Hi, We are new to this list and need some clarification related to H.245 call signaling on TCP/IP channel.. Considering a separate H.245 connection is required per call implies that each connection shall have a separate port to associate H.245 messages with its call. This requires the endpoint application to maintain an association between ports and the call_id/call_ref value. Isn't it useful to have some correlation_id or call_ref (or call_id) value in each of the H.245 messages to associate H.245 messages with call instances at the endpoints (gateways). Regards, Ravi Kiran Sunil Mahajan