Study And Design Of Video Conferencing System Based On .NET Framework

With the popularization of the Internet and the improvement of its performance, more and more enterprises, organizations and people use network to distribute information and communicate with each other. Especially the video conferencing system, which can make users free from the restriction of distance, provides users a convenient way to communicate in the form of audio/video. The video conferencing system can not only save the time and expense of the users to take part in the conference but also get rid of the potential danger of traffic accidents and infectious diseases. It is becoming a hotspot of the computer application research field.There are five sections in this paper. The user requirements and the development workflow of the system are introduced in the first section. In the second section, some key technologies to build the video conferencing system are studied, including audio/video capture, coding/decoding, playback, the transport of streaming media over the Internet, and NAT traverse. In section three, we build up use case model of the system. Section four introduces detail design of the system. In this section, some UML sequence diagrams or activity diagrams are given to demonstrate the implementation of the use cases. Some other technique details, including design patterns, threading and network programming, are also discussed in this section. The last section, section five, concludes this paper by summarizing the main work of this paper and proposing some improvements of the system.This system has the following features. First, it can traverse NAT. Second, it uses both multicast and unicast to transport streaming media. Third, following the use case driven process and OOA/OOD thinking, adopting N-tires architecture, making use of design patterns, this system is well structured and extensible. Forth, based on .NET Framework, this system has a short develop life cycle and is easy to debug and maintain.