Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP) Pseudowires Protection
draft-ietf-pals-mpls-tp-dual-homing-coordination-06

[Ballot comment]
This should really be a DISCUSS, but I trust the shepherding AD to make sure that it is resolved:

At the beginning of page 6 there are 2 fields: Version and Flags which I don't think are described.

[Ballot comment]
Just a couple of editorial comments:

- Abstract: The parenthetical phrase " (management plane based)" makes the sentence structure more confusing that if the phrase were simply removed.

- Section 1: A few abbreviations that were expanded in the abstract should be expanded again in the body.

[Ballot comment]
Sorry one more editorial comment:

- In section 3.1 it would be good to further clarify what's meant by 'local request or a remote request', especially when and who is doing the remote request?

Minor mostly editorial comments:

1) When I first saw "DHC Code Point" in figure 2, I was slightly confused because this doesn't show in the rest of the doc anymore. Maybe rename to 'DHC channel type' or use the same term in the text or directly put the value in there that will be assigned by IANA.

2) 3.1.:"After the transmission of the three messages, the
  dual-homing PE MUST send the most recently transmitted Dual-Node
  Switching TLV periodically to the other dual-homing PE on a continual
  basis using the DHC message."
  This is only if the protection is active, right?

3) 3.2.:"Whenever a change of service PW status is detected by a dual-homing
  PE, it MUST be reflected in the PW Status TLV and sent to the other
  dual-homing PE immediately using the 3 consecutive DHC messages.
  This way, both dual-homing PEs have the status of the working and
  protection PW consistently."
  Note, it's possible that all three messages get lost. If you want to make sure you stay in sync, you need an explicit mechanism for reliability, e.g. sending an ack.

[Ballot comment]
Stephen also noted the SecDir review and text provided.  I also think this should be incorporated to explain the security considerations added by this draft. https://mailarchive.ietf.org/arch/msg/secdir/hE2TffVz-by4u001aSosi8JK6WI

[Ballot comment]
Minor mostly editorial comments:

1) When I first saw "DHC Code Point" in figure 2, I was slightly confused because this doesn't show in the rest of the doc anymore. Maybe rename to 'DHC channel type' or use the same term in the text or directly put the value in there that will be assigned by IANA.

2) 3.1.:"After the transmission of the three messages, the
  dual-homing PE MUST send the most recently transmitted Dual-Node
  Switching TLV periodically to the other dual-homing PE on a continual
  basis using the DHC message."
  This is only if the protection is active, right?

3) 3.2.:"Whenever a change of service PW status is detected by a dual-homing
  PE, it MUST be reflected in the PW Status TLV and sent to the other
  dual-homing PE immediately using the 3 consecutive DHC messages.
  This way, both dual-homing PEs have the status of the working and
  protection PW consistently."
  Note, it's possible that all three messages get lost. If you want to make sure you stay in sync, you need an explicit mechanism for reliability, e.g. sending an ack.

[Ballot comment]

- The secdir review [1] raised some good points that
I believe the authors have agreed to address, but
that's yet to happen.

[1] https://mailarchive.ietf.org/arch/search/?email_list=secdir&gbt=1&index=hE2TffVz-by4u001aSosi8JK6WI

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

The IANA Services Operator has completed its review of draft-ietf-pals-mpls-tp-dual-homing-coordination-05.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 two actions which we must complete.

First, in the MPLS Generalized Associated Channel (G-ACh) Types (including Pseudowire Associated Channel Types) subregistry of the Generic Associated Channel (G-ACh) Parameters registry located at:

http://www.iana.org/assignments/g-ach-parameters/

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

Value: [ TBD-at-registration ]
Description: MPLS-TP Dual-Homing Coordination message
Reference: [ RFC-to-be ]

Second, a new registry is to be created called the MPLS-TP DHC TLVs registry. The new registry is to be located in the existing Generic Associated Channel (G-ACh) Parameters registry located at:

http://www.iana.org/assignments/g-ach-parameters/

The new registry will be maintained via IETF Review as defined in RFC 5226. There are initial registrations in the new registry as follows:

