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

From: "Yong-Geun Hong" <[email-masked]>
Date: Wed, 26 Oct 2005 15:23:17 +0900

Folks..

I was asked to send the review and difference between 
draft-montavont-mobileip-multihoming-pb-statement-04.txt and
my draft by Nicolas.

I think that the draft
draft-montavont-mobileip-multihoming-pb-statement-04.txt 
is a good draft which describes the requirements from the point of view of 
multihomed mobile nodes operating Mobile IPv6 and defines some issues.
We also learn many things in this draft.

But, when we were implementing a multiple interfaces mobile node(mobile
router),
we thought that the draft do not perfectly handle the problems of multiple
interfaces
of a mobile node. 

I summarize the parts related to the issues of multiple interfaces in a
mobile node
within the draft (draft-montavont-mobileip-multihoming-pb-statement-04.txt)

=============================================================

1. Section 3. Requirements 
    3th paragraph [page 8] : 

   Basically, Internet connectivity is guaranteed for a MN as long as at
   least one path is maintained between the MN and the fixed Internet.
   In some cases, it may be necessary to divert packets from a (perhaps
   failed) path to an alternative (perhaps newly established) path (e.g.
   for matters of fault recovery, preferences), or to split traffic
   between multiple paths (e.g. for load sharing, load balancing).  The
   use of an alternative path must be transparent at layers above layer
   3 if broken sessions and the establishment of new transport sessions
   has to be avoided.

2. Section 3. Requirements 
    Last paragraph [page 9] :

  One has to consider whether these goals can be achieved with
   transparency or without transparency.  Transparency is achieved when
   switching between interfaces does not cause the disruption of on-
   going sessions.  To be achieved with transparency, a necessary (may
   or may not be sufficient) condition is for the end-point addresses to
   remain unchanged.  This is in-view of the large amount of Internet
   traffic today are carried by TCP, which unlike SCTP, cannot handle
   multiple end-point address pairs.

3. Section 5.6 (n, 1, n) : n ifaces, 1, HoA, n CoAs

4. Section 6.1.3 Media Detection 

5. Section 7.3 Flow redirection

=============================================================

In my draft, I describe some practical problems.

1. Mobile IPv6-specific Issues
 : When a mobile node has multiple interfaces, it must have the ability to
look at
  all RA messages from multiple network interfaces to determine network
movement.

2. General network Issues
 : The mobile node also must update the relation between a destination
address and
  a network interface when it changes a network interface.

3. Considerations for Heterogeneous Environments
 : For the mobile node in IPv4 based network

Although the draft(draft-montavont-mobileip-multihoming-pb-statement-04.txt)
covers 
the multihoming issues including multiple interfaces node, my draft is more
focusing on
multiple interfaces node.

We think that it is better to make another document for considering multiple
interface node.
The problem of multiple interfaces is not only in network layer or Mobile
IPv6 (NEMO) but also
in below layer (layer 2). Like Link-layer Event Notification in DNA WG, it
is better to consider
link-layer to make perfect monami6 solutions.

Thanks..

Yong-Geun.

> -----Original Message-----
> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Yong-Geun Hong
> Sent: Monday, October 24, 2005 10:39 AM
> To: [email-masked]
> Subject: [Monami6] FW: 
> I-DACTION:draft-hong-multipleif-mn-pb-statement-00.txt 
> 
> 
>  
> 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-p
> b-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-p
> b-statement-00
> .txt
> 
> 
> 
> _______________________________________________
> Monami6 mailing list
> [email-masked]
> https://www1.ietf.org/mailman/listinfo/monami6

_______________________________________________
Monami6 mailing list
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https://www1.ietf.org/mailman/listinfo/monami6

---

From: Thierry Ernst <[email-masked]>
Date: Wed, 26 Oct 2005 18:50:56 +0900

Hi,

Comments inline, but first, I would like to point out that a new version
of draft-montavont-mobileip-multihoming-pb-statement (i.e. -05) has been
sent Monday, but not yet announced (we hope it to be renamed to
draft-montavont-monami6-multihoming-pb-statement)

Here is the link:
http://www.nautilus6.org/doc/drafts/draft-montavont-monami6-multihoming-pb-statement-05.txt
http://www.nautilus6.org/doc/drafts/draft-montavont-monami6-multihoming-pb-statement-05.html

On Wed, 26 Oct 2005 15:23:17 +0900
"Yong-Geun Hong" <[email-masked]> wrote:
> is a good draft which describes the requirements from the point of
> view of multihomed mobile nodes operating Mobile IPv6 and defines some
> issues. We also learn many things in this draft.

Thanks.

> But, when we were implementing a multiple interfaces mobile
> node(mobile router),
> we thought that the draft do not perfectly handle the problems of
> multiple interfaces
> of a mobile node. 

Well, I have to admit our draft is not perfect and that it will deserve
more work. Any specific suggestions on how to improve it will be
welcome. 

