Re: Looking for advice about using NM with a Sprint U301 modem

[Dan Williams <dcbw redhat com>]

On Wed, 2010-06-02 at 12:54 -0400, Daenyth Blank wrote:
> On Wed, Jun 2, 2010 at 08:12, Daenyth Blank <daenyth gmail com> wrote:
> > On Wed, Jun 2, 2010 at 03:16, Dan Williams <dcbw redhat com> wrote:
> >> On Thu, 2010-05-27 at 12:04 -0400, Daenyth Blank wrote:
> >>> Hi all,
> >>>
> >>> I'm trying to find out some information regarding the Sprint U301 3G
> >>> modem. Our use case for it is that it will be attached to an embedded
> >>> machine running ubuntu with networkmanager, in addition to our
> >>> software. I've been trying to get this modem to connect reliably and
> >>> am having some issues with it. I've added a udev rule so that the
> >>> usbserial driver is given the correct vendor/product information, and
> >>> it connects automatically on boot, but not reliably. Some boots it
> >>> does not connect at all and won't until I reboot. Sometimes it
> >>> disconnects while the machine is running. If it disconnects either by
> >>> itself or from deactivating the connection, it will not connect again
> >>> and needs a reboot. The nm/mm logs say that serial requests are timing
> >>> out when it's in the non-connected state. I haven't been able to
> >>> recover from the disconnected state with anything about a reboot.
> >>>
> >>> Is there anything we can do with this device to increase reliability?
> >>> Failing that, can you recommend a usb Sprint 3G modem that will be
> >>> more reliable? If there are none, do you have any recommendations for
> >>> any brand of 3G modem that will work well in this situation? The boxes
> >>> will be deployed where manual access is not easy, so it needs to be
> >>> able to connect and recover from disconnections automatically, or at
> >>> least in a way that can be scripted easily.
> >>
> >> You're certainly not going to be able to get the WiMAX part of the
> >> device working automatically since we dont' have drivers for the Beceem
> >> chipset of the WiMAX side.  However, the EVDO side should work with
> >> cdc-acm, so if you have to use 'usb-serial' there's already something
> >> wrong.
> >>
> >> I suspect you need to use usb_modeswitch to eject the fake CD that the
> >> device provides too, correct?
> >>
> >> Honestly, UTStarcom-based devices (which the 300 and 301 are rebrands
> >> of) often don't work that well as you've found out.  I'd recommend a
> >> Sierra device instead, as Sierra is also very active in Linux kernel
> >> development and has great support for their devices.
> >>
> >> Dan
> >>
> >>
> >
> > Thanks Forest, Dan. I'm going to recommend to our client that we use
> > the Sierra cards. Appreciate the advice!
> >
> 
> I'm looking into the 598 now, and I'm having a little trouble getting
> NM to recognize it. I plug in the device and I can see by using dmesg
> that the sierra driver gets loaded, but when I run
> nm-connection-editor and try to edit the connection, it doesn't get
> listed in the device dropdown. Is there anything I have to do to get
> it recognized? I also haven't been able to find any good guides on
> setting it up. I'm running Ubuntu Karmic right now.

It should show up in the menu after a few seconds.  Try grabbing some
debugging information as described here to figure out why things aren't
working:

http://live.gnome.org/NetworkManager/Debugging

under the "Debugging NetworkManager 0.8.x 3G connections" section.
Basically, we want to get modem-manager logs to find out why the modem
doesn't appear to be found.

Dan