Skip to main content

Multicast Negative-Acknowledgment (NACK) Building Blocks
draft-ietf-rmt-bb-norm-revised-07

Revision differences

Document history

Date Rev. By Action
2012-08-22
07 (System) post-migration administrative database adjustment to the No Objection position for Pasi Eronen
2012-08-22
07 (System) post-migration administrative database adjustment to the No Objection position for David Ward
2012-08-22
07 (System) post-migration administrative database adjustment to the No Objection position for Tim Polk
2012-08-22
07 (System) post-migration administrative database adjustment to the No Objection position for Lars Eggert
2012-08-22
07 (System) post-migration administrative database adjustment to the No Objection position for Ronald Bonica
2008-09-24
07 (System) IANA Action state changed to No IC from In Progress
2008-09-24
07 (System) IANA Action state changed to In Progress
2008-09-23
07 Amy Vezza State Changes to RFC Ed Queue from Approved-announcement sent by Amy Vezza
2008-09-23
07 Amy Vezza IESG state changed to Approved-announcement sent
2008-09-23
07 Amy Vezza IESG has approved the document
2008-09-23
07 Amy Vezza Closed "Approve" ballot
2008-09-23
07 Amy Vezza State Changes to Approved-announcement to be sent from IESG Evaluation::AD Followup by Amy Vezza
2008-09-22
07 David Ward [Ballot Position Update] Position for David Ward has been changed to No Objection from Discuss by David Ward
2008-09-18
07 Ron Bonica [Ballot Position Update] Position for Ron Bonica has been changed to No Objection from Discuss by Ron Bonica
2008-09-15
07 Lars Eggert [Ballot Position Update] Position for Lars Eggert has been changed to No Objection from Discuss by Lars Eggert
2008-09-09
07 (System) Sub state has been changed to AD Follow up from New Id Needed
2008-09-09
07 (System) New version available: draft-ietf-rmt-bb-norm-revised-07.txt
2008-08-04
07 Magnus Westerlund State Changes to IESG Evaluation::Revised ID Needed from IESG Evaluation::AD Followup by Magnus Westerlund
2008-08-04
07 Magnus Westerlund Some discusses and comments hasn't been addressed. Awaiting new version to address them.
2008-07-22
07 Tim Polk [Ballot Position Update] Position for Tim Polk has been changed to No Objection from Undefined by Tim Polk
2008-07-22
07 Tim Polk [Ballot Position Update] Position for Tim Polk has been changed to Undefined from Discuss by Tim Polk
2008-07-17
07 Pasi Eronen [Ballot Position Update] Position for Pasi Eronen has been changed to No Objection from Undefined by Pasi Eronen
2008-07-17
07 Pasi Eronen [Ballot Position Update] Position for Pasi Eronen has been changed to Undefined from Discuss by Pasi Eronen
2008-07-14
07 (System) Sub state has been changed to AD Follow up from New Id Needed
2008-07-14
06 (System) New version available: draft-ietf-rmt-bb-norm-revised-06.txt
2008-07-08
07 David Ward
[Ballot discuss]
Here are some suggestions and issues:

a) Section 4 refers to ASM service model (RFC1112) and
  then to SSM as …
[Ballot discuss]
Here are some suggestions and issues:

a) Section 4 refers to ASM service model (RFC1112) and
  then to SSM as "Single-Source-Multicast" with reference
  as Hughs Diss. Also section 2.6 refers to SSM this way.

  These terms and references for SSM should be changed to
  "Source Specific Multicast" and reference RFC4607. Those
  are the right terms and the RFC1112 (ASM) equivalent
  definition of SSM.

b) I suggest including an appendix section highlighting the
  functional and value proposition differences between this
  NAK building block and the equivalent found in PGM.

  There is some discussion in NORM (RFC3940) in section
  5.5.2 about this, which is difficult to grok, butIi
  think it would belong (in better wording) into this
  NAK building block.

c)  I'd like  the authors to add
  a discussion about the applicability of network based NAK
  implosion and/or local retransmitter based optimizations
  to this building block, and whether or not it would be
  possible to do this such that it can be added as an
  afterthought into deployments without changes to senders
  and/or receivers to better scale them upon increase of
  topology and/or group-size.

