the returned PCF address to realize the session binding.

Description

PCF addressing method, device and system

Technical Field

The present invention relates to the field of wireless communication technologies, and in particular, to a method, a device, and a system for PCF (Policy Control Function) addressing.

Background

In order to achieve the objectives of differentiated Service capability, resource grooming capability, network traffic optimization capability, etc., according to the 3rd Generation Partnership Project (3 GPP) standard specification, a Policy and Charging Control (PCC) system architecture is introduced into the existing packet network to perform QoS (Quality of Service) Control on packet data services.

The main network elements of the PCC architecture include PCRF (Policy and Charging Rules Function), PCEF (Policy and Charging implementation Function), AF (Application Function), OCS/OFCS (Online Charging System/Offline Charging System), and SPR (Subscription Profile Repository).

In the existing method, the session binding relations of all users in the network are stored separately in a new functional entity or a data storage functional entity, or directly inquired on a session related NF with user session binding information, so that extra separate storage and dynamic maintenance of the session binding information are avoided. However, the existing method is only applicable to a scheme of locally allocating an IP (Internet Protocol) to a gateway, and if the gateway does not have an address pool locally, the gateway cannot be addressed to a specified gateway through the planning information to search for the binding information.

In summary, at present, if the local unaddressed pool of the gateway cannot be addressed to the designated gateway through the planning information to search the binding information.

Disclosure of Invention

The invention provides a method, equipment and a system for PCF addressing, which are used for solving the problem that the binding information cannot be searched for from a specified gateway through the addressing of planning information in the prior art when a gateway local unaddressed pool exists.

The embodiment of the invention provides a PCF addressing method, which comprises the following steps:

the first network element determines one or more second network elements corresponding to the first IP information according to the received first IP information of the terminal;

the first network element sends a second IP address of the terminal to the one or more second network elements;

and the first network element sends the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element.

Optionally, the first Network element is an NEF (Network Exposure Function, Network open Function) or an NRF (NF registration Function, Network element registration Function) or an AF; and/or

The second network element is a SMF (Session Management Function) or a SMF front-end processor, BSF (Binding Support Function).

Optionally, the first IP information includes part or all of the following:

the public Network IP Address, the public Network IP Address mask code, the name of NAT (Network Address Translation) corresponding to the public Network IP Address, the information representing the name of the public Network IP domain and the information representing the NF (Network element) where the user is located.

Optionally, the determining, by the first network element, one or more second network elements corresponding to the first IP information according to the received first IP information of the terminal includes:

the first network element determines the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determines the second network element corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the second network element; or

And the first network element determines a second network element corresponding to the received first IP information according to the corresponding relation between the first IP information and the second network element.

Optionally, the second network element is an SMF front-end processor;

the method for determining one or more second network elements corresponding to the first IP information by the first network element according to the received first IP information of the terminal comprises the following steps:

the first network element determines the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determines the SMF corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the SMF; or determining the SMF corresponding to the received first IP information according to the corresponding relation between the first IP information and the SMF;

and the first network element determines the SMF front-end processor corresponding to the SMF determined according to the first IP information according to the corresponding relation between the SMF and the SMF front-end processor.

Optionally, the second network element is an SMF, and there are multiple second network elements;

the first network element sending the second IP address of the terminal to the one or more second network elements, further comprising:

the first network element sends the second IP addresses of the terminals to a plurality of second network elements in a polling mode, and stops sending the second IP addresses if the PCF addresses returned by the second network elements are received; or

And the first network element simultaneously and respectively sends the second IP addresses of the terminals to a plurality of second network elements.

the second network element receives a second IP address of the terminal sent by the first network element according to the first IP information of the terminal;

the second network element determines a PCF address bound with a user context corresponding to a second IP address of the terminal;

and the second network element sends the PCF address to the first network element.

Optionally, if the second network element cannot determine the PCF address bound to the user context corresponding to the second IP address of the terminal, a query failure message is returned to the first network element.

Optionally, the first network element is a network open function NEF, NRF, or AF; and/or

And the second network element is an SMF or an SMF front-end processor or a BSF.

Optionally, the first IP information includes part or all of the following:

the method comprises the steps of obtaining a public network IP address, a public network IP address mask, a name of NAT corresponding to the public network IP address, information representing the name of a public network IP domain and NF information representing the user.

Optionally, the second network element is an SMF front-end processor;

the determining, by the second network element, the PCF address bound to the user context corresponding to the second IP address of the terminal includes:

the second network element sends the received second IP address to one or more SMFs connected with the second network element;

and the second network element receives the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address.

Optionally, there are a plurality of SMFs connected to the second network element;

the second network element sends the received second IP address to one or more SMFs connected to the second network element, further comprising:

the second network element sends the second IP address of the terminal to the SMFs in a polling mode, and stops sending the second IP address if receiving the PCF address returned by the SMFs; or

And the second network element simultaneously and respectively sends the second IP addresses of the terminals to the SMFs.

The embodiment of the invention provides a first network element addressed by a PCF, which comprises: a processor and a transceiver:

the processor is configured to perform data transmission through the transceiver, and determine one or more second network elements corresponding to first IP information according to the received first IP information of the terminal; sending a second IP address of the terminal to the one or more second network elements; and sending the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element.

Optionally, the first IP information includes part or all of the following:

Optionally, the processor is specifically configured to:

determining the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determining the second network element corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the second network element; or

And determining a second network element corresponding to the received first IP information according to the corresponding relation between the first IP information and the second network element.

Optionally, the second network element is an SMF front-end processor; the processor is specifically configured to:

determining the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determining the SMF corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the SMF; or determining the SMF corresponding to the received first IP information according to the corresponding relation between the first IP information and the SMF;

and determining the SMF front-end processor corresponding to the SMF determined according to the first IP information according to the corresponding relation between the SMF and the SMF front-end processor.

Optionally, the second network element is an SMF, and there are multiple second network elements; the processor is specifically configured to:

sending a second IP address of the terminal to a plurality of second network elements in a polling mode, and stopping sending if receiving a PCF address returned by the second network elements; or

And simultaneously and respectively sending the second IP addresses of the terminals to a plurality of second network elements.

