In my case, this has been a so-called web'n'walk Stick from Germany's T-Mobile, which I intend to use for connecting to the Internet on travel. Unfortunately, I am quite frequently on the road, or visiting customers, where I cannot connect my Laptop to the network, so this thing will come in quite handy.
Would I be a Windows user (or perhaps a Mac fanatic), this wouldn't be worth posting: Of course, the device is neatly trimmed for Windows, making almost everything automatic. Basically, you plug it in, enter your PIN, and that's it. Not so with Linux, or (to be fair), at least not with Fedora Linux. I've got it running now (in fact, this post is written with the Ethernet disconnected), but that's after several hours of recherche, postings in mailing lists and in the Fedora Forum (not that these had any results). As usual, you need to understand what's going on, making yourself known to technical concepts, command line utilities and configuration files, which you never intended to know. And that's the reason for writing this: Perhaps I can save some other persons time.
The first thing to understand is this: In order to make life easier for Windows and Mac users, the device is running in one of two quite different operation modes. The first mode is the default mode: The stick acts as a very small USB drive. On Windows, this allows to automatically install software from it. Needless to say, there are no Linux drivers. (The good news: All drivers came as part of Fedora. :-) Also needless to say: This default mode is not what you want. You must deactivate it and switch to the other mode, where you can actually use the stick. (I assume that the installed software does that automatically on Windows.)
There are several tools and utilities for doing this switch: usb_modeswitch (which I choosed, because it comes with Fedora), rezero, ozerocdoff, and perhaps a multitude of others. (My guess is, it would help, if distributions could agree on a common choice here.) These tools typically need some configuration. To obtain this configuration, start looking at the output of
[jwi@mcjwi ~]$ /sbin/lsusb
Bus 001 Device 005: ID 413c:8103 Dell Computer Corp. Wireless 350 Bluetooth
Bus 001 Device 006: ID 0b97:7762 O2 Micro, Inc. Oz776 SmartCard Reader
Bus 001 Device 004: ID 0b97:7761 O2 Micro, Inc. Oz776 1.1 Hub
Bus 001 Device 002: ID 413c:a005 Dell Computer Corp. Internal 2.0 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 004: ID 0af0:6971 Option
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
If you don't know, which line belongs to your stick: Just remove it, run the program again, and see what changes. In my case, the interesting part is
Bus 003 Device 004: ID 0af0:6971 Option
The ID consists of two parts: The so-called vendor ID (0af0) and the product ID (6971).
If you have usb_modeswitch, you might inspect a file called usb_modeswitch.conf (in my case /etc/usb_modeswitch.conf) and search for the above ID's. There's a good chance that you find them there. If not, enter them into Google, together with usb_modeswitch as an additional search term. Again, there's a good chance to find something. If not: Bad luck. I don't know what to do in that case, but I guess consulting the above tools mailing lists, forums, or whatever.
In my case, I've learned from the configuration file and some Internet pages that I've got to enter the command
sudo usb_modeswitch -v 0af0 -p 6971 -P 6971 -m 0x05 -M 55534243785634120100000080000601000000000000000000000000000000
to change the mode. First step done. If everything's fine, the following command should now provide some meaningful output:
[jwi@mcjwi ~]$ hal-find-by-capability --capability=modem
Now enter NetworkManager (aka nm-connection-editor) and switch to "Mobile Broadband". Press "Add" to create a new connection. If you're lucky, you will find a popup like the following:
The second and third entry are default entries. The presence of the first entry shows you that NetworkManager recognized your stick. Needless to say: In my case, it didn't. After consulting the home page of usb_modeswitch I found out, that I need to load some other driver explicitly:
In your case, this might be usbserial, rather than option. Sorry, can't help you here.
But if you can choose your "modem": Almost there! (Not yet, of course.) NetworkManager will open a window like the following:
(In the US, or to be precise, with CDMA this might look quite different.) The PIN and the PUK are what you get from your mobile broadband provider. If you're even luckier, the provider will tell you the other data as well, in the written data sheet, or at least on the hotline. Perhaps, you already guessed it: My provider didn't. ("We aren't supporting Linux.")
To find the remaining data, use Google again. In my case, the relevant search terms have been "T-Mobile APN PIN". (Simply is a reseller of T-Mobile) Another choice might be to consult the list of operators on the Gnome site. I've found the following entry there:
Tells me the APN (might be some servers host name?), and the password. (You should be able to ignore the DNS servers, as they are configured automatically.) In my case the user name was missing, but some more googling revealed the user name "Internet".
Believe it or not, but now it's working! (Might be, that you need to click on the NetworkManager's applet, if you didn't choose "Automatic Connect" and activate the connection.)
And now you know, why I clearly prefer a lot of Linux experience in profiles or curriculum vitae, when my employer hires: People who deal with that stuff should be ready for the problems we provide them with...