CN101064940A

CN101064940A - Method for realizing call

Info

Publication number: CN101064940A
Application number: CNA2006100781957A
Authority: CN
Inventors: 段朋勃; 朱奋勤
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2006-04-28
Filing date: 2006-04-28
Publication date: 2007-10-31

Abstract

The invention discloses a method to realize calling, the method includes: the called network receives the calling messages, the calling message which takes the general route user agent uniform resource identification (GRUU) or public user label (IMPU) makes a call. The method processes the user call according to ability information of user terminal, and it realizes the calling method which supports GRUU, distinguishes the calling supported GRUU mode, and improves the communication of system.

Description

A kind of method of calling out of realizing

Technical field

The present invention relates to internet protocol multimedia subsystem (IMS) technology, refer to a kind of method that in IMS, realizes calling especially.

Background technology

In 3-G (Generation Three mobile communication system), the notion based on the multimedia communication of IP technology is proposed, support that the multimedia communication based on IMS is a key technology of 3G (Third Generation) Moblie.

In the system of IMS, support a plurality of user terminals (UE) registration identical public subscriber identification (IMPU), under the situation of the shared IMPU of a plurality of UE, when IMS is sent to IMPU with message, need the UE that each shares this IMPU will be distributed to after the single message copy.The address of IMS and route only depend on IMPU, share at a plurality of UE under the situation of an IMPU, distinguish specific UE if desired, message is dealt into some among a plurality of UE that share this IMPU, in order from a plurality of UE, to distinguish out this particular UE, IETF has proposed to adopt general routable user proxy URI (GRUU, Global Routable User Agent URI) to distinguish this particular UE at present, and GRUU is by a kind of sign of network side for distributing for each UE.

At present in the method for calling among the IMS, service conversation among the IMS is called out control (S-CSCF) entity when transmitting called message related to calls, always unconditionally with the information of carrying in the request unified resource of carrying in the message related to calls sign (Request-URI) such as called IMPU, copy among the P-Called-Party-ID, the UE that receives message related to calls distinguishes calling party's information by P-Called-Party-ID.Wherein, P-Called-Party-ID is a stature field of session initiation protocol (SIP), and the carrying caller sends to the called party information in the called message related to calls, can be called called ID.

Do not have in the existing call scheme to describe and whether consider and how to distinguish the mode of supporting GRUU with the process user terminal, if also continue to use the existing call method, for calling out called is the GRUU mode, but terminal called self is not supported the situation of GRUU, can cause the unusual problem of called processing, be not familiar with GRUU such as called, when therefore being GRUU, can't determine that interrelated logic handles for the information of carrying among the P-Called-Party-ID.Influence the inter-communicating problem of system.In addition, not clear and definite UE adopts GRUU rather than adopts IMPU under which kind of situation, when user itself has privacy to require, can reveal some privacy informations of user.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of method of calling out of realizing, can distinguish the mode of supporting GRUU with the process user terminal, improves the interoperability of system.

For achieving the above object, technical scheme of the present invention specifically is achieved in that

A kind of method of calling out of realizing, in internet protocol multimedia subsystem IMS, this method comprises:

A. after the called network side joint was received message related to calls, according to acquired ability information of user terminal, the general routable user proxy unified resource identification GRUU or the public subscriber identification IMPU that carry the called subscriber in message related to calls called out.

Before the steps A, this method also comprises: described network side obtains ability information of user terminal by user registration course.

Described ability information of user terminal is first ability information of user terminal whether identifying subscriber terminal supports GRUU.

The method of described acquisition ability information of user terminal is:

After service conversation CCF S-CSCF entity in the described network side receives login request message, judge and whether carry the description of supporting GRUU in this login request message, if carry, then described this registered user's of S-CSCF entity record first ability information of user terminal is for supporting GRUU; Otherwise first ability information of user terminal that writes down this registered user is not for supporting GRUU.

Described ability information of user terminal is distributed to second the ability information of user terminal whether GRUU of user terminal is supported by user terminal for sign.

The method of described acquisition ability information of user terminal is:

Described service conversation CCF S-CSCF entity is judged the example that whether carries this registered user in the described login request message,

If carry this registered user's example, and carry the description of supporting GRUU in the described login request message, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and supported by described user terminal, and in the successful registration reply message that returns, carry the GRUU of this distribution for the GRUU of this distribution;

If carry this registered user's example, but do not carry the description of supporting GRUU in the described login request message, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and do not supported, in the successful registration reply message that returns, do not carry the GRUU of this distribution by described user terminal for the GRUU of this distribution;

If do not carry registered user's example, return success registration reply message.