The embodiment of the invention provides a second network element addressed by a PCF, which comprises: a processor and a transceiver:

the processor is used for transmitting data through the transceiver and receiving a second IP address of the terminal, which is sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; and sending the PCF address to the first network element.

Optionally, the processor is specifically configured to:

and if the second network element can not determine the PCF address bound with the user context corresponding to the second IP address of the terminal, returning a query failure message to the first network element.

Optionally, the first IP information includes part or all of the following:

sending the received second IP address to one or more SMFs connected with the second network element; and receiving the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address.

Optionally, there are a plurality of SMFs connected to the second network element; the processor is further configured to:

sending a second IP address of the terminal to the SMFs in a polling mode, and stopping sending if receiving PCF addresses returned by the SMFs; or

And simultaneously and respectively sending the second IP addresses of the terminals to the SMFs.

The embodiment of the invention provides a first network element addressed by a PCF, which comprises:

at least one processing unit and at least one memory unit, wherein the memory unit stores program code that, when executed by the processing unit, causes the processing unit to perform the following:

determining one or more second network elements corresponding to first IP information according to the received first IP information of the terminal; sending a second IP address of the terminal to the one or more second network elements; and sending the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element.

Optionally, the first IP information includes part or all of the following:

Optionally, the processing unit is specifically configured to:

Optionally, the second network element is an SMF front-end processor; the processing unit is specifically configured to:

Optionally, the second network element is an SMF, and there are multiple second network elements; the processing unit is specifically configured to:

The embodiment of the invention provides a second network element addressed by a PCF, which comprises:

receiving a second IP address of the terminal sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; and sending the PCF address to the first network element.

Optionally, the processing unit is specifically configured to:

Optionally, the first IP information includes part or all of the following:

Optionally, there are a plurality of SMFs connected to the second network element; the processing unit is further to:

An embodiment of the present invention provides a computer-readable medium, on which a computer program is stored, wherein the computer program is configured to implement the steps of the method when executed by a processor.

In the embodiment of the invention, a first network element determines one or more second network elements corresponding to first IP information according to the received first IP information of a terminal; then sending a second IP address of the terminal to the one or more second network elements; the second network element receives a second IP address of the terminal sent by the first network element according to the first IP information of the terminal, determines a PCF address bound with the user context corresponding to the second IP address of the terminal, and then sends the PCF address to the first network element; and the first network element sends the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element. The embodiment of the invention determines one or more corresponding second network elements through the first IP information of the terminal, then the second network element inquires the corresponding user context according to the second IP address of the terminal sent by the first network element, and if the inquiry is successful, the bound PCF address is returned, and PCFs providing services for the terminal are sequentially determined. And the first network element sends the information for realizing the user session binding to the PCF according to the returned PCF address to realize the session binding, compared with the prior art that the gateway must determine the SMF serving the terminal in the specific planning information of the local address pool according to the second IP address of the terminal, the invention can find the unique second network element serving the terminal by inquiring the second network element after determining one or more second network elements corresponding to the terminal when the local address pool does not exist.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic diagram of manually planning a private network IP address pool of an SMF according to an embodiment of the present invention;

FIG. 2 is a diagram illustrating manual planning of a public network IP address pool of NAT according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a system architecture for PCF addressing according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a method for determining a second network element for a first SMF according to the embodiment of the present invention;

fig. 5 is a schematic diagram of a second method for determining a second network element for an SMF according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a first method for querying a user context, where a second network element is an SMF according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a second method for querying a user context, where a second network element is an SMF according to the embodiment of the present invention;

fig. 8 is a schematic diagram illustrating a method for determining a second network element for a first network element of an SMF front-end processor according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a second method for determining a second network element for an SMF front-end processor according to the embodiment of the present invention;

fig. 10 is a diagram illustrating a second network element corresponding to first IP information of a terminal determined by an SMF pre-engineer in accordance with the second embodiment of the present invention;

fig. 11 is a schematic diagram of a first method for querying a user context, where a second network element is an SMF front-end processor according to an embodiment of the present invention;

fig. 12 is a schematic diagram illustrating a second method for querying a user context, where the second network element is an SMF front-end processor according to the embodiment of the present invention;

fig. 13 is a flowchart illustrating a method for a second network element to address a PCF of an SMF according to an embodiment of the present invention;

fig. 14 is a flowchart illustrating a method for a second network element to address a PCF of an SMF front-end processor according to an embodiment of the present invention;

fig. 15 is a flowchart illustrating a first PCF addressing method according to an embodiment of the present invention;

fig. 16 is a flowchart illustrating a first PCF addressing method according to an embodiment of the present invention;

fig. 17 is a schematic structural diagram of a first network element addressed by a first PCF according to an embodiment of the present invention;

fig. 18 is a schematic structural diagram of a first network element addressed by a first PCF according to an embodiment of the present invention;

fig. 19 is a schematic structural diagram of a second network element addressed by a second PCF according to an embodiment of the present invention;

fig. 20 is a schematic structural diagram of a second network element addressed by a second PCF according to an embodiment of the present invention.

Detailed Description

In a 5G (5th-Generation, fifth-Generation mobile communication technology) network, IP addresses in a group of SMFs do not repeat, the group of SMFs has a public IP address, after a User Session is established, an SMF has a correspondence between a User ID (Identity) and an IP address, and in a PDU Session Establishment (Protocol data unit Session), the SMF can obtain Session binding information of an a-center PDU Session, which is stored in a UE (User Equipment, User terminal), so that the SMF can query a User context according to the private network IP address of the User to determine an SMF serving as a terminal.

When IP address is allocated, in the same NAT, IP address pools divided for a group of SMFs are planned in advance and are not overlapped, so that the unique SMF for providing session management for a user can be found under the current NAT through an IP address segment to which the user private network IP address belongs.

And among different NATs, the allocated public network IP addresses are also planned in advance and do not overlap, so that the NAT providing session management for the user can be found through the IP address segment to which the user public network IP address belongs, and a group of SMFs existing under the NAT can be found.

