3Com VCX V7122 User Manual page 148

'RxDTMFOption = 0'
'DTMFTransportType = 2'
The gateway 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 gateway's SDP, set
'RxDTMFOption = 0' in the ini file.
The following parameters affect the way the VCX V7122 SIP handles the DTMF digits:
Table 34 Summary of DTMF Configuration Parameters
ini File Field Name
[Web Name]
IsDTMFUsed
[Use Out-of-Band DTMF]
OutOfBandDTMFFormat
[Out-of-Band DTMF
Format]
TxDTMFOption
[DTMF RFC 2833
Negotiation]
148
Valid Range and Description
Use out-of-band signaling to relay DTMF digits.
0 = Disable, DTMF digits are sent according to DTMFTransportType parameter (default).
1 = Enable sending DTMF digits within INFO or NOTIFY messages.
Note: When out-of-band DTMF transfer is used, DTMFTransportType is automatically set
to 0 (erase the DTMF digits from the RTP stream).
The exact method to send out-of-band DTMF digits.
1 = INFO format (Nortel).
2 = INFO format (Cisco) - (default).
3 = NOTIFY format <draft-mahy-sipping-signaled-digits-01.txt>.
Note 1: To use out-of-band DTMF, set "IsDTMFUsed=1" or "Enable DTMF = yes".
Note 2: When using out-of-band DTMF, the "DTMFTransportType" parameter is
automatically set to 0, to erase the DTMF digits from RTP path.
0 = No negotiation, DTMF digit is sent according to the parameters 'DTMFTransportType'
and 'RFC2833PayloadType'.
4 = Enable RFC 2833 payload type (PT) negotiation.
Note 1: This parameter is applicable only if "IsDTMFUsed=0" (out of-band DTMF is not
used).
Note 2: If enabled, the gateway:
Negotiates RFC 2833 payload type using local and remote SDPs.
Sends DTMF packets using RFC 2833 PT according to the PT in the received SDP.
Expects to receive RFC 2833 packets with the same PT as configured by the
"RFC2833PayloadType" parameter.
Note 3: If the remote party doesn't include the RFC 2833 DTMF relay payload type in the
SDP, the gateway uses the same PT for send and for receive.
Note 4: If TxDTMFOption is set to 0, the RFC 2833 payload type is set according to the
parameter 'RFC2833PayloadType' for both transmit and receive.
3Com VCX V7122 SIP VoIP Gateway User Manual