A Framework for Automating Service and Network Management with YANG
draft-ietf-opsawg-model-automation-framework-10

[Ballot comment]
Sorry that there are so many editorial nits mixed in with actual
content-ful comments.  I think they are all marked as such, at least.

Section 1

  o  The lack of standard data input/output (i.e., data model) raises
      many challenges in system integration and often results in manual
      configuration tasks.

(nit) I feel like this would read better with "interfaces" after
"input/output".

  o  Ease data inheritance and reusability among the various
      architecture layers promoting thus a network-wise provisioning
      instead of device-specific configuration.

nit: this looks better with "thus" and "promoting" swapped.

  o  Dynamically fed a decision-making process (e.g., Controllers,

nit: s/fed/feed/.

      Orchestrators) with notifications that will trigger appropriate
      actions allowing thus to continuously adjust a network (and thus
      involved resources) to comply the intended service to deliver.

nit: the wording here also feels a bit unusual.  Perhaps:

%    o  Dynamically fedd a decision-making process (e.g., Controllers,
%      Orchestrators) with notifications that will trigger appropriate
%      actions, allowing them to continuously adjust a network (and
%      thus, the involved resources) to deliver service that conforms
%      to the intended parameters.

Section 2.2

"AP" should probably be in the list as well.
We don't seem to define "PM" as such anywhere (though "Performance
Monitoring" appears four or five times), but do use it in Appendix A.4.4.

Section 3.1

  Each level maintains a view of the supported YANG modules provided by
  low-levels (see for example, Appendix A).

nit(?): "lower levels"

Section 3.2

  Distributed Denial-of-Service (DDoS) attacks [RFC8783].  The service
  filtering request modelled using [RFC8783] will be translated into
  device-specific filtering (e.g., ACLs defined in [RFC8519]) that to
  fulfil the service request.

nit: s/that to/that/

Section 3.3

  Note that it is important to correlate telemetry data with
  configuration data to be used for closed loops at the different
  stages of service delivery, from resource allocation to service
  operation, in particular.

Is "closed loops" a well-known term in this space?

Section 4.1.2

  service requirements in the service request can be met (i.e., whether
  there is sufficient resources that can be allocated with the
  requested guarantees).

nit: s/is/are/

  In addition, a customer may require to change the underlying network
  infrastructure to adapt to new customer's needs and service
  requirements.  This service modification can be issued following the
  same Service Model used by the service request.

I'm not sure I understand what "underlying network infrastructure" means
here -- are there supposed to come into being new routers because the
customer issues a request in the Service Model?

Section 4.1.3

  Performance measurement telemetry model can tie with Service or
  Network Models to monitor network performance or Service Level
  Agreement.

nit: missing article (e.g., "The performance measurement telemetry
model").

Section 4.1.4

  Service optimization is a technique that gets the configuration of
  the network updated due to network changes, incidents mitigation, or

nit: s/incidents/incident/

Section 4.2.1

  configuration models for network elements; the configuration
  information includes:
  [...]
  o  Security

I think we need some more details than just "Security".  Are these
security protocols?  Security properties?  Physical security?  What is
in or out of scope for being covered by any indicated security
mechanisms?

Section 4.2.2

  For example, a customer creates an interface "eth-0/0/0" but the
  interface does not physically exist at this point, then configuration
  data appears in the  status but does not appear in
    datastore.

nit: I think this reads better as "if a customer creates" (added "if").

Section 4.2.3

  When a configuration is in effect in a device,

nit: "the ".

Section 4.3

  Another example is to map service parameters in the L3SM into Traffic
  Engineered (TE) tunnel parameter (e.g., Tunnel ID) in TE model and

nit: "parameters" plural.

Section 5.1

  L3NM inherits some of data elements from the L3SM.  Nevertheless, the
  L3NM does not expose some information to the above layer such as the
  capabilities of an underlying network (which can be used to drive
  service order handling) or notifications (to notify subscribers about
  specific events or degradations as per agreed SLAs).  Some of this

I'm having a bit of trouble putting this bit together -- specifically
the "not" in "does not expose".  The rest of the text makes it sound
like having the Service layer know some capabilities of the underlying
network, or receive notifications from network-layer events, will be
useful to the Orchestrator.  But the text as-is seems to say that such
information will not be provided to the Service layer.

