WO2013078849A1 - Method, system and apparatus for disaster tolerant serving call session control function (s-cscf) to restore back - Google Patents

Abstract

Disclosed are a method, system and apparatus for disaster tolerant S-CSCF to restore back. The method comprises: when the terminal UE is going to be restored back to the original S-CSCF, if the UE is busy on a call service, the operation will not be implemented. The method further comprises: after receiving a registration request message from a UE, the Interrogating Call Session Control Function (I-CSCF) restores the UE requesting for the registration back to the original S-CSCF that has recovered; after receiving a Registration-Termination-Request (RTR) message, if the current S-CSCF determines that the UE is busy on a call service, the local user data will not be removed until the call is released. In this invention, established call services will not be released while UE is restoring back. Thereby the call loss caused by restoring back can be avoided and user experiences might be improved greatly.

Description

 Method, system and device for reversing service call session control function entity

 The present invention relates to a disaster recovery technology, and more particularly to a method, system and device for a disaster recovery service call session control function entity in an IP Multimedia subsystem (IMS, IP Multimedia subsystem). Background technique

 The IP Multimedia subsystem (IMS) is a standard for next-generation networks defined by the 3rd Generation Partnership Project (3GPP). Its distinctive feature is the use of Session Initiation Protocol (SIP). The system, communication and access are independent, and can have multiple media service control functions and bearer separation, call and session separation, application and service separation, service and network separation, and mobile network and Internet service integration.

The proposal of IMS complies with the trend of communication network convergence development. FIG. 1 is a schematic diagram of an existing IMS network architecture. As shown in FIG. 1, the main functional entities in the IMS system include: a Proxy Call Session Control Function (P-CSCF), and an access gateway control function entity ( AGCF, Access Gateway Control Function), Inter-Calling Call Session Control Function (I-CSCF), Serving Call Session Control Function (S-CSCF, Serving Call Session Control Function), Home Subscriber Server ( the connection between the HSS, Home Subscriber Server) ₀ NE above may specifically refer to FIG. 1, since the network element functions and connection relations of prior art are omitted here and the function of each network element specific Connection relationship, etc. For the above network element functions and their connection relationships, refer to the relevant standards of the IMS system.

In order to improve the level of operation, operators must provide users with high-quality, uninterrupted service. When the S-CSCF network element of the current service is unavailable, the network needs to provide an effective DR mechanism and switch services to other available devices as much as possible to minimize the loss of services to users. After the S-CSCF version is upgraded or the fault is rectified, you need to revert the user service back to the device to reduce the load on other devices.

 Figure 2 is a flowchart of the disaster recovery switching of the existing S-CSCF. As shown in Figure 2, the S-CSCF disaster recovery process includes the following steps:

 S202, the terminal (UE, User Equipment) has successfully registered on the S-CSCF1; S204, the UE sends a call request (invite) message to the P-CSCF network element;

 S206. After receiving the call request message, the P-CSCF forwards the call request message to the home S-CSCF1 according to the locally saved registration information.

 S208, because the S-CSCF1 fails, the S-CSCF1 cannot receive or cannot respond to the call request message, and the P-CSCF sends a call request message to the I-CSCF, where the route header field carries the orig parameter; The P-CSCF can detect the S-CSCF state through the OPTIONS. For the detection mode, refer to the IMS-related protocol. The implementation details are not described here.

 S210. After receiving the call request message, the I-CSCF sends an S-CSCF Location Request (LIR, Location-Info-Request) message to the HSS network element.

 S212, after receiving the call request message, the HSS returns an S-CSCF Location Response (LIA, Location-Info-Answer) message to the I-CSCF network element according to the locally recorded S-CSCF information, where the response message carries the user registration. The home S-CSCF host name;

 S214. After receiving the LIA response message, the I-CSCF obtains the S-CSCF host name, finds that the user is registered with the S-CSCF1 abnormality, and sends an LIR request message to the HSS network element, where the request message indicates that the HSS returns the S-CSCF. ;

S216, after receiving the LIR request message, the HSS returns a LIA response message to the I-CSCF network element, where the response message carries the S-CSCF capability set. S218, after receiving the LIA response message, the I-CSCF obtains the available S-CSCF host information according to the S-CSCF capability information and the S-CSCF host status, and sends a call request message to the S-CSCF2;

 S220: After receiving the call request message, the S-CSCF2 finds that there is no user data locally, and sends a User Configuration Request (SAR, Server-Assignment-Request) message to the HSS.

