| With P2P applications rapid development, P2P network traffic is now taking up the majority of internet traffic in all,and this percentage is increasing. Because of the oblivious to the underlying Internet topology and routing, as well as the randomicity durning the peers'selection, greatest traffic-engineering challenges for ISPs, AS and the source of costly data traffic flows become extruding. This frequently cross-net traffic has already become a big pressure to the underlying physic links and also brought a lot of system's sacrificing. Cross-net traffic such as cross-ISP traffic does happen mostly because of the oblivious to the underlying physic topology. In conference ICDCS and sigcomm in 2008, David R. Choffnes and his team bring forward the relative network positioning verdict in distribute system such as P2P called: CRP (CDN based Relative network Positioning).The core of CRP is: using the structure and mechanism of CDN net, recycles network views gathered at low cost from CDN to generate relative network positioning (CRP) and then to get the relative distance between nodes in distribute system. Due to the high utilization factor of the CDN nets, the CRP is famous by his low costs, lightweight and better performance. And therefore do a lot of advantage to the distribute system such as P2P.This paper aiming at the current structured P2P system's oblivious of underlying Internet topology and physical location. Firstly,considering of the factor of the P2P system , based on the traditional CRP mechanism, this paper advance a new mechanism called M-CRP which is more adapt to the P2P mechanism. This M-CRP improves CRP from aspect of efficiency, precision and performance with multi -level mechanism, which make the node in P2P, has more perception to the underlying topology. Secondly,with M-CRP and based on traditional CAN, this paper advance a new mechanism called M-CRP-CAN which make full use of M-CRP and make not only the CAN framework structure award of the physical location of nodes,but also the routing mechanism give more thought about the physical topology. The self-adaption can make the M-CRP-CAN has more ability to change according to the net status. In NS2 network simulation platform, theory analysis and the experimental results show that M-CRP's performance is better than CRP in aspect of efficiency and precision. In the meantime the M-CRP-CAN with M-CRP approach has realized localization download and greatly raised the data transfer rate, reduced the cross-traffic in backbone network and improve the network performance therefore enhance P2P system efficiency. |
