Subject: RE: GSE IDs [Re: IETF multihoming powder: just add IPv6 and stir]

From: "Christian Huitema" <[email-masked]>
Date: Tue, 13 May 2003 08:26:55 -0700

> >> But I think we should revisit this when there is an actual proposal
> >> that adds extra headers to packets because only then we'll be able
to
> >> see how this helps us and how it hurts us.
> 
> > Well, using MIPv6 could be one of such proposals (there are some
issues
> > to solve) but still can be useful to quantify the amount of overhead
> > involved.
> 
> Mobile IP in IPv6 uses a 24 byte header to carry the original source
> address, right?

It does, but it only needs to do so when negotiating a binding update.
The trick is to design a usage model of MIPv6 in which binding updates
are used to redirect a TCP connection (or a UDP flow) to a new address.

-- Christian Huitema

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From: marcelo bagnulo <[email-masked]>
Date: 14 May 2003 13:04:09 +0200

Hi Christian,

> are used to redirect a TCP connection (or a UDP flow) to a new address.

IMHO, it would be interesting to use the MIPv6 protocol in such a way
that changes are imposed to the CNs are as few as possible (Changing
Mobile Nodes behaviour, assuming that this role will be assumed by hosts
within the multi-homed site is acceptable).
So considering that MIPv6 already provides connection survivability
throughout network access point changes, it is would be interesting to
evaluate if it can be adapted to support multi-homing.
So, i would say that a MIPv6 based solution for multi-homing can be
evaluated considering the changes it imposes to CN.

However, from your comments above, i would say that you are considering
more substantial changes in the CN behaviour, perhaps you could expand
on this?

Thanks, marcelo

-- 
marcelo bagnulo <[email-masked]>
uc3m

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Wed, 14 May 2003 23:41:56 +0200

On dinsdag, mei 13, 2003, at 17:26 Europe/Amsterdam, Christian Huitema 

> are used to redirect a TCP connection (or a UDP flow) to a new address.

Christian, why did you have to do this???

All this time I managed to avoid reading the MIPv6 draft (no RFC 
yet...) but now I had to in order to be able to disagree with you.

On page 78 it says that there must be state in the binding cache AND 
the correspondent has to use a routing header. So there's something to 
hate there for everyone.

(I know I was talking about the source and not the dest address but 
that one is significantly more convoluted in the spec. Looks like the 
same thing applies, though.)

Unfortunately it isn't entirely trivial to remove the routing header 
and have the identifier^H^H^H^H^Hhome address be implied as this 
requires a mechanism to detect whether something is directed at the 
home address or the care-of address, which we need to know to do the 
checksums. Who's bright idea was it to include the addresses in the 
transport checksums anyway???