Extensible Prioritization Scheme for HTTP
draft-ietf-httpbis-priority-12

Proto write-up for draft-ietf-pce-interas-pcecp-reqs-06.txt

Intended status : Informational Track

> (1.a)  Who is the Document Shepherd for this document?  Has the
>        Document Shepherd personally reviewed this version of the
>        document and, in particular, does he or she believe this
>        version is ready for forwarding to the IESG for publication?

JP Vasseur is the document shepherd. Both co-chairs (JP Vasseur and Adrian
Farrel) have reviewed the document. They think that the document is ready to
be forwarded to the IESG for publication.

> (1.b)  Has the document had adequate review both from key WG members
>        and from key non-WG members?  Does the Document Shepherd have
>        any concerns about the depth or breadth of the reviews that
>        have been performed?


The document has been discussed and reviewed by several key WG members.
Further, Sandy Murphy from the Security Directorate made a thorough review
of the document
(http://www.ietf.org/mail-archive/web/pce/current/msg01393.html) and Adrian
Farrel has worked with the authors to address the comments.

> (1.c)  Does the Document Shepherd have concerns that the document
>        needs more review from a particular or broader perspective,
>        e.g., security, operational complexity, someone familiar with
>        AAA, internationalization or XML?

No concerns.

> (1.d)  Does the Document Shepherd have any specific concerns or
>        issues with this document that the Responsible Area Director
>        and/or the IESG should be aware of?  For example, perhaps he
>        or she is uncomfortable with certain parts of the document, or
>        has concerns whether there really is a need for it.  In any
>        event, if the WG has discussed those issues and has indicated
>        that it still wishes to advance the document, detail those
>        concerns here.  Has an IPR disclosure related to this document
>        been filed?  If so, please include a reference to the
>        disclosure and summarize the WG discussion and conclusion on
>        this issue.

No specific concern about this document. The requirements expressed in this
document had a good support in the WG and complement the generic
requirements for the PCECP defined in RFC4657.

There was no filed IPR disclosure related to this document.

> (1.e)  How solid is the WG consensus behind this document?  Does it
>        represent the strong concurrence of a few individuals, with
>        others being silent, or does the WG as a whole understand and
>        agree with it?

Good consensus. No concern or additional comments received during WG Last
Call.

> (1.f)  Has anyone threatened an appeal or otherwise indicated extreme
>        discontent?  If so, please summarise the areas of conflict in
>        separate email messages to the Responsible Area Director.  (It
>        should be in a separate email because this questionnaire is
>        entered into the ID Tracker.)

No threats. No discontent.

> (1.g)  Has the Document Shepherd personally verified that the
>        document satisfies all ID nits?  (See
>        http://www.ietf.org/ID-Checklist.html and
>        http://tools.ietf.org/tools/idnits/).  Boilerplate checks are
>        not enough; this check needs to be thorough.  Has the document
>        met all formal review criteria it needs to, such as the MIB
>        Doctor, media type and URI type reviews?

The Document has been checked.

> (1.h)  Has the document split its references into normative and
>        informative?  Are there normative references to documents that
>        are not ready for advancement or are otherwise in an unclear
>        state?  If such normative references exist, what is the
>        strategy for their completion?  Are there normative references
>        that are downward references, as described in [RFC3967]?  If
>        so, list these downward references to support the Area
>        Director in the Last Call procedure for them [RFC3967].

References split.
No downrefs.

> (1.i)  Has the Document Shepherd verified that the document IANA
>        consideration section exists and is consistent with the body
>        of the document?  If the document specifies protocol
>        extensions, are reservations requested in appropriate IANA
>        registries?  Are the IANA registries clearly identified?  If
>        the document creates a new registry, does it define the
>        proposed initial contents of the registry and an allocation
>        procedure for future registrations?  Does it suggest a
>        reasonable name for the new registry?  See [RFC2434].  If the
>        document describes an Expert Review process has Shepherd
>        conferred with the Responsible Area Director so that the IESG
>        can appoint the needed Expert during the IESG Evaluation?

This document makes no requests for IANA action

> (1.j)  Has the Document Shepherd verified that sections of the
>        document that are written in a formal language, such as XML
>        code, BNF rules, MIB definitions, etc., validate correctly in
>        an automated checker?

No such formal language is used.

