VoIP Mailing List Archives

[rob at hillis.dyndns.org]

I'd say "consider yourself very lucky". I know I did some testing here
some time ago with faxing over VoIP.

* One extension to another over G711a with both extensions on the
same LAN - worked 95% of the time
* One extension on my Asterisk server to an Extension on a friend's
Asterisk server using G711a via IAX - 95% failure rate. Both of
us awere on the same ISP and had ping times of ~40ms between us.

However, in a live environment, I convert a PSTN call to a t.38 encoded
call and can send the fax just about anywhere I damn well want (where
the remote end supports t.3 with a 95% success rate.

t.38 is the key to successful faxing over a VoIP network. Without it,
you're begging for trouble.
Doug Lytle wrote:

[jonnt at taylortelepho...]

NOT true and I have proven that for the last year.



Jonn



_____

From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Rob Hillis
Sent: Tuesday, January 01, 2008 4:13 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Asterisk 1.4 Fax



I'd say "consider yourself very lucky". I know I did some testing here some time ago with faxing over VoIP.

* One extension to another over G711a with both extensions on the same LAN - worked 95% of the time
* One extension on my Asterisk server to an Extension on a friend's Asterisk server using G711a via IAX - 95% failure rate. Both of us awere on the same ISP and had ping times of ~40ms between us.

However, in a live environment, I convert a PSTN call to a t.38 encoded call and can send the fax just about anywhere I damn well want (where the remote end supports t.3 with a 95% success rate.

t.38 is the key to successful faxing over a VoIP network. Without it, you're begging for trouble.
Doug Lytle wrote:

Jonn R Taylor wrote:


If I had ANY failed faxes I would here about it. Iaxmodem creates a log of its own, so when I get a connection that fails hylafax sends the failure to me. One of the things that I found is you need to add nojitterbuffer to the iaxmodem config file,



Really? I'll have to do some testing, I've never tried since I've read
you can't.

Doug





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[support at drdos.info]

Jonn R Taylor wrote:

[steveu at coppice.org]

Jonn R Taylor wrote:

[asteriskal at gmail.com]

Guys!
what i was looking here was a simple hint/recommendation for installing
IaxModem and Hylafax.
Let me try it myself and see how feasible this solutions is.
On Jan 1, 2008 5:02 PM, Steve Underwood <steveu at coppice.org> wrote:

[jonnt at taylortelepho...]

Steve,

One of the main reasons that this works is controlling the data to and from the internet. I have spent the last 10 years building networks for ISP's. The key is getting the data from point a to point b in tact and in order.

I did not get "lucky" as you put it. I am a network engineer and I know how to make networks work the way they need to.

Jonn

-----Original Message-----
From: asterisk-users-bounces at lists.digium.com [mailto:asterisk-users-bounces at lists.digium.com] On Behalf Of Steve Underwood
Sent: Tuesday, January 01, 2008 6:02 PM
To: Asterisk Users Mailing List - Non-Commercial Discussion
Subject: Re: [asterisk-users] Asterisk 1.4 Fax

Jonn R Taylor wrote:

[rob at hillis.dyndns.org]

I think perhaps you are the exception rather than the rule.

Maybe you were able to engineer your network so that fax works without
any of the FoIP protocols - good luck to you if you have. For /most/
people, it's unlikely they would have sufficient control over their WAN
segment to ensure that it is sufficiently fast and reliable enough for
fax to work reliably.

In any case, why on earth would you attempt to re-invent the wheel?
T.38 is not only considerably more reliable and robust, it's nowhere
/near/ as bandwidth intensive as G711.

The original question was regarding using IAXmodem and Hylafax to
receive faxes over a SIP connection. Given that T.38 can not work in
this situation, the simple answer is that it /isn't/ the best solution.
Jonn R Taylor wrote:

[norman at myasd.com]

On Jan 1, 2008, at 1:00 PM, asterisk-users-request at lists.digium.com
wrote:

[oza-4h07 at myamail.com]

Hello,

2008/1/1, Steve Underwood <steveu at coppice.org>: