Optical cross-connect device, optical transmission system, and optical transmission line connection error detection method

An optical cross-connect apparatus comprising:

• a monitoring control unit including one or more processors, the monitoring control unit connected to an OpS (Operation System) that is configured to perform control related to operation and maintenance of a plurality of optical cross-connect apparatuses that are connected to an optical network;
• a relay-side optical input/output unit, including one or more processors, configured to output an LOS (Loss of Signal) alert to the monitoring control unit when an optical signal that has received after being relayed by a relay apparatus that relays an optical signal transmitted from another optical cross-connect apparatus has insufficient optical power;
• a DSP (Digital Signal Processor) unit configured to perform processing to change a modulation mode of an optical signal received from the relay-side optical input/output unit, and output an LOF (Loss of Frame) alert to the monitoring control unit when the modulation mode of the optical signal relayed by the relay apparatus is non-conforming;
• and
• a framer unit, including one or more processors, configured to perform processing to change a frame mode and an FEC (Forward Error Correction) of the optical signal processed by the DSP unit, output an LOF alert to the monitoring control unit when the frame mode and the FEC of the optical signal are detected as being non-conforming, and acquire unique transmission source information of another optical cross-connect apparatus included in the optical signal and notifies the monitoring control unit of the transmission source information when the frame mode and the FEC are detected as being conforming,
• wherein the monitoring control unit is configured to store, in a storage unit, a management table in which pieces of information regarding the modulation mode, the FEC, and the frame mode are associated with each other, sequentially change the modulation mode, the FEC, and the frame mode according to the management table upon the LOS alert or the LOF alert being input thereto, and, upon successfully receiving an appropriate optical signal according to the change, acquire transmission source information included in the optical signal, and detects an occurrence of erroneous connection of an optical transmission line of the relay apparatus when the acquired transmission source information indicates an optical cross-connect apparatus that is a transmission source different from an original transmission source.