Link performance monitoring is a common task required by different overlay networks. Current overlays typically let each node monitor links by itself, which is not scalable for large networks. Earlier improvement proposals either use a centralized approach or sacrifice measurement accuracy. This paper proposes
, a distributed overlay monitoring technique. Based on the proposed
concept, MONET enables peer cooperation so that each node performs a minimum amount of measurement but can deduce the performance of any link. It does not lose accuracy and adapts to IP-layer path dynamics. Theoretical analysis and simulation results, in terms of monitoring cost and querying overhead, are also discussed in this paper.