Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE
draft-ietf-pce-stateful-sync-optimizations-10

Request for posting confirmation emailed to previous authors: Edward Crabbe , Jan Medved , Dhruv Dhody , Xian Zhang , Ina Minei , pce-chairs@ietf.org, Robert Varga

[Ballot comment]
I generally agree with the secdir review.

TCP/AO is sadly fictional, so please don't
let's pretend it's usable to help here. Just
recommend TLS. (And add BCP195 too please.)

[Ballot comment]
(1) The Speaker Entity Identifier concerns me a lot because of the spoofing vector it introduces, and because I don't think the uniqueness is strongly specified.  I understand that the risk of spoofing is limited to the State Timeout Interval, but that is a long time:  at least 30 sec by default!  It looks like the main use case is to avoid state synchronization after an IP address change -- are there other? 

(2) By making TCP-AO/TLS "RECOMMENDED", this document is not in line with RFC5440, where only TCP-MD5 is mandatory.  I don't think the intent of this document is to Update RFC5440, is it?  Also, why would the recommendations for this extension be different than those in draft-ietf-pce-stateful-pce (which doesn't go beyond what RFC5440 mentions)?  If you do keep the current recommendation, then draft-ietf-pce-pceps should be a Normative reference.

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

The IANA Services Operator has completed its review of draft-ietf-pce-stateful-sync-optimizations-08.txt. If any part of this review is inaccurate, please let us know.

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

We understand that some of the actions requested in the IANA Considerations section of this document are dependent upon the approval of and completion of IANA Actions in another document: ietf-pce-stateful-pce.

First, in the PCEP-ERROR Object Error Types and Values subregistry of the Path Computation Element Protocol (PCEP) Numbers registry located at:

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

two new registrations will be made as follows:

Error-Type Meaning Reference
-------------+------------------------------+----------------------------
6 Mandatory Object missing [RFC5440]
Error-Value= TBD(suggested [ RFC-to-be ]
value 12): LSP-DB-VERSION TLV
missing
20 LSP State synchronization [I-D.ietf-pce-stateful-pce]
error
Error-Value= TBD(suggested [ RFC-to-be ]
value 2): LSP Database version
mismatch.
Error-Value=TBD(suggested [ RFC-to-be ]
value 3): The LSP-DB-VERSION
TLV Missing when state
synchronization avoidance is
enabled.
Error-Value=TBD(suggested [ RFC-to-be ]
value 4): Attempt to trigger a
synchronization when the
PCE triggered synchronization
capability has not been
advertised.
Error-Value=TBD(suggested [ RFC-to-be ]
value 6): No sufficient LSP
change information for
incremental LSP state
synchronization.
Error-Value=TBD(suggested [ RFC-to-be ]
value 7): Received an invalid
LSP DB Version Number

Second, in the PCEP TLV Type Indicators subregistry also in the Path Computation Element Protocol (PCEP) Numbers registry located at:

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

two new registrations will be made as follows:

Value: [ TBD-at-registration ]
Description: LSP-DB-VERSION
Reference: [ RFC-to-be ]

Value: [ TBD-at-registration ]
Description: SPEAKER-ENTITY-ID
Reference: [ RFC-to-be ]

We note that the authors have suggested the values 23 and 24 for these registrations.

Third, the STATEFUL-PCE-CAPABILITY TLV is to be defined in another draft[I-D.ietf-pce-stateful-pce] and, upon approval of that draft, a registry is requested to be created to manage the flags in the TLV. The current draft requests new registrations in the registry created upon approval of the other draft.

Bit Description Reference
TBD(suggested value 26) TRIGGERED-INITIAL-SYNC [ RFC-to-be ]
TBD(suggested value 27) DELTA-LSP-SYNC-CAPABILITY [ RFC-to-be ]
TBD(suggested value 28) TRIGGERED-RESYNC [ RFC-to-be ]
TBD(suggested value 30) INCLUDE-DB-VERSION [ RFC-to-be ]

The IANA Services Operator understands that these three actions are the only ones 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 only to confirm what actions will be performed.

Thank you,

Sabrina Tanamal
IANA Services Specialist
PTI

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: pce-chairs@ietf.org, jonathan.hardwick@metaswitch.com, pce@ietf.org, draft-ietf-pce-stateful-sync-optimizations@ietf.org, db3546@att.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE) to Proposed Standard


The IESG has received a request from the Path Computation Element WG
(pce) to consider the following document:
- 'Optimizations of Label Switched Path State Synchronization Procedures
  for a Stateful PCE'
  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 2017-02-28. 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


  A stateful Path Computation Element (PCE) has access to not only the
  information disseminated by the network's Interior Gateway Protocol
  (IGP), but also the set of active paths and their reserved resources
  for its computation.  The additional Label Switched Path (LSP) state
  information allows the PCE to compute constrained paths while
  considering individual LSPs and their interactions.  This requires a
  reliable state synchronization mechanism between the PCE and the
  network, PCE and path computation clients (PCCs), and between
  cooperating PCEs.  The basic mechanism for state synchronization is
  part of the stateful PCE specification.  This draft presents
  motivations for optimizations to the base state synchronization
  procedure and specifies the required Path Computation Element
  Communication Protocol (PCEP) extensions.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-pce-stateful-sync-optimizations/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-pce-stateful-sync-optimizations/ballot/


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

(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?

Proposed Standard.  The front page indicates that the document is on the standards track.  This is an appropriate type of RFC as the protocol it describes has been implemented and is intended for deployment, but has not yet seen widespread deployment.


(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.

Technical Summary:

A stateful Path Computation Element (PCE) is a PCE whose path computations take into account the resources and interactions of the currently active paths in the network.  A stateful PCE uses a reliable state synchronization mechanism to learn the set of active paths from its Path Computation Clients (PCCs) and peer stateful PCEs.  The basic state synchronization procedure is part of the stateful PCE specification.  This draft describes various optional optimizations to the state synchronization procedure, and specifies the required Path Computation Element Communication Protocol (PCEP) extensions.

Working Group Summary:

There was some strong opposition from members of the WG to publishing these optimizations in the base stateful PCE specification, because they wanted to keep the base specification as streamlined as possible.  The WG therefore decided instead to publish these optimizations separately from the base stateful PCE protocol.  Apart from this, there were no particular points of contention in the WG process.  The consensus behind publication of this document as a Standards Track RFC appears solid.

Document Quality:

There are at least two implementations of the optimizations described in this document.  The document has had several reviews by members of the working group.

There have been no MIB doctor, Media Type or other expert reviews done.

Personnel:

Jonathan Hardwick is the Document Shepherd.  Deborah Brungard is the Responsible Area Director.

(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.

I reviewed the document twice, at different stages of its lifetime, and submitted several comments to the authors.  These have been addressed to my satisfaction and I believe that the document 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.

No broader review is required.


(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 concerns.  Although the document concerns optimizations, and we must not optimize prematurely, nevertheless the optimizations are well-motivated by specific, realistic scenarios.


(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 IPR has been disclosed.


(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?

A reasonable cross-section of the WG expressed their support of advancing this document during last call, so the consensus appears fairly strong.


(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 http://www.ietf.org/tools/idnits/ and the Internet-Drafts Checklist). Boilerplate checks are not enough; this check needs to be thorough.

None.


(12) Describe how the document meets any required formal review criteria, such as the MIB Doctor, media type, and URI type reviews.

Not applicable.


(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?

There is a normative reference to [I-D.ietf-pce-stateful-pce].  Ideally, these two documents would progress to publication at the same time.


(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).

No issues.


(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.

This document does not request the creation of any new IANA registries.


(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.

Not applicable.