Steps A specifically comprises:

A1. S-CSCF in the described called network judges whether what receive that request unified resource sign Request-URI field information shows in the request message is GRUU, if that show is GRUU, then enters steps A 2; Otherwise, enter steps A 5;

A2. described S-CSCF judges whether self stores described GRUU, if store, then enters steps A 3; Otherwise, enter steps A 4;

Whether first ability information of user terminal of A3. judging described called subscriber shows is supported GRUU, if support, described GRUU is carried in the request message carrying caller sends in the called message related to calls and call out process ends; If do not support, then from described GRUU, extract IMPU, and be carried in the request message carrying caller and send in the called message related to calls and call out process ends;

A4. judge whether network allows the GRUU unregistered service,, then carry out the GRUU unregistered service, jump out this flow process if allow; If do not allow, then refuse current request, jump out this flow process;

A5. described S-CSCF is carried at the information of Request-URI in the described message related to calls in the CSI called subscriber identification P-Called-Party-ID field that carrying caller in the request message sends to the called party information in the called message related to calls and calls out.

Steps A specifically comprises:

A1. S-CSCF in the described called network judges whether what receive that request unified resource sign Request-URI field information shows in the request message is GRUU, if that show is GRUU, then enters step a2; Otherwise, enter step a5;

A2. described S-CSCF judges whether self stores described GRUU, if store, then enters step a3; Otherwise, enter step a4;

Whether second ability information of user terminal of a3. judging described called subscriber shows that described GRUU is supported by user terminal, if support, described GRUU is carried in the request message carrying caller sends in the called message related to calls and call out process ends; If do not support, then from described GRUU, extract IMP U, and be carried in the request message carrying caller and send in the called message related to calls and call out process ends;

Described GRUU is carried in the P-Called-Party-ID field of described message related to calls; The described IMPU that extracts from described GRUU is carried in the P-Called-Party-ID field of described message related to calls.

Among steps A 2 or the step a2, described judging stores after the GRUU, enters before steps A 3 or the step a3, and this method also comprises: described S-CSCF extracts IMPU from GRUU, carries out initial filter criteria iFC service logic control and treatment.

Among steps A 4 or the step a4, described judging allows after the GRUU unregistered service, carries out before the GRUU unregistered service, and this method also comprises:

Whether described GRUU has the GRUU unregistered service, if having, then carries out the GRUU unregistered service; If do not have, then refuse current request, and return Reason For Denial.

In the steps A 3, judging described called user terminal does not support after the GRUU, if it is the GRUU of this storage that the GRUU that the promising described called subscriber of storage distributes among the described S-CSCF, then described S-CSCF will respond the IP address substitution that contact contact field is carried in the message of described request message.

Among the step a3, judge described GRUU not by after the user terminal support, if it is the GRUU of this storage that the GRUU that the promising described called subscriber of storage distributes among the described S-CSCF, then described S-CSCF will respond the IP address substitution that contact contact field is carried in the message of described request message.

This method also comprises:

I. in the described calling, described called network side act on behalf of the called party information of carrying in the request message that conference call controlled function P-CSCF entity stores receives, and this request message is transmitted to described called user terminal;

II. described called user terminal sends response message to P-CSCF, described P-CSCF judges whether the called party information of self having stored is GRUU, if then extract IMPU from this GRUU, and the IMPU that extracts is carried in the response message, send and acknowledge message to described S-CSCF; If not then the called party information that self has been stored is carried at and sends to described S-CSCF in the response message;

Perhaps, the called party information that described P-CSCF has directly stored self is carried in the response message, and this response message is sent to S-CSCF;

III. described S-CSCF judges whether the information in the response message that receives is GRUU, if then extract IMPU from this GRUU, and the IMPU that extracts is carried at is sent to the caller network in the response message; If not, will receive response message and be forwarded to the caller network;

Perhaps, described S-CSCF directly will receive response message and be forwarded to the caller network.

Described called party information is carried in the P-Called-Party-ID field of described request message; Described being carried in the response message to be carried in the P-Asserted-Identity field of described response message.

