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MULTILINGUAL DOMAIN NAMES
Hirofumi Hotta
JOINT ITU/WIPO SYMPOSIUM
December 6, 2001
http:// 日本レジストリサービス .jp
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ASCII characters in the Internet
• The Internet as the birth– Born in the United States– Research and academic users
• Limited resources in computers and communication devices– Only ASCII codes are used for the core of the Internet
Only ASCII characters have been usedeven by people using non-ASCII characters in social life
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Ex) non-English characters in e-mail
• Step1– Phonetic mapping in e-mail texts
• Step2– Native language characters in e-mail texts
• Step3– Native language characters in “Subject” fields
• Step4 ?– Native language characters in “To” and “From” field
• Names such as company names and personal names in the social relevant context should be presented in their native language
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What is a domain name ?
• Human readable identifier of an entity within the Internet : Ex) www.itu.int
• Substitute of an IP address
www.itu.int
each label < 63 charactersdomain name < 255 characters
top level domain label
second level domain label
third level domain label
domain name
==
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Domain name structure
“ ”
com
sunyahoo
org jp
co or go
uk au
ad
jprs
int
itu wipo
nic
WWW
WWW
.. ..
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Characters in domain names
• Consumers
• ASCII character set users– Natively ex) English
– In transliterated form ex) Malay
• Non-ASCII character set users– Chinese, Japanese, Korean, Arabic, Tamil, ….
LDHComputer Engineers
Wider users ???
(letters-digits-hyphen)
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Demands on multilingual domain names
• Rapid growth of the Internet– More non-English speakers are becoming Internet users
• People using non-ASCII characters• Undesirable unification in LDH world– 博文 , 博史 , 宏史 , …..are all “hirofumi”s in ASCII space– Apostrophe, accents, umlauts, ….. cannot be used in ASCII space
Demand on multilingual domain names
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History (technology)
• Late 1990s– Multilingual domain names were developed at the Nati
onal University of Singapore
• July 1998– Asia Pacific Networking Group
• iDNS Working group : development of the experimental implementation of an Internationalized multilingual multiscript Domain Names Service– Why shouldn’t domain names be internationalized too, now that
the Internet has grown to reach almost every corner of the world using different languages?
• iDomain Working Group : creation of an iDNS testbed in Asia Pacific countries
• China, Japan, Korea, Hong Kong, Singapore, Taiwan, Thailand, ….
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History (technology) - continued
• 1998-1999– Prototypes demonstrated in international conferences– BoFs held in international conferences
• APRICOT• INET
– Singapore, China, Hong Kong, Korea, Japan, … expressed interests in implementation
• Nov. 1999– BoF in IETF– IETF Mailing list discussion
• Jan. 2000 -– IDN (Internationalized Domain Name) Working Grou
p in IETF
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History (deployment)
• End of 1999– Several companies began commercialization of the mu
ltilingual domain name technology– Several testbeds emerged
• July 2000 - – MINC (Multilingual Domain Names Consortium)
• promotion of the multilingualization of Internet names, including Internet domain names and keywords, the internationalization of Internet names standards and protocols, technical coordination, and liaison with other international bodies
– Country/regional organizations• AINC (Arabic Internet Names Consortium)• CDNC (Chinese Domain Name Consortium )• INFITT (International Forum for IT in Tamil )• JDNA (Japanese Domain Names Association )
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History (policy)
• March 2001– Internationalized Domain Name (IDN) Working Group in
ICANN Board• Fact finding survey concerning technical, policy, and service aspec
ts• Survey report published in Sept. 2001
– Market demand shown– List of issues elaborated
– GAC (Governmental Advisory Committee) of ICANN• communiqué expressing GAC’s support for multilingual domain
names– With regard to international domain names, the GAC confirms the i
mportance and interests of this development to the benefit of Internet users worldwide
• Sept. 2001– IDN Committee
• Will recommend solutions of non-technical issues
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How domain names are resolved
IP address of .com name serverIP address of .int name serverIP address of .jp name server :
IP address of itu.int name serverIP address of wipo.int name server :
root server
.int name server
IP address of www.itu.intIP address of intra.itu.int :
A server having www.itu.int
itu.int name server
intend to browse http://www.itu.int
managed by IANA
managed by ITU
managed by IANAon behalf of .int
http port
Internet
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156.106.192.32
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Where multilingual domain names are recognized
DNS
serverapplicationclient
applicationuser
Internet
currently ASCII domain names
ASCII domain names
multilingual domain names
application
multilingual domain namesoption 1
option 2
in the future
PC
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Key technical questions
• How should non-ASCII codes be represented ? <Q1>• Where should non-ASCII codes be recognized ? <Q2>– in the client application / in the DNS server
• What is the technical mechanism that maps multilingual domain names to current DNS technology ? <Q3>
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Basic technical requirements
• Preservation of compatibility with current domain names
• Preservation of uniqueness of domain name space
• The Internet must not be divided into islands
Required by IAB (Internet Architecture Board)
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Character codes of multilingual domain names
• Current : proprietary (local) standard– in PCs– in PDAs– in Internet-enabled phones
• Best current solution may be– UNICODE – Specification of code sets of many languages
• Additional issues– traditional Chinese characters / simplified Chinese ch
aracters• Are they same characters in domain names ?• Is this a local code issue or universal protocol issue ?
