Multiplexing Scheme Updates for QUIC
draft-ietf-avtcore-rfc7983bis-09

[Ballot comment]
Thanks for working on this update.

I don't have any technical comments on this update. However, there is a demand for clarification on QUIC is getting rest of all demux bits and I remember the discussions around it. I think it would be great to document that reasoning in the update.

[Ballot comment]
# GEN AD review of draft-ietf-avtcore-rfc7983bis-08

CC @larseggert

Thanks to Meral Shirazipour for the General Area Review Team (Gen-ART) review
(https://mailarchive.ietf.org/arch/msg/gen-art/-TB__xTB9yrK3hmysj7V6N3tpIc).

## Comments

### Boilerplate

Document boilerplate does not seem to indicate the intended RFC status.

## Nits

All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

### Typos

#### Section 4, paragraph 3
```
-    derivation could be aversely impacted by a vulnerability in the QUIC
+    derivation could be adversely impacted by a vulnerability in the QUIC
+                        +
```

### Boilerplate

Document still refers to the "Simplified BSD License", which was corrected in
the TLP on September 21, 2021. It should instead refer to the "Revised BSD
License".

### Grammar/style

#### Section 2, paragraph 2
```
binding requests have been sent. Therefore a TURN client receiving packets f
                                ^^^^^^^^^
```
A comma may be missing after the conjunctive/linking adverb "Therefore".

#### Section 6.1, paragraph 9
```
/2019/01/rtcquictransport-api> Acknowledgments We would like to thank Martin
                              ^^^^^^^^^^^^^^^
```
Do not mix variants of the same word ("acknowledgment" and "acknowledgement")
within a single text.

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool

[Ballot comment]
Moderate level comments:

(1) p 0, sec 1.  Introduction

  While the scheme described in this document is compatible with QUIC
  version 2 [I-D.ietf-quic-v2], it is not compatible with QUIC bit
  greasing [RFC9287].  As a result, endpoints that wish to use
  multiplexing on their socket MUST NOT send the grease_quic_bit
  transport parameter.

I'm slightly nervous with the aspect of this document that seemingly relies on the format of the first byte in the QUIC short and long header when my understanding is that isn't actually stable across QUIC versions beyond the first bit.  E.g., RFC 8999, sections 5.1 and 5.2 indicate that the first bit of QUIC headers is invariant across versions, but the next 7 bits are version specific.  As such, I think that it would be helpful for the introduction (and perhaps abstract) to have very clearer text to indicate that this standard is compatible with QUIC versions 1 and 2.  It MAY also be compatible with future versions of QUIC, but those future versions MUST be evaluated to see whether any of the version specific bits in the first byte have changed in such a way that they are incompatible with this demux scheme.



Minor level comments:

(2) p 0, sec 2.  Multiplexing of TURN Channels

  In the absence of QUIC bit greasing, the first octet of a QUIC packet
  (e.g. a short header packet in QUIC v1 or v2) may fall in the range
  64 to 127, thereby overlapping with the allocated range for TURN
  channels of 64 to 79.

I don't know QUIC very well, but it wasn't obvious to me why the text above specifically applies to the short header packet and not also the long header packet.

[Ballot comment]

# Éric Vyncke, INT AD, comments for draft-ietf-avtcore-rfc7983bis-08
CC @evyncke

Thank you for the work put into this document.

Please find below some non-blocking COMMENT points (but replies would be appreciated even if only for my own education) including one about the lack of extensions.

Special thanks to Jonathan Lennox for the shepherd's detailed write-up including the WG consensus **and** the justification of the intended status.

Other thanks to Bernie Volz, the Internet directorate reviewer (at my request), for this int-dir review:
https://datatracker.ietf.org/doc/review-ietf-avtcore-rfc7983bis-08-intdir-telechat-volz-2023-02-03/

I hope that this review helps to improve the document,

Regards,

-éric

## COMMENTS

### ZRTP

May I assume that "ZRTP" is not an acronym (based on Zimmerman being an author ?), hence there is no expansion of "ZRTP" in the text ?

