The Desgin and Implementation of the libcage NATProblem Free DHT Library

Abstract

Distributed hash tables (DHTs) which provide scalable key-value store and lookup sevices are methods to construct Peer-to-Peer(P2P) networks. However, existing algorithms of DHTs don't consider problems caused by NATs. We must consider NATs which are very serious hindrance for P2P networks when designing and implementing P2P network applications, but typical algorithms and implementations don't consider NATs sufficiently. Thus, we design a DHT which works well in environments involving NATs and implement a reference code as library to prove our proposals. Since the source code is distrubuted under BSD license on the Internet, anyone can use and modify it freely.