Deterministic Networking (DetNet) Data Plane: MPLS over IEEE 802.1 Time-Sensitive Networking (TSN)
draft-ietf-detnet-mpls-over-tsn-07

[Ballot comment]
Thank you for the work put into this document.

Please find below some blocking DISCUSS points, some non-blocking COMMENT points (but replies would be appreciated), and some nits.

Special thanks to Tim for his INT directorate review as well to Balázs for his answer:
- INT directorate: Tim Chown https://datatracker.ietf.org/doc/review-ietf-detnet-mpls-over-tsn-05-intdir-telechat-chown-2021-02-14/

I am trusting Tim's review for my ballot and I am sure that they helped to improve the document,

Regards,

-éric

[Ballot comment]
Roman's comment is a good one.

Section 3

  and process d-CWs, S-Labels and F-labels as needed.  MPLS DetNet
  nodes and transit nodes include DetNet forwarding sub-layer
  functions, support for notably explicit routes, and resources
  allocation to eliminate (or reduce) congestion loss and jitter.

Akin to my remarks on draft-ietf-detnet-tsn-vpn-over-mpls, I'd suggest
"notably support for explicit routes, and resource allocation to
eliminate (or reduce) congestion loss and jitter".

Section 4.2

  A TSN-aware MPLS (DetNet) node implementation must support the
  Sequencing function and the Sequence encode/decode function as
  defined in Clause 7.4 and 7.6 of IEEE 802.1CB [IEEE8021CB] if FRER is
  used inside the TSN sub-network.
  [...]
  A TSN-aware MPLS (DetNet) node implementation must support the Stream
  splitting function and the Individual recovery function as defined in
  Clause 7.7 and 7.5 of IEEE 802.1CB [IEEE8021CB] when the node is a
  replication or elimination point for FRER.

(nit) I suggest phrasing these as "in order for FRIR to be used inside
the TSN sub-network" and "in order for that node to be a replication or
elimination point for FRER".  The current phrasing implies some
surprising causality, as if changing the network's configuration
spontaneously imposes a requirement on the node.

Section 4.4

  Implementations of this document shall use management and control
  information to map a DetNet flow to a TSN Stream.  N:1 mapping
  (aggregating DetNet flows in a single TSN Stream) shall be supported.

I note that in draft-ietf-detnet-tsn-vpn-over-mpls this was a normative
"SHALL be supported" (which was itself the strongest criterion I could
find for that document being standards-track).  Is there a simple
description for what's different between these documents?

Section 5

  requirements.  Note that, as the TSN sub-network is just a portion of
  the end2end DetNet path (i.e., single hop from MPLS perspective),

nit: please write out "end-to-end".

  In some case it may be challenging to determine some TSN Stream
  related information.  [...]

nit: "In some cases".

[Ballot comment]
This document is "MPLS over IEEE 802.1 Time-Sensitive Networking".  Also on this telechat: "IEEE 802.1 Time Sensitive Networking over MPLS".  I wonder if one is just the inverse of the other.

I concur with Alvaro's statement about the IEEE references being normative.

In Section 2.2, "CW" is defined, but the term used in the document is actually "d-CW".  The terms "DF", "LSR", "PE", "S-PE", and "T-PE" are defined but not used anywhere.

In Section 4, I can't parse this sentence: "All these functions have to identify flows those require TSN treatment (i.e., applying TSN functions during forwarding)."

Section 6 says: "Therefore, it is important that the interface between DetNet nodes and TSN sub-network are subject to authorization, authentication, and encryption."  Would references to documents describing those specific TSN capabilities be useful here?  I'm not sure if those are covered by the referenced TSN documents.

[Ballot comment]
I agree with Alvaro's ballot points. I think IEEEP8021CBcv should also be a normative reference.

= Abstract =

"Whenever this document makes
  requirements statements or recommendations, these are taken from
  normative text in the referenced RFCs."
 
I found the use of "requirements statements" a little misleading since this document contains no normative language.

= Section 4 =

"The Time-Sensitive Networking (TSN) Task Group of the IEEE 802.1
  Working Group have defined (and are defining) a number of amendments
  to IEEE 802.1Q [IEEE8021Q] that provide zero congestion loss and
  bounded latency in bridged networks."

Since this is going into an immutable RFC, starting with "At the time of this writing" or some such would be helpful.

[Ballot comment]
Thank you to Yoav Nir for the SECDIR review.

