A survey of peer-to-peer networks

Abstract—The limitations of client/server systems become evident in large scale distributed environments. In such systems individual resources are concentrated on one or a small number of nodes and in order to provide access with acceptable response times sophisticated load balancing and fault-tolerance algorithms have to be applied. Also limitation on the network bandwidth adds the bottleneck problem. These problems have motivated researchers to come up with approaches to distribute processing loads and network bandwidth among all nodes participating in a distributed system. Peer-to-Peer systems offer an alternative to traditional client/server systems that solve bottleneck problems but need complex algorithms. This paper provides an overview on different p2p architectures and compares them with each other regarding some issues such as scalability, fault tolerance and manageability. P2P systems constitute highly dynamic networks of peers with complex topologies that create an overlay network. P2P applications need sophisticated discovery mechanisms to enable peers to find, identify and communicate with other peers. We discuss the discovery mechanisms in p2p systems which are based on the topology of the network and study the potential challenges in p2p networks such as reliability, security and adaptability