Is there existing any methodology to test security of modems?

I am not asking about “war driving” (penetration testing of modem entry
points to the computer systems/networks) but testing of modems as devices?

What features shall one look for while assessing the security of modems
of various types (dial model, cable modem, DSL modem, GPRS modems, other
wireless modems, etc)?

Are there any publicly accessible (or commercial) modem testing tools?

Thank you,
John

Passmark makes an inexpensive Windows based software test tool.

http://www.passmark.com/products/modemtst.htm

That would be “war dialing” hanging with the old school terminology.

One of the things you want to look for on modems is if they are set to
“auto answer”.
What applications are being used in conjunction with the modem and how
are they configured.
What authentication is being used by those applications (and how
secure/reliable the authentication is).
Also look to see if any encryption is being used. Keep in mind that
all communication goes over POTS and the providers can monitor any
line they want to at any time.
What services are available over dial-up.

Google