On Thu, Dec 1, 2016 at 8:00 PM, Mark Nottingham <mnot@mnot.net> wrote:
>
> That's another way to do it too, provided the latency hit isn't critical.
> Since you've already got the H2 connection open in the typical case for WS,
> I think that'd work well, but I could be unaware of some use case that
> requires WS on the first RT.
Doing it with settings on alpn=h2 is a little tricky.. if you need to make
a new connection (e.g. you have none open) for wss do you do it with
alpn=h2 and hope for the setting and then fall back to a new connection
with h1 and upgrade if it doesn't work? That's a new pile of round trips
for legacy servers. otoh doing it via alpn makes it easy by offering
wsoverh2 and h1 in the handshake.. it also makes it easy for the h1 server
to use alt-svc to advertise a better version elsewhere as we see quic do.