General Network Element Constraint Encoding for GMPLS-Controlled Networks
draft-ietf-ccamp-general-constraint-encode-20

Received changes through RFC Editor sync (changed abstract to 'Generalized Multiprotocol Label Switching (GMPLS) can be used to control a wide variety of technologies. In some of these technologies, network elements and links may impose additional routing constraints such as asymmetric switch connectivity, non-local label assignment, and label range limitations on links.

This document provides efficient, protocol-agnostic encodings for general information elements representing connectivity and label constraints as well as label availability. It is intended that protocol-specific documents will reference this memo to describe how information is carried for specific uses.')

[Ballot comment]
Some editorial points, as flagged by Jouni in his OPS-DIR review


Editorials (I use the idnits line numbering on version 17):

* line 124: WSON is never expanded. It might be obvious for the authors
  but expanding the acronym on the first use would be nice.

* Line 1157
  [Switch] G. Bernstein, Y. Lee, A. Gavler, J. Martensson, " Modeling
                                                          ^^^

* Line 303: The "Switching Cap" gets used as a short name for
  "Switching Capability" but that is not described anywhere. One the
  other hand for "Connectivity" a short name "Conn" is described.

* Line 355: The "RstType" gets introduced as a short name for
  "RestrictionType".

* Line 344: RestrictType
                  ^^^

* Line 708: "Note that that.."
                  ^^^^^^^^^^

* Line 742: "..Num Label bits"
                      ^^^ 's' missing

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-ccamp-general-constraint-encode-16, which is currently in Last Call, and has the following comments:

We understand that, upon approval of this document, there are no IANA Actions that need completion.

While it is helpful for the IANA Considerations section of the document to remain in place upon publication, if the authors prefer to remove it, IANA doesn't object.

If this assessment is not accurate, please respond as soon as possible.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (General Network Element Constraint Encoding for GMPLS Controlled Networks) to Proposed Standard


The IESG has received a request from the Common Control and Measurement
Plane WG (ccamp) to consider the following document:
- 'General Network Element Constraint Encoding for GMPLS Controlled
  Networks'
  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
ietf@ietf.org mailing lists by 2015-01-17. 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

  Generalized Multiprotocol Label Switching can be used to control a
  wide variety of technologies. In some of these technologies network
  elements and links may impose additional routing constraints such as
  asymmetric switch connectivity, non-local label assignment, and
  label range limitations on links.

  This document provides efficient, protocol-agnostic encodings for
  general information elements representing connectivity and label
  constraints as well as label availability. It is intended that
  protocol-specific documents will reference this memo to describe how
  information is carried for specific uses.

The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-ccamp-general-constraint-encode/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-ccamp-general-constraint-encode/ballot/


The following IPR Declarations may be related to this I-D:

  http://datatracker.ietf.org/ipr/1926/

AD review
======
Hi,

This I-D has been in the pipe for a very long time. Thanks for
persisting with it: hopefully we can stumble through the last stages
and achieve publication.

I have done my usual AD review. The intention is to apply some polish
and to catch any issues that would otherwise gum up IETF last call and
IESG review.

Set out below you will find a number of relatively minor editorial
points and questions. But there are quite a lot of them, so I think
you need to address them either by responding to my email with rebuttals
and explanations, or by updating the draft. I'm happy to discuss all/any
of the points.

I'll mark the I-D as "revised I-D needed" until we resolve this
discussion.

Thanks for the work,
Adrian

===

You have a reference to [WSON-Frame] in the first paragraph, but no
citation in the references section. I think it is Informative.

---

In section 1.1

  Note
  that this matrix does not represent any particular internal blocking
  behavior but indicates which input ports and labels (e.g.,
  wavelengths) could possibly be connected to a particular output
  port.

Should this read...

  which input ports and labels (e.g.,
  wavelengths) could possibly be connected to a particular port and
  label pair.

Further, you have

  The connectivity matrix is a
  conceptual M by N matrix representing the potential switched or
  fixed connectivity, where M represents the number of input ports and
  N the number of output ports.

This seems to have smudged the difference between port and label. Do you
not actually have a conceptual M*m by N*n where M represents the number
of input ports each with m labels and N the number of output ports each
with n labels?

---

Section 2 uses [RWA-Info] in a normative way. Please move the referenced
document into the Normative References section.

