1. TRLabs Confidential SmartBoard Presentation May 29 May 29 th 2003, SmartBoard Presentation NFOEC-2003Sep 11, 2003 Ring Mining to p-Cycles as a Target Architecture Riding Demand Growth into network efficiency Speaker : Adil Kodian (Ph.D. Candidate, TRLabs, University of Alberta) - Co Authors - Dr. Wayne Grover (TRLabs, University of Alberta) Jim Slevinsky, David Moore (Technology Strategy group, TELUS Communications, Edmonton)

2. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Presentation Overview What is ring-mining? What are p-cycles ? How to migrate from an existing ring-based network ? What about protection from span failures ? Results for migration planning on a real-world metro network.

3. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. What is ring-mining? What are p-cycles ?

4. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Introduction Rings – Disadvantages All ring-types, require 100% redundancy. Network growth is awkward. Stranded capacity effects trigger whole ring additions. Multi Ring network design is very complex. Service path routing is ring-like – increases path length Rings – Advantages Simple structure, easily understood by many. Fast restoration – ( ~50 ms for UPSRs). Management complexity and switching fabric complexity less. Ideal future network - Simple structure Fast restoration Low Redundancy

5. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. What is Ring-Mining ? -REVIEW A GOOD SOLUTION IN TERMS OF CAPACITY EFFICIENCY. LIMITED SALVAGE POTENTIAL FOR HIGH SPEED INTERFACES. STILL REQUIRES PURCHASE OF CROSS CONNECTS AT THE NODES TO PERFORM MESH SWITCHING. NO RE-USE OF EXISTING NODAL EQUIPMENT EXCEPT AT DEGREE 2 NODES. “Ring Mining to Span Restorable Mesh:” (as originally defined) Convert ring capacity to Span Restorable mesh capacity by conversion and/or re-use of transmission equipment convert operation to mesh break open the rings

6. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. What are p-cycles ? –REVIEW Sample p-Cycle loopback On-Cycle Failure Break-in Straddling Span failure

7. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Why Migrate to p-Cycles ? p-Cycles are cycle structures like rings – so migration is an easier leap. p-Cycles are pre-configured protection mechanisms like rings – giving ring like restoration times. p-Cycle based networks have mesh like redundancy. p-Cycles allow working paths to follow shortest paths.

8. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. How to migrate from an existing ring-based network ?

9. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Technology for interfacing straddling spans with ring nodes Local Add/Drop E SWITCH CORE Add Drop Multiplexer W Additional Add/Drop N E SWITCH CORE Straddling Span Interface Unit W W Long reach fiber Line Rate Interfaces Short reach fiber Straddling span Explicit re-termination of protection fiber N Working Fiber Protection Fiber

10. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Migration to p-Cycles – a logical illustration Legacy Network Situation Two Coupled rings with one span elimination (C-F). Ring Capacity Saturation due to Matched Node Setup. Spare/Working Line Capacity ratio = 15/15 = 100%, 15 ADMs used. Drop and Continue Penalty in two working spans for transit node survivability. C.O. “A” C.O. “B” D E F G H I J K L M C

11. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Convert Ring operation to p-Cycles Salvage 2 ADMs. Add SSIUs to two ADMs. Node survivability is maintained, without drop and continue penalty. Spare/Working Line Capacity ratio = 13/15 ~ 87%. Exhaust relieved by elimination of drop and continue. C.O. “A” C.O. “B” C D E F G H I J K M L

12. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Re-use eliminated span to support further demand growth C.O. “A” C.O. “B” D E F G H I J K L M C Exhaust from growth forecast in region of E,D,C,G. Re-instate “eliminated span” into the network. Spare/Working Line Capacity ratio = 13/17 ~ 76%. Add 2 more SSIUs at C and F. Return several working routes to shortest path and relieve capacity.

13. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Add Capacity to the network to support growth C.O. “A” C.O. “B” D F G H I J L M C K Imminent exhaust from new demands or growth in region of M,L,K. Lease/Acquire new span M-J. Spare/Working Line Capacity ratio = 13/19 ~ 68%. Add 2 SSIUs at M and J, and release capacity by re-routing some demands. Capacity addition and new equipment purchase is only for new demand. E

14. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. What about protection from span failures ?

15. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. How does the network react in case of a span cut ? 4 p-cycles cover entire network Sample p-cycle ring-mining solution Network View

16. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Ring-Mining to p-cycles : p-cycle solution set (Test Network) A single p-cycle protecting a single working unit through an on-cycle span. Network View

17. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Ring-Mining to p-cycles : p-cycle solution set (Test Network) A single p-cycle protecting a single working unit through an on-cycle span. BLSR LIKE LOOP BACK Network View

18. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Ring-Mining to p-cycles : p-cycle solution set (Test Network) A single p-cycle protecting a single working unit through a straddling span. Network View

19. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Ring-Mining to p-cycles : p-cycle solution set (Test Network) A single p-cycle protecting a single working unit through a straddling span. Network View

20. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Results for migration planning on a real-world metro network.

21. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Results for Test Networks : Comparing p-cycles with mesh UNIFORM DEMAND MULTIPLIER WITHOUT ANY CAPACITY ADDITION CAPACITY ADDITION REQUIRED FOR SPECIFIC VALUE OF MULTIPLIER Capacity Design Studies on 17 test ring networks (from Ph.D. thesis on multi-ring network design). Uniform Demand Multiplier

22. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. TELUS METRO NETWORK PLANNING STUDIES BASED ON p-CYCLES(1) Metro Network Characteristics 46 Total Transport Systems ( Ring and Point to Point ) 1 OC-48 Point to Point Link 6 OC-48 BLSR Rings 5 OC-48 UPSR Rings 12 OC-12 BLSR Rings 22 OC-12 Point to Point Links. Serves a modern metro city of more than a million people – one of Canada’s biggest cities. 43 Physical Spans and 36 Nodes. (nodes and spans overlap in geographical map) Logical Network Diagram

23. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Traffic Characteristics Demand Volume – 683 STS-1 Service Paths (O-D pairs). Installed Fibre Capacity across all spans – 6792 STS-1 channels (1 hop). Ring network is built incrementally, so 80-90% of demands do not transit rings – suboptimal capacity utilization – 57.3% of all working capacity in this network. TELUS METRO NETWORK PLANNING STUDIES BASED ON p-CYCLES(2)

24. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Results of planning study(1) Condition 1 : Only existing capacity can be re-used –Research Question : How much more demand can be served simply by re- arranging the existing working routes, and re-assigning spare capacity to operate as p-Cycles? –Answer : Ring-Mining without any capacity additions allows every demand in the network to grow atleast 1.5 times ! Condition 2: Additional capacity can be added to existing spans, only after span exhaust, and at additional cost. –Research Question : what is the capacity addition versus demand growth profile? –Answer: M M = Uniform Demand Growth Multiplier

25. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Results of planning study(2) Condition 3: Only existing capacity can be re-used, and existing working routing cannot be changed. –Research Question : How much more demand can be served simply by re- assigning spare capacity ? New demands can be routed shortest path. –Answer : Ring-Mining without any capacity additions allows every demand in the network to grow atleast 1.33 times ! Condition 4: Additional capacity can be added to existing spans, after exhaust, and at additional cost. Existing working routing cannot be changed. –Research Question : what is the capacity addition versus demand growth profile? How much does excess capacity is required? –Answer: M M = Uniform Demand Growth Multiplier

26. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Summary Migrating from Rings to p-cycles has similar capacity efficiency as compared to migrating to a Span restorable Mesh network. p-Cycles can be implemented on ADM based networks. Capacity addition and equipment purchase may be only when and where new demand materializes. ( No need to buy redundant capacity) A gradual migration path exists from rings to p-cycles. This solution is independent of type of transport network technology. The STS-1 p-cycle concept can be completely replaced by a wavelength p-cycle. Protection switching mechanism ensures fast restoration. It does not require too much extra capacity to preserve existing working routing through the migration

27. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. QUESTIONS ? Main References: 1.M. Clouqueur, W. D. Grover, D. Leung, O. Shai, “Mining the rings: strategies for ring-to-mesh evolution,” Proc. Design of Reliable Communication Networks (DRCN 2001), Budapest, Hungary, October 2001, pp.113-120. 2.W.D. Grover, D. Stamatelakis, “Cycle-oriented distributed pre-configuration: ring- like speed with mesh-like capacity for self-planning network restoration,” in Proc. IEEE International Conf. Commun. (ICC '98), Atlanta, June 8-11 pp. 537-543.

28. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Backup Slides –1: SSIU Access through extra traffic interface. Local Add/Drop E SWITCH CORE Add Drop Multiplexer W Additional Add/Drop N E SWITCH CORE Straddling Span Interface Unit W W Long reach fiber Line Rate Interfaces Straddling span SSIU uses extra traffic feature to access protection fiber of ring ADM N Working Fiber Protection Fiber

29. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Backup Slides –2: SSIU Access through Switch fabric. Local Add/Drop E SWITCH CORE Add Drop Multiplexer W Additional Add/Drop N E SWITCH CORE Straddling Span Interface Unit W W Long reach fiber Line Rate Interfaces Straddling spans SSIU uses switching fabric to interface straddling spans on per Lambda basis N Working Fiber Protection Fiber DCS SWITCH CORE Backplane Connection

30. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Backup Slides- 3 – Zoomed-in view of Nodes in protection switch A single p-cycle protecting a single working unit through a straddling span. Site 1 Site 2 Zoom into this area

31. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Ring-Mining to p-cycles : p-cycle solution set (Test Network) A single p-cycle protecting a single working unit through a straddling span. Site 1 Site 2 Zoom into this area Zoomed-in View of the Nodal Devices at Sites 1 & 2 Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S ADM SSIU ADM SSIU ADMs with SSIUs to interface with straddling spans Straddling Span

32. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Zoomed-in View of the Nodal Devices at Sites 1 & 2 Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S ADM SSIU ADM SSIU ADMs with SSIUs to interface with straddling spans Straddling Span

33. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Normal Working routing through on-cycle spans only Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S ADM SSIU ADM SSIU SSIU provides continuity of protection signal, but otherwise is passive in this scenario Straddling Span

34. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Normal Working routing through straddling spans Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S ADM SSIU ADM SSIU SSIUs use the Extra Traffic capability of the ADMs to handle working routing through straddling spans. – ADMS need to do nothing in this scenario. Straddling Span

35. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Failure on Straddling Span Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S Universal Fiber Locator ADM SSIU ADM SSIU Only the SSIUs detect this failure. It is transparent to existing ring ADMs. Straddling Span

36. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Failure on Straddling Span – Protection Routing Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S Universal Fiber Locator ADM SSIU ADM SSIU SSIUs handle all the switching, and is transparent to the Ring ADM. Straddling Span

37. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Failure on Straddling Span – Alternate Protection Routing Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 2 SWITCH CORE N S Local Add/Drop N W E Additional Local Add/Drop W E ALARM Site 1 SWITCH CORE N S Universal Fiber Locator ADM SSIU ADM SSIU SSIUs handle all the switching, and is transparent to the Ring ADM. Straddling Span

38. Ring-Mining to p-Cycles as a target architecture : Riding Demand Growth into Network Efficiency. A.Kodian, W.Grover, (TRLabs) J.Slevinsky, D.Moore (TELUS Communications) NFOEC 2003 – Sept 11, 2003, Session B9. Backup Slides – 4 –Dark Fiber Question Additional Research Question : If there exists a lot of dark fibre in the ground – and fibre capacity additions are almost free, is it not better to just cap and grow as opposed to ring-mining ? Answer: Even if fibre is free – additional opex and capex costs involved in leasing new facilities. It is advantageous to use existing resources more efficiently. Uses Existing Resources more efficiently