Research Of Centralized Video Conference System Based On IP Network

Compared with traditional conference, the video conference, as the means of modern communication platform and information exchanging, makes it possible for people in different places attend the same conference at the same time. On the one hand, video conference equals traditional conference quite well in terms of its effect. On the other hand, it enjoys many advantages over traditional conference in such aspects as advanced technology, powerful function and non-geographical limits. All these make people work more efficiently, more quickly and more economically. From the above, it is not hard for us to say that it is absolutely possible to replace traditional conference with video conference.At the beginning, appearance, history and IP direction of video conference system are introduced, and then this paper discusses the technologies concerning video conference in great detail and depth, especially the H.323 protocol and the structure of H.323 video conference system. Based on this, the author proposes the frame of the design. Besides, for the high demands of real-time of multi-point video conference, this part also gives a brief introduction of the real-time transportation protocol RTP and the real-time transportation control protocol RTCP. More often than not, video conference, in practical use, has several choices in control manner and topology structure. After analyzing several common conference models nowadays, this paper chooses the centralized multi-point one as the main research target. It pays special attention to the ways of implementation in different situations. It points out the strategy of cascade GK and MCU to treat with the excessive number of customers and singles out the possible problems. In this paper, video conference system is divided into client and server to be modally designed according to C/S model and the function of either is analyzed in great detail. For MCU is the centre in the H.323 centralized video conference system, it will save network bandwidth and improve transportation efficiency to apply multicast technology to the system. So, this paper also analyzes and discusses the technology, emphasizing the ways of realizing the application of multicast technology to the communication of multi-point video conference. Nowadays, though most networks allow their clients to make requirements to QoS, they do not assure them in the most cases. Thus, this paper includes the essential issues on how to assure the service quality of video conference. The management and control of video conference is the core of multi-point conference system. Based on the previous parts, management strategy and control procedure of video conference are described in great detail. Lastly, the author makes a summary of all he did and points out his own ideas.