> (1.k)  The IESG approval announcement includes a Document
>        Announcement Write-Up.  Please provide such a Document
>        Announcement Write-Up.  Recent examples can be found in the
>        "Action" announcements for approved documents.  The approval
>        announcement contains the following sections:
>
>        Technical Summary
>          Relevant content can frequently be found in the abstract
>          and/or introduction of the document.  If not, this may be
>          an indication that there are deficiencies in the abstract
>          or introduction.

[RFC4216] defines the scenarios motivating the deployment of inter-AS
  Multiprotocol Label Switching Traffic Engineering (MPLS TE) and
  specifies the requirements for inter-AS MPLS TE when the ASes are
  under the administration of one Service Provider (SP) or the
  administration of different SPs.

  Three signaling options are defined for setting up an inter-AS TE
  LSP:
      1) contiguous TE LSP as documented in [RFC5151];
      2) stitched inter-AS TE LSP discussed in [RFC5150];
      3) nested TE LSP as in [RFC4206].

  [RFC5152] defines mechanisms for the computation of inter-domain TE
  Label Switched Paths (LSPs) using network elements along the
  signaling paths to compute per-domain constrained path segments. The
  mechanisms in [RFC5152] do not guarantee an optimum constrained path
  across multiple ASes where an optimum path for an TE LSP is one that
  has the smallest cost, according to a normalized TE metric (based
  upon a TE metric or Interior Gateway Protocol (IGP) metric adopted
  in each transit AS) among all possible paths that satisfy the LSP TE
  constraints.

  The Path Computation Element (PCE) [RFC4655] is a component that is
  capable of computing paths for MPLS TE and Generalized Multiprotcol
  Label Switching Protocol ((G)MPLS TE) LSPs. The requirements for a
  PCE have come from SP demands to compute optimum constrained paths
  across multiple areas and/or domains, and to be able to separate the
  path computation elements from the forwarding elements.

  The PCE Communication Protocol (PCEP) is defined to allow
  communication between Path Computation Clients (PCCs) and PCEs, and
  between PCEs. The PCEP is used to request (G)MPLS TE paths and to
  supply computed paths in response. Generic requirements for the
  PCEP are discussed in [RFC4657]. This document provides a set of
  PCEP requirements that are specific to inter-AS (G)MPLS TE path
  computation.

>        Working Group Summary
>          Was there anything in WG process that is worth noting?  For
>          example, was there controversy about particular points or
>          were there decisions where the consensus was particularly
>          rough?

The PCE WG has good consensus with no disagreement.


>        Document Quality
>          Are there existing implementations of the protocol?  Have a
>          significant number of vendors indicated their plan to
>          implement the specification?  Are there any reviewers that
>          merit special mention as having done a thorough review,
>          e.g., one that resulted in important changes or a
>          conclusion that the document had no substantive issues?  If
>          there was a MIB Doctor, Media Type or other expert review,
>          what was its course (briefly)?  In the case of a Media Type
>          review, on what date was the request posted?

draft-ietf-pce-interas-pcecp-reqs-06.txt is a requirement document.Trammell, et al.            Standards Track                  [Page 26]
RFC 7015                    IPFIX Aggregation            September 2013

7.3.  Distinct Host Export

  The following six Information Elements represent the distinct counts
  of source and destination network-layer addresses used to export
  distinct host counts reduced away during key aggregation.

7.3.1.  distinctCountOfSourceIPAddress

  Description:  The count of distinct source IP address values for
      Original Flows contributing to this Aggregated Flow, without
      regard to IP version.  This Information Element is preferred to
      the IP-version-specific counters, unless it is important to
      separate the counts by version.

  Abstract Data Type:  unsigned64

  Data Type Semantics:  totalCounter

  ElementID:  378

7.3.2.  distinctCountOfDestinationIPAddress

  Description:  The count of distinct destination IP address values for
      Original Flows contributing to this Aggregated Flow, without
      regard to IP version.  This Information Element is preferred to
      the version-specific counters below, unless it is important to
      separate the counts by version.

  Abstract Data Type:  unsigned64

  Data Type Semantics:  totalCounter

  ElementID:  379

7.3.3.  distinctCountOfSourceIPv4Address

  Description:  The count of distinct source IPv4 address values for
      Original Flows contributing to this Aggregated Flow.

  Abstract Data Type:  unsigned32

  Data Type Semantics:  totalCounter

  ElementID:  380

Trammell, et al.            Standards Track                  [Page 27]
RFC 7015                    IPFIX Aggregation            September 2013

7.3.4.  distinctCountOfDestinationIPv4Address

  Description:  The count of distinct destination IPv4 address values
      for Original Flows contributing to this Aggregated Flow.

