[Asterisk-Users] Fail to detect DTMF over direct ISDN pri link

[Peter Svensson]

On Tue, 15 Feb 2005, Sylvain Gagnon wrote:

> I'm using Asterisk (latest CVS head) to perform outbound call as
> robot/testing tool for an IVR platform, with a Wildcard T100P configure as
> ISDN Pri.
> For develop the exten context script I was using a real PSTN ISDN Megalink
> (DMS100) to reach the platform and my script was able to correctly detected
> the DTMF tone send back by the platform to synchronize the script.
> But for load test, I want to used a direct ISDN link with the platform,
> without to change anything at the Asterix side, I configure the platform to
> be the ISDN Network side (DMS100) with a twist cable. The D-Channel can up;
> I am able to perform call, except Asterisk doesn't detect any DTMF anymore?
> Why? What is the relation with the ISDN link?
> I use the "monitor" command to record the call, and I really hear the DTMF
> tone correctly...
> I try to put relaxdtmf=yes in the Zapata.conf, but no success....
> Thanks for any help or suggestion to diagnose this problem.

I'm not quite sure I understand your setup when the dtmf detection works / 
does not work. Can you explain what is connected to what for the two 
cases?

One possibility I can think of is that inband digits are not detected on a 
PRI until the call is in the PROCEEDING phase. Until then the digits are 
dent as INFORMATION elements. Perhaps your two pieces of equipment do not 
agreee on the state of the call?

Peter