A crucial factor for real-time (interactive) services is the end-to-end delay experienced by the application. The contribution resulting from the queuing delay induced by the network nodes is the most difficult to assess. First, it is a stochastic quantity which should be aggregated over many (possibly different) network nodes. Secondly, the queuing delay in a single node stems from two different mechanisms: one related to interference with other interactive flows and one related to interference with the ubiquitous best-effort data flows. Earlier work assessed these two components separately, leading to a ‘worst case’ result. This paper models both components and develops formulas to calculate exact results for the end-to-end queuing delay. Results are shown indicating an improvement up to 45% over the worst-case method. The formulae developed in this paper are expected to be useful in network dimensioning, in setting network performance requirements and in admission control mechan...
Robert E. Kooij, Olav N. Østerbø, J.