To use iaxmodem with Hylafax:

- Install and configure Hylafax

- Take a look to /usr/local/share/examples/iaxmodem/config.ttyIAX to configure the "virtual" modem

- For accepting incoming FAX/data calls, modify /etc/ttys as below
	and send SIGHUP to init process:

>ttyIAX  "/usr/local/sbin/faxgetty"  dialup  on secure

Additional Documentation:
/usr/local/share/doc/iaxmodem
/usr/local/share/examples/iaxmodem
http://www.voip-info.org/wiki/view/Asterisk+IAXmodem