MPLS Transport Profile (MPLS-TP) Linear Protection to Match the Operational Expectations of Synchronous Digital Hierarchy, Optical Transport Network, and Ethernet Transport Network Operators
RFC 7271

Received changes through RFC Editor sync (changed abstract to 'This document describes alternate mechanisms to perform some of the functions of MPLS Transport Profile (MPLS-TP) linear protection defined in RFC 6378, and also defines additional mechanisms. The purpose of these alternate and additional mechanisms is to provide operator control and experience that more closely models the behavior of linear protection seen in other transport networks.

This document also introduces capabilities and modes for linear protection. A capability is an individual behavior, and a mode is a particular combination of capabilities. Two modes are defined in this document: Protection State Coordination (PSC) mode and Automatic Protection Switching (APS) mode.

This document describes the behavior of the PSC protocol including priority logic and state machine when all the capabilities associated with the APS mode are enabled.

This document updates RFC 6378 in that the capability advertisement method defined here is an addition to that document.')

[Ballot comment]
OPS DIR review by Tina:

Summary: Ready with nits



Line 410, delete 1st 'when'



Line 425, replace 'Switch- over' with 'Switch-over'



Line 453, 'is accepted' can be deleted for redundancy



Line 549, replace 'transmission' with 'received' or delete it, otherwise ‘integrity of the packet transmission’ does not parse



Line 575, delete 'under SD condition' as it is redundant



Line 580-583, the phrases:

  "...The packet duplication SHALL continue in the WTR

  state in revertive operation and SHALL stop when the node leaves the

  WTR state.  In non-revertive operation, the packet duplication SHALL

  stop when the SD condition is cleared."

should be rewritten as:

  "When the SD condition is cleared, in revertive operation, the packet duplication

SHALL continue in the WTR state and SHALL stop when the node leaves the

    WTR state; while in non-revertive operation, the packet duplication SHALL stop immediately."

[Ballot comment]

I only quickly scanned this so maybe I'm totally wrong
here but isn't this spec defining new ways in which an
operator could break a network manually? If so, isn't that
a security consideration? But maybe that's covered in 6378
or 5920 or I'm just talking nonsense:-)

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-mpls-tp-psc-itu-02.  Authors should review the comments and/or questions below.  Please report any inaccuracies and respond to any questions as soon as possible.

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

First, in the MPLS PSC Request Registry of the Generic Associated Channel (G-ACh) Parameters registry located at:

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

two new PSC Request values will be registered as follows:

Value: 2
Description: Reverse Request
Reference: [ RFC-to-be ]

Value: 3
Description: Exercise
Reference [ RFC-to-be ]

Second, in the MPLS PSC TLV Registry of the Generic Associated Channel (G-ACh) Parameters registry located at:

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

a single new code point will be registered as follows:

Value: [ TBD-at-registration ]
Description: Capabilities
Reference: [ RFC-to-be ]

Third, IANA will create a new registry called the MPLS PSC Capability Flag Registry. The new registry will be a new subregistry of the Generic Associated Channel (G-ACh) Parameters registry located at:

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

The new registry will be maintained via Standards Action as defined in RFC 5226. IANA understands that the length of the flags MUST be a multiple of 4 octets. There are initial registrations in this new registry as follows:

Bit Hex Value Capability Reference
---- ---------- ----------------------------------- ---------------
0 0x80000000 priority modification [ RFC-to-be ]
1 0x40000000 non-revertive behavior modification [ RFC-to-be ]
2 0x20000000 support of MS-W command [ RFC-to-be ]
3 0x10000000 support of protection against SD [ RFC-to-be ]
4 0x08000000 support of EXER command [ RFC-to-be ]
5-31 Unassigned [ RFC-to-be ]

IANA understands that these three actions are the only ones that need 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.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (MPLS Transport Profile (MPLS-TP) Linear Protection to Match the Operational Expectations of SDH, OTN and Ethernet Transport Network Operators) to Proposed Standard

The IESG has received a request from the Multiprotocol Label Switching WG
(mpls) to consider the following document:
- 'MPLS Transport Profile (MPLS-TP) Linear Protection to Match the
  Operational Expectations of SDH, OTN and Ethernet Transport Network
  Operators'
  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 2014-02-24. 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 document describes alternate mechanisms to perform some of the
  sub-functions of MPLS Transport Profile (MPLS-TP) linear protection
  defined in RFC 6378, and also defines additional mechanisms.  The
  purpose of these alternate and additional mechanisms is to provide
  operator control and experience that more closely models the behavior
  of linear protection seen in other transport networks.

  This document also introduces capabilities and modes for linear
  protection.  A capability is an individual behavior, and a mode is a
  particular combination of capabilities.  Two modes are defined in
  this document: Protection State Coordination (PSC) mode and Automatic
  Protection Switching (APS) mode.

  This document describes the behavior of the PSC protocol including
  priority logic and state machine when all the capabilities associated
  with the APS mode are enabled.