When calling subscriber self had GRUU, before the described steps A, this method also comprised:

If when the calling subscriber had privacy to require, then call subscriber terminal carried self IP address in the contact of message related to calls field; Otherwise call subscriber terminal carries GRUU in the contact of message related to calls field.

Before the described steps A, this method also comprises:

S-CSCF in the caller network receives message related to calls, carries GRUU in this message related to calls and carries the privacy requirement if judge, and then this S-CSCF replaces with GRUU calling subscriber's IP address.

As seen from the above technical solution, the present invention is after network side receives message related to calls, and according to acquired ability information of user terminal, the GRUU or the IMPU that carry called user terminal in message related to calls call out.The inventive method is at the ability information of user terminal of UE, and the S-CSCF in network side handles accordingly to the calling of UE, has realized supporting the method for calling of the mode of GRUU, has distinguished terminal and whether has supported GRUU, has improved the interoperability of system.Wherein, ability information of user terminal can refer to be used for first ability information of user terminal whether identifying subscriber terminal supports GRUU, perhaps is used for the marked network side and is second ability information of user terminal whether GRUU that user terminal distributes is supported by current caller party terminal.

In addition; the inventive method further supports the situation of GRUU to carry out relevant treatment to call subscriber terminal; when the calling subscriber has privacy to require; and when carrying GRUU in the message related to calls; network side or end side replace with the IP address of this calling UE with the GRUU that carries, and have protected some privacy informations of user.

To sum up, the inventive method is to the replenishing of existing call flow process, and has improved the interoperability of system.

Description of drawings

Fig. 1 is the flow chart of user's registration of the present invention;

Fig. 2 is that the present invention realizes the flow chart called out.

Embodiment

Core concept of the present invention is: after the called network side joint was received message related to calls, according to acquired ability information of user terminal, the GRUU or the IMPU that carry the called subscriber in message related to calls called out.

For making purpose of the present invention, technical scheme and advantage clearer, below with reference to the accompanying drawing preferred embodiment that develops simultaneously, the present invention is described in more detail.

, carry out before the call treatment according to ability information of user terminal at network side, network side can obtain the ability information of user terminal whether user terminal supports GRUU by user registration course.Fig. 1 is the flow chart of user's registration of the present invention, mainly may further comprise the steps:

Step 100～step 105:UE is by acting on behalf of conference call controlled function (P-CSCF) entity, and inquiry conference call controlled function (I-CSCF) entity of home network is initiated login request message under self; I-CSCF initiates user registration state query requests (UAR) to home subscriber server (HSS), title or ability level information according to the S-CSCF that carries in the user-authorization-answer (UAA) from HSS, select this service conversation to call out control (S-CSCF) entity, and login request message is transmitted to this S-CSCF.

The specific implementation of this step can be stipulated referring to related protocol, no longer describes in detail here.

Step 106～step 108:S-CSCF authenticates UE according to login request message, and after authentication was passed through, S-CSCF was to HSS send server request for allocation (SAR), and HSS returns server-assignment response (SAA) to S-CSCF after receiving SAR.

Step 109～step 110:S-CSCF is according to the login request message that receives, determine whether UE supports GRUU, whether be that UE distributes GRUU, and return success registration reply message 200OK to UE according to the example decision of whether carrying UE in the registration message simultaneously through I-CSCF and P-CSCF.

Specific implementation comprises:

S-CSCF judges whether carry description such as the Supported:gruu that supports GRUU in the login request message, if have, and carry example such as the sip.instance of UE in describing simultaneously, it also is instance number, then S-CSCF is the UE distribution and stores a GRUU, and first ability information of user terminal that writes down this UE is for supporting GRUU, and second ability information of user terminal is supported by described user terminal for the GRUU of this distribution, carry the GRUU that distributes to UE in the 200OK message of returning;

If only carry the UE example in the login request message, do not carry the description of supporting GRUU, then S-CSCF can have following two kinds of processing methods:

Method one: S-CSCF is a UE GRUU of distribution and is stored among the S-CSCF, first ability information of user terminal that writes down this user is not for supporting GRUU, second ability information of user terminal is not supported by described user terminal for the GRUU of this distribution, in the 200OK message of returning, do not carry the GRUU that distributes to UE, consistent in this 200OK message and the existing register flow path.The method of other network element by subscribing to can obtain this GRUU, simultaneously also can be with this GRUU as called identification.

