WO2009056046A1

WO2009056046A1 - A method for session termination

Info

Publication number: WO2009056046A1
Application number: PCT/CN2008/072792
Authority: WO
Inventors: Shiyong Tan; Weihua Wei; Xiaoyan Shi
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-10-25
Filing date: 2008-10-23
Publication date: 2009-05-07
Also published as: CN101420361A

Abstract

A method for session termination involves: a client receives a request message including an extended cause value parameter from a server; the client gets the cause value parameter from the request message, indicates the server to terminate a session according to the cause value parameter. A system for session termination that involves a client and a server is disclosed in embodiment. A client and a server are also disclosed in the embodiment.

Description

Method, system and server, client end of session termination

This application claims priority to Chinese Patent Application No. 200710165403. K, entitled "Method, System and Server for Session Termination", which is filed on October 25, 2007. This is incorporated herein by reference.

Technical field

The present invention relates to the field of communications, and in particular, to a method, system, server, and client for terminating a session.

Background technique

A session refers to a connection relationship between a user terminal (UE, User Equipment) and an external network, such as the Internet. The connection relationship can be identified by the IP address of the UE or the identifier of the UE. For example, In an IP-Connected Access Network (IP-CAN), if an IP address is assigned to a terminal and can be recognized by an external network, an IP-CAN session is said to exist.

In the process of the tongue, for some reason, it is necessary to use the ASR (Abort-Session-Request) message to terminate the tongue, so as to release the resources occupied by the tongue in time. FIG. 1 is a schematic diagram of a UE-initiated IP-CAN session and an AF session release process in the prior art. FIG. 1 adopts a PCC architecture defined by the 3GPP, and mainly includes: an application function entity (AF, Application Function), and a gateway (GW, Gateway). Policy and Charging Enforcement Function (PCEF) and Policy Control and Charging Rules Function (PCRF).

The PCRF is mainly used to determine the policy corresponding to the user's access to the network, the operator's policy, and the current policy of the user from the AF, and provide the determined policy to the PCEF. The PCEF performs the PCRF delivery or The specified policy is provided. The AF dynamically provides session information of the application layer to the PCRF, and the PCRF dynamically generates or modifies the corresponding rule according to the information. As shown in Figure 1, the current method of terminating the session mainly includes the following steps:

Step 101: The PCEF receives the IP-CAN [tonal release request message] initiated by the UE.

The IP-CAN (Telecom Data Release) request message in the present step may be specifically a deletion request message for the last Packet Data Protocol (PDP) context for the Packet Radio System (GPRS). Step 102: The PCEF sends a CCR (Credit-Control-Request) message to the PCRF to the PCRF.

In this step, the PCEF sends a CCR message of the Diameter protocol, informing the PCRF to release the IP-CAN.

The interface between PCRF and PCEF is the Gx interface, which allows the PCRF to dynamically control the PCC rules enforced on the PCEF. The Gx interface uses the Diameter protocol defined by the IETF.

Step 103: The PCRF searches for the binding correspondence between the IP-CAN^ tongue and the AF^ tongue.

Step 104: The PCRF sends a CCA (Credit-Control- Answer) message to the PCEF.

In this step, the PCRF sends a CCA message to respond to the notification of releasing the IP-CAN session. Step 105: The PCEF sends an IP-CAN [tonal release response message" to the UE.

The IP-CAN session release response message in this step may be specifically for the GPRS to delete the PDP context response message of step 101.

For each AF session associated with the IP-CAN session, perform the release steps of steps 106 to 109:

Step 106: The PCRF sends an Abort-Session-Request (ASR) message to the AF.

In this step, the PCRF acts as a server and sends an ASR message of the Diameter protocol to the AF as the client to request termination.

The interface between the AF and the PCRF is an Rx interface, which is used by the AF to deliver application layer related information.

The Rx interface also uses the Diameter protocol defined by the IETF.

The Diameter protocol belongs to the protocol of the client server mode. The Diameter client and the Diameter server can exchange a series of information, and a series of information interactions from initiation to termination is called a Diameter session. The termination of the Diameter session is completely determined by the Diameter client. The Diameter server can issue the termination session request first. When the Diameter client agrees to terminate the request, it will respond to the termination response, and then the Diameter client will issue a session termination request. The Diameter server ends the user session, otherwise the session is still maintained.

