[asterisk-users] how to set iaxmodem receiving speed

[Andrew Furey]

On 17 May 2012 22:40, gincantalupo <gincantalupo at fgasoftware.com> wrote:
> That could seem counter-intuitive but it is not. Not to mention the fact
> that information technology is not science, the solution to broken faxes is
> to lower down speed. This works even with normal telco lines even if you DO
> NOT have a pbx (telco technicians even say not to make faxes pass thru your
> PBX). I could ask my customer's telco to lower the speed down but it depends
> on the guy working at the call-center...sometime you talk to dummy people
> who ARE sure it is impossible. But it is not. So, I do not want to spend
> days to convince people working at that telco call-center that what I'm
> asking is feasible and I do not want to tell my customer to tell their
> customer to lower their faxes speed (before installing our PBX they were
> able to send perfect faxes so, why should they?).
>
> My idea was to tell iaxmodem not to accept fast speed rates so the fax
> machine on the other side should be forced to negotiate a slower speed as if
> my customer fax weren't virtual as iaxmodem is but a real one.
>
> I suspect that the problem is about the primary lines because I tested
> iaxmodem many times on my LAN and it is (surprisingly :) ) working fine (10
> good received faxes out of 10 sent!!!) but, as you may know, talking to
> telco technician is a nightmare....they always say problems are always on
> the PBX side... :(
>
> Moreover, after sending a fax, the fax machine beeps correctly as the fax
> was correctly sent without corruption. :o

And as a matching data point, we use ActiveFax for sending (interfaced
from an ERP package) and often get Comm Error 283 and incomplete
faxes. If it's just making a bad situation worse, how is it that our
solution of turning off ECM mode fixes it 98% of the time? I'm
curious. (We know it's fixed as often we're the receiver, and we can
see the correct fax come through.)

Sometimes we lower the speed too (to 9600) but often simply disabling
ECM is the solution.

Regards,
Andrew

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