DTMF masking for agents in conference call

I have a scenario where Caller A is calling an Agent and Agent is further transferring call to IVR(Caller B).
While caller A is entering card information for payment , those DTMF tones should not be audible to the Agent. But those should be received as it is on the IVR end.
I tried this scenario using confbridge.conf dtmf_passthrough=no configuration but it is not working.

Any suggestions how can we achieve this.

You can’t both be transferring to the IVR and in conference with the IVR. I think you are using transfer loosely. Please clarify.

Even if the DTMF isn’t nominally in band, I suspect that some will leak through before the upstream system realises a digit is being sent. I’d therefore say that you need to completely remove the agent whilst the IVR is in progress.

No Agent is in the call so basically its conference . The only thing required while credit card number is entered the agent should not hear the DTMF tones even. I need to suppress those tones for agent and those should be received at IVR end as it is.

I’m confused.

It might be possible to use a feature code to temporarily connect the caller to the IVR, although there are some questions about whether you can do this for a conference (in which case you will need an unoptimised local channel, ahead of it), and whether you can bridge a call to something else during the execution of a feature.

I’m not sure whether you are using in band, in which case there is no need to pass through the DTMF, as it will do so automatically, or whether you are hearing the starting transients of the tone, before they are recognized as being tones, but in general, I don’t think PCI DSS would accept any solution in which individual tones are muted. I think it would want a transition to private communication and a positive confirmation of that.

I am rephrasing my question . Caller A is calling to Agent and he is further connecting to caller B which is IVR. credit card information needs to be received from caller A to Caller B. Agent is there in the conference but for PCI DSS compliance , I dont want agent to hear the DTMF tones which would be entered by caller A while entering credit card or any sensitive information.
So either i need to mask those or need to get those tones muted.
DTMFMODE used is auto in my case.

As I said, you can’t do this digit by digit; you have to turn off the audio to the everything but the IVR for the whole of the DTMF sequence. If you don’t some initial transients are going to leak through, and, with the right equipment, it may be possible to recover the the digits.

Have you tried to see if a feature code can take you to the IVR. If you cannot use features in the conference bridge, you may still be able to use an, unoptimised, local channel ahead of it. The only remaining concern is whether feature processing can create a temporary bridge.