1. On The Deflection Routing in QoS Supported Optical Burst-Switched Network Ching-Fang Hsu, Te-Lung Liu, and Nen-Fu Huang Dep. of CS, NTHU, Taiwan, ROC. ICC 2002

2. The Deflection Routing The objective is to provide an alternative to resolve contentions for the same output link other than pure buffering. It may be implemented with or without output buffers. In just-enough-time-based OBS networks, optical buffers are necessary to prevent a burst from overtaking its control packet.

3. Share-per-port Optical Switch Architecture

4. Share-per-node Optical Switch Architecture

5. FDL Buffer Design

6. FDL Reservation Failure and Deflection Routing

7. Solutions to The Insufficient Offset-time Problem Extra offset time Delayed at previous hops Delayed at congested node Delayed at next hop

8. Solutions to The Insufficient Offset-time Problem (continued)

10. Queuing Model Overall loss probability γ 1, γ 0d, γ 0n, represent the mean arrival rate of class 1, deflected bursts of class 0 and non-deflected bursts bursts of class0 respectively, and γ n= γ 1 + γ 0d.

11. Numerical Result: Blocking Probability vs. Traffic Load

12. Numerical Result: Blocking Probability vs. Arrival Rate

13. Numerical Result: Blocking Probability vs. Class 1 Traffic Ratio

14. Numerical Result: Blocking Probability vs. Extra Offset Time of Class 1

15. Conclusion If deflection routing is enabled, optical buffers are necessary to solve the insufficient offset time problem. Buffering alleviation can be achieved by lengthening offset time just like high-priority traffic in the prioritized scheme. Deflection routing improves performances of both classed and whole network significantly.