Abstract— When multiple paths are available between communicating hosts, application quality can be improved by switching among them to always use the best one. The key to such an approach is the availability of diverse paths, i.e., paths with uncorrelated performance. A promising approach for implementing the necessary path diversity is to leverage the capabilities of peer-to-peer systems. Peer-to-peer systems are attractive not only because their many participating nodes can act as relays for others, and therefore offer a large number of different alternate paths, but also because their distributed operation can facilitate the deployment of the required functionality. However, these advantages come at a cost, as the sheer number of alternate path choices they offer creates its own challenge. In particular, because not all choices are equally good, it is necessary to develop mechanisms for easily and rapidly identifying relay nodes that yield good alternate paths. This paper is abou...