Yealink SIP-T48G Administrator's Manual page 282

Administrator's Guide for SIP-T2_Series_T4_Series IP Phones
Details of Configuration Parameters:
account.X.dtmf.type
Description:
Configures the DTMF type for account X.
0-INBAND
1-RFC 2833
2-SIP INFO
3-RFC2833 + SIP INFO
If it is set to 0 (INBAND), DTMF digits are transmitted in the voice band.
If it is set to 1 (RFC 2833), DTMF digits are transmitted by RTP Events compliant to RFC
2833.
If it is set to 2 (SIP INFO), DTMF digits are transmitted by the SIP INFO messages.
If it is set to 3 (RFC2833 + SIP INFO), DTMF digits are transmitted by RTP Events
compliant to RFC 2833 and the SIP INFO messages.
X ranges from 1 to 16 (for SIP-T48G/T46G/T29G).
X ranges from 1 to 12 (for SIP-T42G).
X ranges from 1 to 6 (for SIP-T41P/T27P).
X ranges from 1 to 3 (for SIP-T23P/G).
X ranges from 1 to 2 (for SIP-T21(P) E2).
Web User Interface:
Account->Advanced->DTMF Type
Phone User Interface:
None
account.X.dtmf.dtmf_payload
Description:
Configures the RFC 2833 payload type for account X.
X ranges from 1 to 16 (for SIP-T48G/T46G/T29G).
X ranges from 1 to 12 (for SIP-T42G).
X ranges from 1 to 6 (for SIP-T41P/T27P).
X ranges from 1 to 3 (for SIP-T23P/G).
X ranges from 1 to 2 (for SIP-T21(P) E2).
Web User Interface:
268
Parameters Permitted Values Default
0, 1, 2 or 3
Integer from 96
101
to 127
1