[Asterisk-Users] DTMF not sending properly via IAX

[Rich Adamson]

Not sure this applies, but a few months ago some of us were having
problems with an itsp (livevoip.com) and incoming iax calls that 
hit the * ivr. dtmf was essentially not being passed. I opened a
bug, however Mark quickly closed it with a note "that's the way
iax works; have the itsp fix their problem".

The issue at that time was oriented around a call that was considered
"answered". If the end-to-end path of the call is considered answered,
asterisk is no longer in the voice path to translate dtmf into iax
out-of-band dtmf packets. Part of the argument was then "what is an 
asterisk user suppose to do to pass dtmf across an iax link that uses
g729"?  g729 won't reproduce the audio tones reliably, etc, etc.

Lurking behind all of that is a defacto telephony standard that
essentially supports dtmf end-to-end regardless of what type of circuit
is involved (dtmf passed in-band after answer). 

Is it possible that part of your issue might involve the answer status
of the iax path?

------------------------
> Hi Tony
>  
> I am having a similar issue to you - from the 'other' direction in that when I connect to * 
via IAX2 the DTMF is being ignored. I
> am running HEAD at the moment.
>  
> (and for the benefit of another subscriber so that they don't have to invoke their 
autoresponder I acknowlege that DTMF is
> sent out of band over IAX...)
>  
> http://bugs.digium.com/view.php?id=4631
>  
> Does this bear any relation?
>  
> Mark
>  
> On 7/12/05, Tony Mountifield <tony at softins.clara.co.uk> wrote:
> 
>     I'm not sure if this is a -users or a -dev question, since the answer
>     probably comes down to something in the code.
> 
>     I'm running the latest CVS-STABLE, and am subscribed to PSTN service
>     using IAX2 via Voiptalk in the UK.
> 
>     I've just been alerted by a customer that the sending of DTMF from my
>     asterisk box to a remote PSTN user doesn't work, although it used to.
> 
>     To test it, I have the following dialplan entries, that I can dial into:
> 
>     exten => s,1,Answer
>     exten => s,2,Wait(2)
>     exten => s,3,SendDTMF(1234567890)
>     exten => s,4,Wait(2)
>     exten => s,5,Hangup
> 
>     What happens is that whatever string I give to SendDTMF, I only hear the
>     first DTMF digit. The remaining digits don't get sent.
> 
>     I recently updated from an April CVS-STABLE to the July 4 version, but I
>     couldn't see any relevant differences in the code. As its a production
>     system, I can't just revert to test without planning.
> 
>     I don't know whether Voiptalk have changed anything.
> 
>     Is this a known bug in certain versions of Asterisk?
> 
>     If I do iax2 debug, I *can* see DTMF frames being sent and acked for
>     each digit. Wo I can't understand why I'm not hearing all the digits.
> 
>     Any ideas?
> 
>     Cheers
>     Tony