first welcome to the troubling linux community
there is a company named after Conexant,
website who has the driver for your modem.
the driver itself used to be free, as of in beta testing mode. the beta works pretty good, so i think that's why they wouldn't let you download the full version anymore, but a limited versio which makes your modem transfer data at 15kps.
yea, you have to pay some $ for the latest version of the driver.
But don't start counting your money now
many people online hosts the old free beta version, which was legal and it enable your modem operates at full speed, 56kps.
there are two types of conexant modem.
one is hsf and another is hcf
for this, you have to run a little
program to determine which one it is
after u test it out, you can obtain the old free beta driver from the site in my sig