DTMF tones in a conference

[SweetAction]

Looking for someone to test something for me....

Environment:
3CX V16 Ent Update 2 (PBX was built fresh at update 1 and no backup restored, so really fresh)
Windows Softphone client (Also tried with Yealink T4x using the client in CTI mode)
Flowroute SIP provider

Situation
Call a location with an IVR. Input via key (press 1, etc) - no issues. System accepts it, move through the menus, etc
Convert call to conference and bring in someone else. Input via key (press 1, etc) - now does nothing. It's like the DTMF tones are not being sent, although pressing buttons makes noise.

Anyone able to replicate this?

 

[JohnS_3CX]

Hi @SweetAction

This is not supported. The reason this does not work is because we capture the DTMF when in conference mode. You hear it in your device but it is not transmitted to the other parties.

So if you are going to use conference mode, this will not allow DTMF to pass through but depending on what you are trying to achieve there might be other ways.

 

[SweetAction]

Hi @JohnS_3CX
Thanks for confirmation of this.

If I am in a call with a person and need to conference in someone else who is behind an IVR (for example they have no DID), how can I do this?

 

[JohnS_3CX]

1. you have to go on hold, and now start a new call
2. navigate through the IVR until you reach your person
3. once you reach the person, transfer them to the conference extension
4. resume your original call with the conference and everyone should be there now

 

[SweetAction]

1. you have to go on hold, and now start a new call
2. navigate through the IVR until you reach your person
3. once you reach the person, transfer them to the conference extension
4. resume your original call with the conference and everyone should be there now

Just tested and it did work, however it's a slightly convoluted process.

Is there other way to get DTMF to work in a conference?

 

[SweetAction]

I did some digging around. Can someone confirm this:

When a single person makes a call, the extension settings of DTMF RFC2833 is used. However, when using the conf (700) number, all DTMF is sent as inband instead.

Is there a setting to have 700 send it as RFC2833 instead?