Re: Unbound DATA frames in HTTP/3 proposal

From my personal recollection, the main reason we did not ship unbound DATA
frames in the original spec was that we were afraid that if we allow two
ways to spell DATA frames, most implementations would only opt to use the
unbound ones, and that would ossify.

Based on my experience with QUIC performance work in the past, I do believe
that having unbound DATA frames would be beneficial, both from the
bandwidth and from the CPU usage perspective.

On Sat, Oct 4, 2025 at 11:48 PM Mike Bishop <mbishop@evequefou.be> wrote:

> It's been a while and I didn't recall details, so I did a bit of
> spelunking for the history. There was a proposal
> <https://github.com/quicwg/base-drafts/pull/2098> to allow DATA frames
> with length==0 to behave this way, extending to the end of the data stream,
> for all the reasons you cite.  It was merged, but then Martin observed that
> all the discussion of it had been on GitHub, rather than the list, so
> deciding that there had been consensus to merge was improper. We did
> discuss it on the list
> <https://mailarchive.ietf.org/arch/msg/quic/3v2fwQJeWO8m7wYazBPxwRDWl88/>,
> and subsequently reverted it.
>
> This isn't an argument for or against your extension, but do page in the
> history before re-attempting something we decided against previously.
> ------------------------------
> *From:* Yaroslav Rosomakho <yrosomakho@zscaler.com>
> *Sent:* Friday, October 3, 2025 4:42 PM
> *To:* ietf-http-wg@w3.org <ietf-http-wg@w3.org>
> *Cc:* David Schinazi <dschinazi.ietf@gmail.com>
> *Subject:* Unbound DATA frames in HTTP/3 proposal
>
> Dear HTTP Working Group,
>
> While HTTP/3 streams are very efficient for long-term connections such as
> CONNECT, WebSockets and WebTransport, the requirement to encapsulate
> everything into finite-length DATA frames reduces potential performance and
> flexibility. Best case scenario it introduces few extra unnecessary bytes
> on the wire, worst case scenario it can cause an extra memory copy.
>
> David and I would like to propose an optional extension, UNBOUND_DATA
> frame. This frame indicates that the remainder of the stream is data. This
> reduces framing overhead and simplifies transmission of long-lived or
> indeterminate-length payloads.
>
> Feedback and suggestions are very welcome.
>
> Best Regards,
> Yaroslav
>
> ---------- Forwarded message ---------
> A new version of Internet-Draft
> draft-rosomakho-httpbis-h3-unbound-data-00.txt
> has been successfully submitted by Yaroslav Rosomakho and posted to the
> IETF repository.
>
> Name:     draft-rosomakho-httpbis-h3-unbound-data
> Revision: 00
> Title:    Unbound DATA Frames in HTTP/3
> Date:     2025-10-03
> Group:    Individual Submission
> Pages:    8
> URL:
> https://www.ietf.org/archive/id/draft-rosomakho-httpbis-h3-unbound-data-00.txt
> Status:
> https://datatracker.ietf.org/doc/draft-rosomakho-httpbis-h3-unbound-data/
> HTML:
> https://www.ietf.org/archive/id/draft-rosomakho-httpbis-h3-unbound-data-00.html
> HTMLized:
> https://datatracker.ietf.org/doc/html/draft-rosomakho-httpbis-h3-unbound-data
>
>
> Abstract:
>
>    This document defines a new HTTP/3 frame type, UNBOUND_DATA, and a
>    corresponding SETTINGS parameter that enables endpoints to negotiate
>    its use.  When an endpoint sends an UNBOUND_DATA frame on a request
>    or response stream, it indicates that all subsequent octets on that
>    stream are interpreted as data.  This applies both to message body
>    data and to octets transmitted after CONNECT or extended CONNECT.
>    The use of UNBOUND_DATA removes the need to encapsulate each portion
>    of the data in DATA frames, reducing framing overhead and simplifying
>    transmission of long-lived or indeterminate-length payloads.
>
>
>
> The IETF Secretariat
>
>
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