Re: Restarting ICE

On Wed, Apr 3, 2013 at 11:09 PM, Adam Bergkvist <adam.bergkvist@ericsson.com
> wrote:

> On 2013-04-04 07:13, Harald Alvestrand wrote:
>
>> On 04/04/2013 01:23 AM, Justin Uberti wrote:
>>
>>> Nitpick: I propose it be called "IceRestart", for consistency with the
>>> existing "IceTransports".
>>>
>>
>> Works for me. It's also consistent with the pattern that constraints are
>> nouns, not verbs.
>>
>
> I think this is pretty uncontroversial, since it was a while since we
> decided to do ice restart via "new credentials"/**setLocalDescription(),
> and the spec incomplete on this matter at the moment.
>
> Detail to pin down: is this constraint valid for both createOffer() and
> createAnswer()?
>

I don't think it needs to be (or should be) specified to createAnswer. If
you receive an offer with changed ICE credentials, you MUST generate
changed ICE credentials in the answer (
http://tools.ietf.org/html/rfc5245#section-9.2.1.1).

>
> Thought: ICE restart is obviously a consequence of setting a description
> with new ICE credentials, but is that the only reason why you would have
> new credentials? I mean, should the constraint actually be called something
> like "GenerateNewIceCredentials" and ICE restart is only a consequence of
> setting the new description?


Yes. Also from 9.2.1.1:

   If the offer contained a change in the a=ice-ufrag or a=ice-pwd
   attributes compared to the previous SDP from the peer, it indicates
   that ICE is restarting for this media stream.