A Bidirectional Ring Cluster-based Peer to Peer System

File sharing and replication presents a challenging issue due to the unreliability nature of the wide area network. Peer-to-Peer systems are emerging as a new paradigm for structuring large-scale distributed systems. Different architectures of Peer-to-Peer systems, inherent with some advantages and disadvantages, have been proposed for applications such as file sharing, storage management or digital library which benefit from the cooperation between peers. This paper proposes a bidirectional ring cluster-based peer to peer system (BRCPPS) architecture which includes two parts: a bidirectional ring as backbone and some clusters connected to the ring through their cluster head nodes. The ring nodes act as lookup entry for out-cluster query. Bottom tier nodes self-organize into a Gnutella-like cluster and select one high performance node as their cluster head. Each cluster is a relatively smaller Gnutella network. The ring nodes don t act as index server of clusters and contain no files and replicas index of the cluster, but they plays an important role of transmitter for out-cluster query messages among clusters. The bidirectional ring has more reliability and ensures efficient lookup.