This light indicates whether the ONT is receiving power. Check the power cable and power outlet. For example, a green light might indicate that the device is powered on and functioning normally, while a red light might indicate an error or issue with the connection. If you're using a power strip, check. If none of your devices can connect to the Internet, check the lights on the box on the wall, know as the ONT. The ONT device connects your fibre router to the fibre network. We will look at the different ONT devices that our Fibre Network Operators (FNOs) use, how. The Fibre Connection Box on your wall (the engineers will call this the Optical Network Terminator or ONT ) is where the Fibre comes into your home. The lights on your Fibre Connection Box let you know when everything's working as it should be and can tell you what's wrong if you're having problems. The signal shows a full signal, but the network speed is still slow? What does it mean when the ONU indicator keeps flashing? Plug in and light up, showing whether ONU is connected to power, ONU without power connection is useless.