An analysis of the congestion effects of link failures in wide area networks

Abstract

The results of a study to determine the effects of link failures on network performance are presented. The network studied is a virtual-circuit-based packet-switched wide area network. A generic queuing framework is developed to study the effect of failures, and the subsequent traffic restoration, on network performance. In general, the congestion resulting after a failure is a transient phenomenon. Hence, a numerical-method-based nonstationary queuing analysis is conducted in order to quantify the effects of failures in terms of the transient behavior of queue lengths and packet loss probabilities. A bounding relationship is developed whereby a network node can determine whether or not congestion will occur as the result of traffic restoration after a failure.<>