  It's not clear to me how to best have this highlighted,
  because this is just the building block and not the full
  protocol, so one might argue that this is a NORM issue,
  not a NAK building block issue, but it also seems quite
  impossible to me to resolve this issue without impacting the
  NAK building block. For example, section 4 paragraph 2
  of this draft talks about scalability limitation of NAK
  approaches, but all of this is only true when you do
  assume no network based optimization of retransmission.
2008-07-08
07 David Ward [Ballot Position Update] New position, Discuss, has been recorded by David Ward
2008-07-04
07 (System) Removed from agenda for telechat - 2008-07-03
2008-07-03
07 Cindy Morgan State Changes to IESG Evaluation::Revised ID Needed from IESG Evaluation by Cindy Morgan
2008-07-03
07 Ross Callon
[Ballot comment]
I just have a few minor comments that the authors can address or not at their discretion. Having once long ago looked at …
[Ballot comment]
I just have a few minor comments that the authors can address or not at their discretion. Having once long ago looked at a few reliable multicast protocols I had noticed that reliable multicast is in fact a family of loosely related problems rather than one problem, and I am quite pleased that this document recognizes and clarifies this, and is focused on an approach that supports multiple related solutions.

Questions: 

Does this document obsolete RFC3941? If so it should say so.

Minor:

I think that you should say a bit more about what to do when one receiver, or a few receivers, are suffering from either much slower or much less reliable service than other receivers. One option would be to slow down the entire group. Another option would be to remove the receiver from the group, and either serve it in a different group, or not serve it at all. Is there some threshold below which a receiver should be cut out of the group (since it would be harming service to everyone else)? Is this so obvious that it doesn't need to be discussed?

Minor Editorial:

In section 1, the following sentence is at best awkward, and is probably not grammatically quite right:

  Here the protocol mechanism for reliability is described as a "repair
  process" since the use of packet-based Forward Error Correction (FEC)
  erasure coding for recovery of missing packets as compared to
  classical re-transmission schemes.

I have two questions regarding this sentence. One issue is that my understanding of FEC is that it can be used to substantially reduce the probability of error. However, it can't completely eliminate any chance of error. Also, the document otherwise talks about NAKs, suggesting that there will be cases where receivers have figured out that they are missing something (and something like "classic retransmission" may be needed). Thus on the one hand I can't figure out what this sentence is intending to say (and my second problem is that whatever it is trying to say, I don't think that it does).


In reading section 2 (top of page 5) there is the mention of bulk transfer. At this point I was wondering whether this referred to a known fixed length bulk transfer (in the case that one receiver among a great many miss a few packets, this would allow reliable multicast by transmitting the whole thing once and then going back and retransmitting parts that someone missed) versus indefinite length bulk transfer (which needs a different solution). About 20 pages later I found the correct answer in section 3.5 on page 25 (which is that both need to be supported). I am wondering if there should be a very brief forward reference on page 5 (although a reader might assume that they need to read on if they have such questions early in the document).
2008-07-03
07 Jari Arkko [Ballot Position Update] New position, No Objection, has been recorded by Jari Arkko
2008-07-03
07 Tim Polk
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to …
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to security that
  can be used to address these and other security considerations.

This needs to be a MUST.  I would expect (current or future) security ADs to block progression
of reliable muticast protocols that did *not* address these considerations, so let's be clear
about the requirement up front.  (Given that the remainder of this section provides a number
of hints about using an IPsec-based approach, this isn't too much of a burden on the protocol
developer anyway.)
2008-07-03
07 Tim Polk
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to …
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to security that
  can be used to address these and other security considerations.

This needs to be a MUST.  I doubt current or future security ADs would progression of
reliable muticast protocols that did *not* address these considerations!  (Given that the
remainder of this section provides a number of hints about using an IPsec-based
approach, this isn't too much of a burden on the protocol developer.)
2008-07-03
07 Tim Polk [Ballot comment]
Security Considerations, second paragraph:

s/appropriate extend IPsec mechanisms/extend appropriate IPsec mechanisms/
2008-07-03
07 Tim Polk
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to …
[Ballot discuss]
The first paragraph of the security considerations ends with the following sentence:

Protocol instantiations
  using this building block SHOULD identify approaches to security that
  can be used to address these and other security considerations.