Step 107: The AF sends a terminate session response (ASA, Abort-Session-Answer) message to the PCRF. In this step, the AF sends an ASA message of the Diameter protocol to the PCRF as a response to the ASR message of the Diameter protocol.

Step 108: The AF sends a session termination request (STR, Session-Termination-Request) message to the PCRF.

In this step, the AF sends an STR message of the Diameter protocol to the PCRF, informing the PCRF to terminate the AF session.

Step 109: The PCRF sends a STA (Session, Session-Termination- Answer) message to the AF.

In this step, the PCRF sends the STA message of the Diameter protocol to the AF to the AF, and the AF^ tongue terminates.

In the process of terminating the session shown in FIG. 1, an IP-CAN session is terminated by deleting all PDP contexts. Of course, the ASR/ASA message of the Diameter protocol and the STR/STA can also be used on the Gx interface between the PCRF and the PCEF. Message to release the IP-CAN session.

Currently, there are many reasons for terminating a session. For example, due to insufficient PCRF resources or due to device management, the session is released. Currently, the reason for the lack of PCRF resources and device management cannot be indicated in the termination session. Therefore, the corresponding processing cannot be given in time. For example, according to the Diameter protocol, the PCEF acting as the Diameter client may not initiate the session release process after receiving the ASR message. Therefore, when the PCRF fails or the device management needs to release the session, the PCEF cannot release the IP-CAN tongue in time.

In summary, the current method of terminating the session cannot indicate the reasons for terminating the session, and the user experience is poor.

Summary of the invention

Embodiments of the present invention provide a method for terminating a session, which can improve a terminating session mechanism, thereby enhancing a user experience.

Embodiments of the present invention also provide a system for terminating a session, which system can improve the termination session mechanism, thereby enhancing the user experience.

Embodiments of the present invention additionally provide a server that can improve the termination session mechanism, thereby enhancing the user experience.

An embodiment of the present invention further provides a client, which can improve the termination session mechanism, And enhance the user experience.

In order to achieve the above objective, the technical solution of the embodiment of the present invention is specifically implemented as follows: the client receives a request message from the server that carries the extended cause value parameter, and the client obtains the cause value parameter from the request message. Instructing the server to terminate the session based on the extended cause value parameter.

A system for terminating a tongue, the system comprising:

a server, configured to send a request message carrying an extended cause value parameter;

The client, configured to obtain the cause value parameter from the request message sent by the server, and instruct the server to terminate the tongue according to the cause value parameter.

A server, the server comprising:

a receiving module, configured to receive a session termination indication from the client;

a sending module, configured to send a request message carrying an extended cause value parameter, where the extended cause value parameter indicates that the user service quality requirement cannot be met due to a PCRF failure, a device management change, a user subscription change, a PCEF failure, or a session release The AF session is released due to the release of the IP-CAN session.

A client said client includes:

Obtaining an ear parameter for obtaining a reason value parameter indicating that the user service quality requirement cannot be satisfied due to a PCRF failure, a device management reason, a user subscription change, a PCEF failure, or a request due to IP-CAN The cause value parameter of the release of the tongue resulting in AF release of the tongue;

And a processing module, configured to instruct the server to terminate the session according to the reason value parameter obtained by the obtaining module.

The method, the system, the server, and the client of the session termination provided by the embodiment of the present invention can indicate the PCRF failure, the device management, or the user subscription, and the QoS is not satisfied by extending the cause value parameter carried in the protocol message. The reason for the termination, so that the corresponding processing can be performed in time according to the reason, the termination session mechanism can be improved, and the user experience is enhanced.

DRAWINGS

1 is a schematic flowchart of a method for terminating a session adopted in the prior art;

2 is a schematic flow chart of a method for terminating a tongue used in an embodiment of the present invention; 3 is a schematic flowchart of a method for terminating a session in a first embodiment of the present invention;

4 is a schematic flowchart of a method for terminating a session in a second embodiment of the present invention;

FIG. 5 is a schematic flowchart of a method for terminating a session in a third embodiment of the present invention; FIG.

FIG. 6 is a schematic structural view of a device for terminating the tongue used in the embodiment of the present invention.

detailed description

In order to make the objects, technical solutions and advantages of the present invention more comprehensible, the present invention will be further described in detail below with reference to the accompanying drawings.