Section 5.2

  3.  The customer exchanges with the Orchestrator the connectivity
      matrix on the abstract node and explicit paths using the TE

nit: I think this is still the "abstract node topology".

  4.  The telemetry model which augments the VN model and corresponding
      TE tunnel model can be used to subscribe to performance
      measurement data and notify all the parameter changes and network

nit: "notify" takes an object that is the entity receiving the
notifications; the current wording as literally written says that "all
the parameter changes and network performance changes" will receive
notifications; I believe that the intent is that notifications about
such changes are delivered to something (the Orchestrator?), so we
should instead say "provide notifications about" or specify the actual
object of "notify".

Section 5.3

      actions are defined and correlated with network events (e.g.,
      allow the NETCONF server to send updates only when the value
      exceeds a certain threshold for the first time, but not again
      until the threshold is cleared), which constitute an

It's perhaps a little risky to mention such threshold-based behavior
without mentioning hysteresis as well.

      the server via YANG Push subscription [RFC8641], monitors state
      parameters, and takes simple and instant actions when associated
      event condition on state parameters is met.  ECA notifications

nit: "an" or "the" associated event condition.

Section 6

I agree with the secdir reviewer that it's worth repeating the
disclaimer that customer/provider interfaces (and thus, the security
considerations thereof) are out of scope for this document.

When the service configuration incluedes "security" parameters (see my
comment on §4.2.1), it is important to include the relevant information
in the monitoring/assurance pipelines so that the correct functioning of
the security mechanisms is tracked.

  In order to prevent leaking sensitive information, special care
  should be considered when translating between the various layers in
  Section 4 or when aggregating data retrieved from various sources.

It's also important to perform the necessary authentication and
authorization checks (more specifically than just "special care") for
operations that cross abstraction-layer boundaries.  The "confused
deputy problem" may be relevant for some of these cases, and is an
important topic to mention as well.

Section 6.1

  providers.  The characterization of a service disruption (including,
  mean time between failures, mean time to repair), the escalation
  procedure, and penalties are usually documented in contractual
  agreements (e.g., Section 2.1 of [RFC4176]).  Misbehaving peer

nit: pedantically, this is saying that Section 2.1 of RFC 4176 is an
example of a contracutal agreement; we may want to say "e.g., as
described in Section 2.1 of [RFC4176]" instead.

Section 6.2

  o  Some Service Models may include a traffic isolation clause,
      appropriate technology-specific actions must be enforced at the
      underlying network (and thus involved network devices) to avoid
      that such traffic is accessible to non-authorized parties.

It may be worth mentioning the potential misconception that a "virtual
private network" always provides privacy against an attacker able to tap
the network link(s); only some VPN technologies (can be configured to)
do so.  In some sense, whether such wire-level encryption is in use
could be an aspect exposed at the service model layer.

Section A.3

  o  Network Topologies Model: [RFC8345] defines a base model for
      network topology and inventories.  Network topology data include
      link resource, node resource, and terminate-point resources.

nit: probably all three instances should be "resources" plural?

Section A.4

  Network Element models (Figure 10) are used to describe how a service
  can be implemented by activating and tweaking a set of functions
  (enabled in one or multiple devices, or hosted in cloud
  infrastructures) that are involved in the service delivery.

I don't really see how Figure 10 helps demonstrate *how* "a service can
be implemented by activating and tweaking a set of functions"; it seems
to just be a listing/categorization of things that have YANG models.

[Ballot comment]
[[ nits ]]

[ section 1 ]

* "processing of customer's" -> "processing of customer", perhaps

* The colon-delimited sentence ending the paragraph doesn't seem to imply
  that list is what should logically follow.  I think the sentence aims to
  imply that in-house and silo nature of existing work has lead the some
  challenges, including the ones listed.  I think a slight reword might
  fix this up pretty easily.

