Re: Fax and VoIP

Al <e@aa.invalid> 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

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" <abuse@dopiaza.cabal.org.uk> wrote in message
news:42dd70ab$0$30800$db0fefd9@news.zen.co.uk...
> Al <e@aa.invalid> 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