Modeling and Performance Evaluation of Multistage Interconnection Networks with Nonuniform Traffic Pattern* Youngsong Mun 1 and Hyunseung Choo 2 1 School of Computing, Soongsil University, Seoul, KOREA mun@computing. ssu.ac.kr 2 School of Electrical and Computer Engineering Sungkyunkwan University, Suwon 440-746, KOREA choo@ece.skku.ac.kr Abstract Even though there have been a number of studies about modeling MINs, almost all of them are for studying the MINs under uniform traffic which cannot reflect the realistic traffic pattern. In this paper, we propose an analytical method to evaluate the performance of ATM switch based on MINs under non- uniform traffic. Simulation results show that the proposed model is effective for predicting the performance of ATM switch under realistic nonuniform traffic. Also it shows that the detrimental effect of hot spot traffic on the network per- formance turns out to get more significant as the switch size increases. 1 Introduction Since ATM has been adopted as a standard for broadband ISDN, many research ef- forts have been focused on the design of the next generation switching systems for ATM. The three main approaches employed for the design of an ATM switch are shared medium, shared memory, and space-division architecture [1]. In all these de- signs, the limitation on the switching size is the primary constraint in the implementa- tion. To make a larger size ATM switch, thus, more than one system is interconnected in a multistage configuration [2]. Multistage interconnection networks (MINs) [3] constructed by connecting simple switching elements (SEs) in several stages have been recognized as an efficient inter- connection structure for parallel computer systems and communication systems. There have been a number of studies investigating the performance of MINs in the literature [4-8]. However, almost all of these previous works are for studying the MINs under the uniform traffic pattern. Nonuniform traffic reflects the realistic traffic pattern of currently deployed integrated service network where a wide range of bandwidths needs to be accommodated. Therefore, the performance of the MINs under nonuni- form traffic must be studied for obtaining efficient switch-based system. Even though * This work was supported by Brain Korea 21 Project. P.M.A. Sloot et al. (Eds.): ICCS 2002, LNCS 2331, pp. 1061-1070, 2002. © Springer-Verlag Berlin Heidelberg 2002