Subject: Connection migration PR

From: Jana Iyengar <[email-masked]>
Date: Sun, 11 Feb 2018 22:59:01 -0800

FYI: PR #1012 <https://github.com/quicwg/base-drafts/pull/1012> about
connection migration.

This PR replaces the existing connection migration mechanism in the draft
with one that allows a client to probe from an alternate address before
actually migrating to it. It also fixes a few holes in the current
mechanism.

I've done a rewrite based on the comments on the previous version and from
the interim. The packet number skip behavior remains unchanged, but that's
going to have to come out of the ongoing packet number encryption
conversation. For the time being, I would like to leave that aspect
untouched in this PR.

FWIW, encrypting packet numbers makes it trivial to not track state across
multiple connection IDs in series. It needs careful thought otherwise.

I am also limiting the migration protocol to client migration since making
the description symmetric adds sharp edges that need to be more carefully
dealt with. I'm restricting the scope of this PR to the client/server use
case that's most relevant for v1.