This needs to be a MUST.  (Given that the remainder of this section provides a number of
hints about using an IPsec-based approach, this isn't too much of a burden on the protocol
developer.)
2008-07-03
07 Tim Polk [Ballot Position Update] New position, Discuss, has been recorded by Tim Polk
2008-07-03
07 Dan Romascanu [Ballot Position Update] New position, No Objection, has been recorded by Dan Romascanu
2008-07-03
07 Pasi Eronen [Ballot comment]
In the acknowledgements section, I suspect that the comma in "George,
Gross" is a typo.
2008-07-03
07 Pasi Eronen
[Ballot discuss]
Concerns from Rob Austein's SecDir review:

- The Security Considerations recommend use of authentication and
  encryption.  Authentication is good, but I'd expect …
[Ballot discuss]
Concerns from Rob Austein's SecDir review:

- The Security Considerations recommend use of authentication and
  encryption.  Authentication is good, but I'd expect this to tie into
  the (very brief) "Reliable Multicast Member Identification" section
  (3.4).  A bit more discussion in the main text might be in order,
  particularly since, as the Security Considerations already mention,
  a participant in protocols based on this building block can
  misbehave in ways that hurt other participants.

(In particular, if member identification is done inside the
actual content, and cryptographic authentication is provided by
IPsec (which doesn't inspect the content, only the headers),
there's clearly room for participants to send different information
in these two layers.)

- "Encryption" is not a security service, it's a technique for
  providing certain security services.  It's better to be specific
  about the security services these protocols need: confidentiality?
  data integrity?  and, in each case, why?  Don't tell me, put it in
  the Security Considerations.

(I agree, it's not clear how encryption is relevant to the discussion
in that paragraph; authentication and data integrity certainly are.)

- I couldn't quite figure out what the authors meant by "a digital
  signature on the IPsec Encapsulating Security Protocol (ESP)
  payload".  I could guess, but that's not the point.  This should be
  rephrased or clarified.

(Maybe reference to RFC4359?)
2008-07-03
07 Pasi Eronen [Ballot Position Update] New position, Discuss, has been recorded by Pasi Eronen
2008-07-03
07 Jon Peterson [Ballot Position Update] New position, No Objection, has been recorded by Jon Peterson
2008-07-02
07 Ross Callon [Ballot Position Update] New position, No Objection, has been recorded by Ross Callon
2008-07-02
07 Cullen Jennings [Ballot Position Update] New position, No Objection, has been recorded by Cullen Jennings
2008-07-02
07 Lisa Dusseault [Ballot Position Update] New position, No Objection, has been recorded by Lisa Dusseault
2008-07-02
07 Ron Bonica
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed …
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed that use shared, common keys for
  receiver-originated protocol messages to maintain a practical number
  of IPsec Security Associations (SAs).  However, such group-based
  authentication may not be sufficient unless the receiver population
  can be completely trusted.  Additionally, this can make
  identification of badly-behaving (although authenticated) receiver
  nodes problematic as such nodes could potentially masquerade as other
  receivers in the group.  In deployments such as this, one SHOULD
  consider use of Specific-Source Multicast (SSM) instead of Any-Source
  Multicast (ASM) models of multicast operation.

I don't see how SSM will help. AFAIKS, SSM reduces the number of senders, but the one sender still has a big problem to solve.

You continue:

  SSM can simplify
  security challenges with senders providing a centralized management
  point for secure group operation.  When individual host
  authentication is required, then it is possible receivers could use a
  digital signature on the IPsec Encapsulating Security Protocol (ESP)
  payload.  Either an identity-based signature system or a group-
  specific public key infrastructure could avoid per-receiver state at
  the sender(s). Additionally, implementations MAY also support
  policies to limit the impact of extremely or exceptionally poor-
  performing (due to bad behavior or otherwise) receivers upon overall
  group operation if this acceptable for the relevant application.

