Re: [MMUSIC] Merging ICE aggressive and regular nomination (was Re: [tram] Comment on draft-williams-peer-redirect-01: might it not converge?)

Martin Thomson <martin.thomson@gmail.com> Wed, 30 July 2014 22:57 UTC

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Date: Wed, 30 Jul 2014 15:57:42 -0700
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From: Martin Thomson <martin.thomson@gmail.com>
To: Jonathan Lennox <jonathan@vidyo.com>
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Subject: Re: [MMUSIC] Merging ICE aggressive and regular nomination (was Re: [tram] Comment on draft-williams-peer-redirect-01: might it not converge?)
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On 30 July 2014 15:51, Jonathan Lennox <jonathan@vidyo.com> wrote:
>
> On Jul 30, 2014, at 6:28 PM, Martin Thomson <martin.thomson@gmail.com> wrote:
>> If the controlled peer really does use this as a signal that it's safe
>> to close out other candidates, then you really do have to have just
>> the one instance.  Is attaching that semantic safe?  I assume that we
>> would have to signal in both directions that this new meaning is
>> acceptable first.  (a=ice-options again)
>
> 5245 8.3.1:
>    Once ICE processing
>    has reached the Completed state for all peers for media streams using
>    those candidates, the agent SHOULD wait an additional three seconds,
>    and then it MAY cease responding to checks or generating triggered
>    checks on that candidate.  It MAY free the candidate at that time.
> You enter the “Completed” state once all components of all streams have sent or received (as appropriate) USE-CANDIDATE.
>
> The “all peers” clause is needed for SIP, to handle forking cases.  For non-forking uses of ICE, “all peers” is equivalent to “the peer”.


I was looking for a stronger signal.  This assumes that the active
pair is the one with the highest candidate for which USE-CANDIDATE has
been sent or received.  But we've been talking about making other
choices.  That would avoid the need for a 3s cleanup timer.