Performance management in NetWare and Windows NT networks using protocol simulation

The paper describes protocol simulation and its application in performance modeling and analysis. Windows NT and NetWare subnets of the School of Engineering at Widener University were considered as the problem domain. The protocol stacks analyzed include IPX/SPX, TCP/IP, NetBEUI AppleTalk. Analysis was conducted on 1.2 GB of data gathered daily over a period of two months by a network monitor. Over 30 traffic models have been built for these protocols. Identification of different types of protocol traffic in association with source and destination was effected through customized packet filtering. Data thus obtained were transferred to a spreadsheet. Frequency histograms were created using a random sampling technique from data files obtained. The traffic models built, were statistically verified using various goodness of fit tests. Application sources were scheduled by iteration time or by received messages, and sessions were simulated based on observed traffic. Original network predictions made have been verified by both the simulation output and empirical observations.