Javad Taheri - Advanced Information Technologies Lab. Department of Computer Engineering and IT Amirkabir University of Technology, Tehran, Iran
Mohammad Kazem Akbari - Advanced Information Technologies Lab. Department of Computer Engineering and IT Amirkabir University of Technology, Tehran, Iran

Among structured Peer-to-Peer systems, Chord has a general popularity due to its salient features like simplicity, high scalability, small path length with respect to network size, and flexibility on node join and departure. However, Chord doesn’t take into account the topology of underlying physical network when a new node is being added to the system, thus resulting in high routing latency and low efficiency in data lookup. In this paper, we introduce the TAC, a novel topology-aware protocol which is based on Chord. TAC introduces the local ring concept by dividing the geographical space into smaller areas. Through binding each new node to a proper local ring concerning its physical location, TAC considers the physical network topology of the overlay network to demonstrate more efficient key lookup. Simulation results show that TAC performs better in terms of more efficient routing and less bandwidth usage.

Peer-to-Peer Systems, Routing Efficiency, Topology Awareness, Chord