This TS 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 TS 23.231.
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 TS 23.231 and TS 23.153
This TS is valid for a 3rd generation PLMN (UMTS) complying with Release 8 and later.