[ppml] Policy Proposal 2005-9: 4-Byte AS Number - revised text

[Member Services]

Policy Proposal 2005-9: 4-Byte AS Number has been revised by the
author. This proposal is open for discussion on this mailing list
and will be on the agenda at the upcoming ARIN Public Policy
Meeting.

The current policy proposal text is provided below and is also available
at: http://www.arin.net/policy/proposals/2005_9.html

Regards,

Member Services
American Registry for Internet Numbers (ARIN)

### * ###

Policy Proposal 2005-9: 4-Byte AS Number

Author: Geoff Huston

Proposal Version: Revision 1 (February 3, 2006)

Proposal type: modify

Policy term: temporary

Policy statement:

      This policy proposal nominates 3 dates for changes to the current
AS Number allocation policy for the registry:

      - Commencing 1 January 2007 the registry will process applications
that specifically request 32-bit only AS Numbers and allocate such AS
numbers as requested by the applicant. In the absence of any specific
request for a 32-bit only AS Number, a 16-bit only AS Number will be
allocated by the registry.

      - Commencing 1 January 2009 the registry will process applications
that specifically request 16-bit only AS Numbers and allocate such AS
Numbers as requested by the applicant. In the absence of any specific
request for a 16-bit only AS Number, a 32-bit only AS Number will be
allocated by the registry.

      - Commencing 1 January 2010 the registry will cease to make any
distinction between 16-bit only AS Numbers and 32-bit only AS Numbers,
and will operate AS number allocations from an undifferentiated 32-bit
AS Number allocation pool.

      Nomenclature

      It is proposed to identify 32-bit AS Numbers using a syntax
of "<high order 16 bit value in decimal>.<low order 16 bit value
in decimal>". Accordingly, a 32-bit AS number of value 65546
(decimal) would be identified as "1.10".

      Terminology

      "16-bit only AS Numbers" refers to AS numbers in the range 0 - 65535

      "32-bit only AS Numbers" refers to AS Numbers in the range 1.0 -
65535.65535 (decimal range 65,536 - 4,294,967,295)

      "32-bit AS Numbers" refers to AS Numbers in the range 0.0 -
65535.65535 (decimal range 0 - 4,294,967,295)


Rationale:

      Recent studies of AS number consumption rates indicate that the
existing 16-bit pool of unallocated AS Numbers will be exhausted
sometime in the period between 2010 and 2016, absent of any concerted
efforts of recovery of already-allocated AS Numbers [1] [2].
Standardization work in the IETF has produced a document that is
currently being submitted as a Proposed Standard that will expand the AS
Number space to a 32-bit field [3].

      It is noted that some advance period may be required by network
operators to undertake the appropriate procedures relating to support of
32-bit AS numbers, and while no flag day is required in the transition
to the longer AS Number field, it is recognised that a prudent course of
action is to allow for allocation of these extended AS numbers well in
advance of an anticipated 16-bit AS Number exhaustion date.

      This policy proposal details a set of actions and associated dates
for RIR AS Number allocation policies to assist in an orderly transition
to use of the 32-bit AS Number space.

      The essential attributes of this policy proposal are to facilitate
the ease of transitional arrangements by equipment vendors, network
managers  and network operations staff, to provide the industry with
some predictability in terms of dates and associated actions with
respect to registry operational procedures for AS Number allocations.

      References

      [1] Daily AS Number Report, http://www.potaroo.net/tools/asns
      [2] ASNs MIA: A Comparision of RIR Statistics and RIS Reality,
http://www.nanog.org/mtg-0510/wilhelm.html
      [3] BGP Support for Four-octet AS Number Space,
draft-ietf-idr-as4bytes-12.txt


Timetable for implementation: Procedures to support this proposal need
to be implemented by 1 January 2007