> I summarize the parts related to the issues of multiple interfaces in
> a mobile node
> within the draft
> (draft-montavont-mobileip-multihoming-pb-statement-04.txt)
> 
>    Basically, Internet connectivity is guaranteed for a MN as long as
>    at least one path is maintained between the MN and the fixed
>    Internet. In some cases, it may be necessary to divert packets from
>    a (perhaps failed) path to an alternative (perhaps newly
>    established) path (e.g. for matters of fault recovery,
>    preferences), or to split traffic between multiple paths (e.g. for
>    load sharing, load balancing).  The use of an alternative path must
>    be transparent at layers above layer 3 if broken sessions and the
>    establishment of new transport sessions has to be avoided.
> 
>    transparency or without transparency.  Transparency is achieved
>    when switching between interfaces does not cause the disruption of
>    on- going sessions.  To be achieved with transparency, a necessary
>    (may or may not be sufficient) condition is for the end-point
>    addresses to remain unchanged.  This is in-view of the large amount
>    of Internet traffic today are carried by TCP, which unlike SCTP,
>    cannot handle multiple end-point address pairs.
> 

The problem you describe in your draft is an implementation specific
issue, as pointed out by Romain Kuntz.

In draft-montavont, we have a section "considerations for MIP6
implementation". So, at best some text could be added there.

>   a network interface when it changes a network interface.

The problem yoiu describe in your draft is related,  when considering a
mobile node, to  the HoA address, and you ranged it into a "generic
issue" because it can apply to a fixed node with multiple interfaces,
right?  I think this is a problem in which SHIM6 is qualified (how
to change the locator, but not the identifier). 

I agree that our text in draft-montavont should be improved in a fashion
similar to draft-ietf-nemo-multihoming-issues where such issues are
well described. 

> Although the
> draft(draft-montavont-mobileip-multihoming-pb-statement-04.txt) covers
> the multihoming issues including multiple interfaces node, my draft is
> more focusing on

The concern described in your draft is valid and is addressed
in draft-ietf-mip6-nemo-v4traversal-00.txt. 

Note that I do not consider it has a multihoming issues at all: it is
right that nodes equipped with multiple interfaces may be more concerned
with this issue, but this could also happen for a node with a single
interface (for instance, a node with a WI-FI interface roaming between
an IPv6 wireless LAN and an IPv4 wireless LAN. We already came across
this problem.

> We think that it is better to make another document for considering
> multiple interface node.
> The problem of multiple interfaces is not only in network layer or
> Mobile IPv6 (NEMO) but also
> in below layer (layer 2). Like Link-layer Event Notification in DNA
> WG, it is better to consider

Actually, I kind of agree that more text could be useful in
draft-montavont., in the same fashion as in
draft-ietf-nemo-multihoming-issues under the issue "Media Detection".
However, I think we disagree on the classification as I wouldn't
consider it as a MIP6-specific issue.

Thierry.

> >    using Mobile IPv6 or a mobile router using NEMO Basic Support. 
> >    The current Mobile IPv6 and NEMO Basic Support are suitable 
> > for a single
> >    multiple interfaces, the current Mobile IPv6 and NEMO Basic
> >    Support cannot directly be used for them.  In this document, we 
> > describe some

---

From: "Taewan You" <[email-masked]>
Date: Thu, 27 Oct 2005 12:27:39 +0900

Dear Thierry & all,

For your comment of general network issues in this draft
(draft-hong-multipleif-mn-pb-statement-00.txt), I have a comment. Please
read inline.

Thanks,
Best Regards,
Taewan You.

> From: [email-masked] [mailto:[email-masked]] On Behalf
> Of Thierry Ernst
> Sent: Wednesday, October 26, 2005 6:51 PM
> To: Monami6 WG
> Cc: [email-masked]
> Subject: Re: FW: [Monami6] FW:I-DACTION:draft-hong-multipleif-mn-pb-
> statement-00.txt
> 
> 
> 
> Hi,
> 

Even though this problem that end node should update the relation between
destination address and specific network interface to prevent dissonance
between active network interface and changed IP address was happened in
fixed end node, I do not agree that the SHIM6 should qualify this problem.

AFAIK, SHIM6 is considering environment where an end node has multiple paths
(multiple IPv6 address prefix) by connecting to different ISP that means
site multihoming. So site multihomed an end node does not have necessarily
multiple interfaces and it only has to obtain multiple addresses from
different site exit routers. But the mobile node equipped multiple
interfaces are down for discussion in MONAMI6 WG clearly.

Therefore, if we have consensus, which this problem must be solved for using
multiple interfaces, I think that the MONAMI6 is more suitable place than
SHIM6.

---

From: Nicolas Montavont <[email-masked]>
Date: Fri, 28 Oct 2005 15:48:35 +0000

Hi,

Just few remarks inline.

[...]

>>http://www.nautilus6.org/doc/drafts/draft-montavont-monami6-multihoming-
I just get a response from the secretariat, and the new revision will be 
draft-montavont-mobileip-multihoming-pb-statement-05.txt, because we 
couldn't change the name. Sorry for that.

[...]

>>implementation". So, at best some text could be added there.
Using RA reception to determine a movement or even to determine the 
availibility/unavailibility of an interface is an information that we 
want to consider in general. Note that in our revision, we changed media 
detection to failure detection, in order to consider all failure that 
can occur on the entire path between the MN and its CN. It can be on the 
media (interface connected or not at L2, or no IPv6 prefix on the link), 
or a failure on the path between the MN and the HA, or between the HA 
and the CN.

So, for me, RA reception is part of failure detection. We may have to 
add text to explicitly mention that it is considered. Anyway, I think we 
have lot of work to clarify failure detection.

>multiple interfaces, I think that the MONAMI6 is more suitable place than
Can you clarify what you mean by "the MN also must update the relation 
between a destination address and a network interface when it changes a 
network interface?

A "destination address" is a CN address, or a CoA?

[...]

Regards,

Nicolas