Protection scheme for a communications network under multiple failures

• US 20040218525A1
• Filed: 04/29/2003
• Published: 11/04/2004
• Est. Priority Date: 04/29/2003
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Elie-Dit-Cosaque, David, Ali, Maher
• Granted Patent: US 7,352,703 B2
• Time in Patent Office: Days
• US Class Current: 370/223
• CPC Class Codes: H04L 41/0631 using root cause analysis; using analysis of correlation between notifications, alarms or events based on decision criteria, e.g. hierarchy, tree or time analysis
• CPC Class Codes: H04L 41/064 involving time analysis
• CPC Class Codes: H04L 41/0659 by isolating or reconfiguring faulty entities
• CPC Class Codes: H04L 41/083 for increasing network speed
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/22 Alternate routing
• CPC Class Codes: H04L 45/28 using route fault recovery

Abstract

A system and method for implementing a shared protection scheme under a scenario of multiple failures in an optical network. In one embodiment of the invention, a working path between an ingress node and an egress node is computed responsive to a connection request received in the network. One or more backup paths are computed between the ingress and egress nodes, which are activatable upon a failure condition associated with the working path or the backup paths. The backup paths may be based on link and/or node disjointedness, as well as resource-based cost constraints.

Claims

1. A method for providing protection in a communications network including a plurality of nodes coupled by communication links, comprising:

responsive to a connection request received by an ingress node, computing a working path between said ingress node and an egress node;

computing a plurality of backup paths between said ingress and egress nodes, each of said backup paths being activatable upon a failure condition associated with at least one of said working path and one of said backup paths; and

transmitting messages to nodes spanning said working path and backup paths for setting up said working path and backup paths.

2. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said working path between said ingress node and said egress node is computed based on a Shortest Path First (SPF) algorithm.

3. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths are computed recursively until a predetermined number of backup paths is reached with respect to said working path.

4. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are completely link-disjointed with respect to one another.

5. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are partially link-disjointed with respect to one another.

6. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are completely node-disjointed with respect to one another.

7. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are partially node-disjointed with respect to one another.

8. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are completely link-disjointed with respect to said working path.

9. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are partially link-disjointed with respect to said working path.

10. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are completely node-disjointed with respect to said working path.

11. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said backup paths comprise paths that are partially node-disjointed with respect to said working path.

12. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said working path and said backup paths are computed based on a cost parameter associated with said communication links, said cost parameter operating to penalize communication links that disallow sharing of paths.

13. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said working path and said backup paths are computed based on a prior-use cost parameter associated with said communication links, said prior-use cost parameter operating to penalize communication links that are already used.

14. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said failure condition comprises a quality degradation event.

15. The method for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 1, wherein said failure condition is correlated with other failure conditions in said communications network.

16. A system for providing protection in a communications network including a plurality of nodes coupled by communication links, comprising:

means for computing a working path between a ingress node and an egress node responsive to a connection request received by said ingress node;

means for computing a plurality of backup paths between said ingress and egress nodes, each of said backup paths being activatable upon a failure condition associated with at least one of said working path and one of said backup paths; and

means for transmitting messages to nodes spanning said working path and backup paths for setting up said working path and backup paths.

17. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said working path between said ingress node and said egress node is computed based on a Shortest Path First (SPF) algorithm.

18. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths are computed recursively until a predetermined number of backup paths is reached with respect to said working path.

19. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are completely link-disjointed with respect to one another.

20. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are partially link-disjointed with respect to one another.

21. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are completely node-disjointed with respect to one another.

22. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are partially node-disjointed with respect to one another.

23. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are completely link-disjointed with respect to said working path.

24. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are partially link-disjointed with respect to said working path.

25. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are completely node-disjointed with respect to said working path.

26. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said failure condition comprises a quality degradation event.

27. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said failure condition is correlated with other failure conditions in said communications network.

28. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said backup paths comprise paths that are partially node-disjointed with respect to said working path.

29. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said working path and said backup paths are computed based on a cost parameter associated with said communication links, said cost parameter operating to penalize communication links that disallow sharing of paths.

30. The system for providing protection in a communications network including a plurality of nodes coupled by communication links as set forth in claim 16, wherein said working path and said backup paths are computed based on a prior-use cost parameter associated with said communication links, said prior-use cost parameter operating to penalize communication links that are already used.

31. A network element disposed as an ingress node in an optical network formed from a plurality of nodes that are inter-coupled via optical communication links, said ingress node including a processor-accessible medium having a plurality of instructions for carrying out network operations, comprising:

instructions for computing a working path between said ingress node and an egress node, said instructions operating responsive to a connection request received by said ingress node;

instructions for computing a plurality of backup paths between said ingress and egress nodes, each of said backup paths being activatable upon a failure condition associated with at least one of said working path and one of said backup paths; and

instructions for transmitting messages to nodes spanning said working path and backup paths for setting up said working path and backup paths.

32. The network element as set forth in claim 31, wherein said instructions for computing said working path include instructions for determining a working path between said ingress node and said egress node based on a shortest path first algorithm.

33. The network element as set forth in claim 31, wherein said instructions for computing said backup paths include instructions operable to determine multiple backup paths using a methodology in which said backup paths are completely link-disjointed with respect to one another.

34. The network element as set forth in claim 31, wherein said instructions for computing said backup paths include instructions operable to determine multiple backup paths using a methodology in which said backup paths are completely node-disjointed with respect to one another but for said ingress and egress nodes.

35. The network element as set forth in claim 31, wherein said instructions for computing said backup paths include instructions operable to determine multiple backup paths using a methodology in which said backup paths are partially node-disjointed with respect to one another but for said ingress and egress nodes.

36. The network element as set forth in claim 31, wherein said instructions for computing said backup paths include instructions operable to determine multiple backup paths using a methodology in which said backup paths are partially link-disjointed with respect to one another.

37. The network element as set forth in claim 31, wherein said instructions for computing said backup paths and said working path include instructions operable to calculate paths based on a cost parameter associated with said communication links, said cost parameter operating to penalize communication links that disallow sharing of paths.

38. The network element as set forth in claim 31, wherein said instructions for computing said backup paths and said working path include instructions operable to calculate paths based on a prior-use cost parameter associated with said communication links, said prior-use cost parameter operating to penalize communication links that are already used.