[asterisk-users] FFA SendFax rejects T.38 reINVITE (488 Not acceptable here)

[David Backeberg]

On Tue, Oct 19, 2010 at 11:21 AM, VoIP Question <voip.question at gmail.com> wrote:
> It's set to yes for this peer.
>
> also t38pt_udptl is set to yes.
>
> :(

You don't say anything about what you're trying to send / receive against.

Here's how you should troubleshoot:

* start with a 'real fax machine' if you have one, on an analog line
if you have one. If you can't receive / send with that against your
target, blame your target.
* move to audio-pass through fax on asterisk. No T.38. If that works.
* add in T.38

You will learn things in that process and be able to tell at what
layer your troubles are happening.

It could be coincidental that things give up during the reinvite. It
could actually be giving up for noise on the line, packet drops, etc.

At the very least, start recording the call. You'll at least be able
to hear up to the re-invite.

Definitely record the audio passthrough attempt and listen back to it.