Exploiting the Overhead in a DHT to Improve Lookup Latency

Third generation Peer-to-Peer (P2P) networks are characterized by the fact, that they are based on Distributed Hash Tables (DHT). Thus, it is intended to reduce the high signaling overhead observed in unstructured P2P networks like in Gnutella. However especially if the churn rate in the considered approach is high, i.e. nodes leaving and joining the network frequently (small session duration) the signaling traffic needed to maintain the DHT structure increases considerably. In the Chord protocol, which is investigated in this work, so called fingers are used to establish shortcuts though the DHT structure to achieve a scalable routing performance. To keep these fingers up to date in regular Chord, a significant amount of signaling traffic is necessary, especially in high churn scenarios. Therefore we propose a new scheme which provides additional finger update methods without causing additional traffic.