Multiclass wavelength reservation in optical burst switched WDM networks

This paper proposes a preemptive multiclass wavelength reservation protocol to provide differentiated service for optical burst switched (OBS) networks, without requiring buffers at the WDM layer. Unlike existing approaches, such as JET QoS, which suffer from implementation constraints and which may degrade to classless schemes, our mechanism is robust and supports an incremental deployment of QoS support and cooperates well with other "best-effort" reservation mechanisms like Horizon and the original JET. We maintain a usage profile for each class at the router, and implement a preemptive wavelength reservation algorithm to ensure QoS. We also conduct simulations to evaluate performance. The result shows that our approach performs best in terms of lower blocking probability and higher resource utilization, making our approach an excellent QoS mechanism for OBS networks.