The Research On The Key Technology And The Application Of The VoIP-based Campus Network Videophone Conference System

With the rapid development and popularization of the computer network and the technology of digital communication, internet which bases on TCP/IP has more and more influence on people's life, meanwhile stimulates the fast development of all kinds of applied technology based on IP. Herein VoIP technology is a typical example.VoIP (Voice over Internet Protocol) is not only the narrow concept of IP telephone, but also an integrative application platform which can supply real-time voice/video multimedia communication operation. Because the VoIP technology can realize multimedia transferring like real-time voice over IP network, it has many advantages such as narrow bandwidth occupied, high efficiencies of resource utilized, and low cost. With these characters, VoIP has been widely applied all over the world.This thesis firstly introduces the prospect and basic principle of VoIP and researches the related technology of VoIP based on discussing the current status and development trend of IP telephone. And then it labors the status in quo of the campus network and telephone network of Zhangjiajie Vocational College of Aeronautical Engineering. As a typical intranet, campus network has the problems of singleness of application,low efficiencies of resource utilized,and waste of bandwidth. How to realize more applications based on campus network and improve the efficiency are the most desiderate problems. Aim at this problem, we proposed a solution of campus network videophone conference system based on VoIP. Based on this work , the program of voice part of PC-to-PC videophone terminal based on campus network is designed and implemented with the modular design method by researching hardware equipment ,software system, network communication and network management, which includes some key technologies on audio/video coding and decoding, network management and real-time transportation. The result of the experiment confirmed that the function which making use of the existing available campus network to realize IP telephone is feasible,which also can save bandwidth and telephone price and may excavate the latent energy of the existing resource sufficiently together. At last, this thesis prospects the future of the VoIP technology and the further work.