Design And Implementation Of Online VOD System Based On P2P

With the development of internet, Network Application Services are gradually richer, Streaming media applications have increasingly gained public attention. Because of large of data and high requirements of network bandwidth streaming media, traditional C/S architecture demand used in the past does not satisfy the increasing demand, and it has appeared a range of problems, such as network bandwidth severely limited, high burden on the server and so on, so C/S architecture model has been unable to ensure the QoS of streaming service. Although the CDN technology can improve patency of the network, it has other problems such as high cost of inputs and poor scalability, so it is also not widely used.The emergence of P2P technology effectively solves network transmission problem. Its central idea is that all nodes in the network are peers, so while receiving the data needed the user provide services for other nodes, and network resources are used efficiently. In addition, the idea that network nodes are peers weakens the function of central network server in the network, and consequently greatly reduces the burden on the server. The dynamically update, robustness and scalability of the technology are superior to C/S mode streaming media system.The research, combined with the business needs of Liaoning Normal University Press Limited Liability Company, proposes and implements a streaming media system on the basic of P2P technology. Firstly, the paper introduces current situations of technologies related to media player, including P2P technology, streaming media technology and video encoding. Secondly, the demand proposed in the research is detail illustrated. Thirdly, the system is detail designed, the key functional modules in the system is described, and P2P part is designed through Bittoreent protocol, which performs well in practical application and works efficiently in distribution of data files.In order to ensure media to play smoothly and improve effectiveness, in the P2P-based online streaming media system, an innovative slice selection algorithm is designed so as to maximize the transmission effectiveness among nodes. According to the specific business needs, the server-side and client-side in the system both store media resources. The servers store media resources produced by the press company, while nodes store those produced by themselves. In the same time, the files of server-side are distributed and stored in each node so as to reduce the burden on the server, and when the storage space of node is in sufficient, the distributed resources are cleared and the sever also change media resources according to its own storage space. Thanks to distribution of server-side files, media files can be stored for a long period, thereby the service capacity of overall system is enhanced.