Cyclic routing: Generalizing look-ahead in peer-to-peer networks

Distributed Hash Tables (DHT) provide a lookup service in peer-to-peer overlay networks. Many valuable applications have been recently built on top of several available DHTs. However, they function poorly when no direct IP connectivity is available to some nodes (e.g., located behind a NAT or firewall) or in the presence of overloaded or malicious nodes. In this paper, we propose a new method for DHT-based routing called cyclic routing. It generalizes existing single-hop look-ahead approach (also known as ldquoKnow thy neighbor´s neighborrdquo) and supports multipath routing. The method provides a systematic way for collecting stable and efficient overlay paths. Cyclic routing has the same theoretical dependability and efficiency upper bounds as basic DHT routing but it is more resilient when IP connectivity is limited or when the overlay suffers from overloaded nodes.