Rapporteur: Mr. Jesske, Roland See also:
This TS describes the interworking between the TISPAN IMS and an external IP network including other IMS networks for IP multimedia service support.
This TS addresses the areas of control and user plane interworking through the network functions, which include the IBCF and I-BGF. For the specification of control plane interworking, the interworking between IMS SIP and an external SIP profile are detailed in terms of the procedures required for the support of both IMS originated and terminated SIP sessions.
In particular, this TS describes the protocol mappings for support of communications between networks using different IP versions or between networks with NATs operating at their border.