About your Optical Network Terminal (ONT) About your Optical Network Terminal (ONT) Traditional telephone service uses copper wire to transmit communications signals. Verizon FiOS, however, transmits signals using hair-thin strands of glass fiber and laser-generated pulses of light.
When that light reaches your home or office through the Verizon network, it is converted into electric signals in a box, called the ONT, installed onto either the outside or inside of your location. That way, it can be "read" by your telephones and computers. Information that is sent from your location will be converted from electric signals to light inside the ONT.
Unlike traditional self-powered telephone service, your Verizon FiOS service depends on your location's power source.
The ONT has a power cord that goes into your location through the ONT Power Supply Unit where it plugs into an existing standard electrical outlet.
Important: To ensure connectivity to the Verizon FiOS network, make sure your ONT Power Supply Unit is plugged in at all times.