SAP BCM - Contact Centre 7.0.6 New Gateway connected. But outbound DTMF tones not working

[former_member597436]

Just installed a new PSTN gateway.  Set up using UDP.  with G711u codec.

when we make external calls, and press DTMF digits using CDT dial pad.  the tones appear to go to line as the recipient hears the tones, but the action disables outbound audio and the call drops.  So it appears DTMF is sent but it breaks the call.

gateway is a SONUS SBC2000 which has another SIP connection for Lync users.  DTMF works as expected for Lync users.

[former_member202106 · Accepted solution]

Hi Kevin,

If I remember right Sonus gateways are desined for MS Lync and the gateway supports only RFC2833 method for sending DTMF tones. And btw Sonus gateways are not listed in SAP Contact Center CL list.

By default SAP Contact Center uses SIP info method to send the DTMF tones. Now if Sonus doesn't understand SIP info it could disconnect the call. So, I recommend you to read about SIP info and RFC2833 for example from application help under System Configurator - Call Switching - Managing Trunks. (could not copy paste public link for some reason...)

Next steps would be to investigate who disconnects the call if playing around with DTMF settings doesnt help. There you have two options:
1. Sonus trace, check from Sonus logs what happens
2. SAP Contact Center Call Dispatcher log (CD)

Regards,
Jukka
SAP Contact Center team

[former_member597436 · Accepted solution]

Thankyou all,

In the end this was resolved with installing a firmware update on the Sonus.

We were running ver 4.1.0 and we updated to 4.1.1 which resolved the bug.

[Former Member]

Hi Kevin,

I had the same problem, for example in audiocodes we change the parameter:

Protocol management->Protocol Definition->1st TX DTMF option->Not Supported.

Regards,

Juan Carlos