Did you see the documentation site? There's a pageon 3G dial-up modem use:
=> http://doc.slitaz.org/en:guides:dialup

It is not working for hauweai usb dongller

I am using a huawei usb dongle (ec1260) no issues. Set it up using the instructions posted at http://doc.slitaz.org/en:guides:dialup. My modem defaulted to ttyUSB2 (although when you look at dmesg, it shows ttyUSB0 to ...4 as connected).

Hi,

After the installation as per you suggestion i donot see the ttyUSB in the dev directory. Hence it am not in a position to use the hauwei usb dongle.

Not sure if this will help, but this is how I got my device working

First install a package called usbutils.
Then in terminal type lsusb
It will bring up something like this:
brenton@trixarian:~$ lsusb
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 1d09:4000 TechFaith Wireless Technology Limited
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

Note that my device ID number is 1d09:4000 - this will be different for you, but the process is the same.

Now go to Control Box , go to the initialization tab, make sure option is in the load module box, if not, add it. Mine looks like this: option snd_als4000 (snd_als4000 being my sound card).

Click the Add Local Commands button and add:
echo '1d09 4000' > /sys/bus/usb-serial/drivers/option1/new_id
Note the numbers, my device's ID number is 1d09:4000, so I added '1d09 4000' above - change these numbers to your device's ID number (remember to exclude the : from the lsusb readout!). Save the file and open a terminal.

In the terminal type:
modprobe -v option
echo '1d09 4000' > /sys/bus/usb-serial/drivers/option1/new_id
and your device should be working - yet again change the ID number to your devices number.

The rest of the http://doc.slitaz.org/en:guides:dialup tutorial should work like expected now.

Hope this helps and works for you!