Abstract
Most P2P file-sharing systems are unable to create self organizingcommunities of similar nodes that provide goodservices to their members. In this paper, we propose aGnutella-like file-sharing protocol based on the premisethat each peer only creates links with the best counterpartswhich the peer has discovered in the network. TermedAdaptive Gnutella Protocol (AGP), our proposal transformsthe overlay topology based on a reputation scheme thatevaluates the provided services and offers a mechanismthat organizes trusted nodes with similar content. We haveimplemented the AGP protocol using the PeerSim engineand conducted experiments on diverse network topologies.Over time, the network topology improves as every peer locatescounterparts with similar content and good reputation.Moreover, malicious nodes are pushed to the edge ofthe overlay network and are excluded from participating inthe AGP search.