Subject: RE: [Mip6] comments on draft-ietf-mip6-dsmip-problem-01.txt

From: "Soliman, Hesham" <[email-masked]>
Date: Fri, 4 Nov 2005 15:39:35 -0500

> I was asked to review this draft. I attach my comments.

Thanks Gabriel, 

A couple of discussion points below:

	In general, I found it refreshingly short and simple. It does focus on the tunnel
	set-up aspects of IP mobility. But there's movement detection, FA discovery or
	router discovery, prefix discovery, liveness detection, etc. Either these other
	areas should be taken into consideration or the problem statement should be
	modified to explicitly address only the tunnel set-up aspects of mobility.

=> Agreed. We will make it clear that the draft is specifically
addressing tunnel setup issues.

	>    IPsec security associations, keying material, and new authentication
	>    protocols for Mobile IPv6, in addition to the security credentials
	>    and associations required by Mobile IPv4. Such duplication is again
	>    significant with no gain to the operator or the mobile node.

	"no gain"? I think this is not correct. There is some gain, presumably.
	The argument I think is more along that it seems doable to obtain the same
	gain with much fewer resources.

=> The "no gain" part is referring to the duplication of security
credentials. What is the gain from doing that?

	>    layers. Given that Mobile IPv4 is currently deployed and Mobile IPv6
	>    is expected to be deployed, there is a need for gradual transition
	>    from IPv4 mobility management to IPv6. Running both protocols

	This presupposes only one of several possible deployment scenarios.
	Here, the assumption is that devices become mobile via MIP4 first, and
	then migrate to MIP6. 

=> I don't think it presupposes that. This is a fact today: Where MIP
is deployed (it is deployed widely in some commercial networks), It 
is only MIPv4. There is no commercial MIPv6 deployment today that
I'm aware of.

      But it may be that a significant population of
	devices will only know MIP6 mobility. They may use IPv4 (without mobility)
	to increase their chances of attaching to the net wherever they visit,
	but would only use IPv4 as an underlay for IPv6 (including mobility).
	So perhaps the MIP4->MIP6 upgrade scenario is not the only
	possibility (as implied here), and the draft should acknowledge that.

=> I completely agree that the above scenario is not the only possible
deployment scenario. We will clarify that in the next revision.

	>    Further work in this area, possibly independent of Mobile IP, may
	>    also be of interest to some parties in which case it should be dealt
	>    with separately from the incremental Mobile IP based changes.

	Not sure what this last paragraph adds. Perhaps delete it.

=> It was added because some people wanted to indicate that HIP
can be used instead of MIP. I agree it doesn't add value and have
no problems with removing it, unless people object.

Hesham

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From: gabriel montenegro <[email-masked]>
Date: Sat, 5 Nov 2005 00:36:30 -0800 (PST)

Hi Hesham

quick comment below

> credentials. What is the gain from doing that?

mipv6. what you seem to say is that to obtain that gain (mipv6) one does not
need additional security investment beyond that of mipv4 (but of course, instead
you'd need protocol investment, which is, after all, what your draft aims to
justify)