Research And Implementation Of The Node Of Media Layer In The Distributed Service Network

Distributed Service Network (DSN) is a new type of communication network. It is a promising form of the next generation mobile communication core network, which is a P2P network composed of service nodes. In traditional DSN, the media path between the two users is an end to end one over IP network. However, the IP network can't guarantee the qualities of the communication, and it becomes even a nightmare when 3G users increase that fast, makes the user experience worse, becomes the bottleneck of network, and will restrict the development of the network.In this paper, the problem of the media path on the media plane in DSN is analyzed and a solution for the problem is also brought forward. In the solution, several media relay nodes in are added onto the media plane. To specify the solution in detail, DSN is first introduced, including the architecture and the communication flows. Media communication is paid more attention on to illustrate the disadvantages of the traditional media communication mechanism. Then Media Gateway Controller (MGA) and its working processes are specified. Based on the analysis, a new solution of media communication is proposed, in which a new network entity, Media gateway Proxy (MP) is introduced into the network. In this solution, many MPs are deployed in DSN, which are self-organized and provide a set of functionalities such as media path construction in the core network. MP network is used to improve the quality of media communication. After the MP network accepts the request, it will choose some MP nodes to construct the media path, and can guarantee the media connection quality could be better than the end to end connection. To support MP, DSN is to be modified. To make MGA support MP is first considered and the new communication protocol and the control interfaces are designed. As to the design of the MP, the requirements of MP are first specified and then modules, interface, protocols and control flows of the MP are designed. In the end, the implementation and the tests of MP are introduced. From these tests, it could be seen that MP could work well, improve the quality of media connection.