This OID stores the low alarm threshold for incoming optical signal power in decibels per milliwatt (dBm), with values typically ranging from -40 to +8.2 dBm. Network engineers configure this to trigger critical alerts when a fiber-optic receiver detects power so weak the signal becomes unreliable. For example, a threshold of -30 dBm means an alarm fires when the received signal drops below that level, indicating a failing transmitter or damaged fiber.