Subject: RE: [mobile-ip] Multiple tunnels over unoptimized route packets f or Extended mode

From: "Hesham Soliman (ERA)" <[email-masked]>
Date: Thu, 29 Mar 2001 18:49:02 +0200

> >         - A handover works like this :
> >         The MR moves (uses FH or anything else), it advrtises
> >         a new MAP's address for the MNs behind it. The MNs
> >         then register the new address with the (fixed) MAP.
> 
> sure the moving MAP advertises its new LCoA...to the MN's that hang
> underneath it...we knew that
> 
	=> Then why do you assume that packets are sent to the MR's 
	Home address (below)? Are these packets addressed to
	the MN or the MR ?

> think what happens when a route unoptimized packet leaves the MN's HA..what
> happens... (one tunnel already)
> 
> it will have to arrive at the domain of the supporting MAP (but this is
> mobile). Since the packet is addressed to MR's home address , the MR's HA
> will HAVE to intercept it
> 
	=> As the draft says the packets are addressed to the MR's CoA.

>  and tunnel it to the RCoA it has for it MR (here
> the MR acts as a plain HMIPv6 node). We have two tunnels already..
> 
> Once the packet arrives at the RCoA of the MR it will have to be intercepted
> by its MAP (which must be working at Basic mode since it is not an MR)
> 
	=> From the draft:
	" 7. Extended mode: Supporting Mobile Nodes and Mobile Networks"
	   The Extended mode of operation can support both Mobile Nodes and
	   Mobile networks."

	I don't know why you assume the a MAP is only operating in 
	extended mode if it's MR. Did the draft give that impression ?
	If so please let us know where.

	Hesham

---

From: Theo Pagtzis <[email-masked]>
Date: Thu, 29 Mar 2001 11:59:35 -0800

Hesham,

   you either don't want to understand what I am saying or the email program
manages to shuffle my writing so that it arrives
to you in the way you want to interpret it... :)

The MN's HA has a binding. The first time that the MN moves under the MR/MAP it
will use as CoA the LCoA. But hey this is the home address of the MR. Needless to
say the protocol couldn't care less about that. It is just a LCoA of the MR/MAP
(So forget the term home address of the MR in this book..)

Packets from the MN's HA would arrive tunneled at that LCoA (route unoptimized)
(one tunnel)
In that time the vehicle that was carrying that MR/MAP  went away. That means to
me, that the MR acts as an HMIPv6 node and as a MR/MAP. So what does it do? It
gets itself a RCoA on a fixed MAP (Hello Basic Mode). That fixed MAP will tunnel
all packets sent to that RCoA.

NOW......the packet that was destined to the old LCoA of the MR/MAP (binding did
not get updated yet since the packet left after the vehicle went away, like an
aircraft would do). So what happens, the packet arrives at the domain of the
MR/MAP (since destined to its LCoA), the HA  of THAT MR/MAP will intercept it and
tunnel it blindly to the RCoA of its node (MR/MAP).

So the fixed MAP will receive it. As a nice HA instantiation it will see it was
destined for the RCoA get the binding entry and tunnel again the packet to the
LCoA of the MR/MAP. That is the binding of the node that registered THAT RCoA.

If you count the tunnelings are 3.

At some time point X the MN will send a BU to the HA that updates the binding, to
be the MAP/MR. However, in the mean time the MN's HA would have to send packets
to its old CoA (MR old LCoA).

I do not think I confuse anything. I simply describe how your protocol works in
that case.

Also you have not mentioned how is the distance metric evaluated in the selection
of the MAP in the extended mode. I can only assume shortest one is selected.

Theo

UCL/ Mobile Systems