Multicast Mobility Routing Optimizations for Proxy Mobile IPv6
draft-ietf-multimob-pmipv6-ropt-08

[Ballot comment]

Apologies, I didn't have time to really review this but I
don't get how you can change the multicast anchor and
routing and yet introduce no new security considerations.

The secdir review [1] raised some similar questions to
which the authors responded with some suggested changes
that I assume will be made in -08.

  [1] http://www.ietf.org/mail-archive/web/secdir/current/msg04128.html

One note: in the answer to the secdir review, the author
said: "The addition of the new option does not address any
security issue as long as the signaling is properly secured
reusing Proxy Mobile IPv6 mechanisms." That could be a
misinterpretation of what this section is meant to contain.
If so, I'd suggest taking a read of BCP 72 [2] which says
that you should document the security considerations of
this protocol and not just the new security features it
introduces. Or maybe the quoted text is just a slightly
loose email, which is quite understandable.

  [2] http://tools.ietf.org/html/bcp72

Lastly, that's a lot of complicated IPR declarations. I'd
not be surprised if those disincentivise implementers. It'd
put me off for example. But I guess the wg had consensus
that it's ok with that.

[Ballot comment]
I am balloting Yes on this document on the strength of reviews by
the PIM WG.  I would be glad if you looked at my comments below.

====

Thank you for recognising that this work is best brought forward as
Experimental. I should like it if the Abstract made the point that this
is intended as an Experiment. I think it important to add some text to
the Introduction to:
- state that this work is Experimental
- describe the scope of the experiment and how it is contained
- explain what happens if any of this experiment interacts with the
  wider Internet
- indicate what people should experiment with, what they should report
  back, how the experiment will be judged, and what the next steps might
  be.

---

The RFC Editor will ask you to remove the citation from the Abstract.

---

Section 2
                               
  In this draft we refine such definition from the point of view of the

s/draft/document/
                               
---

Section 5.1.2

Maybe the explanatory text should be ordered the same as in the message
option?

---

Section 5.1.2

The description of "Dynamic IP Multicast Selector Mode Flag" uses
"SHOULD" for behaviors of 1 and 0. That implies that there is an option
to do something different. Can you describe the circumstances where an
implementation MAY do something else.

---

Section 9 should really identify the registry from which the allocation
is to be made per Barry's comment.

[Ballot comment]
I am deferring this document to the next telechat so that I can get
review and input from the PIM working group. That working group has
responsiblity for MLD and IGMP, and more generally for multicast
routing.

Sorry that this will slow the document down a little. I should have
spotted the issue sooner, but missed it during IETF last call.

Meanwhile, here are my own review comments. I am likely to ballot
No Objection unless the PIM WG comes up with major issues.

====

Thank you for recognising that this work is best brought forward as
Experimental. I should like it if the Abstract made the point that this
is intended as an Experiment. I think it important to add some text to
the Introduction to:
- state that this work is Experimental
- describe the scope of the experiment and how it is contained
- explain what happens if any of this experiment interacts with the
  wider Internet
- indicate what people should experiment with, what they should report
  back, how the experiment will be judged, and what the next steps might
  be.

---

The RFC Editor will ask you to remove the citation from the Abstract.

---

Section 2
                               
  In this draft we refine such definition from the point of view of the

s/draft/document/
                               
---

Section 5.1.2

Maybe the explanatory text should be ordered the same as in the message
option?

---

Section 5.1.2

The description of "Dynamic IP Multicast Selector Mode Flag" uses
"SHOULD" for behaviors of 1 and 0. That implies that there is an option
to do something different. Can you describe the circumstances where an
implementation MAY do something else.

---

Section 9 should really identify the registry from which the allocation
is to be made per Barry's comment.

[Ballot comment]
I've just one quibble with the document: the IANA Considerations do not properly specify what needs to be done -- the registry isn't mentioned at all.  This is *not* a DISCUSS, because IANA have figured out what to do.  That said, it wouldn't hurt to make it clear in the document, so that others reading it will know what registry is involved:

OLD
  This document defines a new mobility option, the Dynamic IP Multicast
  Selector, which has been assigned the type TBD by IANA.
NEW
  This document defines a new mobility option, the Dynamic IP Multicast
  Selector (see Section 5.1).  IANA has assigned this option the type TBD
  and has registered it in the Mobility Options subregistry of the Mobile IPv6
  Parameters registry.
  [RFC Editor: Please replace "TBD" above with the value assigned by IANA.]
END

Oh, and I think our custom is to name Section 11 as "Contributors", not "Authors".  The RFC Editor will sort that out, I suppose.

IESG/Authors/WG Chairs:

IANA has reviewed draft-ietf-multimob-pmipv6-ropt-06.  Authors should review the comments and/or questions below.  Please report any inaccuracies and respond to any questions as soon as possible.

We understand that, upon approval of this document, there is a single action which we must complete.

