Influence of real-time queue capacity on system contents in DiffServ's expedited forwarding per-hop-behavior
Thomas Demoor, Joris Walraevens, Dieter Fiems, Stijn De Vuyst, Herwig Bruneel · Journal of Industrial and Management Optimization · 2010
This paper studies a single-server non-preemptive priority queuewith two traffic classes in order to model Expedited ForwardingPer-Hop Behavior in the Differentiated Services (DiffServ)architecture. Generally, queueing models assume infinite queuecapacity but in a DiffServ router the capacity for high prioritytraffic is typically small to prevent this traffic frommonopolizing the output link and hence causing starvation oflow-priority traffic. The presented model takes the exact (finite)high-priority queue capacity into account. Analytical formulas forthe system content of each class are determined as well as thehigh-priority packet loss ratio. For each class, service of apacket takes a (different) general independent distribution. Theissues this causes are resolved by using spectral decomposition.Numerical examples indicate the considerable impact of the finitecapacity on system performance.