[asterisk-users] DTMF not recognized on ISDN with Siemens -not IP- phone

[Gordon Henderson]

On Wed, 28 Nov 2007, Administrator TOOTAI wrote:

> Good day all,
>
> we have following setup: Debian Etch 64, Asterisk SVN-branch-1.4-r66244
> with mISDN 1.1.3 and 2 Digium cards B410P. Our customers calls in the
> office through ISDN lines and then get a possibility to join meetme
> conference. It works well except when customers are using SIEMENS phones
> (not IP): DTMF is not recognized.
>
> Does someone have an idea on what could be the problem with those phones?

Have you tried fiddling with the DTMF settings in the mISDN config file?

   dtmfthreshold=50

in /etc/misdn-init.conf..

It defaults to 100 and I had an issue with one site where if people called 
in on a mobile phone it was fine, but if they called in from an analogue 
land-line it wouldn't detect tones until I dropped it to 50.

Gordon