The unique SMF serving the subscriber can be determined by combining the subscriber's public and private network IP addresses.

After finding the SMF, addressing to the PCF may be achieved by directly querying the session binding information on the SMF.

In specific implementation, a private network IP address pool of the SMF and a public network IP address pool of the NAT are planned first.

As shown in fig. 1, in planning the private network IP address pool of the SMF, a correspondence table of all SMFs and private network IP address segments is preset on the NEF, the NRF, or the BSM, so that a group of SMFs and private network IP address segments under the same NAT are in one-to-one correspondence, and there is no overlapping area between the private network IP address segments corresponding to each SMF. In the figure, SMF1 and SMF2 share private network address segments 192.168.1.0-192.168.4.9, the SMFs are planned in sequence only to the last SMF, and SMFn corresponds to the private network address segments 192.168.9.0-192.168.9.9, so that one-to-one correspondence between the SMFs and the private network address segments is formed.

As shown in fig. 2, when planning the public network IP address pool of the NAT, a correspondence table between the NAT and the public network IP address segment and a correspondence table between the NAT and all SMFs under the NAT may be preset on NEF, NRF, or BSF, so that the correspondence between the public network IP address segment and all SMFs may be determined through the correspondence between the NAT and the public network IP address segment and the correspondence between the NAT and all SMFs under the NAT. In the figure, the public network address segments 1.2.0.1-1.2.3.9 correspond to NAT1, and the NAT1 corresponds to SMF1 and SMF2, so that the corresponding relation between the public network address segments 1.2.0.1-1.2.3.9 and NAT1 and the corresponding SMF is formed. In addition, after the corresponding relation between the public network address segments 1.2.0.1-1.2.3.9 and the NAT1 and the corresponding SMF is formed, the NAT can be removed, and the corresponding relation between the public network address segments and the SMF can be directly formed.

In addition, the corresponding relation table of the public network IP address field and the SMF can be directly preset on the NEF, the NRF or the BSF, so that the conversion process can be reduced compared with the method, and the PCF addressing process is simpler and more convenient.

In addition, when the second network element is the corresponding relationship between the SMF front-end processor and the SMF, it also needs to be planned manually in advance.

The steps of planning the private network IP address pool of the SMF and the public network IP address pool of the NAT are both completed manually.

After the corresponding relation between the SMF and the private network IP address field is set and the corresponding relation between the public network IP address field, the NAT and the SMF is determined, PCF addressing can be completed by using the set corresponding relation, and further session binding is completed.

In order to make the objects, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail with reference to the accompanying drawings, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 3, the present invention provides a system for PCF addressing, the system comprising:

the first network element 300 is configured to receive first IP information of a terminal, where the first IP information corresponds to one or more second network elements; sending a second IP address of the terminal to the one or more second network elements; sending information for realizing user session binding to the PCF according to the PCF address returned by the second network element;

the second network element 301 receives a second IP address of the terminal sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; and sending the PCF address to the first network element.

In the embodiment of the invention, a first network element determines one or more second network elements corresponding to first IP information according to the received first IP information of a terminal; then sending a second IP address of the terminal to the one or more second network elements; the second network element receives a second IP address of the terminal sent by the first network element according to the first IP information of the terminal, determines a PCF address bound with the user context corresponding to the second IP address of the terminal, and then sends the PCF address to the first network element; and the first network element sends the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element.

Compared with the prior art, the embodiment of the invention determines one or more corresponding second network elements through the first IP information of the terminal, then the second network element inquires the corresponding user context according to the second IP address of the terminal sent by the first network element, and if the inquiry is successful, the bound PCF address is returned, and PCFs providing services for the terminal are sequentially determined. And the first network element sends the information for realizing the user session binding to the PCF according to the returned PCF address to realize the session binding, compared with the prior art that the gateway must determine the SMF serving the terminal in the specific planning information of the local address pool according to the second IP address of the terminal, the invention can find the unique second network element serving the terminal by inquiring the second network element after determining one or more second network elements corresponding to the terminal when the local address pool does not exist.

Optionally, the first network element includes, but is not limited to, NEF or NRF or AF.

Taking NEF as an example, the planned correspondence between the SMF and the second IP address segment and the correspondence between the first IP information segment, the NAT, and the second network element are all cached in the NEF, and in the subsequent process, a group of SMFs serving the terminal may be determined through the cached correspondence in the NEF. The first network element has the same function and the same operation steps in this scheme, so it is not described one by one, and only NEF is taken as an example for illustration.

Optionally, the first IP information includes, but is not limited to, the following parameters: the method comprises the steps of obtaining a public network IP address, a public network IP address mask, a name of NAT corresponding to the public network IP address, information representing the name of a public network IP domain and NF information representing the user.

Each parameter included in the first IP information corresponds to the equipment connection public network IP address, and the NAT to which the public network IP address of the terminal belongs can be determined according to the information. And further determining the SMF corresponding to the terminal.

Optionally, the second network element is an SMF, an SMF front-end processor, or a BSF.

The processing method is also different for different second network elements, and the following is introduced separately:

scenario one, the second network element is SMF.

First, when session binding is implemented, a first network element needs to determine one or more second network elements corresponding to first IP information according to the received first IP information of a terminal.

There are two ways for determining one or more second network elements corresponding to the first IP information in the embodiments of the present invention, which are described in detail below.

In the determination method 1, as shown in fig. 4, the first network element determines the second network element according to the correspondence preset on the first network element between the NAT and the first IP information segment and the correspondence preset on the first network element between the NAT and one or more SMFs corresponding to the NAT.

Optionally, the first network element determines, according to a correspondence between the NAT and the first IP information, the NAT corresponding to the received first IP information, and determines, according to a correspondence between the NAT and the second network element, the second network element corresponding to the NAT corresponding to the received first IP information.

In the specific implementation, the public network IP address pool of the NAT is manually planned before the addressing operation is performed, so as to determine the corresponding relationship between the first IP information, namely the NAT and the SMF.

