Pharos: A Decentralized and Hierarchical Network Coordinate System for Internet Distance Prediction

Network coordinates (NC) system is an efficient mechanism for Internet distance prediction with limited measurements. In this paper, we identify the intrinsical cause for the inadequate accuracy of the simulation based NC algorithms. We then propose Pharos, a fully decentralized and hierarchical scheme, to remedy this problem. Pharos leverages multiple coordinate sets at different distance scales, with the right scale being chosen for prediction each time. We evaluate the performance of Pharos system with the King data set and latency data from PlanetLab, and compare it with the representative NC system, Vivaldi. The experimental results show that Pharos outperforms Vivaldi much without adding any significant overhead.