Research On Download Technology In P2P System

With the development of Internet,the deficiency of the Client/Server architecture in information sharing gradually emerges.The central server is hard to afford the huge access from the network,and the central failure is becoming a serious problem.There are huge computation and storage sources at the edge of the network,but under the C/S mode,these sources are left unused.This prompted the Peer to Peer calculation(Peer to Peer referred P2P), somebody predicted that the peer-to-peer will become the basis for the Internet in the future.And the largest application area of P2P technology is file-sharing,it is necessary to study the download technology it involved.In this paper,studied the download technologies involved in the P2P system, including:1)establish connection,introduce details of the NAT and its four types,and the related methods of NAT traversal of TCP,and improve the method TCP hole of NAT traversal,this method reduce the burden on the server,improve the system scalability.2)related download speeds studies,introduced the packet delay and the fairness of the TCP,and the resulting increase download speeds of two of the ways,one is to minimize the number of jump routing strategies,that is local sub-network of Node first selection,the same Types of network nodes second selection,different types of network nodes final selection,the other is multi-threaded download strategy.3)ensure the integrity of downloads,to avoid abandoned the download document did not complete because of the resources provided nodes left the system, proposed mandatory strategy and virtual resources strategy,ensure the downloader can download the integrated required resources.Virtual resource strategy also can increase download speeds.