In the embodiment of the invention, in the process of determining the second network element according to the corresponding relation of the preset NAT and the first IP information segment on the first network element and the corresponding relation of one or more SMFs corresponding to the NAT and the NAT, one or more SMFs can be determined by screening the first IP information, and the SMFs inquire the context of the user according to the private network address of the user so as to determine the only SMF for providing service for the terminal. Compared with the prior art, the method and the device for determining the SMF for providing the service for the terminal by inquiring the gateway local address pool have the advantages that the corresponding SMF can be accurately found even if the SMF does not have the local address pool, and therefore the scheme of the invention is wider in application range.

After planning the first IP information pool of the NAT as shown in fig. 4, the shown corresponding relationship between the first IP information segment, the NAT and the SMF is obtained, where the range of the public network IP address pool is 1.2.3.4-1.2.255.255, the NAT is divided into n NATs, the public network IP address in the interval of the public network IP address segment 1.2.0.1-1.2.3.9 is allocated to the NAT1, 2 SMFs are correspondingly allocated in the NAT1, and 2 SMFs are correspondingly allocated in the NAT2, so that a set of corresponding relationship between the public network IP address segment 1.2.0.1-1.2.3.9 and the NAT and SMF is formed. Wherein, each NAT corresponds to one or more SMFs.

Assuming that the terminal's public network IP address is 1.2.3.4, it can be determined that the terminal's public network IP address belongs within the public network IP address segment 1.2.3.4-1.2.3.9, corresponds to NAT1, and has two corresponding SMFs.

In the determining mode 2, as shown in fig. 5, the first network element determines the second network element according to the corresponding relationship between the first IP information segment and the SMF, which is directly preset on the first network element.

Optionally, the first network element determines, according to a correspondence between the first IP information and the second network element, the second network element corresponding to the received first IP information.

In specific implementation, besides determining a group of SMFs associated with the terminal according to the correspondence between the NAT and the first IP information and the correspondence between the NAT and the SMF, a corresponding group of SMFs may be determined directly according to the correspondence between the first IP information and the SMF on the first network element.

As shown in fig. 5, after planning the public network IP address pool of the NAT, the illustrated corresponding relationship between the public network IP address segment, the NAT and the SMF is obtained, wherein the range of the public network IP address pool is 1.2.3.4-1.2.255.255, the NAT is divided into n NATs, the public network IP address in the interval of the public network IP address segment 1.2.0.1-1.2.3.9 is allocated to the NAT1, and 2 SMFs are correspondingly arranged in the NAT1, so that a set of corresponding relationships between the public network IP address segment 1.2.0.1-1.2.3.9 and the NAT and the SMF is formed, and then the middle NAT is discarded, so that the corresponding relationship between the public network IP address segment 1.2.0.1-1.2.3.9 and the corresponding SMF1 and SMF2 is formed. Wherein, each public network IP address field corresponds to one or more SMFs.

If the public network IP address of the terminal is 1.2.3.4, it can be determined that the public network IP address of the terminal belongs to the public network IP address field 1.2.3.4-1.2.3.9 according to the public network IP address 1.2.3.4 of the terminal, and it is directly determined that the terminal corresponds to two SMFs.

Compared with the above scheme, in the scheme, after the corresponding relationship is established, the intermediate NAT bridge is omitted, and the corresponding relationship between the first IP information and the SMF is directly formed, so that only one step is needed to determine a group of required SMFs associated with the terminal. The searching steps are relatively reduced, the process is simplified, and the efficiency is improved.

After determining one or more SMFs corresponding to the first IP information, a specific unique SMF needs to be further determined according to the second IP address of the terminal.

Optionally, the first network element sends a second IP address of the terminal to the one or more second network elements;

correspondingly, the second network element receives the second IP address of the terminal sent by the first network element according to the first IP information of the terminal, and sends the PCF address to the first network element.

In the embodiment of the present invention, one or more SMFs corresponding to the first IP information of the terminal may be determined according to the above steps, and a unique SMF of the SMFs must provide a service for the terminal, because the SMFs in the SMFs under the same NAT do not share the second IP address, the unique SMF bound to the terminal may be determined according to the second IP address of the terminal.

After the first IP information of the terminal determines that the user is NAT1, the NEF sends a query request message carrying the second IP address of the terminal to the SMF, and the SMF receives the second IP address of the terminal and queries the user context according to the second IP address of the terminal. And when the SMF inquires the user context corresponding to the second IP address of the terminal, acquiring the address of the PCF bound with the user context, and sending the address of the PCF to the first network element. Thus, the NEF successfully finds out the address of the PCF providing the service for the terminal, and can directly address the PCF during the subsequent user session binding, thereby completing the session binding.

When the SMF queries the user context, there are many ways of querying the user context, and only two ways are described below.

Polling mode 1, SMF queries user context by polling mode.

Optionally, when the second network element is an SMF, there are a plurality of second network elements; the first network element sends the second IP addresses of the terminals to the second network elements in a polling mode, and stops sending the second IP addresses if the PCF addresses returned by the second network elements are received;

correspondingly, if the second network element cannot determine the PCF address bound to the user context corresponding to the second IP address of the terminal, a query failure message is returned to the first network element.

As shown in fig. 6, when SMF queries user context, NEF sends private network IP address query request message carrying terminal to SMF1, SMF2, SMF3 in sequence, SMF1 receives the query request message, searches user context according to the private network IP address of the terminal, if finds corresponding user context, SMF1 returns PCF address bound with user context and stops querying, otherwise, SMF1 returns query failure message; after SMF1 returns the query failure message, NEF sends the private network IP address query request message of the portable terminal to SMF2 again, SMF2 receives the query request message, searches the user context according to the private network IP address of the terminal, if the corresponding user context is found, SMF2 returns the address of PCF bound with the user context and stops querying, otherwise, SMF2 returns the query failure message; after SMF2 returns the failure message, NEF sends the inquiry request message of carrying the terminal private network IP address to SMF3, SMF3 receives the inquiry request message, and searches the user context according to the terminal private network IP address, and then searches the corresponding user context.