Method two: S-CSCF is not that UE distributes GRUU, and first ability information of user terminal that writes down this user is for supporting GRUU, consistent in the 200OK message of returning and the existing register flow path.

If in the login request message, neither carry the description of supporting GRUU, do not carry the UE example yet, then S-CSCF first ability information of user terminal that writes down this UE is for supporting GRUU, consistent in the 200OK message of returning and the existing register flow path.

If in the login request message, carry the description of supporting GRUU, but do not carry the UE example, then S-CSCF is for UE distributes GRUU, and first ability information of user terminal that writes down this UE is support GRUU, consistent in the 200OK message of returning and the existing register flow path.

Need to prove, there is not sequencing in the judgement of in this step whether user terminal being supported the judgement of GRUU and whether carrying customer instance, and two process can independent separate processes, after receiving login request message such as the S-CSCF entity, according to whether carrying the description of supporting GRUU in this login request message, whether this registered user's of decision record first ability information of user terminal supports GRUU, if carry, then described this registered user's of S-CSCF entity record first ability information of user terminal is for supporting GRUU; Otherwise first ability information of user terminal that writes down this registered user is not for supporting GRUU.

According to the example that whether carries this registered user in the described login request message, whether decision distributes for this registered user and storage GRUU and write down second ability information of user terminal, if carry this registered user's example, and when registering, the user carries the description of supporting GRUU, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and supported by described user terminal, and in the successful registration reply message that returns, carry the GRUU of this distribution for the GRUU of this distribution; If carry this registered user's example, but when registering, the user do not carry the description of supporting GRUU, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and do not supported, in the successful registration reply message that returns, do not carry the GRUU of this distribution by described user terminal for the GRUU of this distribution; If do not carry registered user's example, return success registration reply message.

Need to prove, the present invention to the processing of user registration course with can independently carry out respectively called processing.

So far, the S-CSCF in network side has write down ability information of user terminal.S-CSCF can carry out respective handling to message related to calls according to the ability information of user terminal of UE when handling message related to calls like this, distinguishes and handle the mode of supporting GRUU of calling out, and improves the interoperability of system.

Fig. 2 is that the present invention realizes the flow chart called out, supposes that here UE is called, and the processing of caller network and existing procedure are in full accord among Fig. 2, does not therefore provide the concrete entity handles flow process of caller network, and method of calling of the present invention may further comprise the steps:

Step 200:S-CSCF receives session initiation protocol (SIP) request (REQUEST) message from the caller network.

Step 201:S-CSCF judges that the value of Request-URI field in the REQUEST message of receiving is GRUU or IMPU, and carries GRUU or IMPU in the P-Called-Party-ID of REQUEST message field.The concrete processing of this step comprises:

If the value of Request-URI field is not GRUU, then S-CSCF carries out initial filter criteria (iFC) service logic control and treatment according to existing standard; After the service logic control and treatment, S-CSCF is carried at Request-URI value copy in the CSI called subscriber identification P-Called-Party-ID field that carrying caller in the request message sends to the called party information in the called message related to calls and calls out.

If the value of Request-URI field is GRUU, so, S-CSCF judges whether self stores this GRUU, if store, then this GRUU is registered, otherwise this GRUU is unregistered;

If GRUU is unregistered, but network allows GRUU to have GRUU unregistered service such as portable terminal to be in off-mode but still can keep to receive short message service etc., judge further then whether this GRUU has the GRUU unregistered service,, carry out the GRUU unregistered service if having; If do not have, then refuse this REQUEST message, and return Reason For Denial; If network does not allow GRUU that the GRUU unregistered service is arranged, then refuse this REQUEST message, and return Reason For Denial;

If GRUU registers, then S-CSCF extracts IMPU from GRUU, carries out initial filter criteria (iFC) service logic control and treatment.IFC handles the technology as well known to those skilled in the art that belongs to, and can no longer describe in detail here with reference to related protocol.Whether allow the GRUU unregistered service about network, whether user terminal has the concrete determination methods of GRUU unregistered service and the present invention to have nothing to do, can stipulate referring to related protocol, here repeat no more, what the present invention emphasized is, when in message related to calls, carrying GRUU, and the improvement of the processing under the different call case, distinguish and handle the mode of supporting GRUU of calling out to arrive the present invention, improve the purpose of the interoperability of system.

