BGW210-700 Broadband light is solid red but I still have internet. Why is it red?

You apparently have dual-pair service, meaning your connection to the AT&T network equipment is supposed to use two lines.  Right now, if your broadband light is red, but service still works, ONE of your TWO lines is not working properly.  

Use the myAT&T app or Smart Home Manager to detect and report the issue and set up a service appointment, or call 800-288-2020 to essentially do the same (after 30 minutes of inane troubleshooting you likely have already done).

There's only one line going into the router.

That one "line" or cable that runs from the wall to your Gateway normally would have 4, 6 or 8 individual wires, organized in pairs of wires in twisted-pairs (the cables are usually called "twisted pair cables" and actually unshielded twisted pair, UTP, cables).  The two wires of each active pair, what we would call a line, carry part of a complete circuit from the line card in the VRAD.  That circuit runs through the cable bundle from the VRAD/crossbox to the pedestal near your home, through the drop to your NID, and from the NID to your Gateway.  The problem with the pair that isn't working could be the port in the line card in the VRAD or a connection anywhere along the way to your Gateway.   It could have been accidently disconnected from the port at the VRAD.

JAROD!!! Telling them to ignore a dead line??  How could you?!?

We now notice the person on the other end of a phone call cannot hear the person on the landline phone. Since we do not use the landline very often, although this red light has been on a couple weeks, it wasn't till last night that we realized this problem when making/answering a phone call. Related to Broadband/line issue?

We're here to assist with your equipment concern, @bmeganck! 

Since your equipment is showing a red light, let's move this conversation into a direct message. This way we can run some tests to determine the cause of this. Be on the lookout for a chat notification in the upper right-hand portion of the page, next to the bell icon.

We look forward to speaking with you!

CalebP, AT&T Community Specialist 

Has Att been asked to do a line quality test?  If they detect an issue, they can schedule a service call. 

Let's get your gateway working properly, @bmeganck! 

Thanks, @JefferMC and @gr8sho for your input. 

We recommend troubleshooting your gateway if you haven't already. 

1. Unplug the power cord from the back of your gateway or modem. If you have: 
   • An internal battery backup, remove it
   • DSL, unplug the phone cord from your modem or gateway
2. Wait 20 seconds.
3. Put the internal battery back in if you have one. 
4. Plug the power cord back in. If you have DSL service, reconnect the phone cord.
5. Wait for the gateway or modem to restart and your Broadband light to turn solid green. This can take up to 10 minutes.

You may also want to check to make sure all the cables are secure. 

If this doesn't help, please let us know! We can get a tech appointment scheduled in a direct message.

Raiden, AT&T Community Specialist 

I ran the troubleshooting steps recommended by Raiden but the Broadband light still returned to solid red. How do I schedule a tech appt via DM?

Did Raiden end your chat without doing so?