Hmm. I should mention that I dual boot with Windows sometimes, and in fact it's currently completely broken in there - Fn+F5 doesn't even show it (it shows the other two functions) and my Vodafone program can't turn it on. I tried leaving it on in Linux and then booting into Windows, to no avail.
Vgetty turns your voice modem into an answering machine. It adds voice capabilities to mgetty. This means, that you can handle data, fax and voice calls on one telephone line.
HylaFAX™ is an enterprise-class open-source system for sending and receiving facsimiles. This is the place where users can find HylaFAX+ support, work, and releases. The "+" means that it is better.
IAXmodem is a software modem written in C that uses an IAX channel (commonly provided by an Asterisk PBX system) instead of a traditional phone line and uses a DSP library instead of DSP hardware chipsets.
This document describes how to attach modems to a Linux box and allow it to receive calls to connect users to the network. Its like being your own ISP (Internet Service Provider). If your Linux box is connected to the Internet, then the users will also be