Path Computation Element Communication Protocol (PCEP) Extensions for GMPLS
RFC 8779

Received changes through RFC Editor sync (created alias RFC 8779, changed title to 'Path Computation Element Communication Protocol (PCEP) Extensions for GMPLS', changed abstract to 'A Path Computation Element (PCE) provides path computation functions for Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS) networks. Additional requirements for GMPLS are identified in RFC 7025.

This memo provides extensions to the Path Computation Element Communication Protocol (PCEP) for the support of the GMPLS control plane to address those requirements.', changed pages to 38, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2020-07-21, changed IESG state to RFC Published)

[Ballot comment]
Thank you for addressing my Discuss points!

I do have some additional comments on the -15.

Section 2.3

I'm still a bit concerned that the references linked from Table 4 may not
provide a clear description of what count as Traffic Parameters for our
purposes (and how they are encoded), but not in a way that I can express
more concretely.  Perhaps this is made clear by some RSVP-TE documents
with which I am not familiar.

ection 2.5.1

  root and other endpoints TLVs are the leaves.  The root endpoint MUST
  be the same for all END-POINTS objects.  If the root endpoint is not

I'm not sure how broadly scoped this restriction is -- it is, e.g., per-LSP?

Section 2.5.2.5

  with L bit cleared.  At most 2 LABEL_SET TLVs MAY be present with the
  O bit set, with at most one of these having the U bit set and at most
  one of these having the U bit cleared.  For a given U bit value, if

This went MUST->MAY in this rev, though I think it might be fine to just use
a lowercase "may", since the requirements language doesn't map terribly well
to the restriction we're making.

[Ballot comment]
Hi,

thanks for this document. I have a discuss point that shouldn't be difficult to resolve:

Why do you define a flag field in the GMPLS-CAPABILITY TLV if you don't have any flag?
I guess the easy answer is that there might be some in the future.
If so, I tend to think that creating a registry for that field would be a good thing to do now.

-m

[Ballot discuss]
This document makes some well-needed extensions to existing PCEP
concepts such as bandwidth, but I'm not convinced that the way they
interact with existing PCEP functionality is sufficiently well specified
to admit interoperable implementation.  Specifically, we introduce the
generalized bandwidth structures and reuse that encoding for the
generalized load balancing structures, which includes a notion of
"minimum bandwidth specification".  But now that the bandwidth
specification is a compound data structure instead of a scalar type,
it's not guaranteed that we have a strict linear ordering with
well-defined minimum.  If we consider the specific case of Intserv, do I
insist upon all three of the minimum bucket rate, minimum bucket size,
and minimum peak data rate?  Or perhaps I only care about the peak data
rate and not the bucket size/rate.  We need more text in order to
specify what "minimum" actually means/measures.

Similarly, I'm not sure all the referenced generalized bandwidth
types/traffic parameters in Section 2.3 clearly indicate which
structures/fields we are to incorporate by reference (see COMMENT).

Section 2.1.2 says:

  GMPLS-CAPABILITY TLV it is RECOMMENDED that the PCC does not make use
  of the objects and TLVs defined in this document.

Why is this not "the PCC MUST NOT make use of the objects and TLVs
defined in this document"?  Ignoring the peer's (non-)advertisement and
plowing ahead seems like a recipe for non-interoperability.

Section 2.5.1 notes that:

      ::=
        []
      [ []]...


  For endpoint type Point-to-Multipoint, several endpoint objects MAY
  be present in the message and each represents a leave, exact meaning
  depend on the endpoint type defined of the object.

If all s represent leaves, then how is the head node
specified?

I couldn't find a full spcification for some of the fields in the XRO
Label subobject (Section 2.7) by chasing the indicated references (see
COMMENT).

[Ballot comment]
Section 1

Please expand OTN and WSON on first use.

Section 1.4

It's very unclear to me what kind of support, from/by what entities/data
structures, under what conditions, these tables are attempting to
indicate.

We should probably be consistent whether we talk about just "FOO" or
"FOO object" as the hanging text for these bulleted lists.

  From [RFC8282]:

  o  SWITCH-LAYER: address requirements (1, 2 and 3) for the TE-LSP and
      indicates which layer(s) should be considered, can be used to
      represent the RSVP-TE generalized label request.  [...]

nit: this looks like a comma splice.

