Performance evaluation of an optical transparent packet switch

This paper presents first results concerning the performance evaluation of an optical transparent packet switch that solves contention using optical delay lines. In the switch under study, delay lines are grouped in several sets, as the first stage of the switch. Each input port has access to a few of these delay lines, and each set of delay lines has access to each output port. Non-FIFO output buffers are thus emulated using scheduling on a small number of delay lines with non-consecutive delays. Under simplifying assumptions, analytical models are derived, and validated by simulation. These models provide efficient bounds for estimating packet loss probability, under the assumption of regular, balanced input traffic. It is shown that the proposed switch architecture achieves a good performance in terms of packet loss, with a number of delay lines significantly smaller than the one currently used in other architectures.