Re: [quicwg/base-drafts] Word-smithed version of Ted's resolution to #3842 from the mailing list (#3945)

[Mike Bishop <[e-mail]>]

@MikeBishop commented on this pull request.



>  immediately reset the congestion controller and round-trip time estimator for
 the new path to initial values (see Appendices A.3 and B.3 in {{QUIC-RECOVERY}})
-unless it has knowledge that a previous send rate or round-trip time estimate is
-valid for the new path.  For instance, an endpoint might infer that a change in
-only the client's port number is indicative of a NAT rebinding, meaning that the
-new path is likely to have similar bandwidth and round-trip time. However, this
-determination will be imperfect.  If the determination is incorrect, the
-congestion controller and the RTT estimator are expected to adapt to the new
-path.  Generally, implementations are advised to be cautious when using previous
-values on a new path.
+unless the only change is the other endpoint's port number.  Because

Correctly predicting a NAT rebind isn't an "attempt" to switch paths.  It's using the same path, but making a guess about what might have happened.

If you're not going to reset the congestion controller when the port changes without the peer realizing it, and you're not going to reset the congestion controller if the peer guesses they're about to get rebound but doesn't, then I don't think it makes sense to reset it if they guess and are right.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/quicwg/base-drafts/pull/3945#discussion_r470207946