  This document updates RFC 6378 in that the capability advertisement
  method defined here is an addition to that document.


The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-mpls-tp-psc-itu/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-mpls-tp-psc-itu/ballot/

The following IPR Declarations may be related to this I-D:
  http://datatracker.ietf.org/ipr/2306/

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.

  The MPLS working group requests that
   
    MPLS Transport Profile (MPLS-TP) Linear Protection to Match
            the Operational Expectations of SDH, OTN and
              Ethernet Transport Network Operators

                          draft-ietf-mpls-tp-psc-itu-0

  is published as an RFC on the Standards Track.

(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?

  Type of RFC: Proposed Standard.
  The Document header says "Standards Track".

  Proposed standard is the right type of RFC, since thé document
  (a) specifies protocol
  (b) updates an Standard Track RFC.

(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.

        The document describes alternate mechanisms to perform some of the
        MPLS-TP  linear protection sub-functions defined in RFC 6378. It also defines
        additional mechanisms. 
        The purpose of these mechanisms is to closely model the behavior of
        linear protection seen in other transport networks.

        This document also introduces capabilities and modes for linear protection. 
        A capability is an individual behavior, and a mode is a particular combination
        of capabilities.  Two modes are defined PSC mode and  APS mode.

      The document describes the behavior of the PSC protocol including
        when all the capabilities of the APS mode are enabled. The document
      describes priority logic and the protocol state machine.

      The document updates RFC 6378 in that the capability advertisement
      method defined here is an addition to that document.


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 document has a rather long history. It is intended to match the
      operational practices and methods that have been used by transport
      network operators prior to the introduction of MPLS. When RFC 6378 was
      progressed it was decided that backwards compatibility with deployed MPLS
      networks was the priority.

      Later the discussion on meeting the requirements from transport network
      operators re-emerged and it was decided that the solution should be based
      on RFC 6378. To that end RFC 6378 had to be slightly extended and
      modified. There were 5 capabilities missing in RFC 6378, these were the
      extensions.  There were also cases where relative priority between different
      actions need to be changed, these were the modifications.

      The first approach were to write a single document for each capability (at the
      time it was thought that the capabilities might be activated independently),
      The discussion in the working group however converged on putting all the
      capabilities in one document.

      As the first mpls-rt review and the discussion in the working clearly indicated
      a wish to make the merged document a working group document the wg
      chairs did the second mpls-rt review and took the decision to make it a
      working group document without  running the normal wg adoption poll. Instead
      evaluating the discussion on the mailing and their own review. 
.
      The document has, nevertheless been well discussed within the working group.

      After that the document became a working group document there has been a
      good and open discussion on the mailing.

      It is the Shepherds opinion that the document is ready for publication.
     

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?

      An implementation poll has been sent to the working group mailing
      list and the write-up will be updated if and when the information is available.

      There is strong indications vendor interest.

      There is a long list of important reviewers, especially the mpls-rt
      reviewers that contributed the arguments that resulted in the current document
      structure and that also did a careful technical review.

Personnel

  Who is the Document Shepherd? Who is the Responsible Area
  Director?

      Adrian Farrel is the responsible AD
      Loa Andersson is the document shepherd

(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 would like to refer to the text under section 2 above, since
      has taken part in that process.
      Full document review  has been done on the merged document as part of
      mpls-rt review and prior to and during wglc.

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

      No such concerns.

(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 such reviews necessary.

(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 such concerns.

      One thing is that we have 6 editors/authors on the first page, since the
      document is the result of merging 5 documents as well as appointing two
      editors, we believe that in this case this is justified.

(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 all authors have stated that they are unaware of any non-disclosed
      IPRs.

      Further, due to intensive reviews and discussion on text there is a
      paragraph in the Acknowledgment Section that says:

      "We would also like to acknowledge explicit text provided by Loa
        Andersson and Adrian Farrel."
        Both Loa and Adrian have stated on the list that they are unaware of any
        IPR, other then already disclosed, relevant for this document.

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

      There is one IPR disclosure against this document. This is in fact
      an older IPR that when it was once filed was believed not to relate to any
      IETF document, however when reading and reviewing draft-ietf-mpls-tp-psc-itu
      one of the reviewers realized the patent was applicable to this document. This
      was made clear to the working group during the wglc.

(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? 

        The working group is behind this document.

(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 such threats.

(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.

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

      No formal reviews required.

(13) Have all references within this document been identified as
either normative or informative?

      Yes, all the references are correctly classified.

(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 the normative references are to RFCs.

(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 downward references

(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 document will update RFC 6378, that RFC is listed at all the
      correct places. 

(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 document shepherd reviewed the IANA section in the period
      prior to the wglc.
      This document creates one new IANA registry. Suggested layout and
      allocation policies are clearly defined.

(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 no new IANA registries that require Expert Review.

(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 such reviews.