Research, Network Streaming Data Transfer Mechanism

With the continuous development of Internet technology, it's becoming possible to provide large-scale streaming media services under the existing networks, and it appears a lot of research on it. Streaming service has the characteristics of large number of nodes, large data volume and high real-time requirement, simple C/S structure has been unable to meet its requirements, while with the characteristics of scalability, robustness and load balancing, Peer-to-peer(for short P2P) became one of the most effective technologies to realize large-scale streaming media service.In this paper, we mainly research on data transport mechanism of P2P streaming media system, the main work includes:First, from a point of view of system, this paper summarized several key problems of research of P2P streaming system, including node dynamic, node heterogeneity, scalability and data scheduling strategies, and presents an analysis on these issues.This paper generalizes the model and related algorithms of P2P streaming system. Three main issues of data transmission of P2P streaming media system are sum up, first is locating of data blocks, how to effectively query the node which has cached a certain data block; second is the problem of establishment of overlay, how to organize the nodes can meet the request of scalability and robustness; the third is data scheduling problem, it mainly solves in what order request and download data blocks can keep continuity of video playback and low startup delay. In addition, we outline and analyze main performance indexes of data scheduling, and use playback continuity and startup delay as main performance indexes.Finally, this paper presents UR data scheduling strategy. UR scheduling strategy comprehensively considers two main factors of data scheduling: urgency and rarity, defines a priority according to both factors, presents high-speed nodes contribution mechanism, emergency schedule mechanism and low-speed nodes limitation mechanism, and successfully applied these three mechanisms to the new scheduling strategy. From both theoretical analyze and simulation results, the proposed improve mechanisms and overall scheduling strategy can improve the continuity of video playback under an acceptable startup delay, achieve a good effect.