| With the development of the Internet and the expansion of the network's scale, the Multimedia Communication system meets a new developing chance and it has had an initial development. Network conference, as one of its promising application, is concerned widely in the industry. The multimedia conference protocol for the network conference mainly include: H.323 and SIP. Currently, most of the network conference is based on the H.323 Protocols. Although its research and development is matured, it still has disadvantage like low resource utilization, high design complexity and difficulty to expend. However, SIP with the advantage of simplicity, flexibility, opening and good expand, when it come out, it got the industry's concern and support. But SIP itself doesn't support the conference description protocol and it doesn't supply the function of conference control, it doesn't do well in the centralized management of multipoint control conference.H.323 and SIP only have relative advanced and suitable; no one can completely substitute for opposite party. In next period of time, H.323 and SIP protocols will work in network conference together. Then, the exchange and connect between network based on them become an urgently problem waiting for us to be solved.This paper first research the development and present state of network conference, on analyzing communication protocol stack based on H.323 and SIP protocol, system structure, realization and their existing question. It proposed a centralized conferencing protocol which compatible with H.323 and SIP, and study the integer framework, protocol stack, topology structure, packet format of centralized conferencing protocol which compatible with H.323 and the SIP. The design of conference object is kernel in this paper. At last, H.323 and SIP compatible centralized protocol has been implemented in OPNET software environment. |
