BBTopologicalLink Down

Down indicates that the SONET/SDH connection through the black box in at least one direction on a bidirectional link is degraded to the point of no longer passing traffic.

The aEnd/zEnd directionality for each topological link is determined by the API parameters when the black box is created.

The symptoms for BBTopologicalLink Down are as follows:

• LOS from downstream PTP connected to the BBTopologicalLink

• LOF from downstream PTP connected to the BBTopologicalLink

• RDI on the upstream PTP connected to the BBTopologicalLink

• AIS on the downstream PTP connected to the BBTopologicalLink