Enabling ALS on an Interface

The constraints on ALS are as follows:

Only optical interfaces support ALS. Electrical interfaces do not support ALS.
When optical interfaces transmit services unidirectionally, they do not support ALS.
When the GPON optical module is used on the optical port, the ALS function is not supported. In addition, after the GPON optical module is inserted, all the ALS-related commands configured on this interface are cleared.

Run system-view
The system view is displayed.
Run interface interface-type interface-number
The interface view is displayed.
Run als enable
ALS is enabled on an interface.

By default, ALS is disabled on an interface.