[Webtransport] Does WebTransport need a reliable, in-order message abstraction? (fwd)

[Bernard Aboba <[e-mail]>]

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---------- Forwarded message ----------
From: Alan Frindell <[e-mail]>
To: Webtransport <[e-mail]>
Cc:
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Date: Fri, 24 Jul 2020 21:30:45 +0000
Subject: Does WebTransport need a reliable, in-order message abstraction?


I was reviewing the WebSocket specification, and realized there is a gap
that is not currently covered in the overview of WebTransport: reliable,
in-order messages.



The three ways to send messages in WebTransport are:



1) message per datagram, which is unreliable and unordered (and has a lower
maximum size than WebSockets)

2) message per stream, which is reliable but not ordered

3) multiple messages per stream, which is reliable and ordered, but not
framed



A developer either needs to implement their own framing layer on top of a
WebTransport stream (perhaps WebSocket over WebTransport?), or use message
per stream and handle buffering and ordering of messages at a higher layer.



Is replacing WebSockets with WebTransport one of our goals?  If so, I think
we need to address the gap by adding this abstraction.  If not, we should
explicitly mention that this abstraction doesn’t exist, and instruct
developers to use WebSocket instead.



-Alan