Nortel Networks Mediant TP-1610 SIP - Manual (Page 144)

Mediant 2000 SIP
Mediant 2000 SIP User’s Manual 144 Document #: LTRT-72504
5. Sending DTMF digits (in RTP packets) as part of the audio stream (DTMF Relay is disabled):
Note that this method is normally used with G.711 coders; with other Low Bit Rate (LBR)
coders the quality of the DTMF digits is reduced.
To set this mode:
‘IsDTMFUsed = 0’ (Use Out-of-Band DTMF = No)
‘TxDTMFOption = 0’ (DTMF RFC 2833 Negotiation = Disable)
‘RxDTMFOption = 0’ (Declare RFC 2833 in SDP = No)
‘DTMFTransportType = 2’ (DTMF Transport Type = Transparent DTMF)
Note 1: 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.
Note 2: 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 Mediant 2000 SIP handles the DTMF digits:
Table 8-3: Summary of DTMF Configuration Parameters (continues on pages 144 to 145)
ini File Field Name
[Web Name]
Valid Range and Description
IsDTMFUsed
[
Use Out-of-Band DTMF ]
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).
OutOfBandDTMFFormat
[Out-of-Band DTMF Format] The exact method to send out-of-band DTMF digits
1 = INFO format (Nortel)
2 = INFO format (Cisco) - (default)
3 = NOTIFY format
Note 1:
To use out-of-band DTMF, set “IsDTMFUsed=1”.
Note 2: When using out-of-band DTMF, the “DTMFTransportType” parameter is
automatically set to 0, to erase the DTMF digits from RTP path.
TxDTMFOption
[DTMF RFC 2833
Negotiation] 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.