  The PCEP extensions defined later in this document to cover the gap
  are:

      Two new object types are introduced for the BANDWIDTH object
      (Generalized bandwidth, Generalized bandwidth of existing TE-LSP
      for which a reoptimization is requested).

I'm confused by this language "new object types are introduced for the
BANDWIDTH object".  My understanding was that objects did not nest: that
is, objects have a given structure and can sometimes contain TLVs, but
do not contain other objects.  So, my current understanding is that new
objects are introduced that can appear where the BANDWIDTH object would
previously have appeared, but they are separate object (type)s from the
RFC 5440 BANDWIDTH objects.  (This language is used in the next couple
items as well.)  To be clear, this is at most an editorial
consideration, essentially whether to use "introduced for" or something
like "introduced akin to".

Section 2.1.2

                                                  If the PCE does not
  include the GMPLS-CAPABILITY TLV in the OPEN message and the PCC does
  include the TLV, it is RECOMMENDED that the PCC indicates a mismatch
  of capabilities.  Moreover, in case that the PCC does not receive the

Indicate how, to whom?

Section 2.2

This granularity applies to all links in the path, right?  So I can't
request label-level granularity for one hop and indicate that I only
care about node-level granularity for the other hops?

Section 2.3

[similar comments apply here to what I mentioned at the end of Section
1.4]

  The Bw Spec Type correspond to the RSVP-TE SENDER_TSPEC (Object Class
  12) C-Types

Should we ask IANA to update the SENDER_TSPEC registry to note that it
is used for PCEP as well as RSVP?

  The encoding of the fields Generalized Bandwidth and Reverse
  Generalized Bandwidth is the same as the Traffic Parameters carried
  in RSVP-TE, it can be found in the following references.

                      Object Type Name      Reference

                      2          Intserv  [RFC2210]
                      4          SONET/SDH [RFC4606]
                      5          G.709    [RFC4328]
                      6          Ethernet  [RFC6003]
                      7          OTN-TDM  [RFC7139]
                      8          SSON      [RFC7792]

It's quite confusing to have the table heading be just "object type"
when this is the value in the field named "Bw Spec Type" and corresponds
to class type values in the SENDER_TSPEC registry.

Also, I looked up the Intserv case, and RFC 2210 doesn't really give me
a clear picture of what I'm supposed to encode as the "transport
parameters".  I think it's supposed to be the 12-octet assembly
consisting of the token bucket rate, token bucket size, and peak data
rate, but I have very low confidence in that assessment.  On the other
hand, RFC 4606 has a very nice data structure layout in Section 2.1,
"SONET/SDH Traffic Parameters".  On the gripping hand, there's not a
clear "bandwidth" number in that structure that I can apply a comparison
to for load-balancing purposes.  It doesn't look like I'll have time to
check the other four cases right now, but that will need to be done
before final publication.

Section 2.4

I'm having trouble parsing:

  The LOAD-BALANCING object [RFC5440] is used to request a set of
  maximum Max-LSP TE-LSP having in total the bandwidth specified in
  BANDWIDTH, each TE-LSP having a minimum of bandwidth.

Is it intended to read:

  The LOAD-BALANCING object [RFC5440] is used to request allocation of a set of
  at most Max-LSP TE-LSPs, having in total the bandwidth specified in
  BANDWIDTH, with each TE-LSP having at least a specified minimum bandwidth.

?

[similar comments apply here to what I mentioned at the end of Section
1.4]

  Bandwidth Spec Length (16 bits): the total length of the Min
  Bandwidth Spec field.  It is to be noted that the RSVP-TE traffic
  specification MAY also include TLV different from the PCEP TLVs.  The
  length MUST be strictly greater than 0.

It's not entirely clear to me why the note about different TLVs in
RSVP-TE and PCEP belongs here.

Section 2.5.1

              Endpoints label restriction may not be part of the RRO or
  IRO, they can be included when following [RFC4003] in signaling for
  egress endpoint, but ingress endpoint properties can be local to the
  PCC and not signaled.  [...]

nit: the first comma looks like a comma splice.

                      A PCE not supporting a given Endpoint Type SHOULD
  respond with a PCErr with Error Type 4, Value TBD "Unsupported
  endpoint type in END-POINTS Generalized Endpoint object type".  [...]

s/TBD/TBA-15/

                                            The TLVs present in the
  request object body MUST follow the following [RFC5511] grammar:

It feels a bit like a type error to use RBNF to describe the layout
of TLVs within a TLV block, as RBNF acts on objects.

Section 2.5.2.4

  The LABEL-REQUEST TLV indicates the switching capability and encoding
  type of the following label restriction list for the endpoint.  Its
  format and encoding is the same as described in [RFC3471] Section 3.1
  Generalized label request.  [...]

Presumably the "Its" refers to just the value portion of the TLV?
That should probably be stated explicitly.

Section 2.5.2.5

Is there any reason for the section title to not be "LABEL-SET TLV" for
consistency with the other sections?

  A LABEL-SET TLV represents a set of possible labels that can be used
  on an interface.  If the L bit is cleared, the label allocated on the
  first endpoint MUST be within the label set range.  [...]

Is this MUST binding on the PCC that generates a request, or on the
computed LSP returned by the PCE?

  A LABEL-SET TLV with the O and L bit set MUST trigger a PCErr message
  with error type="Reception of an invalid object" error value="Wrong
  LABEL-SET TLV present with O and L bit set".

  A LABEL-SET TLV with the O bit set and an Action Field not set to 0
  (Inclusive list) or containing more than one subchannel MUST trigger
  a PCErr message with error type="Reception of an invalid object"
  error value="Wrong LABEL-SET TLV present with O bit and wrong
  format".

  If a LABEL-SET TLV is present with O bit set, the R bit of the RP
  object MUST be set, otherwise a PCErr message MUST be sent with error
  type="Reception of an invalid object" error value="LABEL-SET TLV
  present with O bit set but without R bit set in RP".

nit: I don't know if it makes more sense to use the TBA-25, TBA-26, and
TBA-24 values in these descriptions.

Section 2.6

  The IRO as defined in [RFC5440] is used to include specific objects
  in the path.  RSVP-TE allows to include label definition, in order to
  fulfill requirement 13 of [RFC7025] the IRO needs to support the new
  subobject type as defined in [RFC3473]:

nit: this looks like a comma splice.  (A similar construction appears in
Section 2.7 as well.)

Section 2.7

      U (1 bit): see [RFC3471].

      C-Type (8 bits): the C-Type of the included Label Object as
      defined in [RFC3471].

      Label: see [RFC3471].

Sorry, where exactly in RFC 3471?  I do not see discussion of a U bit
or C-Type therein.  (Perhaps RFC 3473 was intended?  Though, RFC 3473
seems to refer back to 3471 for the U parameter, again without section
reference.)

Section 6

It seems that a malicious PCC might be able to effect a denial of
service attack on the PCE by attempting to make many requests that
consume lots of resources (whether on the PCE itself or in the managed
network elements).

                In addition Technology specific data plane mechanism
  can be used (following [RFC5920] Section 5.8) to verify the data
  plane connectivity and deviation from constraints.

nit: "In addition, technology-specific"

Appendix A

It's not entirely clear to me why this specific group of examples was
chosen and no others.  (The appendix does not seem to be referenced from
elsewhere in the document, so it appears fairly random to a reader
making it that far.)

[Ballot discuss]
Hi,

thanks for this document. I have a discuss point that shouldn't be difficult to resolve:

Why do you define a flag field in the GMPLS-CAPABILITY TLV if you don't have any flag?
I guess the easy answer is that there might be some in the future.
If so, I tend to think that creating a registry for that field would be a good thing to do now.

-m

[Ballot discuss]
(1) Section 6, Per “The answer can make that the LSP traverses some geographical place known to the attacker where some sniffing devices could be installed”, this is a concern.  Good that it is here.  However, it seems like the consequences could be even more expansive – confidentiality (sniffing), integrity (modifying the traffic) or availability (choose to drop it).

(2) Section 6, [RFC8253] is mentioned a few times as having a variety of capabilities to mitigate the described threats.  This is the right reference.  However, the current text doesn’t explicitly state whether and how this guidance should be followed (should, must, is recommended?)

