Study On Incentive Mechanism Of Peer-To-Peer Applications Based On Gnutella Protocol

P2P is the abbreviation of peer-to-peer. It means peer-to-peer network or peer-to-peer computation model. It is a kind of network model and every node is in the same import. The programmer Justin Frankel working in AOL developed a free peer-to-peer software-Gnutella. As the Gnutella is a nonstructural network, a large number of users and simplicity, it becomes a focus gradually. Gnutella is not only a file sharing application system based on peer-to-peer, but also is a file sharing protocol.However, the development of Gnutella is unsmooth because of the Free-riding. Free-riding means more and more nodes do not share but only get. This problem gives a negative pressure to development of peer-to-peer network.This paper is based on the analysis of basic of peer-to-peer network and protocol of Gnutella and summary the incentive model of peer-to-peer to find a solution to solve the problem above. It improves the old incentive model of peer-to-peer and brings forward a new incentive model which is based on the quality of service. Its content is divided two steps:First, to evaluate the contribution of each node and save, it is the essential issue. This paper is evaluating the contribution from two factors: the scale of uploading file from one node, the number of transmitting message.Second, to provide different service by different bandwidth is the method to execute the service differentiation. This paper gives a new method-I-progressive filling to distribute bandwidth for every node. This method provides better service to good contribution node and uses the limited network bandwidth as much as possible. In addition, this method also takes into account the degree of satisfaction which guarantees the distribution of fairness.Through the NS simulation, the experimental results show that I-progressive filling is incentive, under the same conditions as the maximum downloading bandwidth, the node which makes greater contributions to the system acquires bigger downloading bandwidth, on the contrary, the less downloading bandwidth. In addition, the mechanism uses the bandwidth as much as possible.Thus, the peer-to-peer network can provide service differentiation to every node by its contribution the network. The node which wants to get more service should provide more resource and forwards more transmitting messages to the system. This method incentives every node to make contribution to the system and improves the system efficiency hardly.