At 9:41 -0400 4/25/00, Steven M. Bellovin wrote:
>In message <[EMAIL PROTECTED]>, Graham
>Klyne wri
>tes:
>>At 11:06 PM 4/23/00 -0500, Richard Shockey wrote:
>>>With "always on" IP and IP on anything this is closer to reality than we
>>>might think. In order to permit a reasonable allocation of addresses with
>>>room for growth the idea of 25 IP address per household and 10 person
>>>actually seems conservative.
>>
>>Following this line of thought, I'd suggest taking the number of electrical
>>outlets and multiplying by some suitable constant (say, 10, or 1000).
>>
>>And what about all those little wireless-connected gadgets; an IP address
>>for each TV remote-control (where everyone has their own, of course, for
>>personalized access and prioritizing control conflicts...)
>
>I've been in rooms where people have walked through exactly calculation.
>Let's throw a few numbers around.
>
>Assume that the average person in the world has 1000 outlets. That's
>preposterously large for even Bill Gates' house, I suspect, and it doesn't
>even account for dividing by the number of people per house. But let's stick
>with 1000. Assume that there are 25*10^9 people in the world -- 4x the
>current population. And allocate 10 IP addresses for each of those outlets.
>That means that we need a minimum of 25*10^9 IP addresses, plus allowances
>for
>delegation on TLA boundaries, smaller provider chunks, homes, etc.
>
>So -- when I divide 2^128 by 25*10^9, I get ~2^80. That's right -- 80 bits
>worth of address space for allocation inefficiencies. If, at each of three
>levels, we really use just one address out of every 2^16, we *still* have
>32 bits left over.
Doesn't this leave out a few pieces of data? Given the current IPv6
address format, which includes a globally unique 64 bit interface ID and 64
bits of globally unique routing goop. My calculation is that you only have
2^64 addresses to work with which leaves roughly 12 bits, maybe 14 to work
with.
But still, should be more than enough, don't you think?
