With the explosive increase of Internet users and Internet traffics in recent years, a new class of services based on integration of the public switched telephone network (PSTN) and the IP network for VoIP is being widely used experimentally for aiming commercial use of it. For the VoIP service over the PSTN and IP networks, conversion between the SS7 signaling system and the SIP or H.323 protocols is needed. It also requires some entities like the media gateway, the media gateway controller and the signaling gateway for the service.
In this thesis work, we describe SS7 signaling and H.323 call setup procedure and propose a message mapping scenario between the SS7 call setup messages and the H.323 messages based on protocol conversion location. The proposed scenario focuses on reduction of call setup time between PSTN/IP networks. A scenario to support IN-based services in converged PSTN/IP networks is discussed, too.
The proposed scenario is verified by computer simulation. We make simple models of SS7 protocol stack and M3UA. In the simulation, we show that protocol conversion at the signaling gateway for basic call setup messages can reduce the call setup time by adopting IPSCP. In addition, we suggest an alternative scenario about conversion between SS7 signaling system and H.323 call signaling in this thesis.