Most of current structured P2P systems exploit Distributed Hash Table (DHT) to archive an administration-free, fault tolerant overlay network and guarantee to deliver a message to its destination within
) hops. While elegant from a theoretical perspective, those systems face difficulties in a realistic environment. Instead of building P2P overlays from a theoretical perspective, this design tries to construct an overlay from the physical network. By combining different network topology aware techniques, a distinctive overlay structure closely matching the Internet topology is created. The P2P overlay based on this structure is not only highly efficient for routing, but also keeps maintenance overhead very low even under highly dynamic environment.