An Upper Bound to the Loss Probability in the Multiplexing of Jittered Flows

In the context of Diffserv networks some services should be characterized by end-to-end quantitative QoS guarantees. In order to provide such guarantees to single flows (or flow aggregates), the end-to-end analysis of delay and loss performance in a Diffserv domain is needed. The impact of jitter should be considered in the performance analysis at the successive nodes along the path of a flow (flow aggregate). Worst-case analysis is a solution to provide deterministic quantitative guarantees, at the price of very low efficiency. As an alternative this paper proposes a probabilistic approach, aimed at providing statistical quantitative guarantees and achieve higher efficiency. The proposed analytical approach is based on the insertion of a discarding device before the FIFO queue, called “dropper”. The purpose of the dropper is to avoid the analysis of the congestion at the burst level in the queue, allowing for the application of an analytical result derived for packet scale conflicts in the modulated ND/D/1 queue. Simulations are presented that validate the analytical bound. Finally numerical results are provided to evaluate the efficiency of the bound in an admission control scheme.