I thnk that the last MAY should be a MUST. Otherwise, one poor performer could severely impact everybody.


Also, it is not clear to me how you react when N parties fall behind because they are bandwidth constrained. Does the sender slow down or ingnore NAKs from bandwidth constrained receivers.
2008-07-02
07 Ron Bonica
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed …
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed that use shared, common keys for
  receiver-originated protocol messages to maintain a practical number
  of IPsec Security Associations (SAs).  However, such group-based
  authentication may not be sufficient unless the receiver population
  can be completely trusted.  Additionally, this can make
  identification of badly-behaving (although authenticated) receiver
  nodes problematic as such nodes could potentially masquerade as other
  receivers in the group.  In deployments such as this, one SHOULD
  consider use of Specific-Source Multicast (SSM) instead of Any-Source
  Multicast (ASM) models of multicast operation.

I don't see how SSM will help. AFAIKS, SSM reduces the number of senders, but the one sender still has a big problem to solve.

You continue:

  SSM can simplify
  security challenges with senders providing a centralized management
  point for secure group operation.  When individual host
  authentication is required, then it is possible receivers could use a
  digital signature on the IPsec Encapsulating Security Protocol (ESP)
  payload.  Either an identity-based signature system or a group-
  specific public key infrastructure could avoid per-receiver state at
  the sender(s). Additionally, implementations MAY also support
  policies to limit the impact of extremely or exceptionally poor-
  performing (due to bad behavior or otherwise) receivers upon overall
  group operation if this acceptable for the relevant application.

I thnk that the last MAY should be a MUST. Otherwise, one poor performer could severely impact everybody.
2008-07-02
07 Ron Bonica
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed …
[Ballot discuss]
In the security consideration section you say:

  For NACK-based multicast deployments with large receiver groups using
  IPsec, approaches might be developed that use shared, common keys for
  receiver-originated protocol messages to maintain a practical number
  of IPsec Security Associations (SAs).  However, such group-based
  authentication may not be sufficient unless the receiver population
  can be completely trusted.  Additionally, this can make
  identification of badly-behaving (although authenticated) receiver
  nodes problematic as such nodes could potentially masquerade as other
  receivers in the group.  In deployments such as this, one SHOULD
  consider use of Specific-Source Multicast (SSM) instead of Any-Source
  Multicast (ASM) models of multicast operation.

I don't see how SSM will help. AFAIKS, SSM reduces the number of senders, but the one sender still has a big problem to solve.

You continue:

  SSM can simplify
  security challenges with senders providing a centralized management
  point for secure group operation.  When individual host
  authentication is required, then it is possible receivers could use a
  digital signature on the IPsec Encapsulating Security Protocol (ESP)
  payload.  Either an identity-based signature system or a group-
  specific public key infrastructure could avoid per-receiver state at
  the sender(s). Additionally, implementations MAY also support
  policies to limit the impact of extremely or exceptionally poor-
  performing (due to bad behavior or otherwise) receivers upon overall
  group operation if this acceptable for the relevant application.

I thnk that the last MAY should be a MUST. Otherwise, one poor performer could severely impact everybody.
2008-07-02
07 Ron Bonica [Ballot Position Update] New position, Discuss, has been recorded by Ron Bonica
2008-06-30
07 Chris Newman [Ballot Position Update] New position, No Objection, has been recorded by Chris Newman
2008-06-30
07 Lars Eggert
[Ballot comment]
>    This
>    document is a product of the IETF RMT WG and follows the guidelines
>    provided in [ …
[Ballot comment]
>    This
>    document is a product of the IETF RMT WG and follows the guidelines
>    provided in [RFC3269].

