【作者】 吕斌；

【导师】 庄雷；

【作者基本信息】 郑州大学 ， 计算机软件与理论， 2011， 硕士

【摘要】 随着宽带业务的广泛发展,流媒体服务在互联网中所占的比重越来越大,出现了大量的流媒体应用,如网络电视、体育直播、远程教育等。在传统的流媒体应用系统中,大多采用基于C/S的服务模式,服务器分发全部的数据,客户端只是简单的接收数据并播放。当用户数量达到一定程度后,服务器就不能很好的为用户服务了,甚至出现单点失效的状况。在这种情况下,P2P技术的运用为这一问题带来了曙光,成为学术界、工业界研究的重点。目前,互联网的流媒体业务大体可以分为下载、直播、点播三类。基于P2P技术的下载系统和直播系统已经比较成熟,由于点播系统的高度交互性和播放异步性增加了系统实现难度。因此,在互联网上构建可扩展、高可靠、高播放体验的点播系统一直是研究的热点问题。本文主要贡献以及内容包括：首先,提出一种基于历史带宽的数据调度算法。这个算法综合考虑了节点带宽、节点服务能力、数据块候选节点数等因素,充分的利用了节点的带宽,减少启动延迟和传输延迟,提高了播放连续性。其次,设计一种节点优化机制。节点每隔一段时间就会优化与邻居节点之间的连接,通过统计邻居节点向自身发送的数量,来淘汰劣质的连接,建立优质的连接,提高系统的分发效率。最后,提出两级缓存管理策略。在内存中缓存即将播放的数据,提高播放的流畅度。同时在硬盘中缓存多部已播放过的视频,可以增加节点的服务范围,进一步降低服务器的负载,减少运营成本。并且设计和实现了基于P2P网络的流媒体点播系统,并给出了相关技术的测试结果。更多还原

【Abstract】 With the widely development of broadband services, the propotion of streaming media services on the internet services has been increased, and a lot of streaming media applications appeared, such as network television, live broadcast, distance education etc. On traditional streaming media, most of the application system based on the c/s model, the server of data distribute data to all clients while the clients simply receive data. When the user number increased to some point, the server could not serve users well, even a single point failure will appear. In this case, the use of p2p technology brings the dawn for this issue, and became the key point in research of both academic and industry. At present, the stream media business can be divided into general streaming media downloads, live broadcast, demand three categories. The download system broadcasting system based on P2P technology have been developed, because of the interaction and broadcast asynchronous, the implementation of the broadcast system on demand has been increased. Therefore, to build expanded and high reliability, high experience of the broadcast system on demand on the internet has been a hot issue.The contributions of this thesis include:First, we also raised one algorithm based on historical data bandwidth which combined comprehensive consideration, such as, node bandwidth, node service capabilities and candidate nodes number, etc. The full use of the bandwidth reduces both the start delayed and transferring latency, improve the continuity of play.Secondly, a node to node optimization mechanism was raised.the connections between the nodes will be optimized at intervals, a node evaluates the inferior quality of connection to its neighbor by the statistics of the date quantity from that neighbor, to improve the system connection and distribution efficiency.Finally, the two levels management strategy was raised. In memory caching, data are stored to improve the fluency of the play, meanwhile, in the disk cache many video that have been played are also stored to widen the service range of this node to further reduce the load of server and operation costs. Besides, Design and implementation of P2P-based streaming on-demand network systems and related technologies are given the test results.更多还原