Cell blocking probabilities of the SAR sublayer function block in an ATM switch

Abstract

We consider a design problem for the segmentation and reassembly(SAR) sublayer with a shared buffer in an asynchronous transfer mode(ATM) switch. An ATM switch consists of a number of switching modules for reliability and maintenance. Like service traffics, control messages from each module are also segmented into cells of a fixed size, transmitted to the destination modules, and reassembled at each destination. These functions are controlled by the SAR sublayer function block under a stringent performance requirement of cell blocking probabilities, $10^{-9}-10^{-12}$. We first model the function block as a tandem queue model with an infinite buffer to approximate the blocking probabilities. For more realistic analysis, we develop a simulation model. To simulate rare events of blocking, we use the rare event simulation technique based on the generalized extreme value theory.