An object oriented approach to simulating large communication networks

The complexity of modern communication systems in terms of the number of entities, their interaction, and the resulting dynamics make an analytical study often impossible. Their analysis may require the experimental study through simulation. A simulation environment for large network infrastructures must be carefully designed since the simulator performance becomes a critical issue as the model complexity increases. Our effort to design such a simulation environment was driven by the need to evaluate heuristic routing strategies for very large communication networks through experimental studies. We have chosen to employ the object oriented paradigm in our approach. In addition, critical issues such as the choice of pre-scheduling versus post-scheduling and the generation of a priori service time had to be considered during the design. In this paper we give an overview of the design of an object oriented simulation tool for large networks and discuss some of the issues that are pertinent to the design of a discrete event simulator for the study of complex communication infrastructures.