Analytical methods to evaluate the performance of computer and communication networks for commercial business

The universal executing computer and communication networks for commercial business (CCNCB) are larger computer and communication systems that have one or a number of host computer systems with main frames providing information processing services. Terminals of such computer systems include workstations, personal computers, commercial POS servers and various subsystems. The purpose of this paper is to give some efficient analytical methods to evaluate the system performance of the CCNCB. The analysis is based on the method of decomposition where the whole computer center system is divided into two subnetworks at CPU (central processing unit). The first subnetwork (call Net1) has a number of servers (I/O devices) and the second subnetwork (call Net2) has a server (CPU). We can model these two subnetworks as the generalized M/G/m and M/G/1 queueing systems, respectively. Net1 has higher priority than Net2 and the service process of Net2 corresponds to the one of Net1. We derive the average queue length and the utilization in such a CCNCB system involving an arbitrary but finite number of terminals which may have different job types. The analysis results for the system are tested by simulation. It is demonstrated that this analysis method is particularly useful, simple and accurate in treating the CCNCB systems.