JOINT ITU/WIPO SYMPOSIUM
MULTILINGUAL DOMAIN NAMES
December 6, 2001
Hirofumi Hotta
hotta@jprs.jp
http://日本レジストリサービス.jp
1
1,2
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 used
even by people using non-ASCII characters in social life
2
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
3
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
domain name
top level domain label
second level domain label
third level domain label
each label <= 63 characters
domain name =< 255 characters
4
Domain name structure
“”
com
org
co
jp
or
.. uk
go
au
ad
itu
yahoo sun
nic
jprs
int
..
wipo
WWW
WWW
5
Characters in domain names
Computer Engineers
LDH (letters-digits-hyphen)
Wider users
• Consumers
• ASCII character set users
– Natively
– In transliterated form
???
ex) English
ex) Malay
• Non-ASCII character set users
– Chinese, Japanese, Korean, Arabic, Tamil, ….
6
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
7
3
History (technology)
• Late 1990s
– Multilingual domain names were developed at the
National 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, ….
8
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
Group in IETF
9
History (deployment)
• End of 1999
– Several companies began commercialization of the
multilingual 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 )
10
History (policy)
• March 2001
– Internationalized Domain Name (IDN) Working
Group in ICANN Board
• Fact finding survey concerning technical, policy, and service
aspects
• 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 importance and interests of this development to the benefit
of Internet users worldwide
• Sept. 2001
– IDN Committee
• Will recommend solutions of non-technical issues
11
4
How domain names are resolved
managed
by IANA
Internet
managed
by IANA
on behalf
of .int
managed
by ITU
root server
IP address of .com name server
IP address of .int name server
IP address of .jp name server
:
.int name server
IP address of itu.int name server
IP address of wipo.int name server
:
itu.int name server
IP address of www.itu.int
IP address of intra.itu.int
：
A server having www.itu.int
http port
intend to browse
http://www.itu.int
156.106.192.32
12
Where multilingual domain names are
recognized
Internet
application
user
server
application
client
application
DNS
PC
currently
ASCII domain names
in the future
option 1 multilingual domain names
option 2
ASCII domain names
multilingual domain names
13
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>
14
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)
15
Character codes of multilingual domain
names
<Q1>
• 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
characters
• Are they same characters in domain names ?
• Is this a local code issue or universal protocol issue ?
16
Client-side vs. Server-side solutions
• Client-side solution
<Q2>
– Translation between multilingual script and ASCIIcompatible 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
user
application
DNS
ASCII domain names
client-side multilingual domain names
solution
multilingual domain names
server-side
solution
17
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
separation of the Internet
18
How multilingual string is converted to
ASCII
ex)
ABCカンパニー.JP
ＡＢＣｶﾝﾊﾟﾆｰ.JP
ＡBＣカンハ゜ニー.JP
original
string
<Q3>
NAMEPREP
unification of the strings considered to be the same
normalized
string
ex)
ABCカンパニー.JP
ACE
conversion to an ASCII string
Internet
(based on ASCII)
ASCII
string
ex)
BQ--GD7UD72C75B2X46RZP6A.JP
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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
20
Issues in using ACE
• Subspace is used by multilingual domain names
ACE
Multilingual
decode
Domain Names
ACE-ed
Multilingual
Domain Names
ASCII Domain Names
• Issues
– Reservation of the subspace
– Length limitation is severer
• Domain label
• Domain name
21
IDNA
(Internationalizing Host Names in Applications)
local
user
application
end system
UI
internal
representation
resolver
international DNS servers
To/From
to/from Unicode
NAMEPREP
To/From
to/from ACE
API
application servers
22
5
Impact on the DNS structure
• Alternate root
multilingualized
Name
Server
Name
Server
Name
Server
multilingual
domain name
space
multilingual
domain name
space
authoritative root
Hierarchy
overseen
by ICANN
TLDs not authorized by ICANN
23
Impact on the DNS structure (continued)
• Inclusive root (variation of alternate root)
multilingualized
Name
Server
Hierarchy
overseen
by ICANN
multilingual
domain name
space
unauthorized TLDs can be
seen together with ICANN’s
24
Impact on the DNS structure (continued)
• Pseudo-root (zero level domain)
銀行.企業
Name
Server
Hierarchy
overseen
by ICANN
append “.jp” to “銀行.企業”
jp
企業
銀行
multilingual
domain name
space
25
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
26
6
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
27
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 28
7
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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8
Future Issues
growth of the number of multilingual
domain names and their users
deployment of
name servers synergy
with multilingual
domain names
applications
with
multilingual
domain name
facilities
policy and coordination of registration and management rules
technology standardization and development
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