GSM dongle fails to connect

[Radu Rendec <radu rendec cloudbit ro>]

Hello,

I'm writing to this mailing list because I don't have any better idea
where to ask for help. If this is not the right place, please point me
to the right direction.

I have a strange problem with an USB GSM dongle that I'm trying to setup
with NetworkManager. The strange part is that it used to work with an
older version (an early release of Fedora 16) but stopped working after
an update (Fedora 17, recent version).

I managed to start both NetworkManager and ModemManager in debug mode
and apparently my problem boils down to pppd not being able to establish
any session:

Oct 29 22:05:57 fly pppd[10736]:
Plugin /usr/lib/pppd/2.4.5/nm-pppd-plugin.so loaded.
Oct 29 22:05:57 fly pppd[10736]: pppd 2.4.5 started by blade, uid 0
Oct 29 22:05:57 fly pppd[10736]: Removed stale lock on ttyUSB1 (pid
10533) 
Oct 29 22:05:57 fly pppd[10736]: Using interface ppp0
Oct 29 22:05:57 fly pppd[10736]: Connect: ppp0 <--> /dev/ttyUSB1
Oct 29 22:05:57 fly modem-manager[10624]: <debug> [1351541157.120389]
[mm-manager.c:859] device_added(): (net/ppp0): could not get port's
parent device
Oct 29 22:05:57 fly NetworkManager[10625]:
<warn> /sys/devices/virtual/net/ppp0: couldn't determine device driver;
ignoring...
Oct 29 22:06:16 fly NetworkManager[10625]: <warn> pppd timed out or
didn't initialize our dbus module

I remember that during my debugging session I saw something like pppd
complaining it didn't receive any LCP reply, but I can't remember where
I saw it and what was the exact message.

The bad thing is that, because I upgraded my system, I cannot run a
debug session on the working system to see if anything is different.

However, there are a few strange things that I want to point out:
      * on the working system, usb_modeswitch didn't work automatically
        so I had to use the "option" kernel module to switch it
        manually; on the new, non-working system it gets switched
        automatically, but the vid/pid are the same
      * on the new system, Mobile Broadband is disabled by default; if I
        enable it, I can see an "orange UMTS" entry in the
        active/available connections list. It shows a signal strength
        icon, but the list entry is grayed out.
      * The connection that I used for making the debug capture is
        manually added, using "Edit connections..." -> Add, and then
        selecting my provider/plan from the list. Even though the phone
        number that's configured is "*99#", I can see Modem Manager is
        actually dialing "*99***2#". From what I've read, "***2" is a
        profile selection and maybe that's the problem. Any idea where
        that "***2" is coming from?

I'm an experienced linux user with fairly decent programming knowledge,
so I can assist at least with tests and debugging data if anyone is
willing to help me. However, I don't know anything about the
NetworkManager architecture and GSM modems in general.

At this point, any suggestions are more than welcome, since I'm totally
out of ideas :)

Thanks in advance,

Radu Rendec