Service Models Explained
draft-ietf-opsawg-service-model-explained-05

[Ballot comment]
Please consider comments from the Routing Area Directorate review.

I think this document is useful as there are many "service definitions" in the industry. As the document says, the distinction is dependent on the definer, and that is ok. This document scopes IETF's use of the term. It would help clarify the document's intent if repeated this more than the one sentence in section 6.4.

As the Routing Area Directorate reviewer (Dave) noted, there are multiple places which could be improved and it is why I'm a "no objection" vs. a "yes" as these may seem small, but they do change the tone of the document, especially as this document will hopefully be used by other SDOs to understand our work, e.g.:

- Section 5 on Possible causes of confusion: "The confusion arises not only because of the use of the word "service" in both cases, but also because network operators may offer both types of service to their customers." This sentence is very confusing:-) It infers confusion is caused by the operator on the use of their term for a service "but ..because network operators may offer both". But as the document itself says - service depends on the context. As Dave says, don't confuse the reader further. Just delete this sentence and say these are different types of services, it's not the use of the term "service" which is confusing:-)
- Section 6.4 on MEF Architecture "Thus, it may be impractical to fit IETF service models into the MEF Forum LSO architecture." Why are you pre-judging the applicability? Dave noted this also. Suggest delete this sentence. And previous sentence - IETF's work..typically smaller offering/s/IETF's work .. is a different scope. I don't think IETF's work is a "smaller offering", it's just different. The sentence infers don't use IETF's work, use MEF Forum's if want a complete package.
- And many more examples in Dave's careful review.

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

The IANA Services Operator has reviewed draft-ietf-opsawg-service-model-explained-04, 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
IANA Services Specialist

The following Last Call announcement was sent out (ends 2017-10-11):

From: The IESG
To: IETF-Announce
CC: draft-ietf-opsawg-service-model-explained@ietf.org, opsawg-chairs@ietf.org, Tianran Zhou , opsawg@ietf.org, zhoutianran@huawei.com, warren@kumari.net
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Service Models Explained) to Informational RFC


The IESG has received a request from the Operations and Management Area
Working Group WG (opsawg) to consider the following document: - 'Service
Models Explained'
  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
ietf@ietf.org mailing lists by 2017-10-11. 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 IETF has produced many modules in the YANG modeling language.
  The majority of these modules are used to construct data models to
  model devices or monolithic functions.

  A small number of YANG modules have been defined to model services
  (for example, the Layer Three Virtual Private Network Service Model
  produced by the L3SM working group and documented in RFC 8049).

  This document describes service models as used within the IETF, and
  also shows where a service model might fit into a Software Defined
  Networking architecture.  Note that service models do not make any
  assumption of how a service is actually engineered and delivered for
  a customer; details of how network protocols and devices are
  engineered to deliver a service are captured in other modules that
  are not exposed through the Customer-Provider Interface.




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

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-opsawg-service-model-explained/ballot/


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

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

The IANA Services Operator has reviewed draft-ietf-opsawg-service-model-explained-03, 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
IANA Services Specialist

The following Last Call announcement was sent out (ends 2017-09-20):

From: The IESG
To: IETF-Announce
CC: draft-ietf-opsawg-service-model-explained@ietf.org, opsawg-chairs@ietf.org, Tianran Zhou , opsawg@ietf.org, zhoutianran@huawei.com, warren@kumari.net
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Service Models Explained) to Informational RFC


The IESG has received a request from the Operations and Management Area
Working Group WG (opsawg) to consider the following document: - 'Service
Models Explained'
  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
ietf@ietf.org mailing lists by 2017-09-20. 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 IETF has produced many data modules in the YANG modeling
  language.  The majority of these modules are used to construct data
  models to model devices or monolithic functions.

  A small number of YANG modules have been defined to model services
  (for example, the Layer Three Virtual Private Network Service Model
  produced by the L3SM working group and documented in RFC 8049).

  This document describes service models as used within the IETF, and
  also shows where a service model might fit into a Software Defined
  Networking architecture.  Note that service models do not make any
  assumption of how a service is actually engineered and delivered for
  a customer; details of how network protocols and devices are
  engineered to deliver a service are captured in other models that are
  not exposed through the Customer-Provider Interface.




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

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-opsawg-service-model-explained/ballot/


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 24 February 2012.
>
>(1) What type of RFC is being requested (BCP, Proposed Standard,
>Internet Standard, Informational, Experimental, or Historic)? 

Informational.

>Why is this the proper type of RFC? 

The document helps to clarify service model related concepts and
establish a common categorization rather than any specific mechanism.

>Is this type of RFC indicated in the
>title page header?

Yes.   

>(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
>
>  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 service models including scope and purpose as
used within the IETF, and shows where a service model might fit into a
Software Defined Networking architecture. It also clarifies what a
service model is not, and dispels some common misconceptions.
 
>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?

There was debate on the "network service model" concept in RFC 8199 .
This was solved by coordinating the cross WG discussion with NETMOD
during both the WG adoption call and WG LC.

>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?

This document has received extensive input and review. It has already
been used to direct L2SM and L3SM work.
 
>Personnel
>
>  Who is the Document Shepherd?

Tianran Zhou
>
>  Who is the Responsible Area
>  Director?

Warren Kumari will normally serve as Responsible AD.

>(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 the draft multiple times and ensured that
appropriate review was conducted in and out of the WG.

>(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.

This document provides a taxonomy for YANG models, especially for
service models. It's expected that the classification boundaries are at
times blurry, and the classification criteria may change over time.
For some existing YANG modules, it's hard to find one corresponding
category. The information given by this document is a starting point
and shows current knowledge/experience on service models used within
IETF.

>(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.

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

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? 

Solid among interested 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 https://www.ietf.org/tools/idnits/ and the Internet-Drafts
>Checklist). Boilerplate checks are not enough; this check needs to be
>thorough.

The document passed ID nits.

>(12) Describe how the document meets any required formal review
>criteria, such as the MIB 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.

>(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 5226).

This document makes no requests for IANA action.


>(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.

N/A.

>(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, etc.

N/A.