Re: Applying HD Ratio to all IPv4 allocations

["william<at>elan.net" <william () elan net>]

I would change it from requirement for HD Ration to optional choice to 
use HD ratio to determine utilization when requesting additional ips.
Here  is what I would prefer for text for that policy proposal:

--- 
  1. All requests for additional IPv4 address space shall require the 
     efficient utilization of the sum total of all existing allocations 
     including all space reassigned to customers, if any. 

  2. When requesting additional ip blocks ISP Members and other organizations
     with direct ARIN allocations and assigments may choose to have its 
     utilization counted by means of HD Ratio, otherwise RFC2050 utilization
     guidelines should be used by ARIN

  3. The HD ratio is calculated as log(utilized IPv4 addresses) divided
     by log(total addresses in all previous allocations). In this formula, 
     log refers to the natural logarithm.

  4. Efficient Utilization per RFC2050 guidelines requires 80% utilization
     of ip blocks, ARIN will verify this by requesting utilization statistics
     for one or more previously assigned or allocated ip blocks.
---

This way we do not all of a sudden change everything and at the same time
those that want to use HD Ratio would be free to do so. ARIN may also try 
to promote HD ratio if it likes it by informing whoever requests ip block
that they have this choice, etc.

On Mon, 9 Feb 2004 Michael.Dillon () radianz com wrote:

> I'm going to present the following policy change at the ARIN
> meeting in April. In a few days I have to submit the exact wording
> to ARIN and I'm looking for comments before I do this.
> Basically this policy loosens the rigid 80% utilization 
> requirement in a progressive fashion to recognize the
> inevitable overhead of hierarchy in larger networks.
>
> 1. All requests for additional IPv4 address space shall require the 
>    efficient utilization of the sum total of all existing allocations 
>    including all space reassigned to customers, if any.
>
> 2. The HD(Host Density) ratio of the sum total of all previous allocations 
>
>    shall be greater than or equal to .966 and the HD ratio of the most 
>    recent allocation shall be greater than or equal to .930 in order to 
>    receive additional space.
>
> 3. The HD ratio is calculated as log(utilized IPv4 addresses) divided
>    by log(total addresses in all previous allocations). In this formula, 
>    log refers to the natural logarithm.
>
> Rationale: 
>
> The HD ratio was proposed as a way to determine allocation usage 
> thresholds
> for IPv6 address allocations. For more details on this, please refer to 
> RFC 3194 <http://www.faqs.org/rfcs/rfc3194.html>. There is some detailed 
> background discussion about applying the HD ratio to IPv4 allocations in a 
>
> proposal by Paul Wilson posted to the APNIC mailing list on Aug 7, 2003 
>
> http://www.apnic.net/mailing-lists/sig-policy/archive/2003/08/msg00000.html
> and he presented the it to the annual APNIC policy meeting using these 
> slides
> http://www.apnic.net/meetings/16/programme/sigs/docs/policy/addpol-pres-wilson-hd-ratio.pdf
> I am not suggesting that ARIN should adopt the APNIC proposal and although
> Paul invents a new name for the HD ratio, I prefer to keep the original 
> term.
>
> The basic thrust of this proposal is to replace the rigid 80% usage 
> criterion 
> by the more flexible HD ratio and to shift the emphasis away from the last 
>
> allocated block to include the total allocated address space. To that end, 
>
> the .930 criterion for the last block is a lot looser than the existing 
> requirements for the last block. This is because the utilization threshold 
>
> establishes a time buffer between the beginning of an ARIN application for 
>
> additional addresses and the final deployment of new addresses in the 
> operational network. By using a looser criterion as network size grows, we 
>
> are also expanding this time buffer. This recognizes that the economy is 
> more dependent than ever on the smooth running of our networks and we 
> should not artificially force larger members to operate with virtually 
> no safety buffers for implementing new addresses. This safety buffer size 
> is important because larger networks have more involved processes for 
> changes to their network and these processes take time.
>
> Paul Wilson's paper contains ample discussions of the technical 
> justification 
> for using the HD ratio. I have proposed that we use the .966 number that 
> he 
> suggests, I believe there may be valid arguments for reducing this 
> slightly, 
> perhaps to .960.
>
> -------------------------------------------------------
> Michael Dillon
> Capacity Planning, Prescot St., London, UK
> Mobile: +44 7900 823 672    Internet: michael.dillon () radianz com
> Phone: +44 20 7650 9493    Fax: +44 20 7650 9030