I used to do support for Efficient networks' brands of DSL modems for a
year and a half as a mentor of the first level modem and router support
The USB version 4060 was a close clone to the Alcatel speed touch
home modem. The driver for the windows version has a high overhead as
far as system resources go.
I know Efficient was not interested in making Linux drivers or any
OS other than a Microsoft OS driver. So you may need to switch to a nic
and an ethernet based DSL modem/router.
A couple of things to consider is ...when you get a driver for Linux
you will need to setup the VPI/VCI manually and PPPoE software that is
usually proprietary to the service carrier. If you find a driver for
that modem (highly unlikely but good luck) Linux has built in PPPoE
software you can use to get connected.
I'm not the end all know all of USB based DSL modems but when I would
get a call for linux support I was told to say "no support for Linux and
I know not where you can look for drivers or we'd say in a year or two".
I never saw a Linux driver that worked... It may have for someone but
not that I have seen for USB anyway. It would be less trouble to find an
ethernet based modem and it wouldn't be a system hog... (IMHO)
Keep checking back as someone else may have newer info than I do though...