This is not an issue; it's a feature not supported by 3CX ; Conference calls (via the conference extension, aka 700) do not transmit DTMF tones.
DTMF works with conferences made using your deskphones because the conference is managed by the phone itself, not by 3CX. Therefore, we could call it a '3-way conference.' During a conference held with your desk phone, if you hang up, all participants will lose the connection, and the call will end for everyone. In contrast, with a 3CX conference, the other participants remain connected even if the conference initiator hangs up.
Solution 1: Use a second line, make your call, enter the DTMF tones, and then merge the call into your conference.
Solution 2: Check with your SIP trunk provider to see if they support sending DTMF in the dialing string (in the same string as the dialed phone number).
For example,
Following numerous requests from their 3CX clients and 3CX partners/VoiceMeUp resellers, VoiceMeUp (Canada/USA) has developed this specific feature to address this particular scenario ( Is not a solution recognized by the RFC ) .
With VoiceMeUp as your trunk provider, you can dial 18006226232+dtmf+wW1234, and he will send the DTMF tones (1234) for you ;
- The code +dtmf+activates the function,
- ( The rest will be executed once the called party answers the call. )
- 'w' (lowercase) represents a wait time of 0.5 seconds.
- 'W' (uppercase) represents a wait time of 1 second.
So, 18006226232+dtmf+
wW1234 ;
18006626232 .. phone number
wait answer ; When the call was answered.
w (lowercase) ; Pause for 0.5 seconds.
W (uppercase) ; Pause for 1 seconds.
(total pause = 1.5 seconds)
1234 ; Send automatically DTMF 1 2 3 4
It’s convenient for softphones on computers but less user-friendly for desk phones but as explained, the desk phones manage their own conferences.
Check with Telnyx, you never know!
