Fwd: A Direction for IPng
To: big-internet@localhost, iepg@localhost, pip@localhost, ripe@localhost, sip@localhost, tpix@localhost, tuba@localhost
From: IESG Secretary iesg-secretary@localhost
Date: Wed, 08 Sep 1993 19:42:10 -0400
Resent-date: Thu, 09 Sep 1993 11:54:07 +0200
Resent-from: RIPE NCC Staff ncc@localhost
Resent-to: Reseaux IP Europeens ripe-list@localhost
Phill Gross asked me to forward this to you all FYI.
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Date: Tue, 07 Sep 1993 14:02:30 -0400
From: Phill Gross pgross@localhost
To: IETF-Announce :;
Subject: A Direction for IPng
A Direction for IPng
At the Amsterdam IETF meeting, we held a BOF, entitled the "IPDecide BOF",
on the process and progress of the IPng activities.
("IPng" stands for "IP, the next generation". The IPDecide BOF was
chaired by Brian Carpenter. Minutes are available in the IETF directories,
with the file name </ietf/93jul/ipdecide-minutes-93jul.txt>.)
The IPDecide BOF explored several facets of the IPng process, such as
- "What is the basis for choosing the next generation IP (i.e., what
are the technical requirements and decision criteria)."
- "With the advent of CIDR and new, more stringent address assignment
policies, are we comfortable that we truly understand the level of
- "Should the IETF or the marketplace make the final IPng decision".
The BOF was held in a productive atmosphere, but did not achieve what could
be called a clear consensus among the assembled attendees. In fact, despite
its generally productive spirit, it did more to highlight the lack of a firm
direction than to create it.
The IPDecide BOF was followed the next evening by the open IESG plenary.
During this session, the IESG and the assembled attendees discussed the
IPng issues and seemed to arrive at a consensus based on the following
set of bullets presented by the IETF chair:
- "The IETF needs to move toward closure on IPng." That is, the
IETF should take active steps toward a technical decision,
rather than waiting for the "marketplace" to decide.
- "The IESG has the responsibility for developing an IPng
recommendation for the Internet community." That is, the IESG
should provide leadership and take specific actions to help move
the IETF toward a technical decision.
- "The procedures of the recommendation-making process should be
open and published well in advance by the IESG."
- "As a part of the process, the IPng WGs may be given new
milestones and other guidance to aid the IESG."
- "There should be ample opportunity for community comment prior
to final IESG recommendation (e.g., there will be an extended
A Direction For IPng
Building on this consensus, I'd like to announce a set of specific directions
in the IESG that I hope will move us toward timely resolution of many of the
key IPng issues.
The IESG will establish a temporary, ad hoc, "area" to deal specifically
with IPng issues. The charter for this new IESG area is to develop a
recommendation on which, if any, of the current proposals should be adopted
as the "next IP". This recommendation will be submitted to the IESG and to
the Internet community for review. Following an adequate period of review
to surface any community concerns, the IESG will issue a final IPng
recommendation. All of the current IPng-related working groups will be
moved immediately into this new area.
This new area will be headed by two co-Area Directors from within the IESG.
I have asked Allison Mankin (NRL), current Transport Services AD, and Scott
Bradner (Harvard), current Operational Requirements AD, to serve as co-AD's
for this temporary area. I am very pleased to report that they have agreed
to take this important assignment. (Because this is expected to be a
temporary assignment, Scott and Allison will also continue to serve in
their current IESG positions during this period.)
All IETF Areas are now expected to have Area Directorates. For the IPng
Area, a Directorate will be especially important to bring additional
viewpoints into the process. Therefore, I am asking that, as their first
action, Scott and Allison form a specific IPng Directorate to act as a
direction-setting and preliminary review body. The IPng process will
continue to be completely open, and therefore reports and meeting notes
from any IPng Directorate meetings will be published in timely fashion.
Issues Toward IPng Resolution
Two important issues need resolution immediately before we can expect
progress toward an IPng recommendation:
- What is the scope of the effort?
That is, should IPng be limited to solving the well known scaling and
address exhaustion issues; or should IPng also include advanced features
such as resource reservation for real-time traffic?
The argument in favor of considering advanced features is that migration
to a new IP is (hopefully, only!) a once-in-a-generation occurance, and
therefore all advanced features should at least be considered.
Arguments opposed to considering advanced features include the fact that
we may not have time for this level of effort before the scaling and
address exhaustion problems confront us, and that we may not have the
necessary understanding and experience to make all the correct choices
at this time.
- What is the available timeframe?
That is, before we can even begin to make an informed decision about the
scope, we need a better understanding of the urgency and time constraints
Factors that affect the available time include the current rate of address
assignments (which can give us an estimate of when we are currently projected
to run out of addresses), the current policies governing address assignment
(which can give us an understanding of how policies affect the assignment
and utilization rates), the impact of CIDR aggregation, the development
time for IPng, and the time needed to field and migrate to the new IPng.
Therefore, I am asking the new AD's and the Directorate to start
immediately the following specific activities to help guide their
ultimate IPng recommendation:
1. Develop an understanding of the available timeframe, covering at
least the following issues:
- Review Internet growth metrics, such as the current address
assignment and utilization rates. Develop an understanding
of how the new address assignment policies impact the assignment
and utilization rates.
- Review the expected impact of CIDR address aggregation. Develop
an understanding of the expected savings due to CIDR aggregation.
- Develop new technical guidelines for classless Internet
addressing. Specific examples include guidelines for how to
utilize variable length subnet masks, and how to utilize currently
unused Class A and B addresses in a classless fashion in hosts and
- Develop a strong understanding of the time required for the
development, fielding, and migration for a new IP.
- Based on all the above issues,
(a) develop an estimate for how long we have to to develop
and deploy an IPng. This could be a set of estimates based
on best/worst case estimates for how each of the above factors
will affect the available timeframe.
(b) Consider whether more stringent assignment policies might
provide additional time. If so, recommend such policies.
(c) make a recommendation on whether it is worthwhile to mount
a serious effort to reclaim addresses and/or to renumber
significant portions of the Internet.
2. Based on an informed judgement of the time constraints above,
make a recommendation regarding the scope for IPng, i.e., should
IPng consider scaling issues only or advanced topics also.
3. Based on the scope and time constraints, develop a clear and
concise set of technical requirements and decision criteria
for IPng. These should include, but not be limited to, the
criteria outlined in the IESG statement (RFC1380).
4. Based on the decision criteria, scope, and time constraints,
make a recommendation on which of the current IPng candidates
to accept, if any.
Finally, I am asking Scott and Allison to make a detailed report at the
opening plenary of the next IETF meeting in November on the status of
setting up their new area, and on their progress toward organizing the
above work items. In particular, the status of the work items on
timeframe should be fully reported. This will be followed by regular
progress reports to the Internet community, at IETF meetings and
in other appropriate forums.
Please join me in giving Scott and Allison our full cooperation, and in
thanking them for accepting this daunting assignment. I feel confident
that we will now make significant progress on the important IPng issues
facing the Internet community.
P.S. All follow-up discussion of this message should be on the
main IETF mailing list ietf@localhost.
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