Exchange protocol for combinational multimedia services

摘要

A method of transporting image or video information between end user terminals via a packet switched network whilst a circuit switched connection is established between the end users includes establishing a circuit switched connection between a plurality of end user terminals for carrying voice traffic. The method also includes using the Message Session Relay Protocol (MSRP) to encapsulate image or video information transmitted between end user terminals via a packet switched network, where MSRP related traffic is routed between said end user terminals via one or more MSRP enabled nodes. Additionally, the method includes installing service policies into the or at least one MSRP node from a session initiation protocol (SIP) application server (AS) located in the control-plane of an IMS network and checking multimedia service requests against the installed policies to control end user terminal access to certain packet based services.