[ppml] Policy Proposal 2005-9: 4-Byte AS Number - revised text
At 06:04 AM 4/02/2006, Marshall Eubanks wrote:
>Could you possibly send to the list a diff with the previous version ?
There are only 4 changes that have been applied - as noted below
Policy Proposal 2005-9: 4-Byte AS Number
Author: Geoff Huston
Proposal Version: Revision 1 (February 3, 2006)
Proposal type: modify
Policy term: temporary
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
Global change "On 1 January" to "Commencing 1 January
| applications that specifically request 32-bit only AS Numbers
Global change "4-byte" to "32-bit"
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
global change "2-byte" to "16-bit"
- 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
- 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.
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
global change ":" to "."
decimal>". Accordingly, a 32-bit AS number of value 65546
(decimal) would be identified as "1.10".
"16-bit only AS Numbers" refers to AS numbers in the range 0 -
"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)
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
 . 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
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.
 Daily AS Number Report, http://www.potaroo.net/tools/asns
 ASNs MIA: A Comparision of RIR Statistics and RIS Reality,
 BGP Support for Four-octet AS Number Space,
Timetable for implementation:
Procedures to support this proposal need to be implemented by 1