Large-scale Streaming Media Distribution Based On Virtual Agent Technology Research

Streaming services have become a mainstream Internet application. The use of P2P technology in streaming media systems to improve scalability, concurrency and robustness are facing a lot of problems. Such as crowding backbone networks, imperiling resources security and pirating content copyright and many other issues. As a result, most of service providers use the technology of CDN to build their own streaming media services platform. CDN which can effectively control the streaming resources is set up on the Internet through a number of scattered edge proxy servers. These proxy servers cache the streaming media content which user requests. But the high cost of network expansion can not meet the large-scale service request. So a hybrid topology of P2P and CDN streaming media system has become the mainstream. The integration of the advantage of low cost expansion for the P2P and safety management of CDN meets the large-scale service request. But the general P2P-CDN architecture’s service capabilities continue to be limited by bandwidth of proxy server; and despite the introduction of P2P technology, because of a requested resource nodes are ordinary user nodes that cache size is generally not high, and the cache resource information are relatively close to the playing time, and the current proxy server seldom monitor the time which peers request. All these make the P2P network low efficient to find the resources. Establishment of a centralized directory-type, or structured P2P networks can improve search efficiency. However, these will not only increase the burden on the proxy server, but also request ordinary peer a higher computing ability.This paper describes the knowledge of streaming media before, and then studies the existed distribution technology, focus on the analyses of existing P2P-CDN hybrid topology. The central work can be summarized as follows:1) Introduce the concept of virtual surrogate, virtual surrogate is proposed based on the two-story content distribution model. Namely, by selecting some of the high-energy, stable peers to act as secondary proxy roles, share part of the proxy server functionality. Peers according to user requests and data segment is divided into different P2P network. They are logically grouped into one net. Helps the surrogate server batch distribution tasks, and improve the efficiency of access to resources between peers.2) Studies the distribution and cache strategy of proxy servers and virtual surrogate server, design a virtual surrogate server selection algorithm and add history contribution into concerned.3) Make a detailed study on existing data block scheduling algorithm on P2P. Proposed an Optimized Task Assignment Algorithm of multiple senders in server pool. The service peer will be requested to take abilities about request peers into account. Improved the bandwidth allocation algorithm. Makes high-energy nodes can access services more quickly, thereby increasing the spread efficiency of resources across P2P network and capabilities of service. Finally, the detailed design of key modules and actualize of it were carefully described. Compared with the traditional CDN network, an experimental and test data were analyzed and explain. Experiments’results examined that the new module and algorithm has improved the system capacity and clearly shortened the startup delay.