Yealink VC400 Administrator's Manual page 150

Administrator's Guide for Yealink Video Conferencing Systems
Enter the desired value in the DTMF Payload Type(96~127) field.
4.
Click Confirm to accept the change.
5.
To configure DTMF type for SIP account via web user interface:
Click on Account->SIP Account.
1.
Select the desired value from the pull-down list of DTMF Type.
2.
If SIP INFO or RFC2833+ SIP INFO is selected, select the desired value from the
pull-down list of DTMF Info Type.
Enter the desired value in the DTMF Payload Type(96~127) field.
3.
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