how to get connection with usb modem?

[rusty]

Again, if you post the output from lsusb, we may be able to identify the chipset the modem uses. open a terminal and type: lsusb. The output should look like this:

$ lsusb
Bus 005 Device 002: ID 05dc:b018 Lexar Media, Inc. Multi-Card Reader
Bus 005 Device 001: ID 0000:0000
Bus 004 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 003: ID 0572:1280 Conexant Systems (Rockwell), Inc.
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 003: ID 03f0:0107 Hewlett-Packard CD-Writer Plus
Bus 001 Device 001: ID 0000:0000

It shows what devices are seen on the usb bus. In this example, the usb modem is the Conexant Systems entry. I works with 2.4 and some 2.6 kernels with the acm module (2.4) or cdc_acm (2.6) module loaded. It shows up as /dev/usb/ttyACM0 in kppp.

HTH.