Re: Advertising WebSocket support in the HTTPS resource record

On Wed, Oct 20, 2021 at 12:27 PM Lucas Pardue <>

> On Wed, 20 Oct 2021, 17:11 Ben Schwartz, <> wrote:
>> Rather than optimize the performance of origins that use WebSockets, and
>> support HTTP/2 and HTTP/3, but only support WebSockets on HTTP/1.1, I would
>> prefer to encourage server deployment of WebSockets support on all HTTP
>> versions.  We could also consider documenting a parallel connection
>> strategy for clients, if it's important to avoid a fallback delay.
> That's an interesting point. Extended CONNECT isn't just for Websockets,
> as we are seeing with MASQUE developments. So I would expect cases where a
> server only :protocol connect-udp and NOT websockets, or vice versa. So to
> make this type of thing work, it seems like what is needed is a protocol
> hint (singular or a list) too.

My expectation is that the supported :protocols are handled like the
supported paths: the client knows which one it needs from the URI (e.g.
wss://..., https://.../foo), and the origin had better support it if it is
advertising those URIs anywhere.  I don't think we need a pre-connection
hint about the supported :protocols.

Received on Wednesday, 20 October 2021 16:35:46 UTC