### Section 1

Perhaps add the title of RFC 5764 to be consistent with other RFCs having a title/short description ?

### Why not a IANA registry ?

Out of curiosity... The train has left the station of course, but I wonder why the use of the first octet is not specified in a IANA registry rather than in a set of RFCs.

### No extension points ?

The new text specifies actions/protocols for **all** 256 values of the first octet. Are we sure that we can 'burn' all those code points with a vast majority of them for QUIC ? While I trust AVTCORE chair and the responsible AD, I really want to get an answer on this question. To be honest, I was about to raise a DISCUSS.

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues.

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments

IANA understands from the authors that references in the TLS ContentType registry should be replaced with references to this document. This action should be added to the document's IANA Considerations section.

[Ballot comment]
Thanks to Yoshi for the TSVART review.

It appears you've addressed the actionable item in that review, but please respond to his other questions on the list.

Request for Last Call review by TSVART Completed: Ready with Nits. Reviewer: Yoshifumi Nishida. Sent review to list. Submission of review completed at an earlier date.

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Functions Operator has reviewed draft-ietf-avtcore-rfc7983bis-07, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Specialist

The following Last Call announcement was sent out (ends 2023-01-17):

From: The IESG
To: IETF-Announce
CC: avt@ietf.org, avtcore-chairs@ietf.org, draft-ietf-avtcore-rfc7983bis@ietf.org, jonathan.lennox@8x8.com, superuser@gmail.com
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Multiplexing Scheme Updates for QUIC) to Proposed Standard


The IESG has received a request from the Audio/Video Transport Core
Maintenance WG (avtcore) to consider the following document: - 'Multiplexing
Scheme Updates for QUIC'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2023-01-17. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document defines how QUIC, Datagram Transport Layer Security
  (DTLS), Real-time Transport Protocol (RTP), RTP Control Protocol
  (RTCP), Session Traversal Utilities for NAT (STUN), Traversal Using
  Relays around NAT (TURN), and ZRTP packets are multiplexed on a
  single receiving socket.

  This document updates RFC 7983 and RFC 5764.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-avtcore-rfc7983bis/



No IPR declarations have been submitted directly on this I-D.

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

The document had agreement from a broad variety of participants.
There were comments during WGLC which were accepted and incorporated
into the document.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

One of the authors has indicated that his organization has an
implementation.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

The document is related to work with the QUIC group; it has had
reviews by RTP-knowledgable QUIC experts.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

None.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard.  This document describes behavior which is
necessary for interoperability, and it updates RFCs 7983 and 5764,
both of which are PS.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes.  There are no IPR disclosures.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

One document cited as an I-D has subsequently been published as an
RFC, and two lines are one character two long.  These are both trivial
issues that can be fixed in subsequent revisions or in the RFC Editor's
process.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

The document updates two existing RFCs, but does not change the status
of any.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

N/A.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

None.

# Document Shepherd Write-Up for Group Documents

*This version is dated 4 July 2022.*

Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.

Note that some numbered items contain multiple related questions; please be sure
to answer all of them.

## Document History

1. Does the working group (WG) consensus represent the strong concurrence of a
  few individuals, with others being silent, or did it reach broad agreement?

The document had agreement from a broad variety of participants.
There were comments during WGLC which were accepted and incorporated
into the document.

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

No.

3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
  so, please summarize the areas of conflict in separate email messages to the
  responsible Area Director. (It should be in a separate email because this
  questionnaire is publicly available.)

No.

4. For protocol documents, are there existing implementations of the contents of
  the document? Have a significant number of potential implementers indicated
  plans to implement? Are any existing implementations reported somewhere,
  either in the document itself (as [RFC 7942][3] recommends) or elsewhere
  (where)?

One of the authors has indicated that his organization has an
implementation.

