Research On Key Fields Of Multi-Media Conferencing System Based On H.323 Protocols

As the information era proceeds,highly developed digital image processing technique and communication technique make multimedia communication possible,and it is now on the way of progress. multi-media conference have received more attention as an example of multimedia.All kinds of industries try to take use of the multi-media conference as one of the newly communication tools. electric power industry is the important department of our country,so it also need the multi-media conference to increase it's efficiency.In this paper we first describe the construction and characteristic of the multi-media conference system and analyze the theory of protocol with ITU-T H.323 Recommendation which inculde video and audio codec standard, communication control protocol H.245,call signalling protocol H.225,as well as procedures within these protocols define how these components communicate.Based on the these,we discuss the structure and the protocol stack T.120 of the data conference which as the important sub-system of the multimedia conference system.Here we suggest a method to predigest the T.120 protocol stack..That is we use the Socket model to complete the transmission functions .At last ,as we analyse before ,we give the method to design and implement of the data conference. This system include Whiteboard system,File transmission system and Documentation share system.we use the modularization method to implement the system based on the transmission interface that the Socket provide.Such system can be widely used in the fields such as business conference,distance education ,power system etc. And it is of good practical value.