---

Section 2.1

Presumably you are anticipating more "Connectivity" types. I found it a
little hard to dream of one, but hey, perhaps the future will surprise
me. But will there be another 254 connectivity types? Or should this be
a 4 bit, 2 bit, or 1 bit field?

---

In section 2.1 the concept of a Matrix ID is introduced. I think you
need to discuss this concept in the introduction to section 2. You
need to explain that the ID is unique only on the advertising node, and
you need to explain why a node would have more than one matrix. You
probably also need to note whether a {port, label} can be present in
more than one matrix. Lastly, if two matrices have {sr port, src label,
dst port, dst label} for the same ports and labels, and the values
differ there is presumably some assumption.

I believe all of this is generic and not protocol specific, but maybe
it will help me understand why you need 255 matrices on any one node.

---

Section 2.2

  When more than one of these fields are present the
  resulting restriction is the intersection of the restrictions
  expressed in each field.

Do you really mean "intersection" and not "union". It seems to me that
the intersection of the restrictions is less of a restriction.

---

Section 2.2

For the explanation of RestrictionType you need to give a forward
pointer to Sections 2.2.1 through 2.2.5 so that the reader isn't
puzzled.

---

Section 2.2 needs to explain the "Additional Restriction Parameters per
RestrictionType" field.

---

Section 2.2.1

  In the case of the SIMPLE_LABEL the GeneralPortRestrictions (or
  MatrixSpecificRestrictions) format is given by:

What are GeneralPortRestrictions and MatrixSpecificRestrictions?

---

2.2.1 and 2.2.4 need to point forward to 2.6 for the definition of label
set.

---

2.2.3 needs a forward pointer to 2.6.2 for the explanation of label
range. Indeed, the whole of this section is hard to interpret. I can't
read it and apply any meaning to the protocol object.

Furthermore:

  It is assumed that
  both center label and range tuning can be done without causing
  faults to existing signals.

Is a passive voice assumption.  Who is assuming this? What if she is
wrong? Who is responsible for making the assumption correct?

---

2.2.5

  In this case the accompanying port set indicate that a label may be
  used at most once among the ports in the link set field.

Not only would a forward pointer to 2.3 be useful, but you need some
clarity between "link set" and "port set".

---

2.3

Why is  in angle brackets?

There are just two other uses of angle brackets in the document. Why?

---

2.3

Does the Action field need a registry to track values?

I am surprised that you think there may be 255 potential settings.

---

Section 2.3

  All Local Interface IP Address are supplied in
  the context of the advertising node

Aren't IP addresses scoped a little more widely?

---

Section 2.3

Wondering why you want a length field rather than a count field.

---

Section 2.4

Priority needs some explanation or reference. Priority with respect to
what?

  At least one priority
  level MUST be advertised that, unless overridden by local policy,
  SHALL be at priority level 0.

I cannot parse this at all!

---

Sections 2.3, 2.4, and 2.6 seems to have origins in section 2.2 and can
have the necessary forward pointers included.  But where does section
2.5 come from? Where does the "Shared Backup Labels Field" sit?

Assuming that question can be answered, the same issues apply as voiced
for section 2.4.

---

In 2.6 or its subsections you need to explain the Num Labels field.

The explanation of Length in 2.6 is a little lacking, as well...

  Length is the length in bytes of the entire field.

...which "field"? ... why do you need the label count and the length
field?

---

2.6.2

Curious effect if I set start label equal to end label but am required
to set num labels equal to 2.

---

2.6.3

Only support 4096 labels in a bitmap set? Really?

---

In the second example in A.2

"Length = 20 bytes" seems to be wrong
Why does every entry have "n  for lowest frequency"?

---

Section A.3

  This representation uses only 30 32-bit words.

But I count only 29 32-bit words.

---

In A.5 the two priority fields seem to be wrong. I expected

|1 0 0 0 0 0 0 0|

and

|1 1 1 1 1 1 1 1|

---

[G.694.1] seems to appear as a normative and informative reference.
Furthermore, it isn't actually referenced, but then neither is
[G.694.2].

Write up for draft-ietf-ccamp-general-constraint-encode

> 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)?

Standards Track

> Why is this the proper type of RFC? 

The document defines encodings (wire formats) for use in routing and
signaling protocols.

