After the OptiX OSN 3500 is upgraded on the entire network, the interface board EFT8 connected with the EFS0 board incurs failure of alarm reversal on several ports. These ports report ETH_LOS alarms. The version is upgraded to OptiX OSN 3500 V100R006C01B01dSPC004.
Set alarm reversal again for the ports incurring alarms.
Alarm reversal of the EFS0 board is set to automatic mode before the upgrade. When the board is upgraded, it performs a warm reset and causes disappearance of all port alarms. If the alarms disappear for three minutes, the NE software considers they have disappeared and then cancels alarm reversal. Board reset generally ends within three minutes, and thus settings of alarm reversal are reserved. However, the EFS0 board takes a long time, generally more than three minutes, to finish reset. In this case, alarm reversal is cancelled and ETH_LOS alarms occur on the ports.
It is recommended to check the NEs for alarm reversal before upgrade. This avoids that LOS alarms are considered as service interruption after upgrade.