Using a tandem queue model we evaluate the local “endogenous”
(= internal) queueing delay in single server and multiserver queueing networks. The new concept of the apparent overall upstream queueing delay(as perceived by the downstream network) allows us to analyze the distribution of this local queue by interpolating between the distributions of
the tandem queue (generated by a concentration tree) and the isolated
G/G/squeue. The interpolation coefficients depend on the proportion of
“premature departures”, typically interfering in the upstream stage and
leaving the considered path without being offered to the considered local
queue. On the other hand, local “exogenous” arrivals (from outside the
network) require the introduction of the “interference delay” concept.
Finally, in the case of single server queueing networks, we stress the need
to extend the capacities of the buffers, by considering the “worst case”
scenario and by using an “equivalent tandem queue” model.
