TR-05-4.pdf

``Location awareness in unstructured peer-to-peer systems",

Yunhao Liu, Li Xiao, Xiaomei Liu, Lionel M. Ni, and Xiaodong Zhang

IEEE Transactions on Parallel and Distributed Systems, Vol. 16, No. 2, 
February 2005, pp. 163-174. 

Abstract

Peer-to-Peer (P2P) computing has emerged as a popular model aiming at further 
utilizing Internet information and resources. However, the mechanism of peers 
randomly choosing logical neighbors without any knowledge about underlying 
physical topology can cause a serious topology mismatch between the P2P 
overlay network and the physical underlying network. The topology mismatch 
problem brings great stress in the Internet infrastructure. It greatly limits 
the performance gain from various search or routing techniques. Meanwhile, 
due to the inefficient overlay topology, the flooding-based search mechanisms 
cause a large volume of unnecessary traffic. Aiming at alleviating the 
mismatching problem and reducing the unnecessary traffic, we propose a 
location-aware topology matching (LTM) technique. LTM builds an efficient 
overlay by disconnecting slow connections and choosing physically closer 
nodes as logical neighbors while still retaining the search scope and 
reducing response time for queries. LTM is scalable and completely 
distributed in the sense that it does not require any global knowledge of 
the whole overlay network. The effectiveness of LTM is demonstrated through 
simulation studies.