Try these troubleshooting methods if your AT&T Wireless Internet does not produce a dial tone when a phone is plugged in.
INSTRUCTIONS & INFO
Make sure the power cord is plugged into the AT&T Wireless Internet and a power outlet. Do not connect the AT&T Wireless Internet to a power outlet that is controlled by a wall switch.
Make sure your AT&T Wireless Internet is powered on. Switch the power button to ON to turn on the device.
Make sure that your cordless phone has power, and is connected properly to the AT&T Wireless Internet.
Move your AT&T Wireless Internet to an area with a stronger cellular signal, typically near a window or outside wall. Note: Three to four green/blue bars indicate a strong signal and is recommended for optimal performance. Less than three bars indicates a moderate signal and may be sufficient.