I use internet via GPRS (my provider is GSM). I think the setup is basically the same for you too. Just change the device settings to /dev/ttyACM0 or as the case may be.
I'll tell you what I did
1. in the shell 'dmesg | tail' after I plug in the modem (which has a USB cable in my case).
2. if the drivers are recognised, go to step 3. If not, use a driver like cdc-acm. I use it as the driver. Type 'modprobe cdc-acm' after you have inserted the modem. Then the device is designated something as /dev/ttyACM0
3. You should have wvdial. In some distros (such as Fedora) I've found it only to work with the root user. You can change this. Else log in as root, when you 'wvdial provider' in the command line.
4. Edit the wvdial.conf file appropriately. The parameters you've to enter are: 'APN', username, password & Modem. All other options are mostly similar for most providers. You can also enter the extra initialisation command as "Init4= ........". Remove the Init string you don't require.
See my wvdial.conf below. Make appropriate changes:
------------------------------------
[Dialer provider]
Modem = /dev/ttyACM0
#Baud = 115200
Init1 = ATH
Init2 = ATE1
Init3 = AT+CGDCONT=1,"IP","APN","0.0.0.0",0,0
# Some phones like the NEC DB7000 don't like empty strings, so an address must
# be provided
#Init3 = AT+CGDCONT=1,"IP","internet","0.0.0.0",0,0
# Some phones don't like the quality of service parameters:
# Init4 = AT+CGQREQ=1,0,0,0,0,0
# Init5 = AT+CGQMIN=1,0,0,0,0,0
Dial Command = ATD
Phone = *99#
# Phone = ATD*99***1#
Username = username
Password = password
---------------------------------------------------
The link that has been of most help to me in this:
http://kapsi.fi/~mcfrisk/linux_gprs.html
