| Optical networking is a promising solution to support the ever-increasing Internet traffic. This thesis aims to investigate the important issues of topology design, resource sharing, differentiated service provision, flow control as well as the methodology for performance evaluation of optical networks.;Next, we design a feedback-based OBS controller by assigning an exponential distribution to the burst assembly intervals. The loss rate of a flow can be controlled by adjusting the assembly timer. Based on this, we design and study a generic OBS controller for different assembly algorithms and signaling protocols that do not need global network information nor affect the network throughput. Some efficient predictor and adjuster models are proposed to implement the control process. Performance evaluation shows that this method is superior to other ordinary schemes based on the rate-adjustment method. Some critical issues on the system design and parameter settings are also investigated and discussed.;Finally, we revisit the fundamental star topology to develop an overlaid-star topological variation and address various implementation issues in such architecture. We model the node connections as an asymmetrical multiconnection three-stage Clos network, and propose a network flow model to solve the routing, wavelength assignment and time slot assignment problems under the time-division-multiplexing operation. We demonstrate via simulations that this overlaid-star topology can support flexible QoS provisioning that we are currently studying.;In summary, our work provides a technologically feasible solution to provide required QoS for future high-speed networks using available optical technologies.;We first build two analytical models in order to approximate the loss rate of an Optical Burst Switching (OBS) node more accurately than the traditional burst-based methods. Through the analysis of interacting bursts at the core nodes, we compare the loss ratio of different flows under various assembly parameters. We then propose a DiffSery scheme by adjusting the assembly parameters for different optical bursts. This scheme is suitable for a distributed OBS network without any requirement on centralized information or operation. |
