PP-MESS-SIM - A FLEXIBLE AND EXTENSIBLE SIMULATOR FOR EVALUATING MULTICOMPUTER NETWORKS

This paper presents pp-mess-sim, an object-oriented discrete-event sim ulation environment for evaluating interconnection networks in message -passing systems. The simulator provides a toolbox of various network topologies, communication workloads, routing-switching algorithms, and router models. By carefully defining the boundaries between these mod ules, pp-mess-sim creates a flexible and extensible environment for ev aluating different aspects of network design. The simulator models eme rging multicomputer networks that can support multiple routing and swi tching schemes simultaneously; pp-mess-sim achieves this flexibility b y associating routing-switching policies, traffic patterns, and perfor mance metrics with collections of packets, instead of the underlying r outer model. Besides providing a general framework for evaluating rout er architectures, pp-mess-sim includes a cycle-level model of the PRC, a programmable router for point-to-point distributed systems. The PRC model captures low-level implementation details, while another high-l evel model facilitates experimentation with general router design issu es. Sample simulation experiments capitalize on this flexibility to co mpare network architectures under various application workloads.