- From: Kari Hurtta <hurtta-ietf@elmme-mailer.org>
- Date: Sat, 11 Nov 2017 21:30:19 +0200 (EET)
- To: Amos Jeffries <squid3@treenet.co.nz>
- CC: Kari Hurtta <hurtta-ietf@elmme-mailer.org>, HTTP Working Group <ietf-http-wg@w3.org>, HYBI Working Group <hybi@ietf.org>, Patrick McManus <pmcmanus@mozilla.com>
Amos Jeffries <squid3@treenet.co.nz>: (Sat Nov 11 16:17:01 2017) > If ":upgrade" has the same optional nature as Upgrade did there is zero > point in creating it. Just use the existing Upgrade header in the > HEADERS frame. That does not require any negotiation. > > > The whole point of SETTINGS is to promise the recipient of that frame > that the things mentioned in it will work. No maybes or guessing. > > This guarantee provided by SETTINGS is one of the ways HTTP/2 improves > over HTTP/1.1. No more sending maybe-ignored headers and hoping for > success a few RTT later. The client can know up front whether that > connection is a usable channel for the negotiable feature or not. > Sidenote: If you want SETTINGS to tell that websocket can be used over HTTP/2 then :upgrade = and SETTINGS ENABLE_UPGRADE is no go. No general tunneling as Kazuho Oku <kazuhooku@gmail.com> as suggesting in that thread: https://lists.w3.org/Archives/Public/ietf-http-wg/2017OctDec/0209.html > If we adjust the three issues (for example, by allowing any method to > be specified, and use the existence of :upgrade: pseudo header as a > signal; use 101 to signal protocol change; use attributes of :upgrade: > header to specify additional headers required for the upgrade), I > think the approach would become generic. > > For example, creating a websocket tunnel through HTTP/2 would look like below. In that case SETTINGS ENABLE_UPGRADE tells nothing what upgrades are available (or you need to do registry for different 32-bit values of ENABLE_UPGRADE to map possible upgrade protocols). Same to say about SETTINGS ENABLE_CONNECT_PROTOCOL and :protocol = You are asking SETTINGS ENABLE_WEBSOCKET then and that is not proposed on draft-mcmanus-httpbis-h2-websockets-01 either. / Kari Hurtta
Received on Saturday, 11 November 2017 19:31:10 UTC