Subject: [Monami6] FW: I-D ACTION:draft-hong-multipleif-mn-pb-statement-00.txt

From: "Yong-Geun Hong" <[email-masked]>
Date: Mon, 24 Oct 2005 10:39:15 +0900

Folks..

We have submitted an internet drat on analysis of multiple interfaces in a
mobile node
to monami6 WG. You can find the draft in the following link.
http://www.ietf.org/internet-drafts/draft-hong-multipleif-mn-pb-statement-00
.txt

Abstract:

   This document is an analysis of multiple interfaces in a mobile node
   using Mobile IPv6 or a mobile router using NEMO Basic Support.  The
   current Mobile IPv6 and NEMO Basic Support are suitable for a single
   network interface.  When a mobile node or a mobile router has
   multiple interfaces, the current Mobile IPv6 and NEMO Basic Support
   cannot directly be used for them.  In this document, we describe some
   problems for a mobile node which has multiple network interfaces when
   the mobile node is using Mobile IPv6 as an aspect of a node.

We have researched the interworking between CDMA and WLAN and have
implemented
a mobile node using Mobile IPv6 and a mobile router using NEMO Basic Support
with one
CDMA network interface and one WLAN network interface. During this research
and 
implementation, we have met some problems and described them in that draft.

Welcome any question and any comments.

Thanks..

Yong-Geun..

-----Original Message-----
From: [email-masked] [mailto:[email-masked]]
On Behalf Of [email-masked]
Sent: Friday, October 21, 2005 11:50 PM
To: [email-masked]
Subject: I-D ACTION:draft-hong-multipleif-mn-pb-statement-00.txt 

A New Internet-Draft is available from the on-line Internet-Drafts
directories.

	Title		: Analysis of multiple interfaces in a Mobile Node
	Author(s)	: Y. Hong, et al.
	Filename	: draft-hong-multipleif-mn-pb-statement-00.txt
	Pages		: 10
	Date		: 2005-10-21
	
   This document is an analysis of multiple interfaces in a mobile node
   using Mobile IPv6 or a mobile router using NEMO Basic Support.  The
   current Mobile IPv6 and NEMO Basic Support are suitable for a single
   network interface.  When a mobile node or a mobile router has
   multiple interfaces, the current Mobile IPv6 and NEMO Basic Support
   cannot directly be used for them.  In this document, we describe some
   problems for a mobile node which has multiple network interfaces when
   the mobile node is using Mobile IPv6 as an aspect of a node.

A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-hong-multipleif-mn-pb-statement-00
.txt

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---

From: Romain KUNTZ <[email-masked]>
Date: Tue, 25 Oct 2005 15:01:19 +0900

Dear Yong-Geun Hong,

I have some technical comments about your drafts 
draft-hong-multipleif-mn-pb-statement-00 and 
draft-hong-virtualif-mn-mipv6-00.

About MIPL, the current code has some parts related to interface 
preference mechanisms. It does not work properly yet, but some patchs 
have been sent by users to the MIPL ML to solve the problems (though I 
cannot ensure it does not break anything). You can specify a preference 
for each interface and mip6d will listen to both interfaces 
simultaneously and take care of choosing the best available interface.

About Heterogeneous Environments, you speak about v4-only access on CDMA 
interface. I believe you never roam on the CDMA interface, so a 
tunneling system would fit to your problem (l2tp, or DTCP). If not you 
may take a look at draft-ietf-mip6-nemo-v4traversal-00.txt

Another comment: the problem statement sticks too much to implementation 
issues, not to generic issues related to multihoming. I mean "Problem 
statement" is maybe too strong for this document.

Regards,

-- 
Romain KUNTZ
[email-masked]

---

From: "Yong-Geun Hong" <[email-masked]>
Date: Wed, 26 Oct 2005 14:53:52 +0900

Dear Romain KUNTZ..

Thank you for your comments.

> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Romain KUNTZ
> Sent: Tuesday, October 25, 2005 3:01 PM
> To: Monami6 WG
> Subject: Re: [Monami6] FW:I-D 
> ACTION:draft-hong-multipleif-mn-pb-statement-00.txt
> 
> 
> Dear Yong-Geun Hong,
> 
> About MIPL, the current code has some parts related to 
> interface preference mechanisms. It does not work properly 
> yet, but some patchs have been sent by users to the MIPL ML 
> to solve the problems (though I cannot ensure it does not 
> break anything). You can specify a preference for each 
> interface and mip6d will listen to both interfaces 

Although we did not use the patch version until now, we also tried a similar
way. 
But, after considering many points, we have thought that the virtual
interface model can
solve problems without modifying Mobile IPv6 module. And it can be one
solution to solve 
the problems of multiple interface mobile node.

> 
> About Heterogeneous Environments, you speak about v4-only 
> access on CDMA interface. I believe you never roam on the 
> CDMA interface, so a tunneling system would fit to your 
> problem (l2tp, or DTCP). If not you may take a look at 
> draft-ietf-mip6-nemo-v4traversal-00.txt

Why do you believe we never roam on the IPv4 CDMA interface?
In our case, we use one WLAN interface and one CDMA interface.
As you know, the service area of WLAN is limited; only around of access
points.
If we want to use Mobile IPv6 or NEMO in non-WLAN server area, we must use
IPv4 CDMA interface currently (Before IPv6 is fully deployed in CDMA
network).

