AudioCodes 420HD - Configuring DTMF; Figure 18-5: Web Interface - DTMF Transport Mode; Table 18-4: DTMF Transport Mode

400HD Series IP Phones
Administrator's Manual 114 Document #: LTRT-11950
18.4 Configuring DTMF
Dual-Tone Multi-Frequency (DTMF) signaling can be configured using the Web interface or
Configuration File.
 To configure DTMF using the Web interface:
1. Access the Dialing page (Configuration tab > Voice Over IP menu > Dialing).
Figure 18-5: Web Interface - DTMF Transport Mode
2. You can choose one of three available DTMF transport methods:
3. The Web interface allows selecting Inband, RFC 2833, or Via SIP as the DTMF
transport type.
4. Configure the parameter using the table below as reference, and then click Submit.
 To configure DTMF using the Configuration File:
• Use the table below as reference.
Table 18-4: DTMF Transport Mode
Parameter Description
DTMF Transport Mode
[voip/media/out_of_band_dtmf]
DTMF transport mode.
 [INBAND] Inband
 [RFC2833] RFC 2833 (default)

[VIA_SIP]
Via SIP
[voip/media/dtmf_via_sip_force_flag]
Must be set to 1 to enable Via SIP as DTMF transport type.
Note:
• The Web interface parameter 'DTMF Transport Mode' and the cfg file parameter
'voip/media/out_of_band_dtmf' are related; changing one changes the other.
• If the cfg file parameter 'voip/media/dtmf_via_sip_force_flag' is enabled, a SIP
message is sent in addition to the RTP message. If it is disabled, only one message is
sent, according to the selected DTMF transport type.