Application of SIP-I Protocols to Circuit Switched (CS) core network architecture; Stage 3
The present document describes the protocols to be used when SIP-I is optionally used as call control protocol in a 3GPP CS core network on Nc interface, see 3GPP TS 23.231 [1]. The SIP-I protocol operates between (G)MSC servers. The SIP-I architecture consists of a number of protocols. The following types of protocols are described: call control protocol, resource control protocols and user plane protocol for this architecture. The architecture complies with the requirements imposed by 3GPP TS 23.231 [1] and TS 23.153 [2].
Interworking of SIP-I on Nc to external networks is described by TS 29.235 [3].
The present document is valid for a 3rd generation PLMN (UMTS) complying with Release 8 and later.