Fast Simulation of a Voice-Data Multiplexer

The determination of packet loss rates in multiplexers is an important problem that has received much attention in the literature. This paper considers the problem of estimating, via simulation, extremely low packet loss rates in a voice-data multiplexer. The multiplexer gives priority to voice packets, unless the data queue length exceeds a threshold. To eeciently simulate such low loss rates requires the proper use of importance sampling. In this paper we describe an importance sampling technique that is guaranteed to provide an exponential decrease in variance over standard simulation. This importance sampling technique has two phases, with a diierent importance sampling strategy in each phase. Experimental results are presented that demonstrate the eeectiveness of this approach.