Research & Implementation Of A Streaming Video-on-Demand System Based On P2P

With the rapid development of Internet technology and the increase of the Chinese Internet users's number, Internet Video-on-Demand (VOD) service has become one of the major services of the Internet. The traditional video on demand system is based on client/servent architecture, although its controllability and manageability is higher, the server's performance can often be the bottalneck of the VOD system's performance especially when a large number of users are watching online. When P2P technology is introduced into the video on demand system, VOD system can take full advantage of the idle resources of other peers (CPU, network bandwidth and storage resources, etc.), and thus effectively reduce the server's load and improve the scalability and stability of the VOD system. There have been some VOD systems which are based on P2P technology on the internet, but the problems of video's copyright, P2P users'management and P2P security are commonly founded in these VOD systems.In order to solve the above problems, an overall solution which is based on PMTN(P2P Media Telecom Network) framework has been propsed for the VOD system. Besides, a VOD system model based on PMTN framework is given, the key problems of this system have been researched and solved, and the VOD system prototype is implemented.This paper has the following contributions:(1) An overall solution which is based on PMTN framework for VOD system has been proposed. In this framework, a VOD system is divided into business operation layer, P2P management layer, user media layer and support layer. The P2P technology is mainly used in P2P management layer and user media layer. The business operation layer is independent form the P2P network, the business changes of the upper layer will not affect the data scheduling strategy of the P2P network.(2) Kademlia routing algorithm has been improved. In the new algorithm, the logical distance will be in keeping with the physical distance, so the chosen downloading peers will be neighboring peers.(3) In the super peer, static prefix caching combined with dynamic suffix caching strategy is used, in the normal peer, memory caching combined with disk caching strategy is used, and so forth, the startup latency of the client has been reduced and the hit rate of resources has been improved.(4) Taking into account the heterogeneity of the P2P network, all the peers are classified by the weighted speed method. When downloading the data, give priority to faster nodes, so the real-time performance and the playing fluency of the VOD system are ensured.(5)Taking into account the security of data transmission in the P2P network, a solution based on SSL protocol is proposed.(6) The VOD system prototype is implemented and tested.In the end, the conclusion is made and the future research is put forward.