Performance of ATM switches with priority traffic and back-pressure function

Abstract

An ATM(Asynchronous Transfer Mode) technology realizes B-ISDN (Broadband Integrated Services Digital Network) by multiplexing various kinds of multimedia information. ATM network must be designed to accommodate all types of traffics with their various charateristics and QoS(Quality of Service) demands. The QoS of ATM connection is mainly described by two parameters: transfer delay of cell and cell loss probability. In this thesis, we analyze cell delay for ATM switches with back-pressure function for two types of traffics: delay sensitive traffic and delay insensitive traffic. The switch has input and output buffers. The cell loss is prohibited by back-pressure mechanism. This switch system is assumed to operate synchronously, and arrivals of two types of traffics are assumed to be two independent Bernoulli processes. The total delay through the switch is the sum of input delay, HOL delay and output delay. We analyze the HOL delay using the virtual queue method which is popular method for performance analysis of switches. For two types of traffics, we obtain the mean delay for three switch operating schemes, and give numerical examples.