[asterisk-dev] Regarding the "progressinband" SIP option

[Pavel Troller]

Hi!
  First of all, Happy New Year to all of you, and a really big success of
Asterisk!

  And now, to the business. I'm a bit misoriented with the "progressinband"
option in chan_sip. When it is sent to "never", Asterisk doesn't generate
ringing tone, but sends "180 Ringing" provisional response. The other
options (no, yes) behaved identically on my setup, causing Asterisk to send
a ringing tone but not 180 Ringing.
  What I would like, is to send both of them. For example, on the Linksys
phones, without "180 Ringing" being sent, display shows "Session progress"
for all the time until the answer. It's much nicer to see "Ringing". These
phones also have a "Sticky 183" config option, which allows to keep the
media stream established by 183 Session Progress open, even when 180 Ringing
comes back, so I can hear the real media from the switch, not local ringing
tone of the phone. 
  The only way to achieve this for me (in 1.6.1.12) was to patch the source
to return -1 from sip_indicate() even after sending 180 Ringing. It then 
behaves as I want (if I set progressinband=never, which of course is now
totally  misleading :-). Isn't there some way, how to do it "legally" :-) ?
If not, I'm voting for adding it, for example by adding the fourth value
"both" to the progressinband option, which would make this possible.
  Are there any objections against it ? If not, I'm willing to prepare
a small patch.


With regards, Pavel.