Re: [Ice] I submitted and plan to present draft-thatcher-ice-remove-candidate in Berlin

"Removal" and "Renomination" have both come up as implementation issues, so
these drafts seem useful to me.

In the "removal" draft, I had questions about these paragraphs:

   When a removal signal [is received], the Receiving Agent MUST NOT
pair the Removed
   Candi[d]ates with any future candidates gathered by the Receiving Agent.
   The Receiving Agent MAY keep the existing candidate pairs that use
   the Removed Candidates and behave as though the Removed Candidates
   had not been removed for those candidate pairs.

   Why would an Receiving Agent choose not to immediately remove
   existing candidate pairs?  Because the Removing Agent MAY choose to
   keep the Removed Candidate capable of receiving ICE checks and
   sending responses so that any ICE checks already sent by the
   Receiving Agent may continue to work briefly so that media can flow
   as quickly as possible, even if over a candidate pair that will soon
   be discarded.

[BA] When an interface is "going down", having the Receiving Agent not
immediately remove existing candidate pairs can avoid a media glitch.

However there are consequences to not removing the pair immediately
because when the interface goes down, consent checks will subsequently
fail and RFC 7675 Section 5.1 indicates that the pair cannot be used
with the same ICE credentials, even if the interface comes up again:

   After consent is lost, the same ICE credentials MUST NOT be used on
   the affected 5-tuple again.  That means that a new session, or an ICE
   restart, is needed to obtain consent to send on the affected
   candidate pair.

One way to deal with this would be for the removing party to revoke
consent before bringing the interface down.  However, that would only
work if consent revocation was not considered the same as "consent is
lost" in the above paragraph from RFC 7675.

On Tue, Jul 12, 2016 at 7:35 AM, Peter Thatcher <pthatcher@google.com>
wrote:

> I submitted draft-thatcher-ice-remove-candidate and would like to speak
> about in my allotted time on the agenda when I will also be speaking about draft-thatcher-ice-network-cost
> and draft-thatcher-ice-renomination.
>
> It's a very simple draft. Basically it says you can "remove" candidates
> just like trickle-ice allows you to add candidates. You could probably
> read it in 3 minutes. Please do so:
>
> https://www.ietf.org/id/draft-thatcher-ice-remove-candidate-00.txt
>
> Thanks,
> Peter (Chair hat off)
>
> _______________________________________________
> Ice mailing list
> Ice@ietf.org
> https://www.ietf.org/mailman/listinfo/ice
>
>