Subject: RE: [nemo] RFC 3963 on Network Mobility (NEMO) Basic Support Protocol- route optimization?

From: "Hsu, Julian P" <[email-masked]>
Date: Tue, 25 Jan 2005 11:49:21 -0800

Hi Alexandru,

Thanks for your reply!  I was especially heartened to find a NEMO
terminology internet draft on the site that you directed me to.  I am
interested in this topic because I am involved in system engineering for
a network architecture that has mobile networks with changing points of
connection to the infrastructure network.  Pretty much exactly what NEMO
seems to be addressing.

The restriction that LFNs go through the tunnel, though, can be
undesirable when the triangle routing from LFN to CN goes through say
more high latency, low bandwidth, etc. links than the optimized path..
Are there any developments or efforts towards solidifying alternatives
based on the MR trusting the LFN, or will running Mobile IPv6 within
those LFNs that would like to initiate their own RR tests be sufficient?

Thanks again,

Julian

-----Original Message-----
From: Alexandru Petrescu [mailto:[email-masked]] 
Sent: Tuesday, January 25, 2005 11:05 AM
To: Hsu, Julian P
Cc: [email-masked]
Subject: Re: [nemo] RFC 3963 on Network Mobility (NEMO) Basic Support
Protocol- route optimization?

Hsu, Julian P wrote:
> poster) question.  I notice that the RFC says that it does not 
> describe route optimization of traffic between nodes in the mobile 
> network and correspondent nodes, and later that it allows route 
> optimization for traffic originating from the Mobile Router.

Yes, exactly, MR can use RO just like any MH (Mobile Host, what people
call MN).  An application running on MR may easily enjoy the benefits of
RO as per RFC3775.

> Is there a discussion somewhere about the reasons for excluding mobile

> network nodes from the route optimization process?

RO discussion in the early archives in mobilenetworks.org/nemo/archives.

An application on LFN initiates communication to CN.  The MR is just in 
between and tunnels/detunnels.  The LFN does not implement RO because 
it's not Mobile IPv6 node.

How could MR send RR (Return Routability) tests to CN if that MR's Home 
Address is different than the LFN's address.  These two addresses are 
obviously different.  In order to make this "proxy" RR  (MR does RR "on 
behalf" of LFN) work there is need of some insurance at MR that it 
trusts the LFN and vice-versa.

> I couldn't tell from my readings of rfc 3775 on Mobility Support in 
> IPv6 and this RFC 3963 why it would not be straightforward to have the

> NEMO home agent allow route optimization to mobile network nodes known

> to be attached to a mobile router..

It's less a matter of HA, than a matter of MR and LFN.  LEss, but no 0.

I imagine HA uses its BC when participating in RR for rfc3775, and LFN 
does not have an entry in the BC (MR does).  The NEMO prefix may be in 
the BC, ok, but HA could not participate in RR tests for all Home 
Addresses of the NEMO prefix.

Why are you asking?

Alex

---

From: Alexandru Petrescu <[email-masked]>
Date: Tue, 25 Jan 2005 21:16:51 +0100

Hsu, Julian P wrote:
> more high latency, low bandwidth, etc.

Right, if with systems engineering one could find out how undesirable is 
that triangle routing then it's same engineering that may propose a 
valuable idea.

> those LFNs that would like to initiate their own RR tests be sufficient?

I don't know.  I think one does not exclude the other.

Then, for each of the questions.  MR trusting the LFN - no idea whether 
anything was propsed up to now (other than maybe SEND, but that won't 
cross subnets and the moving network may be subnetted with FRs Fixed 
Routers).  Running Mobile IPv6 between LFN and CN then demands 
enhancements to LFN ("LFN" basically says "no Mobile IPv6") and to MR 
and to HA and presumably don't touch a 3775 RR CN.  Somehow MR and HA 
must do RR for the address of LFN, and that's not specified anywhere.

Remark, "LFN no Mobile IPv6" does not mean to me that LFN is forbidden 
to become a "MH", i.e. have a Mobile IPv6 stack.  It could very well be 
a MH that is "at home" in the moving network, i.e. does not use the 
tunnel when in the moving network and its HA is _within_ the moving 
network, on the same link (this MH uses a tunnel to MR when it leaves 
the moving network, or when it goes down below some FR in the same 
moving network).  This onboard HA could actually be the MR itself.

And from this, just use your imagination; but within the limits of 
systems engineering :-)

Alex

---

From: Carlos Jesús Bernardos Cano <[email-masked]>
Date: Wed, 26 Jan 2005 08:49:45 +0100

Hi Julian,

> those LFNs that would like to initiate their own RR tests be sufficient?

	We are working (within EU FP6 DAIDALOS project) on a solution exactly
for that (sort-of "proxy MR"). Preliminar results are already published
in a paper (MIRON: MIPv6 Route Optimization for NEMO) that can be found
at http://www.it.uc3m.es/cjbc/papers/miron_aswn2004.pdf. Of course,
comments are welcome.

	Kind Regards,

	Carlos J.

-- 
Carlos Jesús Bernardos Cano - http://www.netcoms.net
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