Subject: [Mipshop] WG Last Call for draft-ietf-mobileip-lmm-requirements-04.txt

From: gabriel montenegro <[email-masked]>
Date: Thu, 16 Oct 2003 00:23:54 +0200

Folks,

This message starts a mobileip WG last call on:

Localized Mobility Management Requirements
http://www.ietf.org/internet-drafts/draft-ietf-mobileip-lmm-requirements-04.txt

This draft will be sent to the IESG for advancement as Informational RFC.

Please send your comments to the [email-masked] discussion list.

WG Last call issued on : Oct 16, 2003
Expires on : Oct 30, 2003

Note: We expect MIPSHOP to be approved as a WG soon. After this,
a future revision of this document may undergo a name change to reflect its
status as a MIPSHOP (no longer MOBILEIP) WG document.
 
-gabriel (on behalf of MOBILEIP chairs)

_______________________________________________
Mipshop mailing list
[email-masked]
https://www1.ietf.org/mailman/listinfo/mipshop

---

From: Pekka Nikander <[email-masked]>
Date: Thu, 23 Oct 2003 17:37:57 +0300

> http://www.ietf.org/internet-drafts/draft-ietf-mobileip-lmm-requirements-04.txt 
...
> status as a MIPSHOP (no longer MOBILEIP) WG document.

The draft is now draft-ietf-mipshop-lmm-requirements-00.txt;
here are some comments that occured to me while reading the draft.

1. Title, content, and Mobile IP specifity

    The current title of the documents is "Localized Mobility
    Management Requirements".  However, already the abstract
    makes clear that the documetn only handles local mobility
    based on Mobile IP and Mobile IPv6 protocols.  I hate to be
    a pain, but I want to point out, once again, that there are
    also other ways of implementing mobility at the IP layer.

    A second point is that a number of working groups have recently
    had bad experiences with requirements documents.  It looks like
    a good way of avoiding some of these dangers to speak about
    goals, not requirements.  There has also been bad experience in
    using normative language (MUST, MUST NOT, etc)

    I would suggest that the document title is changed to reflect
    its content.  If the content is held as it is now, my suggestion
    for the new title would be the following:

      Goals for Mobile IP based Localized Mobility Management

    As an alternative, I would suggest that the document is reworked
    so that it would not be so Mobile IP focused.  However, I well
    know that such a modification is unlikely to happen.  On the other
    hand, some of the proposed LMM solutions would be also quite useful
    for the other IP mobility management schemes but Mobile IP.

    If the working group would be accepting, I would be willing to
    produce a version of the draft that would be neutral with respect
    to the baseline IP mobility solution.  The changes do not seem to
    be that large.

2. Formatting

    The draft does not come even close to ID nits in its formatting.
    I presume that the authors are well aware of this.

3. Goals

    I would suggest adding one more goal to Section 1.0:

      - introduce no new security vulnerabilities

4. Editorial

    Section 3.0 vs 3.1.   Section 3.0 states that the section applies
    both to IPv4 and IPv6.  Section 3.1 explicitly mentions "core
    Mobile IPv6".

    Section 3.4.2.  I don't understand what the following sentence
    is trying to say:  "This would involve MIP-specific routing
    state as binding caches in addition to standard routing table
    host routes."  I would suggest removing it.

    Section 3.4.4.  If you take the requirement literally, it would
    also mean that LMM MUST NOT make the performance any better :-)
    I would suggest rewording...

    Section 3.4.6.  Again, if the requirement is taken literally,
    it is indeed quite restrictive, ruling out all hierarchical
    schemes, for example.

5. I quite strongly disagree with the current security considerations
    section.  The document does have security requirements, and any
    LMM scheme will create new security issues that must be solved.

--Pekka Nikander

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From: gabriel montenegro <[email-masked]>
Date: Sat, 25 Oct 2003 03:17:55 +0200

Thanks Pekka,

> The draft is now draft-ietf-mipshop-lmm-requirements-00.txt;

Yes, thanks for pointing that out. Content is the same, that
was only a name change.

>    also other ways of implementing mobility at the IP layer.

It does look like you have a point here. All documents in
any of the mip4, mip6, mipshop and mobileip explicitly say
Mobile IP or IP Mobility. I presume you'd have some objection
to the latter, but certainly there's plenty of examples of
titles with the former as well. Perhaps a good new title
would be:

   Localized IP Mobility Management Requirements

or

   Requirements for Mobile IP Localized Mobility Management

This seems consistent with all other document titles.

