Critical load and congestion instabilities in scale-free networks

¹ The Abdus Salam International Centre for Theoretical Physics P.O. Box 586, 34100 Trieste, Italy
² Departamento de Física Teórica, Universidad de Zaragoza - Zaragoza 50009, Spain
³ Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya Campus Nord, Mòdul B4 - 08034 Barcelona, Spain
⁴ Department of Physics, University of Notre Dame - 225 Nieuwland Science Hall Notre Dame, IN 46556, USA
⁵ Laboratoire de Physique Théorique (UMR du CNRS 8627), Bâtiment 210 Université de Paris-Sud - 91405 Orsay Cedex, France

Corresponding author: yamir@ictp.trieste.it

Received: 27 November 2002
Accepted: 14 February 2003

Abstract

We study the tolerance to congestion failures in communication networks with scale-free topology. The traffic load carried by each damaged element in the network must be partly or totally redistributed among the remaining elements. Overloaded elements might fail on their turn, triggering the occurrence of failure cascades able to isolate large parts of the network. We find a critical traffic load above which the probability of massive traffic congestions destroying the network communication capabilities is finite.