While debugging a SIP trunk with an Avaya IPO, I noticed that wiki’s PJSIP
dtmf_mode at  includes:
“This setting allows to choose the DTMF mode for endpoint communication.
rfc4733 – DTMF is sent out of band of the main audio stream. This supercedes the older RFC-2833 used within the older chan_sip.
inband – DTMF is sent as part of audio stream.
info – DTMF is sent as SIP INFO packets.
auto – DTMF is sent as RFC 4733 if the other side supports it or as INBAND if not.
auto_info – DTMF is sent as RFC 4733 if the other side supports it or as SIP INFO if not.”
The above description doesn’t mention anything about incoming DTMF
treatment. May I suggest that:
– either dtmf_mode has no influence itself on incoming DTMF treatment and it could be explicitely mentioned,
– either dtmf_mode has an influence itself on incoming DTMF treatment and this could be described.
What do you think of this ?