  Abstract Data Type:  unsigned32

  Data Type Semantics:  totalCounter

  ElementID:  381

7.3.5.  distinctCountOfSourceIPv6Address

  Description:  The count of distinct source IPv6 address values for
      Original Flows contributing to this Aggregated Flow.

  Abstract Data Type:  unsigned64

  Data Type Semantics:  totalCounter

  ElementID:  382

7.3.6.  distinctCountOfDestinationIPv6Address

  Description:  The count of distinct destination IPv6 address values
      for Original Flows contributing to this Aggregated Flow.

  Abstract Data Type:  unsigned64

  Data Type Semantics:  totalCounter

  ElementID:  383

7.4.  Aggregate Counter Distribution Export

  When exporting counters distributed among Aggregated Flows, as
  described in Section 5.1.1, the Exporting Process MAY export an
  Aggregate Counter Distribution Option Record for each Template
  describing Aggregated Flow records; this Options Template is
  described below.  It uses the valueDistributionMethod Information
  Element, also defined below.  Since, in many cases, distribution is
  simple, accounting the counters from Contributing Flows to the first
  Interval to which they contribute, this is the default situation, for
  which no Aggregate Counter Distribution Record is necessary;
  Aggregate Counter Distribution Records are only applicable in more
  exotic situations, such as using an Aggregation Interval smaller than
  the durations of Original Flows.

Trammell, et al.            Standards Track                  [Page 28]
RFC 7015                    IPFIX Aggregation            September 2013

7.4.1.  Aggregate Counter Distribution Options Template

  This Options Template defines the Aggregate Counter Distribution
  Record, which allows the binding of a value distribution method to a
  Template ID.  The scope is the Template ID, whose uniqueness, per
  [RFC7011], is local to the Transport Session and Observation Domain
  that generated the Template ID.  This is used to signal to the
  Collecting Process how the counters were distributed.  The fields are
  as below:

  +-----------------------------+-------------------------------------+
  | IE                          | Description                        |
  +-----------------------------+-------------------------------------+
  | templateId [scope]          | The Template ID of the Template    |
  |                            | defining the Aggregated Flows to    |
  |                            | which this distribution option      |
  |                            | applies.  This Information Element |
  |                            | MUST be defined as a Scope field.  |
  | valueDistributionMethod    | The method used to distribute the  |
  |                            | counters for the Aggregated Flows  |
  |                            | defined by the associated Template. |
  +-----------------------------+-------------------------------------+

7.4.2.  valueDistributionMethod Information Element

  Description:  A description of the method used to distribute the
      counters from Contributing Flows into the Aggregated Flow records
      described by an associated scope, generally a Template.  The
      method is deemed to apply to all the non-Key Information Elements
      in the referenced scope for which value distribution is a valid
      operation; if the originalFlowsInitiated and/or
      originalFlowsCompleted Information Elements appear in the
      Template, they are not subject to this distribution method, as
      they each infer their own distribution method.  This is intended
      to be a complete set of possible value distribution methods; it is
      encoded as follows:

[Ballot comment]
Thanks to Maria Ines Robles for their General Area Review Team (Gen-ART) review
(https://mailarchive.ietf.org/arch/msg/gen-art/k0c2L3WOP5A_dxSAHzy6PkmoHvw).

-------------------------------------------------------------------------------
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.

Section 1. , paragraph 3, nit:
> have their own needs that are independent from client needs, so they often co
>                              ^^^^^^^^^^^^^^^^
The usual collocation for "independent" is "of", not "from". Did you mean
"independent of"?

Section 1. , paragraph 4, nit:
> s as input into prioritization decision making. The design and implementatio
>                                ^^^^^^^^^^^^^^^
The noun "decision-making" (= the process of deciding something) is spelled
with a hyphen.

Section 5. , paragraph 4, nit:
> ream, allowing them to be sent independent from the stream that carries the r
>                                ^^^^^^^^^^^^^^^^
The usual collocation for "independent" is "of", not "from". Did you mean
"independent of"?

Section 7.2. , paragraph 9, nit:
> ded value. This is different from the the request header field, in which omi
>                                  ^^^^^^^
Two determiners in a row. Choose either "the" or "the".