We also use dynamic tunneling to solve the problem.

> 
> Another comment: the problem statement sticks too much to 
> implementation issues, not to generic issues related to 
> multihoming. I mean "Problem statement" is maybe too strong 
> for this document.

In some points, you are right. Before implementing, we did not
consider some indicated issues. During implementing, we have met
these issues and we must solve them. These issues are real problem.
Some indicated issues are not generic issues related to multihoming but
generic issues related to multiple interface node. 

Thanks..

Yong-Geun..

---

From: Romain KUNTZ <[email-masked]>
Date: Wed, 26 Oct 2005 16:52:55 +0900

Hello,

> the problems of multiple interface mobile node.

The virtual interface model is a good idea when you plan to use several 
interfaces, but not at the same time. What if you want to use several 
interfaces at the same time? The model cannot apply, am I wrong?

> As you know, the service area of WLAN is limited; only around of access

I did not express my self correctly. I understand that you roam from 
WLAN to CDMA. What I mean is when you use the CDMA interface, you never 
handoff between access networks (your IPv4 address remains the same as 
long as you use the CDMA interface, even while moving). Thus in that 
case an usual tunneling mechanism can be used.

Regards,

-- 
Romain KUNTZ
[email-masked]

---

From: "Yong-Geun Hong" <[email-masked]>
Date: Thu, 27 Oct 2005 14:23:03 +0900

Hello..

Comments inline..

> Sent: Wednesday, October 26, 2005 4:53 PM
> To: Monami6
> Subject: Re: [Monami6]FW:I-D 
> > Although we did not use the patch version until now, we 
> also tried a 
> > similar way.
> > interface model can solve problems without modifying Mobile IPv6 
> > module. And it can be one solution to solve the problems of 
> multiple 
> > interface mobile node.
> 
> The virtual interface model is a good idea when you plan to 
> use several interfaces, but not at the same time. What if you 
> want to use several interfaces at the same time? The model 
> cannot apply, am I wrong?

 Thank you for your comments about the virtual interface model.
 We think that we can use multiple interfaces at the same time.
 There is no obstacle to use multiple interface simultaneously using 
the virtual interface model.
 I wonder why you think that.

> > As you know, the service area of WLAN is limited; only around of 
> > access points.
> 
> I did not express my self correctly. I understand that you 
> roam from WLAN to CDMA. What I mean is when you use the CDMA 
> interface, you never handoff between access networks (your 
> IPv4 address remains the same as long as you use the CDMA 
> interface, even while moving). Thus in that case an usual 
> tunneling mechanism can be used.

In our case, WLAN is connected to one access router and CDMA is connected
to another access router. So roam from WLAN to CDMA makes handoff between
access networks. (IP address is changed)

Thanks..

Yong-Geun..

---

From: Romain KUNTZ <[email-masked]>
Date: Thu, 27 Oct 2005 14:51:01 +0900

Hi,

>  I wonder why you think that.

To use multiple interfaces simultaneously, you have to register the CoA 
of each interface to the Home Agent(s) (ie send several BUs), handle 
policies for each interface etc. You may also have events on several 
interfaces at the same time. How can you handle this with the virtual 
interface model?

> access networks. (IP address is changed)

Yes, I understood that. I am not talking about vertical handoff. What I 
said was about the horizontal handoff with CDMA. But in the meantime 
John Loughney learned us that horizonthal handoff are also possible with 
CDMA, so my comment does not apply anymore.

Regards,

-- 
Romain KUNTZ
[email-masked]

---

From: "Joo-Chul Lee" <[email-masked]>
Date: Thu, 27 Oct 2005 20:18:47 +0900

Hi folks.

I have some question and comments. :-)
Read inline please.

> From: [email-masked] [mailto:monami6-
> [email-masked]] On Behalf Of Romain KUNTZ
> Sent: Thursday, October 27, 2005 2:51 PM
> To: Monami6 WG
> Subject: Re: [Monami6]FW:I-D ACTION:draft-hong-multipleif-mn-
> pb-statement-00.txt
> 
> 
> Hi,
> 
> Yong-Geun Hong wrote:
At this point, I wonder if "each interface" means an interface
that includes virtual-interface concept or just physical
interface? 
If what you mean is the latter case, IMHO, even if there are
several CoA(s) per physical interface that comprises the
virtual-interface the Interface-Switching-module can select
proper CoA(s) to register. 

> Yes, I understood that. I am not talking about vertical
handoff.
> What I

---

From: Romain KUNTZ <[email-masked]>
Date: Fri, 28 Oct 2005 16:16:34 +0900

Hi,

> proper CoA(s) to register. 

I was speaking about several "physical interface" that you want to use 
_simultaneously_, ie for example by registering the CoA of _each_ 
interface (as proposed in draft-wakikawa-mobileip-multiplecoa for 
example). I am not sure how you can deal with that with only one virtual 
interface.

Regards,

-- 
Romain KUNTZ
[email-masked]