A preemptive differentiation scheme for absolute loss guarantees in OBS networks

Abstract

The absolute QoS model is a promising approach to offering Quality of Service in OBS networks. It requires core nodes to offer absolute loss guarantees to burst flows. It then divides a required edge-to-edge loss probability by end applications into several small loss probabilities and allocate them to the intermediate core nodes. In this paper, we address the issue of providing per-node absolute loss guarantees in this QoS model and propose a preemptive differentiation scheme for that purpose. The scheme helps make the task of admission control easier and extend the loss guarantees to individual flows even though the differentiation is done at class level. The proposed scheme is analysed numerically and evaluated through simulation to show that it achieves the required objectives.