Subject: RE: Stupid NAT tricks and how to stop them.

From: [email-masked] (Noel Chiappa)
Date: Tue, 28 Mar 2006 13:17:16 -0500 (EST)

> From: "Gray, Eric" <[email-masked]>

    > I think the "street address" analogy is not close enough - anymore
    > than longitude and latitude numbers or any other description of
    > physical location.

No, it's a very good analogy, because the road network is a very good analog
to the data network. To see how, let's do a though-experiment.

Embed the road-network, not on the surface of a solid sphere, but on the
surface of a flexible hollow spherical surface. Now, distort that surface
arbitrarily. The location (in spatial coordinates) of any place on that road
network has changed totally - but the set of directions you'd use to get
from one point in the road network to another ("go down road A until you
meet the junction with B, and turn onto B in the direction of C", etc, etc)
remains unchanged.

What is most important about both the data network, and the road network, is
the *connectivity pattern* - what connects to what. That's because packets
are (usually) constrained to travel down links, and vehicles are (usually)
constrained to travel down roads.

    > The problem with physical location portability is that the location
    > remains even if you're not in it.

But the exact same thing is true of a network - Port #0 on ISP A's router R
is the same place in the network (i.e. you use the same directions to get to
it - see above) whether company X or company Y is plugged in there - just as
126 Main Street is the same building, whether company X or company Y is
housed there.

    > Number assignments, however are substantially more portable.

Saying that doesn't make it so. You can easily (sic) change street names
too, to make a street name "portable".

    > It is certainly possible for an IPv6 address pool manager to allocate
    > personalized IPv6 addresses from an IPv6 address pool that they manage
    > and thereby assume responsibility for end-delivery

That's just a translation service from *virtual* addresses to real ones -
those IPv6 "addresses" aren't the names of locations in the network: if the
pool manager *actually wants to get packets* to those entities, it is going
to have to translate those "addresses" into the real addresses at which
those entities can be found.

	Noel

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From: "JFC (Jefsey) Morfin" <[email-masked]>
Date: Thu, 30 Mar 2006 01:06:25 +0200

Dear Noel,
Let keep the street address analogy. Consider that the full address 
is the addres of the rooms in the building at a given address. Now 
consider that your building is at the corner of a block and it has a 
door on each street. One on 126 Main Street and another on 27 Second 
Avenue (you will accept to consider that the two roads as two 
different ISPs). The  room numbers are the same whatever the address 
you use. Room 125 at 126 Main Street is also Room 125 at 27 Second 
Avenue. The City zip code stay the same.

I think you are with me until now: this is a good image for IPv6 
addresses including Interface IDs?

Now, consider that in that city one does go by street numbers but by 
building names. As we did for a very long time and many still do. So 
our building is named by the City Registry "Innovation House" - and 
if a day it is scrapped and rebuilt eleswhere everyone will keep 
calling it (the new) "Innovation House" (like for Scotland Yard for 
example). Now, the Room 125 is in "Innovation House" on _both_ 
streets. Obviously the zip code is not changed.

This show you can consider a network numbering as _three_ 
concatenated _orthorgonal_ numbers:
- routing (zip code and street)
- identification (name of the house)
- local subaddres (nr of the room).

If you adopt network topology oriented routing numbers you 
dramatically reduce the routing tables as you show it.
Identification registration is something we know pretty well with the 
DNS and the current 256 or so TLDs.

There are different possible formats, but they make you save a lot of 
numbering space.
Mobility is then addressable as a "follow-me" service the user can control.
jfc

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From: Dave Cridland <[email-masked]>
Date: Thu, 30 Mar 2006 00:28:57 +0100

On Thu Mar 30 00:06:25 2006, JFC (Jefsey) Morfin wrote:
> Now, consider that in that city one does go by street numbers but 
> by building names. As we did for a very long time and many still 
> do. So our building is named by the City Registry "Innovation 
> House" - and if a day it is scrapped and rebuilt eleswhere everyone 
> will keep calling it (the new) "Innovation House" (like for 
> Scotland Yard for example). Now, the Room 125 is in "Innovation 
> House" on _both_ streets. Obviously the zip code is not changed.

Your analogy breaks here on the assumption that this is, and indeed 
needs, to be true for anything but a small number of highly 
specialized service addresses. A company can change address.

As as a minor aside, whilst "Scotland Yard, London", will probably 
arrive at the HQ of the Met, their building is "New Scotland Yard". 
Also, my parents happen to have a house which is formally on two 
streets, both under two numbers, and indeed has multiple postcodes. 
(Four, I think).

Dave.
-- 
           You see things; and you say "Why?"
   But I dream things that never were; and I say "Why not?"
    - George Bernard Shaw

---

From: "JFC (Jefsey) Morfin" <[email-masked]>
Date: Thu, 30 Mar 2006 02:46:12 +0200

>specialized service addresses. A company can change address.

I proposed this to get that response.

The main error IMHO of all the IPv6 numbering is to consider 
eveything has to be the same for everyone. Six global numbering 
systems have been foreseen. RIRs have one. ITU has said they assume 
one. Four others can be used. One for space? One for geography? The 
main reason why all this does not move is that there is no 
competition between those two and may be others. The role of ICANN is 
to foster competition in common interest. IPv6 deployment and 
numbering is now out of IETF, hence to ICANN. If the WSIS has asked 
ITU to take the lead, it is because ICANN has been unable manage ITU 
- and possibly create competition. RIRs are in the same situation as 
NSI when they sold domain names $100 a piece for two years. Would 
IPv6 addresses be much, much cheaper and easy to get, I am sure many 
points of this debate would have been already addressed to permit it.

>arrive at the HQ of the Met, their building is "New Scotland Yard".

You just confirm what I said above. Addresses can physically move - 
in the image of street/IPv6 this is equivalent to a change of ISP.

> streets, both under two numbers, and indeed has multiple postcodes. 

You just describe multihoming.
All the best.
jfc