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There's been some discussion here about sending fax through VoIP
telephone adaptors. The consensus view seems to be that this can be
hit and miss, so pretty unreliable.

What I haven't seen discussed very much about INCOMING fax to a fax
machine attached to an ATA. Is the situation for incoming fax much the
same as outgoing fax (ie problematic and unreliable) or is incoming
fax ok?

"Al" <> wrote in message
news:...
> There's been some discussion here about sending fax through VoIP
> telephone adaptors. The consensus view seems to be that this can be
> hit and miss, so pretty unreliable.
>
> What I haven't seen discussed very much about INCOMING fax to a fax
> machine attached to an ATA. Is the situation for incoming fax much the
> same as outgoing fax (ie problematic and unreliable) or is incoming
> fax ok?

Yes, the issue is with the quality of the connection. So yes it much
relates to both sending and receiving where VoIP is in any way connected.
That said, I have used a sipura ATA recently to send and receive fax without
a problem. It all depends in the codec in use on the service you use. The
fax issue is down to (normally) the amount of compression of the data
stream.

If you can try it, give it a go, you might just find its OK for you. It is
here (not that I use fax normally, but I did perform a test on both send and
receive recently, using sipgate as the provider of the VoIP service.

Tony

"Al" <> wrote in message
news:...
> There's been some discussion here about sending fax through VoIP
> telephone adaptors. The consensus view seems to be that this can be
> hit and miss, so pretty unreliable.
>
> What I haven't seen discussed very much about INCOMING fax to a fax
> machine attached to an ATA. Is the situation for incoming fax much the
> same as outgoing fax (ie problematic and unreliable) or is incoming
> fax ok?

Do you mean a fax sent from a PSTN line or from another VoIP line..? I
must admit I've never tried either, but if you or anyone want to do a test
(I'm on Sipgate) then let me know and I'll put a machine on line.

Ivor

On Tue, 19 Jul 2005 20:21:31 +0100, Tony wrote:

>Yes, the issue is with the quality of the connection. So yes it much
>relates to both sending and receiving where VoIP is in any way connected.
>That said, I have used a sipura ATA recently to send and receive fax without
>a problem. It all depends in the codec in use on the service you use. The
>fax issue is down to (normally) the amount of compression of the data
>stream.

Would you care to share with us your findings regarding use of codecs
with fax? Incidentally, I'm primarily interested fax to and from fixed
PSTN lines.

Al <> wrote:
> There's been some discussion here about sending fax through VoIP
> telephone adaptors. The consensus view seems to be that this can be
> hit and miss, so pretty unreliable.

I find that any sort of data (which includes fax) over VoIP on a BT
ADSL link is unreliable. OTOH, it works just fine if you're running
VoIP over an internal LAN, or over a high speed leased line.

(I've found practical uses for fax-over-VoIP on an intranet, so it's
not quite as silly as it first sounds.)

> What I haven't seen discussed very much about INCOMING fax to a fax
> machine attached to an ATA. Is the situation for incoming fax much
> the same as outgoing fax (ie problematic and unreliable) or is
> incoming fax ok?

The problem is related to the jitter once connected, so it doesn't
actually matter whether it's incoming or outgoing.

--
If your doctor warns that you have to watch your drinking, find a bar with a
mirror.
- John Mooney

"Al" <> wrote in message
news:...
> On Tue, 19 Jul 2005 20:21:31 +0100, Tony wrote:
>
> >Yes, the issue is with the quality of the connection. So yes it much
> >relates to both sending and receiving where VoIP is in any way connected.
> >That said, I have used a sipura ATA recently to send and receive fax
without
> >a problem. It all depends in the codec in use on the service you use.
The
> >fax issue is down to (normally) the amount of compression of the data
> >stream.
>
> Would you care to share with us your findings regarding use of codecs
> with fax? Incidentally, I'm primarily interested fax to and from fixed
> PSTN lines.

For reliable fax you need to use G711a codec and if possible limit the send
and recieve speed to 9600 and set your fax to accept more errors than it
normaly would before rejecting the page.

My fax server quite happly sits on a SIP port reciving faxes with no
problems, other than the odd black or white line. I very rarely send faxes
but the ones I do have always got through, I only have the server running as
a few customers send POs only by fax.

Ian

The encoding of voice patterns for digital transmission of data and that
used for voice are very different. Therefore, the ability of fax (image
data) to robustly encode on a voice line is somewhat limited and performance
drop not surprising.

You may want to consider a mixed voip and PSTN installation. You may use a
CLT to bridge between you Telco gear and the two ports, voip and pstn

Marco
http://cgi.ebay.com/ws/eBayISAPI.dll...MESE%3AIT&rd=1


"Peter Corlett" <> wrote in message
news:42dd70ab$0$30800$...
> Al <> wrote:
> > There's been some discussion here about sending fax through VoIP
> > telephone adaptors. The consensus view seems to be that this can be
> > hit and miss, so pretty unreliable.
>
> I find that any sort of data (which includes fax) over VoIP on a BT
> ADSL link is unreliable. OTOH, it works just fine if you're running
> VoIP over an internal LAN, or over a high speed leased line.
>
> (I've found practical uses for fax-over-VoIP on an intranet, so it's
> not quite as silly as it first sounds.)
>
> > What I haven't seen discussed very much about INCOMING fax to a fax
> > machine attached to an ATA. Is the situation for incoming fax much
> > the same as outgoing fax (ie problematic and unreliable) or is
> > incoming fax ok?
>
> The problem is related to the jitter once connected, so it doesn't
> actually matter whether it's incoming or outgoing.
>
> --
> If your doctor warns that you have to watch your drinking, find a bar with
a
> mirror.
> - John Mooney

Al

Is it possible to use the incomming bt line for fax and the ADSL on the same
physical telephone line for the broadband connection, then use the VoIP via
the broad band?
Is there any interferance between the Anologue fax and the ADSL data?

Andy
New to the group Hi All


"Al" <> wrote in message
news:...
> There's been some discussion here about sending fax through VoIP
> telephone adaptors. The consensus view seems to be that this can be
> hit and miss, so pretty unreliable.
>
> What I haven't seen discussed very much about INCOMING fax to a fax
> machine attached to an ATA. Is the situation for incoming fax much the
> same as outgoing fax (ie problematic and unreliable) or is incoming
> fax ok?

On Tue, 26 Jul 2005 22:41:19 +0100, Andy Evans wrote:

>Al
>
>Is it possible to use the incomming bt line for fax and the ADSL on the same
>physical telephone line for the broadband connection, then use the VoIP via
>the broad band?
>Is there any interferance between the Anologue fax and the ADSL data?

Yes, it's quite possible in theory to use my bt line for incoming fax.
However I use my bt line for voice only and I don't want to get
involved in doubling it up with fax and the attendant palaver.