24.6543GPPClosed User Group (CUG) using IP Multimedia (IM) Core Network (CN) subsystem, Protocol SpecificationRelease 16TS
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
– References are either specific (identified by date of publication, edition number, version number, etc.) or non‑specific.
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– For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
 3GPP TS 22.173: "IP Multimedia Core Network Subsystem (IMS) Multimedia Telephony Service and supplementary services, stage 1".
 3GPP TS 24.229: "Internet Protocol (IP) multimedia call control protocol based on Session Initiation Protocol (SIP) and Session Description Protocol (SDP); Stage 3".
 3GPP TS 24.238: "Session Initiation Protocol (SIP) based user configuration; stage 3".
 3GPP TS 24.623: "Extensible Markup Language (XML) Configuration Access Protocol (XCAP) over the Ut interface for Manipulating Supplementary Services".
 IETF RFC 5621: "Message Body Handling in the Session Initiation Protocol (SIP)".
 3GPP TS 24.174: "Support of Multi-Device and Multi-Identity in IMS; Stage 3".