Troubleshooting Testing the Modem - 18
A good test to see if the phone line is working is to type “ATDT”,
which will open the phone line. If the modem reports NO DIAL-
TONE, there isn't a valid analog line connected. If the phone line
works, you will hear a dial tone until you press the Return key, at
which time the modem will report NO CARRIER. A No Carrier
message means the phone line was successfully opened.
Other things that can be done here are:
• Call another modem to verify connections.
• Call a working phone number to see if you can successful
connect to an outside line.
• Use the ATI1-17 commands to check firmware versions and
modem features.
• Use ATZ to reset the modem back to its original configuration.