Subject: [mobile-ip] Regional Registration Last Call Resolution Issue #1

From: Phil Roberts <[email-masked]>
Date: Thu, 9 May 2002 10:41:32 -0400

There were a few comments questioning whether or not this draft should be
published as a proposed standard at all, specifically whether it provides
useful functionality, or functionality that is not otherwise available, or
is described in a way that makes it clear to what extent it is optional to
implement.  A separate thread will address the issue of whether this draft
should be published because it raises issue with fundamental architectural
principles in the Internet.

The document clearly states what it is attempting to do - reduce
registration messaging traffic across the Internet, and reduce the handover
latency when Home Agents are far from the Mobile Nodes which they serve.
There has been expressed interest in the working group for pursuing this and
there continues to be interest in doing so.

There were suggestions that these requirements might better be served by the
low latency draft (draft-ietf-mobileip-lowlatency-handoffs-v4-03.txt).  The
techniques can be deployed in a 
complementary fashion.  Low latency discusses how the drafts can be used
together (see Appendix A). Given that the only plans for advancing
lowlatency now are in an experimental status, offering to replace this with
that doesn't necessarily advance the interests of the community.

Another issue was raised as to what extent it is optional to implement the
functionality described here.
Given that it can be made clear that this is optional to implement, there is
interest across the working group in doing so, and the proposed alternate is
only experimental, these objections are not sufficient to stop the advance
of this document to Proposed Standard.

Attached below is modified text for the abstract and the introduction,
Annika's words based on input
from Madhavi.

Phil

"Abstract

Using Mobile IP, a mobile node registers with its home agent each time it 
changes care-of address. If the distance between the visited network and 
the home network of the mobile node is large, the signaling delay for these 
registrations may be long. This document describes a new kind of "regional" 
registration, i.e., registration local to the visited domain. The regional 
signaling is performed via a new network entity called a Gateway Foreign 
Agent and introduces a layer of hierarchy in the foreign domain. Regional 
registrations reduce the number of signaling messages to the home network, 
and reduce the signaling delay when a mobile node moves from one foreign 
agent to another, within the same visited domain. This document is an 
optional extension to the Mobile IP protocol."

"Introduction

This document is an optional extension to the Mobile IP protocol, and 
proposes a means for mobile nodes to register locally within a visited 
domain. By registering locally, the number of signaling messages to the 
home network are keept to a minimum, and the signaling delay is reduced.

In Mobile IP, as specified in RFC 3220 [9], a mobile node registers with 
its home agent each time it changes care-of address. If the distance 
between the visited network and the home network of the mobile node is 
large, the signaling delay for these registrations may be long. We propose 
a solution for performing registrations locally in the visited domain: 
regional registrations. The regional registration design introduces new 
Mobile IP messages - Regional Registrations, new Mobile IP extensions to 
convey information between the mobile node, foreign agent, and home agent, 
and a new network entity - Gateway Foreign Agent (GFA). Regional 
registrations reduce the number of signaling messages to the home network, 
and reduce the signaling delay when a mobile node moves from one foreign 
agent to another, within the same visited domain. This will both decrease 
the load on the home network, and speed up the process of handover within 
the visited domain. The introduction of a GFA also makes it possible to 
have different addressing realms in the home and in the visited networks."

The last three paragraphs of the Introduction are unmodified.

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 09 May 2002 10:12:10 -0500

Hello Phil,
  Can I suggest adding

This document is an 
optional extension to the Mobile IP protocol.

to every paragraph?
...  just a joke.
More seriously, is Mobile IP required to be implemented by every single 
networked computer in the world? If yes (apart from where does it say 
so?) then which one, mipv4 or mipv6? If mipv4 then it should not be 
mipv6, or vice versa?
  If no, the obvious conclusion?

Regards,

-- 
Behcet

---

From: "James Kempf" <[email-masked]>
Date: Thu, 9 May 2002 09:56:25 -0700

DISAGREE

Speaking as a working group member, there is a working group draft on
requirements for localized mobility management
(draft-ietf-mobileip-lmm-requirements-01.txt) which was primarily
intended for MIPv6, but could as well apply to MIPv4. If the WG really
wants a standard for MIPv4 LMM, then I think these requirements should
be regressed against the proposed solutions, including the low-latency
solution and the new drafts by Alan O'Neill, and a standards-track
solution chosen that best meets the requirements.

