Digital cellular telecommunications system (Phase 2+); Universal Mobile Telecommunications System (UMTS); LTE; TISPAN; PSTN/ISDN simulation services; Protocol specification Closed User Group (CUG) (V8.2.0; 3GPP TS 24.454 version 8.2.0 Release 8; Includes
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. Within the Next Generation Network (NGN) the stage 3 description is specified using the IP Multimedia Communication Control Protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP).