Simple Virtual Aggregation (S-VA)
draft-ietf-grow-simple-va-12

[Ballot discuss]
I've been hesitating between a COMMENT and DISCUSS for some time on this one.

Since Jakob started to improve the draft (thanks for that), I thought about reading the new temporary version, as opposed to the official document on the IESG telechat: draft-ietf-grow-simple-va-09

Then, reading through this new draft, I see the following two comments:
- "Robert, I do not understand the following paragraph:"
- "Robert, I don't understand the lines prefixed with *. "
    Note: I counted 31 lines

So that gets me thinking: being a non native English speaker, I recognize the difficulty to write an IETF text, and, if it was only about improving the English, this would be a COMMENT.
However, I see an issue if one of the experts (i.e. an author) mentions that he doesn't understand what's in the draft!

So this DISCUSS is a placeholder while waiting for the next version (which was btw strongly suggesting by some IESG members in their COMMENTS). I will carefully review the next version.

[Ballot comment]
**word smith alert**

1) abstract: Isn't this about the router running out of memory for the FIB?

OLD:

must upgrade router hardware simply because the FIB has run out of space,

NEW:

upgrade router hardware simply because the server has run out of memory to store the FIB,

2) s1, 1st para: same issue as #1

3) s1: what's a partial default?  It's the default some of the time?

[Ballot comment]
These are non-blocking, but please consider them seriously, and feel free to chat with me about them:

This comment is on the edge of being a DISCUSS, but I think I'll try it this way: The document is generally OK, and I have great respect for the work of the non-native-English editors.  But there are some significant bits that are in sufficiently fractured English as to be hard to read and possibly confusing.  I've noted the worst of them below, but I'd like to see one of the native-English-speaking co-editors go over the document and make sure the articles, tenses, plurals, and commas are right.

Also, the document cites RFC 2119 and contains 2119 boilerplate, but I can only find one instance of a "MUST".  My sense is that this Informational document doesn't need 2119 at all, and that it should be removed.

The third paragraph of the Abstract doesn't seem to need to be in the Abstract, and I suggest removing it.  It's the sort of thing that will do fine in the Introduction only.

-- Introduction --

   Finally, provider defaults prevents the ISP from being able to detect
   martian packets.  As a result, the ISP transmits packets that could
   otherwise have been dropped over its expensive provider links.

Is "martian packets" a term of art, a bit of humour, or a typo?  If the first, is it sufficiently well known that it doesn't need explanation?  I don't understand it, but, then, I'm not steeped in this topic.  From the context, I can tell that it refers to packets that can safely be dropped.  [UPDATE... Lookie here!: Thanks to Robert for referring me to RFC 1208.  Who knew?  Shows you how much I don't know about things routing (or Martian).  Never mind this bit, then.  :-) ]

The second sentence, though, reads funny: it seems like you're talking about dropping packets over expensive links (rather than transmitting packets over them).  I think this is clearer:

NEW
As a result, the ISP transmits packets that could have been dropped, and sometimes does so over expensive provider links.

   Edge routers may install a default route to core routers, to ABRs
   which are installed on the Point of Presence (POP) to core boundary
   or to the ASBR routers.

With all the "to"s, and too few commas, I find it impossible to parse this sentence.  Please re-phrase and/or re-punctuate it so it's clearer.

   In configurations where BGP routes are used to resolve other routes
   or where BGP routes are redistributed to other protocols which both
   happen via RIB simple-va can rather then suppressing routes before
   they are installed in global RIB flag them as "suppress eligible".

Another incomprehensible sentence.  Please re-phrase and punctuate it.

-- Security Considerations --
   The authors are not aware of any new security considerations due to
   S-VA.

I believe that, but where *do* the security considerations come from?  From full VA?  If so, then it's probably a good idea to refer the reader to that document for security considerations.

[Ballot comment]

- This is not an easy read, but it ought be. For example,
section 2 says: "In both cases simple VA operates in an
identical way however when default route is found and is
eligible to become a less specific prefix by router's
configuration the S-VA may use it. " I'd encourage the
authors to try get some additional editorial review aiming at
significantly increased clarity. (This was also almost a
DISCUSS, but isn't since this algorithm doesn't seem
to affect security or interop, and if it did, deployments
would turn it off quickly.)

- Various terms (e.g., ABR, ABSR, SPF, Adj-RIBs-In, Loc-RIB,
NLRI, ...) could be expanded.  The terminology section even
seems to use undefined terms.

[Ballot comment]
These are non-blocking, but please consider them seriously, and feel free to chat with me about them:

This comment is on the edge of being a DISCUSS, but I think I'll try it this way: The document is generally OK, and I have great respect for the work of the non-native-English editors.  But there are some significant bits that are in sufficiently fractured English as to be hard to read and possibly confusing.  I've noted the worst of them below, but I'd like to see one of the native-English-speaking co-editors go over the document and make sure the articles, tenses, plurals, and commas are right.

Also, the document cites RFC 2119 and contains 2119 boilerplate, but I can only find one instance of a "MUST".  My sense is that this Informational document doesn't need 2119 at all, and that it should be removed.

The third paragraph of the Abstract doesn't seem to need to be in the Abstract, and I suggest removing it.  It's the sort of thing that will do fine in the Introduction only.

-- Introduction --

   Finally, provider defaults prevents the ISP from being able to detect
   martian packets.  As a result, the ISP transmits packets that could
   otherwise have been dropped over its expensive provider links.

