From: "Simon Chow" <simonchow@keytechsys.com.hk>
To: linux-ppp@vger.kernel.org
Subject: Re: pppd and AT+WMUX(Multiplex mode)
Date: Fri, 23 Jul 2004 08:47:28 +0000 [thread overview]
Message-ID: <cdqjku$68j$1@sea.gmane.org> (raw)
In-Reply-To: <loom.20040721T163210-958@post.gmane.org>
<carlsonj@workingcode.com> wrote in message
news:16638.36676.350168.813237@carlson.workingcode.com...
> Simon Chow writes:
> > I am researching how to handle the AT packets and Data packets offered
by
> > the Wavecom GSM modem in AT+WMUX=1 mode. I want to modify the pppd
programme
> > and I think that the tty.c in pppd may be the key to change. The
charshunt
> > function manipulates both the raw bytes sent from and received by the
serial
> > port. However, I am still in an initial stage.
>
> I don't think that analysis is right. The charshunt task is invoked
> only in a few cases (e.g., where the 'record', 'notty', or 'socket'
> options are used), and isn't the normal data path. The normal data
> path is in the kernel, not user space.
>
> > I wonder if the pppd tool can handle the multiplex mode offered by
Wavecom
> > GSM modem. Thanks.
>
> Not today. I think you'd have to modify the PPP modules in the Linux
> kernel to detect the switching mechanism and feed the data up to pppd
> first. Otherwise, it'll probably be handled as bad PPP frames and
> discarded.
>
> --
> James Carlson <carlsonj@workingcode.com>
> -
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>
How about I modify the ppp_async_input function in ppp_async.c to detect the
0xAA and 0xDD, and the ppp_async_push function to encapsulate the PPP frame
with 0xDD?
prev parent reply other threads:[~2004-07-23 8:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-21 14:33 pppd and AT+WMUX(Multiplex mode) Simon Chow
2004-07-21 15:44 ` carlsonj
2004-07-22 9:11 ` Miguel-Munoz
2004-07-23 8:47 ` Simon Chow [this message]
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