# No DTMF detection on Asterisk originated zap outbound calls

**URL:** <https://community.asterisk.org/t/no-dtmf-detection-on-asterisk-originated-zap-outbound-calls/7641>\
**Category:** Asterisk Support\
**Created:** [July 9, 2006, 4:59pm UTC](https://community.asterisk.org/t/no-dtmf-detection-on-asterisk-originated-zap-outbound-calls/7641 "2006-07-09T16:59:49Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![roberth](https://avatars.discourse-cdn.com/v4/letter/r/8e8cbc/32.png) [@roberth](https://community.asterisk.org/u/roberth)\
**Post date:** [July 9, 2006, 4:59pm UTC](https://community.asterisk.org/t/no-dtmf-detection-on-asterisk-originated-zap-outbound-calls/7641/1 "2006-07-09T16:59:49Z")

</div>

Hi,  
I have a callback application that creates a call file and drops it into the  
/var/spool/asterisk/outgoing directory. This file places a call and  
goes to a DISA context when the call has been answered.

This works perfectly over SIP phones but does not work on my ISDN PRIs  
(neither Digium TE210P nor TE205P card) both connected  
to german t-com e1 (in Germany called S2M) trunks.

If I dial IN to the same context, DTMF is detected fine but if Asterisk originates the call, DTMF is not recognized.

This happens on all phones that receive calls (not only mobile phones).  
One strange thing here:  
On 1 of about 20 tries DTMF recognition works fine when Asterisk dials out.  
In this case I can see the debug message

Jul 9 16:58:29 NOTICE[3871]: channel.c:2424 \_\_ast\_request\_and\_dial: Don’t know what to do with control frame 15

When this message appears DTMF tones will be detected

I’m using all latest versions from digium  
asterisk-1.2.9.1  
libpri-1.2.3  
zaptel-1.2.6

all compiled and running on a HP Proliant 3GHz Xeon Server with  
Debian Sarge and Kernel 2.6.8-3-686-smp i686

Things I have already tried that did not solve the problem until now:

- changed relaxdtmf to yes and no in /etc/asterisk/zapata.conf
- changed callprogress=no to yes in /etc/asterisk/zapata.conf
- changed ‘static int vpmdtmfsupport = 1;’ to ‘0;’ in /usr/src/zaptel-1.2.6/wct4xxp.c and then  
recompile zaptel drivers and asterisk (like mentioned in digium kb)
- using a own context with background() and WaitExten() instead of DISA Application

In Newsgroups and the internet I also can’t find any problem solution for that  
(you will find some problem descriptions with the same problem but no solution for that)

Does anyone have the same problem or anyone have ideas how to solve this issue?

Thanks a lot,  
Robert