* "between a NETCONF/RESTCONF clients and servers" ->
  "between NETCONF/RESTCONF clients and servers"

* "YANG is transport independent" -> "YANG is a transport-independent"

* "model composing" -> "model composition" perhaps?

* "out of the scope" -> "out of scope"

[ section 3.2 ]

* "that to fulfil the service request"?
  perhaps "that fulfill the service request"?

[ section 3.4 ]

* "to support newly added module", suggest either:
  "to support newly added modules" or "to support a newly added module"
  (probably the former, given subsequent "and features")

[ section 4.2.4 ]

* "or network resources be mis-allocated" ->
  "or network resources might be mis-allocated"

[Ballot comment]
Thank you for responding to the SECDIR Review (and thank you to Christian Huitema for providing the review)

Focusing primarily on Section 3 and 4 (and ignoring the examples in Section 5), I didn’t find much guidance on using YANG as was suggested by the introductory materials.

** Section 3.1.  Figure 2 notes “full guarantees class” and “delay guarantees class” which seems to speak to a particular class of traffic, but I didn’t follow what these were.

** Section 6.  Per “ The YANG modules cited in this document define schema for data that are designed to be accessed via network management protocols such as  NETCONF [RFC6241] or RESTCONF [RFC8040]”, this seems to conflict with Section 1 which reminds us that “any of the YANG modules listed in this document are used to exchange data between a NETCONF/RESTCONF clients and servers [RFC6241][RFC8040].  Nevertheless, YANG is transport independent data modeling language.  It can thus be used independently of NETCONF/RESTOCNF.”  To be clear, the behavior described in the latter is not part of this architecture?

** Section 6.  The following architectural assumptions seem to conflict:

-- Section 3.1, “All these elements (i.e., Orchestrator(s), Controller(s), device(s)) are under the responsibility of the same operator.

-- Section 6.1. “A provider may rely on services offered by other providers to build composite services.”

Is the assumption that “under the responsibility of” to include contractual arrangement with the service provider?

** Section 6.  Per “In order to prevent leaking sensitive information, special care should be considered when translating between the various layers in Section 4 or when aggregating data retrieved from various sources.”, agreed.  However, as Section 6.1. suggests that services from other providers may also be used, this caution should extend to be both in the layer and inter and intra layers.

** Editorial Nits
Section 1.  Editorial.  s/Dynamically fed/Dynamically feed/

Section 3.1.  Typo. s/Connectivty/Connectivity/

Section 3.3. Typo. s/Fullfillment/Fulfillment/

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

Please find below a couple of non-blocking COMMENT points and nits. I hope that this helps to improve the document,

Regards,

-éric

== COMMENTS ==

A generic comment: it hurts my eyes to see several occurrences of "NAT" as a service in an IETF document in 2020...

Should there be a reference to draft-claise-opsawg-service-assurance-architecture (albeit not yet an adopted document) ?

There are a lot of detailed service creations with a good decomposition of all the required steps; but, little is written on the importance of YANG models (as opposed to any standard data exchange), so, the current title seems a little misleading.


-- Abstract --
To be honest, I fail to understand why data models can be used to 'derive' configuration information. Did the authors mean 'describe' or 'specify' ?

Later "This document describes an architecture" while the title of this document if "framework" ? Slight semantic difference ;-)

And later "accommodate modules that", is it 'YANG modules' or 'data models' ?


-- Section 4 --
The complex figure 4 would benefit from some textual introduction referring to the subsections. Also, the meaning of the arrow would gain if specified. E.g., why "Service Diagnosis" does not have a loop back to optimization or assurance ?

-- Section 4.2.2 --
If not mistaken, this is the first appearance of the notation "". Do the angle brackets have a specific meaning?

-- Section 4.2.3 --
Suggestion to use the figure 4 wording as the title esp. since the wording of MDT is not really used in the sub-section.

-- Section 6 --
Is it required/useful to have the 'standard YANG security considerations" in this document that does not contain any YANG module?

-- Section 10.1 --
Most of the references should probably be informational only.


== NITS ==

Generic nit, I found the use of capitalized "Service Model" or "Network Models" a little disturbing.

-- Section 1 --
"how different layer YANG data models" is rather difficult to parse, suggest to rephrase it.