The method for terminating the session provided by the embodiment of the present invention is: the client receives the ASR message from the server, and the ASR message carries the extended cause value parameter; the client obtains the cause value parameter from the ASR message, according to the The reason value parameter indicates that the server terminates the tongue.

FIG. 2 is a schematic flow chart of a method for indicating a reason for termination of a tongue according to an embodiment of the present invention. As shown in Figure 2, the following steps are specifically included:

Step 201: The client receives an ASR message from the server, where the ASR message carries an extended reason value parameter.

In this step, the client receives an ASR message from the server, and the ASR message may be

The ASR message of the Diameter protocol may also be an ASR message of other protocols, for example, an ASR message of the Radius protocol.

For the Gx interface between the PCEF and the PCRF, the ASR message in this step carries the extended cause value parameters including:

Device Management Reason (ADMINISTRATION— REASON): Indicates the reason value parameter for IP-CAN session release due to device management requirements.

Server failure ( SERVER_ MALFUNCTION ): Indicates the cause value parameter of the IP-CAN session release due to a PCRF failure.

Other reasons ( OTHER — REASONS ): Indicates the IP-CAN session release caused by other reasons. For the Rx interface between the AF and the PCRF, this step carries the extended cause value parameters in the ASR message, including:

IP-CAN [SESSION- RELEASED]: Indicates the reason value parameter for the PCRF to release the AF session due to the release of the IP-CAN session.

Device management reason ( ADMINISTRATION - REASON ): Indicates the need for device management The cause value parameter of the AF ^ tongue release to be caused.

The service quality is not satisfied (QOS-CANNOT-BE-AUTHORISE): It is mainly used to release the reason value parameter of the AF session when the user signing changes cannot meet the requirements of the user Qos.

Server failure ( SERVER_ MALFUNCTION ): Indicates the cause value parameter of the AF session release due to a failure of the PCRF.

PCEF failure (PCEF_MALFUNCTION): Indicates the cause value parameter for the AF session release due to a PCEF failure.

Other causes ( OTHER — REASONS ): Indicates AF tongue release due to other causes. Of course, those skilled in the art will readily appreciate extending other protocol messages, such as extending the above types of cause value parameters in client/server mode protocol messages.

Step 202: The client obtains a cause value parameter from the ASR message, and according to the cause value parameter, instructs the server to terminate the session.

In the protocol message used by the Gx interface or the Rx interface, the reason for the termination of the tongue is indicated by carrying one of the above-mentioned cause value parameters. Of course, in the message used by other interfaces, by carrying the above-mentioned cause value parameter, the reason for the termination of the session is indicated.

In the embodiment of the present invention, by extending the cause value parameter carried in the ASR message, it is possible to indicate a PCRF fault, a PCEF fault, a device management, or a user subscription change, and no longer satisfy the reasons for termination of multiple sessions such as QoS, thereby being able to The corresponding processing is performed in time, for example, promptly instructing the PCRF to terminate the IP-CAN session or the AF session, thereby improving the termination mechanism and enhancing the user experience. The following is a detailed description of several processes for terminating the session using the extended cause value parameter.

FIG. 3 is a schematic flowchart of a method for terminating a session in a first embodiment of the present invention. In this embodiment, the device management initiates an IP-CAN session and an AF session release application instance, that is, after the IP-CAN session between the PCEF and the PCRF and the AF session between the PCRF and the AF have been established, the device management on the PCRF needs to be released. A user IP-CAN session and an AF session, at which time the ASF message is sent by the PCRF to the PCEF and AF respectively to initiate the release of the IP-CAN session and the AF session. Before the release process shown in Figure 3, the cause value parameters ADMINISTRATION- REASON ( 1 ) and ADMINISTRATION - REASON ( 3 ) that characterize the device management cause the tongue release are extended in the Diameter protocol message used by the Gx interface and the Rx interface. ).

Step 301: The PCRF sends a message carrying the characterization device management reason to the PCEF. ASR message due to value parameter.

In this embodiment, the device management on the PCRF needs to release the user session connection, the PCRF sends the ASR message of the Diameter protocol to the PCEF, and the ASR message carries the Abort-Cause AVP, and takes the value as ADMINISTRATION-REASON ( 1), mainly indicating the release of IP-CAN sessions due to the need for device management.

Step 302: The PCEF sends an ASA message to the PCRF.

Step 303: The PCEF sends an STR message to the PCRF.