Is "martian packets" a term of art, a bit of humour, or a typo?  If the first, is it sufficiently well known that it doesn't need explanation?  I don't understand it, but, then, I'm not steeped in this topic.  From the context, I can tell that it refers to packets that can safely be dropped.

The second sentence, though, reads funny: it seems like you're talking about dropping packets over expensive links (rather than transmitting packets over them).  I think this is clearer:

NEW
As a result, the ISP transmits packets that could have been dropped, and sometimes does so over expensive provider links.

   Edge routers may install a default route to core routers, to ABRs
   which are installed on the Point of Presence (POP) to core boundary
   or to the ASBR routers.

With all the "to"s, and too few commas, I find it impossible to parse this sentence.  Please re-phrase and/or re-punctuate it so it's clearer.

   In configurations where BGP routes are used to resolve other routes
   or where BGP routes are redistributed to other protocols which both
   happen via RIB simple-va can rather then suppressing routes before
   they are installed in global RIB flag them as "suppress eligible".

Another incomprehensible sentence.  Please re-phrase and punctuate it.

-- Security Considerations --
   The authors are not aware of any new security considerations due to
   S-VA.

I believe that, but where *do* the security considerations come from?  From full VA?  If so, then it's probably a good idea to refer the reader to that document for security considerations.

IANA has reviewed draft-ietf-grow-simple-va, which is currently in Last Call, and has the following comments:

IANA understands that, upon approval of this document, there are no IANA Actions that need completion.

The following Last Call announcement was sent out:

From: The IESG
To: IETF-Announce
CC:
Reply-To: ietf@ietf.org
Subject: Last Call:  (Simple Virtual Aggregation (S-VA)) to Informational RFC


The IESG has received a request from the Global Routing Operations WG
(grow) to consider the following document:
- 'Simple Virtual Aggregation (S-VA)'
  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 2012-06-12. 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


  The continued growth in the Default Free Routing Table (DFRT)
  stresses the global routing system in a number of ways.  One of the
  most costly stresses is FIB size: ISPs often must upgrade router
  hardware simply because the FIB has run out of space, and router
  vendors must design routers that have adequate FIB.

  FIB suppression is an approach to relieving stress on the FIB by NOT
  loading selected RIB entries into the FIB.  Simple Virtual
  Aggregation (S-VA) is a simple form of Virtual Aggregation (VA) that
  allows any and all edge routers to shrink their RIB and FIB
  requirements substantially and therefore increase their useful
  lifetime.

  S-VA does not increase FIB requirements for core routers.  S-VA is
  extremely easy to configure considerably more so than the various
  tricks done today to extend the life of edge routers.  S-VA can be
  deployed autonomously by an ISP (cooperation between ISPs is not
  required), and can co-exist with legacy routers in the ISP.




The file can be obtained via
http://datatracker.ietf.org/doc/draft-ietf-grow-simple-va/

IESG discussion can be tracked via
http://datatracker.ietf.org/doc/draft-ietf-grow-simple-va/ballot/


No IPR declarations have been submitted directly on this I-D.

Document Writeup

Write up for draft-ietf-grow-simple-va-04

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.

(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?

The recommended type of RFC is Information.  This is clearly stated
in the title page header.  Information is the recommended type because
the document is not on standards track, and there is an expectation
that the specified technology can be deployed.


(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

  Simple Virtual Aggregation (S-VA) is a simple form of Virtual
  Aggregation (VA) that allows any and all edge routers to shrink
  their RIB and FIB requirements substantially and therefore increase
  their useful lifetime.

  S-VA does not increase FIB requirements for core routers.  S-VA is
  extremely easy to configure considerably more so than the various
  tricks done today to extend the life of edge routers.  S-VA can be
  deployed autonomously by an ISP (cooperation between ISPs is not
  required), and can co-exist with legacy routers in the ISP.

Working Group Summary

  The document has has significant participation in the workgroup for
  sometime.  It is a group of three documents submitted to grow.  The
  other 2 are draft-ietf-grow-va-06, and draft-ietf-grow-va-auto-05,
  which extend this initial document.  This draft is an extension of
  the draft-ietf-grow-va-06.  At the final time of last call there
  were no objections.

Document Quality

  The document has been authored by both research members, and at least
  one vendor.  During last call specific people were requested to review
  the document including active ietf members with service provider
  expertise.

Personnel

  Peter Schoenmaker  is the document shepherd.
  Ron Bonica  is the AD

(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 document shepherd has reviewed the document, along with consulting
  with members of the community to ensure it has been properly reviewed,
  and is ready for publication.

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

  There are no concerns with the depth or breadth of the reviews
  performed.  Approaching last call there was waning comments and
  participation.  The shepherd ensured that a sufficient review
  was performed.
 
(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.

  The working group in which the document has been adopted in is composed
  of a wide number of active participants from the different areas.  It
  it believed that no further review is required.

(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.

    There is a concern that over time the level of interest in the
    document has fallen to a limited scope of people.

(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.

    There are no IPR issues tied directly to 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.

    N/A

(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?

    Last call was quiet.  Final review had to be personally sought.

(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 issue has been brought up.

(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.

  There are 3 warnings in the document.  These seems minor the the
  content of the document.  The shephard believes that a new
  revision will be required as part of the IESG review process
  at which time the authors will clean up the nits.

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

  The document does not require any of the formal 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 does not need any IANA considerations.

(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.

  See #17

(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.

  The document does not use any formal language