Most of structured P2P overlays exploit Distributed Hash Table (DHT) to achieve an administration-free, fault tolerant overlay network and guarantee to deliver a message to the destination within O(logN) hops.While elegant from a theoretical perspective, those systems face diffi- culties under an open environment. Not only frequently joining and leaving of nodes generate enormous maintenance overhead, but also various behaviors and resources of peers compromise overlay performance and security.

Instead of building P2P overlay from the theoretical view, this paper builds the overlay network from the perspective of the physical network. By combining different network topology-aware techniques, a distinctive overlay network that closely matches the Internet topology is constructed. The P2P system based on this structure is not only highly efficient for routing, but also keeps maintenance overhead very low even under highly dynamic environment. Moreover, the system provides a new aspect to solve many security issues.