Compatible router: Verify that your router supports fiber optic input (look for an SFP or WAN port labeled "ONT" or "Fiber"). Fiber optic cable: Typically a thin, yellow cable with specialized connectors (SC/APC or SC/UPC). These cables support data transfer rates of up to 10Gbps—critical for. To connect your fiber optic cable to a router, ensure you have the following: Fiber optic modem (ONT): Most fiber connections require an Optical Network Terminal (ONT), provided by your ISP. Here's a step-by-step guide to help you through it. The process depends on the equipment you're connecting.