Parallel Simulation Techniques for Large Scale Networks

Simulation has always been an indispensable tool in the design and analysis of telecommuni cation networks Due to performance limitations of the majority of simulators usually network simulations have been done for rather small network models and for short time scales In con trast many di cult design problems facing today s network engineers concern the behavior of very large hierarchical multi hop networks carrying millions of multiprotocol ows over long time scales Examples include scalability and stability of routing protocols packet losses in core routers or long lasting transient behaviors due to observed self similarity of tra c patterns Simulation of such systems would greatly bene t from application of parallel computing tech nologies especially now that multiprocessor workstations and servers have become commonly available However parallel simulation has not yet been widely embraced by telecommuni cations community due to a number of di culties Based on our accumulated experiences in parallel network simulation projects we believe that parallel simulation technology has matured to the point that it is ready to be used in industrial practice of network simulation This article highlights recent work in parallel simulations of networks and its promises