Call forwarding in an ip multimedia subsystem (ims)

The invention claims a press Session the starting communication Protocol in IP multimedia subsystems method, wherein the shell is received by calling forwarding operation of Session starting Protocol application server processing. The method comprises the reprecipitation in/of controlling function of a INVITE a services call user equipment INVITE R-URI is marked; and services call/of controlling function of/, and controlling function and INCLUDING initial dialog identifier is the services call to form the INVITE message routing masthead, and/in the control function and initial dialog identifier of the services call and mapping relationship between R-URI. The INVTE given is connected to a forwarding using the server, and user equipment R-URI URI is of substrates forwarding the support part at for calling the form of forwarding. Gain forwarding display in INVITE masthead, and heating services call INVITE the switching-on/of controlling function. At the services call/in the control function, respectively located existence of forwarding display, initial dialog identifier of comprises a response to return's INVITE in a initial R-URI. According to R-URI initial identification call barring and IFC.