This is the unique name identifier for an OSC (optical supervisory channel) interface, the dedicated low-rate channel used for management and telemetry alongside the main traffic-bearing wavelengths. Operators reference this name to identify which supervisory channel instance they're looking at when checking DCN or management connectivity between two optical sites. For example, alarms tied to "OSC-1-1-1" tell the admin the management link to a specific amplifier site is affected, not the traffic wavelengths themselves.