-- Section 4.4 --
Is it "service decomposing" or "service decomposition" ?

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

The IANA Functions Operator has reviewed draft-ietf-opsawg-model-automation-framework-06, 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 2020-10-08):

From: The IESG
To: IETF-Announce
CC: opsawg-chairs@ietf.org, draft-ietf-opsawg-model-automation-framework@ietf.org, Adrian Farrel , opsawg@ietf.org, rwilton@cisco.com, adrian@olddog.co.uk
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (A Framework for Automating Service and Network Management with YANG) to Informational RFC


The IESG has received a request from the Operations and Management Area
Working Group WG (opsawg) to consider the following document: - 'A Framework
for Automating Service and Network Management with YANG'
  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 2020-10-08. 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


  Data models provide a programmatic approach to represent services and
  networks.  Concretely, they can be used to derive configuration
  information for network and service components, and state information
  that will be monitored and tracked.  Data models can be used during
  the service and network management life cycle, such as service
  instantiation, provisioning, optimization, monitoring, diagnostic,
  and assurance.  Data models are also instrumental in the automation
  of network management, and they can provide closed-loop control for
  adaptive and deterministic service creation, delivery, and
  maintenance.

  This document describes an architecture for service and network
  management automation that takes advantage of YANG modeling
  technologies.  This architecture is drawn from a network operator
  perspective irrespective of the origin of a data module; it can thus
  accommodate modules that are developed outside the IETF.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-opsawg-model-automation-framework/



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

Shepherd write-up for draft-ietf-opsawg-model-automation-framework-04

> (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 document requests publication as an Informational RFC. That is
indicated on the header page.

It is appropriate for this document because it is a framework that
describes the use of data models specified in other documents. It does
not dictate any on-wire behavior, and does not specify any
interoperablity.

> (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 describes an architecture for service and network
management automation that takes advantage of YANG modeling
technologies.  This architecture is drawn from a Network Operator
perspective irrespective of the origin of a data module; it can thus
accommodate modules that are developed outside the IETF.

Data models provide a programmatic approach to represent services and
networks.  Concretely, they can be used to derive configuration
information for network and service components, and state information
that will be monitored and tracked.  Data models can be used during
the service and network management life cycle, such as service
instantiation, provisioning, optimization, monitoring, diagnostic,
and assurance.  Data models are also instrumental in the automation
of network management, and they can provide closed-loop control for
adaptive and deterministic service creation, delivery, and
maintenance.

> Working Group Summary:

This document ran eight versions before adoption into the working
group. The adoption poll included responses from fifteen people and
general support was indicated.

There was some debate about the filename at the time of adoption, and
the result was a name that better matched the purpose of the document.

The WG draft was presented at one physical meeting and at the IETF-107
virtual meeting. Points were raised and the draft updated.

WG last call attracted fewer commenters, but there were several detailed
reviews which were addressed.

There were no points of contention.

> Document Quality:

This document is not intended for implementation, but as a guideline for
building and deploying management systems. The involvement of four
network operators in the authorship indicates that the document has been
viewed carefully by those involved in deploying network management
systems.

> Personnel:

The document shepherd is Adrian Farrel
The Responsible Area Director is Rob Wilton

> (3) Briefly describe the review of this document that was performed by
>    the Document Shepherd.

I did a cursory review of this document at the time of adoption, and a
detailed review during working group last call. All of my comments have
been addressed.

I have done a subsequent review of the document to make sure it was not
broken during updates after WG last call.

This version is ready for publication.

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

No concerns.
As usual these days, it would have been nice to receive some more
reviews, but there were enough that it is reasonable to advance the
document.

> (5) Do portions of the document need review from a particular or from
>    broader perspective.

There is no use of formal language in the document and no need for
specific targeted reviews.

As previously noted, this document concerns deployment and use of
network management systems and so can benefit from additional reviews by
network operators. However, sufficient operator input has been receieved
to give confidence about the contents.

> (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?

No such 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.

