[Asterisk-Dev] codecrenegotiation andfax [was:codec negotiationissue]

[Jesse Kaijen]

> .......
> My experience to date has been only with SIP, where renegotiation of
> codecs is already supported. I spoke with Steve Kann briefly on IRC a
> few weeks ago and he seemed to think that doing renegotiation in IAX2
> would be easy to add.
> 
I think that's true. Currently I've added one command to IAX2 to start the
renegotiation. Now my clients can renegotiate a new codec during a call.
When I read your post that renegotiation already was possible in IAX2 I was
a little anxious to know how to do that. 

> ......
> My work has been focused on making Asterisk internals remember what
> codecs the peers can support, and initiating renegotiation when needed
> as channels are bridged. Initially my efforts will be focused on making
> chan_sip react to these requests and renegotiate with its peer(s), but
> any help available in extending this to IAX2 would be welcome.
> 
> As far as renegotiation initiated from the IAX2 peer end (not Asterisk),
> that will require someone who knows IAX2 better than I do to determine
> what will be needed to indicate that negotiation is wanted.

My research is to determine when to start negotiation during a call. So the
end user has a better audio perceptive. 
One of the options I'm looking in as well is the possibility to send each
audio frame twice. I know it's nasty but some people believe it will help
against leeching programs like kazaa. Maybe an idea to implement a command
for this. But PLEASE don't start a useless discussion on it will work, it
won't work. I will research this.

When there's a discussion on the IAX2 protocol, please keep me informed.
Possible I can help as well on this.