Subject: [Fwd: [mobile-ip] AD review commments on draft-ietf-mobileip-ipv6-19.txt]

From: Brett Pentland <[email-masked]>
Date: Fri, 15 Nov 2002 10:23:51 +1100

Subject: Re: [mobile-ip] AD review commments on draft-ietf-mobileip-ipv6-19.txt
From: Brett Pentland <[email-masked]>
To: [email-masked]
Cc: Thomas Narten <[email-masked]>
Date: Wed, 13 Nov 2002 14:49:26 +1100

This suggestion to pull the performance optimisations out of the base
spec and put them into a separate document sounds like a sensible idea,
especially if they are going to be the really contentious items that
slow down the progress of the base document.

There have been a number of optimisations discussed on the list in
addition to those that are in the MIPv6 draft:

Optimistic DAD -
<http://www.ietf.org/internet-drafts/draft-moore-ipv6-optimistic-dad-00.txt>
Fast router advertisements - 
<http://www.ietf.org/internet-drafts/draft-mkhalil-ipv6-fastra-02.txt>
Fast router discovery with AP notification - 
<http://www.ietf.org/internet-drafts/draft-jinchoi-l2trigger-fastrd-01.txt>
Duplicate Address Detection Optimization using IPv6 Multicast Listener
Discovery - 
<http://www.ietf.org/internet-drafts/draft-daley-ipv6-mcast-dad-01.txt>

to name a few that leap to my mind (there are probably others)

This optimisation document sounds like a good place to consolidate these
techniques, explain their relationships and debate their relative
merits.

Any thoughts?
Brett.

Thomas Narten wrote:
> 
> The WG has requested that this document be advanced. I have reviewed
> the document and have a number of comments on it. Many are
> editorial/clarification type questions, which will be sent in a
> separate note. Here are some of the more general comments I have. My
> sense is that based on the number of comments and issues, this
> document is not ready for IETF LC yet. On the other hand, I don't see
> any real show stoppers, and I've been told that a revised version can
> be produce fairly quickly, once there is agreement on the needed
> edits.
> 
> I'm not comfortable with text in the document that are basically
> modifications to ND that are not critical to basic MIP. Some
> modifications are clearly critical (new message options, etc.) But
> there are also a number of changes to the ND spec that are of broader
> applicability than to just mobile nodes. In particular, there is text
> along the lines of
> 
>   - one MAY skip DAD, if one feels like it
>   - one can send messages more frequently than called for in the ND spec
>   - one need not delay as long as the ND spec calls for when waiting
>     to send RS
>   - run DAD in parallel with using the address (optimistic DAD)
>   - etc.
> 
> See Section 7, and 7.5-7.6 in particular. But the spec also includes
> language that says if DAD fails, one should generate a new IID and try
> again. (Section 7.7)
> 
> Most, if not all of these changes have not been reviewed by the IPv6
> WG, AFAIK. I see two ways of handling this:
> 
> a) point the IPv6 WG to the document and ask them to
>    comment/review. But I suspect that this will not be a short
>    discussion.
> 
> b) Pull much or all of this text out of the MIP spec, put it in a
>    separate ID, and then run it through the process separately (i.e,
>    don't hold up the MIP spec). I don't think these changes are
>    critical to MIP in a normative sense. They are optimizations that
>    will make MIP work better. I think we can target getting a
>    separate document in about 6 months.
> 
> After some preliminary discussion with the MIP and IPv6 chairs, the
> latter approach seems to be the preferred one.
> 
<snip>