Subject: RE: [Mip6] I-D ACTION:draft-ietf-mip6-nemo-v4traversal-00.txt

From: "Soliman, Hesham" <[email-masked]>
Date: Tue, 25 Oct 2005 17:16:57 -0400

> > => I'm afraid you didn't understand the draft. We are 
 > working under 
 > > the premise that MIP is used to manage mobility. Other 
 > techniques are
 > >  outside the scope of this draft and this mailing list.
 > > 
 > > Based on that, we state that if you have an IPv4 home 
 > address and you
 > >  appear in an IPv6-only network you won't be able to maintain 
 > > connections using MIPv4 only.
 > 
 > Absolutely.  Note though that the urgency of a solution for this
 > scenario is much lower than the urgency of a solution for a v6 MN
 > connecting to a v4-only network, simply because there are much more
 > v4-only wireless access networks (than v6), no?

=> That's a strange conclusion IMO. If you agree the vast majority
of the Internet is v4 and hopefully slowly migrating to v6. Why would
you want to allow a MN to obtain a v4 CoA, while communicating with
everyone in the IPv4 Internet using an IPv6 home address??
Makes no sense to me. Either you think most of the Internet is 
v4 or not. You can't use that argument for the CoA and not for 
the HoA. 

 > And the two scenarios lead to the immediate question: why not running
 > both MIP4 and MIP6 on the mobile, so that when it connects to the
 > v4-only access it uses MIP4 and when it connects to the 
 > v6-only access
 > it uses MIP6.  

=> We keep going back in circles. If you're questioning assumptions then
please address the problem statement. It contains answers to all 
this. If you don't agree with those answers then we can discuss them
in that context.

 > I hope the answer is not 'because it is a burden'.  Running both MIP4
 > and MIP6 on a same MN should break something, which we could identify
 > and try to solve.  Currently it doesn't break anything, no?

=> It does! breaks roaming between v4 and v6 networks...
It also practically breaks the mobility management for those 
relying on MIP for real local mobility. It's pointless to send 
to signals to the same local agent for v4 and v6. 

Hesham

 > Alex

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From: Alexandru Petrescu <[email-masked]>
Date: Tue, 25 Oct 2005 23:35:28 +0200

Soliman, Hesham wrote:

> => That's a strange conclusion IMO. If you agree the vast majority of
>  the Internet is v4 and hopefully slowly migrating to v6.

Hesham, right, let's synchronize.  I was not saying vast majority of
Internet is v4, I was saying vast majority of wireless access systems
are v4.  In this case, the second scenario you've described in the
Problem Statement draft (v6 MN, v6 app, v4-only access network) is the
most valid and urgent.  Would you agree?

> Why would you want to allow a MN to obtain a v4 CoA, while 
> communicating with everyone in the IPv4 Internet using an IPv6 home 
> address?? Makes no sense to me.

Makes no sense to me on paper either, but let's address that later in
3-4 years when v6-only wireless access networks are more prevalent, so
implementation feedback could help.   Would you agree?

> Either you think most of the Internet is v4 or not.

I can't even dare at guessing Internet being more v4 or more v6, but I
know most wireless access systems for end-user consumers are v4.

> You can't use that argument for the CoA and not for the HoA.

Oh, I see.  No I can't.  Fact is though that I can logically say that
a marketed wireless device has more chances to acquire an IPv4 CoA than
an IPv6 CoA.

I can't compare number of available CoAs to available HoAs v4 or v6 and
I don't think I need that comparison to motivate the problem of a v6-HoA
 MN, v6 app on a v4-exclusively access network.

>> And the two scenarios lead to the immediate question: why not 
>> running both MIP4 and MIP6 on the mobile, so that when it connects 
>> to the v4-only access it uses MIP4 and when it connects to the 
>> v6-only access it uses MIP6.
> 
> => We keep going back in circles. If you're questioning assumptions 
> then please address the problem statement. It contains answers to all

Hesham, I keep being forwarded to the DS Problem Statement draft.
Whether one believes it or not - I have read it.  I have even identified
a paragraph with respect to which you've enlightened me - thanks for that.

To stop turning in circles, and knowing it's not us deciding, let's
deal.  I already said I believe IPv6 MN connecting to v4-only network
and v6 app is a problem and needs a solution.  I do.  Would you agree
with anything I've asked about?  Most notably about using MIP4 for
managing an IPv4 Home Address?  Or about MIP4 doing v4 prefixes instead
of MIP6 doing v4 prefixes?

>> I hope the answer is not 'because it is a burden'.  Running both 
>> MIP4 and MIP6 on a same MN should break something, which we could 
>> identify and try to solve.  Currently it doesn't break anything, 
>> no?
> 

Ok, how about this: a v6 MN with MIPv6 using MIP4's UDP traversal and
running v6 app.  This would not break mobility between v4 and v6 access
networks for that v6 app.

> It also practically breaks the mobility management for those relying
> on MIP for real local mobility. It's pointless to send to signals to
> the same local agent for v4 and v6.

Is it more meaningful to send one single larger BU than two smaller BU
and RegReq?

Alex