If possible, remove and reinstall the optical modules to check whether the fault is rectified. The SFP/Media Converter is designed for easy use in optical fiber transmission. When the connection does not work as expected after we set it up according to the Installation Guide, we need to do some troubleshooting. The checking include but not limited to the following three aspects: Connection. Check the model of the faulty optical module. If the optical module is installed on a GE port, run the display interfaceGigabitEthernet x/x/x command to view port information when the optical module. Fiber media converter is an ethernet transmission media conversion unit that exchanges short-distance twisted pair electrical signals and long-distance optical signals.