1 Scope

24.4543GPPProtocol specification Closed User Group (CUG)PSTN/ISDN simulation servicesRelease 8TISPANTS

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).