In this embodiment, the PCEF uses the STR message to indicate that the PCRF releases the IP-CAN session according to the cause value parameter carried in the ASR message.

Step 304: The PCRF sends a STA message to the PCEF.

In this embodiment, after the IP-CAN^ tongue release is completed, the PCRF sends a STA message to the PCEF. Step 305: The PCRF determines the affected AF session according to the binding relationship.

For each affected AF session, perform the following steps:

Step 306: The PCRF sends an ASR message carrying the cause value parameter indicating that the device management causes the session release to the AF.

The PCRF sends an ASR message to the AF. The message carries the Abort-Cause AVP, where the value is ADMINISTRATION- REASON ( 3 ), indicating that the PCRF releases the AF session due to device management.

Step 307: The AF sends an ASA message to the PCRF.

Step 308: The AF sends the STR message to the PCRF.

In this embodiment, the AF uses the STR message to instruct the PCRF to release the AF^ tongue according to the reason value parameter carried in the ASR message carrying.

Step 309: The PCRF sends a STA message to the AF.

In this embodiment, after the AF session is released, the STA message is sent.

In this embodiment, by carrying the reason parameter value indicating that the device is released due to the management of the device in the ASR message, the PCEF can release the IP-CAN session in time after receiving the message.

FIG. 4 is a schematic flowchart of a method for terminating a session in a second embodiment of the present invention. In this embodiment, the PCRF failure causes an IP-CAN session and an AF session release application instance. When the PCRF fails, the PCRF needs to release a certain user IP-CAN^ tongue and AF session. Different from the first example: When there is only one IP-CAN bearer in the IP-CAN session, after receiving the ASR message sent by the PCRF, the PCEF releases the IP-CAN session by sending the Diameter CCR to the PCRF to release the last IP-CAN bearer. Prior to the session release procedure shown in FIG. 4, the cause value parameter characterizing the PCRF failure causing the tongue release is extended in advance in the Diameter protocol message used by the Gx interface and the Rx interface.

Step 401: The PCRF sends an ASR message carrying the cause value parameter indicating that the PCRF failure causes the session release to the PCEF.

Because the PCRF fault needs to release the user tongue connection, the PCRF sends the Diameter protocol ASR message to the PCEF with the Abort-Cause AVP, where the value is

SERVER—MALFUNCTION ( 3 ), mainly indicates the release of IP-CAN session due to PCRF failure.

Step 402: The PCEF sends an ASA message to the PCRF.

Step 403: Release the IP-CAN bearer between the PCEF and the UE.

In this embodiment, there is only one IP-CAN bearer in the IP-CAN session, and the PCEF initiates the release of the IP-CAN bearer.

Step 404: The PCEF sends a CCR message to the PCRF.

In this embodiment, the CCR message is used to instruct the PCRF to release the IP-CAN session.

Step 405: The PCRF sends a CCA message to the PCEF.

In this embodiment, after the IP-CAN session is released, the PCRF sends a CCA message to the PCEF. Step 406: The PCRF determines the affected AF session according to the binding relationship.

For each affected AF session, perform the following steps:

Step 407: The PCRF sends an ASR message carrying the cause value parameter indicating that the PCRF fault causes the tongue release.

In this embodiment, the PCRF sends an ASR message to the AF, and the message carries an Abort-Cause AVP, where the value is ADMINISTRATION-REASON (5), indicating that the PCRF releases the AF session because of a PCRF failure.

Steps 408 to 410 are the same as steps 307 to 309, and are not mentioned here.

In this embodiment, when the step 403 is executed, the PCEF may also prompt the user for the reason for the termination of the session, such as "terminating the service due to failure", etc., and the PCEF may also count the reason for the termination of the tongue. In this embodiment, by carrying the reason value parameter of the session release caused by the PCRF failure in the ASR message, the PCEF can release the IP-CAN session in time after receiving the message.

FIG. 5 is a schematic flow chart of a method for terminating a tongue according to a third embodiment of the present invention. This embodiment is an example in which the change of the subscriber subscription information causes the IP-CAN session and the AF session to be released, assuming that the IP-CAN session and the AF session have been established. As the user subscription information changes, the current IP-CAN bearer QoS and the subscription QoS are inconsistent. At this time, the PCRF needs to release the user AF session and the affected IP-CAN bearer. Before the session termination process shown in FIG. 5, the reason value parameter QOS_CANNOT_BE_AUTHORISE which characterizes the release of the session due to the user's service quality requirement due to the user subscription change is extended in the Diameter protocol message used by the Rx interface. (2), the specific steps are as follows: Step 501: User subscription information changes.

