Finding a dense-core in Jellyfish graphs

Mira Gonen, Dana Ron, Udi Weinsberg, Avishai Wool

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


The connectivity of the Internet crucially depends on the relationships between thousands of Autonomous Systems (ASes) that exchange routing information using the Border Gateway Protocol (BGP). These relationships can be modeled as a graph, called the AS-graph, in which the vertices model the ASes, and the edges model the peering arrangements between the ASes. Based on topological studies, it is widely believed that the Internet graph contains a central dense-core: Informally, this is a small set of high-degree, tightly interconnected ASes that participate in a large fraction of end-to-end routes. Finding this dense-core is a very important practical task when analyzing the Internet's topology. In this work we introduce a randomized sublinear algorithm that finds a dense-core of the AS-graph. We mathematically prove the correctness of our algorithm, bound the density of the core it returns, and analyze its running time. We also implemented our algorithm and tested it on real AS-graph data and on real undirected version of WWW network data. Our results show that the core discovered by our algorithm is nearly identical to the cores found by existing algorithms - at a fraction of the running time.

Original languageEnglish
Pages (from-to)2831-2841
Number of pages11
JournalComputer Networks
Issue number15
StatePublished - 23 Oct 2008
Externally publishedYes


  • AS-graph
  • Dense-core
  • Sublinear algorithm


Dive into the research topics of 'Finding a dense-core in Jellyfish graphs'. Together they form a unique fingerprint.

Cite this