There was a metro100 with 2*STM-1 and 16*E1 interface ready for commissioning. the NE softver was 5.42.03.12, and using T2000V2R3.
after creating service, all ports shows T-ALOS and major LFA alarm.
cables installation were not ready so I desided to make a softloop on interface as a test.
T-ALOS disappeared after that but still LFA was existed.
Alarm Data Description
Framed E1 frame asynchronous
Related board FP1D
Indicator status The MIN indicator on the front panel flashes and the mapping E1
indicator is yellow.
Cause Three consecutive wrong framing signals are received.
1- when this configuration are to change to "UF.E1" we will loose CRC4 checking of the frame in SDH. so "I.421" is a reliable protocol to use.
2- in troubleshouting handling, it is more important to check the external cause, before internal.