In this embodiment, the user subscription information is changed, and the subscription information base (SPR) sends the updated subscription information to the PCRF. The QoS in the new subscription information of the user is inconsistent with the subscription QoS in the current IP-CAN bearer. Different from the quality of service level (QCI), it may also not meet other QoS requirements. The PCRF needs to release the AF session and the corresponding IP-CAN bearer, that is, release the corresponding bearer by deleting the PCC rule.

Step 502: The PCRF sends a re-authentication request (RAR, Re-Auth-Request) message to the PCEF, where the RAR message carries a cause value indicating that the PCRF failure causes the tongue to be released.

In this embodiment, the RAR message carries a PCC rule that needs to be deleted.

Step 503: The PCEF sends a re-authentication response (RAA, Re-Auth- Answer) message to the PCRF. In this embodiment, after the PCEF deletes the PCC rule, the PCEF sends an RAA message to the PCRF.

Step 504: The PCEF initiates release of the IP-CAN bearer to the terminal.

Step 505: The PCEF sends a CCR message to the PCRF.

In this embodiment, the CCR message is used to indicate the release of the IP-CAN bearer.

Step 506: The PCRF sends a CCA message to the PCEF.

Step 507: The PCRF determines the affected AF session according to the binding relationship.

For each affected AF session, perform the following steps:

Step 508: The PCRF sends an ASR message to the AF.

In this embodiment, the ASR message sent by the PCRF carries the reason value parameter indicating that the user's service quality requirement cannot be satisfied due to the user subscription change: QOS—CANNOT—BE – AUTHORISE ( 2 ), indicating that the user's IP-CAN session is released when the user's subscription change fails to meet the user's QoS requirements.

Steps 509 to 511 are the same as steps 307 to 309, and are not mentioned here.

In this embodiment, the reason value parameter indicating that the session is released due to the failure to satisfy the user service quality requirement due to the user subscription change is carried in the ASR message, so that the user is sent to the user as the prompt information through the PCEF, so that the user can promptly release the session. User-friendly.

FIG. 6 is a system for indicating the reason for termination of a tongue according to an embodiment of the present invention. The system includes: a server 610, which sends an ASR message, where the ASR message carries an extended cause value parameter; and the client 620 sends an ASR message from the server. Obtaining a cause value parameter, according to the cause value parameter, instructing the server 610 to terminate the session.

Server 610 includes:

Receiving module 611, receiving a session termination indication from the client;

The sending module 612 sends an ASR message, where the ASR message carries a function that indicates that the user is unable to meet the user service quality requirement due to the policy charging rule function entity PCRF failure, device management reason, user subscription change, and the policy and charging execution entity PCEF failure causes the session to be released. The cause value parameter or the cause value parameter of the AF session release due to the IP connection of the IP connection access network IP-CAN.

Client 620 includes:

The obtaining module 621 obtains, from the ASR message sent by the server, that the session is released due to the failure of the policy charging rule function entity PCRF, the device management reason, the user subscription change, the user service quality requirement, and the policy and charging execution entity PCEF failure. The cause value parameter or the cause value parameter of the AF session release due to the release of the IP-CAN session of the IP connection access network;

The processing module 622, according to the reason for the termination of the session indicated by the cause value parameter obtained by the module 621, performs corresponding processing.

When the client 610 is a PCEF and the server 620 is a PCRF, the processing module 622 instructs the PCRF to terminate the IP-CAN.

The client 620 can also include: a prompting module 623, the prompting module 623 prompting the user for the reason for the termination of the session.

The client 620 may further include: a statistics module (not shown), and the statistics module may count the reason for the termination of the session. When the client 610 is an AF and the server 620 is a PCRF, the processing module 622 instructs the PCRF to terminate the AF^ tongue.

The above description is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalents, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Rights request

A method for terminating a session, the method comprising:

The client receives a request message from the server that carries the extended cause value parameter; the client obtains the cause value parameter from the request message, and instructs the server to terminate the session according to the cause value parameter.

