Nortel Networks TP-1610 SIP user manual Configuring the Dtmf Transport Types

Mediant 2000 SIP User’s Manual 8. Gateway Capabilities Description

8.5Configuring the DTMF Transport Types

You can control the way DTMF digits are transported over the IP network to the remote endpoint. The following five modes are supported:

1.Using INFO message according to the Nortel IETF draft:

In this mode DTMF digits are carried to the remote side within INFO messages. To enable this mode set:

‘IsDTMFUsed = 1’	(Protocol Management>Protocol Defenition>DTMF
& Dialing>Use Out-of-Band DTMF = Yes)
‘OutOfBandDTMFFormat = 1’	(Protocol Management>Protocol Defenition>DTMF
& Dialing>Out-of-Band DTMF Format = INFO (Nortel))
‘RxDTMFOption = 0’	(Protocol Management>Protocol Defenition>DTMF

& Dialing>Declare RFC 2833 in SDP = No)

Note that in this mode DTMF digits are erased from the audio stream (DTMFTransportType is automatically set to 0).

2.Using INFO message according to Cisco’s style:

In this mode DTMF digits are carried to the remote side within INFO messages. To enable this mode set:

‘IsDTMFUsed = 1’	(Use Out-of-Band DTMF = Yes)
‘OutOfBandDTMFFormat = 2’	(Out-of-Band DTMF Format = INFO (Cisco))
‘RxDTMFOption = 0’	(Declare RFC 2833 in SDP = No)

Note that in this mode DTMF digits are erased from the audio stream (DTMFTransportType is automatically set to 0).

3.Using NOTIFY messages according to <draft-mahy-sipping-signaled-digits-01.txt>: In this mode DTMF digits are carried to the remote side using NOTIFY messages. To enable this mode set:

‘IsDTMFUsed = 1’	(Use Out-of-Band DTMF = Yes)
‘OutOfBandDTMFFormat = 3’	(Out-of-Band DTMF Format = NOTIFY)
‘RxDTMFOption = 0’	(Declare RFC 2833 in SDP = No)

Note that in this mode DTMF digits are erased from the audio stream (DTMFTransportType is automatically set to 0).

4.Using RFC 2833 relay with Payload type negotiation:

In this mode, DTMF digits are carried to the remote side as part of the RTP stream in accordance with RFC 2833 standard.

To enable this mode set:

‘IsDTMFUsed = 0’ (Use Out-of-Band DTMF = No)

‘TxDTMFOption = 4’ (Protocol Management>Protocol Defenition>DTMF & Dialing> DTMF RFC 2833 Negotiation = Enable)

‘RxDTMFOption = 3’ (Declare RFC 2833 in SDP = Yes)

‘DTMFTransportType = 3’ (Advanced Configuration>Channel Settings>Voice Settings>DTMF Transport Type = RFC 2833 Relay DTMF)

Note that to set the RFC 2833 payload type with a different value (other than its default, 96) configure the ‘RFC2833PayloadType’ parameter. The gateway negotiates the RFC 2833 payload type using local and remote SDP and sends packets using the PT from the received SDP. The gateway expects to receive RFC 2833 packets with the same PT as configured by the ‘RFC2833PayloadType’ parameter. The RFC 2833 packets are sent even if the remote side didn't include the send "telephone-event" parameter in its SDP, in which case the gateway uses the same PT for send and for receive.

Version 4.4 143 July 2005