By using a polling query mode, the first network element can abandon the subsequent SMF query after receiving the exact PC address returned by the second network element, thereby reducing the resource loss.

And the polling mode 2 and the SMF adopt a mode of simultaneous transmission to inquire the user context.

Optionally, when the second network element is an SMF, there are a plurality of second network elements; and simultaneously and respectively sending the second IP addresses of the terminals to a plurality of second network elements.

As shown in fig. 7, when SMF queries the user context, NEF simultaneously sends a private network IP address query request message of the portable terminal to SMF1, SMF2, SMF 3.

The SMF1 receives the query request message, searches the user context according to the private network IP address of the terminal, if the corresponding user context is searched, the SMF1 returns the address of the PCF bound with the user context, otherwise, the SMF1 returns the query failure message;

the SMF2 receives the query request message, searches the user context according to the private network IP address of the terminal, if the corresponding user context is searched, the SMF2 returns the address of the PCF bound with the user context, otherwise, the SMF2 returns the query failure message;

the SMF3 receives the query request message, searches the user context according to the private network IP address of the terminal, if the corresponding user context is searched, the SMF3 returns the address of the PCF bound with the user context, otherwise, the SMF3 returns the query failure message;

in the figure, SMF2 finds out the corresponding user context and returns the address of the PCF bound with the user context, and SMF1 and SMF3 return inquiry failure messages.

Finally, optionally, the first network element sends the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element;

and the first network element sends a request to the PCF after obtaining the returned PCF address, and carries the SMF identification and the second IP address of the user. And the PCF executes binding according to the corresponding relation between the SMF identification and the second IP address of the user and provides service for the user, thereby completing the whole session binding process.

And the determined one or more corresponding second network elements determine the unique second network element serving the terminal through user context query, and return the address of the PCF. In the process, the determination of the only second network element serving the terminal does not depend on the planning information of the local address pool of the second network element, the determination can be performed only by inquiring the context information of the user and feeding back the inquiry result by the second network element, and the second network element does not need to have the local address pool of the second network element, so that the application range of the scheme is wider.

And in the second scenario, the second network element is an SMF front-end processor.

When the SMF front-end processor is used as a second network element, it functions as a bridge for information transmission between the first network element and the determined corresponding set of SMFs, the message sent to the SMF by the first network element can be sent to the SMF only through the SMF front-end processor, and the message sent to the first network element by the SMF also needs to be sent through the SMF front-end processor.

In the determination method 1, as shown in fig. 8, the first network element determines the second network element according to the correspondence preset on the first network element between the NAT and the first IP information segment and the correspondence preset on the first network element between the NAT and one or more SMFs corresponding to the NAT.

In the specific implementation, the public network IP address pool of the NAT is manually planned before the addressing operation is carried out, so that the corresponding relation between the public network IP address segments-NAT-SMF is determined.

In the embodiment of the invention, in the process of determining the second network element according to the corresponding relation of the preset NAT and the first IP information segment on the first network element and the corresponding relation of one or more SMFs corresponding to the NAT and the NAT, one or more SMFs can be determined by screening the first IP information, and the SMFs are used for inquiring the user context according to the private network address of the user so as to determine the only SMF for providing service for the terminal. Compared with the prior art, the method and the device for determining the SMF for providing the service for the terminal by inquiring the gateway local address pool have the advantages that the corresponding SMF can be accurately found even if the SMF does not have the local address pool, and therefore the scheme of the invention is wider in application range.

As shown in fig. 8, after planning the public network IP address pool of the NAT, the illustrated corresponding relationship between the public network IP address segment, the NAT and the SMF is obtained, where the range of the public network IP address pool is 1.2.3.4-1.2.255.255, the public network IP address in the interval of the public network IP address segment 1.2.0.1-1.2.3.9 is assigned to the NAT1, meanwhile, 2 SMFs are correspondingly provided in the NAT1, and 2 SMFs are correspondingly provided in the NAT2, so that a set of corresponding relationship between the public network IP address segment 1.2.0.1-1.2.3.9 and the NAT and SMF is formed. Wherein, each NAT corresponds to one or more SMFs.

Assuming that the terminal's public network IP address is 1.2.9.2, it can be determined that the terminal's public network IP address belongs within the public network IP address segments 1.2.4.0-1.2.9.9, corresponds to NAT2, and consists of the corresponding two SMFs.

In the determining mode 2, as shown in fig. 9, the first network element determines the second network element according to the correspondence table between the first IP information segment and the SMF, which is directly preset on the first network element.

Optionally, the first network element determines, according to a correspondence between the first IP information and the SMF, the SMF corresponding to the received first IP information.

As shown in fig. 9, after planning the public network IP address pool of the NAT, the illustrated corresponding relationship between the public network IP address segment, the NAT and the SMF is obtained, wherein the range of the public network IP address pool is 1.2.3.4-1.2.255.255, the NAT is divided into n NATs, the public network IP address in the interval of the public network IP address segment 1.2.0.1-1.2.3.9 is allocated to the NAT1, and 2 SMFs are correspondingly arranged in the NAT1, so that a set of corresponding relationships between the public network IP address segment 1.2.0.1-1.2.3.9 and the NAT and the SMF is formed, and then the middle NAT is discarded, so that the corresponding relationship between the public network IP address segment 1.2.0.1-1.2.3.9 and the corresponding SMF1 and SMF2 is formed. Wherein, each first IP information segment corresponds to one or more SMFs

If the public network IP address of the terminal is 1.2.3.4, it can be determined that the public network IP address of the terminal belongs to the public network IP address segment 1.2.3.4-1.2.3.9 according to the public network IP address 1.2.3.4 of the terminal, and it is directly determined that the terminal corresponds to two SMFs.

When one or more corresponding SMFs are determined according to first IP information of a terminal, an SMF front-end processor corresponding to the SMF determined according to the first IP information is also required to be determined

Optionally, the first network element determines, according to a correspondence between the SMF and the SMF front-end processor, the SMF front-end processor corresponding to the SMF determined according to the first IP information.

