Fiber Connection: Locate the optical port on your router and carefully insert the fiber cable's connector, ensuring a snug fit. Click it into place if it has a locking mechanism. There is a row of ports/button at the rear of the device. The ports/button are displayed from left to. 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. Our Experts are helping user's, who are facing issues with their tech gadgets like Router, Modem and extender.