Performance Analysis of Queueing Networks with Blocking

Queueing network models have been widely applied for performance modeling and analysis of computer networks. Queueing network models with finite capacity queues and blocking (QNB) allow representing and analyzing systems with finite resources and population constraints. Different protocols can be defined to deal with finite capacity resources and they can be modeled in queueing networks with blocking by various blocking types or mechanisms. Modeling heterogeneous networks having different blocking protocols leads to heterogeneous QNB where the service centers may have different blocking types. QNB are difficult to analyze, except for the special class of product-form networks. Most of the analytical methods proposed in literature provide an approximate solution with a limited computational cost. This tutorial introduces queueing network models with finite capacity queues and various types of blocking. We discuss the main solution techniques for their exact and approximate analysis to derive network performance indices. We present and compare the solution methods for open and closed networks to identify the criteria for the appropriate selection of a solution method. We provide some application examples of this class of models to computer and communication networks.