Patent ID: 9077721
Filing Date: 2015-07-07
Classification: H04L

Abstract:
1. A method in a Session Initiation Protocol Application Server (SIP-AS) for registering a user to an IP Multimedia Subsystem (IMS) network, the method comprising: requesting by the SIP-AS, required Serving Call/Session Control Function (S-CSCF) capabilities from a Home Subscriber Server (HSS); receiving the required S-CSCF capabilities by the SIP-AS from the HSS over an Sh interface; performing S-CSCF selection by the SIP-AS according to predefined criteria, thereby eliminating the need for a separate Interrogating Call/Session Control Function (I-CSCF); and performing a SIP registration on the user's behalf by the SIP-AS so as to allow the SIP-AS to act as a SIP User Agent for the user, wherein the SIP-AS performs the registration over a Service Control Interface (ISC) directly with the selected S-CSCF, and wherein the registration enables the user to access user and subscription profiles defined for the user within the IMS network.