Simulating Computer Networks using Clusters of PCs

Simulation has become the dominant technique for evaluating the performance of many products before real hardware is produced. In computer networks, this is particularly true, and can avoid expensive hardware and software development. Using simulation it is possible to explore different protocols and design options, under different loads, long before the design is frozen. However, such simulations can be time consuming, especially if a large number of scenarios are to be considered. In this paper, we show how it is possible to perform distributed execution of a network simulation written for the OpNet package. This is performed using a distributed computing tool called Clustor. Very high efficiency has been experienced on a variety of workstation clusters. A case study is presented in which a real network protocol is evaluated using OpNet and Clustor.