Re: [MMUSIC] UPDATE mechanism for Trickle ICE - Comment on draft-ivov-mmusic-trickle-ice-sip-01

[Emil Ivov <[e-mail]>]

On Thu, Oct 24, 2013 at 5:36 PM, Jonathan Lennox <[e-mail]> wrote:
>
> On Oct 24, 2013, at 10:34 AM, Christer Holmberg <[e-mail]>
>  wrote:
>
>> Hi,
>>
>>>> We have to remember, though, that a trickled candidate is not a new
>>>> candidate "type". The candidate types you trickle are the same types
>>>> you send in Offer/Answer - tickle is simply an alternative candidate
>>>> transport mechanism.
>>>
>>> Yes, that's right. I am not sure why you are saying it though.
>>
>> Because when you say:
>>
>>       "we treat trickle candidates in the same way as peer-reflexive candidates"
>>
>> ...it sounds like a trickle candidate is a new type of candidate (similar to peer-reflexive candidate), which is not true.
>>
>>
>> You should say:
>>
>>       "We treat candidates that were provided using the trickle ICE mechanism in the same way as peer-reflexive candidates"
>
> There's a problem with this.
>
> RFC 5245 says:
>
>    However, the peer reflexive candidate is not paired with other remote
>    candidates.  This is not necessary; a valid pair will be generated
>    from it momentarily based on the procedures in Section 7.1.3.2.2.  If
>    an agent wishes to pair the peer reflexive candidate with other
>    remote candidates besides the one in the valid pair that will be
>    generated, the agent MAY generate an updated offer which includes the
>    peer reflexive candidate.
>
> In other words, peer-reflexive candidates aren't automatically paired with all remote candidates; they're only paired with the remote candidate you were checking when you discovered them, unless you send them in an updated offer.
>
> Candidates provided over Trickle don't have a remote candidate to be automatically paired with, so "treating them like peer-reflexive candidates" doesn't make much sense.

No it doesn't. The idea is that "trickled candidates" being exchanged,
checked and selected entirely outside the context of Offer/Answer is
not a problem because we already have this with "peer-reflexive
candidates".

Trickled candidates obviously do need specific handling within the
*ice agents*, which is one of the reasons for the existence of the
trickle ICE drafts.

Cheers,
Emil

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