CORNet: An OBS metro ring network with QoS support and fairness control

The rapid evolution of networks has been driven by new advances in enabling technologies and the explosive growth of Internet traffic. Optical Burst Switching (OBS) is not only cost-effective, but also provides high throughput, high bandwidth utilization, and low transmission latency. These benefits make OBS a viable solution for next-generation Metro Area Networks (MANs) in which the traffic models will be changed more dramatically than in today's networks. This paper employs Wavelength Division Multiplexing (WDM) technology to construct a loss-free OBS metro ring architecture designated as the Collision-free Optic-burst Ring Network (CORNet). The proposed architecture ensures a collision-free transmission of data bursts, while retaining the advantage of the statistical multiplexing provided by conventional OBS networks. A novel distributed Medium Access Control (MAC) protocol to integrate the support of differentiated service and fairness access in CORNet is presented. The proposed Quality of Service (QoS) provisioning mechanism adopts a bandwidth-reservation approach which combines real-time transmission establishment and termination routines. Furthermore, a credit-based fairness control scheme is designed to guarantee the transmission fairness of best-effort traffic. Simulation results are presented to demonstrate that the proposed CORNet system provides good performance for real-time traffic while simultaneously providing significant performance improvements for best-effort traffic.