An unusual Loss in a single DWDM Channel
Hi ,
Dear Community , today I have a case related of a loss in a single DWDM channel .
Description
-We have a DWDM network consists of OSN 6800 equipment which still work in FOADM mode ( uses M40 & D40 ) for Mux & Demux , We had an alarm of (IN PWR LOW ) in the LSX board (IN port ) .
Steps of Troubleshooting
- As all other channels passing the same path were in normal optical power values , so we started inspecting the fiber connection between the LSX board to the D40 board , We cleaned the fibers heads and checked them , but they were all ok .
-After making sure of fiber connection , we used OSA ( Optical Spectrum Analyzer ) to check the power value of the channel starting from first receiving point , to make sure whether the problem is from the source NE or from the receive NE .
-Starting from the Mon in the OAU amplifier then the Mon of the D40 the signal was in the perfect value until it get out of the D40 .
Note :- you cant check the received power from FIU Mon port as it intended for Transmit direction.
The cause & solution of the problem
-The insertion loss of that individual channel was too high after passing through the D40 , the cause was that the port in the D40 was contaminated and because the port is female ,so it needed a special tool called “one click ”used for cleaning female ports and laser sources like SFPs .
-After cleaning the port , the power value get to the nominal value , and the “IN PWR LOW” alarm got cleared .
welcome to comment and feedback