In the business logic processing process, whether S-CSCF can also support that GRUU does respective handling at the application server among the IMS (AS), know that as S-CSCF transmitting the Request-URI value is the AS of the SIP request of GRUU when not supporting GRUU, network has three kinds of different disposal methods:

1) S-CSCF is converted to IMPU with the value of Request-URI from GRUU;

2) value at Request-URI is done particular provisions in iFC, guarantees that the AS that handles GRUU supports GRUU;

3) S-CSCF does not do special processing, transmits message according to present processing policy and gives AS, after AS receives this message, handles according to the IMPU mode that can discern from GRUU;

After the service logic control and treatment, S-CSCF handles as follows according to first ability information of user terminal of the UE that has write down in the registration process:

1. support GRUU if first ability information of user terminal of UE shows, then S-CSCF is GRUU with the value of Request-URI field, is carried in the P-Called-Party-ID field that is ready for sending to the REQUEST message of P-SCSF.

2. if showing, first ability information of user terminal of UE do not support GRUU, but the value of Request-URI is GRUU, then S-CSCF extracts IMPU from this GRUU, and the IMPU that extracts is carried in the P-Called-Party-ID field that is ready for sending to the REQUEST message of P-SCSF.

Perhaps, S-CSCF handles as follows according to second ability information of user terminal of the UE that has write down in the registration process:

Whether second ability information of user terminal of judging described called subscriber shows that described GRUU is supported by user terminal, if support, described GRUU is carried at carrying caller in the request message sends in the P-Called-Party-ID field in the called message related to calls and call out; If do not support, then from described GRUU, extract IMPU, and be carried in the P-Called-Party-ID field and call out.

REQUEST message after step 202～step 204:S-CSCF will handle through step 201 sends to P-CSCF; After P-CSCF receives REQUEST message, store the called party information that the P-Called-Party-ID field is carried in the REQUEST message, and give UE this REQUEST forwards.

After UE receives REQUEST message, the called subscriber can make different processing according to the called party information that the P-Called-Party-ID field is carried, such as, if the called party information that the P-Called-Party-ID field is carried is GRUU, UE may accept this calling, replys this calling; If the called party information that the P-Called-Party field is carried is IMPU, UE may refuse this calling etc., and concrete UE result depends on user intention or UE interior business logic fully.

Step 205～step 207:UE sends response message to P-CSCF; After P-CSCF receives response message, carry out the P-Asserted-Identity field by following mode and handle, and the response message after will handling sends to S-CSCF.

P-CSCF can directly be carried at the P-Called-Party-ID field information of having stored in the P-Asserted-Identity field; Also can make the following judgment the P-Called-Party-ID information of having stored earlier:

If the P-Called-Party-ID field information of having stored is GRUU, P-CSCF extracts IMPU from GRUU so, and IMPU is carried in the P-Asserted-Identity field; Otherwise the P-Called-Party-ID field information that directly will store is carried in the P-Asserted-Identity field.Wherein, P-Asserted-Identity is a stature field of sip message, and carrying sends the authenticating party of sip message, can be called authentication ID.

The information that step 208:S-CSCF carries according to P-Asserted-Identity field in the response message of receiving is called out after can selecting the P-Asserted-Identity field handled.The concrete processing of this step comprises: after S-CSCF receives response message,

S-CSCF judges whether the information that the P-Asserted-Identity field in the response message is carried is GRUU, if, from GRUU, extract IMPU, and after being carried at the IMPU that extracts in the P-Asserted-Identity field, sending and acknowledge message to the caller network.If not, will receive response message according to existing procedure and be forwarded to the caller network.

Perhaps, S-CSCF will receive response message according to existing procedure and be forwarded to the caller network and get final product.

From flow process shown in Figure 2 as seen, the inventive method is handled the calling of UE at network side accordingly at the ability information of user terminal of UE, has realized supporting the method for calling of the mode of GRUU.Distinguish terminal and whether supported the mode of GRUU, called for GRUU but terminal called self does not support the different UEs of GRUU to take different processing methods for calling out, improved the interoperability of system.

The inventive method further comprises: have under the GRUU situation for calling UE self, usually, require calling UE as far as possible GRUU to be carried at Contact header field, rather than the IP address is placed on Contact header field.If but when calling UE has privacy to require, need carry out following processing:

Method one:, in the contact of message related to calls field, carry self IP address rather than GRUU even UE self this moment has GRUU if when calling UE has privacy to require.

