Re: [Moq] Exploring HTTP/3

[Lucas Pardue <[e-mail]>]

Hey Spencer,

On Thu, 9 Feb 2023, 16:00 Spencer Dawkins at IETF, <
[e-mail]> wrote:

> Lucas,
>
> On Wed, Feb 8, 2023 at 4:55 PM Lucas Pardue <[e-mail]>
> wrote:
>
>>
>>> And yeah, I agree that browsers are the main obstacles when pushing
>>> media, but that doesn't change too much with WebTransport. We still need a
>>> way to set the priority when pushing a WebTransport stream, much like we
>>> would need a way to set the priority when issuing a HTTP PUT. I suppose
>>> it's easier to modify WebTransport since it's in development.
>>>
>>
>> The W3C WebTransport WG has been considering the questions of
>> prioritization and congestion control feedback for a relatively long time.
>> And we have been making progress. It has the right people and the right
>> charter to work on it. I'm a little pessimistic about trying to get
>> momentum for HTTP upload changes MoQ could require, in the sorts of
>> timeframes that MoQ would find useful. For context, fetch *does *even
>> support preference of HTTP version, nor exposese connection pooling. But
>> maybe I'm too conservative in this regard. Asking ourselves the questions
>> is definitely worthwhile.
>>
>
> Could this have been "fetch *does NOT* even support preference of HTTP
> version"?
>
> I was guessing so, but didn't want to guess when I could ask.
>

Yes you're right. Thanks for spotting that! I always appreciate a careful
eye.

At the HTTP semantic layer, the version doesn't really matter, your request
or response objects get transferred around. The same scheme value "https"
works for all versions. Under the hood there's lots of differences and
complexity of course. The Fetch API feels about the right layer of
abstraction for most purposes.

My sense so far has been that QUIC  is providing unique qualities that the
MoQ protocol (whatever it is) wants to harness. If that's true, HTTP/3 is a
hard requirement of an HTTP-based MoQ protocol, then we'd have work to do
in the web platform to ensure its abstractions don't get in the way.
Likewise, implementation details like internal stacks, layering, security
model etc would need to be considered. This isn't an impossible task but
nor will it just happen without investment and engagement.

Cheers
Lucas