Patent ID: 8782208

Claim:
A method for use in an IP Multimedia Subsystem, IMS, the method comprising: receiving a Session Initiation Protocol, SIP, message, the SIP message being associated with a user; forwarding the SIP message to a first Serving Call/Session Control Function, S-CSCF, of the IMS assigned to provide services to the user; when it is determined that forwarding the SIP message to the first S-CSCF has failed, sending a request message to a Home Subscriber Server, HSS, of the IMS to request capabilities information for selecting a second S-CSCF, the request message also providing status information relating to a status of the first S-CSCF; and on receipt of the capabilities information from the HSS, selecting the second S-CSCF to provide services to the user based on the received capabilities information, wherein the method is performed by an Interrogating Call/Session Control Function, I-CSCF, of the IMS.