[arin-ppml] Policy discussion - Method of calculating utilization

[Jimmy Hess]

On Fri, May 2, 2014 at 7:33 PM, John Santos <JOHN at egh.com> wrote:
> On Fri, 2 May 2014, Jimmy Hess wrote:

> I think 95% is too high, if the previous example of 3 /24's at 100% and
> 1 /24 at 75% is realistic.  That works out to 93.75% aggregate utilization,
> not quite reaching the bar, so 90% might be a better threshold.

For 3 /24s   yes.      The difficulty here, is trying to pick a single
utilization proportion that works regardless   of the aggregate
allocation size, to allow for the loss of the oddball /26 or /27 that
can neither be returned nor reused,    perhaps another method is in
order  than presuming a single   aggregate utilization criterion  is
the most proper.


The more resources you are allocated,  the more opportunity to make
your resource allocation efficient.    By the time you get down to a
/26,   an entire  /24 is less than 0.4%.

Aggregate Resources Allocated                     Required Aggregate
Utilization criterion
more than a /25                                                75%
more than a /22,                                               80%
more than a /20                                                85%
more than a /19                                                90%
more than a /18                                                95%
more than a /17                                                97%
more than a /16                                                98%
more than a /15                                                99%



>
> OTOH, /24's are pretty small and maybe that example was just for
> illustration.  If people really in this situation have much larger
> allocations, they would be easier to slice and dice and thus use (relatively)
> efficiently.  75% of a /24 leaves just 64 addresses (a /26) unused, which
> even if contiguous are hard to redeploy for some other use.  75% of a /16
> would leave 16384 unused addresses, which could be utilized much more easily.
>
>
> Personally, I don't much care since my company has its /24, and that's
> probably all the IPv4 we'll ever need :-)
>
>
> --
> John Santos
> Evans Griffiths & Hart, Inc.
> 781-861-0670 ext 539
>



-- 
-JH