A simulation study of an ATM service multiplexer in the North Carolina Information Highway

This paper presents some simulation results of our study of an output-buffered ATM service multiplexer (ATM-SMX) in the North Carolina Information Highway WAN. There are three types of traffic input to the multiplexer: 1) bursty; 2) continuous-bit-rate (CBR); and 3) variable-bit-rate (VBR) traffic. These mixed sources contend for transmission on the high-speed output link of the multiplexer. In our simulator, there are N_s identical bursty sources each modelled as a Markov modulated Bernoulli process (MMBP); a number (N_C) of CBR sources modelled as periodic arrivals with constant packet length; and VBR sources represented by N_V periodic arrivals where the number of ATM cells per frame follows a negative binomial distribution. The influence of two queueing disciplines-priority-first-in-first-out (P-FIFO) and push-out and threshold (P & T) scheduling-are explored. Our results show how the delay and cell loss probability of the ATM-SMX are affected by the mixed traffic and two scheduling policies