Abstract—Distance estimation and topological proximity in the Internet have recently emerged as important problems for many

Structured Overlay Networks provide a promising platform for high performance applications since they are scalable, fault-tolerant and self-managing. Structured overlays pro-vide lookup services that map keys to nodes that can be used as processing or storage resources. The lookups for a key may return inconsistent results. Consequently, it is nontrivial to provide consistent data services on the top of structured overlays that are built on key-based search. In this paper, we study the frequency of occurrence of incon-sistent lookups. We show that the effect of lookup incon-sistencies can be reduced by assigning responsibility of key intervals to nodes. We present our results as a trade-off between consistency and availability of keys. Further, since many distributed applications employ quorum techniques at their core, we analyze the probability that majority-based quorum techniques will function correctly in a structured overlay with inconsistent lookups. Our analysis shows that the probability of majority-based algorithms to function cor-rectly despite lookup inconsistencies is high. 1.