 S222, the HSS returns an SAA response message to the S-CSCF2, where the response message carries the subscription information of the user, and also includes the registration and subscription information of the backup (provided that the user has already registered with the HSS and backed up the subscription information);

 S224, the S-CSCF2 continues the call processing, and the foregoing process completes the S-CSCF disaster recovery switching. Subsequent UE registrations are also registered to the available S-CSCF2. Switching can reduce the loss of user/service failures caused by equipment/network failures. However, in consideration of equipment load and operation and maintenance requirements, when the faulty equipment is restored, it needs to be reversed in time. Figure 3 is a flow chart of the current S-CSCF disaster recovery. As shown in Figure 3, the S-CSCF disaster recovery process includes the following steps:

 S302. The UE is already registered on the S-CSCF2 according to the disaster recovery switching mechanism.

 S304. The UE sends a refresh registration request message to the P-CSCF.

 S306. When the P-CSCF receives the refresh registration request message, the P-CSCF searches for the I-CSCF through a Domain Name System (DNS, Domain Name System) query or other manner, and forwards the registration request message to the I-CSCF.

 S308, when the S-CSCF1 has been restored, and based on the automatic or manual rewinding mechanism, the user that belongs to the S-CSCF2 needs to be re-selected to the S-CSCF1, and then returned to the original home S-CSCF1;

S310: The I-CSCF sends a User Authentication Request (UAR) message to the HSS, requesting the HSS to return the S-CSCF capability set information; S312, the HSS returns a user authentication response to the I-CSCF (UAA, User-Authorization- Answer message, the response message contains the assignment to the user S-CSCF capability set information, the capability set information actually includes the home S-CSCF list information;

S314, the I-CSCF selects an appropriate S-CSCF host according to the UAA response message returned by the HSS, and sends a registration request message to the selected S-CSCF1;

 S316, the S-CSCF1 sends a user configuration request SAR message to the HSS.

 S318, the HSS returns a user configuration response SAA message to the S-CSCF1, where the SAA message carries the user subscription data;

 S320: After receiving the SAA message, the S-CSCF saves the user data, constructs and sends a registration success response message 200OK. The general commercial network also has an authentication process. Since the authentication process is an existing technology, the process is repeated in S304-S314, and the implementation details are not repeated here;

 S322, the I-CSCF forwards the registration success response message to the P-CSCF;

 S324: The P-CSCF forwards the registration success response message to the UE.

 S326, when the HSS senses that the user belongs to the S-CSCF, it needs to send a registration-Termination-Request (RTR) message to the S-CSCF2.

 S328, after receiving the RTR request message, the S-CSCF2 deletes the local user data and deletes the call that the user has established;

 S330, S-CSCF2 sends a registration termination response (RTA, Registration-Termination- Answer) message to the HSS;

 In the prior art, the foregoing process S-CSCF uses the terminal to automatically refresh the registration mechanism, and completes the S-CSCF rewind operation. However, the existing rewinding technology will result in the release of the established call and the user experience is poor. Summary of the invention

 In view of the above, the main purpose of the present invention is to provide a method, a system, and a device for a DR-reversing service call session control function entity, which can prevent a UE having a session service from being interrupted during a disaster recovery process.

In order to achieve the above object, the technical solution of the present invention is achieved as follows: A method for reversing a service call session control function entity includes: performing a process of reverting the terminal UE back to the serving call session control function entity S-CSCF without performing a rewind process on the UE that still has the call service.

 Preferably, the UE that does not have a reversal process for the UE that still has the call service is:

 The proxy call session control function entity P-CSCF inserts the call information of the UE in the forwarded registration request message when forwarding the registration request message of the received UE to the query call session control function entity I-CSCF;

 The I-CSCF determines, according to the call information of the UE, that the UE still has a call service, and does not return the UE to the restored S-CSCF.

 Preferably, the method further includes:

 When the I-CSCF determines that the UE does not have a call service, the I-CSCF returns the UE to the restored S-CSCF.

