Prioritized Buffer Management in Photonic Packet Switches for Synchronously Arriving Fixed-length Packets

We investigate a photonic packet switch architecture that enables a high node throughput and provides priority services. We describe PBSO (partial buffer sharing with overwriting) method that allows control of an optical fiber-delay-line buffer by prioritized buffer management under conditions of synchronous arrival of fixed length optical packets at a packet switch. The PBSO method is based on a single queue and its complexity isO p , where p is the number of priority classes. We first present photonic buffer architectures which can support the PBSO method. We also develop an analytical method for PBSO where p . Through analysis and simulation results, we show that PBSO improves the packet loss probability in each priority class more than the existing PBS (partial buffer sharing) does, and that it can be actually applied to prioritized buffer management of an optical buffer. PBSO is especially effective when the arrival rate of higher priority class packets is much lower than that of lower priority class packets. In that case, PBSO dramatically improves the performance of higher priority class packets while the degradation in the performance of lower priority class packets is small. In other words, in PBSO, a larger number of higher priority class packets can be accepted at a given packet loss probability than in PBS or non-priority methods.