Network Performance of Broadband Hosts: Measurements & Implications

With the rapid growth in the popularity of and the research interest in peer-to-peer (P2P) systems, an interesting question is what the quality of network connectivity between peers in the “real world ” is and what impli-cations this has for applications. In this paper, we describe an effort called PeerMetric to directly measure P2P network performance from the vantage point of broadband-connected residential hosts. Our measurements indi-cate significant asymmetry in bandwidth, with median downstream and up-stream available bandwidths of 900 Kbps and 212 Kbps, respectively. We argue that the availability of last-hop bandwidth is more important than the traditional consideration of locality for overlay multicast over broad-band hosts. We also considered the peer selection problem and found that a simple delay-vector based approach is effective for finding proximate peers (in terms of latency). However, P2P latency turns out to be a poor predictor of P2P TCP throughput, which may be the metric of interest for applica-tions such as file sharing. I