Systems and methods for path protection switching due to client protection switching

An apparatus, disposed in a node in a network, to avoid sympathetic switches in path switching protection due to client protection switching in Optical Transport Network (OTN), the apparatus comprising:

• circuitry adapted to monitor a drop side Tandem Connection Monitoring (TCM) entity and a line side TCM entity for a connection, wherein the drop side TCM is provisioned between a drop port of the node and a second drop port of a corresponding node, and wherein the line side TCM entity is provisioned between a plurality of line ports of the node and a second plurality of line ports of the corresponding node;
• circuitry adapted to cause, responsive to detection of defects in both the drop side TCM entity and the line side TCM entity on a working line, path protection switching of the working line;
• and
• circuitry adapted to cause, responsive to detection of defects only in the drop side TCM entity, path protection switching of the working line responsive to persistence of the defects for a time which is later than when both the drop side TCM entity and the line side TCM entity both have defects, a time which is later than a time required to avoid sympathetic switching, and a time that is less than a line protection switching time.

A node in a network adapted to avoid sympathetic switches in path switching protection due to client protection switching in Optical Transport Network (OTN), the node comprising:

• a plurality of ports communicatively coupled to a corresponding node;
• and
• a controller communicatively coupled to the plurality of ports and configured to
• monitor a drop side Tandem Connection Monitoring (TCM) entity and a line side TCM entity for a connection, wherein the drop side TCM is provisioned between a drop port of the node and a second drop port of a corresponding node, and wherein the line side TCM entity is provisioned between a plurality of line ports of the node and a second plurality of line ports of the corresponding node,
• responsive to detection of defects in both the drop side TCM entity and the line side TCM entity on a working line, cause path protection switching of the working line, and
• responsive to detecting detection of only in the drop side TCM entity, cause path protection switching of the working line responsive to the defects persisting for a time which is later than when both the drop side TCM entity and the line side TCM entity both have defects, a time which is later than a time required to avoid sympathetic switching, and a time that is less than a line protection switching time.