[Asterisk-Users] DTMF modes and external IVR systems over ISDN

[Stefano Finetti]

Hello,

I'm trying to understand why when I make a call from a SIP phone to an
external number who has an IVR system in which I've to choose some options
using the dialpad, it does'nt recognise the key pressed and remains still
waiting for my choose.

I'm tryng using Grandstream 102, and i've tryed with all the 3 modes
possibile:

Dtmf inband, rfc2833 and INFO (obviously configuring'em also in sip.conf).

I think that's a problem of the ISDN line (used with I4L modem drivers),
that does'nt pass the DTMF to the end point of the call.

Is there some thing i can do on the conf files or I have to search the
answer into the source tree?

I googlized a bit and found some patch to isdn_tty (that should solve the
problem of receiving dtmf from isdn line when calling with a person), but
unfortunately, the kernel version is different and also correcting a bit the
patch, it doesn't work for me - i still get errors with patch.

Nothing found for the contrary use: sending dtmf over the isdn to make
possibile a choice into an external ivr or menu system.

Any link/patch/suggestion?

Without it, my * box will be soon cut off by my boss (i need to set-up our
pbx ASAP - prior to holidays... :( )

-- 
Stefano Finetti