Giuseppe,
ModemData.txt says how to fetch and install the driver which you need.
BEGIN QUOTE FROM MODEMDATA.TXT
The hsfmodem package serves a great variety of Conexant chipset modems.
From http://www.linuxant.com/drivers/hsf/full/downloads-ubuntu-x86.php
download hsfmodem_VersionSpec_k2.6.20_15_generic_ubuntu_i386.deb.zip
with 2.6.20_15_generic equivalent to
2.6.20-15-generic, your kernel version.
Under Linux unpack with:
$ unzip hsfmodem*.zip
Then install with:
$ sudo dpkg -i hsfmodem*.deb
Subsequently, the modem should be found with
$ sudo wvdialconf /etc/wvdial.conf
Edit in your personal information with:
$ sudo gedit /etc/wvdial.conf
and try dialing out with:
$ sudo wvdial.
See Testing.txt for details.
Read Conexant.txt
END QUOTE
Giuseppe wrote: