Fax connect speeds

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Hi,

On Sun, Dec 06, 1998 at 04:17:51PM +0000, Michael Van Donselaar wrote:
> >> 12/05 22:37:14 yS1  fax_id: '+FTSI: "          4024671707"'
> >> 12/05 22:37:15 yS1  transmission par.: '+FDCS: 0,0,0,0,0,0,0,5'** found **
> >
> >The modem reports back something that doesn't really make sense - normal
> >mode, 2400 bps, but MUCH delay for every scan line in the fax.
> 
> Could you point me to some docs explaining this line?  

The details are in the class 2 (.0) standard.  Most important, though, are
the first two digits: resolution (0=normal, 1=fine) and speed (0=2400,
1=4800, 2=7200, ..., 5=14400) and the last digit (milliseconds per scan
line, for slow paper fax machines that can't do buffering).

> Is this the exact info sent by the sending fax, or the results agreed 
> upon after negotiation?  If it is the exact info, then I KNOW that my
> *%$*$* Atlas modem is mangling it:  The fax is capable of at least 9600.

That's what the sending modem negotiated with your side - the sender tries
different speeds, based on what your modem tells it ("I can do 9600" -
"ok, let's try 9600 first, then step down to 7200/4800/2400 if it doesn't
work").  So if your modem advertises crap, or can't really accept higher
speeds than 2400, negotiation will step down to 2400.  To know more, one
would have to "listen into the line", as the class 2 interface doesn't
provide more data.

gert
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Gert Doering - Munich, Germany                             gert@greenie.muc.de
fax: +49-89-35655025                        gert.doering@physik.tu-muenchen.de