Compatibility requirements

[Paul Hoffman / IMC <phoffman@imc.org>]

2.1 Backwards compatibility

     The DNS is essential to the entire Internet. Therefore,
     implementation of idn must not damage present DNS interoperability.
     It must (should?) do minimum amount of changes to existing
        ^^^^^^^^^^^^^^ I think "MUST" is appropriate here.
     protocols on all layers of the stack. It must continue to allow any
     system anywhere to resolves any domain names.

     The same request should generate the same response, regardless of
             ^ name resolution
     the location (or localisation settings) of the resolver, the master
     server and any slave or caching servers involved.
Are "master server" and "slave or caching servers" defined anywhere? If
not, I think they should be removed. It is the job of the resolver to
resolve the name the same regardless of the environment.

     It should be possible to build a caching server which does not
     understand the language set in which a request (or response) is
     encoded, and which works as well for IDNs as in the ASCII-only
     case.
Again the question of the definition of a "caching server". Also,
I have never seen the term "language set". I cannot understand what
this requirement means; can we delete it or combine the meaning in
the previous one?

4. Compatibility

This section should be part of 2.1.

     Total compatibility with all existing standards and software which
     is related to domain names cannot be achieved.
I don't like mixing "standards" and "software" in this sentence. There
are proposals for internationalized DNS that maintain total compatibility
with existing standards. Of course, none could be compatible with
existing software. I propose that this be changed to "The best solution
is one that maintains complete compatibility with current DNS standards
as long as it meets the other requirements in this document."

     "Each one of these protocols have to be reviewed and updated given
     the result of this wg. I would like to say that starting with DNS,
     and then go through the protocols."
I have no idea what this means.

I suggest (again) the following requirements for backwards compatibility:

There can be no "flag days" nor a split DNS.

Adding internationalization should add no new centralized
administration for the DNS. A domain administrator should be able to
create internationalized names as easily as adding RFC 1035 names.


--Paul Hoffman, Director
--Internet Mail Consortium