Design And Implementation Of P2p-based Video On Demand System

With the development of multimedia and network technology, media streaming is becoming the mainly driving force for the broadband network applications. In the traditional C/S streaming system, the server often becomes the bottleneck due to the high bandwidth and long duration of multimedia streams. How to distribute streaming media content to a large number of hosts in a scalable way has become the key problem. In order to solve this problem, P2P technology is introduced to the VoD system to reduce the burden of server.The purpose of VoD system based on P2P technology is the decentralization of service. All the peers in the system are both the consumers and providers. There are tracker server and video server in the system. Tracker server records all the information of peers according to the video they are watching respectively. Video server transfers the video data to the peers in the system. When a peer joins in the system, it should register on the tracker server and get the information of other peers which enjoy the same video. Then it should connect to the video server and other peers to request the video data. All of the peers provide the data to others when they get. This technology makes full use of all the resources in the system to get the purpose of reducing the burden of server.The characters and development of P2P technology are firstly introduced in this thesis. Secondly, the system topology is described. Thirdly, the feasibility of transferring the file-sharing system to the VoD system is analyzed and the interaction between STB and tracker server is presented. A data request mechanism, which leverages the advantages in both P2P and C/S, is proposed and emphasized. It can be considered as the combination of decentralized and centralized request mechanism. The function of the system and the performance of the mechanism are evaluated through test. At last, system traits and deficiencies are summarized, and next tasks are pointed out.