We are configuring a new lambda (10G) between two nodes, we have tributary (TDX) and line (ND2) boards on each node but when we finish the configuration,
appears OTU2_DEG and ODU_PM_DEG alarms on both sides and we can not run a test with the SmartBits.
We started the troubleshooting and we made the followings action:
1. We checked by T2000 the input optical power on boards (TDX and ND2) on each node but this value was on its range according to manuals.
2. We measure the input optical power on each board by an OPM but this was well.
3. We changed the optical fibers in the direction of transmission but these were not the problem.
4. We made outloop on each TDX port in order to test the port with the SmartBits and this test worked.
5. We discard that boards was faulty because the alarms appeared on both nodes.
After all this tests, we started to check the "WDM configuration" in order to confirm that all configurations were the same:
* We checked the TDX on both sides but its configuration was the same.
* We checked the ND2 on both sides and we found that in one node the "FEC mode" was configured in "FEC" and in the other node was configured in "AFEC",
so, we changed "FEC mode" to "FEC" on both side and the alarms were cleared, then, we ran the test with the SmartBits and it worked.
According to manuals, this alarms can be caused for the followings issues:
* The input optical power of the board is abnormal.
* The fiber of the transmission line is abnormal.
* The optical interface at the local end is faulty.
* The board that reports the alarm is faulty.
Always, besides the causes which are described by the manual, you have to check in the "WDM Configuration" on each board and confirm that all configuration is
ok and is the same on each node, the most important parameters are the followings:
* FEC Mode
* Line Rate
* Service Mode
* Service Type
* Port Mapping