> 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 provides efficient, protocol-agnostic encodings for
  general information elements representing connectivity and label
  constraints as well as label availability. It is intended that
  protocol-specific documents will reference this memo to describe how
  information is carried for specific uses.

> 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?

This topic been discussed in the WG for a very long time, perhaps 6
years.  Support for the work has been tepid, but there are multiple
sets of contributors who would like to see the work result in proposed
standards.

> 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 provides background and an approach to extending
exiting RFCs for which there are implementations, but does not
itself define any protocol mechanisms.  The existing RFCs include
RFC3471, RFC3473, RFC4202, RFC4203.  This work is based on RFC6163.

> Personnel
>
>  Who is the Document Shepherd?

Lou Berger

> Who is the Responsible Area Director?

Adrian Farrel

> (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 Document Shepherd has reviewed the document as it has progressed
through the CCAMP WG, including as part of an extended WG last calls.
The Shepherd believes this document is ready for publication. This
document is part of a set of documents on WSON and final publication --
and at the AD's discretion, IETF LC -- should occur as a set.
The documents set includes:
    draft-ietf-ccamp-rwa-info
    draft-ietf-ccamp-general-constraint-encode
    draft-ietf-ccamp-rwa-wson-encode
    draft-ietf-ccamp-gmpls-general-constraints-ospf-te
    draft-ietf-ccamp-wson-signal-compatibility-ospf
    draft-ietf-ccamp-wson-signaling

> (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.

As part of the 2nd WG LC, both the OSPF WGs chairs were consulted. (But
didn't offer any input.)

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

No specific concerns.

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

Yes, via messages to/on the CCAMP WG list.

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

IPR has been disclosed for this document. This disclosure  resulted in a
number of messages on the list, including
http://www.ietf.org/mail-archive/web/ccamp/current/msg14169.html and
http://www.ietf.org/mail-archive/web/ccamp/current/msg14203.html

No suggestion of changing the WG document solution resulted from the
discussion. 

> (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? 

Good among interested parties. No objections from others.

> (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.)

Not to my knowledge.

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

The document passes tools idnits.

> (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?

None.

> (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.

None.

> (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 provides general protocol independent information
  encodings.  There is no IANA allocation request for the information
  elements defined in this document. IANA allocation requests will be
  addressed in protocol specific documents based on the encodings
  defined here.

> (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.

IPR declarations at August 12th 2013:

-Still missing:
Greg M. Bernstein(http://www.ietf.org/mail-archive/web/ccamp/current/msg15138.html) TO BE VERIFIED
Wataru Imajuku()
Jianrui Han()

- Received:
Anders Gavler (http://www.ietf.org/mail-archive/web/ccamp/current/msg15091.html)
Jonas Matensson (http://www.ietf.org/mail-archive/web/ccamp/current/msg15095.html)
Remi Theillaud(http://www.ietf.org/mail-archive/web/ccamp/current/msg15141.html)

Prepration for WG last call.

IPR declariations.
Diego Caviglia (http://www.ietf.org/mail-archive/web/ccamp/current/msg15004.html)
Anders Gavler (...)
Jonas Matensson (...)
Itaru Nishioka(http://www.ietf.org/mail-archive/web/ccamp/current/msg15009.html)
Rao Rajan(http://www.ietf.org/mail-archive/web/ccamp/current/msg14982.html)
Giovanni Martinelli (http://www.ietf.org/mail-archive/web/ccamp/current/msg15002.html)
Remi Theillaud()
Greg M. Bernstein()
Young Lee(http://www.ietf.org/mail-archive/web/ccamp/current/msg14988.html)
Dan Li(http://www.ietf.org/mail-archive/web/ccamp/current/msg14993.html)
Wataru Imajuku()
Jianrui Han()

Prepration for WG last call. IPR declariations.
Diego Caviglia (...)
Anders Gavler (...)
Jonas Matensson (...)
Itaru Nishioka()
Rao Rajan(http://www.ietf.org/mail-archive/web/ccamp/current/msg14982.html) Giovanni Martinelli ()
Remi Theillaud()
Greg M. Bernstein()
Young Lee(http://www.ietf.org/mail-archive/web/ccamp/current/msg14988.html)
Dan Li(http://www.ietf.org/mail-archive/web/ccamp/current/msg14993.html)
Wataru Imajuku()
Jianrui Han()