Date Added: Apr 2012
The "Peer-To-Peer" (P2P) networks refer to a class of systems and applications that employ distributed resources to perform a function in a decentralized manner. Unstructured Peer-To-Peer networks do not impose any structure on the overlay networks. Peers in these networks connect in an ad-hoc fashion. Ideally, unstructured P2P systems would have absolutely no centralized system, but in practice there are several types of unstructured systems with various degrees of centralization. In heterogeneous decentralized unstructured P2P networks peers join and leave the application at their own will in an uncoordinated fashion and a central index for resource location is absent. Each peer is only responsible for maintaining a local index of the resources it owns and it is willing to provide to others.