NBN FTTP Connection Box Status Lights

The article will explain the meaning of the status lights found on the NBN™ Connection Box (indoor unit) used for Fibre to the Premises (FTTP) services. These lights may help you quickly check on the status of your NBN™ connection which may be useful when troubleshooting NBN™ FTTP issues.

This article will also explain where to find the Connection Box’s Serial Number, which may be required in order to complete an order for NBN™ services.

From mid-2013 onwards, NBN™ Connection Boxes were installed with a plastic cover by default. To access the Connection Box, gently prise the bottom of the cover away from the two clips holding it in place at the bottom of the unit and then lift the cover upwards.

Once lifted, the Connection Box will be partially covered by casing, but you will still be able to see the status lights and access the ports as shown below.


Once the cover is lifted, you’ll see a barcode sticker on the right-hand side of the box. The number next to S/N is the Connection Box’s Serial Number, as shown below.


Light State Meaning
POWER Off No power supply. Please note that all other lights will be off if the Connection Box has no power.
Red Connection Box is operating on backup battery power from the Power Supply unit. If there’s no power outage, try troubleshooting.
Green Connection Box has power. Sometimes the light may look more orange/yellow than green – this is fine.
OPTICAL Off Connection Box is disabled.
Red No connection to the fibre network. Try troubleshooting.
Green Connected successfully to the fibre network. This light will flash during data transfer.
ALARM Off Connection Box is working, but no devices are connected.
Red Issue detected. Try troubleshooting.
Green Connection Box is working with no issues detected.
UNI-D 1/2/3/4 Off Nothing is plugged into this port. Only one UNI-D port is active for a single NBN™ service. This is typically port UNI-D 1.
Orange A device capable of up to 1000Mbps is plugged in. This light will flash during data transfer.
Green A device capable of up to 10/100Mbps is plugged in. This light will flash during data transfer.
UNI-V 1/2 Off There is no NBN™ Fibre Phone service, or it’s not currently being used.
Green One or more Fibre phones are off the hook (typically because they are being used).
One or more Fibre phones have been off the hook for more than an hour. If no one is on a long phone call, check that your handsets are not engaged and have been returned to the hook or cradle.
UPDATE Off Normal, no action required.
Red Connection Box has failed to download an update.
Green Connection Box is currently downloading an update with no issues.


If you’re seeing some really unusual behaviour such as the lights for unused UNI-D ports lit or flashing despite having nothing connected, have there been recent lightning storms in your area?

If you suspect the Connection Box, its cabling or other NBN™ equipment have been affected by a direct or nearby lightning strike.