>    using normative language (MUST, MUST NOT, etc)

Not sure what the issue is. If I search for "requirements" in the
titles of RFC's I get many hits, so unless something has recently
been uncovered as completely broken in thinking about similar
documents as requirements documents, I'd think there's no point
in making this change.

The main point, though, is that mipshop's charter does not make it
mandatory for its experimental protocols to comply completely with
this document. The charter says so explicitly, and this was added
precisely so people would not prevent publication of the protocol
spec because some detail was not compliant with the requirements
document.

>      Goals for Mobile IP based Localized Mobility Management

I'd suggest the titles above instead, but don't feel very
strongly either way. I'd like to hear what the WG and the
AD's think.

>    for the other IP mobility management schemes but Mobile IP.

This will not happen in this WG, it's outside our charter.

>    to the baseline IP mobility solution.  The changes do not seem to

This might be an interesting exercise, but it won't be an official
item unless we recharter.

I'd recommend you pursue it as an individual draft, or perhaps
pursue it in another group that does deal with mobility based
on schemes other than Mobile IP (HIP?).

>    I presume that the authors are well aware of this.

Carl is well aware as I've told him, yes. I hope it's clear
to the WG and authors that if ID nits are not completely
solved the document will not advance to the IESG (well,
the current chair won't do so).

>      - introduce no new security vulnerabilities

perhaps say what the baseline is, something along the
lines of: "...with respect to Mobile IP..."

I'll leave Editorial comments to Carl.

>    LMM scheme will create new security issues that must be solved.

Very good point! This section needs some work.

-gabriel

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From: Pekka Nikander <[email-masked]>
Date: Sat, 25 Oct 2003 10:56:47 +0300

Hi Gab,

gabriel montenegro wrote:
> ... Perhaps a good new title would be:

I would not be very happy with the one above, but I could live.  :-)

>   Requirements for Mobile IP Localized Mobility Management

 From my point of view, that would be a very good title
for the document.

>>    had bad experiences with requirements documents.  ...
> 

Ok.  I just wanted to make the comment.  multi6 has been the
worst example -- there the work stalled for over a year while
people took the word "requirement" too literally.

> this document....

Excellent -- I missed this.  Thanks for pointing this out.

>>    so that it would not be so Mobile IP focused. ...
> 

Well, it may not necessarily be so.  IMHO, there would be space
for a document that takes a fairly neutral starting point, but
still discusses Mobile IP, too.

Let me take one excerpt from the draft:

3.3.1 Any Localized Mobility Management protocol MUST NOT inject
       any additional functionality over base  Mobility [2, 3] at the
       Home Agent or any of its peer CNs.  Thus, the LMM framework
       MUST NOT add any modifications or extensions to the Correspondent
       Node(s) and Home Agent.

If I understand this correctly, this basically says that the
LMM protocol does not necessarily have anything to do with Mobile IP.
In particular, it says that it MUST NOT change the Mobile IP (or other)
protocol between the Mobile Node and Home Agent or the Mobile Node
and the Correspondent Node.

While it is certainly possible to fulfil this requirement in
a way that is very Mobile IP dependent, it is also certainly
possible to fulfil this requirement with a protocol that does not
depend on Mobile IP at all.

There are also other requirements in 3.3 which are very similar
in nature.

In my way of reading the document (which may be the devil's advocate's
way :-), the only requirements that really need even to mention
Mobile IP are 3.3, 3.5.1 and 3.9.  3.3 I discussed above.  3.5.1 is
about performance, and it could be easily expanded to cover also
other IP mobility solutions but Mobile IP.  I would be very happy
to keep 3.9 in the document; I think it an important requirement,
and basically (together with 3.3) states that the solution must
be compatible with Mobile IP.  From my point of view, that is a
very reasonable requirement.

> item unless we recharter.

See above; the case may not be that black and white.

> I'd recommend you pursue it as an individual draft...

Maybe I will do that.  However, it is not on the top of my
priority list right now.

Would the chairs be willing to give a few minutes on the
agenda if I put up such a draft, available at a web site,
before Minneapolis?  My purpose would not be to advocate
other solutions, but trying to make (once more) the point that
macro mobility and localized mobility do not architecturally
need to depend on each other.

> lines of: "...with respect to Mobile IP..."

Agreed.  That would be even better.

> Very good point! This section needs some work.

Excellent that we agree here!

--Pekka Nikander

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From: "James Kempf" <[email-masked]>
Date: Sat, 25 Oct 2003 02:31:03 -0700

Gab,

> spec because some detail was not compliant with the requirements

So what is the point of the requirements document then? 

            jak