Static Context Header Compression (SCHC) Compound Acknowledgement (ACK)
draft-ietf-lpwan-schc-compound-ack-17

[Ballot comment]
There is probably also some cosmetic cleanup of the YANG module that might help (although the RFC editor will normally also check this).

I've run it through "pyang -f yang --yang-line-length 69 ietf-lpwan-schc-compound-ack@2022-12-02.yang > ietf-lpwan-schc-compound-ack@2023-03-16.yang" to fix the spacing and also manually added some blank lines to the top level module description.  I'll attach this as an email response to my ballot position for you to use if you wish.

Thanks,
Rob

[Ballot comment]
Some small comments:

In section 8.4.3. ACK-on-Error Mode, there are a bunch of MUST requirements. If one of these fails, what will happen? Is there a chance of causing an ACK-on-Error reply, which then might cause an ACK-on-Error storm between two nodes?

There is a similar issue with lots of MUST clauses further on. Perhaps it would be useful to have add a sentence somewhere reminding implementers that error handling is defined in https://www.rfc-editor.org/rfc/rfc8724.html#section-7.2  (which mostly states "MUST drop packet", so avoids error storms, answering my own comment above :)

[Ballot comment]
Thank you to the authors for writing this, and also to Tianran Zhou for the OpsDir review (https://datatracker.ietf.org/doc/review-ietf-lpwan-schc-compound-ack-12-opsdir-lc-zhou-2023-03-02/)

I'm not completely sure that the added text ("The receiver can suspect if the sender does not support the SCHC Compound ACK, if the sender does not resend any tiles from windows that are not the first one in the SCHC Compound ACK and more ACKs are needed.") fully addresses the OpsDir concern - yes, it can suspect this, but it seems like it would be helpful to provide a suggestion as to what a receiver should do if it suspect this.... I'm leaving this as NoObj because I think that a: the authors will add something and if not, b: implementors will be able to figure it out.

[Ballot comment]
Thank you to Brian Weis for the SECDIR review.

Per id-nits:
  -- The draft header indicates that this document updates RFC8724, but the
    abstract doesn't seem to directly say this.  It does mention RFC8724
    though, so this could be OK.

[Ballot comment]
Thanks for this document, in particular I appreciated the care you took to accommodate non-experts in the Introduction. I have a few minor comments you may want to consider.

1. In Section 3.2 you write,

“The following Section 8.4.3 (and its subsections) replaces the complete sections 8.4.2 (and its subsections) of RFC 8724.”

I assume this must be a typo, and what you actually mean is that it replaces 8.4.3, right?

2. In 8.4.3 you have,

"if the last tile is carried in a Regular SCHC Fragment or an All-1 SCHC Fragment Section 8.4.3.1), and"

You seem to have lost the "(see " that was present in the original text, i.e. I think what it should read is,

"if the last tile is carried in a Regular SCHC Fragment or an All-1 SCHC Fragment Section (see 8.4.3.1), and"

3. In 8.4.3.2 you write,

"if the receiver knows of any windows with missing tiles for the packet being reassembled (and if network conditions are known to be conducive), it MAY return a SCHC Compound ACK for the missing tiles, starting from the lowest-numbered window."

I leave it to your discretion and that of others who know this field better than I do, however "(and if network conditions are known to be conducive)" seems pretty vague on the face of it -- maybe an implementor who is skilled in the field would say "ah yes, I know exactly what to do with this", but to me it's uninformative. If it's possible to make this more descriptive and ideally more prescriptive, that would be great.

[Ballot comment]
Two quick notes:
- feel free to defer or ask me to postpone to April telechat (but 16th of March telechat is 'light')
- more than 5 authors, but, as indicated in the shepherd write-up, there is a Ph.D. and the associated academia

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

The IANA Functions Operator has reviewed draft-ietf-lpwan-schc-compound-ack-12, 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 2023-03-09):

From: The IESG
To: IETF-Announce
CC: a@ackl.io, draft-ietf-lpwan-schc-compound-ack@ietf.org, evyncke@cisco.com, lp-wan@ietf.org, lpwan-chairs@ietf.org, pthubert@cisco.com
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (SCHC Compound ACK) to Proposed Standard


The IESG has received a request from the IPv6 over Low Power Wide-Area
Networks WG (lpwan) to consider the following document: - 'SCHC Compound ACK'
  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 2023-03-09. 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


  The present document updates the SCHC (Static Context Header
  Compression and fragmentation) protocol RFC8724.  It defines a SCHC
  Compound ACK message format and procedure, which are intended to
  reduce the number of response transmissions (i.e., SCHC ACKs) in the
  ACK-on-Error mode, by accumulating bitmaps of several windows in a
  single SCHC message (i.e., the SCHC Compound ACK).

  Both message format and procedure are generic, so they can be used,
  for instance, by any of the four Low Power Wide Area Networks
  (LPWANs) technologies defined in RFC8376, being Sigfox, LoRaWAN, NB-
  IoT and IEEE 802.15.4w.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-lpwan-schc-compound-ack/



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

This is the publication request and document shepherd write up for:
https://datatracker.ietf.org/doc/draft-ietf-lpwan-schc-compound-ack/10/

# 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?

There was a broad consensus in the WG about the document. All remarks and potential issues were treated with respect, discussed openly and addressed. 

