Re: New Version Notification for draft-momoka-httpbis-settings-enable-websockets-00.txt

[Ben Schwartz <[e-mail]>]

On Thu, Jan 19, 2023 at 8:47 AM Momoka Yamamoto <[e-mail]>
wrote:

> Hello,
> Thank you both for your response.
>
> Most clients have solved this problem by not implementing RFC 8441 at
>> all.  Chromium has implemented it, with an interesting workaround: Extended
>> CONNECT is only used if a suitable socket with
>> SETTINGS_ENABLE_CONNECT_PROTOCOL is already available.  If a fresh
>> connection is needed for wss://, Chromium always uses HTTP/1.1. (See
>> https://docs.google.com/document/d/1ZxaHz4j2BDMa1aI5CQHMjtFI3UxGT459pjYv4To9rFY/edit#
>> .)
>>
>
> This is the use case I am thinking of but for WebSockets over HTTP/3.
> Chromium uses WebSockets over HTTP/2 if there is an existing HTTP/2
> connection that has received SETTINGS_ENABLE_CONNECT_PROTOCOL.
> However, it cannot do the same for HTTP/3 because receiving
> SETTINGS_ENABLE_CONNECT_PROTOCOL currently does not guarantee support for
> WebSockets over HTTP/3. SETTINGS_ENABLE_CONNECT_PROTOCOL will be sent for
> other protocols as well.
>

Thanks for helping me to understand the motivation for this proposal.  Do
you believe there are existing origins that
1. Offer SETTINGS_ENABLE_CONNECT_PROTOCOL in HTTP/3 AND
2. Operate WebSocket services AND
3. Don't support WebSocket over HTTP/3 AND
4. Are not willing to implement WebSocket over HTTP/3
?

If so, then I agree we have a problem.  If not, I think the best course of
action is to assume that the origin's supported "Upgrade Tokens"/":protocol
values" are independent of HTTP version, except where the IETF has ruled
out support for a particular combination of :protocol and HTTP version.

It would be nice if a client could know if the existing HTTP/3 connection
> supports bootstrapping WebSockets.
>

In my view, clients are free to assume this when they see a wss:// link to
an origin that offers SETTINGS_ENABLE_CONNECT_PROTOCOL in HTTP/3.

...

> It would be nice if a client could know if the server supports
> Bootstrapping WebSockets over HTTP/2 or HTTP/3 before initiating a
> connection to the server.
>

Interesting!  Publishing a flag for SETTINGS_ENABLE_CONNECT_PROTOCOL in the
HTTPS record seems plausible to me.

...