Method two: when S-CSCF received message related to calls, if carry GRUU in the message related to calls and comprise the privacy requirement, then S-CSCF replaced with this calling subscriber's IP address with the GRUU field, continues call flow again.

How the user carries privacy requires and can stipulate referring to related protocol, irrelevant with the inventive method, repeats no more here.

Method one and method two can use simultaneously, promptly all do relevant treatment in UE side and network side.Method one and method two also can use separately, promptly only in the UE side or only do relevant treatment at network side.

To the processing of calling UE, when the user has privacy to require, and when carrying GRUU in the message related to calls, network side or end side replaced with the IP address of this calling UE with the GRUU that carries, and have protected some privacy informations of user when the present invention called out.

Need to prove, the present invention to the processing of caller with can carry out simultaneously called processing, also can independently carry out.

The above is preferred embodiment of the present invention only, is not to be used to limit protection scope of the present invention, all any modifications of being made within the spirit and principles in the present invention, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. a method that realizes calling out in internet protocol multimedia subsystem IMS, is characterized in that, this method comprises:

2. method according to claim 1 is characterized in that, before the steps A, this method also comprises: described network side obtains ability information of user terminal by user registration course.

3. method according to claim 2 is characterized in that, described ability information of user terminal is first ability information of user terminal whether identifying subscriber terminal supports GRUU.

4. method according to claim 3 is characterized in that, the method for described acquisition ability information of user terminal is:

5. method according to claim 2 is characterized in that, described ability information of user terminal is distributed to second the ability information of user terminal whether GRUU of user terminal is supported by user terminal for sign.

6. method according to claim 5 is characterized in that, the method for described acquisition ability information of user terminal is:

If carry this registered user's example, and carry the description of supporting GRUU in the described login request message, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and supported by user terminal, and in the successful registration reply message that returns, carry the GRUU of this distribution for the GRUU of this distribution;

If carry this registered user's example, but do not carry the description of supporting GRUU in the described login request message, then distribute and storage GRUU for this registered user, write down described second ability information of user terminal simultaneously and do not supported, in the successful registration reply message that returns, do not carry the GRUU of this distribution by user terminal for the GRUU of this distribution;

7. method according to claim 3 is characterized in that steps A specifically comprises:

8. method according to claim 5 is characterized in that steps A specifically comprises:

Whether second ability information of user terminal of a3. judging described called subscriber shows that described GRUU is supported by user terminal, if support, described GRUU is carried in the request message carrying caller sends in the called message related to calls and call out process ends; If do not support, then from described GRUU, extract IMPU, and be carried in the request message carrying caller and send in the called message related to calls and call out process ends;

9. according to claim 7 or 8 described methods, it is characterized in that described GRUU is carried in the P-Called-Party-ID field of described message related to calls; The described IMPU that extracts from described GRUU is carried in the P-Called-Party-ID field of described message related to calls.

10. according to claim 7 or 8 described methods, it is characterized in that, among steps A 2 or the step a2, described judging stores after the GRUU, enter before steps A 3 or the step a3, this method also comprises: described S-CSCF extracts IMPU from GRUU, carries out initial filter criteria iFC service logic control and treatment.

11., it is characterized in that among steps A 4 or the step a4, described judging allows after the GRUU unregistered service according to claim 7 or 8 described methods, to carry out before the GRUU unregistered service, this method also comprises:

12. method according to claim 7, it is characterized in that, in the steps A 3, judging described called user terminal does not support after the GRUU, if it is the GRUU of this storage that the GRUU that the promising described called subscriber of storage distributes among the described S-CSCF, then described S-CSCF will respond the IP address substitution that contact contact field is carried in the message of described request message.

13. method according to claim 8, it is characterized in that, among the step a3, judge described GRUU not by after the user terminal support, if it is the GRUU of this storage that the GRUU that the promising described called subscriber of storage distributes among the described S-CSCF, then described S-CSCF will respond the IP address substitution that contact contact field is carried in the message of described request message.

14., it is characterized in that this method also comprises according to claim 1,7 or 8 described methods:

15. method according to claim 14 is characterized in that, described called party information is carried in the P-Called-Party-ID field of described request message; Described being carried in the response message to be carried in the P-Asserted-Identity field of described response message.

16. method according to claim 1 is characterized in that, when calling subscriber self had GRUU, before the described steps A, this method also comprised:

17. method according to claim 1 is characterized in that, before the described steps A, this method also comprises: