Locate the fiber optic wall outlet: This is where your ISP's fiber line enters your home. Power on the ONT: Use the provided power adapter. 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. This device converts incoming light signals into electrical signals compatible with standard networking equipment. It's thin, flexible, and usually. The ONT is usually a compact box installed near where the fiber enters the structure, often on an interior wall or in a closet.