Resolving Names in Peer-to-Peer Networks

Efficient peer-to-peer networks maintain all-to-all connectivity while eliminating redundant network links. Microsoft’s Peer Name Resolution Protocol (PNRP) sets up and maintains peer-to-peer networks by assigning numbers to nodes as they join the network. The protocol can then dynamically add and remove links in the network to maintain connectivity among all network nodes.

Each node in a PNRP network stores the IDs of other nodes in a cache, but this cache is kept deliberately small to save resources and eliminate the need for constant network communications, which would be necessary to maintain a current list of all nodes in a very large network. In the illustration, a dotted arrow from one node to another means that the node from which the arrow originates has an entry in its cache for the node to which the arrow is pointing. The illustration shows how a new node, Peer A, uses PNRP to join an existing P2P network by discovering the IP addresses of other computers and setting up links to them.