Passing through DTMF for PCI credit cards calls

[chriselectrix]

Hi

In order to be PCI compliant use a company to handle our 'credit card over the phone' payments.

1) Call comes in to 3CX agent.
2) When the card details need to be taken, the agent blind transfers the call to our PCI provider who instantly transfer the call back to the agent on their DDI.
3) The incoming call is now looped through our 3CX system, out to the PCI provider and back into our 3CX system (using 3 lines?).
4) The agent asks the caller to enter their card number - because the call is routing through our PCI provider's network, they capture the key pressed (DTMF) and are able to capture the callers' card details securely whilst supressing the DTMF tones.
5) Our agent can see on their PCI portal as the card holder is typing their digits (seeing **** **** **** **** etc)

We regularly have an issue where our PCI provider isn't able to capture all digits that the caller enters. It might miss 2 or 3 digits. This doesn't happen every time (maybe 1 in 6).

Our PCI provider has told us on numerous occasions that we are their only customer facing these issues.

The issue only started happening when we switched to 3CX (which is a great system so don't think I am knocking it - I am regularly recommending it to others). The only other thing that changed was the lines are now on the Gamma (Horizon - UK) network.

Our support company have spent a long time investigating the issue but are unable to get anywhere with it. They have told me the system is set to Out Of Band for the DTMF tones, but its not clear whether this affect all legs of the call (?). Bearing in mind the caller is coming into our system and back out to the PCI gateway, then back in to the agent.

Our PCI provider have sent us call recordings from their Horizon system, and when there are key presses the DTMF is a short 'bip' (fraction of a second). Compared to the DTMFs that are coming from our 3CX via Gamma which are longer and more 'crackly/distorted'. I'm fairly confident that it could just be simply a setting somewhere deep in 3CX that is causing this.

I would love to be able to pin point the issue, whether it be a 3CX setting, Gamma, our PCI provider or somewhere in between.

We are on the latest version but the issue was still present in V16.

Any help or suggestions would be greatly appreciated.

Is anyone else using a similar provider? If so, are you facing any issues with DTMF?

Thanks

 

[Alphabetic]

Im not sure if this would be a 3CX issue, the fact it works sometimes and not others - I would expect it works or doesnt if it was 3CX.

You said it worked before but you've changed PBX and SIP provider.

You and your PCI provider are going to need to troubleshoot further at a network level to see what's going on.

PS - update to v18.

 

[chriselectrix]

Thanks for your reply.

That's what I feared.

Our PCI provider can only tell us what is coming in to them.

Our line provider are can only tell us so much information then won't assist any further. There is also red tape around data protection etc which they can't give us access to.

We also configured 3CX to use a backup trunk (not Gamma) for the PCI calls but had the same issues (although the original calls would have still been coming through Gamma).

 

[Alphabetic]

You're going to need to work with the PCI provider support and make test calls.

From both ends you need network captures to see the DTMF sending and compare it to whats received.

you'll need to perform the test until you replicate.

 

[chriselectrix]

We have spent weeks doing these tests and capturing results. Somewhere along the line the DTMFs are getting messed up.

Will keep trying.