[Case Show] An ONU Frequently Goes Online and Offline Because of Unmatched Optic

Procedure

1. Use an optical power meter to measure the optical path attenuation. It is found that the optical path attenuation is -23 dBm, which is within the normal range of the optical path attenuation.
2. It is suspected that the poor quality of optical signals is caused by the dirty optical fiber connectors of the ONU (OT928). Clean the optical fiber connectors, and remove and then insert the optical fiber connectors again. The fault, however, persists.
3. Replace the ONU with another ONU (OT928) to conduct a test. The fault, however, persists, which indicates that the hardware of the ONU (OT928) is normal.
4. Check the fiber patch cord of the ONU (OT928). It is found that the connector of the fiber patch cord does not match the optical fiber connector of the ONU. Though the connector of the fiber patch cord is square, the color is different. After verification, the optical fiber connectors used in the ONU (OT928) are green, square, and SC/APC.
   http://localhost:7890/pages/31187783/03/31187783/03/resources/public_sys-resources/icon-note.gif NOTE:

   The BOM is 14130252, and the name is Patch Cord, SC/APC-FC/PC, Singlemode-G.652, 3mm, 3m.
5. Replace the fiber patch cord with a correct fiber patch cord (SC/APC-FC/PC). As a result, the LED of the PON port is stable, and the ONU can register with the OLT normally.