Subject: [seamoby] comments on draft-ietf-seamoby-mm-problem-00.txt

From: Roberts Philip-qa3445 <[email-masked]>
Date: Wed, 21 Feb 2001 13:41:46 -0600

I don't have many comments on this.  Since the point of the document is to
make the case that micromobility should be part of seamoby going forward
would it be possible to have a short section up front entitled
recommendations for the seamoby charter with the rest of the draft as
explanation?

The first concrete recommendation I see is this:
Seamless handoffs, while maintaining the same routable IP address of
   a Mobile Node or Mobile Network should be a work item for the
   SEAMOBY Working Group.

While this seems to be a very concrete item for the working group it's
difficult to see the problem statement in the rest of the document for which
this work would apply.  It appears to be a solution without a problem.
Specifically one might want to state a problem and then why a combination of
mobile ip fast handovers and regional registrations wouldn't suffice to
solve it.

In the goals section there is mention of intertechnology handoff (while
still being intradomain is implied I believe).  Some of the discussion in
the fast handoff design teams has been around whether there is a situation
in which one could have intertechnology handoffs without easily accomodating
a make-before-break scheme.  I was wondering if there were examples of that?
Don't think this needs to be in the draft just trying to be thorough.  

On the list of 10 goals in the comparison with Mobile IP it seems that 1-3
are already covered by Mobile IP as mentioned.  Are you suggesting 4 and 5
(FA/GFA/HA Configurability and Reliability) ought to be covered by a working
group other than Mobile IP?  Mobile IP has 6 in its charter but we haven't
seen a lot of drafts yet attempting to tackle the issue.

There are a few other interesting items in the document.  I was intrigued by
the idea of discovery of new access link and new access router, and
characteristics of those.  Fast handover is a fairly large problem with lots
of aspects.  Mobile IP solves one part of it.  There are other pieces that
need to be solved on the router side of it in routed networks.

One last comment.  I was hoping to find a definition of micromobility in the
definitions section.  Is it possible to add that?

Phil (not that one, the other one)

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From: Pat Calhoun <[email-masked]>
Date: Wed, 21 Feb 2001 12:50:20 -0800 (PST)

First a disclaimer: I am not here to argue for the I-D, I will let the authors
handle that enjoyable task, but I do have a couple of comments on what I've
read so far on the list.

> Seamless handoffs, while maintaining the same routable IP address of   a
> Mobile Node or Mobile Network should be a work item for the   SEAMOBY
> Working Group.

I agree that it would have been nice to have charter recommendations, but it
wasn't explicitely requested from the design teams, perhaps by error, but I
agre that the problem statement should be clear enough that one can derive
what the charter items would be.

> mobile ip fast handovers and regional registrations wouldn't suffice to

As Luca stated, the design team was explicitely told to work on defining the
actual problem. What you are asking would have required the team to start
looking at options. Doing so would have detracted them from forming the
problem statement.

more below...

> need to be solved on the router side of it in routed networks.

So the ADs specifically requested that we inform them of any conflicts with
the SeaMoby work and the Mobile IP work. We know that there have been many
proposed Micro-Mobility protocols in the Mobile IP WG, and SeaMoby was formed,
in part, to handle these protocols. 

So here is a proposal: Now that we have a problem statement (which may require
additional work), in order to satisfy the IESG request to state how the work
does not conflict with MIP, we need to list how Mobile IP does, or does not,
match against the problem statement. This will require an evaluation of Mobile
IP work items, and the problem statement. 

Do people feel this is the right approach?? Any other suggestions?

> definitions section.  Is it possible to add that?

At a minimum, this would be required. However, I know that the use of the term
micromobility was frowned upon during the conference calls, in favor for other
terms, and that be the reason for its absence.

> Phil (not that one, the other one)

PatC (Yeah, that one)

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From: "Dana L. Blair" <[email-masked]>
Date: Tue, 27 Feb 2001 08:31:19 -0500

>what the charter items would be.

I didn't think we were changing the charter.  Later emails indicated we can't
add to the charter only delete items.  I thought our statement that Phil R.
has restated was pretty clear.  We think that applying the same internet principle
used for fixed devices should apply to mobile devices.

>Do people feel this is the right approach?? Any other suggestions?

When you say Mobile IP do you mean the working group or the protocol ?

If the basic assumption of Mobile IP (working group or protocol) is a Home Agent, then
I think it is flawed and we should not be comparing ourselves to Mobile IP.  Somehow
we need to proceed with the requirements process which makes no assumption about
intelligent functionality within the middle of the network like a Home Agent since this
violates a basic principle that has allowed the internet to scale in a way that no
other network has.

thanks,
Dana

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From: Pat Calhoun <[email-masked]>
Date: Tue, 27 Feb 2001 07:27:53 -0800 (PST)

> >what the charter items would be. > 
> has restated was pretty clear.  We think that applying the same internet
> principle used for fixed devices should apply to mobile devices.

Correct, the charter isn't flexible. I believe that what was being requested
is a set of milestones that one would expect. However, as I stated, this was
never requested, and I am not expecting it. If it was requested, then I would
expect it.

moving on....

> >So here is a proposal: Now that we have a problem statement (which may
> require >additional work), in order to satisfy the IESG request to state how
> the work >does not conflict with MIP, we need to list how Mobile IP does, or
> does not, >match against the problem statement. This will require an
> evaluation of Mobile >IP work items, and the problem statement. 
> >

The protocol, which is currently owned by the WG.

> 
> If the basic assumption of Mobile IP (working group or protocol) is a Home
> Agent, 

correct.

> then I think it is flawed and we should not be comparing ourselves to
> Mobile IP.

Then a justification for this needs to be clearly stated during the
requirements phase.

>  Somehow we need to proceed with the requirements process which
> makes no assumption about intelligent functionality within the middle of the
> network like a Home Agent since this violates a basic principle that has
> allowed the internet to scale in a way that no other network has.

ok, seems fair enough. However, as I state above, I would highly encourage the
requirements gathering team to NOT use requirements that sound like Mobile IP
is being explicitely ruled out for no apparent reasong (e.g. does not use Home
Agent). Instead, make the team needs to make their case very clear, and
justify such requirements. We will need to defend these requirements to the
IESG.

PatC

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From: "Dana L. Blair" <[email-masked]>
Date: Tue, 27 Feb 2001 11:10:25 -0500

>Then a justification for this needs to be clearly stated during the

That is valid expectation.

>justify such requirements. We will need to defend these requirements to the

Agreed.

Dana