MODELLING CLUSTERED PEER-TO-PEER NETWORKS

摘要

In the world of Peer-to-Peer (P2P) networking different protocols have been developed to make the resource sharing or information retrieval more efficient. The SemPeer protocol is a new layer on Gnutella that transforms the connections of the nodes based on semantic information to make information retrieval more efficient. However, this transformation causes high clustering in the network that will decrease the number of nodes reached, therefore the probability of finding a document is also decreased. In this paper we will describe a mathematical model for the Gnutella and SemPeer protocols that takes clustering issues into account, followed by a proposition to modify the SemPeer protocol to moderate clustering. This modification is a kind of link management for the individual nodes that causes the SemPeer protocol to be more efficient, because the probability of a successful query in the P2P network is reasonably increased. For the validation of the models we made a series of simulations that supported our results.