Effect of ingress buffering on self-similarity of optical burst traffic

Abstract

Recently, optical burst switching and aggregated optical packet switching have gained significant exposure as possible future mechanisms for routing aggregated IP traffic over all-optical core networks. However, the limited buffering capacity in all-optical networks presents a major challenge, as current IP traffic displays strong self-similar properties. Reducing the burst loss rate of such long-range dependent traffic can be costly requiring a significant increase in either the network bandwidth or the buffer size of optical cross connects. In this paper, we revisit the possibility of using buffers to reduce self-similarity before the traffic is routed onto the all-optical core. The aim of this paper is to increase the understanding of the effect of packet/burst aggregation on the self-similarity measure of the traffic. In particular, we implement a simple burst assembly mechanism with two parameters, the maximum burst length L and the maximum burst delay d, so that incoming traffic is smoothed with a guaranteed delay bound. Unlike previous works, we simulate the burst assembler using more realistic input traffic sources, and analyze the results using both R/S plot and discrete wavelet analysis methods. Our detailed results show that buffering indeed reduces traffic self-similarity (an area of research controversy) when parameters L and d are set appropriately.