Subject: RE: (ngtrans) RE:

From: "Hesham Soliman (EPA)" <[email-masked]>
Date: Fri, 15 Sep 2000 03:13:58 +1100

Hi George,

>
> => they are routed according to IPv4 routing to the TEP, then
> they are IPv6 routed to the MN through the HA (if not optimized) or
> directly with a source-route (if optimized, I don't see a good
> reason to be and stay not optimized). If the TEP and the HA
> are colocated then you have twice the code on the box but the
> IPv6 routing is garanteed to be optimized (in fact as good as it can be).
>
        Francis covered the case in which the Home Network also runs DSTM.
In this case the MN will get an IPv4 address back and then it will have to
use IPv4 over IPv6(tep) over MIPv6 in order to send the packet to the Home
Agent or IPv4 over IPv6(tep) if the home TEP is directly reachable.

        The other case is when the Home Network DOES NOT run DSTM but it
does run DHCPv4. Is that what you are thinking? In this case the MN needs to
send a DHCPv4 packet over a MIPv6 reverse tunnel and get an IPv4 address.
This addressed will need to be relayed to the MN by the HA, which will also
now have to run proxy ARP for the IPv4 address of the MN in order to capture
incoming IPv4 packets. I think that one might be able to implement something
like a Home Agent that supports Mobile IPv4 and Mobile IPv6 but tunnels
everything over MIPv6 in order to accommodate the above case but I tried to
avoid this case in the draft since I was aiming for something simple.

=> Yes that is one of the cases I had in mind but not all.
Unfortunately, I think we might need some complexity here ;)
That's why I was wondering about the HA, because I understood
that you didn't want to run MIPv4 at all. Doing a proxy ARP
needs to be triggered by something. In MIPv4 that is a home
registration of course. That's what I'm missing.

This scenario made me think more about how TEP in general
maps IPv4 and IPv6 addresses.

Even in the other case where there is DSTM at home, If the
IPv6 node is in the foreign domain, does it not still need
to reverse tunnel through the Home TEP ? Otherwise how does 
the home TEP do the mapping ?
If it sends packets directly in its foriegn domain, the incoming
IPv4 packets ( coming into the home domain) will be received by
the TEP and it will have no idea how to map them.
This is a similar problem to what we try to address in our
proposal for combining SIIT and DSTM.
Maybe the TEP needs to have a similar client to be able to
request this mapping information from the AIIH server.

Do you agree ?

Cheers,
Hesham

---

From: Jim Bound <[email-masked]>
Date: Fri, 15 Sep 2000 14:03:26 -0400

Hesham,

I am catching up on all this DSTM mail.  Nice to see it.  Right now I am
spending most of my IETF cycles on the Base API and DHCPv6 and have to
do that as author and editor for those specs.

Let me put your mind at ease.  I have solutions for the DOS issues and
routing issues you and Erik will be able to use.  And Georges MIP spec
too.

I will ressurect the AIIH parts taken out of DSTM and I am not clear if
Francis and my other co-authors will be part of that or not.  AIIH will
exist for IPv6 (parts taken out of DSTM) as it solves many problems as
you know for real IPv6 deployment we must have.

If we can't do this in the IETF we just implement it and do
informational RFC with any health warnings or take it to 3GPP or
elsewhere for their processes via ITU and ETSI.  The other option is we
build a private vendor consortia and provide public domain code base as
reference base.  But I agree with you if we can solve most of the
problem with AIIH we should do so as proper product engineering for IPv6
transition.  What we can't do is spend another two years discussing this
in IETF meetings and mail lists.  I know I am not alone and many vendors
are down right sick of it as IPv6 customers are showing up at our door
now in Europe and Asia.   The U.S. will move slower but our Education
and U.S. Military entities in the U.S. are taking IPv6 deployment very
seriously, and some of our large Corporate enterprises that want their
global addresses back for network computing for their businesses as NAT
is breaking too much stuff and they need total end-to-end computing.
Which IPv6 can support.

But I can't even think about sending out any text till late October. I
am just to busy and I think my prirority to work on the Base API and
DHCPv6 is correct and for this community too.

regards,
/jim

---

From: Francis Dupont <[email-masked]>
Date: Sat, 16 Sep 2000 13:06:55 +0200

In your previous mail you wrote:

=> I still don't understand what is this IPv4/IPv6 mapping.

   Even in the other case where there is DSTM at home, If the
   IPv6 node is in the foreign domain, does it not still need
   to reverse tunnel through the Home TEP ?

=> this is no reverse tunnel but the TEP-MN IPv4 over IPv6 tunnel is
bidirectional (it is a key point of DSTM, the infrastructure doesn't
need to know how to route IPv4 packets).

   If it sends packets directly in its foreign domain, the incoming
   IPv4 packets ( coming into the home domain) will be received by
   the TEP and it will have no idea how to map them.

=> the packets are sent through the tunnel to the TEP then the TEP
can look at them and discover/manage tunnel parameters (including
MN IPv4 and (home) IPv6 addresses). This is needed by scenario 1
if the AIIH server doesn't configure the TEP (and this is the option
we've implemented).

=> the best solution in your case should to have the AIIH server
configuring both the TEP and the MN. It will be needed by the scenario 2 too.

Regards

[email-masked]