Study on a structured P2P routing algorithm considering physical network latency

Chord [1] has been widely used as a routing protocol in structured peer-to-peer overlay networks. The neighbor peers in Chord are defined by logical address and there is no necessary causality between logical address and physical address. It may appear a “detour” phenomenon which reject what is near at hand and seek what is far away in the physical layer. This paper proposes a strategy that considers physical network latency presenting the distance in physical layer to some extent. The improved routing algorithm chooses the next hops based on both logical distance and physical latency and makes a trade-off between them. Theoretical and experimental analysis shows that Latency-based Chord can improve search performance effectively.