Fax And Modem Capabilities; Fax/Modem Operating Modes - AudioCodes MediaPack MP-124 User Manual

Note that to set the RFC 2833 payload type with a different value (other than its
default, 96) configure the RFC2833PayloadType (RFC 2833 Payload Type)
parameter. The device negotiates the RFC 2833 payload type using local and remote
SDP and sends packets using the payload type from the received SDP. The device
expects to receive RFC 2833 packets with the same payload type as configured by
the RFC2833PayloadType parameter. If the remote side doesn't include 'telephony-
event' in its SDP, the device sends DTMF digits in transparent mode (as part of the
voice stream).
Sending DTMF digits (in RTP packets) as part of the audio stream (DTMF Relay
is disabled): This method is typically used with G.711 coders; with other low-bit rate
(LBR) coders, the quality of the DTMF digits is reduced. To enable this mode, define
the following:
•
RxDTMFOption = 0 (ini file); 'Declare RFC 2833 in SDP' field = 'No' (Web
interface -- refer to ''DTMF & Dialing Parameters'' on page 123)
•
TxDTMFOption = 0 (ini file); '1
interface -- refer to ''DTMF & Dialing Parameters'' on page 123)
•
DTMFTransportType = 2 (DTMF Transport Type = Transparent DTMF)
Using INFO message according to Korea mode: DTMF digits are carried to the
remote side in INFO messages. To enable this mode, define the following:
•
RxDTMFOption = 0 (ini file); 'Declare RFC 2833 in SDP' field = 'No' (Web
interface -- refer to ''DTMF & Dialing Parameters'' on page 123)
•
TxDTMFOption = 3 (ini file); '1
(Web interface -- refer to ''DTMF & Dialing Parameters'' on page 123)
Note that in this mode, DTMF digits are erased from the audio stream
(DTMFTransportType is automatically set to 0 (DTMF Mute)).
Notes:
The following parameters affect the way the device handles the DTMF digits:
TxDTMFOption, RxDTMFOption, and RFC2833PayloadType (described in ''DTMF &
Dialing Parameters'' on page 123)
MGCPDTMFDetectionPoint, DTMFVolume, DTMFTransportType, DTMFDigitLength,
and DTMFInterDigitInterval (refer to ''Channel Parameters'' on page 297)
7.2

Fax and Modem Capabilities

7.2.1

Fax/Modem Operating Modes

The device supports two modes of operations:
Fax / modem negotiation that isn't performed during the establishment of the call.
VBD mode for V.152 implementation (refer to ''Supporting V.152 Implementation'' on
page 321): fax / modem capabilities are negotiated between the device and the
SIP User's Manual
•
The device is always ready to receive DTMF packets over IP in all
possible transport modes: INFO messages, NOTIFY, and RFC 2833 (in
proper payload type) or as part of the audio stream.
•
To exclude RFC 2833 Telephony event parameter from the device's
SDP, set RxDTMFOption to 0 in the ini file.
to 5 Tx DTMF Option' field = 'Disable' (Web
st th
to 5 Tx DTMF Option' field = 'INFO (Korea)'
st th
314
MediaPack Series
Document #: LTRT-65410