In any recent Linux distro like Knoppix 6.2 , PCLINUXos 2009 I can use an Sony Ericsson to connect with a usb cable to the wireless internet. (MTN)
Quite sadly this doesn't work out of the box with efw 2.3. I was having visions of how cool it would be to have wireless backup link via my cellphone incase our main adsl does fall over. So this is my misson to get this phone working properly with efw. kernel version 2.6.22.19-72.e18
Firstly I did a dmesg on a distro when the phone is plugged in and working.
That is what i saw... amongst other garble..
[81875.973202] cdc_acm 3-2:3.1: ttyACM0: USB ACM device
[81875.980184] cdc_acm 3-2:3.3: ttyACM1: USB ACM device
[81875.991609] cdc_wdm 3-2:3.7: cdc-wdm0: USB WDM device
When doing the same command on efw i only got two lines.
cdc_acm 1-1:3.1: ttyACM0: USB ACM device
cdc_acm 1-1:3.3: ttyACM1: USB ACM device
My conclusion was that cdc_wdm was missing and needs to be loaded!
I heroically typed in modprobe cdc_wdm but it spat back at me: "FATAL: Module cdc_wdm not found."
I Google for this module but eventually realized to my horror i will have to compile this kernel module from source on a distro that does not have kernel headers or even a compiler installed.
Anyway after a bit of TIME I manged to setup all the necessary tools to compile a kernel module by following some of the instructions that Joekville had posted in the forum h t t p : / /efwsupport.com/index.php?PHPSESSID=3e2f64875a5f16fe30de57f3208d25fb&topic=610.msg1697#msg1697
Right then after quite a bid of goggling I found the source code for the cdc_wdm module here h t t p : / /osdir.com/ml/linux.usb.general/2008-05/msg00304.html
Yes, it's not the prettiest but it's the best i could find.
Then I carefully removing only the +'s at the beginning of the source so that i could compile it.
Recreated the makefile to suite my particular needs.. This website came in very helpful when doing this.. h t t p : / / w w w.cyberciti.biz/tips/compiling-linux-kernel-module.html
After quite some pain and a lot more time. I managed to compile cdc_wdm.c into a cdc_wdm.ko module that loaded and actually worked. Whoohoo :-D
When I do a: dhclient USB0 it gets a dhcp address and I am able to ping any ip address on the Internet.
So it works now but dns is not working at all, Yet....
I am uploading the cdc_wdm.ko module. It's quite a mission to compile it yourself and i wish someone had already done so and uploaded it for me. I also suspect that cdc_wdm covers quite allot of phones and not just the Sony Ericson K550 as in my case. If you want source and makefile, just ask me, i'll upload them too.
Now I need to figure out a way to add this usb0 interface to the web interface so that it can be managed from there. Anyone have any clues how to add an additional interface as a uplink in efw ? 
Author