All done. IPR responses can be seen at:

  Q. Wu: https://mailarchive.ietf.org/arch/msg/opsawg/zebmEbg9lOLZy9yYCPea94LIU6k/
  M. Boucadair : https://mailarchive.ietf.org/arch/msg/opsawg/MtYvDrUqjcSoPMSsTg_ZpvR0eTQ/
  D. Lopez: https://mailarchive.ietf.org/arch/msg/opsawg/zNP3w3IVZkffakWyk-pxBYuRFr8/
  C. Xie: https://mailarchive.ietf.org/arch/msg/opsawg/zyDDzrs0ZF9jBIRp1IP0CZcVBbE/
  L. Geng: https://mailarchive.ietf.org/arch/msg/opsawg/5TUtcJ22HCVPmb3TGD7QUu1rz6A/
  C. Jacquenet: https://mailarchive.ietf.org/arch/msg/opsawg/ugSjfI7ZH_dPa0WXeflDqpJJLmg/
  Luis Miguel Contreras Murillo: https://mailarchive.ietf.org/arch/msg/opsawg/n-9UACXuUvMmpCO6DDiIDqZrbVI/
  Oscar Gonzalez de Dios: https://mailarchive.ietf.org/arch/msg/opsawg/h-45h77DJiV7gkUpN5w3260hIqw/
  Weiqiang Cheng: https://mailarchive.ietf.org/arch/msg/opsawg/u3UKqjhZAn27R4J0Fm-eqAoC7Tc/
  Young Lee: https://mailarchive.ietf.org/arch/msg/opsawg/j06bIB8h0tuiJ1PRO5lSfnGOCy0/

> (8) Has an IPR disclosure been filed that references this document?

No.

> (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?

Reasonable support with no dissent.
I would say that part of the WG is not interested in the subject matter
and so had no opinion. But with a large list of authors and contributors
this catches the mood of the WG.

> (10) Has anyone threatened an appeal or otherwise indicated extreme
>      discontent?

No.

> (11) Identify any ID nits the Document Shepherd has found in this
>      document.

idnits is clean except for a number of referenced I-Ds that have moved
on to later revisions. That is picked up automatically the next time the
XML is processed.

> (12) Describe how the document meets any required formal review
>      criteria

No formal language used. No criteria to be met.

> (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?

All normative references are to published RFCs.

> (15) Are there downward normative references references (see
>      RFC 3967)?

No downrefs.

> (16) Will publication of this document change the status of any
>      existing RFCs?

No.

> (17) Describe the Document Shepherd's review of the IANA
>      considerations section.

The document makes no request for any IANA action.

An appropriate "null" IANA Considerations section is included.

> (18) List any new IANA registries that require Expert Review for
>      future allocations.

None.

> (19) Describe reviews and automated checks performed by the Document
>      Shepherd to validate sections of the document written in a formal
>      language.

No formal language is used in this document.

> (20) If the document contains a YANG module

The document does not contain a YANG module.

Shepherd write-up for draft-ietf-opsawg-model-automation-framework-04

> (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 document requests publication as an Informational RFC. That is
indicated on the header page.

It is appropriate for this document because it is a framework that
describes the use of data models specified in other documents. It does
not dictate any on-wire behavior, and does not specify any
interoperablity.

> (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 describes an architecture for service and network
management automation that takes advantage of YANG modeling
technologies.  This architecture is drawn from a Network Operator
perspective irrespective of the origin of a data module; it can thus
accommodate modules that are developed outside the IETF.

Data models provide a programmatic approach to represent services and
networks.  Concretely, they can be used to derive configuration
information for network and service components, and state information
that will be monitored and tracked.  Data models can be used during
the service and network management life cycle, such as service
instantiation, provisioning, optimization, monitoring, diagnostic,
and assurance.  Data models are also instrumental in the automation
of network management, and they can provide closed-loop control for
adaptive and deterministic service creation, delivery, and
maintenance.

> Working Group Summary:

This document ran eight versions before adoption into the working
group. The adoption poll included responses from fifteen people and
general support was indicated.

There was some debate about the filename at the time of adoption, and
the result was a name that better matched the purpose of the document.

The WG draft was presented at one physical meeting and at the IETF-107
virtual meeting. Points were raised and the draft updated.