In the Mobility Options subregistry of the Mobile IPv6 Parameters registry located at:

http://www.iana.org/assignments/mobility-parameters/mobility-parameters.xml

a single, new Mobility Option will be registered as follows:

Value: [ TBD-at-registration ]
Description: Dynamic IP Multicast Selector
Reference: [ RFC-to-be ]

We understand this to be the only action 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.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Multicast Mobility Routing Optimizations for Proxy Mobile IPv6) to Informational RFC


The IESG has received a request from the Multicast Mobility WG (multimob)
to consider the following document:
- 'Multicast Mobility Routing Optimizations for Proxy Mobile IPv6'
  as Informational RFC

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 2013-07-03. 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 base solution to support IP multicasting in a PMIPv6 domain is
  specified in [RFC6224].  In this document, some enhancements to the
  base solution are described.  These enhancements include the use of a
  multicast tree mobility anchor as the topological anchor point for
  multicast traffic, as well as a direct routing option where the MAG
  can provide access to multicast content in the local network.  These
  enhancements provide benefits such as reducing multicast traffic
  replication and supporting different PMIPv6 deployment scenarios.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-multimob-pmipv6-ropt/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-multimob-pmipv6-ropt/ballot/


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

  http://datatracker.ietf.org/ipr/2075/
  http://datatracker.ietf.org/ipr/2074/
  http://datatracker.ietf.org/ipr/1723/
  http://datatracker.ietf.org/ipr/2077/

All,
    Here is my AD evaluation of draft-ietf-multimob-pmipv6-ropt.  Once these issues are resolved, the draft can move to the next step in the publication process (IETF Last Call).

* There are several explicit mentions of the Multimob WG in the document.  Those sentences should be re-worded to focus on the content of the draft, rather than who created the draft.

* In the Intro : s/so-called tunnel convergence/tunnel convergence/

* Is the MTMA really just a variant of an LMA (i.e., LMA handling all multicast traffic)?  If so, the definition should clarify that.

* In 3.1 : s/is used used to/is used to/

* In 3.2, there is a reference to Figure 1 that I believe should be a reference to Figure 2.

* In 3.2, what is meant by a "direct connection" between the MAG and a multicast router?  Are they supposed to be on a shared link?  Traffic is routable between the two?  Additionally, why is that connectivity restricted from running over a tunnel?  Could they be connected via AMT (draft-ietf-mboned-auto-multicast) or GRE tunnels?  If not, some justification is needed since many multicast deployments use tunnels.

* Section 4 jumps right into the two ways of getting multicast data to the MAG (direct routing and the MTMA) without providing any guidance as to when each of the approaches is applicable or describing *how* the modes are selected.  Based on text elsewhere, I assume these modes are manually selected by the operator.  It would be good to provide some operational guidance.

* Section 4.1 references the "binding update list (BUL)" without any context.  It would be good to provide either a brief description of what it is or a reference to the document that defines it.

* Figure 3 does not show any MLD/IGMP traffic coming from the MTMA. Based on the description of the MTMA, I assume it must utilize multicast routing protocols and should be acting as an MLD Querier.  When the MAG provides its aggregated MLD Report, is that an unsolicited report or is it driven by the reception of an MLD Query?

* Section 4.2.2 references RFC 3810 when it is talking about MLD Proxy operation.  The reference should point to RFC 4605.

* In 4.2.2, I cannot parse the following : " ... an upstream interface of MLD Proxy instance is decided towards certain multicast router..."  I would be good to reword that sentence (and possibly break it into two sentences).

* Section 5.1.2, why does the option format only allow one Multicast Address Record?  MLD Report messages can carry multiple address records to minimize overhead, so why the limitation here?

* In general, there does not seem to be sufficient discussion of the versions of MLD (or IGMP) supported with this method.  Is it strictly limited to MLDv2 (hence the reference to RFC 3810) or can MAGs, MTMAs, and multicast routers utilize MLDv1?

* Does the MTMA need any special considerations for support SSM or is it truly a multicast router?  It is unclear as to what the differences would be between the MTMA and a multicast router, especially given the text in section 3.1 that says "The MTMA can be considered to be a form of upstream multicast router".  I think there needs to be a crisper description of the MTMA.

Regards,
Brian

(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?

Experimental
Yes
Yes
(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 abstract is OK

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?

No

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?

The document has no substantive issues.

Personnel

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


Document Shepherd is Behcet Sarikaya Responsible Area
  Director is Brian Haberman
 
(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 chairs have reviewed the document and it 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.

(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 on the document.

(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.



Each author confirmed individually the IPR discolosure that has already been filed and each author individually confirmed that they are not aware of any other disclosures.

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

There has been an IPR claim in full conformance with the provisions of BCP 78
and BCP 79 have already been filed. The chairs have informed the Working Group of this IPR claim during the Working Group adoption call and also during the Working Group Last Call. No WG discussion has happened.

There has been another IPR disclosure filed recently (ID # 2074, revised ID # 2077). Since this was a late disclosure, we have run a 2nd Working Group Last call on the draft clearly informing the WG of this late 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? 

There is a strong consensus behind this solution.

(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.)

Nobody has threatened to appeal and the document has the backing of the WG as a whole.

(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.

No ID nit errors/warnings are present on the document

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

The document meets the review criteria.

(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?

No.

(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).

The document defines a new mobility option, the IANA registry is in Mobile IPv6, Mobility Options.

(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.

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 formal language segments exist.