[arin-ppml] Revised - ARIN-2025-6: ARIN-prop-345: Fix formula in 6.5.2.1c

[William Herrin]

On Wed, Sep 3, 2025 at 12:23 PM ARIN <info at arin.net> wrote:
> * ARIN-2025-6: ARIN-prop-345: Fix formula in 6.5.2.1c
>
> Revised text is below and can be found at:
> https://www.arin.net/participate/policy/drafts/2025_6/
>
> Draft Policy 2ARIN-2025-6: ARIN-prop-345: Fix formula in 6.5.2.1c
>
> Problem Statement:
>
> Sections 6.5.2.1 explains the initial IPv6 ISP/LIR allocation in a way that is difficult to follow and the formula in section (c) does not match the remainder of the text.
>
> Policy Statement:
>
> In 6.5.2.1c, replace:
>
> "This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit X is a multiple of 4 greater than 4/3*serving sites and Y is a multiple of 4 greater than 4/3*end sites served by largest serving site."
>
> with:
>
> "This calculation can be summarized as /N where N = P-(X+Y) and P is the organization’s Provider Allocation Unit, X is a multiple of 4 greater than 4/3*log_2(serving sites) and Y is a multiple of 4 greater than 4/3*log_2(end sites served by largest serving site).
>
> In 2.15 and 2.16, replace "provider assignment unit" with "provider allocation unit."
>
> Comments: “Provider assignment unit” in section 2.15 was intended to match “Provider Allocation Unit“ in this policy section, but the words fell out of sync.
>
> Timetable for implementation: Immediatly


ARIN Staff and Legal Review
Date: 9 September 2025
Title: Draft Policy ARIN-2025-6: Fix formula in 6.5.2.1c

Version Reviewed: 3 Sep 2025
(https://lists.arin.net/pipermail/arin-ppml/2025-September/038097.html)

Staff Understanding:

NRPM section “6.5.2.1. Size” describes requirements for the size of
IPv6 allocations to ISPs/LIRs. Sub-section “c” defines how to
calculate the largest allocation justified by the requestor.
Accompanying the text description is a mathematical formula that
intends to summarize the calculation as “/N where N = P-(X+Y) and P is
the organization’s Provider Allocation Unit X is a multiple of 4
greater than 4/3*serving sites and Y is a multiple of 4 greater than
4/3*end sites served by largest serving site.”

This draft policy indicates the formula does not match the text, and
intends to correct it with, "This calculation can be summarized as /N
where N = P-(X+Y) and P is the organization’s Provider Allocation
Unit, X is a multiple of 4 greater than 4/3*log_2(serving sites) and Y
is a multiple of 4 greater than 4/3*log_2(end sites served by largest
serving site).”

ARIN staff currently implements 6.5.2.1.c based on the text alone. The
summarized formula is overly complex for your typical IPv6 requestor.
The text alone is more easily understood by customers and implemented
by ARIN staff. Modifying the formula would have no impact on ARIN
operations. Staff would continue to implement 6.5.2.1.c based on the
text alone. Removing the formula from the NRPM would have no impact on
ARIN operations, and would simplify the policy language for IPv6
requestors.

NRPM section “6.5.2.1. Size” includes the text “Provider Allocation
Unit”, while sections 2.15 and 2.16 reference the term, “Provider
Assignment Unit “. This draft policy intends to update the text in
sections 2.15 and 2.16 to “Provider Allocation Unit”. Modifying
“Assignment” to “Allocation” aligns with the deprecation of Direct
Assignment’s that occurred during ARIN’s fee harmonization. Staff
agrees the terms should match between section 2 and section 6.  Staff
currently considers subnetted Direct Allocations, Reallocations, and
Reassignments to be “Provider Assignment Units”. This modification
aligns with staff’s current implementation.

Implementable as Written?: Yes
Impact on ARIN Registry Operations and Services: None
Legal Review: No material legal issue
Implementation Timeframe Estimate: 3 months
Implementation Requirements:
* Staff Training
* Updates to public documentation





-- 
William Herrin
bill at herrin.us
https://bill.herrin.us/