Calling to an IVR via ISDN

[giovanni.v]

Setup:

-------------------------------------------------------------------------------------------
[SIP Phone]<-->[AskoziaPBX|BN4S0]<-->[Telco ISDN BRI]

OR

[ISDN PBX]<-->[NT/BN4S0|AskoziaPBX|BN4S0/TE]<-->[Telco ISDN BRI]
-------------------------------------------------------------------------------------------

- SIP phone DTMF mode set to "SIP info" or RFC2833.
- Call a PSTN number where answer an interactive voice response system via ISDN.

Now dialling any digits does nothing, no DTMF tone passed to network. also no events in the Asterisk console.

Someone can confirm this?
Calling via a SIP provider works, the called number receive DTMF.

Setting "dtmf_generate=yes" in capi.conf (using advanced/manual attributes) works... but the isdn4bsd readme says:

;dtmf_generate=yes ; set this if your [SIP] phone does not generate
                   ; inband DTMF tones. It is not recommended to
                   ; enable this. You should configure your [SIP] phone
                   ; to generate both inband DTMF and SIP INFO.

I consider Inband DTMF the latest resort, but according to h.p.s. SIP INFO should work, but don't.

[macafee]

I have this problem,too.

[josepedro]

I had this problem too. I have one of Askozia Shop's appliances (IP+ISDN) and this happens with this hardware too.
The only way to solve it is adding the "dtmf_generate=yes" parameter in each ISDN interface, as Giovanni says. The easiest way to do this in the web interface is going to System > Interfaces > ISDN, edit one of your interfaces and press "show" in "Advanced Settings". In "Manual Attributes" you can add   dtmf_generate=yes   and this works fine. Also, it is very good that this is saved in your configuration file so if you reboot, backup or restore your configuration, this setting will stay there.