DTMF (Dual Tone Multi-frequency) tone, better known as touch tone. DTMF is the signal sent from the IP phone to the network, which is generated when pressing the IP phone’s keypad during a call. Each key pressed on the IP phone generates one sinusoidal tone of two frequencies. One is generated from a high-frequency group and the other from a low-frequency group.

The following table lists the parameters you can use to configure the transmitting DTMF digit.

Parameter DBID_SIP_DTMF_MODE
Description It configures the DTMF type.
Permitted Values 0-INBAND, DTMF digits are transmitted in the voice band.
1-RFC2833, DTMF digits are transmitted by RTP Events compliant to RFC 2833.
2-SIP-INFO, DTMF digits are transmitted by the SIP INFO messages.
3-RFC2833 + SIP-INFO, DTMF digits are transmitted by RTP Events compliant to RFC 2833 and the SIP INFO messages.
Default 1
Web UI SIP Account > Line X [1] > Advanced > SIP Advanced Setup > DTMF Type
Parameter DBID_RFC_PAYLOAD
Description It configures the value of DTMF payload.
Note: It works only if “DBID_SIP_DTMF_MODE” is set to 1 (RFC2833) or 3 (RFC2833 + SIP INFO).
Permitted Values Integer larger than 96
Default 101
Web UI SIP Account > Line X [1] > Advanced > SIP Advanced Setup > RFC2833 Payload (>=96)

[1] X is the account ID. X = 1-4

Author：admin  Create time：2023-08-30 17:28
Last editor：admin  Update time：2023-12-22 13:50