3Com VCX v7111 User Manual page 87

Parameter
Declare RFC 2833 in SDP
[RxDTMFOption]
st th
1 to 5 Tx DTMF Option
[TxDTMFOption]
RFC 2833 Payload Type
[RFC2833PayloadType]
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3Com VCX V7111 VoIP Gateway User Guide
Description
Defines the supported Receive DTMF negotiation method.
No [0] = Do notdeclare RFC 2833 telephony-event parameter in SDP
Yes [3] = Declare RFC 2833 telephony-event parameter in SDP (default)
The V7111 is designed to always be receptive to RFC 2833 DTMF relay
packets. Therefore, it is always correct to include the telephony-event
parameter as a default in the SDP. However some gateways use the absence
of the telephony-event from the SDP to decide to send DTMF digits in-band
using G.711 coder, if this is the case you can set RxDTMFOption=0.
Determines a single or several preferred transmit DTMF negotiation methods.
0 (Not Supported) = No negotiation, DTMF digits are sent according to the
parameters 'DTMFTransportType' and 'RFC2833PayloadType' (default).
2 (NOTIFY) = Sends DTMF digits according to <draft-mahy-sipping-signaled-
digits-01>.
4 (RFC 2833).
DTMF negotiation methods are prioritized according to the order of
their appearance.
When out-of-band DTMF transfer is used (3, 5 or 6), the parameter
DTMFTransportType is automatically set to 0 (DTMF digits are erased
from the RTP stream).
When RFC 2833 (4) is selected, the gateway:
Negotiates RFC 2833 Payload Type (PT) 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 parameter RFC2833PayloadType.
Uses the same PT for send and receive if the remote party does
not include the RFC 2833 DTMF PT in its SDP.
When TxDTMFOption is set to 0, the RFC 2833 PT is set according to
the parameter RFC2833PayloadType for both transmit and receive.
ini file note: The DTMF transmit methods are defined using a
repetition of the same (TxDTMFOption) parameter (up to five options
can be provided).
The RFC 2833 DTMF relay dynamic payload type.
Range: 96 to 99, 106 to 127; Default = 96
The 100, 102 to 105 range is allocated for proprietary usage.
When RFC 2833 payload type (PT) negotiation is used
(TxDTMFOption=4), this payload type is used for the received DTMF
packets. If negotiation is not used, this payload type is used for
receive and for transmit.
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