An Overview of Some Network Modeling, Simulation & Performance Analysis Tools - Computers and Communications, 1997. Proceedings., Second IEEE Symposium on

This paper is an overview of more than forty of the leading tools being used in the field of network performance analysis, modeling and simulation. The purpose of this paper is to inform potential users of trends in the industry by providing an overview of some of the capabilities of each tool. With unique knowledge of the tools available and a solid background in mathematical modeling and networking architecture, it is possible to utilize some of these tools to dramatically shorten the time span involved in providing useful network architectural solutions, cost reduction and optimization of network resources. Tools Overview: An evaluation of most of the tools has been conducted. A brief description follows : 1 .Q+: This tool was developed at AT&T Bell Labs and was thefirst of its kind for the 80's which in fact led to the development of some external tools that share some of its central philosophy. It is based upon the use of queuing theory and simulation. Even though it is not very user friendly, it is a powerful engine requiring experienced modeling personnel. Considering the fact that its graphics have not kept up with the pace of commercial tools, user friendly interfaces, it does not present itself as an easily understandable tool for the average user even though some of its features are quite impressive. This tool has good long-term potential and continues to evolve albeit slowly. In its present form it can be used as a back-end for developing simulations of sub-components of customers' extensive networks since the front-end graphics have not yet been developed sufficiently. It is possible to do a variety of simulations using the queueing theory paradigm with this tool if modeling personnel with a strong academic background are available. 2.ATOMS: This is a statistical tool for performing multiple Qf runs for what-if studies and also uses the famous SAS statistical engine to enhance the statistical output of Q+. 3.PAT: This is an analytical performance analysis tool from Bell Labs and could be used to cross-check certain components of a simulation with mathematical formulas. It is an analytic tool for examining the performance of a distributed processing system or an intelligent network. It ocmbines both queueing network and activity network modeling concepts in that both probabilistic branching as well as parallel branching are allowed in describing the message flows of a call. PAT is completely data driven. PAT is used for single dimensional inversion applications. 4.MyPAL: This is another analytical performance analysis tool based upon the theory of transforms in queuing theory and is used again for further cross-checks of performance analysis simulations. It uses an approximation technique defined by the Widder Laplace transform inversion formula for inverting the Laplace transform. It does single dimensional transform inversion. 5.QNA: This is a queuing network analyzer analytical tool. It has been in use at Bell Labs for many years and interfaces with Q+. It is used for obtaining analytical approximations to open queuing networks. 6.PANACEA: This is yet another analytical performance analysis tool used for solving closed queuing networks problems and interfaces to Q+. 7.42 (Q squared): This is a new analytical performance tool that has been developed at AT&T Labs which is supposed to be the 'mother of all analytical tools'. It solves not only steady state but transient and time 0-8186-7852-6/97 $10.00