[Asterisk-Users] SIP UA Fax device

[Alex Lopez]

How does Vonage do it??

-----Original Message-----
From: Simon Woodhead [mailto:woodheads at gonegardening.com] 
Sent: Thursday, May 22, 2003 2:01 PM
To: asterisk-users at lists.digium.com
Subject: Re: [Asterisk-Users] SIP UA Fax device

Hi Dan,

If you find one please let me know although we've had no success looking
for
such a thing ourselves. Our experience to date in looking might be of
some
use to you though...

We're trying to replace BRI lines with a H.323 connection to a telco
over
our leased line. Faxes remain one of the problem areas. Logic says that
since faxes and modem were designed to send data over existing analogue
voice channels that it should be possible to send them over VoIP
channels
but searching the archives for this list and elsewhere suggests
otherwise.
Apparently because the data is being modulated and then demodulated
repeatedly through the various layers and VoIP is lossy it won't work.
The
solution seems to be T.38 fax relay although asterisk doesn't support
it.

We're playing with Hylafax (www.hylafax.org), an open source fax server.
You
might get lucky asking around there for SIP support but to my knowledge
it
only supports hardware modems. For us, we're looking at setting up
asterisk
extensions on a TDM-400P and then looping a physical wire into fax
modems on
a neighbouring machine. We've tested this with * dialling out and
answering
existing ISDN channels and forwarding to/from a normal fax machine and
it
works perfectly.

IP wise, as I mentioned, we want to ditch the ISDN and use our H.323
connection. We have two *s in different countries talking to each other
by
IAX. Despite what the archives say, we have been able to send faxes from
analogue fax machines connected at each end (or dialling in/out to one
end)
over a voice channel in between with no problems at all. We haven't
tried
over the H.323. yet but will be doing so shortly.

I don't know which side of * you need the SIP connection but what works
over
the net shouldn't struggle on a LAN. On the basis of our limited
experience
so far, IP to outside seems to work fine and LANside you can either
physically connect a fax modem to * or hook up something like an ATA186
to a
fax machine/fax-modem.

I hope this is of some help and look forward to hearing how you get on.

Cheers,
Simon

----- Original Message ----- 
From: "Dan" <dtoma at fx.ro>
To: <asterisk-users at lists.digium.com>
Sent: Thursday, May 22, 2003 9:10 AM
Subject: [Asterisk-Users] SIP UA Fax device


> Hi,
>
> Anyone knows a software fax device which can act as a SIP UA?
> I want to have a SIP based FAX machine (sofware) on a PC associated
with
an
> Asterisk extension.
>
> Thanks,
> Dan
>
>
> _______________________________________________
> Asterisk-Users mailing list
> Asterisk-Users at lists.digium.com
> http://lists.digium.com/mailman/listinfo/asterisk-users
>


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