Cut Saturation for p -cycle Design

1. Cut Saturation for p-cycle Design Khalid Al-Snaie Electronics Dept., College of Technology Riyadh, Saudi Arabia Dale R. Thompson* Department of Computer Science & Computer Engineering (CSCE) University of Arkansas

2. Ring vs. Mesh

3. Two Enemies of Fiber

4. Four-fiber Bidirectional Line-Switched Ring (BLSR), no failure

5. Four-fiber BLSR, span switching

6. Four-fiber BLSR, ring switching

7. Wavelength-Division Multiplexing Red Green Blue

8. Wavelength Path #1 S1 D1 2 S2 D3 1 D2 S3 1

9. Wavelength Path #2 S1 D1 2 S2 D3 1 D2 S3 2

10. Virtual Wavelength Path (VWP) S1 D1 2 S2 D3 1 D2 S3 2

11. One preconfigured protection cycle (p-cycle), no failures

12. One p-cycle, on-cycle span failure

13. One p-cycle, straddling span failure

14. SCP vs JCP in p-cycles • Spare capacity placement (SCP) • Route demand using shortest paths • Apply capacity algorithm to find set of p-cycles that minimize spare capacity cost • Joint capacity placement (JCP) • Apply capacity algorithm to find working routes and set of p-cycles that minimize spare capacity cost.

15. Cut Saturation

16. p-cycle Cut Saturation (PCUT) Load topology and traffic demand. do { Route traffic with JCP or with shortest path algorithm if using SCP. Sort spans by load in descending order. Remove spans one at a time until the network separates into two disconnected components N1 and N2. Add a new span between one of the lowest degree nodes in N1 and one of the lowest degree nodes in N2. Replace deleted spans. Find p-cycles with SCP or JCP. Calculate spare-to-working capacity ratio. } while (spare-to-working capacity ratio is greater than a threshold)

17. NSF Network

18. Add span #1 (N0 to N9)

19. Add span #2 (N7 to N14)

20. Add span #3 (N15 to N24)

21. Add span #4 (N10 to N23)

22. Final Answer (N0 to N9, N7 to N14, N15 to N24, N10 to N23)

23. Spare-to-working capacity

24. Contact Information Dale R. Thompson, P.E., Ph.D. Department of Computer Science and Computer Engineering University of Arkansas 311 Engineering Hall Fayetteville, Arkansas 72701 Phone: +1 (479) 575-5090 FAX: +1 (479) 575-5339 E-mail: d.r.thompson@ieee.org WWW: http://csce.uark.edu/~drt/