## Additional Reviews

5. Do the contents of this document closely interact with technologies in other
  IETF working groups or external organizations, and would it therefore benefit
  from their review? Have those reviews occurred? If yes, describe which
  reviews took place.

The document is related to work with the QUIC group; it has had
reviews by RTP-knowledgable QUIC experts.

6. Describe how the document meets any required formal expert review criteria,
  such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.

N/A.

7. If the document contains a YANG module, has the final version of the module
  been checked with any of the [recommended validation tools][4] for syntax and
  formatting validation? If there are any resulting errors or warnings, what is
  the justification for not fixing them at this time? Does the YANG module
  comply with the Network Management Datastore Architecture (NMDA) as specified
  in [RFC 8342][5]?

N/A.

8. Describe reviews and automated checks performed to validate sections of the
  final version of the document written in a formal language, such as XML code,
  BNF rules, MIB definitions, CBOR's CDDL, etc.

## Document Shepherd Checks

9. Based on the shepherd's review of the document, is it their opinion that this
  document is needed, clearly written, complete, correctly designed, and ready
  to be handed off to the responsible Area Director?

Yes.

10. Several IETF Areas have assembled [lists of common issues that their
    reviewers encounter][6]. For which areas have such issues been identified
    and addressed? For which does this still need to happen in subsequent
    reviews?

None.

11. What type of RFC publication is being requested on the IETF stream ([Best
    Current Practice][12], [Proposed Standard, Internet Standard][13],
    [Informational, Experimental or Historic][14])? Why is this the proper type
    of RFC? Do all Datatracker state attributes correctly reflect this intent?

Proposed Standard.  This document describes behavior which is
necessary for interoperability, and it updates RFCs 7983 and 5764,
both of which are PS.


12. Have reasonable efforts been made to remind all authors of the intellectual
    property rights (IPR) disclosure obligations described in [BCP 79][7]? To
    the best of your knowledge, have all required disclosures been filed? If
    not, explain why. If yes, summarize any relevant discussion, including links
    to publicly-available messages when applicable.

Yes.  There are no IPR disclosures.

13. Has each author, editor, and contributor shown their willingness to be
    listed as such? If the total number of authors and editors on the front page
    is greater than five, please provide a justification.

Yes.

14. Document any remaining I-D nits in this document. Simply running the [idnits
    tool][8] is not enough; please review the ["Content Guidelines" on
    authors.ietf.org][15]. (Also note that the current idnits tool generates
    some incorrect warnings; a rewrite is underway.)

One document cited as an I-D has subsequently been published as an
RFC, and two lines are one character two long.  These are both trivial
issues that can be fixed in subsequent revisions or in the RFC Editor's
process.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

No.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

None.

17. Are there any normative downward references (see [RFC 3967][9] and [BCP
    97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
    list them.

None.

18. Are there normative references to documents that are not ready to be
    submitted to the IESG for publication or are otherwise in an unclear state?
    If so, what is the plan for their completion?

None.

19. Will publication of this document change the status of any existing RFCs? If
    so, does the Datatracker metadata correctly reflect this and are those RFCs
    listed on the title page, in the abstract, and discussed in the
    introduction? If not, explain why and point to the part of the document
    where the relationship of this document to these other RFCs is discussed.

The document updates two existing RFCs, but does not change the status
of any.

20. Describe the document shepherd's review of the IANA considerations section,
    especially with regard to its consistency with the body of the document.
    Confirm that all aspects of the document requiring IANA assignments are
    associated with the appropriate reservations in IANA registries. Confirm
    that any referenced IANA registries have been clearly identified. Confirm
    that each newly created IANA registry specifies its initial contents,
    allocations procedures, and a reasonable name (see [RFC 8126][11]).

N/A.

21. List any new IANA registries that require Designated Expert Review for
    future allocations. Are the instructions to the Designated Expert clear?
    Please include suggestions of designated experts, if appropriate.

None.