Re: SMS sending error with Telit module

[Dan Williams <dcbw redhat com>]

On Tue, 2013-04-09 at 10:35 +0200, Enrico Murador - Research &
Development - CET wrote:
> On 08/04/2013 17:28, Dan Williams wrote:
> > On Mon, 2013-04-08 at 10:39 +0200, Enrico Murador - Research &
> > Development - CET wrote:
> > > I'm trying the packages I updated friday from PPA, but now I'm facing
> > > another problem: after I start the gsm data connection, most of the time
> > > connection drops automatically... sometimes immediately after
> > > connection, sometimes after some seconds (and in the meantime, I see the
> > > modem status icon on top right of the screen in "searching" state).
> > > After the connection drops, the modem seems to become "unreachable" from
> > > the manager. I can get it working by disconnect and reconnect the
> > > module's USB cable, without powering it off.
> > >
> > > Side effect: one time, after some retries, I was able to completely
> > > "lock" the applet with both LAN and mobile connections disabled, and
> > > clicking on the connection names didn't make any effect, apart from this
> > > message repeatedly popping up: "(4) Did not receive a reply. Possible
> > > causes include: the remote application did not send a reply, the message
> > > bus security policy blocked the reply, the reply timeout expired, or the
> > > network connection was broken.".
> > >
> > > Attached is the log of a failed attempt, where connection drops (line
> > > 755) some seconds after going up, and subsequent (failed?) attempts to
> > > check module's state.
> > > Is there a way to show in log also the cause of the disconnection?
> > If NetworkManager is being used here, what does the PPP exchange look
> > like?  Does ppp0 get an IP address from pppd before the disconnection,
> > or does the PPP negotiation just fail?  You'll see that wherever syslog
> > gets dumped to, sometimes /var/log/messages,
> > sometimes /var/log/daemon.log, etc.  Clearly the modem isn't completely
> > wedged because the QCDM port still works.  But getting the pppd output
> > might help diagnose.
> >
> > Some theories are:
> >
> > 1) double-check the APN
> >
> > 2) perhaps PPP fails for some reason, but when pppd quits on the local
> > machine the module doesn't actually leave data mode; we don't have
> > multiple AT ports so there's no way to force the device to leave data
> > mode with AT+CGACT.  The device might require other mechanisms like
> > serial HUP or dropping DTR or +++.
> >
> > Dan
>
> To check PPP, I suppose I must enable NetworkManager logs (maybe using 
> --no-daemon option?)... What is the best way do it?

Yeah, best is to stop NetworkManager, then run manually with:

NetworkManager --no-daemon --log-level=debug --log-domains=core,hw,device,mb,ppp

and the pppd debug output will get printed in-line with the
NetworkManager log output.

Dan