Re: Persistent 3G connection fails, not sure why

[Alexander Karlstad <alexander karlstad be>]

Den 27. okt. 2011 08:29, skrev Dan Williams:
> On Mon, 2011-10-17 at 09:49 -0400, David Pfeffer wrote:
> > I maintain a persistent 3G connection on a remote device using network
> > manager. However, every so often, the link fails and then does not
> > restart itself. I managed to identify an occurrence of this in my
> > syslog, but honestly I'm not really sure what I'm looking at. It seems
> > that the machine thinks the device has been unplugged, but there's no
> > corresponding log entry for it actually being unplugged.
>
> ALmost seems like the modem crashed and reset itself.  What kind of
> modem is this and what model?

I'm having a similar issue on my Thinkpad Edge 13 with the built in Gobi 
2000 WWAN module. Though, my "connection terminated" happens after the 
"modem hangup", and it seems to happen very sudden according to the 
syslog[1] (last entry in the log was several minutes earlier).

I found a bug report[2] a while back that /could/ be related but I 
joined this list in search for answers. Another bug report[3] contains a 
possible patch, but according to the person submitting it, it didn't 
really work that well:

> I found afterwards that the patch fixed only
> partially the problem. I saved a log message "<info> disconnect
> failed: (32) The serial port is not open." that eventually happened,
> hoping to further research about the issue later. However, I didn't
> immediately found a way to reproduce the bug in a controlled
> environment. What I was doing for testing the patch before was to kill
> pppd, trying to simulate a modem hangup, but it didn't appear to
> simulate this other condition I was observing. After that I nearly
> stopped using USB modems as I bought an Android mobile phone capable
> of tethering.

Hoping someone could help because I'm getting pretty sick of it.

[1]: http://pastebin.ubuntu.com/720446/
[2]: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/789508
[3]: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/566812

--
Alexander Karlstad
launchpad.net/~carestad