Summary: Inferring Link Weights using End­to­End Measurements
Ratul Mahajan Neil Spring David Wetherall Tom Anderson
University of Washington
Abstract---We describe a novel constraint­based approach
to approximate ISP link weights using only end­to­end mea­
surements. Common routing protocols such as OSPF and
IS­IS choose least­cost paths using link weights, so inferred
weights provide a simple, concise, and useful model of intra­
domain routing. Our approach extends router­level ISP
maps, which include only connectivity, with link weights
that are consistent with routing. Our inferred weights agree
well with observed routing: while our inferred weights fully
characterize the set of shortest paths between 84­99% of the
router­pairs, alternative models based on hop count and la­
tency do so for only 47­81% of the pairs.
I. INTRODUCTION
Over the past several years, Internet mapping technol­
ogy based on end­to­end measurements has matured to the
point where realistic router­level maps are now becoming
available [3, 6, 11, 19]. These maps are in turn being used

Source: Anderson, Richard - Department of Computer Science and Engineering, University of Washington at Seattle

Collections: Computer Technologies and Information Sciences