Internationalization of Domain Names

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Internationalization of Domain Names

• James Seng ltjseng_at_i-dns.netgt
• CTO, i-DNS.net International
• co-chair, IETF IDN Working Group

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Internationalized Domain Names

• ??.??.cn ??.??.tw
• ???.??.jp
• ??.??.kr ??.??.kr
• ???????.?
• viagénie.qc.ca
• ??????.???
• ????????.???????.???
• ??.com ???.com

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Internet Engineering Task Force

• IETF is a large open international community of
  network designers, operators, vendors, and
  researchers concerned with the evolution of the
  Internet architecture and the smooth operation of
  the Internet.
• It is open to any interested individual.

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IETF IDN Working Group

• Mailing List
• General Discussion idn_at_ops.ietf.org
• To subscribe idn-request_at_ops.ietf.org
• Archive ftp//ops.ietf.org/pub/lists/idn
• Website http//www.i-d-n.net/
• Chair
• James Seng ltjseng_at_pobox.org.sggt
• Marc Blanchet ltMarc.Blanchet_at_viagenie.qc.cagt

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IDN WG Charter

• The goal of the group is to specify the
  requirements for internationalized access to
  domain names and to specify a standards track
  protocol based on the requirements.
• A fundamental requirement in this work is to not
  disturb the current use and operation of the
  domain name system, and for the DNS to continue
  to allow any system anywhere to resolve any
  domain name.
• The group will not address the question of what,
  if any, body should administer or control usage
  of names that use this functionality.

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Confusion

• Language and Script
• A language is a way that human interact
• A script is the written form of a language
• Many written languages share the same script
• Some written languages use more than one script
• Example, ??.com
• is this in Chinese, Japanese or Korean?

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Confusion

• Name and Identifier
• Name is a word or phrase that constitutes the
  distinctive designation of a person or thing
• Identifier is a string of characters that
  uniquely identify a person or thing
• Example
• James Seng is a Name
• jseng is an Identifier
• is jseng.com a Name or Identifer?
• Domain Name is an Identifier not a Name

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Confusion

• Internationalization, Localization and
  Multilingualism
• Internationalizing make the protocol able to
  handle more scripts
• Localization involves tailoring interaction with
  users in the languages they know
• Multilingualisam makes the protocol able to
  handle multiple languages
• I in IDN is Internationalization

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Problems
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Problems

• Stability
• IDN is changing a fundamental service in the
  Internet Architecture
• Backward Compatibility
• A lot of existing Internet Protocols,
  applications uses domain names and assumed that
  it is A-Z, 0-9 and - only
• Easy of Use
• It should transparent to user if possible

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Problems

• Internationalization
• Using one universal character set or multiples
  characters set?
• What encoding to use? UTF-8? UTF-16?
• Matching
• yahoo.com YAHOO.com
• ??.com ??.com ?

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Work in Progress

• Agreed that ISO10646/Unicode would be the base
  character set for IDN
• ASCII Compatible Encoding (ACE)
• A transformation encoding scheme of ISO10646
  which resultant string is in LDH (Letter,
  Digital, Hypen).
• Limited compression to produce shorter ACE
• AMC-ACE-Z draft-ietf-idn-amc-ace-z-01
• e.g. ???.com zq--3bs3aw5wpa2a.com

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Work in Progress

• Nameprep/Stringprep
• draft-ietf-idn-nameprep
• Based on UTR15 (Normalization) UTR22 (Case
  Mapping) with additional prohibited codepoint and
  folding rules
• Precise and well-defined rules to normalization
  IDN before it is used
• Allows accurate matching of IDN

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Work in Progress

• Internationalized Host Names in Applications
  (IDNA)
• draft-ietf-idn-idna
• IDNA only upgrade in applications to handle IDN
• Consideration of legacy encoding and
  interopability
• Enforce Nameprep in applications
• Uses Nameprep-ACEed IDN over the wire

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Work in Progress

• IDNA-Nameprep-ACE Model

Users
Application
Resolver
DNS
User Interface
No defined encoding, probably local or utf-8
No defined encoding, probably native Unicode
Namepreped AMC-Z
Nameprep-AMC
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Outstanding issues

• Localization
• draft-ietf-idn-tsconv Traditional/Simplified
  Chinese
• draft-ietf-idn-hangeulchar Hangeul
  normalization
• draft-ietf-idn-jpchar Japanese issues
• Enhanced efficiency of ACE
• draft-ietf-idn-lsb-ace Reordering

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Conclusion

• Many confusions
• Took us many months to understand the issues
• Many problems
• No solution is perfect
• Engineering compromised
• Culture consideration
• Many feel very strongly about their own languages
  (but IDN cant handle language)

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Lastly

• IDN Working Group have been around for nearly 20
  months
• Direction have become clearer and there are
  strong support around various solutions
• It is coming!
• Join the working group if you are interested!
• idn-request_at_ops.ietf.org with the word subscribe

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