QoS Differentiation in Asynchronous Bufferless Optical Packet Switched Networks

Optical Packet/Burst Switched networks (OPS/OBS) have emerged as promising all-optical network architectures for future core networks due to good resource utilization and the ability to handle high line speeds in a cost-efficient way. Regarding these networks, Quality of Service (QoS) differentiation should be provided in order to give sufficient QoS to real-time applications, and to utilize network resources optimally. In this paper, we present three fundamental different QoS differentiation schemes suitable for asynchronous bufferless OPS. We present analytical models and derive explicit results for the packet loss rates. We then present a general evaluation framework followed by a comparison study of the considered QoS differentiation schemes. Simulation and analytical results show that QoS differentiation schemes based on preemption have better performance than drop based and access-restriction based QoS differentiation schemes.