Section 8. , paragraph 9, nit:
>  SHOULD be served by sharing bandwidth amongst them. Incremental resources a
>                                    ^^^^^^^
Do not mix variants of the same word ("amongst" and "among") within a single
text.

Section 10. , paragraph 3, nit:
> t generation order might lead to sub-optimal results at the client, as early
>                                  ^^^^^^^^^^^
This word is normally spelled as one.

Section 13.2. , paragraph 2, nit:
> n registers the following entry in the the Hypertext Transfer Protocol (HTTP)
>                                    ^^^^^^^
Two determiners in a row. Choose either "the" or "the".

These URLs point to tools.ietf.org, which is being deprecated:
* http://tools.ietf.org/agenda/83/slides/slides-83-httpbis-5.pdf

[Ballot comment]
Kudos on another well done document.

While it's certainly not necessary, I suggest that Section 16 be broken up into one subsection for each IANA action being requested.

[Ballot comment]
Thanks for another well-written and easy-to-read document from the
HTTPBIS WG!

Many thanks to Bob Briscoe for the detailed tsv-art review, and to the
authors for the updates and responses to him.
Thanks as well to Robert Sparks for the secdir review.

I put my editorial suggestions in
https://github.com/httpwg/http-extensions/pull/1861 (to the extent that
I have concrete suggestions).

Section 4

  Intermediaries can consume and produce priority signals in a
  PRIORITY_UPDATE frame or Priority header field.  Sending a
  PRIORITY_UPDATE frame preserves the signal from the client, but
  provides a signal that overrides that for the next hop; see
  Section 14.  [...]

I'm having a bit of trouble following "provides a signal that overrides
that for the next hop"; is the "that" in "overrides that" referring to
"the signal from the client"?  Is the "signal that overrides" referring
to the PRIORITY_UPDATE frame emitted by the intermediary in question?
That seems to set us up for a scenario where the same frame is both
preserving and overriding the signal from the client, which doesn't make
much sense.  Is it perhaps that "when used by downstream intermediaries,
this mechanism would override the signal from the client, even though
the current intermediary under discussion has preserved the signal from
the client"?

Section 4.3.1

  When reviewing registration requests, the designated expert(s) can
  consider the additional guidance provided in Section 4.3 but cannot
  use it as a basis for rejection.

That seems to invite the question of what *can* be used as a basis for
rejection?  Or is the presence of any written specification sufficient
to trigger a "shall-issue" registration?

Section 7

  Servers SHOULD buffer the most recently received PRIORITY_UPDATE
  frame and apply it once the referenced stream is opened.  Holding
  PRIORITY_UPDATE frames for each stream requires server resources,
  which can can be bounded by local implementation policy.  [...]

Just to confirm my understanding: this local policy being described
would be distinct from the limit on the number of streams that the
client is allowed to open (which would also serve as a limit on the
amount of resources committed to storing priority information), right?

Section 9

  A client MAY use priority values to make local processing or
  scheduling choices about the requests it initiates.

Are the values in question here the server-generated response priority
values (used to affect future requests) or the client's own generated
priority values (used to affect those same requests)?

[Ballot comment]
Thank you for the work put into this document. It is really easy to read and it should bring real values.

Please find below some non-blocking COMMENT points (but replies would be appreciated even if only for my own education).

Special thanks to Tommy Pauly for the shepherd's write-up including the section about the WG consensus.

I hope that this helps to improve the document,

Regards,

-éric

I like the way that urgency and incremental are defined and used.

-- Section 4.1 --
Please bear with my lack of knowledge here, but I wonder what is the expected client behaviour in the absence of SETTINGS_NO_RFC7540_PRIORITIES ? Should it keep using the 2 priority signals ?

I also wonder about the asymmetry between the 2nd and 3rd paragraph, i.e., may the client continue to send both priority signales in the 2nd paragraph ?

-- Section 4.3 --
Should the 'community' be defined in "cannot be agreed upon in the community" ?

-- Section 6 --
Does the describe used of u=7 contradict the one described earlier as "delivery of software updates" in section 4.1 ? Perhaps add the pre-fetch use case in section 4.1 ?

-- Section 7.1 --
Should this be "Type (i) = 0x10" in the figure 1 to match the text "(type=0x10)" in the first paragraph ?

[Ballot comment]
Thanks for working on the HTTP priority. I hope to see this specification gets deployed and we learn how to efficiently use priorities more.