As noted in the abstract, “[t]his document does not define new procedures or processes.”  Since Sections 1 – 5 appears to rely heavily on TSN references, I was surprised that the Security Considerations did not follow the same pattern.  I would have expected pointers into the underlying IEEE TSN specifications on security considerations.  The text appears to be generic, and beyond a single sentence, identical to draft-ietf-detnet-ip-over-tsn.

[Ballot comment]
The following references should be Normative: I-D.ietf-detnet-security, IEEE8021Q, and RFC8655.

These references describe TSN, an understanding which is required, the architecture, and security considerations for DetNet -- note that other data plane documents use them normatively as well.


====

For the record (no need to reply)

I'm having a hard time convincing myself that this document has archival value as an RFC, given that the procedures are already specified in the IEEE documents.  I had a similar concern (related to the contributions made in the document) about draft-ietf-detnet-ip-over-mpls (which is on the Standards Track).  As with the MPLS document, I am making this a non-blocking comment and not opposing the publication.

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

The IANA Functions Operator has reviewed draft-ietf-detnet-mpls-over-tsn-05, 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.

Thank you,

Sabrina Tanamal
Senior IANA Services Specialist

The following Last Call announcement was sent out (ends 2021-02-05):

From: The IESG
To: IETF-Announce
CC: Lou Berger , db3546@att.com, detnet-chairs@ietf.org, detnet@ietf.org, draft-ietf-detnet-mpls-over-tsn@ietf.org, lberger@labn.net
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (DetNet Data Plane: MPLS over IEEE 802.1 Time Sensitive Networking (TSN)) to Informational RFC


The IESG has received a request from the Deterministic Networking WG (detnet)
to consider the following document: - 'DetNet Data Plane: MPLS over IEEE
802.1 Time Sensitive Networking
  (TSN)'
  as Informational RFC

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 2021-02-05. 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 specifies the Deterministic Networking MPLS data plane
  when operating over a TSN sub-network.  This document does not define
  new procedures or processes.  Whenever this document makes
  requirements statements or recommendations, these are taken from
  normative text in the referenced RFCs.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-detnet-mpls-over-tsn/



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?

This is an Informational RFC that describes how other standards
documents can be combined.  No new mechanisms or recommendations are
defined.

> 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.


  This document describes how the Deterministic Networking MPLS data
  plane can operate over a TSN sub-network data plane.  This document
  does not define new procedures or processes. 


> 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?

Nothing notable.

> 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, YANG 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?

The document is an Informational document. Early implementations of IP
over DetNet were demonstrated by WG members.

> Personnel:

> Who is the Document Shepherd?
Lou Berger

> Who is the Responsible Area Director?
Deborah Brungard

> (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.

The Shepherd reviewed this document as it progressed through the WG as
well as part of Last Call.  All significant comments have been resolved.

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

No

> (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.

> (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 concerns, assuming published as Informational.

> (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?

Yes, see
https://mailarchive.ietf.org/arch/msg/detnet/gJj-BUPESxSEcAlksqhXMaxhBqg/

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

No IPR has been disclosed.

> (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?

I think the document has good support from a narrow set of WG participants.

> (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

> (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.

No.

> (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.

Idnits issues have been fixed.

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

N/A.

> (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.

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

No.

> (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.

No, N/A.

> (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).

No requests are made in the document.

> (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.

None.

> (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.

N/A

> (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?

There are no yang models.

> 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?

This is an Informational RFC that describes how other standards
documents can be combined.  No new mechanisms or recommendations are
defined.

> 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.


  This document describes how the Deterministic Networking MPLS data
  plane can operate over a TSN sub-network data plane.  This document
  does not define new procedures or processes. 


> 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?

Nothing notable.

> 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, YANG 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?

The document is an Informational document. Early implementations of IP
over DetNet were demonstrated by WG members.

> Personnel:

> Who is the Document Shepherd?
Lou Berger

> Who is the Responsible Area Director?
Deborah Brungard

> (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.

The Shepherd reviewed this document as it progressed through the WG as
well as part of Last Call.  All significant comments have been resolved.

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

No

> (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.

> (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 concerns, assuming published as Informational.

> (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?

Yes, see
https://mailarchive.ietf.org/arch/msg/detnet/gJj-BUPESxSEcAlksqhXMaxhBqg/

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

No IPR has been disclosed.

> (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?

I think the document has good support from a narrow set of WG participants.

> (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

> (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.

No.

> (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.

Idnits issues have been fixed.

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

N/A.

> (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.

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

No.

> (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.

No, N/A.

> (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).

No requests are made in the document.

> (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.

None.

> (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.

N/A

> (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?

There are no yang models.