[Nice] Gracefull fallback, renegotiations?

[Kai.Vehmanen at nokia.com]

Hi,

On 05 May 2008, Mikhail Zabaluev wrote:
>I'm interested in developing a SIP client implementation that 
>would use libnice.
>I have a few issues to resolve with the current libnice API in 
>the way it can be exposed through Farsight 2.
[...]
>1. Let's suppose peer A makes an ICE-enhanced SDP offer to 
>peer B. The latter, however, processes the offer as plain SDP 
>and returns an answer that doesn't have any ICE attributes. 
>The client at peer A is supposed to tell libnice to stop any 
>ICE processing and fall back to sending plain RTP/RTCP 
>payloads over the network sockets initially opened for ICE.

this is covered by the library design, see nice/docs/design.txt
and "Handling fallback to non-ICE operation". OTOH, I'm not sure
if this is covered in Farsight 2 API.

>2. We have successfully negotiated a candidate pair, then an 
>updated SDP offer (variant: an answer from another dialog 
>that's won in forking) comes in, which necessitates a 
>renegotiation. 

Then you should do an ICE restart (see "Restarting ICE" in
design.txt).

-- 
first.surname at nokia.com (Kai Vehmanen)