At 01:33 PM 3/06/2006, Steven Blake wrote:
I am concerned about the conclusion reached in this document (that HD
ratios > 0.8 and closer to 0.94 should be considered when making address
allocations to larger providers).
This is a topic of interest both to the IETF and to regional addressing
policy fora, and some care needs to be taken in reaching an understanding
of relative roles.
As compared to your opening statement relating to the conclusion of this
document, I must correct you by noting that this document makes NO
specific recommendation as to an optimal HD Ratio value to be used in the
context of a threshold address utilization efficiency metric. This document
provides a refinement to the work reported in RFC1715, RFC 3177 and RFC
3194 that recommended the use of an HD Ratio of 0.8 for assessment of
threshold address utilization efficiencies in an address allocation
context. The refinement proposed in this document is, and I quote:
"This study concludes that consideration should be given to the
viability of specifying a higher HD-Ratio value as representing a
more relevant model of internal network structure, internal routing
and internal address aggregation structures in the context of IPv6
Your representation as to the document's conclusions is simply not
supported by the document itself.
I believe that:
(1) this would not solve a real problem,
I must disagree with this perspective.
This document observes that there is a body of opinion and some evidence
that suggests that the conclusions and recommendations in RFC1715 and
3177, using a metric defined in RFC3194, may not be altogether appropriate
in the context of deployment of public Internet infrastructure. I am of the
view, that yes, this is a topic worthy of some further study and associated
reporting of this perspective.
(2) it is risky to infer too much from existing network design
practice when considering future provider networks that may
be much larger, and
As this document concludes by pointing out that this is an area for further
study it is hard to see where this comment and the document differ
(3) there is a better solution to the alleged problem.
This document does not represent a "solution". Whether you believe that
there is a "better" address utilization threshold efficiency metric than
the HD Ratio, or not, is not exactly the major point of this document. This
document points out that there is a body of evidence that suggests that use
of an HD Ratio of 0.8 is a poor metric and that its is an area for further
study to determine what an appropriate metric may be.
As to where such a study may be conducted, my above observation about the
relative roles of the IETF and regional addressing policy fora was intended
to illustrate the perspective that such a topic may well be best conducted
not in the IETF but in these addressing policy fora. Accordingly, I
strongly suspect that the remainder of your comments may well be best
presented in these fora rather than the IETF.
Ietf mailing list