I have two comments that might have been already thought about -

  - Section 12: I was wondering how much it would be different to have same considerations for TCP as we have for QUIC - specially for "Endpoints SHOULD prioritize retransmission of data over sending new data, unless priorities specified by the application indicate otherwise". Could this be a very transport agnostic behavior this specification can define?

  - Section 13.1 : it says  -

      "if a server knows the intermediary is coalescing requests, then it could avoid serving the responses in their entirety and instead distribute bandwidth (for example, in a round-robin manner)"

    It would be great if we can mention any known or standard way for the servers to know about the intermediary. If there is non or if the is not deterministic way for the server to learn about how the intermediary works then I would argue that Section 13.1 is an unnecessary details.

[Ballot comment]
Thanks to Bob Briscoe for the (extensive) TSVART review. From the thread, it looks like you have mostly addressed his concerns.

Bob's question about the definition of fairness probably relates to the rich literature on this topic -- it's a bit more complicated than every connection getting the same bandwidth: https://en.wikipedia.org/wiki/Fairness_measure. It might be good to say exactly what you mean instead of falling back on the term of art, which carries a bit more complexity than I think you're asking for. But I think the considerations you have in Sec 13 are solid.

It's interesting that PRIORITY_UPDATE cannot be sent by the server. Is it conceivable that processing of the request could lead to late change in the priority of different objects.

The Expert Review for http-fields and http2-parameters are OK.  Waiting on experts to be designated for HTTP/3 Frame Types registry for the final expert review to be completed.

(Via drafts-lastcall-comment@iana.org): Correction to the below review.

The HTTP/2 Frame Type registry registration does not require Expert Review as it is a IETF Review or IESG Approval registry.

Best regards,

Michelle Cotton
IANA Services


On Mon Nov 29 16:52:01 2021, michelle.cotton wrote:
>
> IESG/Authors/WG Chairs:
>
> The IANA Functions Operator has completed its review of draft-ietf-
> httpbis-priority-09. If any part of this review is inaccurate, please
> let us know.
>
> The IANA Functions Operator has a question about one of the actions
> requested in the IANA Considerations section of this document.
>
> The IANA Functions Operator understands that, upon approval of this
> document, there are five actions which we must complete.
>
> First, in the Hypertext Transfer Protocol (HTTP) Field Name Registry
> located at:
>
> https://www.iana.org/assignments/http-fields/
>
> a single, new registration will be made as follows:
>
> Field Name: Priority
> Template:
> Status: permanent
> Reference: [ RFC-to-be ]
> Comments:
>
> As this document requests registrations in an Expert Review or
> Specification Required (see RFC 8126) registry, we will initiate the
> required Expert Review via a separate request. This review must be
> completed before the document's IANA state can be changed to "IANA
> OK."
>
> Second, in the HTTP/2 Settings registry on the Hypertext Transfer
> Protocol version 2 (HTTP/2) Parameters registry page located at:
>
> https://www.iana.org/assignments/http2-parameters/
>
> Code: 0x9
> Name: SETTINGS_NO_RFC7540_PRIORITIES
> Initial Value: 0
> Reference: [ RFC-to-be ]
>
> As this also requests registrations in an Expert Review or
> Specification Required (see RFC 8126) registry, we will initiate the
> required Expert Review via a separate request. This review must be
> completed before the document's IANA state can be changed to "IANA
> OK."
>
> Third, in the HTTP/2 Frame Type registry also on the Hypertext
> Transfer Protocol version 2 (HTTP/2) Parameters registry page located
> at:
>
> https://www.iana.org/assignments/http2-parameters/
>
> a single, new registration will be made as follows:
>
> Code: 0x10
> Frame Type: PRIORITY_UPDATE
> Reference: [ RFC-to-be ]
>
> As this also requests registrations in an Expert Review or
> Specification Required (see RFC 8126) registry, we will initiate the
> required Expert Review via a separate request. This review must be
> completed before the document's IANA state can be changed to "IANA
> OK."
>
> Fourth, in the HTTP/3 Frame Types registry on the Hypertext Transfer
> Protocol version 3 (HTTP/3) registry page located at:
>
> https://www.iana.org/assignments/http3-parameters/
>
> two, new registrations will be made as follows:
>
> Value: 0xF0700
> Frame Type: PRIORITY_UPDATE
> Status: permanent
> Specification: [ RFC-to-be ]
> Date: [ TBD-at-Registration ]
> Change Controller: IETF
> Contact: [HTTP_WG]
>
> Value: 0xF0701
> Frame Type: PRIORITY_UPDATE
> Status: permanent
> Specification: [ RFC-to-be ]
> Date: [ TBD-at-Registration ]
> Change Controller: IETF
> Contact: [HTTP_WG]
>
> As this also requests registrations in an Expert Review or
> Specification Required (see RFC 8126) registry, we will initiate the
> required Expert Review via a separate request. This review must be
> completed before the document's IANA state can be changed to "IANA
> OK."
>
> Fifth, a new registry is to be created called the HTTP Priority
> Parameters registry. The new registry will be located at a new
> registry page:
>
> https://iana.org/assignments/http-priority
>
> The registration rules for the new registry are:
>
> Registration requests for parameters with a key length of one use the
> Specification Required policy, as per Section 4.6 of [RFC8126].
>
> Registration requests for parameters with a key length greater than
> one use the Expert Review policy, as per Section 4.5 of [RFC8126]. A
> specification document is not required.
>
> IANA Question --> IANA understands that there are to be initial
> registrations in the new registry, but Section 4 of [ RFC-to-be ] is
> not explicit about what types should be registered and what the format
> of the registry should be. Could this information be provided?
>
> The IANA Functions Operator understands that these are the only
> actions required to be completed upon approval of this document.
>
> Note:  The actions requested in this document will not be completed
> until the document has been approved for publication as an RFC. This
> message is meant only to confirm the list of actions that will be
> performed.
>
> Thank you,
>
> Michelle Cotton
> IANA Services
>