[Ballot comment]
(1) Section 2.3, Nit (missing commas and periods),
s/(SDH/SONET, G.709, ATM, MEF etc)/
(SDH/SONET, G.709, ATM, MEF, etc.)/

(2) In a few section.  Typo (duplicate “section Section”).  Recommend global s/section Section/Section/g

(3) Section 6.  Duplicate word.  s/against against/against/

[Ballot comment]
I think Section 2.1.2 needs to better explain what happens when a PCC sends extensions but the recipient does not support them.

Please respond to the Gen-ART review.

[Ballot comment]
* Section 2.5.2

"In this object type the order of the TLVs MUST be followed according to the object type definition."

Not sure what this means. Can you clarify?

* Section 2.7

"C-Type (8 bits): the C-Type of the included Label Object as defined in [RFC3471]."

I could not find any references to C-Types in RFC3471. Shouldn't you be referring to RFC3473 instead? I have a similar comment for the Label field.

[Ballot comment]
Purely editorial comment:
I would recommend to move most of the gap analysis of section 1 (actually most of the text of the whole section) into the appendix and only summarise the extensions specified in this doc instead.

nit:
sec 6: s/In order to protect against against the malicious PCE case/In order to protect against the malicious PCE case/ -> 2x against

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

The IANA Functions Operator has completed its review of draft-ietf-pce-gmpls-pcep-extensions-12. If any part of this review is inaccurate, please let us know.

The IANA Functions Operator has a question about one of the actions requested in the IANA Considerations section of this document.

The IANA Functions Operator understands that, upon approval of this document, there are nine actions which we must complete.

First, in the PCEP Objects registry on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

a set of object types are to be added to existing objects in the registry.

Two new object-types to the existing object BANDWIDTH as follows:

Object-Class Value: 5
Name: BANDWIDTH

the following two, new object types:

number: [ TBD-at-Registration ]
description: Generalized bandwidth
Reference: [ RFC-to-be Section 2.3]

number: [ TBD-at-Registration ]
description: Generalized bandwidth of an existing TE-LSP for which a reoptimization is requested
Reference: [ RFC-to-be Section 2.3]

Two new object-types to the existing object LOAD-BALANCING as follows:

Object-Class Value: 14
Name: LOAD-BALANCING

the following single, new object type:

number: [ TBD-at-Registration ]
description: Generalized Load Balancing
Reference: [ RFC-to-be Section 2.4]

Two new object-types to the existing object END-POINTS as follows:

Object-Class Value: 4
Name: END-POINTS

the following single, new object type:

number: [ TBD-at-Registration ]
description: Generalized Load Balancing
Reference: [ RFC-to-be Section 2.5]

Second, a new registry is to be created called the "END-POINTS Object, Object Type Generalized Endpoint" registry. The new registry will be located on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

IANA Question --> Section 5.2 of the current document says "New endpoint type in the Reserved range MAY be allocated by an IETF consensus action." IETF Consensus Action is not a well-known registration policy. Please see section 4 of [RFC8126] for a description of well-known policies and choose the policy best suited for this new registry.

The are initial registrations in the new registry as follows:

Value Type Meaning Reference:
-------+-------------------+-------------------------------+----------------
0 Point-to-Point [ RFC-to-be ]
1 Point-to-Multipoint New leaves to add [ RFC-to-be ]
2 Old leaves to remove [ RFC-to-be ]
3 Old leaves whose path can be [ RFC-to-be ]
modified/reoptimized
4 Old leaves whose path has to be [ RFC-to-be ]
left unchanged
5-244 Reserved
245-255 Experimental range

Third, in the PCEP TLV Type Indicators registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

eight, new TLV Type Indicators are to be registered as follows:

Value: [ TBD-at-Registration ]
Description: IPV4-ADDRESS
Reference: [ RFC-to-be Section 2.5.2.1]

Value: [ TBD-at-Registration ]
Description: IPV6-ADDRESS
Reference: [ RFC-to-be Section 2.5.2.2]

Value: [ TBD-at-Registration ]
Description: UNNUMBERED-ENDPOINT
Reference: [ RFC-to-be Section 2.5.2.3]

Value: [ TBD-at-Registration ]
Description: LABEL-REQUEST
Reference: [ RFC-to-be Section 2.5.2.4]

Value: [ TBD-at-Registration ]
Description: LABEL-SET
Reference: [ RFC-to-be Section 2.5.2.5]

Value: [ TBD-at-Registration ]
Description: SUGGESTED-LABEL-SET
Reference: [ RFC-to-be Section 2.5.2.5]

Value: [ TBD-at-Registration ]
Description: PROTECTION-ATTRIBUTE
Reference: [ RFC-to-be Section 2.8]

Value: [ TBD-at-Registration ]
Description: GMPLS-CAPABILITY
Reference: [ RFC-to-be Section 2.1.2]

IANA notes that the authors have provided suggested values for these eight new TLVs.