  Suggest to remove the reference to the RMT WG for the published RFC.
2008-06-30
07 Lars Eggert
[Ballot discuss]
Section 3., paragraph 3:
>    This memo contains descriptions of building blocks that can be
>    applied in the design of …
[Ballot discuss]
Section 3., paragraph 3:
>    This memo contains descriptions of building blocks that can be
>    applied in the design of Reliable Multicast protocols utilizing
>    Negative-Acknowledgement (NACK) feedback.  [RFC3941] contained a
>    previous description of this specification.  RFC3941 was published in
>    the "Experimental" category.  It was the stated intent of the RMT
>    working group to re-submit this specifications as an IETF Proposed
>    Standard in due course.

  DISCUSS: This draft obsoletes RFC3941. Need to state this in the
  first-page header and the abstract.
2008-06-30
07 Lars Eggert [Ballot Position Update] New position, Discuss, has been recorded by Lars Eggert
2008-06-25
07 Magnus Westerlund Placed on agenda for telechat - 2008-07-03 by Magnus Westerlund
2008-06-24
07 Magnus Westerlund State Changes to IESG Evaluation from Waiting for AD Go-Ahead::AD Followup by Magnus Westerlund
2008-06-24
07 Magnus Westerlund [Ballot Position Update] New position, Yes, has been recorded for Magnus Westerlund
2008-06-24
07 Magnus Westerlund Ballot has been issued by Magnus Westerlund
2008-06-24
07 Magnus Westerlund Created "Approve" ballot
2008-05-30
07 (System) Sub state has been changed to AD Follow up from New Id Needed
2008-05-30
05 (System) New version available: draft-ietf-rmt-bb-norm-revised-05.txt
2008-04-18
07 Magnus Westerlund State Changes to Waiting for AD Go-Ahead::Revised ID Needed from Waiting for AD Go-Ahead by Magnus Westerlund
2008-04-17
07 (System) State has been changed to Waiting for AD Go-Ahead from In Last Call by system
2008-04-15
07 Amanda Baber IANA Last Call comments:

As described in the IANA Considerations section, we understand
this document to have NO IANA Actions.
2008-04-03
07 Samuel Weiler Request for Last Call review by SECDIR is assigned to Rob Austein
2008-04-03
07 Samuel Weiler Request for Last Call review by SECDIR is assigned to Rob Austein
2008-04-03
07 Amy Vezza Last call sent
2008-04-03
07 Amy Vezza State Changes to In Last Call from Last Call Requested by Amy Vezza
2008-04-02
07 Magnus Westerlund Last Call was requested by Magnus Westerlund
2008-04-02
07 Magnus Westerlund State Changes to Last Call Requested from AD Evaluation::AD Followup by Magnus Westerlund
2008-04-02
07 (System) Ballot writeup text was added
2008-04-02
07 (System) Last call text was added
2008-04-02
07 (System) Ballot approval text was added
2008-04-02
07 (System) Sub state has been changed to AD Follow up from New Id Needed
2008-04-02
04 (System) New version available: draft-ietf-rmt-bb-norm-revised-04.txt
2008-03-19
07 Magnus Westerlund State Changes to AD Evaluation::Revised ID Needed from AD Evaluation by Magnus Westerlund
2008-03-17
07 Magnus Westerlund State Changes to AD Evaluation from Publication Requested by Magnus Westerlund
2008-02-20
07 Magnus Westerlund State Changes to Publication Requested from AD is watching by Magnus Westerlund
2008-02-19
07 Cindy Morgan
Document Shepherd Write-Up for draft-ietf-rmt-bb-norm-revised-03
intended for publication in the "Proposed Standard" category.

This writeup complies with RFC 4858


    (1.a)  Who is the …
Document Shepherd Write-Up for draft-ietf-rmt-bb-norm-revised-03
intended for publication in the "Proposed Standard" category.

This writeup complies with RFC 4858


    (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?

Document Shepherd is Lorenzo Vicisano, who has personally
reviewed this version of the document and believes it is ready
for forwarding 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 document had adequate review both key WG members.

The document has been reviewed by multiple WG members and has been
updated to reflect their comments.  There are no unresolved issues.
The Experimental RFC3941 upon which this revision is based was
thoroughly reviewed.  The differences between this revision and the
original document are not substantial.

    (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 additional reviews needed.

    (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.

No concerns.

    (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?