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

The IANA Functions Operator has completed its review of draft-ietf-httpbis-priority-09. If any part of this review is inaccurate, please let us know.

The IANA Functions Operator has a question about one of the actions requested in the IANA Considerations section of this document.

The IANA Functions Operator understands that, upon approval of this document, there are five actions which we must complete.

First, in the Hypertext Transfer Protocol (HTTP) Field Name Registry located at:

https://www.iana.org/assignments/http-fields/

a single, new registration will be made as follows:

Field Name: Priority
Template:
Status: permanent
Reference: [ RFC-to-be ]
Comments:

As this document requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Second, in the HTTP/2 Settings registry on the Hypertext Transfer Protocol version 2 (HTTP/2) Parameters registry page located at:

https://www.iana.org/assignments/http2-parameters/

Code: 0x9
Name: SETTINGS_NO_RFC7540_PRIORITIES
Initial Value: 0
Reference: [ RFC-to-be ]

As this also requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Third, in the HTTP/2 Frame Type registry also on the Hypertext Transfer Protocol version 2 (HTTP/2) Parameters registry page located at:

https://www.iana.org/assignments/http2-parameters/

a single, new registration will be made as follows:

Code: 0x10
Frame Type: PRIORITY_UPDATE
Reference: [ RFC-to-be ]

As this also requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Fourth, in the HTTP/3 Frame Types registry on the Hypertext Transfer Protocol version 3 (HTTP/3) registry page located at:

https://www.iana.org/assignments/http3-parameters/

two, new registrations will be made as follows:

Value: 0xF0700
Frame Type: PRIORITY_UPDATE
Status: permanent
Specification: [ RFC-to-be ]
Date: [ TBD-at-Registration ]
Change Controller: IETF
Contact: [HTTP_WG]

Value: 0xF0701
Frame Type: PRIORITY_UPDATE
Status: permanent
Specification: [ RFC-to-be ]
Date: [ TBD-at-Registration ]
Change Controller: IETF
Contact: [HTTP_WG]

As this also requests registrations in an Expert Review or Specification Required (see RFC 8126) registry, we will initiate the required Expert Review via a separate request. This review must be completed before the document's IANA state can be changed to "IANA OK."

Fifth, a new registry is to be created called the HTTP Priority Parameters registry. The new registry will be located at a new registry page:

https://iana.org/assignments/http-priority

The registration rules for the new registry are:

Registration requests for parameters with a key length of one use the Specification Required policy, as per Section 4.6 of [RFC8126].

Registration requests for parameters with a key length greater than one use the Expert Review policy, as per Section 4.5 of [RFC8126]. A specification document is not required.

IANA Question --> IANA understands that there are to be initial registrations in the new registry, but Section 4 of [ RFC-to-be ] is not explicit about what types should be registered and what the format of the registry should be. Could this information be provided?

