First, plug one end of the fiber optic cable into the transceiver and the other end into the fiber optic network. Compatible router: Verify that your router supports fiber optic input (look for an SFP or WAN port labeled. The process to connect fiber optic cable to router requires careful attention to detail, but I'll walk you through every critical step with the precision and clarity you deserve. The fiber line terminates at the Optical Network Terminal (ONT), which is typically supplied and installed by the internet service provider. Make sure the connection is tight to avoid connection problems. You need an intermediary device. This device receives the fiber.