 Preferably, the call information includes information about whether there is a call;

 Alternatively, the call information includes information on whether there is a call and at least one of the following information: call number information, call type or level information.

 Preferably, the call information is carried in a known field/parameter or extension field/parameter of the registration request message; the registration request message is encapsulated in an initial session protocol SIP message manner.

 A method for reversing a service call session control function entity includes:

 After receiving the registration request message of the UE, the I-CSCF returns the UE requesting registration to the restored S-CSCF;

 After receiving the registration termination request RTR message, the switched S-CSCF determines that the UE currently has a call service, and deletes the local UE user data after the UE call is released.

A system for a disaster recovery service call session control function entity, comprising an IP multimedia subsystem IMS and a UE, the IMS includes a P-CSCF, an S-CSCF, and an I-CSCF; wherein: the IMS is down Returning to the S-CSCF process, not for UEs that still have call services. Rewind processing.

 Preferably, the P-CSCF is configured to: after receiving the registration request message sent by the UE, insert the call information of the UE in the forwarded registration request message when forwarding the registration request message to the I-CSCF;

 The I-CSCF is configured to determine, according to the call information of the UE, that the UE still has a call service, and does not return the UE to the restored S-CSCF.

 Preferably, the call information includes information about whether there is a call;

 Alternatively, the call information includes information about whether there is a call and at least one of the following information: call number information, call type or level information;

 The call information is carried in a known field/parameter or extension field/parameter of the registration request message; the registration request message is encapsulated in a SIP message manner.

 A system for disaster recovery service call session control function entity includes an IP multimedia subsystem IMS and a UE, where the IMS includes a P-CSCF, an S-CSCF, and an I-CSCF;

 The I-CSCF is configured to: after receiving the registration request message of the UE, return the UE requesting registration to the restored S-CSCF;

 The switched S-CSCF is configured to: after receiving the registration termination request RTR message, determine that the UE currently has the call service, and delete the local UE user data after the UE call is released.

 A device for reversing a service call session control function entity, comprising:

 The rewinding processing unit is configured to not perform rewind processing on the UE that still has the call service during the process of reverting the UE back to the S-CSCF.

 Preferably, the rewinding processing unit is further configured to: when receiving the registration request message of the UE that is forwarded by the P-CSCF, determine, according to the call information of the UE that is carried in the registration request message, that the UE still has a call. The service does not return the UE to the recovered S-CSCF.

Preferably, the rewinding processing unit is further configured to: when determining that the UE has no call service, return the UE to the restored S-CSCF. In the present invention, in the process of reverting the UE back to the S-CSCF, the UE that still has the call service is not reversed. Specifically, the P-CSCF forwards the registration request message of the received UE to the I-CSCF. Inserting the call information of the UE in the forwarded registration request message; the I-CSCF may determine whether the UE currently has a call service according to the call information of the UE, and return the UE to the restored S- when there is no call service. CSCF, otherwise the UE is not returned to the recovered S-CSCF. Alternatively, after receiving the registration request message of the UE, the I-CSCF returns the UE requesting registration to the restored S-CSCF; after receiving the registration termination request RTR message, the switched S-CSCF determines that the UE currently has the call service. And deleting the local UE user data after the UE call is released. The invention does not release the established call service during the UE rewinding process, realizes the reentry without call loss, and greatly improves the user experience in the rewinding process. DRAWINGS

 Figure 1 is a schematic diagram of an existing IMS network architecture;

 Figure 2 is a flow chart of the current S-CSCF disaster recovery switching;

 Figure 3 is a flowchart of the disaster recovery of the existing S-CSCF;

 4 is a flowchart of a disaster recovery reversal S-CSCF in an IP multimedia subsystem according to Embodiment 1 of the present invention; FIG. 5 is a flowchart of a disaster recovery reversal S-CSCF in an IP multimedia subsystem according to Embodiment 2 of the present invention. detailed description

The basic idea of the present invention is: in the process of reverting the UE back to the S-CSCF, the UE that still has the call service is not reversed; specifically, the P-CSCF forwards the registration request message of the received UE to In the case of the I-CSCF, the call information of the UE is inserted in the forwarded registration request message; the I-CSCF may determine whether the UE currently has a call service according to the call information of the UE, and return the UE to the recovered state when there is no call service. S-CSCF, otherwise the UE will not be returned to the recovered S-CSCF. Alternatively, after receiving the registration request message of the UE, the I-CSCF returns the UE requesting registration to the restored S-CSCF; and the switched S-CSCF receives the registration termination request RTR After the information is determined, when the UE currently has a call service, the local UE user data is deleted after the UE call is released.