The IANA Functions Operator understands that these are the only actions required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

Thank you,

Michelle Cotton
IANA Services

The following Last Call announcement was sent out (ends 2021-11-29):

From: The IESG
To: IETF-Announce
CC: draft-ietf-httpbis-priority@ietf.org, francesca.palombini@ericsson.com, httpbis-chairs@ietf.org, ietf-http-wg@w3.org, tpauly@apple.com
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Extensible Prioritization Scheme for HTTP) to Proposed Standard


The IESG has received a request from the HTTP WG (httpbis) to consider the
following document: - 'Extensible Prioritization Scheme for HTTP'
  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 2021-11-29. 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 describes a scheme that allows an HTTP client to
  communicate its preferences for how the upstream server prioritizes
  responses to its requests, and also allows a server to hint to a
  downstream intermediary how its responses should be prioritized when
  they are forwarded.  This document defines the Priority header field
  for communicating the initial priority in an HTTP version-independent
  manner, as well as HTTP/2 and HTTP/3 frames for reprioritizing
  responses.  These share a common format structure that is designed to
  provide future extensibility.




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



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

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard. This is appropriate for a protocol change to HTTP. This is indicated on the document header.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

This document defines a new mechanism for communicating per-stream priorities in HTTP/2 and HTTP/3. Priority here communicates a level of urgency and information about if the data can be loaded incrementally, and can be communicated at the start of a request and updated later. This mechanism can be used instead of the unsuccessful priority mechanism originally defined in HTTP/2.

Working Group Summary:

This work item came to HTTPbis as a requirement for HTTP/3 (developed in QUIC), which on its own didn't define any priorities. The working group ran a design team for the topic early on, and has seen good engagement in development of the solution.

Document Quality:

There are a few implementations of the protocol in HTTP/3 to validate the effectiveness of the protocol, and implementations in general do intend to deploy this solution going forward (favored over the previous priority scheme). The document is well-structured and clear, and received extensive review from the WG.

Personnel:

Tommy Pauly is the Document Shepherd.
Francesca Palombini is the Responsible Area Director.

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

I reviewed the document (filed a couple editorial nits), but found it well-written.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

No concerns.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

No such review needed.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

No specific concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

Authors have confirmed that there is no IPR known or disclosed.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

No disclosures.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

The WG consensus is strong, and represents review from many individuals in the group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise 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 appeals or discontent expressed.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

The Nits tool generated this, but I don't see it as relevant:

  -- Found something which looks like a code comment -- if you have code
    sections in the document, please surround them with '' and
    '' lines.

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

No formal review required.

(13) Have all references within this document been identified as either normative or informative?

Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

No. All normative references to documents not yet published are on track.

(15) Are there downward normative references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

No downward normative references.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

This document does not change any status of existing RFCs. Note that this does not update the HTTP/2 RFC. HTTP/2 is going through its own bis document (draft-ietf-httpbis-http2bis) that references this work.

(17) 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 protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).

The IANA sections registered several HTTP items (fields and frame types), and creates a new registry for priority parameters. The information about the registry is in the body of the document and referenced from the IANA Considerations.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

Expert review is specified for the new HTTP Priority Parameters Registry. These experts should be assigned by the HTTPbis WG.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.

HTTP fields are using structured fields, which define a standard ABNF. Nothing else applicable.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) 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 RFC8342?

No YANG module.

As required by RFC 4858, this is the current template for the Document
Shepherd Write-Up. Changes are expected over time.

This version is dated 1 November 2019.

(1) What type of RFC is being requested (BCP, Proposed Standard, Internet Standard, Informational, Experimental, or Historic)? Why is this the proper type of RFC? Is this type of RFC indicated in the title page header?

Proposed Standard. This is appropriate for a protocol change to HTTP. This is indicated on the document header.

(2) The IESG approval announcement includes a Document Announcement Write-Up. Please provide such a Document Announcement Write-Up. Recent examples can be found in the "Action" announcements for approved documents. The approval announcement contains the following sections:

Technical Summary:

This document defines a new mechanism for communicating per-stream priorities in HTTP/2 and HTTP/3. Priority here communicates a level of urgency and information about if the data can be loaded incrementally, and can be communicated at the start of a request and updated later. This mechanism can be used instead of the unsuccessful priority mechanism originally defined in HTTP/2.

Working Group Summary:

This work item came to HTTPbis as a requirement for HTTP/3 (developed in QUIC), which on its own didn't define any priorities. The working group ran a design team for the topic early on, and has seen good engagement in development of the solution.

