Modeling and efficient distributed simulation of multistage interconnection networks

Multistage interconnection networks are used in a number of application areas such as parallel computers and high-speed communication systems. As the performance of these systems lies on an efficient design of the interconnection network, a thorough analysis of the network´s performance is important. Mathematical analysis so far provides inadequate results and simulation analysis using a uniprocessor usually requires extremely long run time to evaluate large networks. This paper addresses the use of parallel simulation techniques to speedup the simulation of multistage interconnection networks. The conventional null-message approach for resolving deadlock problem in conservative simulation may cause livelock if lookahead is not guaranteed. We propose a deadlock/livelock free scheme using null messages, but without the guaranteed lookahead, to coordinate the simulation, and different partitioning techniques for mapping of the simulation program onto multicomputers. A flushing mechanism is also used to resolve the null-message explosion problem. Our analysis shows that the proposed flushing mechanism effectively reduces the number of null messages from exponential to linear