Two OSN3500 devices using SF16E+OBU+DUC docking, need to open 200KM ultra-long distance link, docking is completed, the optical power received up to standard, but there are two SF16E single board are reported BEFFEC_EXC alarm. The signal flow is as follows.

Alarm information

BEFFEC_EXC

Processing

1, check both ends of the SF16E single-board light received respectively -15dBm and -17dBm to meet the acceptance of sensitivity requirements (-28dBm)

2、Use pigtail + light attenuation to make the two SF16E single-board self-loop BEFFEC_EXC alarm disappears

3, SF16E single-board dispersion tolerance of 2400ps/nm (converted to 120KM) receiving end DCU using 80KM module

4, security signal flow SF16E (OUT)-DCU (IN)-DCU (OUT)-SF16E (IN) using pigtail loopback BEFFEC_EXC alarm disappears

5、According to the fourth step of the method, respectively, loopback test OBU1, BPA single board BEFFEC_EXC alarm disappears.

6, at the originating OBU1 (OUT) port plus light attenuation (from 2dBm to 5dBm) to see received SF16E single board alarm still exists and the performance query interface BER continues to accumulate (not a non-linear effect)

7, suspect that the single board mismatch caused by the customer feedback site bar code through the PDM system query are SSN1SF16E single board. Check the customer's two OSN3500 equipment host version, respectively, V2R13 and V1R10 the single board in V200R012C00 and above to support

In summary, SF16E board is not supported in OSN3500 device V1R10 version, in V1R10 version, the network administrator manually add the logical board as SF16, so the docking is not successful.

Root cause

SF16E board is only supported in V200R012C00 and above, this board cannot be used in TDM version.

Solution

The network administrator deleted the SF16 logical single board, pulled out the SF16E single board at the scene, upgraded the equipment from V1R10 version to V2R13 version after wiping the library, plugged in the SF16E single board to add the logical single board (SF16E), the alarm disappeared, and the service was opened.

Suggestions and Summary

SDH long-distance docking scenario is recognized by more and more customers. Whether the docking is successful or not mainly depends on the quality of fiber optic cable. Under different attenuation, different types of fiber optic amplifier boards are used, please configure them according to the long-distance docking guidebook. This fault analysis mainly provides how to solve the problem when the long distance docking is unsuccessful. This problem is more hidden, SF16E single board in V200R012C00 and above to support the use.