That said, I recognize that the authors have put a lot of work into this
design, and so I would support publishing it as experimental even if the
requirements regression did not result it it being chosen.

Finally, speaking as an IAB member, I have some concern about publishing
a draft as an Internet standard when there are outstanding questions on
its effect on the Internet architecture. I realize that was listed as a
separate question, but I don't think it can be disentangled from how to
publish this draft.

            jak

---

From: "Madhavi W. Chandra" <[email-masked]>
Date: Thu, 9 May 2002 13:03:54 -0400

> Annika's words based on input

DISAGREE...as written below.

As per the feedback we provided, it should be clearly stated in the
Abstract and Introduction that this architecture is OPTIONAL and not
required in typical Mobile IP deployments. Also, reference to the new
Section that will describe scenarios that may benefit from this
architecture should be included in the Introduction. The agreement to
include the new Section is to alleviate the doubts for the necessity
of this architecture.  Hopefully, the new Section will highlight when
the architecture is useful, and not when it is NOT.

I have provided Annika with the suggested text.  Please incorporate
the above comments.

Thanks,
Madhavi

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 09 May 2002 14:41:25 -0500

Hi Jim,

>solution chosen that best meets the requirements.
1. We have not even seen Alan's drafts, how can we secondguess Alan?
2. Regarding LMM requirements draft, can you be specific on where it 
would contradict  MIPv4 regreg?

>requirements regression did not result it it being chosen.
This somehow contradicts your previous paragraph. I am against having 
standards just because the authors worked hard. The history of telecom 
standards tells us the contrary.

>separate question, but I don't think it can be disentangled from how to
Sorry I missed this, what are the outstanding questions on the Internet 
architecture that MIPv4 regreg affects?

--behcet

---

From: "James Kempf" <[email-masked]>
Date: Thu, 9 May 2002 13:16:52 -0700

> would contradict  MIPv4 regreg?

It is up to the WG and the chairs to decide whether we should do this or
not, and up to the chairs and AD to decide how it should be done, if we
do it.

> standards tells us the contrary.

An experimental designation is not a standard. It says that it is
experimental. It could also be done as informational.

> architecture that MIPv4 regreg affects?

When Phil posts this as a discussion item, I will respond.

            jak

---

From: "Emad Qaddoura" <[email-masked]>
Date: Thu, 9 May 2002 23:17:21 +0200

James, Phil,

	I agree with James about the requirements aspect. " against the
proposed solutions".

	I have asked the authors question(s) about the real-time impact
to the MIP protocol? What is it really?

	Working with MIP protocol and mobility derivatives for many
years, I get worried about the added options and messaging for the MIP
signaling which ultimately impacts the data path. Until such view is
fully clear, I CAN ONLY IMAGINE this draft being in the experimental
stage and not on a standard track.

	Is the added complexity to the overall MIP architecture worth
the few MS for a trip to the home network/the added signaling message to
the home? Would such a delay/signal be tolerable as long as there is a
mechanism that handles data forwarding to the new FA similar to the one
in the low latency draft.
	
	Also, looking at from a services point view and a direction of
how handheld devices with dual access (or more) would be used, I
strongly believe (may be only me) that the granularity of the location
to the home network/info-provider would of high importance for location
based services. I don't want to know that my subscriber is visiting the
North section of town, I need to have more information about the
location so I can "push/send" more personalized data to him, i.e. his
favorite pizza restaurant.

Thx.
Emad. 

> -----Original Message-----
> From: [email-masked] [mailto:owner-mobile-
> [email-masked]] On Behalf Of James Kempf
> Sent: Thursday, May 09, 2002 6:56 PM
> To: Phil Roberts; [email-masked]
> Subject: Re: [mobile-ip] Regional Registration Last Call Resolution
Issue
> #1
> > There were a few comments questioning whether or not this draft
should
> be
> > There were suggestions that these requirements might better be
served
> by the
> > low latency draft
(draft-ietf-mobileip-lowlatency-handoffs-v4-03.txt).
> The
> > lowlatency now are in an experimental status, offering to replace
this
> with
> > Another issue was raised as to what extent it is optional to
implement
> the
> > Using Mobile IP, a mobile node registers with its home agent each
time
> it
> > the home network of the mobile node is large, the signaling delay
for
> these
> > Mobile IP messages - Regional Registrations, new Mobile IP
extensions
> to

---

From: Behcet Sarikaya <[email-masked]>
Date: Thu, 09 May 2002 16:09:24 -0500

EQ,
  You claim to have worked many years on MIP but I am not sure if you 
understand the fact that MIP DOES not deal with geographic location 
changes such as being in the north section of town, etc. neither do we 
deal with personalized data. IETF has geopriv WG that works on 
geographic location issues and simple WG deals with instant messages.
  I believe your other concerns had been answered by Charlie who is in 
China this week (my guess).

