Fast Data Transfer Method Based On Overlay Networks

Internet is based on many autonomous systems, which provides'Best Effort'service. Data transfer between two hosts usually should go through several autonomous systems. But in the scene of'Best Effort', a lot of applications are unable to deploy and expand. Under this circumstance, overlay network was proposed. Overlay networks can meet clients'distinct demand, however, it doesn't need to change or cosmically change the current network structure. Because Internet is based on autonomous systems, Internet repairs the faulty of routing is quite slow, reliability is not very high. The speed and reliability of data transfer is unable to satisfy clients'demand. In face of this problem, this thesis design and implement a data express system (Express overlay network, EON), which used for data fast transfer between hosts.In this thesis, firstly does some research on characters of overlay networks and introduce the applications based on overlay networks. After the introduction of the concepts of overlay networks, the thesis researches the current overlay routing. It classifies the overlay routing from application layer, transport layer and network layer of network, then presents the application of the corresponding layer, which is using in the design of EON.Secondly, the thesis designed and implement EON. EON is used for fast data transfer between EON nodes, and it solved reliability, reachability and transport performance of data transfer. EON is composed of Flooding, Member, TcpLink, Session and Routing. Through Flooding and Member, it realizes the operations of nodes'join and quit etc.. Based on period flooding and probing, it checks-up the fault nodes quickly. And it feedback the fault node to routing module, guiding for route selection, bypasses the fault nodes. When transport data, using parallel multipath routing, deploying data on multipath, however, improved the efficiency of data transfer. In order to avoid the problem of unreachable because of path failures, EON provides substitute routing mechanismAt the end of the thesis, using GT-ITM generate the topology of the simulation. Then it makes comparison between EON and the ordinary data transfer, which shows that no matter in transport time or in packet lose rate EON does better than the ordinary data transfer. It shows the efficiency of EON.