On the placement of Internet instrumentation

The IDMaps project aims to provide a distance map of the Internet from which relative distances between hosts on the Internet can be gauged. Many distributed systems and applications can benefit from such a distance map service, for example, a common method to improve user-perceived performance of the Internet is to place data and server mirrors closer to clients. When a client tries to access a mirrored server, which mirror should it access? With IDMaps, the closest mirror can be determined based on distance estimates between the client and the mirrors. In this paper we investigate both graph theoretic methods and ad hoc heuristics for instrumenting the Internet to obtain distance maps. We evaluate the efficacy of the resulting distance maps by comparing the determinations of the closest replica using known topologies against those obtained using the distance maps