Thx.

--behcet

---

From: "Emad Qaddoura" <[email-masked]>
Date: Fri, 10 May 2002 11:17:40 +0200

Behcet,

	Well, I don't want to go into un-healthy debates of how much
someone understands mobility and its impact on service delivery and
services in general. I would say I AM SURE you have no idea about the
ultimate benefit of MIP and its mobility information, and your
statements below are VERY PRE-MATURE. Location information that is
provided by MIP would be of great importance to any service delivery
such as location based service which can be of personalized context and
fully depend on the granularity of the location. How the
mapping/translation happens, is not within this WG as you may know.

	I had some personal emails with Charlie and, yes I was promised
with some info, but did not get it yet. However, SINCE YOU ARE SO
confident about what was provided, why don't you point me to it, and IS
IT good enough to understand the impact of regional tunneling on the MIP
architecture? 

Thx
Emad.

> From: Behcet Sarikaya [mailto:[email-masked]]
> Sent: Thursday, May 09, 2002 11:09 PM
> To: [email-masked]
> Cc: 'James Kempf'; 'Phil Roberts'; [email-masked]
Issue

---

From: Annika Jonsson <[email-masked]>
Date: Mon, 13 May 2002 18:16:05 +0200

Hi Madhavi,

see below...

At 01:03 PM 5/9/2002 -0400, Madhavi W. Chandra wrote:
>required in typical Mobile IP deployments.

In the proposed text, both the Abstract and the Introduction _does_ say 
that this is an optional extension to MIP, so what are you disagreeing with?

>Also, reference to the new

I think that the text in the Introduction gives sufficent information about 
what makes regional registrations useful and see no need for an extra section.

Regards,
Annika

---

From: "Madhavi W. Chandra" <[email-masked]>
Date: Mon, 13 May 2002 12:37:37 -0400

HI Annika,

> that this is an optional extension to MIP, so what are you disagreeing with?

As I stated in the email above and in my writeup, it should say
clearly in the Abstract and Introduction that the architecture is
OPTIONAL *and not required in typical Mobile IP deployments.*  Since
this is not what you wrote above, we are DISAGREEING.
 
> what makes regional registrations useful and see no need for an extra section.

This is not what Charlie and I agreed to.  We agreed to a new
Section that describes where this architecture would be
useful...perhaps you can provide network architectures that would
benefit from the regional tunneling.  As per the agreement, the new
section would go into Section 3...probably Section 3.1 as Charlie
mentioned.  Refer to the original email thread on this.  If we had
thought that the Introduction was sufficient, the original email
thread would not have occured.  Please do not go back to square one. 

Thanks,
Madhavi

---

From: Annika Jonsson <[email-masked]>
Date: Tue, 14 May 2002 10:40:45 +0200

Hi Madhavi,

>On Mon, May 13, 2002 at 06:16:05PM +0200, Annika Jonsson wrote:

...

>this is not what you wrote above, we are DISAGREEING.

To me, optional means just that, that it is not required, and that, I 
think, is clearly stated. I don't like the expression "in typical Mobile IP 
deployments". What is a "typical" Mobile IP deployment, and will it always 
be the same?

>thread would not have occured.  Please do not go back to square one.

Sorry, I missed that. I went back to see what you and Charlie had written. 
You offered to help with  text, could you please do that?  I'm not really 
sure what you want in this new section, that's why I'm asking. In the 
Introduction now it says:

" If the distance between the visited network and the home network of the 
mobile node is large, the signaling delay for these registrations may be 
long. We propose a solution for performing registrations locally in the 
visited domain: regional registrations."
<snip>
Regional registrations reduce the number of signaling messages to the home 
network, and reduce the signaling delay when a mobile node moves from one 
foreign agent to another, within the same visited domain. This will both 
decrease the load on the home network, and speed up the process of handover 
within the visited domain. "

What would you like to add to that?