2. The method according to claim 1, wherein the extended cause value parameter comprises:

Characterizing the cause value parameter of the session release due to the PCRF fault of the functional entity of the policy charging rule, characterizing the cause value parameter of the tongue release due to device management reasons,

Characterizing the reason value parameter that causes the session to be released due to the user's subscription change being unable to meet the user's quality of service requirements,

A reason value parameter that characterizes the release of the session due to a failure of the policy and charging enforcement entity PCEF, or a factor value parameter that characterizes the release of the AF^ tongue due to the IP-CAN tongue release of the IP connection access network.

3. The method according to claim 2, wherein the server is a PCRF, and the client is a PCEF.

The instructing the server to terminate the session comprises: the PCEF instructing the PCRF to release an IP-CAN session.

4. The method of claim 3 wherein said instructing PCRF to release an IP-CAN session comprises:

After releasing the last IP-CAN bearer, the PCEF uses the credit control request message to indicate that the PCRF releases the IP-CAN session.

The method according to claim 3, wherein the indicating server further comprises one or two combinations after terminating the session: prompting the user to count the reason for the termination of the session.

The method according to claim 3, wherein the request message carrying the extended cause value parameter comprises a suspension session request ASR message and a re-authentication request RAR message.

The method according to claim 1, wherein the server is a PCRF, and the i1⁄2 client is an AF.

The instructing the server to terminate the session includes: the AF instructing the PCRF to release the AF session.

8. The method according to claim 7, wherein the request message carrying the extended cause value parameter comprises an abort session request ASR message.

9. A system for terminating a tongue, wherein the system comprises:

The system according to claim 9, wherein the server comprises: a receiving module, configured to receive a session termination indication from the client;

a sending module, configured to send a request message carrying an extended cause value parameter, where the extended cause value parameter indicates that the user service quality requirement cannot be met due to a PCRF failure, a device management change, a user subscription change, a PCEF failure, or a session release The AF^ tongue is released due to the release of the IP-CAN session.

The system according to claim 9, wherein the client comprises: an ear module for obtaining a characterization from the request message sent by the server, due to a PCRF failure, a device management reason, The user is not able to meet the user service quality requirement, and the PCEF processing module is configured to instruct the server to terminate the tongue according to the reason value parameter obtained by the obtaining module.

The system according to claim 11, wherein the client is a PCEF, and the server is a PCRF.

The processing module instructs the PCRF to terminate the IP-CAN session.

The system according to claim 12, wherein the client further comprises: a prompting module, configured to prompt the user for the reason for the termination of the tongue.

The system according to claim 12 or 13, wherein the client further comprises:

A statistics module that is used to count the cause of session termination.

The system according to claim 12, wherein the request message carrying the extended cause value parameter comprises a suspension session request ASR message and a re-authentication request RAR message.

The system according to claim 11, wherein the client is an AF, The server is a PCRF,

The processing module instructs the PCRF to terminate the AF session.

The system according to claim 16, wherein the request message carrying the extended cause value parameter is an abort session request ASR message.

18. A server, wherein the server comprises:

The server according to claim 18, wherein the server is a PCRF.

The server according to claim 18, wherein the request message carrying the extended factor value parameter comprises a suspension session request ASR message and a re-authentication request RAR message.

A client, wherein the client includes:

The obtaining module is configured to obtain, from the request message sent by the server, a reason value parameter that is unable to satisfy the user service quality requirement due to a PCRF fault, a device management change, a user subscription change, a PCEF fault, and a session release factor, or an IP-CAN tongue release The cause value parameter that causes the AF ^ tongue to be released;

And a processing module, configured to instruct the server to terminate the tongue according to the reason value parameter acquired by the acquiring module.

The client according to claim 21, wherein the client is a PCEF, and the server is a PCRF.

The processing module instructs the PCRF to terminate the IP-CAN session.

The client according to claim 22, wherein the client further comprises:

A prompt module, configured to prompt the user for the reason for the termination of the session.

The client according to claim 22 or 23, wherein the client further comprises:

A statistics module that is used to count the cause of session termination.

The client according to claim 22, wherein the request message comprises an abort session request ASR message and a re-authentication request RAR message.

The client according to claim 21, wherein the client is an AF, and the server is a PCRF.

The processing module instructs the PCRF to terminate the AF session.

The client according to claim 26, wherein the request message carrying the extended factor value parameter comprises an abort session request ASR message.