A comparison of push-out policies in an ATM multiplexer

The authors investigate the impact of choosing different push-out policies (first-in-first-drop, last-in-first-drop, and random) on the loss performance at an ATM (Asynchronous Transfer Mode) multiplexer. They evaluate the effect of these policies on the loss probability and on the distribution of consecutive loss. Although differences were found for the loss probability, they do not imply a decrease of an order of magnitude. When the low-priority loss probability is high, the last-in-first-drop plays a major role in the decrease of the number of consecutive losses and, depending on the coding, may have a decisive impact on the quality of real-time signal reconstruction at the receiver. Choosing a policy between first-in-first-drop and last-in-first-drop is a trade-off between improving quality of service requirements: high-priority loss probability and low-priority average number of consecutive loss. Random offers intermediate performance quality between the aforementioned policies