面向单向广播网络的可靠多播文件分发服务研究和实现-计算机应用技术专业毕业论文.docx

浙江大学坝Jj学位论文Abstract 浙江大学坝Jj学位论文 Abstract 、Mth the rapid development of amount of network subscribers．the effective delivery of hot data content ifl the way of one to many iS regard as an very import requirement．UnidirectionaI broadcast network，such as CATv，iS a natural bom content delivery notwork，more and more people pay attention to the service of IP data broadcasting and content delivery over CATV,it iS an important research and application field that how to design and implement a file delivery service which iS packet-loss-sensitive over unidirectional network like CK烈． In this paper,we take a deep analysis and research on application and technology of IP reliable multicast file delivery service system．then prosent a solution of reliable multicast file delivery over unidireetional network．Based on ALC／FEC reliable multicast protocols．we analyzed the specialty of Unidirectional notwork such as CATV,and successfully design and implement an unidirectional network oriented reliable multicast file delivery system，achieving hi曲ly effective and reliable transmission and receiving．Modules of the system which iS layered as reliable multicast tfansport layer,file operation layer and sessions SCheduling and mariagement layer iS fully described．several key problems in the process of implementation iS focused and alSO fully described． The innovation of our wok iS that we build a new application of ALC in CATV which iS an unidirectional network，and adjust the work parameters of this system， according to the characteristic of C删At the same time．we prosent an algorithm of restraint and smoothness scheme for instant pulse of many transmission rate。and also find a good solution for dynamically adjustment of the action of receiving threads according to the performance ofhost computer． The system has been already implemented and successfully applied in practice． PC users can experience reliable file downloading at high speed witll QoS assurance by access to the CATV network usin