Applications of P2P

The P2P model is used by a number of networking protocols such as SMTP (email) and NNTP (Usenet news). More popularly known however – especially recently – is the role of P2P in file sharing networks that enable the free and relatively anonymous exchange of local files between computers connected to the Internet.

Certain file sharing networks like Napster, IRC @find and OpenNap have some functions such as search queries on a client-server structure, but the file sharing itself is done through peer-to-peer. Gnutella and Freenet, on the other hand, are examples of true peer-to-peer networks because the structure of their respective networks are based entirely on peer-to-peer.

A crucial feature of P2P networks is how the combined bandwidth of each connected client is leveraged by the entire network for file transfers. This means that the bandwidth available to the average user grows wider as more nodes connect to the network. In contrast, users exchanging files on a client/server network have to divide the available bandwidth (between their computers and the central server) among themselves, resulting in slower data transfer rates when more clients are connected to server.