The Alarm light indicates whether the ONT has detected any issues or alarms. A steady red light indicates an alarm condition, such as a loss of power or a problem with the fiber-optic connection. If it is off, none of the photo eyes will be lit because there is no signal being sent. In this case, you have a bad transmitting photo eye the problem. DDM information - check whether the parameters are normal through the "show interfaces transceiver detail" command, if there is an alarm, it means that the optical module is faulty or the optical module does not match the optical interface type. If an alarm appears, it means that the optical module. As a key component of passive optical networks (PONs), the optical line terminal (OLT) must be correctly configured and operating reliably for the network to function. Issues with the OLT can impact services for many customers.
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