OTUk_LOM is an alarm indicating that the frame alignment signal (FAS) is abnormal.

OTUk_LOM (Loss of Multiframe) alarm is generated when frame alignment is lost; however, the statement that it occurs when the Frame Alignment Signal (FAS) is Out of Frame (OOF) for three consecutive milliseconds is false. The actual time threshold differs slightly according to standards and vendor implementations. HCIP-Transmission clarifies these alarm thresholds and conditions to ensure precise timing in fault detection, avoiding false alarms while providing timely notifications for network maintenance.