Analysis of prioritized scheduling of assured forwarding in DiffServ architectures

Assured service has been proposed within the differentiated services (DiffServ) model to provide relative service differentiation by attempting to allocate bandwidth to different users in a controlled way during periods of network congestion. In this paper, we analyze the assured service scheme by means of a priority queueing system with state-dependent service scheduling based on thresholds. We consider the case of two classes of priority, carry out a mathematical analysis and numerically obtain the average delay endured by packets in each priority class and the loss probability for each class. To quantify the gain obtained under our threshold-based priority scheme over static priority based schemes, we also study the priority scheduling and weighted fair queuing models, and compared our results with the ones obtained using these two models.