1 Scope

24.6543GPPClosed User Group (CUG) using IP Multimedia (IM) Core Network (CN) subsystem, Protocol SpecificationRelease 16TS

The present document specifies the stage three Protocol Description of the Closed User Group (CUG) service, based on stage one and two of the ISDN Communication diversion supplementary services. It provides the protocol details in the IP Multimedia (IM) Core Network (CN) subsystem based on the Session Initiation Protocol (SIP) and the Session Description Protocol (SDP).

The present document is applicable to User Equipment (UE) and Application Servers (AS) which are intended to support the CUG supplementary service.