Proximity-Aware DHT for Efficient Lookup Service in Peer-to-Peer Applications

Distributed Hash Tables (DHTs) attract considerable attention as a way of realizing an efficient lookup service in Peer-to-Peer (P2P) applications. However, many of conventional DHTs such as Chord and Kademlia do not take into account the proximity of nodes in the physical network, which causes a significant performance degradation as the size of the underlying network grows. In this paper, we propose a method to construct a proximity-aware DHT based on the notion of virtual coordinate space realized by a network coordinate system (NCS). The performance of the proposed method is evaluated by simulation. The result of simulations indicates that it reduces the average physical distance between adjacent nodes in the P2P overlay by 10% for random or scale-free networks, and by 80% for grid-structured networks.