 The technical solutions of the present invention are further elaborated below in conjunction with specific examples.

 4 is a flowchart of a disaster recovery reversal S-CSCF in an IP multimedia subsystem according to Embodiment 1 of the present invention. As shown in FIG. 4, in this example, a UE switches from S-CSCF1 to S-CSCF2 due to a failure of S-CSCF1. The current S-CSCF1 is restored, and the UE needs to revert back to the S-CSCF2. The disaster recovery of the example S-CSCF specifically includes the following steps:

 S402, based on the disaster recovery switching mechanism, the UE has been logged on the S-CSCF2, that is, the UE has been registered to the S-CSCF2;

 S404: The UE sends a registration request message to the P-CSCF. In this step, the registration request message is mainly used for the UE to perform the reverse update.

 S406: After receiving the registration request message, the P-CSCF searches for the I-CSCF through a DNS query or other manner, and forwards the registration request message to the I-CSCF. In the present invention, the registration request message is a SIP message, and the P-CSCF In the registration request message forwarded by the I-CSCF, the call information of the UE is carried by the known or extended SIP header field/parameter; that is, the registration request message needs to be extended correspondingly, and the call information of the UE is carried in the call. The bearer mode of the information is pre-arranged between the P-CSCF and the I-CSCF, so that the I-CSCF can smoothly parse the call information of the corresponding UE. In the present invention, the call information includes whether there is a call information; or, the call information includes Whether there is information of the call and, when the call information exists, at least one of the following information: call number information, call type or level information.

S408: When the S-CSCF1 is restored and the reversal condition is met, the I-CSCF obtains the UE call information in the registration request message, determines whether the UE has a call, and sends a registration request message to the current attribution when the call exists. On the S-CSCF2, refer to S410-S424 for the subsequent process. When there is no call, the registration request message is sent to the restored S-CSCF1. For the subsequent process, refer to the foregoing S310~S330; S410. The I-CSCF sends a user authentication request UAR message to the HSS.

 S412, the HSS returns a user authentication response UAA message to the I-CSCF, where the UAA response message includes an S-CSCF host name allocated to the UE, such as S-CSCF2;

 S414. The I-CSCF sends a registration request message to the home S-CSCF2 according to the UAA response message returned by the HSS.

 S416. The S-CSCF2 sends a user configuration request SAR message to the HSS.

 S418, the HSS returns a user configuration response SAA message to the S-CSCF2.

 S420: After receiving the SAA message, the S-CSCF2 constructs and sends a registration success response message.

200 OK.

 S422, the I-CSCF forwards the registration success response message to the P-CSCF;

 S424. The P-CSCF forwards the registration success response message to the UE.

 In this example, by adding UE call information in the registration request message forwarded to the I-CSCF, the I-CSCF directly returns to the recovered S-CSCF for the UE with no call service, and for the UE with the call service. It is still registered in the current S-CSCF; in this way, by initiating the registration request message by the UE, the UE can be returned to the restored S-CSCF without interrupting the UE's call service.

 5 is a flowchart of a disaster recovery reversal S-CSCF in an IP multimedia subsystem according to Embodiment 2 of the present invention. As shown in FIG. 5, in this example, a UE switches from S-CSCF1 to S-CSCF2 due to a failure of S-CSCF1. The current S-CSCF1 is restored, and the UE needs to revert back to the S-CSCF2. The disaster recovery of the example S-CSCF specifically includes the following steps:

 S502, based on the disaster recovery switching mechanism, the UE has been logged on the S-CSCF2, that is, the UE has been registered to the S-CSCF2;

 S504: The UE sends a registration request message to the P-CSCF. In this step, the registration request message is mainly used for the UE to perform the reverse update.

