so you go to Yast: you enter your root password; you select network devices and then modem;
then you add a device: is yours listed?
sounds also like we need to find what port the modem is assigned to;
here is a description from another linux forum on how they configured a similar modem
Choosing external modem for Ubuntu [Archive] - Ubuntu Forums
My D-LINK DFM-56EL external modem now works with Ubuntu 6.10 (the mouse did not work on 7.04).
Here is how I installed it:
downloaded Gnome-ppp using another computer. Copied to CD.
inserted CD in CD-drive on Ubuntu PC.
An icon representing the CD becomes visible in the Ubuntu window.
double-clicked on CD icon to install gnone-ppp.
The installer puts the Gnome dialer in the same
submenu as Firefox, Evolution mail etc
click GNOME PPP submenu item and enter Username, Password
and telephone number (in my case from a prepaid Internet card)
Click Setup button at the bottom of the GNOME PPP dialogbox.
Select device from dropdown list
/dev/ttSy0 corresponds to Windows COM1
/dev/ttSy1 corresponds to Windows COM2
Select device type from dropdown list: ‘Analog Modem’ in most cases
Select modem speed: 57600 for a 56K modem
Leave all other settings as they are. Close Setup
Click Connect button on GNOME PPP dialog and you will hear
the modem connect signalling.
you can see they used a PPP programme, and their device was assigned to /dev/ttsy0
(I remember such terms from our days of a dial-up modem);
here is an entry from another linux forum
dial up setup was “How do I dial using external modem” - Linux Archive
I have a USRobotics usr 5637
that works, plug it in and setup on ttyACM0.
During the pppconfig setup, where it cannot find your modem, you will
need to select manual and put in
ttyACM0 that usually works for me If you put your ISP in the “Provider”
line, you will need to type
pon and “what you put in the provider line” If it wasn’t changed pon
so they recommend a setting they call ttyACM0
can you see any such possible settings
the worrying thing too is that this guy
gnulinuxclub.org - Configuring Ethernet Modem On LINUX Machine
seems to know about configuring USB modems; and recommends being very wary of them …
so see if you can give us some of the information as above