MikroTik GPON ONU SFP: registration questions and a 100 percent failure rate in outdoor summer conditions

A user with a MikroTik GPON ONU SFP module in a RouterBOARD facing a FiberLink OLT saw the interface as registered but the module serial never appeared in the OLT for provisioning. The thread turned into a reliability report: an operator lost every deployed MikroTik GPON module within two months of summer outdoor use (0-70 C rating versus the -40 to 85 C industrial norm), with only a unit in a climate-controlled room surviving; integration with Adtran TA-5000 had otherwise worked.

• Hardware: MikroTik RouterBOARD, FiberLink OLT, Adtran TA-5000
• Transceivers: MikroTik GPON ONU SFP
• Form factor: SFP

Symptoms / messages:

ONU serial not visible on OLT
modules overheating and failing outdoors