Re: NM 0.9 with Sierra USB 305 modem connection problems

[Dan Williams <dcbw redhat com>]

On Fri, 2011-08-26 at 03:48 +0700, Arief M Utama wrote:
> On 08/26/2011 03:27 AM, Dan Williams wrote:
> > On Fri, 2011-08-26 at 02:55 +0700, Arief M Utama wrote:
> >> Hi all,
> >>
> >>
> >> I'm using Debian's NM 0.9 with MM 0.5 (from experimental repo),
> >> with Sierra Wireless modem USB 305 (USB id: 1199:68a3) mobile broadband
> >> connection does not work.
> > When the modem is inserted, is the 'sierra_net' driver loaded?  Any
> > chance you can get ModemManager debug logging so we can diagnose?
> 
> Yep, it is loaded.
> 
> 
> > http://live.gnome.org/NetworkManager/Debugging
> >
> > the instructions under "Debugging NetworkManager 0.8.x 3G connections"
> > still apply to 0.9.  FYI I have a 306 that I've tested with so at least
> > we expect it to work.
> 
> Following that instructions, herewith I attached the log result. Bit 
> more info, I already created a "Telkomsel Flash" connection using 
> nm-connection-editor, connecting by clicking on it from the gnome-shell 
> applet.
> 
> Tried twice, same result no connection. On first try it shows "you are 
> connected" notification but it's actually not connected (probably a 
> gnome-shell issue). On second try it just went to disconnected message 
> quickly.
> 
> I left my WiFi connection up during the test.
> 
> One more thing, I noted from the debug log, so many AT commands was sent 
> to the modem. Wondered about this, as with my ppp chatscripts, basically 
> I only use following AT commands to make it work flawlessly:

Using wvdial doesn't allow use of the network port the modem exposes,
which limits the connection speed; at the higher 3G/4G speeds we're
seeing these days, PPP just doesn't allow full throughput.  Plus, when
using the network port, we can get connection status and signal strength
on the AT command port, which you can't do when you're using PPP on a
lot of devices.  Basically, MM does a lot more than just connect, it
also delivers status updates, signal strength, SMS, etc.

> --- start chatscript snippet ---
> # cease if the modem is not attached to the network yet
> ABORT        "+CGATT: 0"
> ""        AT
> TIMEOUT        12
> OK        ATH
> OK        ATE1
> OK        AT+CGDCONT=1,"IP","\T","",0,0
> OK        ATD*99#
> TIMEOUT        22
> CONNECT        ""
> --- end chatscript snippet ---
> 
> 
> Hope this helps, let me know if more is needed and thanks for the help.

So the core problem is this:

modem-manager[27390]: <debug> [1314304573.585330] [mm-at-serial-port.c:298] debug_log(): (ttyUSB0): --> 'AT$QCPDPP=1,1,"wap123","wap"<CR>'
modem-manager[27390]: <debug> [1314304573.619827] [mm-at-serial-port.c:298] debug_log(): (ttyUSB0): <-- '<CR><LF>ERROR<CR><LF>'

Grr.  You've got the USB Lightning, which appears to use an Icera
chipset, not a Qualcomm one:

http://sierrawireless.custhelp.com/app/answers/detail/a_id/641/~/can-i-use-a-sierra-wireless-modem-on-linux-machines-%28direct-ip-modems%29%3F

So we need to update ModemManager to use "AT%IPDPCFG" in this case
instead of AT$QCPDPP like we do for Option NV modems that also use Icera
chipsets.

Dan