Polycom: polycom_dtmf_settings

==== Current settings - not good for Sip Trunking ====

* viaRtp = OFF
* rfc2833Control = OFF
* chassis.masking = ON

tone.dtmf.level="-15"
tone.dtmf.onTime="50"
tone.dtmf.offTime="50"
tone.dtmf.chassis.masking="1"
tone.dtmf.stim.pac.offHookOnly="0"
tone.dtmf.viaRtp="0"
tone.dtmf.rfc2833Control="0"
tone.dtmf.rfc2833Payload="101"/>

=== Polycom manual ===

== tone.dtmf.chassis.masking 0, 1 Default: 0 ==

If set to 1, DTMF tones will be substituted with a non-DTMF pacifier tone when dialing in hands-free mode.\\
This prevents DTMF digits being broadcast to other surrounding telephony devices or being inadvertently transmitted in-band due to local acoustic echo.

Note: tone.dtmf.chassis.masking should only be enabled when tone.dtmf.viaRtp is disabled.

This is because when tones are being used, the pacifier tone setting makes the tones not work.


== tone.dtmf.viaRtp 0, 1 Default: 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 Default: 1 ==

If set to 1, the telephone will indicate a preference for encoding DTMF via RFC 2833 format in its Session Description Protocol (SDP) offers by showing support for the telephone-event payload type;\\
this does not affect SDP answers, these will always honor the DTMF format present in the offer since the telephone has native support for RFC 2833

=== Previous tests - conclusions questionable ===


== viaRtp = OFF rfc2833Control = OFF chassis.masking = OFF SDP-has-rfc2833 = ??? ==

Audio DTMF - current setting.

== viaRtp = ON rfc2833Control = OFF chassis.masking = OFF SDP-has-rfc2833 = NO ==

Audio DTMF - equivalent to current setting with current SDP. <-- this was not right

== viaRtp = ON rfc2833Control = OFF chassis.masking = OFF SDP-has-rfc2833 = YES ==

RFC 2833 DTMF - this allows rfc2833 to be turned on by the server call by call.

== viaRtp = ON rfc2833Control = OFF chassis.masking = ON SDP-has-rfc2833 = NO ==

If both chassis.masking and viaRtp are enabled,
the Polycom will send the worthless pacifier tone instead of DTMF to the far end.

== viaRtp = ??? rfc2833Control = ON chassis.masking = OFF SDP-has-rfc2833 = ??? ==

RFC 2833 DTMF is forced - this was what was causing the problems.

==== Current settings Alteva SIP Trunking ====

# grep dtmf ipmid.cfg

tone.dtmf.level="-15"
tone.dtmf.onTime="50"
tone.dtmf.offTime="50"
tone.dtmf.chassis.masking="0"
tone.dtmf.stim.pac.offHookOnly="0"
tone.dtmf.viaRtp="1"
tone.dtmf.rfc2833Control="1"

==== New settings - Good for Sip Trunking ====

* viaRtp = ON
* rfc2833Control = ON
* chassis.masking = OFF

* tone.dtmf.viaRtp="1"
* tone.dtmf.rfc2833Control="1"
* tone.dtmf.chassis.masking="0"