This document represent a solid consensus of the RMT WG.

    (1.f)  Has anyone threatened an appeal or otherwise indicated extreme
          discontent?  If so, please summarize 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 discontent of significant concern have been raised about this
document.

    (1.g)  Has the Document Shepherd personally verified that the
          document satisfies all ID nits?  (See
          http://www.ietf.org/ID-Checklist.html 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?  If the document
          does not already indicate its intended status at the top of
          the first page, please indicate the intended status here.

The Document Shepherd has personally verified that the document
satisfies all ID nits.

draft-ietf-rmt-bb-norm-revised-03 is intended for publication in the
"Proposed Standard" category.

    (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].

The document splits its references into normative and
informative. The normative reference are in RFC published status.
None of the normative reference is a downward reference.

    (1.i)  Has the Document Shepherd verified that the document's IANA
          Considerations 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 [RFC2434].  If the
          document describes an Expert Review process, has the Document
          Shepherd conferred with the Responsible Area Director so that
          the IESG can appoint the needed Expert during IESG Evaluation?

The IANA consideration section exists. It states that this document
does not have any IANA dependency.

    (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?

The documents contains no section written in 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
              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.

          Working Group Summary
              Was there anything in the WG process that is worth noting?
              For example, was there controversy about particular points
              or were there decisions where the consensus was
              particularly rough?

          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?

          Personnel
              Who is the Document Shepherd for this document?  Who is the
              Responsible Area Director?  If the document requires IANA
              experts(s), insert 'The IANA Expert(s) for the registries
              in this document are .'

Document Announcement Write-Up for draft-ietf-rmt-bb-norm-revised-03 follows.

Technical Summary

    This document is an RMT Building Block that specifies data and procedures
    useful for building a reliable multicast transport protocol based
    on negative-acknowledgment (NACK) feedback.

    draft-ietf-rmt-bb-norm-revised-03 specifically defines the following
    main components for use in protocol instantiations:

      1)  Multicast sender transmission strategies
      2)  NACK repair process with timer-based feedback suppression
      3)  Round-trip timing for adapting NACK and other timers

    draft-ietf-rmt-bb-norm-revised-03 also includes context information
    defining the intended usage and applicability of the NACK building
    Block, in compliance with RFC 3269.

    Another RMT WG document, draft-ietf-rmt-pi-norm-revised, uses the
    specifications in this document to fully-define a NACK based
    reliable multicast transport protocol.

Working Group Summary

    There is consensus in the WG to publish this documents.

Document Quality

    The NORM Protocol Specification (RFC3940 and revised draft) is
    based upon the techniques described in this "building block" document.
    A public domain, open source implementation of the NORM protocol is
    available for use from the U.S. Naval Research Laboratory.  This
    implementation has been widely used in a number of applications,
    including military and commercial systems.  The INRIA has an
    implementation in progress.

    The content of this document was already reviewed and approved for
    publication as experimental RFC 3941. This document contains minor
    technical modifications.

Personnel

    Lorenzo Vicisano is the Document Shepherd.
    Magnus Westerlund is the Responsible Area Director.
2008-01-29
07 (System) State Changes to AD is watching from Dead by system
2008-01-28
03 (System) New version available: draft-ietf-rmt-bb-norm-revised-03.txt
2007-03-31
07 (System) State Changes to Dead from AD is watching by system
2007-03-31
07 (System) Document has expired
2006-09-28
07 (System) State Changes to AD is watching from Dead by system
2006-09-27
02 (System) New version available: draft-ietf-rmt-bb-norm-revised-02.txt
2006-09-11
07 (System) State Changes to Dead from AD is watching by system
2006-09-11
07 (System) Document has expired
2006-04-03
07 Magnus Westerlund Shepherding AD has been changed to Magnus Westerlund from Allison Mankin
2006-03-10
01 (System) New version available: draft-ietf-rmt-bb-norm-revised-01.txt
2006-03-04
07 Allison Mankin Draft Added by Allison Mankin in state AD is watching
2005-10-17
00 (System) New version available: draft-ietf-rmt-bb-norm-revised-00.txt