Methods of protection sharing for multi-protected optical demands in large-scale WDM mesh networks
View Patent ↗A method and system for identifying and, optionally, managing protection resource sharing opportunities, such as within a large-scale wavelength-division multiplexing (WDM) mesh network.
1. A method for distributing protection capacity within a mesh network, comprising:
determining, for at least one failure associated with at least one protected lightpath in the mesh network, a corresponding failed path;
determining a backup path capacity for the failed path;
assigning one or more links of the failed path to other lightpaths in the mesh network; and
storing data indicative of the backup path capacity in a network management system associated with the mesh network;
wherein each of said at least one protected lightpath is associated with an allowed number of failures determined to affect another lightpath.
2. The method of claim 1 , wherein said assigning is performed in accordance with at least one protection sharing mechanism selected in accordance with a management constraint.
3. The method of claim 1 , wherein said assigning is performed in accordance with at least one protection sharing mechanism selected in accordance with a service constraint.
4. The method of claim 1 , further comprising:
determining, for a set D of up to k-protected lightpaths, a primary link capacity C p ; and
storing data indicative of the primary link capacity C p .
5. The method of claim 4 , further comprising:
invoking a pre-processing heuristic to determine primary and backup path orders.
6. The method of claim 5 , wherein the pre-processing heuristic operates to iteratively process each lightpath d within the set D of up to k-protected lightpaths to determine for each lightpath d a respective path p associated with a smallest maximum link capacity.
7. The method of claim 4 , wherein a total backup link capacity for each lightpath d within the set D of up to k-protected lightpaths is determined using a nominal sharing mechanism.
8. The method of claim 4 , wherein the total backup link capacity for each lightpath d within the set D of up to k-protected lightpaths is determined using a protection release mechanism.
9. The method of claim 7 , wherein the total backup link capacity for each lightpath d within a set D of up to k-protected lightpaths is determined using one of a stratification mechanism and a nonstratification mechanism.
10. The method of claim 7 , wherein the total backup link capacity for each lightpath d within the set D of up to k-protected lightpaths is determined using a working reuse mechanism.
11. The method of claim 7 , wherein the total backup link capacity for each lightpath d within the set D of up to k-protected lightpaths is determined using a failover ordering mechanism.
12. A method for distributing protection capacity within a mesh network, comprising:
determining, for at least one failure associated with at least one protected lightpath in the mesh network, a corresponding failed path;
determining a backup path capacity for the failed path;
assigning one or more links of the failed path to other lightpaths in the mesh network; and
storing data indicative of the backup path capacity in a network management system associated with the mesh network;
wherein a lightpath d being processed is associated with an allowed number of failures of the lightpath d determined to affect another lightpath.
13. The method of claim 12 , wherein the allowed number of failures is indicated by a corresponding count of failures where the affected lightpath is a member of a same protection tier.
14. The method of claim 13 , wherein the protection tier is defined in terms of at least one of a service type, a geographic region and a service provider.
15. The method of claim 13 , wherein the allowed number of failures is indicated by a corresponding count of failures where the affected lightpath is a member of a different protection tier, said protection tier being defined using at least one of a service type, a geographic region and a service provider.
16. The method of claim 1 , wherein data indicative of an overall backup capacity C is adapted to manage a provisioned network experiencing one or more link failures.
17. The method of claim 1 , wherein an overall backup capacity C is updated according to a component-wise maximum value C with an independent backup capacity C b .
18. A computer program product wherein computer instructions, when executed by a processor in a telecom network element, adapt the operation of the telecom network element to provide a method for identifying protection capacity sharing opportunities for a mesh network topology, comprising:
determining, for at least one failure associated with at least one protected lightpath in the mesh network, a corresponding failed path;
determining a backup path capacity for the failed path;
assigning one or more links of the failed path to other lightpaths in the mesh network; and
storing data indicative of the backup path capacity in a network management system associated with the mesh network;
wherein each of said at least one protected lightpath is associated with an allowed number of failures determined to affect another lightpath.
19. The computer program product of claim 18 , wherein said telecom network element comprises a network management system (NMS).
20. A network management system (NMS) including a computer for executing instructions which adapt the operation of the computer to perform a method for distributing protection capacity within a mesh network, the method comprising:
determining, for at least one failure associated with at least one protected lightpath in the mesh network, a corresponding failed path;
determining a backup path capacity for the failed path;
assigning one or more links of the failed path to other lightpaths in the mesh network; and
storing data indicative of the backup path capacity in a network management system associated with the mesh network;
wherein each of said at least one protected lightpath is associated with an allowed number of failures determined to affect another lightpath.
21. A method for distributing protection capacity within a mesh network, comprising:
identifying primary and protection capacity associated with each of a plurality of protected lightpaths within the mesh network;
determining, for each of a plurality of k-element failures, a corresponding protection capacity for recovering from the k-element failure;
determining protection capacity sharing opportunities according to each of a plurality of protection sharing mechanisms; and
adapting protection capacity allocations in response to the determined protection sharing opportunities wherein a lightpath d being processed is associated with a counter, a value of the counter being changed if a failure of the lightpath d is determined to affect another lightpath.
22. The method of claim 21 , wherein the counter is initially set to k.
23. The method of claim 22 , wherein the counter is decremented only if the affected lightpath is a member of a same protection tier.
24. The method of claim 23 , wherein the protection tier is defined in terms of a service type, geographic region and/or service provider.
25. The method of claim 23 , wherein the counter is decremented only if the affected lightpath is a member of a different protection tier.
26. The method of claim 21 , wherein the protection sharing mechanisms are selected in accordance with at least one of a management constraint and a service constraint.
27. The method of claim 21 , further comprising:
determining, for a set D of up to k-protected lightpaths, a primary link capacity C p ; and
storing data indicative of the primary link capacity C p .
28. The method of claim 27 , further comprising:
invoking a pre-processing heuristic to determine primary and backup path orders.
29. The method of claim 28 , wherein the pre-processing heuristic operates to iteratively process each lightpath d within the set D of up to k-protected lightpaths to determine for each lightpath d a respective path p associated with a smallest maximum link capacity.
30. The method of claim 21 , wherein a total backup link capacity for each lightpath d within the set D of up to k-protected lightpaths is determined using at least one of a nominal sharing mechanism, a protection release mechanism, a stratification mechanism, a nonstratification mechanism, a working reuse mechanism and a failover ordering mechanism.
31. The method of claim 21 , wherein a lightpath d being processed is associated with an allowed failures counter set initially to k, the allowed failures counter being decremented if a failure of the lightpath d is determined to affect another lightpath.
32. The method of claim 21 , wherein the allowed_failures counter is decremented only if the affected lightpath is a member of a same protection tier, said protection tier being defined using at least one of a service type, a geographic region and a service provider.
33. The method of claim 21 , wherein the allowed failures counter is decremented only if the affected lightpath is a member of a different protection tier, said protection tier being defined using at least one of a service type, a geographic region and a service provider.
34. The method of claim 1 , wherein said assigned links comprise an allocation of protection capacity, the method further comprising:
adapting protection capacity allocations associated with protected lightpaths in response to a determined overall backup capacity C of the mesh network.
35. The method of claim 34 , wherein said overall backup capacity C of the mesh network is determined by processing each of a plurality of protected lightpaths within the mesh network.