【作者】 符丽姹；

【导师】 林中；

【作者基本信息】 北京邮电大学 ， 机械电子工程， 2008， 硕士

【摘要】 随着网络技术的的日益发展,人们的生活中越来越离不开Internet,全球的电信运营商也将目光集中在宽带网上的各类增值业务。其中,基于流媒体技术的IPTV服务有着广阔的应用前景。传统的IPTV服务采用的是客户机/服务器(C/S)结构,随着用户数量的增加,服务器的负载越来越重,而服务器本身的处理能力和带宽有限,因此容易造成“单点实效”,系统的可扩展性差。P2P技术不同于以服务器为中心的C/S传输模式,其采用的是对等网络模式:网络中的节点即可以获取其他节点的资源,又充当服务器为其他节点提供资源。这种模式将服务由中心推向了边缘,充分利用网络中各节点的资源,极大减轻了系统服务器的负载,这些特点都极大促进了基于P2P的流媒体系统特别是IPTV的应用和发展。本文首先介绍了P2P三代网络体系结构,技术特点及流媒体相关方面知识。其次,重点分析了Bittorrent系统组成及其协议,并根据流媒体传输的特点,对Bittorrent的部分算法进行改进。最后结合Bittorrent协议,将传统的IPTV系统中的内容分发网络(CDN)模式和P2P进行有效融合,设计了一种适合部署和运营的P2P结构的IPTV系统,有效解决了原IPTV系统的扩展性差、资源利用率低和系统吞吐性能不高等问题。同时,为实现系统的跨平台运行以及往机顶盒上移植,系统使用跨平台的ACE网络库编写,可以支持Linux、Windows、Solaris等系统。更多还原

【Abstract】 With the development of network,Internet become one part of our life gradually.More and more Telecom service providers around the world pay attention to the value-added service.Especially the service of IPTV which base on streaming has a brighter future. In the past,the service of IPTV adopt the standard structure of C/S (Client/Server) .The structure of C/S has a fatal limitation that likely to get overloaded and has a single point of effectiveness which affected by the limitative processing capability of server and the bandwidth.The structure of Peer-to-Peer changes the mode of server-centric and makes every Peer equivalent in the network. Every Peer offers service for other Peers at the same time enjoys the services provided by other Peers. So IPTV based on P2P solve the problem of traditional IPTV service, and greatly boosts the application and development of IPTV.This paper recommends the anciently structure and technic character of P2P and the knowledge of streaming firstly. Then focus on the system composition and the protocol of Bittorrent. Then improve the piece-picker arithmetic of Bittorrent according to the feature of streaming. Ultimately unify the merit of traditional Content Distribution Network and P2P, produces an IPTV system great at deployment and operation. For the sake of transplanting to the set-top box, the system base on ACE that support for Linux, Windows, Solaris systems.更多还原