As shown in fig. 10, 2 corresponding SMFs in the NAT1 set in the drawing correspond to the SMF front-end processor 1, n-2 corresponding SMFs in the NAT2 correspond to the SMF front-end processor 2, and meanwhile, in the above process, it is determined that one or more corresponding SMFs are 2 corresponding SMFs in the NAT2 according to the first IP information of the terminal, and then the SMF front-end processor corresponding to the SMF determined according to the first IP information is the SMF front-end processor 2.

In specific implementation, the SMF front-end processor serves as a bridge between the SMF and the NEF, and takes over part of the work of the NEF, so as to reduce the burden of the NEF.

Optionally, the second network element sends the received second IP address to one or more SMFs connected to the second network element; and receiving the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address.

And when the SMF inquires the required information and returns the PCF address bound with the user context corresponding to the second IP address to the SMF front-end processor, the SMF front-end processor receives the information and feeds back the information to the NEF.

After the SMF front-end processor sends a query request to the SMF, there are two main query modes of the SMF, which will be described in detail below.

Polling mode 1, SMF queries user context by polling mode.

In a specific implementation, optionally, the second network element sends the second IP address of the terminal to the SMFs in a polling manner, and stops sending the second IP address if receiving the PCF address returned by the SMF;

As shown in fig. 11, when the SMF queries the user context, the SMF front-end processor sequentially sends a private network IP address query request message carrying the terminal to the SMF1, the SMF2, and the SMF3, and the SMF1 receives the query request message, searches the user context according to the private network IP address of the terminal, and if the corresponding user context is found, the SMF1 returns the address of the PCF bound to the user context and stops querying, otherwise, the SMF1 returns a query failure message;

after SMF1 returns the query failure message, SMF front-end processor sends the private network IP address query request message of the portable terminal to SMF2 again, SMF2 receives the query request message, searches the user context according to the private network IP address of the terminal, if the corresponding user context is found, SMF2 returns the address of PCF bound with the user context and stops querying, otherwise, SMF2 returns the query failure message;

after the SMF2 returns the query failure message, the SMF front-end processor sends a private network IP address query request message carrying the terminal to the SM3, and when the SMF3 receives the query request message, the user context is searched according to the private network IP address of the terminal, so that the corresponding user context is searched.

In addition to the polling mode, the second network element may also send the second IP address of the terminal to a plurality of SMFs, respectively, at the same time.

Optionally, the second network element simultaneously and respectively sends the second IP addresses of the terminals to the SMFs;

As shown in fig. 12, when the SMF queries the user context, the SMF front-end processor simultaneously sends a private network IP address query request message of the portable terminal to the SMF1, the SMF2, and the SMF 3.

In implementation, the second network element simultaneously and respectively sends the second IP address of the terminal to the SMFs, then receives the query result returned by each SMF, queries the PCF address bound to the user context corresponding to the second IP address of the terminal, determines that the SMF is the only SMF providing service for the user, and records the identifier of the SMF. Because the second network element simultaneously sends the query requests to all the SMFs, the SMFs do not need to wait for the SMFs to sequentially return the query results after receiving the query results returned by the SMFs, and the query time is saved.

Furthermore, the second network element may also be a BSF. If the second network element is a BSF, the overall process is similar to that when the second network element is an SMF front-end processor in the specific implementation, and the specific operation may refer to the specific embodiment where the second network element is an SMF front-end processor, and repeated details are not described again.

As shown in fig. 13, an embodiment of the present invention provides a flowchart of a PCF addressing method, where NEF is taken as a first network element, and SMF is taken as a second network element.

Step 1300, creating a PDU Session (PDU Session establishment);

step 1301, the AF request carries the second IP address of the terminal and the first IP information of the terminal (N5(AF request, including IP and optional IP domain (public IP));

step 1302, the NEF queries the SMF and the public network IP address segment and the corresponding relationship table of the SMF and the private network IP address segment in combination to find one or more SMFs (mapping IP address and IP domain (public IP) to SMF address accessing to public and private IP address assignment plane for SMFs) that manage the PDN session of the terminal;

step 1303A, querying an address of the PCF, wherein the address carries a second IP address of the terminal (acquiring PCF address for N5(IP address of UE));

step 1304, query the user context (Search the UE context);

step 1305A, returning the address of the binding PCF or returning the address of the PCF and the SMF identity (Return the result of acquiring (PCF address), and SMF id while core be registered by PCF);

step 1303B, the NEF sends an AF request to the PCF, which carries the SMF identification and the second IP address (Mapped N5(AF request), including User IP and optional SMF ID) of the User;

step 1305B, returning a query failure message (Return failure of searching the UE);

step 1308, the NEF sends an AF request to the PCF, carrying an SMF identifier and a second IP address (Mapped N5(AF request), including User IP and optional SMF ID) of the User;

step 1309, PCF performs according to the correspondence between the SMF identifier and the second IP address of the terminal

In step 1310, the PDU Session release is performed.

Wherein, SMFs 1-SMFn are n SMFs corresponding to the determined first IP information of the terminal, and assuming that SMFn is the only SMF providing service for the terminal, step 1304A and step 1305A query the SMF for the user context corresponding to the second IP address of the terminal and return the address of the PCF bound to the user context corresponding to the second IP address of the terminal, and the remaining SMFs return a query failure message.

As shown in fig. 14, an embodiment of the present invention provides a flowchart of a PCF addressing method, where NEF is taken as a first network element, and an SMF front-end processor is taken as a second network element as an example.

