Based On Secure Multicast Conferencing Systems Design And Implementation

With the development of communication technologies, many new applications come forth continuously, such as multimedia conferencing, distributed systems, computer cooperative work and so on. Multimedia conferencing gradually becomes one of research hotspots. There are two types of multimedia conferencing systems in the world at the present which are H.323 protocol-based multimedia conferencing system and IP layer multicast-based multimedia conferencing system. However, there are some flaws on the two types of systems. One can not make use of the network bandwidth efficiently, and another has some problems about security.In this situation, this thesis is based on the project of national 863——"end to end virtual circuit-based network security architecture", developing an secure multicast-based multimedia conferencing system. Compared to other conferencing systems on the market, this system has many advantages. Firstly, the system improves the quality of data transmission, and reduces the phenomena of network congestion; Secondly, the system is composed by software fully instead of any hardware, which saves the cost of the system; Finally, the system solves most of the problems about security which the IP layer multicast faces. Besides, the system not only can run on IP layer multicast, but also can run on application layer multicast. This character makes the system improve the flexibility greatly. At the present, the entire system and the network model have passed the test of software evaluation center in Sichuan.This thesis is organized as follows:1,This thesis introduces the situation of related research in the world, then it describes the goal of the system designing and the advantages of the system.2,It introduces the concepts of end to end virtual circuit-based network and multicast. In addition, it describes the basics of multimedia transmission, as well as basics of programming.3,It describes the basic functions which are implemented by the multimedia conference system, then it introduces the basic principles and implementation ideas from two branches which are IP layer multicast and application layer multicast. 4,It introduces the overall system architecture and data flow, and analyzes a key part of the system: thread pool. And then it describes the detailed design and implementation methods of the various parts of the system.5,Finally I do a test for the system, and the results shows that the system is running on the end to end virtual circuit network security architecture with a highly efficient and stable transmission performance. And it solves the multicast secure access and data security issues effectively.