S506, when the P-CSCF receives the registration request message, the P-CSCF queries through the DNS or He finds the I-CSCF and forwards the registration request message to the I-CSCF;

 S508, when the S-CSCF1 has been restored, and the reversal condition is met, and based on the automatic or manual rewinding mechanism, the UE currently belonging to the S-CSCF2 needs to be returned to the original home S- by reselecting the S-CSCF. CSCF1;

 S510. The I-CSCF sends a user authentication request UAR message to the HSS, and the HSS is required to return the S-CSCF capability set information.

 S512. The HSS returns a user authentication response UAA message to the I-CSCF, where the UAA response message includes S-CSCF capability information allocated to the UE.

 S514, the I-CSCF selects an appropriate S-CSCF host according to the UAA response message returned by the HSS, and sends a registration request message to the selected original home S-CSCF1;

 S516. The S-CSCF1 sends a user configuration request SAR message to the HSS.

 S518, the HSS returns a user configuration response SAA message to the S-CSCF1, where the SAA message carries the UE user subscription data;

 S520, after receiving the SAA message, the S-CSCF1 saves the UE user data, constructs and sends a registration success response message 200OK;

 S522. The I-CSCF forwards the registration success response message to the P-CSCF.

 S524. The P-CSCF forwards the registration success response message to the UE.

 S526, when the HSS senses that the S-CSCF to which the UE belongs changes, sending a registration termination request RTR message to the S-CSCF2;

 S528, after receiving the RTR message, the S-CSCF2 checks whether there is a call service of the UE locally. If there is a call service, the local UE user data is deleted after waiting for the call to be released normally. If there is no call service, the local service is deleted immediately. UE user data;

 S530. The S-CSCF2 sends a registration termination response RTA message to the HSS.

In this example, for a newly registered UE, it is returned to the recovered S-CSCF, and after receiving the RTR message, the UE user data still having the call service is not deleted, but After the call service ends, the UE user data is deleted, so that the reverse protection of the UE with the call service is realized, and the call service is not interrupted.

 By adopting the method of the invention, the S-CSCF without call loss is realized, and the user experience is improved. In the present invention, the P-CSCF can also be replaced by AGCF.

 The system of the disaster recovery service call session control function entity of the present invention includes an IMS and a UE, and the IMS includes network elements such as a P-CSCF, an S-CSCF, and an I-CSCF;

 During the process of reverting the UE back to the S-CSCF, the IMS does not perform reversal processing on the UE that still has the call service.

 Specifically, the P-CSCF is configured to: after receiving the registration request message sent by the UE, insert the call information of the UE in the forwarded registration request message when forwarding the registration request message to the I-CSCF;

 The I-CSCF is configured to determine, according to the call information of the UE, that the UE still has a call service, and does not return the UE to the restored S-CSCF. When the I-CSCF determines that the UE does not have a call service, the I-CSCF returns the UE to the restored S-CSCF.

 The call information includes information about whether there is a call;

 Alternatively, the call information includes information about whether there is a call and at least one of the following information: call number information, call type or level information;

 The above call information is carried in a known field/parameter or extension field/parameter of the registration request message; the registration request message is encapsulated in a SIP message manner.

 Alternatively, the system of the disaster recovery service call session control function entity of the present invention includes an IP Multimedia Subsystem IMS and a UE, and the IMS includes a P-CSCF, an S-CSCF, and an I-CSCF;

 The I-CSCF is configured to: after receiving the registration request message of the UE, return the UE requesting registration to the restored S-CSCF;

The switched S-CSCF is used to determine the UE when receiving the registration termination request RTR message. When there is a call service before, the local UE user data is deleted after the UE call is released. It should be understood by those skilled in the art that the system of the disaster recovery service call session control function entity of the present invention is implemented by improving the function of the related network element based on the existing IMS, and the existing network structure is not changed; The invention only describes in detail the functions changed by the network element. The architecture of the system for the disaster recovery service call session control function entity of the present invention can be understood by referring to the structure of the existing IMS.

 The invention also describes a device for a disaster recovery service call session control function entity, which comprises:

 The rewinding processing unit is configured to not perform rewind processing on the UE that still has the call service during the process of reverting the UE back to the S-CSCF.

