[ http://warvox.org ] 

WarVOX is a suite of tools for exploring, classifying, and auditing
telephone systems. Unlike normal wardialing tools, WarVOX works with the
actual audio from each call and does not use a modem directly. This
model allows WarVOX to find and classify a wide range of interesting
lines, including modems, faxes, voice mail boxes, PBXs, loops, dial
tones, IVRs, and forwarders. WarVOX provides the unique ability to
classify all telephone lines in a given range, not just those connected
to modems, allowing for a comprehensive audit of a telephone system.

WarVOX requires no telephony hardware and is massively scalable by
leveraging Internet-based VoIP providers. A single instance of WarVOX on
a residential broadband connection, with a typical VoIP account, can
scan over 1,000 numbers per hour. The speed of WarVOX is limited only by
downstream bandwidth and the limitations of the VoIP service. Using two
providers with over 40 concurrent lines we have been able to scan entire
10,000 number prefixes within 3 hours.

The resulting call audio can be used to extract a list of modems that
can be fed into a standard modem-based wardialing application for
fingerprinting and banner collection. One of the great things about the
WarVOX model is that once the data has been gathered, it is archived and
available for re-analysis as new signatures, plugins, and tools are
developed. The current release of WarVOX (1.0.0) is able to
automatically detect modems, faxes, silence, voice mail boxes, dial
tones, and voices.

Presentation: http://warvox.org/media/warvox-1.0.0.pdf 
Gallery: http://warvox.org/gallery.html 
Code: http://warvox.org/install.html 

-HD