Requirements for Operations, Administration, and Maintenance (OAM) in MPLS Transport Networks
draft-ietf-mpls-tp-oam-requirements-06

[Ballot discuss]
1. I am missing loopback and remote loopback from the list of functional requirements

2. There is no mention or reference to the requirements for activating, disactivating, or monitoring OAM functionality from management interfaces

[Ballot comment]
I support Tim's DISCUSS about the need to include a more detailed discussion about the authentication, authorization, and confidentiality requirements in the Security Considerations section.

[Ballot discuss]
1. I am missing loopback and remote loopback from the list of functional requirements

2. There is no mention or reference to the requirements for activating, disactivating, or monitoring OAM functionality from management interfaces

[Ballot comment]
I support Ron's DISCUSS about forwarding OAM in non-IP environments and Tim's DISCUSS about the need to include a more detailed discussion about the authentication, authorization, and confidentiality requirements in the Security Considerations section.

[Ballot discuss]
1. I am missing loopback and remote loopback from the list of functional requirements

2. There is no mention or reference to the requirements for activating, disactivating, or monitoring OAM functionality from management interfaces

[Ballot discuss]
This is a discuss-discuss; I will clear on the call after discussion.

Is there a reason that the authentication, authorization, and confidentiality were not specified
as OAM requirements?  I would think that these mechanisms could be "MUST implement,
SHOULD use".

Currently, there is only text in the security considerations, and that text is fairly weak:
"suggests having some form of authentication, authorization, and encryption"; "mechanisms
SHOULD be provided"; and "messages MAY be authenticated".

[Ballot comment]
Section 2.2.12., paragraph 1:
>    The MPLS-TP OAM toolset MUST provide a function to enable the
>    quantification of the one-way, and if appropriate, the two-way, delay
>    of a PW, LSP or Section.

  Both the IETF and the ITU-T have detailed delay metrics, and they are
  even aligned between the two bodies [RFC2679][RFC2681]. Should we
  refer to these here?


Section 3., paragraph 1:
>    A mechanism (e.g., rate limiting) MUST be provided to prevent OAM
>    packets from causing congestion in the Packet Switched Network.

  Rate limiting only works in conjunciton with reserved PSN capacity for
  OAM (limit the rate to at most the reserved capacity.)


Section 2.1.1., paragraph 1:
>    point associated bidirectional LSPs, point-to-point undirectional

  Nit: s/undirectional/unidirectional/

[Ballot discuss]
Section 2.2.11., paragraph 2:
>    Note that packet loss ratio is the ratio of the user packets not
>    delivered to the total number of user packets transmitted during a
>    defined time interval.  The number of user packets not delivered is
>    the difference between the number of user packets transmitted by an
>    End Point and the number of user packets received at an End Point.

  DISCUSS: Both the IETF and the ITU-T have detailed packet loss
  metrics, and they are even aligned between the two bodies [RFC2680]. I
  don't think this document should in passing come up with its own
  definitions here.

[Ballot discuss]
In Section  2.1.3 you say:

The OAM functionality may be deployed in various environments.

  o  In some environments (e.g., IP/MPLS environments), IP routing and
      forwarding capabilities are inherently present in the data plane.

  o  In some environments (e.g., MPLS-TP environments), IP routing and
      forwarding capabilities may not necessarily be present in the data
      plane.

The second bullet point is problematic. If solutions MAY be deployed in non-IP environments, they MUST NOT rely on IP. This is a very strange position to take in the IETF.

Also, in Section 2.2.12, you say:

The MPLS-TP OAM toolset MUST provide a function to enable the
  quantification of the one-way, and if appropriate, the two-way, delay
  of a PW, LSP or Section.

  o  One-way delay is the time elapsed from the start of transmission
      of the first bit of a packet by an End Point until the reception
      of the last bit of that packet by the other End Point.

It may be very difficult to measure one-way delay without very well-synchronized clocks.

[Note]: 'Loa Andersson (loa@pi.nu) is the document shepherd.
Note that this document is a requirement document, for reasons that have
to do with referencibility by ITU-T we have opted to put it on the standards track. The same decision applies to all MPLS-TP requirement
documents.' added by Adrian Farrel

The MPLS WG requests that:
  Requirements for OAM in MPLS Transport Networks
  http://tools.ietf.org/html/draft-ietf-mpls-tp-oam-requirements-03
is published as an RFC on the standards track.

Note that this document is a requirement document. For reasons that
have to do with how the ITU-T can reference RFCs we have opted to put
it on the Standards Track.

> (1.a) Who is the Document Shepherd for this document? Has the
>      Document Shepherd personally reviewed this version of the
>      document and, in particular, does he or she believe this
>      version is ready for forwarding to the IESG for publication?

Loa Andersson is the Document Shepherd.
He has reviewed the codument and believes it is ready to be
forwarded to the IESG for publication.

