Patent ID: 7680032
Filing Date: 2010-03-16
Classification: H04J,H04L

Abstract:
1. A method of allocating protection bandwidth in a mesh network having a first bi-directional ring comprised of a first plurality of nodes coupled by a first plurality of spans and a second bi-directional ring comprised of a second plurality of nodes coupled by a second plurality of spans, the first and second rings sharing a common section comprising at least two common nodes coupled by at least one span, the method comprising: in a normal operational mode for the first ring, routing working traffic on paths of the first ring with at least one path of the working traffic including the at least one span of the common section, wherein the first ring has a symmetrical arrangement of working and protect ports; responsive to detecting a defect along a first path of the first ring, performing a line switch in the first ring to redirect working traffic along another path of the first ring that excludes the defect in the first ring and which traverses the common section; in a normal operational mode for the second ring, routing working traffic on paths of the second ring with none of the working traffic traversing the at least one span of the common section, wherein the second ring has an asymmetrical arrangement of working and protect ports such that the second ring has at least one unconfigured working port that ignores or rejects a received switch command and does not perform a commanded span or ring switch; responsive to detecting a defect along a path of the second ring, performing a line switch to redirect working traffic along another path of the second ring that excludes the defect in the second ring and which traverses the common section and adjusting optical power of the common section to account for protection traffic of the second ring traversing the common section in the protection mode of the second ring; wherein the common section is provisioned such that it provides protection for both the first and second rings.