WG last call attracted fewer commenters, but there were several detailed
reviews which were addressed.

There were no points of contention.

> Document Quality:

This document is not intended for implementation, but as a guideline for
building and deploying management systems. The involvement of four
network operators in the authorship indicates that the document has been
viewed carefully by those involved in deploying network management
systems.

> Personnel:

The document shepherd is Adrian Farrel
The Responsible Area Director is Rob Wilton

> (3) Briefly describe the review of this document that was performed by
>    the Document Shepherd.

I did a cursory review of this document at the time of adoption, and a
detailed review during working group last call. All of my comments have
been addressed.

I have done a subsequent review of the document to make sure it was not
broken during updates after WG last call.

This version is ready for publication.

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

No concerns.
As usual these days, it would have been nice to receive some more
reviews, but there were enough that it is reasonable to advance the
document.

> (5) Do portions of the document need review from a particular or from
>    broader perspective.

There is no use of formal language in the document and no need for
specific targeted reviews.

As previously noted, this document concerns deployment and use of
network management systems and so can benefit from additional reviews by
network operators. However, sufficient operator input has been receieved
to give confidence about the contents.

> (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?

No such 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.

All done. IPR responses can be seen at:

  Q. Wu: https://mailarchive.ietf.org/arch/msg/opsawg/zebmEbg9lOLZy9yYCPea94LIU6k/
  M. Boucadair : https://mailarchive.ietf.org/arch/msg/opsawg/MtYvDrUqjcSoPMSsTg_ZpvR0eTQ/
  D. Lopez: https://mailarchive.ietf.org/arch/msg/opsawg/zNP3w3IVZkffakWyk-pxBYuRFr8/
  C. Xie: https://mailarchive.ietf.org/arch/msg/opsawg/zyDDzrs0ZF9jBIRp1IP0CZcVBbE/
  L. Geng: https://mailarchive.ietf.org/arch/msg/opsawg/5TUtcJ22HCVPmb3TGD7QUu1rz6A/
  C. Jacquenet: https://mailarchive.ietf.org/arch/msg/opsawg/ugSjfI7ZH_dPa0WXeflDqpJJLmg/
  Luis Miguel Contreras Murillo: https://mailarchive.ietf.org/arch/msg/opsawg/n-9UACXuUvMmpCO6DDiIDqZrbVI/
  Oscar Gonzalez de Dios: https://mailarchive.ietf.org/arch/msg/opsawg/h-45h77DJiV7gkUpN5w3260hIqw/
  Weiqiang Cheng: https://mailarchive.ietf.org/arch/msg/opsawg/u3UKqjhZAn27R4J0Fm-eqAoC7Tc/
  Young Lee: https://mailarchive.ietf.org/arch/msg/opsawg/j06bIB8h0tuiJ1PRO5lSfnGOCy0/

> (8) Has an IPR disclosure been filed that references this document?

No.

> (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?

Reasonable support with no dissent.
I would say that part of the WG is not interested in the subject matter
and so had no opinion. But with a large list of authors and contributors
this catches the mood of the WG.

> (10) Has anyone threatened an appeal or otherwise indicated extreme
>      discontent?

No.

> (11) Identify any ID nits the Document Shepherd has found in this
>      document.

idnits is clean except for a number of referenced I-Ds that have moved
on to later revisions. That is picked up automatically the next time the
XML is processed.

> (12) Describe how the document meets any required formal review
>      criteria

No formal language used. No criteria to be met.

> (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?

All normative references are to published RFCs.

> (15) Are there downward normative references references (see
>      RFC 3967)?

No downrefs.

> (16) Will publication of this document change the status of any
>      existing RFCs?

No.

> (17) Describe the Document Shepherd's review of the IANA
>      considerations section.

The document makes no request for any IANA action.

An appropriate "null" IANA Considerations section is included.

> (18) List any new IANA registries that require Expert Review for
>      future allocations.

None.

> (19) Describe reviews and automated checks performed by the Document
>      Shepherd to validate sections of the document written in a formal
>      language.

No formal language is used in this document.

> (20) If the document contains a YANG module

The document does not contain a YANG module.