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

No controversies, no rough points.


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 recommends) or elsewhere
(where)?

There is an implementation of the Compound ACK as part of the The SCHC over Sigfox Project - an open source implementation of the SCHC over Sigfox draft - which can be found at the following addresses:
https://github.com/schc-over-sigfox
https://github.com/saguilarDevel/schc-sigfox

There is an internal Acklio 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.

No, the Compound Ack extension of the Ack-On-Err fragmentation mode is specifically designed and in relation to RFC8724 of the LPWAN WG.

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.

The document includes a straightforward YANG model, but has not been reviewed by a YANG doctor.

A YANG doctor review was requested and the results will be part of a next review of the Shepherd Writeup.


7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation 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 RFC 8342?

The YANG model compiles correctly with no warnings.


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.

No such formal language verifications are necessary.


# 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, the document is clearly written and ready to be handed off.


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

No issues from the list are relevant to the document.


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

The document is in the Standards Track. This is the proper type, as the document extends RFC8724, which is also Standards Track. The correct attribute is stated on the Datatracker.


12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? 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.

All authors have replied. No IPR on this document.



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.

All authors have confirmed their willingness to be listed as such.
There are 6 authors, but many come from Academia, some of which more recent authors.


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

No nits.


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

No, there are two sections with appropriate document referencing - Normative and Informative.

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 and BCP
97) that are not already listed in the DOWNREF registry? 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?

No such reference.

19) Will publication of this document change the status of any existing RFCs?

No, it extends the RFC8724.

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).

The document has no IANA actions.

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.

The document has no IANA actions.

This is the publication request and document shepherd write up for:
https://datatracker.ietf.org/doc/draft-ietf-lpwan-schc-compound-ack/10/

# 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?

There was a broad consensus in the WG about the document. All remarks and potential issues were treated with respect, discussed openly and addressed. 

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

No controversies, no rough points.


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 recommends) or elsewhere
(where)?

There are existing implementations.


# 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.

No, the Compound Ack extension of the Ack-On-Err fragmentation mode is specifically designed and in relation to RFC8724 of the LPWAN WG.

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.

The document includes a straightforward YANG model, but has not been reviewed by a YANG doctor.

7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation 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 RFC 8342?

The YANG model compiles correctly with no warnings.


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.

No such formal language verifications are necessary.


# 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, the document is clearly written and ready to be handed off.


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

No issues from the list are relevant to the document.


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

The document is in the Standards Track. This is the proper type, as the document extends RFC8724, which is also Standards Track. The correct attribute is stated on the Datatracker.


12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? 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.

All authors have replied. No IPR on this document.



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.

All authors have confirmed their willingness to be listed as such.
There are 6 authors, but many come from Academia, some of which more recent authors.


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

No nits.


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

No, there are two sections with appropriate document referencing - Normative and Informative.

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 and BCP
97) that are not already listed in the DOWNREF registry? 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?

No such reference.

19) Will publication of this document change the status of any existing RFCs?

No, it extends the RFC8724.

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).

The document has no IANA actions.

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.

The document has no IANA actions.

This is the publication request and document shepherd write up for:
https://datatracker.ietf.org/doc/draft-ietf-lpwan-schc-compound-ack/10/

# 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?

There was a broad consensus in the WG about the document. All remarks and potential issues were treated with respect, discussed openly and addressed. 

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

No controversies, no rough points.


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 recommends) or elsewhere
(where)?

There are existing implementations.


# 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.

No, the Compound Ack extension of the Ack-On-Err fragmentation mode is specifically designed and in relation to RFC8724 of the LPWAN WG.

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.

The document includes a straightforward YANG model, but has not been reviewed by a YANG doctor.

7) If the document contains a YANG module, has the final version of the module
been checked with any of the recommended validation 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 RFC 8342?

The YANG model compiles correctly with no warnings.


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.

No such formal language verifications are necessary.


# 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, the document is clearly written and ready to be handed off.


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

No issues from the list are relevant to the document.


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

The document is in the Standards Track. This is the proper type, as the document extends RFC8724, which is also Standards Track. The correct attribute is stated on the Datatracker.


12) Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in BCP 79? 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.

All authors have replied. No IPR on this document.



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.

All authors have confirmed their willingness to be listed as such.
There are 6 authors, but many come from Academia, some of which more recent authors.


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

No nits.


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

No, there are two sections with appropriate document referencing - Normative and Informative.

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 and BCP
97) that are not already listed in the DOWNREF registry? 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?

No such reference.

19) Will publication of this document change the status of any existing RFCs?

No, it extends the RFC8724.

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).

The document has no IANA actions.

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.

The document has no IANA actions.

Request for posting confirmation emailed to previous authors: Carles Gomez , Diego Torre , Juan Zuniga , Laurent Toutain , Sandra Cespedes , Sergio Aguilar , lpwan-chairs@ietf.org