Re: [Moq] Encrypted Media Metadata

Hi, Glenn,

 (I swear I'll get the spelling and order of your name correctly, before
MOQ delivers all of its documents and concludes. Please accept my apologies
for my most recent failure. But I digress 🙃)

On Sun, Jul 17, 2022 at 8:10 AM Deen, Glenn <Glenn_Deen=
40comcast.com@dmarc.ietf.org> wrote:

> I get the sense from the proposed charter Media Metadata is currently
> treated sort of monolithically in terms of access to it, its
> encryptability, and its use in different workflows.  Metadata is quite rich
> as a part of the media delivery workflow and is getting increasingly
> important and extensive as media transport and media types evolve.  I
> propose that it needs more specific focus in the group.
>
>
>
> Metadata data and access to it is something that maybe should be
> considered a distinct type of media content on its own along with having
> distinct from the transported media authenticated access and encryption
> considerations that are independent of the media being transported.
>
>
>
> This could possibly be part of the “coordinated or cooperative” middle
> boxes that Lucas has mentioned in his not on the thread “Re: [Moq] "MoQ
> Architecture" question from Spencer's mail”
>
>
>
> Metadata should be more distinctly mentioned in the charter along with
> perhaps a couple of documents that specifically cover Metadata
> authentication and encryption and Metadata Use Cases by both end points and
> middle boxes.
>

After chewing on review team comments on
https://datatracker.ietf.org/doc/html/draft-ietf-mops-streaming-opcons-10
during IETF Last Call, I convinced myself (and, possibly, Jake and Ali 😇),
that it was extremely confusing to keep using the words "transport
protocol" to describe multiple things in that version of the draft,
especially if (for instance) QUIC was the transport protocol directly under
the media sometimes, but was underneath HTTP/3 other times, and underneath
WebTransport *AND *HTTP/3, still other times.

In -11, I had added
https://www.ietf.org/archive/id/draft-ietf-mops-streaming-opcons-11.html#name-transport-protocol-behaviors,
which might be worth taking a look at. It distinguishes between the actual
segments of media, the media format, the protocol immediately under the
media format, and any other transport protocols that make up the protocol
stack.

          Media Segments
    ---------------------------
           Media Format
    ---------------------------
      Media Transport Protocol
    ---------------------------
       Transport Protocol(s)

(additional details in that section of the draft, of course)

If this is unhelpful, my apologies in advance, but I think there are two
mappings for what's in the MOQ charter on July 18 (my time zone):

          Media Segments
    ---------------------------
           Media Format
    ---------------------------
      Media Transport Protocol - MOQ
    ---------------------------
       Transport Protocol(s) - WebTransport-HTTP/3-QUIC

and

          Media Segments
    ---------------------------
           Media Format
    ---------------------------
      Media Transport Protocol - MOQ
    ---------------------------
       Transport Protocol(s) - QUIC

and the relevant points for the MOQ charter discussion might include
protocol stacks like

          Media Segments
    ---------------------------
           Media Format - including the metadata I think you're talking
about
          (so accessible to media-level optimizations like transcoding)
    ---------------------------
      Media Transport Protocol - MOQ, encrypted from MOQ entity to MOQ
entity
          (so, accessible for MOQ-level optimizations like relaying and
caching)
    ---------------------------
       Transport Protocol(s) - QUIC, encrypted from QUIC entity to QUIC
entity

Is this headed the right direction for what you're envisioning with
more-granular metadata, that only needs to be available for media-level
optimization, access control, and whatnot? Is it supportive for metadata
getting "more specific focus in the group"?

(And, if Section 6 in
https://www.ietf.org/archive/id/draft-ietf-mops-streaming-opcons-11.html is
generally a Bad Idea, we should probably mention that on the MOPS mailing
list as well!)

Best,

Spencer

-glenn
> --
> Moq mailing list
> Moq@ietf.org
> https://www.ietf.org/mailman/listinfo/moq
>