Step 1400, creating a PDU Session (PDU Session establishment);

step 1401, an AF request, which carries a second IP address of the terminal and first IP information of the terminal (N5(AF request, including IP and optional IP domain (public IP));

step 1402, the NEF queries the SMF and public IP address segment and the correspondence table between the SMF and private IP address segment in combination to find one or more SMFs (mapping IP address and IP domain (public IP) to SMF address accessing to public and private IP address assignment plane for SMFs) that manage the PDN session of the terminal;

step 1403, Inquiring the address of the PCF, which carries the second IP address of the terminal (acquiring PCF address for N5(IP address of UE));

step 1404A, inquiring an address of the PCF, which carries a second IP address of the terminal;

step 1404B, inquiring an address of the PCF, which carries a second IP address of the terminal;

step 1405, query the user context (Search the UE context);

step 1406A, SMFn returns the address of the binding PCF or returns the address of the PCF and the SMF identification;

step 1406B, the rest of SMFs return query failure messages;

step 1407, the SMF front-end returns the address of the binding PCF or returns the address of the PCF and the SMF id while core be retrieved PCF (Return of the resource of the PCF address);

step 1408, the NEF sends an AF request to the PCF, carrying the SMF identifier and the second IP address of the User (Mapped N5(AF request), including User IP and optional SMF ID);

step 1409, the PCF binds (Binding) according to the corresponding relationship between the SMF identifier and the second IP address of the terminal;

in step 1410, the PDU Session release is performed.

Wherein, SMFs 1-SMFn are n SMFs corresponding to the determined first IP information of the terminal, and assuming that SMFn is the only SMF providing service for the terminal, step 1404A and step 1406A query the SMF for the user context corresponding to the second IP address of the terminal and return the address of the PCF bound to the user context corresponding to the second IP address of the terminal to the SMF front-end processor, step 1406A is that the SMF front-end processor sends a query request message to the SMFs other than the SMF providing service for the terminal, and step 1406B is that the remaining SMFs return a query failure message to the SMF front-end processor. In step 1404, the SMF front-end processor sends query request messages to all SMFs, and receives query results returned by each SMF and feeds back the query results to the NEF.

Based on the same inventive concept, the embodiment of the present invention further provides a PCF addressing method, and since the devices corresponding to the method are the first network element and the second network element in the embodiment of the present invention, and the principle of the method for solving the problem is similar to that of the system, the implementation of the method can refer to the implementation of the system, and repeated details are not repeated.

As shown in fig. 15, an embodiment of the present invention provides a method for PCF addressing, where the method includes:

step 1500, the first network element determines one or more second network elements corresponding to the first IP information according to the received first IP information of the terminal;

step 1501, the first network element sends a second IP address of the terminal to the one or more second network elements;

step 1502, the first network element sends the information for implementing user session binding to PCF according to the PCF address returned by the second network element.

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the second network element is an SMF front-end processor;

As shown in fig. 16, an embodiment of the present invention provides a method for PCF addressing, where the method includes:

step 1600, the second network element receives the second IP address of the terminal sent by the first network element according to the first IP information of the terminal;

step 1601, the second network element determines a PCF address bound to a user context corresponding to a second IP address of the terminal;

step 1602, the second network element sends the PCF address to the first network element.

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the second network element is an SMF front-end processor;

As shown in fig. 17, an embodiment of the present invention provides a first network element addressed by a PCF, including: processor 1700 and transceiver 1701:

the processor 1700 is configured to perform data transmission through the transceiver, and determine one or more second network elements corresponding to first IP information according to the received first IP information of the terminal; sending a second IP address of the terminal to the one or more second network elements; and sending the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element.

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the processor 1700 is specifically configured to:

Optionally, the second network element is an SMF front-end processor; the processor 1700 is specifically configured to:

Optionally, the second network element is an SMF, and there are multiple second network elements; the processor 1700 is specifically configured to:

As shown in fig. 18, an embodiment of the present invention provides a second network element addressed by a PCF, including: processor 1800 and transceiver 1801:

the processor 1800 is configured to perform data transmission through the transceiver, and receive a second IP address of the terminal, which is sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; and sending the PCF address to the first network element.

Optionally, the processor 1800 is specifically configured to:

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the second network element is an SMF front-end processor; the processor 1800 is specifically configured to:

Optionally, there are a plurality of SMFs connected to the second network element; the processor 1800 is further configured to:

As shown in fig. 19, an embodiment of the present invention provides a first network element addressed by a PCF, where the first network element includes:

at least one processing unit 1900 and at least one storage unit 1901, wherein said storage units store program code that, when executed by said processing unit, causes said processing unit to perform the following:

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the processing unit 1900 is specifically configured to:

Optionally, the second network element is an SMF front-end processor; the processing unit 1900 is specifically configured to:

Optionally, the second network element is an SMF, and there are multiple second network elements; the processing unit 1900 is specifically configured to:

As shown in fig. 20, an embodiment of the present invention provides a second network element addressed by a PCF, where the second network element includes:

at least one processing unit 2000 and at least one memory unit 2001, wherein the memory unit stores program code which, when executed by the processing unit, causes the processing unit to perform the following processes:

Optionally, the processing unit 2000 is specifically configured to:

Optionally, the first network element is an NEF, an NRF, or an AF; and/or

Optionally, the first IP information includes part or all of the following:

Optionally, the second network element is an SMF front-end processor; the processing unit 2000 is specifically configured to:

sending the received second IP address to one or more SMFs connected with the second network element; and receiving the PCF address which is returned by the SMF and is bound with the user context corresponding to the second P address.

Optionally, there are a plurality of SMFs connected to the second network element; the processing unit 2000 is further configured to:

Embodiments of the present invention provide a computer-readable medium having a computer program stored thereon, where the program is to implement the steps of the method shown in fig. 15 and the steps of the method shown in fig. 16 when the program is executed by a processor.

The present application is described above with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the application. It will be understood that one block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the subject application may also be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the present application may take the form of a computer program product on a computer-usable or computer-readable storage medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A method for policy control function, PCF, addressing, the method comprising:

the first network element determines one or more second network elements corresponding to the first IP information according to the received first network protocol IP information of the terminal;

the first network element sends the information for realizing the user session binding to the PCF according to the PCF address returned by the second network element;

the second network element is an SMF front-end processor; the method for determining one or more second network elements corresponding to the first IP information by the first network element according to the received first IP information of the terminal comprises the following steps: the first network element determines the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determines the SMF corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the SMF; or determining the SMF corresponding to the received first IP information according to the corresponding relation between the first IP information and the SMF; the first network element determines the SMF front-end processor corresponding to the SMF determined according to the first IP information according to the corresponding relation between the SMF and the SMF front-end processor; or

The second network element is an SMF, and a plurality of second network elements are provided; the sending, by the first network element, the second IP address of the terminal to the one or more second network elements includes: the first network element sends the second IP addresses of the terminals to a plurality of second network elements in a polling mode, and stops sending the second IP addresses if the PCF addresses returned by the second network elements are received; or the first network element simultaneously and respectively sends the second IP addresses of the terminals to a plurality of second network elements.

