This paper proposes a general methodology for building a soft ware tool to aid in the design and performance modeling of local computer networks. At the core of the modeling approach lies a distributed view of the network consisting of independently modeled network functional components—protocols, nodes, and resources. The network components communicate through model defined or user provided interfaces. As a consequence, the effect of network changes, component deletions, or addi tions are localized and the network model can be easily altered to highlight certain components while reducing others as re quired in different design phases. The result is that long simula tion runs of a large and fully detailed model are replaced by shorter runs of several smaller "function oriented" network models. The inherent partitioning of the system model into relatively independent functional units makes it also a poten tial candidate for a distributed simulation implementation.
The given methodology is exemplified with an actual implemen tation of an Ethernet* based system configuring tool. The methodology can also be applied to other distributed systems to build efficient modular simulator programs.
Complete paper available from Simulation journal.