A tool for local area network modeling and analysis

Abstract

Predicting the performance of local area networks (LAN) is a difficult task. Existing analytical models are often too restrictive to apply to cases of interest. The results from previous studies are often difficult to extrapolate to other cases. Individual simulation models for local area networks have been developed in the past. Still, translating the description of the network under study between these models is not straightforward. A general LAN analysis system (GLAS) has been developed to address the performance issues in a common environment. This system models carrier sense multiple areas with collision detection (CSMA/CD), token ring, token bus, fiber distributed data interface (FDDI), networks using the standards defined by IEEE. Also, the logical link control protocol related to these standards is modeled, as are the priority mechanisms. Arbitrary topology and node traffic is allowed. A menu driven interface provides a convenient mechanism for the description of the LAN under study. New variance reduction techniques are included to increase the efficiency of the simulation model. Simple analytical models are included in GLAS to provide estimates of network performance when appropriate.