Regards,
Annika

> time it
> extensions to

---

From: "Madhavi W. Chandra" <[email-masked]>
Date: Tue, 14 May 2002 09:43:28 -0400

Annika,

> deployments". What is a "typical" Mobile IP deployment, and will it always 

Well, you can choose another word besides 'typical' then.  I want to
convey that not only is Regional Registration OPTIONAL, but not
required in *typical* (or whatever word you like) networks.  
For example, Route Optimization is also optional, but more of a need 
to alleviate triangle routing.  Do you see my point now?  

> Introduction now it says:

Annika, how can I provide you text for something that I am asking?  These are
the concerns that I raised initially.  We came to a good understanding 
that the authors would describe where the regional registration architecture 
is useful in another Section...you could articulate the network scenarios 
that would benefit.  The purpose of the Section is to assuage doubts on 
its applicability.

I offered to provide text for the OPTIONAL statements, which I did.

Instead of continuing in circles, perhaps we should wait until Charlie 
returns.

Regards,
Madhavi

---

From: Annika Jonsson <[email-masked]>
Date: Wed, 15 May 2002 10:55:53 +0200

Hi Madhavi,

>to alleviate triangle routing.  Do you see my point now?

I understand what you mean, but I disagree. You are saying that even though 
both route opt. and regional reg. are optional, route opt. is more 
important, or is likely to be used more, or something like that. That may 
be, I don't feel that I can predict that. But I totally disagree that this 
should in any way be expressed in an RFC. Route opt. will be used to avoid 
triangular routing, regional reg. will be used to reduce the number of 
signaling messages to the home network, and reduce the signaling delay 
within the same visited domain. That's what you need to know about them. 
Then it's up to those building the networks to decide what functions they 
think are important enough to use.

>Instead of continuing in circles, perhaps we should wait until Charlie

I can't speek for Charlie, of course, but I think that he would more or 
less agree with me. He usually likes people to propose text because that's 
the best way to understand what they want. But, we have been considering 
adding an Applicability section to the draft. In view of these discussions 
I think we should, and that will hopefully address your concerns.

Regards,
Annika

> > > > > > the home network of the mobile node is large, the signaling 
> delay for
> > > > > these
> > > > > > In Mobile IP, as specified in RFC 3220 [9], a mobile node 
> registers
> > > with
> > > > > > convey information between the mobile node, foreign agent, and 
> home
> > > agent,

---

From: Charlie Perkins <[email-masked]>
Date: Wed, 15 May 2002 02:24:26 -0700

Hello folks,

The discussion revolves around when regional registration might
be useful, and how to indicate that within the draft.

I think it's best to be very exact.  Regional registration will be
useful when there's too much signaling traffic from registration
traffic across the Internet all emanating from the same visited
domain and all caused by movement between foreign agents
in that same domain.  This is intuitive.

"Too much" is clearly a matter for determination by individual
systems and access networks.  If an access network does not
have this problem, then it does not need regional registration.

Whether or not a "typical" visited domain or access network
will have this problem is hard to say.  I do know that we undertook
this work originally with a clear mandate to get something to work,
presumably because people saw the need, and because we saw
the need ourselves.  In fact, the implementations and simulations
do show the effect, and that bolsters the intuition.

I don't it is possible to prove to anyone that they "need"
regional registration.  Nor QoS, nor multicast, nor voice-quality
handovers, nor ...  But if we have a good tool for people to use,
then they can more easily solve problems that require that tool.
It doesn't mean that everyone has the same problems.

The text contribution that I would like to see from
Madhavi or anyone would be something that would shed
more light on problems where regional registration is
clearly needed, or clearly not needed, along with enough
discussion to make the point.  It seems like good material
for an appendix.

I hope this is at least helpful in some way, and that further
discussion doesn't have to wait until I return.

Regards,
Charlie P.

> think are important enough to use.

....................................

---

From: "James Kempf" <[email-masked]>
Date: Sun, 19 May 2002 17:39:11 -0700

Hi Charlie,

What do you mean by "too much"?

My impression is not that the GFA is needed for traffic shaping, but
rather that it is primarily for reducing the latency impact of MIP
handover on the MN.

            jak

----- Original Message -----
From: "Charlie Perkins" <[email-masked]>
To: "Annika Jonsson" <[email-masked]>; "Madhavi W. Chandra"
<[email-masked]>
Cc: "Phil Roberts" <[email-masked]>;
<[email-masked]>
Sent: Wednesday, May 15, 2002 2:24 AM
Subject: Re: [mobile-ip] Regional Registration Last Call ResolutionIssue
#1