Fourth, in the RP Object Flag Field registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

a single, new registration is to be made as follows:

Bit: [ TBD-at-Registration ]
Description: Routing granularity (RG)
Reference: [ RFC-to-be Section 2.2]

Fifth, in the PCEP-ERROR Object Error Types and Values registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

additional error values are to be added to two, existing error values as follows:

For:
Type=4 Not supported object [RFC5440]

The following additional error types:

[ TBD-at-Registration ]: Bandwidth Object type TBA or TBA not [ RFC-to-be ]
supported.
[ TBD-at-Registration ]: Unsupported endpoint type in END-POINTS [ RFC-to-be ]
Generalized Endpoint object type
[ TBD-at-Registration ]: Unsupported TLV present in END-POINTS [ RFC-to-be ]
Generalized Endpoint object type
[ TBD-at-Registration ]: Unsupported granularity in the RP object [ RFC-to-be ]
flags

For:
Type? Reception of an invalid object [RFC5440]

The following additional error types:

[ TBD-at-Registration ]: Bad Bandwidth Object type [ RFC-to-be ]
[XXXXX](Generalized bandwidth) or
[YYYYY](Generalized bandwidth of existing
TE-LSP for which a reoptimization is
requested).
[ TBD-at-Registration ]: Unsupported LSP Protection Type in [ RFC-to-be ]
PROTECTION-ATTRIBUTE TLV.
[ TBD-at-Registration ]: Unsupported LSP Protection Flags in [ RFC-to-be ]
PROTECTION-ATTRIBUTE TLV.
[ TBD-at-Registration ]: Unsupported Secondary LSP Protection [ RFC-to-be ]
Flags in PROTECTION-ATTRIBUTE TLV.
[ TBD-at-Registration ]: Unsupported Link Protection Type in [ RFC-to-be ]
PROTECTION-ATTRIBUTE TLV.
[ TBD-at-Registration ]: Unsupported Link Protection Type in [ RFC-to-be ]
PROTECTION-ATTRIBUTE TLV.
[ TBD-at-Registration ]: LABEL-SET TLV present with 0 bit set but [ RFC-to-be ]
without R bit set in RP.
[ TBD-at-Registration ]: Wrong LABEL-SET TLV present with 0 and L [ RFC-to-be ]
bit set.
[ TBD-at-Registration ]: Wrong LABEL-SET with O bit set and wrong [ RFC-to-be ]
format.

For the Bad Bandwidth Object type error value the value [XXXXX] will be replaced by the object type number for Object-Class Value: 5, Name: BANDWIDTH; Generalized bandwidth number that was created in the first step above. For the Bad Bandwidth Object type error value the value [YYYYY] will be replaced by the object type number for Object-Class Value: 5, Name: BANDWIDTH; Generalized bandwidth of an existing TE-LSP for which a reoptimization is requested number that was created in the first step above.

IANA notes that the authors have provided suggested values for these error values.

Sixth, also in the PCEP-ERROR Object Error Types and Values registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

a new error type and associated error values are to be registered as follows:

The new error type:
Type=[ TBD-at-Registration ] Path computation failure [ RFC-to-be ]

Its associated error values:
Value=0 Unassigned. [ RFC-to-be ]
[ TBD-at-Registration ]: Unacceptable request message. [ RFC-to-be ]
[ TBD-at-Registration ]: Generalized bandwidth value not [ RFC-to-be ]
supported.
[ TBD-at-Registration ]: Label Set constraint could not be met. [ RFC-to-be ]
[ TBD-at-Registration ]: Label constraint could not be met. [ RFC-to-be ]

