Polycom SOUNDPOINT SIP 3.1 - Manual (Page 183)

Configuration Files
A - 29
Chord-Sets <chord/>
Chord-sets are the building blocks of sound effects that use synthesized rather
than sampled audio (most call progress and ringer sound effects). A chord-set
is a multi-frequency note with an optional on/off cadence. A chord-set can
contain up to four frequency components generated simultaneously, each
with its own level.
There are three blocks of chord sets:
• callProg (used for call progress sound effect patterns)
• ringer
• misc (miscellaneous)
All three blocks use the same chord set specification format.
tone.dtmf.viaRtp 0, 1 1 If set to 1, encode DTMF in the active
RTP stream, otherwise, DTMF may be
encoded within the signaling protocol only
when the protocol offers the option.
Note: tone.dtmf.chassis.masking should
be enabled when tone.dtmf.viaRtp is
disabled.
tone.dtmf.rfc2833Control 0, 1 1 If set to 1, the phone will indicate a
preference for encoding DTMF through
RFC 2833 format in its Session
Description Protocol (SDP) offers by
showing support for the phone-event
payload type; this does not affect SDP
answers, these will always honor the
DTMF format present in the offer since
the phone has native support for RFC
2833.
tone.dtmf.rfc2833Payload 96-127 101 The phone-event payload encoding in the
dynamic range to be used in SDP offers.
Attribute
Permitted
Values
Default Interpretation