[arin-ppml] efficient utilization != needs basis

michael.dillon at bt.com michael.dillon at bt.com
Wed Dec 23 03:28:36 EST 2009

> Some examples are; Smart Grids, emergency response networks, 
> and one that has been functioning from more that a decade is 
> the Automotive Network Exchange (ANX).

ANX is a "community of interest network". There are others.
For instance, SITA operates one for the global air transport
industry and my employer operates one for the global financial
services industry.

> Why do these need globally unique addressing?  
> Globally unique addresses really make thing like the ANX much 
> easier, and there are many other private inter-AS networks 
> that exist today and I only see more and more in the future.

Things like ANX, SITA's network and the BT Radianz Shared Market
Infrastructure, are all internetworks. Just like the public
Internet, these private internets interconnect multiple independent
networks. Just like on the public Internet, these internets
have their own peering with many ASes. Globally unique registered
addresses are essential to manage the complexity of these

> These all have different challenges and I bring them up in 
> this context 
>    because they all also have "operational need" and as we to 
> define a "needs basis" for IPv6, we must find a definition 
> that encompasses the "operational needs" of these other internets too.

Even RFC 2050 recognizes this type of operational need in 
section 3 a)
   the organization has no intention of connecting to the
   Internet-either now or in the future-but it still requires
   a globally unique IP address. The organization should
   consider using reserved addresses from RFC1918. If it is
   determined this is not possible, they can be issued unique
   (if not Internet routable) IP addresses.

The fact is that when you have multiple independent organizations
interconnecting their networks, it doesn't matter whether it
is the public Internet or a private internet that does the
interconnection, RFC1918 addressing is simply not possible.
The addresses in RFC1918 were allocated for "private network"
use, meaning for use in networks which do NOT INTERCONNECT with
other networks.

I think that when people talk about needs basis they are
conflating operational need for a unique globally registered
range, with the justified quantity of addresses that are needed.
Certainly in IPv6, we focus on operational need, i.e. if you
have a unique site, then your operational need justifies a /48
assignment from your ISP. But at the higher levels, we still
evaluate the justified quantity of address space when making
allocations to ISPs.

--Michael Dillon

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