Type Description Length Reference
0x00 Reserved
0x01 PW Status 20 Bytes [ RFC-to-be ]
0x02 Dual-Node Switching 16 Bytes [ RFC-to-be ]

The IANA Services Operator understands that these two 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: db3546@att.com, draft-ietf-pals-mpls-tp-dual-homing-coordination@ietf.org, pals-chairs@ietf.org, "Stewart Bryant" , pals@ietf.org, stewart.bryant@gmail.com
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP) Pseudowires Protection) to Proposed Standard


The IESG has received a request from the Pseudowire And LDP-enabled
Services WG (pals) to consider the following document:
- 'Dual-Homing Coordination for MPLS Transport Profile (MPLS-TP)
  Pseudowires Protection'
  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 2017-02-13. 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


  In some scenarios, MPLS Transport Profile (MPLS-TP) Pseudowires (PWs)
  (RFC 5921) may be statically configured (management plane based),
  when a dynamic control plane is not available.  A fast protection
  mechanism for MPLS-TP PWs is needed to protect against the failure of
  an Attachment Circuit (AC), the failure of a Provider Edge (PE), or a
  failure in the Packet Switched Network (PSN).  The framework and
  typical scenarios of dual-homing PW local protection are described in
  [draft-ietf-pals-mpls-tp-dual-homing-protection].  This document
  proposes a dual-homing coordination mechanism for MPLS-TP PWs, which
  is used for state exchange and switchover coordination between the
  dual-homing PEs for dual-homing PW local protection.





The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-pals-mpls-tp-dual-homing-coordination/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-pals-mpls-tp-dual-homing-coordination/ballot/

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

  https://datatracker.ietf.org/ipr/2534/



The document contains these normative downward references.
See RFC 3967 for additional information:
    rfc5921: A Framework for MPLS in Transport Networks (Informational - IETF stream)
Note that some of these references may already be listed in the acceptable Downref Registry.

Request for posting confirmation emailed to previous authors: "Shahram Davari" , "Alessandro D'Alessandro" , "Kai Liu" , pals-chairs@ietf.org, "Lei Wang" , "Han Li" , "Weiqiang Cheng" , "Jie Dong"

(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, which is indicated in the header.

  This text describes protocol extensions needed by the industry
  and this is the correct track.

(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

  In some scenarios, the MPLS Transport Profile (MPLS-TP) Pseudowires
  (PWs) are provisioned through either static configuration or
  management plane, where a dynamic control plane is not available.  A
  fast protection mechanism for MPLS-TP PWs is needed to protect
  against the failure of Attachment Circuit (AC), the failure of
  Provider Edge (PE) and also the failure in the Packet Switched
  Network (PSN).  The framework and typical scenarios of dual-homing PW
  local protection are described in [draft-ietf-pals-mpls-tp-dual-
  homing-protection].  This document proposes a dual-homing
  coordination mechanism for MPLS-TP PWs, which is used for state
  exchange and switchover coordination between the dual-homing PEs for
  dual-homing PW local protection.


Working Group Summary

  This was a straight-forward design process with no controvercy.

Document Quality

  Dual homed protection is important for mobile services, and the
  need for this is called out in BBF TR-221 " Technical Specifications
  for MPLS in Mobile Backhaul Networks" where it remains for
  further study.

  Please see https://www.broadband-forum.org/technical/download/TR-221.pdf
 

Personnel

  Stewart Bryant 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 completed a line by line review before WG LC. There were no
  technical comments in WGLC so I believe it is ready for AD review.

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

  I do not.

(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, the normal review process will be adequate.

(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.

  I have no 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 they have.

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

  The WG were not concerned about the IPR disclosure.

(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?

  Although the WG has not been vocal, this has been discused and I
  am happy the WG supports publication.

(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.

  There are no meaningful nits.

(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 they have.

(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 have been published. 

(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.

  There are no downrefs

(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.

  This draft does not change the status of any RFC.


(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).

  The IANA considerations look fine.

(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.

  There are none.

(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.

  No applicable to this draft.