Research On Resource Locating Model And Other Key Technologies Of P2P Network

Since the birth of P2P technology at the end of the last century 90's, it has begun to the rapid development and is widely used. Resources locating is a key issue of P2P network and a research hotspot as well. Based on the network topology, the resources locating model of P2P system has gone through the first generation of centralized topology network, the second generation of full-distributed unstructured network and the third generation of DHT-based full-distributed structured network.Although the application of P2P technology is increasing, it still faces some challenges in the course of development.Through understanding of both at home and abroad researches, analysing DHT technology and several typical structured resource locating models of P2P network, such as Chord, CAN, Pastry and Kademlia, this paper summed up some issues needed urgently to be solved for resource locating model of P2P network.Firstly, for the topology's mismatching of structured P2P between the overlay and the physical network, this paper has presented an algorithm to create a physicallocation-based structured overlay network. The algorithm uses the adjacent relation of nodes in the same autonomous system to make the neighboring nodes in the the physical network still neighboring in the overlay, so as to enhance the efficiency of routing.Secondly, aiming at the instability of hierarchical resource locating system that is caused by supernode's malicious leaving and malicious actions, the paper has brought forward a trust-based supernodes' selection method, which introduces mechanism about trust in process of the supernodes' selection, and select those nodes with high trust and strong ability as supernodes. This can reduce the impact of P2P systems that is brought by supernodes' malicious leaving and malicious actions, and also can improve the quality of services provided by P2P.Finally, basing on the Chord, the paper has also designed a hybrid resource locating model with double hierarchy, be short for DHDChord,it's logic layer is built by ALDHT algorithm ,and the supernodes are selected by TSSM . DHDChord is composed of two layers Chord ring with an inside ring and an outside ring。the outer ring devides the nodes into groups, the sub-group nodes use the improved fingertable and manage themselves,the interior ring providing global routing is made up of supernodes of the groups.It is mainly concerned about four issues at aspects of the topology's mismatching between Chord's overlay and it's physical network,the node's heterogeneity, fingertable's redundancy and stability of system, with an emphasis from aspects of the topology design, fingertable design, routing algorithm, nodes' joining and leaving,supernodes' maintenance and fingertable's maintenance discussed in detail...