--On Friday, October 05, 2012 10:29 +0200 João Damas
<joao(_at_)bondis(_dot_)org> wrote:
...
IMO, this discussion has turned up two ways in which the case
for eliminating the possibility of additional label types
could be made:
(2.1) Demonstrating that simply having the capability defined
and available in principle is somehow harmful.
People here can correct me, as my memory is fuzzy, but binary
labels did cause harm to several deployed implementations.
Don't know if this is just case in favour of natural selection.
Again, I'm not defending binary labels. Many people thought
they were a good idea at the time. But, just as "binary labels
failed" is a good argument for deprecating binary labels but not
a good argument for deprecating label types generally, "binary
labels caused harm" (assuming that is the case) would not be a
basis for inferring that all labels types would cause harm, much
less that retaining the capability for using extended label
types would be harmful.
Just as "some cows are brown and all cows are animals" doesn't
tell you a thing about the color of all animals, "binary labels
were a bad idea and binary labels are an instance of extended
label types" doesn't constitute an argument for deprecating
label types.
(2.2) The WG has consensus on a bright line that defines the
nature of proposals that would require going to DNSng rather
than EDNSx-type extensions to the current model, has concluded
that any extensions or alterations to the label definition of
1034/1035 would require crossing that line, and is prepared to
document that line and get IETF consensus on it (either as
part of this document or one normatively referenced from it).
Pretty much, that is my understanding. It is quite possible
that this has been a position reached over many iterations of
discussions and is not actually documented anywhere.
If there is a bright line, it would definitely benefit the
broader community to be able to see a description and discuss
it. If there is only a general feeling in the WG... well, that
doesn't count for much, especially given the history of
disagreements about what the base DNS specifications say and
what assorted terminology means.
john