Sometimes on Huawei OLT you can see Dying gasp Alarm (0x2e11a00b).
Since they often occur, most likely they can be seen by running the commands:
display alarm active alarmid 0x2e11a00b display alarm history alarmid 0x2e11a00b
I will give an example:
ALARM 531377 FAULT MINOR 0x2e11a00b SERVICE QUALITY 2017-12-06 08:19:27+02:00
ALARM NAME : The dying-gasp of GPON ONTi (DGi) is generated
SRVEFF : SA
PARAMETERS : FrameID: 0, SlotID: 5, PortID: 6, ONT ID: 32, Equipment ID:
DESCRIPTION : The ONT is power off
CAUSE : The power supply of the ONT is abnormal
ADVICE : Check the power supply of the ONT and ensure that the power
supply works in the normal state
These alarms occur when power is lost or the power cord is removed from the ONT, at this moment ONT manages to send the Dying gasp message to the OLT.
Dying gasp is also used on many other devices, for example, to correctly terminate the connection.