Re: RFC 9114 - HTTP/3 and quic stream behavior

Hi Kaushal,

+ the HTTP WG

Responses in line:

On Sun, 12 Mar 2023, 16:12 Kaushal Bhandankar, <kaushalgoa@gmail.com> wrote:

>
> I have a few questions on the Http/3 specification related to QUIC streams
> behavior
>
> 1. Can a single file download ( index.html or file.pdf ) happen on
> multiple parallel quic streams ?
>

A single HTTP/3 request/response exchange occurs over one QUIC stream. So a
request for a whole object would take place over one stream, and all its
response data would be delivered over it.

In theory, you could perform parallel requests for different ranges of the
same resource, which would occur over different streams. But those streams
would have to share the same connection, so I doubt that it would improve
anything.

There is no standard facility to split the responses to a single requests
over multiple streams. I'm not sure that would be useful given the shared
connection.

2. What happens when the limits of initial_max_stream_data_bidi_remote
> or initial_max_stream_data_uni are exceeded ? Does the file download
> continue on a new stream which gets opened ?
>

Probably answered by my response to (1). More generally, if the client
can't make a request due to stream limit of client-initiated bidirectional
streams, its progress is blocked. Servers probably want to avoid that
happening in the general case but restriction of concurrent streams is
useful as a tool to manage resource commitments.

Cheers
Lucas


> Regards,
> Kaushal
>