IP Multimedia Subsystem (IMS); Sc Interface based on the Diameter protocol;
The present document describes the diameter-based Sc interface between Data Channel Signalling Function (DCSF) and Home Subscriber Server (HSS) and specifies:
1. The interactions between the Data Channel Signalling Function (DCSF) and Home Subscriber Server (HSS) at the Sc reference point, including the procedures and signalling flows.
2. The protocol specifications and implementations, including the diameter application, commands and message contents at the Sc reference point.
The IP Multimedia Subsystem (IMS) supporting DC architecture and procedures are specified in 3GPP TS 23.228 [2].
Whenever it is possible this document specifies the requirements for this protocol by reference to specifications produced by the IETF within the scope of Diameter base protocol as specified in IETF RFC 6733 [3]. Where this is not possible, extensions to the Diameter base protocol as specified in IETF RFC 6733 [3] are defined within this document.