After many hours of research and desperation I couldn't get my Speedtouch modem to work on linux, on the net there are many howtos (most of them oudated) and none of them worked for me until I tried a simpler aproach with this. This mini-howto concerns only Mandrake 9.0 using a Speedtouch USB Modem with no Ethernet port (Manta) and RP-PPPoE (to emulate a PPPoE - PPP over Ethernet - connection with some sort of dummy driver, tap0).
It may work with older versions of Mandrake or even with other linux distributions, but in this case you're on your own.

You must have installed the development packages, the ppp package and rp-pppoe package, all included in Mandrake 9.0. Also remember to turn off in your bios the Plug and Pray support and enable USB support.

Let's begin then. First get the closed-source binary management app fromAlcatel, as root copy the file mgmt.o from it to /usr/local/sbin (for example). Then download the opensource drivers from here, currently they're at version 1.1, before you compile them you must apply a patch found in their contributions area with:


cd /where/are/the/speedtouch/sources
patch -p1 < /where/you/downloaded/the/patch/speedtouch-1.1-pppoe.diff

then

./configure
make
su
make install

Next as root run:

modprobe tun (to enable the dummy driver tap0, which will sort of emulate an ethernet device)

Then launch also as root the following command:

modem_run -m -f /usr/local/sbin/mgmt.o (or where you have put it)

wait a few seconds and watch the modem lights blink, as root you can issue the command:

tail /var/log/messages to see the output from the kernel

After this as root run:

/usr/local/sbin/pppoa2 -v 1 -vpi * -vci * (the * correspond to the virtual path and virtual circuit id and are unique for each country, for Portugal (my country) it's 0 and 35, you must get this from your ISP or from your Windows Speedtouch program)

Issue again the command tail /var/log/messages to see the output from the kernel

As root run adsl-setup or tkpppoe (in X) to setup your rp-pppoe package, you'll need your username and password, dns, etc. when asked what is the ethernet device to use just answer: tap0

And there you go...

Later you can make some executable scripts to automate the running (as root), like these:

------adsl1-------
modprobe tun
modem_run -m -f /usr/local/sbin/mgmt.o
tail /var/log/messages
-----adsl1eof----

----adsl2--------
/usr/local/sbin/pppoa2 -v 1 -vpi * -vci * &
tkpppoe
----adsl2eof----

(I'm not a linux geek, so they're very simple and work for me)

All I can say is that my connection is stable and everything seems to work fine...



References:

Speedtouch USB Linux Driver Howto

SpeedtouchUSB-Howto

Speedtouch Patch


Thanks to excellent makers of the open-source drivers, they're the best!