Research On Virtual Logical Topology Of The Network And Resource Search Algorithm To Chord Based On

Among structured Peer-to-Peer systems, Chord has a general popularity due to its salient features like simplicity, high scalability, small path length with respect to network size, and flexibility on node join and departure. As we know, the key problem in P2P network is effectively to locate resources. However, Chord doesn’t take into account the topology of underlying physical network randomly allocated node’s logical ID when a new node is being added to the system, thus resulting in high routing latency and low efficiency in data lookup. So it is critical for a P2P routing algorithm to be aware of the network physical topology, which leads to improvement of the routing efficiency.Structured P2P networks create a virtual topology on top of the physical topology. The only relation between the two layers exists in the Hashing algorithm, because of Hashing-algorithm’s properties, which makes a node’s logical ID independent of its physical location. By analyzing the Hashing function and P2P networks’s properties, some novel logical connections are presented among the routing destination node: the relay node sequence in the process of Chord routing, and the clustering neighbor nodes which based on topology information.In this paper, we introduce a new P2P network based on Chord which called the PT-Chord (physical network topology aware based Chord protocol Peer-to-Peer Network), a novel topology aware based Chord protocol. PT-Chord introduces the local ring concept by dividing the geographical space into smaller areas by the way of account the topology of underlying physical network, clustering nodes in P2P networks form local rings according to the division of the area. Through binding each new node to a proper local ring concerning its physical location, and design a more effective routing lookup algorithm which match to PT-Chord network, limit research message reasonable on the local loop, reducing the number of routing hops and the routing delay, merge the redundant information in the routing-table to improve the efficiency of the routing-table queries. PT-Chord considers the physical network topology of the overlay network to demonstrate more efficient key lookup, smaller query delay and better load balancing. Analysis on theory and simulation results show that PT-Chord performs better in terms of more efficient routing and less bandwidth usage.