Finding a dense-core in jellyfish graphs

Mira Gonen, Dana Ron, Udi Weinsberg, Avishai Wool

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

2 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 densecore is a very important practical task when analyzing the Internet's topology. In this work we introduce a randomized sublinear algorithm that finds a densecore 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. 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
Title of host publicationAlgorithms and Models for the Web-Graph - 5th International Workshop, WAW 2007, Proceedings
Number of pages12
StatePublished - 2007
Externally publishedYes
Event5th Workshop on Algorithms and Models for the Web-Graph, WAW 2007 - San Diego, CA, United States
Duration: 11 Dec 200712 Dec 2007

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume4863 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference5th Workshop on Algorithms and Models for the Web-Graph, WAW 2007
Country/TerritoryUnited States
CitySan Diego, CA


  • Time Complexity
  • Edge Density
  • Sparse Graph
  • Border Gateway Protocol


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

Cite this