<Q1>
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Client-side vs. Server-side solutions
• Client-side solution– Translation between multilingual script and ASCII-
compatible representation is performed in the user application
– Domain names are processed as ASCII domain names all over the Internet
• Server-side solution– Domain names are sent over the Internet in local
encoding– Applications and services communicate with each
other using non-ASCII domain names all the way
ASCII domain names
multilingual domain names
multilingual domain namesclient-sidesolution
server-sidesolution
user application DNS
<Q2>
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Client-side solution > Server-side solution
• IETF is moving towards client-side solution
• Stability– DNS is a huge distributed database– DNS is working on a delicate balance– Substantial change of DNS is dangerous
• Deployment speed– Changing all the servers takes long time
• Consistency– Partial deployment of server-side solution may lead to separat
ion of the Internet
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How multilingual string is converted to ASCII
original string
normalizedstring
ASCIIstring
Internet(based on ASCII)
unification of the strings considered to be the same
conversion to an ASCII string
NAMEPREP
ACE
ABC カンパニー .JPABCカンパニー .JPA B Cカンハ゜ニー .JP
ABC カンパニー .JP
BQ--GD7UD72C75B2X46RZP6A.JP
ex)
ex)
ex)
<Q3>
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NAMEPREP and ACE
• NAMEPREP (Preparation of Internationalized Host Names)– Multilingual string representations which should be regarded as the same string
are converted into one representation• Case fold• Normalize• Prohibit
• ACE (ASCII Compatible Encoding)– Multilingual representation is converted into an appropriate ASCII domain name– Ex) ACE algorithm
• RACE– BQ--3BS6KZZMRKPDBSJQ4EYKIMHTKQGU7CY
• AMC-ACE-Z– ZQ--ECKWD4C7CU47R2WFQW7A0ECL32K
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Issues in using ACE
• Subspace is used by multilingual domain names
• Issues– Reservation of the subspace– Length limitation is severer
• Domain label• Domain name
ASCII Domain Names
ACE-ed Multilingual Domain Names
Multilingual Domain Names
ACE
decode
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IDNA
user
internalrepresentation
UI
API
application servers
end system
application
local
international
resolver
DNS servers
NAMEPREPTo/From Unicode
To/From ACE
NAMEPREP
to/from ACE
to/from Unicode
(Internationalizing Host Names in Applications)
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Impact on the DNS structure
• Alternate root
Hierarchy overseen
by ICANN
multilingual domain name
space
multilingual domain name
space
NameServer
NameServer
NameServer
TLDs not authorized by ICANN
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authoritative root
multilingualized
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Impact on the DNS structure (continued)
• Inclusive root (variation of alternate root)
Hierarchy overseen
by ICANN
multilingual domain name
space
NameServer
unauthorized TLDs can be seen together with ICANN’s
multilingualized
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Impact on the DNS structure (continued)
• Pseudo-root (zero level domain)
multilingual domain name
space
NameServer
Hierarchy overseen by ICANN
銀行 . 企業 .jp
append “.jp” to “ 銀行 . 企業”
jp
企業
銀行
銀行 . 企業
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Defining a multilingual top level domain
• Current implementation of multilingual domain names– Second level domain or under
• Allowed by current DNS architecture and technology
– Top level domain• Alternate root• Inclusive root• Pseudo-root
• Above are only to satisfy commercial drive or users’ demands on early deployment of multilingual domain names
• It is important for ICANN to define a multilingual top level domain creation policy
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Issues in various TLDs• {non-ASCII-string}.{ASCII-ccTLD}• {non-ASCII-string}.{ASCII-gTLD}– Organizations already being authorized are responsible for the domain name space
• {any-string}.{non-ASCII-ccTLD}– One organization from the relevant country is named to be responsible for the domain
name space– If a country has more than 1 official language,
• What is the language for non-ASCII-ccTLD, or• How many non-ASCII-ccTLDs are given to the country
• {any-string}.{non-ASCII-gTLD}– No one can tell whether top level domain “. 企業” is Chinese or Japanese– Difficulty in choosing a responsible organization
• who in what country
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Other political issues• What are the languages that constitute multilingual domain names– Some languages have 2 or more kinds of scripts– Traditional Chinese/simplified Chinese
• Who is the language authority for multilingual domain names– Should rules be the same even under different TLDs?
• A single domain name registry should not be the ultimate authority of for the rules• Is such rule definition an international issue?
– Language rules are known to only people using the language• To what extent does the solution need international standard or local coordination?• Each language stakeholders should coordinate among themselves
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Implementations
• VGRS (VeriSign Global Registry Services)• JPNIC/JPRS (Japan Network Information Center / Japan Registry
Service)• i-DNS.net• CNNIC (China Internet Network Information Center)• Walid• Neteka• NativeNames
::
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Future Issues
synergydeployment of name servers
with multilingualdomain names
growth of the number of multilingualdomain names and their users
applications with
multilingualdomain name
facilities
policy and coordination of registration and management rules
technology standardization and development
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