Re: NATs *ARE* evil!

At 02:54 PM 12/14/00 -0500, Tony Dal Santo wrote:
> What exactly is the state of the IPv4 "address pool"?  I realize there is
> a PERCEIVED shortage, and this is usually the main motivation for NAT.
> But is there a real shortage?  Are "reasonable" requests for addresses
> being denied?
The way I understand it (which could easily be out of date) is that about 
45% of the address pool has been delegated, and about 25.21% is currently 
being advertised. The unicast address pool, what we once called the class 
A, class B, and class C address pools, represents 7/8 of the IP Addresses: 
the remainder are divided among the multicast (class D) and experimental 
(class E) address space.
So the bottom line is that we have delegated out a touch over half the 
usable unicast IP Address space. The way we are using that is, in many 
places, interconnecting NAT translation points - the use of private address 
space hides the real usage, and we have no really good way to estimate it. 
If we start going for non-client-server protocols - voice on IP - in a big 
way (and I am told that some of the world's largest telephone carriers have 
plans in place to convert national and international telco backbones to 
VoIP over the coming 3-5 years), that means that these devices will need to 
be addressable from outside their domains, which means those people will 
find themselves needing a non-NAT'd address. Implications are largely 
speculative, but have the option of being non-pretty.
Next question, not usually discussed, is how much of the world as yet 
doesn't have IP Addresses allocated to it and would like to. I think it is 
fair to say that the world is convinced that IP connectivity is very 
important. I have heard ministers of telecom from dirt-poor African 
countries discuss how wonderful it would be to have so much free capital 
laying around that they could "put a telephone into each village." Those 
same ministers are doing whatever it takes to ensure that their countries 
are on the Internet.
Unfortunately, the world is not internet-attached. Western Europe is, the 
US and Canada are, Australia is, Taiwan has Internet in every public 
library (I'm told). It comprises populations in the 1 billion person 
ballpark. There are some pretty large swaths of people in Eastern Europe, 
Asia, and Africa that are not connected and should be. If 25% of the 
address space is what we need for the part connected now, that tells me 
that I need 150% of the address space to cover everybody. If wide 
deployment of converged networks means that 25% was nowhere close enough 
for the present Internet population, then 150% is a very low guess.
So that's "what is" last I heard it from those who have the hard numbers, 
and "what could be". "What will be" remains anybody's guess. My crystal 
ball is really shiny due to excessive rubbing, and just as cloudy as ever.