 The rewinding processing unit is further configured to: when receiving the registration request message of the UE that is forwarded by the P-CSCF, determine, according to the call information of the UE that is carried in the registration request message, that the UE still has a call service. , the UE is not returned to the recovered S-CSCF.

 The rewinding processing unit is further configured to: when determining that the UE has no call service, return the UE to the restored S-CSCF.

 It should be understood by those skilled in the art that the implementation functions of the processing units in the apparatus for reversing the service call session control function entity can be understood by referring to the related description of the method for the DRD service call session control function entity. Those skilled in the art should understand that the functions of the above various units may be implemented by a program running on a processor, or by a specific logic circuit.

 The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

 Industrial applicability

The present invention does not perform rewind processing on a UE that still has a call service during the process of reverting the UE back to the S-CSCF, so that the established call service is not released during the UE rewind process. The reversal of no call loss greatly improved the user's physical insurance during the reversal process.

Claims

A method for reversing a service call session control function entity, the method comprising: in a process of reverting a terminal UE back to a serving call session control function entity S-CSCF, not for a UE that still has a call service Back to processing.  2. The method according to claim 1, wherein the UE that has a call service does not perform a rewind process, which is:  The proxy call session control function entity P-CSCF inserts the call information of the UE in the forwarded registration request message when forwarding the registration request message of the received UE to the query call session control function entity I-CSCF;  The I-CSCF determines, according to the call information of the UE, that the UE still has a call service, and does not return the UE to the restored S-CSCF.  3. The method according to claim 2, wherein the method further comprises:  When the I-CSCF determines that the UE does not have a call service, the I-CSCF returns the UE to the restored S-CSCF.  The method according to claim 2 or 3, wherein the call information includes information on whether a call exists;  Alternatively, the call information includes information on whether there is a call and at least one of the following information: call number information, call type or level information.  5. The method according to claim 4, wherein the call information is carried in a known field/parameter or extension field/parameter of the registration request message; the registration request message is encapsulated in an initial session protocol SIP message manner.  A method for reversing a service call session control function entity, the method comprising: after receiving the registration request message of the UE, the I-CSCF returns the UE requesting registration to the restored S-CSCF; After receiving the registration termination request RTR message, the switched S-CSCF determines that the UE currently has When the service is called, the local UE user data is deleted after the UE call is released.  7. A system for disaster recovery service call session control function entity, comprising an IP multimedia subsystem IMS and a UE, wherein the IMS includes a P-CSCF, an S-CSCF, and an I-CSCF; wherein: the IMS is The UE reverts back to the S-CSCF process, and does not perform rewind processing for the UE that still has the call service.  8. The system of claim 7 wherein:  The P-CSCF is configured to: after receiving the registration request message sent by the UE, when forwarding the registration request message to the I-CSCF, insert the call message of the UE into the I-CSCF in the forwarded registration request message. And determining, according to the call information of the UE, that the UE still has a call service, and does not return the UE to the restored S-CSCF.  9. The system according to claim 8, wherein the call information includes information on whether there is a call;  Alternatively, the call information includes information about whether there is a call and at least one of the following information: call number information, call type or level information;  The call information is carried in a known field/parameter or extension field/parameter of the registration request message; the registration request message is encapsulated in a SIP message manner.  10. A system for disaster recovery service call session control function entity, comprising an IP multimedia subsystem IMS and a UE, wherein the IMS comprises a P-CSCF, an S-CSCF, and an I-CSCF; wherein: The I-CSCF is configured to: after receiving the registration request message of the UE, return the UE requesting registration to the restored S-CSCF;  The switched S-CSCF is configured to: after receiving the registration termination request RTR message, determine that the UE currently has the call service, and delete the local UE user data after the UE call is released. 11. A device for reversing a service call session control function entity, comprising: a rewind processing unit, configured to have a call industry during the process of reverting the UE back to the S-CSCF The UE does not perform the rewind process.  The device according to claim 11, wherein the rewinding processing unit is further configured to: according to the UE that is carried in the registration request message, when receiving a registration request message of the UE forwarded by the P-CSCF The call information determines that the UE still has a call service and does not return the UE to the recovered S-CSCF.  The apparatus according to claim 12, wherein the rewinding processing unit is further configured to: when determining that the UE has no call service, return the UE to the restored S-CSCF.