Duplicate DTMF signals being sent

[Joseph56]

Hi we're having issues with DTMF signals being sent mutiple times are shown below.


Is there anything that can be configured to stop this? As on the keypad only 074 was dialled

 

[VasilisV_3CX]

Hi @Joseph56,

This is normal, what problem is this causing that you'd like to remedy by reducing the DTMF signal count?

 

[Joseph56]

Hi Vasilis,
thank you for confirming this is normal. we are having issues with PCI pal, where when they receive the DTMF signal it is showing in the incorrect order.

Gamma (our sip provider) has said this is an issue due to the DTMF being sent multiple times.

 

[VasilisV_3CX]

Hi @Joseph56,

Can you provide me with a typical scenario to understand how this is done?

For example, does a user in the office dial the payment gateway and start entering numbers? What device are they using to enter the numbers?

In your captures are the numbers showing in the correct order?

 

[Joseph56]

Hi Vasilis,
the user dials a quick code 3333 which dials our PCI PAL number.
The user then hears a been and dials the number they will to dial via the payment gateway.
The phone will then dial the end customer via the payment gateway.

The phone we are using in the 3CX softphone, and 3CX softphone in the browser.

The DTMF codes are in the correct order but duplicated outbound. but are scrambled inbound at the payment gateway.


Inbound Payment Gateway

 

[VasilisV_3CX]

Hi @Joseph56,

Can you send me the full capture in a PM? What you're sending is not at all out of the ordinary as outlined in RFC 2833.

 

[VasilisV_3CX]

What seemed to happen was an issue with the upstream provider when DTMF tones were sent in quick succession. By spacing the inputs by 1 - 2 seconds, the issue did not occur. This will need to be investigated with @Joseph56's provider.