Learn about optical network terminal status lights

You can use the status lights on your optical network terminal (ONT) to help find and fix internet issues. An ONT may also be called a Service box.


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ONT connections
If you’re having issues and can’t get your ONT to power up, contact us.

Status lightStateDescription and action needed
POWERGreen (solid)The ONT is on.
OffThe ONT is off. You should:
  • Make sure the network power cable is plugged into a working outlet.
  • Press the power button to make sure the power is on.
RedThere’s a problem with the ONT.
PONGreen (solid)The ONT is connected to the AT&T network.
Green (flashing)The ONT is connecting to the AT&T network.
OffYou should:
  • Make sure the power LED is solid green.
  • Check the fiber cable to be sure it’s connected to the PON port.
If both of these look good, check for local internet outages.
ALARMOffThe ONT is working properly.
Red (solid)The ONT isn’t working as expected. Make sure the fiber cable is connected to the PON port.
DATAOffThe Ethernet isn’t working. You should:
  • Make sure the power LED is solid green.
  • Check both ends of the red ONT cable provided in your box. It should be connected to the Ethernet port of the ONT and the red ONT port on the back of your gateway.
  • Make sure the ONT port LED on the back of your gateway is green.
Green (Solid)The ONT is connected to your gateway at 10 or 100Mbps.
Green (flashing)The ONT has data activity at 10 or 100Mbps.
Yellow (Solid)The ONT is connected to your gateway at 1000Mbps. (Service speed may vary)
Yellow (Flashing)The ONT has data activity at 1000Mbps. (Service speed may vary)

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Indoor 020 ONT
If you’re having issues and can’t get your ONT to power up, contact us.

Status lightStateDescription and action needed
PWRGreen (solid)The ONT is on.
OffThe ONT is off. You should:
  • Make sure the network power cable is plugged into a working outlet.
  • Press the power button to make sure the power is on.
BTRYOffThis isn’t used for your AT&T internet service.
FAILOffThe ONT is working as expected.
Green (solid)There’s a problem with the ONT.
Green (flashing)The ONT is connecting to the AT&T network.
LAN 1GGreen (solid)The ONT is connected to your gateway.
Green (flashing)The ONT has data activity.
OffThe Ethernet isn’t working. You should:
  • Make sure the power LED is solid green.
  • Check both ends of the red ONT cable. It should be connected to the Ethernet port of the ONT and the ONT port on the back of your gateway.
  • Make sure the ONT port LED on the back of your gateway is green.
LAN 10GOffThis isn’t used for your AT&T internet service.
NTWKGreen (solid)The ONT is connected to the AT&T network.
OffThe ONT isn’t working as expected.
MGMTGreen (solid)The ONT is connected.
Green (flashing)The ONT is downloading software.
OffThe ONT isn’t connected to the AT&T network.

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Outdoor ONT
Check to make sure the power supply LED is On and Green. If it isn’t, make sure it’s plugged in to a working outlet.

If it’s plugged in and still not working, contact us.

Last updated: February 14, 2024

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