Seventh, in the NO-PATH-VECTOR TLV Flag Field also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

six, new registrations will be made as follows:

Bit: [ TBD-at-Registration ]
Description: Protection Mismatch
Reference: [ RFC-to-be ]

Bit: [ TBD-at-Registration ]
Description: No Resource
Reference: [ RFC-to-be ]

Bit: [ TBD-at-Registration ]
Description: Granularity not supported
Reference: [ RFC-to-be ]

Bit: [ TBD-at-Registration ]
Description: No endpoint label resource
Reference: [ RFC-to-be ]

Bit: [ TBD-at-Registration ]
Description: No endpoint label resource in range
Reference: [ RFC-to-be ]

Bit: [ TBD-at-Registration ]
Description: No label resource in range
Reference: [ RFC-to-be ]

IANA notes that the authors have provided suggested values for these six new registrations.

Eighth, the IRO Subobjects registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

a single, new registration will be made as follows:

Value: [ TBD-at-Registration ]
Description: Label
Reference: [ RFC-to-be ]

IANA notes that the authors suggest the value 3 for this registration.

Ninth, the XRO Subobjects registry also on the Path Computation Element Protocol (PCEP) Numbers registry page located at:

https://www.iana.org/assignments/pcep/

a single, new registration will be made as follows:

Value: [ TBD-at-Registration ]
Description: Label
Reference: [ RFC-to-be ]

IANA notes that the authors suggest the value 3 for this registration.

The IANA Functions Operator understands that these are the only actions required to be completed upon approval of this document.

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

Thank you,

Sabrina Tanamal
Senior IANA Services Specialist

The following Last Call announcement was sent out (ends 2018-10-29):

From: The IESG
To: IETF-Announce
CC: Julien Meuric , db3546@att.com, pce@ietf.org, pce-chairs@ietf.org, draft-ietf-pce-gmpls-pcep-extensions@ietf.org, julien.meuric@orange.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (PCEP extensions for GMPLS) to Proposed Standard


The IESG has received a request from the Path Computation Element WG (pce) to
consider the following document: - 'PCEP extensions for GMPLS'
  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 2018-10-29. Exceptionally, comments may be
sent to iesg@ietf.org instead. In either case, please retain the beginning of
the Subject line to allow automated sorting.

Abstract


  This memo provides extensions to the Path Computation Element
  communication Protocol (PCEP) for the support of GMPLS control plane.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-pce-gmpls-pcep-extensions/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-pce-gmpls-pcep-extensions/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)?
-> Standards Track

Why is this the proper type of RFC?
-> It specifies protocol extensions.

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

  Although [RFC4655] defines the PCE architecture and framework for
  both MPLS and GMPLS networks, most preexisting PCEP RFCs [RFC5440],
  [RFC5521], [RFC5541], [RFC5520] are focused on MPLS networks, and do
  not cover the wide range of GMPLS networks.  This document
  complements these RFCs by addressing the extensions required for
  GMPLS applications and routing requests, for example for OTN and WSON
  networks.

Working Group Summary

Though uncontroversial, this work had a long life. Some other work with strong market demand (stateful PCE, mainly) came along and this document got stuck for a while in the WG's and chairs' backlog.

Document Quality

  Are there existing implementations of the protocol?
-> There are several implementations, commercial and open source, of the base protocol. The extensions from this document were implemented (at least partially) by some work from the research community. Open source (OpenDaylight) is in the pipe.

Have a
  significant number of vendors indicated their plan to
  implement the specification?
-> At lest two vendors worked on the document. The implementation by a few optical vendors is mentioned by some (available) research publications.

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?
-> N/a

Personnel

  Who is the Document Shepherd?
-> Julien Meuric

Who is the Responsible Area Director?
->  Deborah Brungard

(3) Briefly describe the review of this document that was performed by
the Document Shepherd.  If this version of the document is not ready
for publication, please explain why the document is being forwarded to
the IESG.
-> Shepherd's comments have been addressed, it 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

(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.
-> N/a

(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.
-> None

(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? 
-> There was a clear consensus on the document. Several other living documents rely on this one, one of them being blocked on it.

(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.
-> Done

(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.
-> Checked
Confirm that any referenced IANA registries have been clearly identified.
-> OK
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).
-> N/a

(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