AASTRA SIP-DECT (Release 1.8)-Installation- and Administration Guide EN - Manual (Page 40)

Installation, Administration and Maintenance
Aastra depl-0900/0.4 Page: 40 (104)
not.
.
• DTMF Method
The OMM supports the following DTMF Out-of-Band methods:
o RFC 2833
Transmit DTMF as RTP events according to RFC 2833
(/9/) after the payload type negotiation via SIP/SDP. If the
payload type is not negotiated, “inband” will be used
automatically.
o INFO
The SIP INFO method is used to transmit DTMF tones as
telephone events (application/dftmf-relay). This setting
should be used if RFC 2833 is not supported.
o BOTH
DTMF telephones events are send according to RFC
2833 and as well as SIP INFO method.
Please Note: Possibly, the other party recognises events
twice.
DTMF Payload Type
If Out-of-Band is enabled the Payload Type specify the payload type which is used for
sending DTMF events based on Section 1.3 reference /9/.