> (1.b) Has the document had adequate review both from key WG members
>      and from key non-WG members? Does the Document Shepherd have
>      any concerns about the depth or breadth of the reviews that
>      have been performed?

The review has been substantial.
Considerable input to early revisions was received from MPLS WG
participants and from a detailed review by members of ITU-T Study
Group 15.

The WG last call was liaised to the ITU-T and received a number of
comments that were addressed in the final revision that was supported
by the ITU-T in a liaison.

The WG last call was notified to the PWE3 and CCAMP working groups.

> (1.c) Does the Document Shepherd have concerns that the document
>      needs more review from a particular or broader perspective,
>      e.g., security, operational complexity, someone familiar with
>      AAA, internationalization or XML?

No. The document includes details of MPLS-TP OAM features, but
was authored and reviewed by many people active in the Operations Area.

> (1.d) Does the Document Shepherd have any specific concerns or
>      issues 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. Has an IPR disclosure related to this document
>      been filed? If so, please include a reference to the
>      disclosure and summarize the WG discussion and conclusion on
>      this issue.

An issue was raised on the IETF mailing list and during review by the
ITU-T Study Group 15 that caused a lot of discussion. The issue was
whether or not there is a requirement for interworking or translation
between MPLS-TP OAM and Ethernet OAM as described in the ITU=T
Recommendation Y.1731.

The IESG was consulted and ruled that this topic is currently out of
scope for the MPLS-TP effort within the IETF. Although this was a
sufficient resolution in the IETF (where there was already rough
consensus not to include this requirement), the ITU-T continued to
debate the requirement. As of the time at which the ITU-T notified us
that they support the publication of the I-D as an RFC, Study Group 15
had not managed to reach consensus on the details of this requirement.
They have agreed that, if they reach consensus and want to include the
requirement, they will bring it to the IETF using the MPLS Change
Process (RFC 4929).

Please note that the acronym "OAM" is expanded in line with draft-ietf-
opsawg-mpls-tp-oam-def.


> (1.e) 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?

Development of the document was performed within the MPLS-TP design
team (c. 20 people) that strongly supports the work. There has also
been discussion on the MPLS-TP (open) mailing list, and there
were no objections raised.

There are still some people within the IETF who believe that we
should include the requirements for OAM interworking, however, the
consensus to not include them is reasonably strong.

> (1.f) 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
>      entered into the ID Tracker.)

No threats or extreme discontent.

> (1.g) Has the Document Shepherd personally verified that the
>      document satisfies all ID nits? (See the Internet-Drafts Checklist
>      and http://tools.ietf.org/tools/idnits/). Boilerplate checks are
>      not enough; this check needs to be thorough. Has the document
>      met all formal review criteria it needs to, such as the MIB
>      Doctor, media type and URI type reviews?

All checks are clean.

> (1.h) Has the document split its references into normative and
>      informative? 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
>      strategy for their completion? Are there normative references
>      that are downward references, as described in [RFC3967]? If
>      so, list these downward references to support the Area
>      Director in the Last Call procedure for them [RFC3967].

References are correctly split.

The is an informative reference to draft-ietf-mpls-tp-framework-03
this has currently a highe revision, but it still work in progress
and will be further updated.

> (1.i) Has the Document Shepherd verified that the document IANA
>      consideration section exists and is consistent with the body
>      of the document? If the document specifies protocol
>      extensions, are reservations requested in appropriate IANA
>      registries? Are the IANA registries clearly identified? If
>      the document creates a new registry, does it define the
>      proposed initial contents of the registry and an allocation
>      procedure for future registrations? Does it suggest a
>      reasonable name for the new registry? See [RFC5226]. If the
>      document describes an Expert Review process has Shepherd
>      conferred with the Responsible Area Director so that the IESG
>      can appoint the needed Expert during the IESG Evaluation?

There are no IANA actions associated with this document.

A null IANA section is present.

> (1.j) Has the Document Shepherd verified that sections of the
>      document that are written in a formal language, such as XML
>      code, BNF rules, MIB definitions, etc., validate correctly in
>      an automated checker?

No such formal language.

> (1.k) 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

  This document lists architectural and functional requirements for the
  Operations, Administration and Maintenance of the MPLS Transport
  Profile. These requirements apply to pseudowires, Label Switched
  Paths, and MPLS-TP Sections.

Working Group Summary

  The document is part of the MPLS-TP project, the cooperation
  between IETF and ITU-T to specify an MPLS transport profile.
  The working group has consensus on the document, and the ITU-T
  has indicated that it supports the publication

  The ITU-T has one outstanding issue on which they could not reach
  consensus: there will a continued discussion on the requirements
  for OAM interworking/translation, and further requirements may be
  subsequently brought to the IETF in a new I-D.

  The document has been put on the standards track to resolve issues
  around how the ITU-T references IETF documents.

Document Quality

  The document is a requirements specification and will mainly
  be used as input to the OAM solutions specifications that will be
  published shortly.