The optical module is faulty or not securely installed. If the transmit optical power is abnormal, replace the. When the optical modules at both ends of the link work normally, the transmit optical power is within a certain range, which can be learned by checking the corresponding product datasheet or reading the module threshold on the switch. If the optical power is too high, it will cause signal distortion, packet loss, and even damage to the optical module. Optical Receive Power (RX): The most critical metric. This tells you how much light is making it through the fiber cable to your switch.