Re: Standard for upgrading based on URL?

Upgrading a connection from HTTP/1 to HTTP/3 isn't possible since they use
different underlying transports (TCP vs QUIC).

What would be the use case for starting a TLS connection using HTTP/1 and
then later upgrading to HTTP/2, instead of always using HTTP/2 on the
connection? The in-band upgrade mechanism provided for h2c only exists so
that a client without prior knowledge can use h2c; a similar mechanism
isn't needed for h2 (over TLS) because the signal that HTTP/2 is supported
is carried in ALPN.

On Tue, Oct 12, 2021 at 1:09 PM Ben Schwartz <bemasc@google.com> wrote:

> Clients generally upgrade to HTTP/2 automatically based on the ALPN
> process in the TLS handshake.  Do you mean HTTP/3?
>
> On Tue, Oct 12, 2021 at 1:30 PM Felipe Gasper <felipe@felipegasper.com>
> wrote:
>
>> Hello,
>>
>>         Is there any way, per currently-published standards, to upgrade a
>> TLS connection from HTTP/1 to H2 based on its URL? e.g.:
>>
>> https://example.com/http1   <-- served via HTTP/1
>>
>> https://example.com/http2   <-- served via HTTP/3
>>
>>         This is possible with non-TLS via normal HTTP upgrades but
>> doesn’t appear to be possible via the ALPN approach mandated for
>> TLS-secured HTTP/2 connections. It seems strange that there would be no way
>> to do over TLS what’s easy to do in plain text. What am I missing?
>>
>>         Thank you!
>>
>> -FG
>>
>