Re: [Int-area] Introducing IPv4 Unicast Extensions with new draft-schoen-intarea-lowest-address

[John Gilmore <[e-mail]>]

> Do I understand correctly, that you are proposing that all hosts,
> routers, firewalls, middle boxes, etc. on the Internet, be updated in
> order to get a single extra IP address per subnet?  ...
> To me this fails the cost benefit analysis.

You may be right (see below).  One confounding factor is that the
lowest-address draft is the first of a set of upcoming drafts that
propose small, easy improvements in IPv4.  This set of changes, in
aggregate, will be worth implementing, because they create hundreds of
millions of newly usable addresses, worth billions of dollars at current
prices.  If the cost-vs-benefit is worth doing for ANY ONE of these
changes, or for any subset of these changes, then the deployment effort
may as well include the other, smaller, improvements, which will come
for very close to free.

I agree that the "lowest address" protocol change is only likely to
produce tens of millions of newly usable addresses, creating only
perhaps $250M to $500M of benefits at current prices.  That alone might
not be worth doing, particularly since predicting FUTURE prices of IPv4
addresses is risky.  But let's look at the costs.  The end-user cost of
updating can be zero because it can be deferred until equipment is
naturally upgraded for other reasons.  Nobody would buy a new router to
get this feature, but eventually almost everybody buys a new router.  Or
installs the latest OS release.  The change is completely compatible
with existing networks, since the lowest addresses are currently not
known to be used for anything and have been declared obsolete in IETF
standards for decades.  This makes the deployment risk very low.

So I expect the main cost would be for each vendor to make and test
small patches to their existing IPv4 implementations, and then include
those changes as part of their next release or product.  Our team
successfully patched both Linux and BSD over a few weeks, and
interoperated them successfully.  Based on that experience, I estimate
implementation costs to major IPv4 vendors to be under $10M in total.
By 5 to 10 years after adoption, the improvement would be everywhere,
and will probably have paid off about 25-to-1.  I agree that the people
incurring the costs of this proposal are not the people who end up
getting the benefit of the IP addresses; the benefit goes to the
vendors' customers, benefiting the vendors indirectly.  So the
cost-benefit tradeoff might be more societal (or network-wide) than
individual or corporate.  My understanding is that IETF's role is as a
steward of network-wide value, which is why I thought this might
interest IETF.

	John Gilmore
	IPv4 Unicast Extensions