Yes, you can often use your existing router with fiber optic internet, but there are crucial considerations. Understanding compatibility, potential limitations, and when an upgrade is necessary will ensure you get the most out of your high-speed connection. This guide will break down everything you. In this comprehensive guide, we will walk you through the steps to effectively use your own router with AT&T Fiber service. Buck DirecTV AT&T Model EPS48R0-16 / EPS48R1-16 Replacement AC Adapter. Yes, fiber internet requires specific equipment including an Optical Network Terminal (ONT) and a compatible router. Your internet provider typically supplies and installs the ONT, while you can use provider.