INTEGRATED PERFORMANCE MODELS FOR DISTRIBUTED PROCESSING IN COMPUTER COMMUNICATION NETWORKS.

Abstract

The authors analyze large-scale closed queuing network (QN) models that are used for the performance analysis of computer communication networks (CCNs). The computer systems are interconnected by a wide-area network. Users accessing local/remote computers are affected by the contention (queuing delays) at the computer systems and the communication subnet. The computational cost of analyzing such models increases exponentially with the number of user classes (chains), even when the QN is tractable (product-form). In fact, the submodels of the integrated model are generally not product form. Two approximate solution methods are proposed, both of which use decomposition and iterative techniques to exploit the structure of the QN model such that computational cost is proportional to the number of chains. The accuracy of the solution methods is validated against each other and simulation. The model is used to study the effect that channel capacity assignments, window sizes for congestion control, and routing have on system performance.