[Freeswitch-users] mod_openzap, sangoma, FAX and HW-HEC

Krzysztof Drewicz krzysztofdrewicz at gmail.com
Fri May 14 02:31:36 PDT 2010

2010/5/14 Helmut Kuper <helmut.kuper at ewetel.de>:
> Hello Moises,
> thx. Well I saw a hint for noise reduction capabilities of A104d
> somewhere in the logs during debugging. And it's easy to suppose that
> fax data could be interpreted as noise. On the other hand I'm a bit
> confused because the Fax is transmitted in a digital way, so where
> should the noise comes from (except the quantization noise).

Noise could come from analog line "on the other side", for example
this is 2 phones (one being facsimile machine) put in parallel to one
pair of copper line.
I run some big faxserver farm (like having 20+ channels up most of the
9-17 on one machine and having two machines in two different
locations)  and prefer to use some openvox cards without any EC
(hardware or software). with A102d i had some problems that caused
need to reboot server with a reset button every two-three weeks.

btw: i use dedicated machine just for faxing, for you disable 'on
demant' might work better.

what software you use for fax? (iaxmodem/ t38modem + hylafax or you do
faxes in FS ?) and what speed you manage to get (14 400 bps or some

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