res_fax.conf
[general]
maxrate=9600
minrate=7200
statusevents=yes
modems=v29
ecm=yes

udptl.conf
[general]
udptlstart=4000
udptlend=4999
udptlchecksums=yes
udptlfecentries=3
udptlfecspan=3
use_even_ports=yes