A. The Cisco ONS 15454 has lost its Data Communications Channel (DCC). The Cisco ONS 15454 uses the DCC on the SONET section layer (SDCC) to communicate network management information. The possible causes are: • One or both ends of the fiber span are not in service. • The far end of the fiber span does not have a DCC termination provisioned. • There is signal failure on the fiber span (must be accompanied by Loss of Signal (LOS) alarms), broken or dirty connectors, loss budget out of parameters, improper termination, or a broken fiber. • High Bit Error Rates (BERs) or a BER threshold for signal degrade alarm can sometimes cause this alarm.