ATT Internet users in Bay area use Motorola ARRIS NVG589 Gateway.
The device can also used for VOIP.
My parents in law have this device since last month.
The Admin interface is http://192.168.1.254
Access code is printed on the device label.
I found three guides online. Saved here for future referenc.
Motorola NVG589 VDSL2 Gateway