Some applications running on top of QUIC send an identifier at the beginning of
the stream in order to associate that stream with a specific subcomponent of the
application. For example, WebTransport ({{!WEBTRANSPORT}}) uses a
variable-length encoded integer to associate a stream with a particular
WebTransport session. It is desirable that the receiver is able to associate
incoming streams with their respective subcomponent of the application, even if
the QUIC stream is reset before the identifier at the beginning of the stream
was read by the application.
Actual use cases for protocol extensions are good. I think the WebTransport normative reference is just an accident and we can make it informative (even if that ends up as a downref, it's adopted work we expect to be published someday).
I think we can tweak this text a little bit to make the extension sound as generic as it is, and then speak to the concrete examples. I'll make a PR.
The intro states:
Actual use cases for protocol extensions are good. I think the WebTransport normative reference is just an accident and we can make it informative (even if that ends up as a downref, it's adopted work we expect to be published someday).
I think we can tweak this text a little bit to make the extension sound as generic as it is, and then speak to the concrete examples. I'll make a PR.