Subject: Re: [idn] lowercased hostnames (was: naming syntax rules)

From: Dan Oscarsson <[email-masked]>
Date: Thu, 13 Dec 2001 09:27:39 +0100

>> >It seems that if we are forced to lowercase everything but ASCII for

>> >ACE then we have to always lowercase everything but ASCII regardless

>> >of the encoding that may or may not be used.
>>
>> No. It just shows that the IDNA solution will not always return the
>> true domain name.
>
>Doesn't this break your requirement with case-sensitive hostnames? I
mean,
>if a system or application only has access to ACE (for whatever
reason),
>the the lowercased form is the only form that will ever be available,
and
>any dependancy upon proper case will be violated.
>

Applications only having access to the ACE form of names will only be
able
to match names using the ACE form. Therefore they can never break due
to the original  name contains upper case letters.
The problem is when you use the native character set in your system to
define host names. Then still many applications match case-sensitivly.
IDN does not mean that all applications accessing host names with
non-ASCII
characters will know how to compare them. Just like today, many will
just compare the strings, and they will never be aware of how names
enter/exit
the DNS system. When I start using non-ASCII in my host names they
resolver routines will return native names, not ACE, to the
applications.
Otherwise I doubt ever I can start using non-ASCII in host names as
it is totally unacceptible to have to enter or see ACE anywhere a user
normaly
reads or writes host names.

Apart from the matching of names, a lot of companies see the case of
letters as
very important in their name being part of their identity. They will
want
lookups IP number to name to return the name as they like it written.

    Dan

---

From: "Eric A. Hall" <[email-masked]>
Date: Thu, 13 Dec 2001 08:56:52 -0600

Dan Oscarsson wrote:

> able to match names using the ACE form.

They may be decoding the ACE sequence and using the canonical UCS
characters, and only use ACE for transfer purposes, possibly because the
protocols have not been upgraded, or because negotiation has failed.

In those situations, the accessible range of the unencoded UCS characters
will be restricted to lower case.

> When I start using non-ASCII in my host names they resolver routines
> will return native names, not ACE, to the applications.

Correct. However, if the names were encoded in ACE for transfer purposes,
then only the lowercase characters will be available.

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/