Research On Design And Implementation Of H.323 Videotelephone Communication Software Protocols

The trend that China's Multimedia Networks is developing to wide band and IP centered brings the development at full speed of the communication business of the multimedia. At present, there are two standards in the world which network meeting and net telephone software adopt for: ITU's H.323 and IETF's SIP. Compared with H.323, SIP is simple, it's expanding is better. However, H.323 appears relatively early, is riper, and there are much business application complies with it. So, H.323 will coexist with SIP in long time. This paper gives an overview of the H.323 set of standasds, and then describes the organization and principles of the multimedia conferencing and videotelephone systems on the internet. Then describes the communication protocol stack of H.323 Recommendation: H.245 and H.225. Base on researching of H.323 Recommendation, we give a implement of H.323 communication protocol stock which complies with H.323 Recommendation. In the program, designs our message queue to reduce data copying and improve controllability; and designs our memory management to reduce the negative effect of memory segment. In the consequent chapter, we give the result of experimentation using protocol testing tools, communicates with Microsoft Netmeeting and other H.323 terminals using our terminal. The result of the experimentation revealed that our terminal complies with H.323 Recommendation. In the end, we put forward the future striving direction according to the present state.