Re: [hylafax-users] Faxing over VOIP?

["Rob Rothberg" <rrothberg@xxxxxxxxx>]

On 11/10/06, Jamin W. Collins <jcollins@xxxxxxxxxxxxxxxx> wrote:

Rob Rothberg wrote:
> Am I missing something here?  One has zero control of the jitter
> involved over the VoIP connection between the ISP that Asterisk is
> sitting on and POTS.

You can use iaxmodem, Asterisk, and Hylafax without needing an ISP.
This does not mean that you have to have physical TDM lines coming into
the Asterisk system nor does it preclude it.  For instance take the
following scenarios:

1) TDM line from the Central Office terminates on a TDM to SIP
conversion device.  SIP communication travels over a local private
network to the Asterisk box.  Asterisk then delivers the call to an
iaxmodem client on yet another box, controlled by Hylafax, over the
local private network.

2) TDM line from the Central Office terminates into an Asterisk box.
Asterisk then delivers the call to an iaxmodem client running locally
controlled by Hylafax.

Neither of these scenarios involve a VoIP connection between the ISP and
Asterisk.  Even if they did, as long as that connection supported T.38
end to end, the inside leg could still be constructed as illustrated above.

--
Jamin W. Collins

The subject of this thread is Faxing over VoIP.  Thus the only scenarios
I am discussing traverse a VoIP link and that's where the jitter issue
arises.  T.38 may or may not be supported end to end, obviously with
some research you can try to find a VoIP provider who reliably offers
T.38 but they may hand off to someone who doesn't.

All I'm trying to say is faxing over VoIP may very well work most of the time.... 
but you shouldn't absolutely count on it working if your business needs require it to 
work 100% reliably.  In fact I'm in the process of testing this via a couple of
different VoIP providers.  Over the next week or two, II will be sending out 1000 
one page faxes over a couple of different VoIP providers via IAXmodem to see
just how many arrive.  Maybe it will even be 1000 but somehow I doubt it.