PCoord : A Decentralized Network Coordinate System for Internet Distance Prediction

Several recently emerged Internet services make use of application-level or overlay networks. Examples of such services include overlay multicast, structured peer-topeer lookup services, and peer-to-peer file sharing. Many of these services could benefit from enabling participating end hosts to estimate their relative network locations within the overlay. In this thesis, we present PCoord, a peer-to-peer network coordinate system for overlay topology discovery and distance prediction. The goal of PCoord is to allow participating peer nodes in an overlay network to collaboratively construct an accurate geometric model of the overlay network topology in a completely decentralized peer-to-peer fashion. We evaluate the PCoord approach through extensive simulations using both real network measurements and simulated topologies. Our simulation results indicate that PCoord can embed hosts in a low dimensional Euclidean model with a small median prediction error. Thesis Supervisor: Steven Lerman Title: Class of 1922 Professor of Civil & Environmental Engineering