2. The method of claim 1, wherein the first network element is a network open function (NEF), a network element registration function (NRF), or a service function (AF).

3. The method of claim 1,

the first IP information includes part or all of the following:

the method comprises the steps of obtaining a public network IP address, a public network IP address mask, a name of NAT corresponding to the public network IP address, information representing the name of a public network IP domain and information representing a network element NF where a user is located.

4. The method as claimed in claim 2, wherein the determining, by the first network element, one or more second network elements corresponding to the first IP information according to the received first IP information of the terminal, comprises:

5. A method for PCF addressing, the method comprising:

the second network element sends the PCF address to the first network element;

the second network element is an SMF front-end processor; the determining, by the second network element, the PCF address bound to the user context corresponding to the second IP address of the terminal includes: the second network element sends the received second IP address to one or more SMFs connected with the second network element; the second network element receives the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address; or

A plurality of SMFs connected with the second network element are provided; the second network element sends the received second IP address to one or more SMFs connected to the second network element, including: the second network element sends the second IP address of the terminal to the SMFs in a polling mode, and stops sending the second IP address if receiving the PCF address returned by the SMFs; or the second network element simultaneously and respectively sends the second IP addresses of the terminals to the SMFs.

6. The method of claim 5, further comprising:

7. The method according to claim 5 or 6, wherein the first network element is a network open function, NEF, or NRF, or AF.

8. The method of claim 5, wherein the first IP information comprises part or all of the following:

9. A PCF addressed first network element, comprising: a processor and a transceiver:

the processor is configured to perform data transmission through the transceiver, and determine one or more second network elements corresponding to first IP information according to the received first IP information of the terminal; sending a second IP address of the terminal to the one or more second network elements; sending information for realizing user session binding to the PCF according to the PCF address returned by the second network element;

the second network element is an SMF front-end processor; the processor is specifically configured to: determining the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determining the SMF corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the SMF; or determining the SMF corresponding to the received first IP information according to the corresponding relation between the first IP information and the SMF; determining the SMF front-end processor corresponding to the SMF determined according to the first IP information according to the corresponding relation between the SMF and the SMF front-end processor; or

The second network element is an SMF, and a plurality of second network elements are provided; the processor is specifically configured to: sending a second IP address of the terminal to a plurality of second network elements in a polling mode, and stopping sending if receiving a PCF address returned by the second network elements; or simultaneously and respectively sending the second IP addresses of the terminals to a plurality of second network elements.

10. The first network element of claim 9, wherein the first network element is a network open function (NEF) or NRF or AF.

11. The first network element of claim 9, wherein the first IP information includes some or all of:

12. The first network element of claim 10, wherein the processor is specifically configured to:

13. A PCF addressed second network element, comprising: a processor and a transceiver:

the processor is used for transmitting data through the transceiver and receiving a second IP address of the terminal, which is sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; sending the PCF address to the first network element;

the second network element is an SMF front-end processor; the processor is specifically configured to: sending the received second IP address to one or more SMFs connected with the second network element; receiving the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address; or

A plurality of SMFs connected with the second network element are provided; the processor is further configured to: sending a second IP address of the terminal to the SMFs in a polling mode, and stopping sending if receiving PCF addresses returned by the SMFs; or simultaneously and respectively sending the second IP address of the terminal to a plurality of SMFs.

14. The second network element of claim 13, wherein the processor is specifically configured to:

15. The second network element according to claim 13 or 14, wherein the first network element is a network open function, NEF, or NRF, or AF.

16. The second network element of claim 13, wherein the first IP information includes some or all of:

17. A first network element addressed by a PCF, the first network element comprising:

determining one or more second network elements corresponding to first IP information according to the received first IP information of the terminal; sending a second IP address of the terminal to the one or more second network elements; sending information for realizing user session binding to the PCF according to the PCF address returned by the second network element;

the second network element is an SMF front-end processor; the processing unit further performs the following processes: determining the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the first IP information, and determining the SMF corresponding to the NAT corresponding to the received first IP information according to the corresponding relation between the NAT and the SMF; or determining the SMF corresponding to the received first IP information according to the corresponding relation between the first IP information and the SMF; determining the SMF front-end processor corresponding to the SMF determined according to the first IP information according to the corresponding relation between the SMF and the SMF front-end processor; or

The second network element is an SMF, and a plurality of second network elements are provided; the processing unit further performs the following processes: sending a second IP address of the terminal to a plurality of second network elements in a polling mode, and stopping sending if receiving a PCF address returned by the second network elements; or simultaneously and respectively sending the second IP addresses of the terminals to a plurality of second network elements.

18. A PCF addressed second network element, the second network element comprising:

receiving a second IP address of the terminal sent by the first network element according to the first IP information of the terminal; determining a PCF address bound with a user context corresponding to a second IP address of the terminal; sending the PCF address to the first network element;

the second network element is an SMF front-end processor; the processing unit further performs the following processes: sending the received second IP address to one or more SMFs connected with the second network element; receiving the PCF address which is returned by the SMF and is bound with the user context corresponding to the second IP address; or

A plurality of SMFs connected with the second network element are provided; the processing unit further performs the following processes: sending a second IP address of the terminal to the SMFs in a polling mode, and stopping sending if receiving PCF addresses returned by the SMFs; or simultaneously and respectively sending the second IP address of the terminal to a plurality of SMFs.

19. A computer-readable medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 4 or the steps of the method according to any one of claims 5 to 8.