Document Quality:

There are a few implementations of the protocol in HTTP/3 to validate the effectiveness of the protocol, and implementations in general do intend to deploy this solution going forward (favored over the previous priority scheme). The document is well-structured and clear, and received extensive review from the WG.

Personnel:

Tommy Pauly is the Document Shepherd.
Francesca Palombini is the Responsible Area Director.

(3) Briefly describe the review of this document that was performed by the Document Shepherd. If this version of the document is not ready for publication, please explain why the document is being forwarded to the IESG.

I reviewed the document (filed a couple editorial nits), but found it well-written.

(4) Does the document Shepherd have any concerns about the depth or breadth of the reviews that have been performed?

No concerns.

(5) Do portions of the document need review from a particular or from broader perspective, e.g., security, operational complexity, AAA, DNS, DHCP, XML, or internationalization? If so, describe the review that took place.

No such review needed.

(6) Describe any specific concerns or issues that the Document Shepherd has with this document that the Responsible Area Director and/or the IESG should be aware of? For example, perhaps he or she is uncomfortable with certain parts of the document, or has concerns whether there really is a need for it. In any event, if the WG has discussed those issues and has indicated that it still wishes to advance the document, detail those concerns here.

No specific concerns.

(7) Has each author confirmed that any and all appropriate IPR disclosures required for full conformance with the provisions of BCP 78 and BCP 79 have already been filed. If not, explain why?

Authors have confirmed that there is no IPR known or disclosed.

(8) Has an IPR disclosure been filed that references this document? If so, summarize any WG discussion and conclusion regarding the IPR disclosures.

No disclosures.

(9) How solid is the WG consensus behind this document? Does it represent the strong concurrence of a few individuals, with others being silent, or does the WG as a whole understand and agree with it?

The WG consensus is strong, and represents review from many individuals in the group.

(10) Has anyone threatened an appeal or otherwise indicated extreme discontent? If so, please summarise 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 appeals or discontent expressed.

(11) Identify any ID nits the Document Shepherd has found in this document. (See http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

The Nits tool generated this, but I don't see it as relevant:

  -- Found something which looks like a code comment -- if you have code
    sections in the document, please surround them with '' and
    '' lines.

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

No formal review required.

(13) Have all references within this document been identified as either normative or informative?

Yes

(14) Are there normative references to documents that are not ready for advancement or are otherwise in an unclear state? If such normative references exist, what is the plan for their completion?

No. All normative references to documents not yet published are on track.

(15) Are there downward normative references (see RFC 3967)? If so, list these downward references to support the Area Director in the Last Call procedure.

No downward normative references.

(16) Will publication of this document change the status of any existing RFCs? Are those RFCs listed on the title page header, listed in the abstract, and discussed in the introduction? If the RFCs are not listed in the Abstract and Introduction, explain why, and point to the part of the document where the relationship of this document to the other RFCs is discussed. If this information is not in the document, explain why the WG considers it unnecessary.

This document does not change any status of existing RFCs. Note that this does not update the HTTP/2 RFC. HTTP/2 is going through its own bis document (draft-ietf-httpbis-http2bis) that references this work.

(17) 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 protocol extensions that the document makes are associated with the appropriate reservations in IANA registries. Confirm that any referenced IANA registries have been clearly identified. Confirm that newly created IANA registries include a detailed specification of the initial contents for the registry, that allocations procedures for future registrations are defined, and a reasonable name for the new registry has been suggested (see RFC 8126).

The IANA sections registered several HTTP items (fields and frame types), and creates a new registry for priority parameters. The information about the registry is in the body of the document and referenced from the IANA Considerations.

(18) List any new IANA registries that require Expert Review for future allocations. Provide any public guidance that the IESG would find useful in selecting the IANA Experts for these new registries.

Expert review is specified for the new HTTP Priority Parameters Registry. These experts should be assigned by the HTTPbis WG.

(19) Describe reviews and automated checks performed by the Document Shepherd to validate sections of the document written in a formal language, such as XML code, BNF rules, MIB definitions, YANG modules, etc.

HTTP fields are using structured fields, which define a standard ABNF. Nothing else applicable.

(20) If the document contains a YANG module, has the module been checked with any of the recommended validation tools (https://trac.ietf.org/trac/ops/wiki/yang-review-tools) 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 RFC8342?

No YANG module.