Subject: draft-duerst-dns-i18n-02.txt

From: Robert Elz <[email-masked]>
Date: Mon, 19 Jul 1999 12:16:12 +0100

Martin,

can you tell us what the current status of draft-duerst-dns-i18n-02.txt is?

I see it as a very old I-D, that appears as if it ought to have expired
some time ago, but is lingering on.

I ask because the DNSIND (soon to become DNSEXT) working group of the
IETF has on its agenda (albeit as a backburner task) questions of
internationalisation of the DNS.   That effort has been largely based
upon Stuart Kwan's draft (draft-skwan-utf8-dns-02.txt).

Your draft has been recently brought to our attention as an alternative
method.

It seems to me that your draft is based upon a misconception of the DNS.
That is, that the DNS is limited to [a-zA-Z0-9-] labels.   That is simply
not true, the DNS can handle any binary stream at all in a label (provided
it can be encoded in no more than 63 octets).    Aside from the questions
of whether it should be done at all (about which we have some continual
disputes), the main questions to deal with are to define exactly how to
interpret the binary stream that can occur in the DNS as characters, how to
deal with the DNS current rules of case independence, and how to ensure that
various domain names can be written in, or converted to, a canonical form
such that security algorithms can validate their accuracy.

Your draft touches upon some of those questions, aside from its encoding
scheme, and its proposed new "ZLD", and is interesting for that.

In particular, you seem content to attempt to remove case independence as
a requirement for internationalised domain names.   Stuart's draft instead
prefers to keep case independence, and does so by requiring that all mixed
case domain names be encoded (in DNS packets) in their lower case forms,
so only the client which desires to perform the lookup need undertstand the
nuances of the character set in question, no servers need have the vaguest
idea (a laudable goal, which your scheme also strives to reach).

This seems to be a clear conflict in goals between the two drafts, and is one
that would be nice to see sorted out - is case independence important or not?

Eg: does it matter to you that your name written DÜRST would not be
treated the same as when it is written as Dürst ?   This was the aim of the
case independence in the DNS, and while it one of the most troublesome
aspects, especially for internationalisation concerns, is it one which
ought be discarded completely (assuming that would be possible, somehow,
with pure ascii names) ?

Finally, given that the DNS really does have no problems with encoding
binary labels, and that representing UTF-8 means no more than simply
making sure that the implementations are bug free, is there anything in
particular about your proposed encoding which you feel would suggest that
it might be superior?

kre

---

From: "Martin J. Duerst" <[email-masked]>
Date: Thu, 22 Jul 1999 14:50:57 +0900

Hello Robert,

Many thanks for contacting me. A group in Singapore has
taken up my proposal, see e.g. http://www.apng.org/idns/
for more info. They have a mailing list, and a new version
of my draft should be submitted fairly soon. This group
also had an apparently fairly successful BOF at the last
INET conference (Patrick Faltstrom, IETF Apps Area Director,
was there).

At 12:16 99/07/19 +0100, Robert Elz wrote:
> internationalisation of the DNS.

I very much hope that this can be taken from the backburner to the
frontburner (or whatever you call it).

> That effort has been largely based

I have seen that work, and I think it's a much better way to go
in the long term. The people working on my draft like it because
some things are easier in the short term. I think the IETF should
clearly give the task of solving these problems to a WG, and have
the WG discuss issues of short-term and long-term deployment,...

> it can be encoded in no more than 63 octets).    

No. I was aware of that. I just made a proposal for how to deal with it
under the restrictions of all the systems surrounding the DNS. It was
mostly a strawman proposal which successfully silenced some of the
doubts brought against URI internationalization.

> Aside from the questions
> disputes), 

Of course it should be done.

> the main questions to deal with are to define exactly how to
> interpret the binary stream that can occur in the DNS as characters,

My preference is clearly UTF-8.

> how to
> deal with the DNS current rules of case independence,

I think the Kwan draft has some reasonable suggestions.

> and how to ensure that

What would you want to canonicalize?

> idea (a laudable goal, which your scheme also strives to reach).

There may be some trademark issues (i.e. NeXT), but otherwise I think Stuart's
proposal is fine.

> Eg: does it matter to you that your name written D$B%o(JRST would not be
> treated the same as when it is written as D$B—S(Jst ?   This was the aim of the

Not from my side. But the group in Singapore already has quite a lot
of deployment experiment experience. I think it would be good for you
to discuss that with them, on the [email-masked] list or wherever
appropriate.

Thanks again for contacting me, and please keep in touch,   Martin.

#-#-#  Martin J. Du"rst, World Wide Web Consortium
#-#-#  mailto:[email-masked]   http://www.w3.org