Re: [idn] host name vs. domain name

["David R. Conrad" <David.Conrad@nominum.com>]

Hi,

> I agree that there is a distinction between the two and that in order to
> minimize confusion this distinction should be maintained. But I am not
> so sure that it is entirely important for the purposes of what this
> working group seeks to achieve.

I figure it is actually critical to what the working group is trying to
achieve, if you assume the WG is trying to facilitate the use of non-US-ASCII
labels in the operational domain name system.

Again, the domain name system protocols, as designed, are capable of
supporting non-US-ASCII labels -- that is, "domain names" can be much more
than "a-z", "A-Z", "0-9", and "-" (and, with a minor mod to the most common
name server software, this can actually be implemented).  The problem is that
"host names", not "domain names" are what some very significant protocols
expect and violating that expectation will have not insignificant
implications.

If the point of the working group is to "internationalize" domain names, we
should declare victory and move on -- it is (almost) done now.  If the point
of the working group is to allow people to use non-US-ASCII labels in host
names, then there is a lot of work to be done, not least of which are:

- figuring out what encoding to standardize on;
- figuring out how to augment the DNS tree to support those encodings;
- identifying and/or figuring out how to deal with those protocols that are
affected by changes in  host names;

As an aside, my understanding of the "UTF-5"/CIDNUC proposals is they attempt
to avoid the i18n implications by insuring that non-"host name" labels are
encoded in the "host name" character set ("a-z", "A-Z", "0-9", and "-").  The
UTF-8 proposal makes no attempt at avoidance.  As such, it isn't clear to me
from the wording of the draft requirement doc how one could actual meet the
requirements using UTF-8.
 
Rgds,
-drc
Executive Director, ISC