For X customer, we are implementing a metropolitan NG WDM network with OSN8800 and OSN6800 equipment. We are currently using U2000 V100R003 version.
The currently used U2000 version is V100R003 , the OSN8800 version is 5.51.06.14.
During deployment, when we were making sensitivity tests, the SDH analyzer reports bit errors, even when we were in the acceptable optical input power range of the board.
We are using the following scheme in order to test the port sensitivity (Please check the attached document)
Following this procedure:
1. Adjust optical attenuator. Increase the attenuation of the optical attenuator so that the ratio of bit errors detected by the test meter is extremely close to but not larger than the specified BER (10-10).
2. Remove the fiber at the RX port, and then connect the fiber to the optical power meter. Measure the optical power. The optical power obtained is the receiver sensitivity on the WDM side.
The SDH analyzer shows FRAME alarms.
1.Check the SDH analyzer, by making a loop in the equipment, it was OK.
2.Check if optical power is normal in the INPUT of the SDH analyzer, and also in the INPUT of TQX board port. Those are in the normal range.
3.Change the clock source in the SDH analyzer, from INTERNAL to RECEIVED or RECOVERED.
After this last step, the FRAME alarm disappeared on the SDH analyzer, and the test run normally without bit errors in the normal optical power input range for the TDX board.
The OSN8800 has an internal clock source in each NE, when we connected the TDX board with the SDH analyzer; they’ve different clock sources, this difference cause loss of frames and bit errors.