DTMF does not work via SIP

[POOLman1984]

Hi,

Basic call works fine, but does not work extension dial number (DTMF).

Here's my scheme connections:

                         SIP                                   H.323

SIP Provider <-------------->GW(Cisco2821)<-------------->CUCM8.5.1

Router configuration (see attachment).

Any ideas?

[clileikis]

Hi there,

Try running a 'debug voip dial-peer' and make sure that you're not matching dial-peer 0 which has DTMF relay disabled.

HTH,

Chris

[Tommer Catlin]

Do you have any MTPs defined. I see on the router, there are none.      

[james.ferris]

Here is some info on DTMF and SIP that may help.

http://www.cisco.com/en/US/docs/ios/12_3/sip/configuration/guide/chapter8.html

[Tapan Dutt]

Hi

Try forcing RFC 2833 or OOB DTMF on the SIP trunk pointing to the SP, dont use no preference option.

HTH

Tapan

[POOLman1984]

SP requires RFC 3261, DTMF in-band.

[stavros]

First you need to decide how you want to transmit DTMF, be it in band or out of band. I think that out of band is best for voip. The most common way is to use rfc2833 (rtp-nte in cisco world).

You need to run a sip trace "debug ccsip messages" and look at what is being negotiated.

[POOLman1984]

Clear requirements for the Provider:

RFC3261

DTMF in-band

codec G711a

Someone can describe the hardware setup step by step: Gateway, CUCM?

My brain is boiling ........

[Chad Stachowicz]

Hello,

   Can you tell me is it inbound or outbound DTMF that is not working.. or both.  From there I can help you.

Chad

[Rui Coelho]

Hi there,

anyone able to put it to work? I have the same problem with my service provider, which only supports inband voice dtmf

best regards

[stavros]

I would say you need to remove "dtmf-relay rtp-nte h245-alphanumeric" from your dial-peers.

Stavros