Subject: Re: cellphone modem troubles
To: Matthias Ferdinand <>
From: Ignatios Souvatzis <>
List: tech-net
Date: 12/26/2006 22:24:37
On Tue, Dec 26, 2006 at 06:26:35PM +0100, Matthias Ferdinand wrote:
> --On Dienstag, Dezember 26, 2006 08:26:17 +0100 Ignatios Souvatzis 
> <> wrote:
> >This happens when ppp connection is trying to start negotiation while
> >the modem is in command mode.
> >
> >crtscts should be ok; combine with (no)modem and maybe (no)local.
> >
> >And try /dev/dty00 as mentioned above.
> >
> >>I am running out of things to try. Can somebody give me some more hints?
> >>Perhaps I need to look into 8N1 (... not 8-bit clean ...), where is this
> >>set in pppd (or outside of pppd?) ?
> >
> >Always.
> >
> >If this doesn't help, we'd need a log of the PPP negotiations to find
> >out what happens - use kdebug 7 and log the kernel debug messages to
> >some file using appropriate syslog.conf settings.
> Hello,
> thanks for your answer. Tried /dev/dty00, modem, local, but none of this
> makes any difference. kdebug 7 does not show any packets, the link is
> terminated before ppp takes place, this could be confirmed on the dialin
> server side.

> Then I started hacking at pppd. In main.c, it decides "Modem hangup"
> whenever the read from the ttyfd returns with zero length. I disabled
> this code section, and here is the result:

[Deleted by me]

None of this is relevant - if the kernel signals EOF to the userland pppd,
you can't help by ignoring it. Maybe the answer to the 3rd question below
will tell us why it thinks it should do that.

1st question: do you run pppd as root? If not, please do.

2nd question: is the Siemens phone connected by an USB cable or by an
RS232 cable? (Some USB-RS232 dongles have carrier detection
problems in NetBSD-3ish OS kernel versions, and the Siemens USB cables
are RS232 over USB in disguise. In this case, a netbsd-4 beta2 kernel
should help.)

3rd question: can yo please increase the "debug" count to pppd, and show
us pppd's debug output?