Research And Implement A P2SP Download System That Base On The CDN

Recent years the P2SP technology is a hotspot in computer research, whose downloading way essentially goes a step further than the P2P technology. It also integ ate the originally separate server resources into the P2P resources by downloading the resources database, so that there is a better downloading speed, more rich downloading resources and good stability. However, single P2SP application also has some shortage, the popularity of this business not only cause network tracfic storm,but also make the pirate and virus more furious for lacking of news surveillance as well as no any content and right management, so that it'll do some damage to telecom operators and their estate chain.On the other hand, as the traditional telecom operators,the CDN's content distributing newwork already run for many years, which has an entire suit of convenient network content and right management system, operable user management tool, guarantee-reliable QoS service and reasonable network flow-control. All of these complement the current P2SP techonology. however the core of CDN is still based on the centralized server structure, which tightly associated with area control so that it's hard to reduce its extension cost. And the traditional CDN is deficient in the adaptability and fault-tolerant ability when coming across network flow peak.CDN's development face to a severe challenge as the rapid increase of user scale. This paper is focused on how to integrate P2SP with CDN techonology logically, and then apply it into the design and implement of downloading system.The improved P2SP downloading system could make fully use of the transimission bandwidth to implement file downloading business,which is based on CDN network.It provide us high quality on file downloading service, and assure the service quality of the entire system by the downloading ability of the server when there are only a few user. It also make more efficient in content right,user management and flow sequence,which contribute to decrease the cost of file downloading.This paper begins by introducing the fundamental principle of the P2SP techonology, as well as its current research situation. The paper is mainly concentrated on P2SP network model and CDN's content distributing network techonology, and make a comparision between their feature,advantage and shortage, then put forward an idea which is related to integrate this two techonolies efficiently to generate perfect effect.It also provide a new downloading system model that is based on CDN,and then make a detail analysis on the property and chacteristic of the model.Furthermore, according to the actual application requirement,this paper implements the system from the system layer,involving the design of the server side and client side.This paper also make a discussion on the safe hash aogrithm SHA1, and applies it into the system to compute the file ID,which well resovle some techonology difficulty, such as the management during downloading process and accelerating the resource utilization.