IETF IDN Working Group Sung Jae Shim
Internet Draft DualName, Inc.
Document: draft-ietf-idn-vidn-00.txt 14 November 2000
Expires: 14 May 2001
Virtually Internationalized Domain Names (VIDN)
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
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1. Abstract
This document describes a method that internationalizes existing as
well as future domain names in English, not making any change to the
current DNS, not requiring separate name server or resolver, and not
creating domain names in non-English languages. Based upon the
knowledge of transliteration between a local language and English,
the method allows a user to use virtual domain names in the user's
preferred local language by converting them into the corresponding
actual domain names in English that comply with the current DNS. The
conversion takes place automatically and transparently in the user's
applications before DNS queries are sent. The method uses the current
DNS as it is and meets all the requirements of internationalized
domain names as described in Wenzel and Seng [2].
2. Conventions and definitions used in this document
The key words "REQUIRED" and "MAY" in this document are to be
interpreted as described in RFC-2119 [1].
A "host" is a computer or device attached to the Internet. A "user
host" is a computer or device with which a user is connected to the
Virtually Internationalized Domain Names November 2000
Internet, and a "user" is a person who uses a user host. A "server
host" is a computer or device that provides services to user hosts.
An "entity" is an organization or individual that has a domain name
registered with the DNS.
A "local language" is a language other than English that a user
prefers to use in a local context.
A "virtual domain name" is a domain name in a local language, and it
is not registered with the DNS but used for the convenience of a
user. An "actual domain name" is a domain name in English, and it is
actually used in the DNS. A "domain name" refers to an actual domain
name in English that complies with the DNS, unless specified
otherwise.
A "coded portion" is a pre-coded portion of a domain name (e.g.,
generic organization codes including `com', `edu', `gov', `int',
`mil', `net', `org', and country codes such as `kr', `jp', and so
on). An "entity-defined portion" is a portion of a domain name, which
is defined by the entity that holds the domain name (e.g.,
organization name, server name, and so on).
The method proposed in this document is called "virtually
internationalized domain names (VIDN)" because it uses virtual domain
names in local languages to internationalize actual domain names in
English that comply with the DNS.
A number of Korean-language characters are used in the original of
this document for examples, which is available from the author upon
request. The software used for Internet-Drafts does not allow using
multilingual characters other than ASCII characters. Thus, this
document may not display Korean-language characters properly,
although it may be comprehensible without the examples using Korean-
language characters. Also, when you open the original of this
document, please select your view encoding type to Korean for Korean-
language characters to be displayed properly.
3. Introduction
Domain names are valuable to Internet users as a main identifier of
hosts on the Internet. The current DNS allows using only English
characters in naming hosts or clusters of hosts on the Internet. More
specifically, the DNS uses only the basic Latin alphabets (case-
insensitive), the decimal digits (0-9) and the hyphen (-) in domain
names. But there is a growing need for internationalized or non-
English domain names. Recognizing this need, various methods have
been proposed to use non-English characters in domain names. But to
date, it seems that no method has met all the requirements of
internationalized domain names as described in Wenzel and Seng [2].
A group of earlier methods has tried to put internationalized domain
names inside some parts of the overall DNS system, using UCS encoding
Virtually Internationalized Domain Names November 2000
schemes. But these methods put too much of a burden on the DNS,
requiring a great deal of work for transition and update of the DNS
components. Another group of earlier methods has tried to build
separate directory services for internationalized domain names or
internationalized keywords. But these methods also require complex
implementation efforts, duplicating much of the work already done for
the DNS. Both the groups of earlier methods have tried to build some
mechanisms inside or outside the DNS and put internationalized domain
names or internationalized keywords there in addition to existing
domain names in English.
Unlike earlier methods that involve a lengthy and costly process of
implementation, VIDN provides a more immediate and less costly
solution to internationalized domain names by focusing on
internationalizing existing as well as future domain names in English
that comply with the current DNS, without actually creating domain
names in local languages. VIDN takes notice of the fact that most
domain names used in regions where English is not widely spoken, have
their entity-defined portions consisting of characters or words in
English as transliterated from characters and words in the respective
local languages. Based upon the knowledge of transliteration between
a local language and English, VIDN allows using virtual domain names
in a local language by converting them into the corresponding actual
domain names in English that comply with the current DNS. VIDN allows
the same domain names to be used not only in English as usual but
also in local languages, without creating additional domain names in
local languages.
4. VIDN method
4.1. Objectives
To date, the methods for internationalized domain names have tried to
create domain names or keywords in local languages one way or another
in addition to existing domain names in English, and put them inside
or outside the DNS, using special encoding schemes or lookup
services. These methods require a lengthy and costly process of
implementation. Even when they are successfully implemented, these
methods may localize the Internet by separating it into groups of
local languages that are less universal than English. Further, these
methods may cause disputes on copyrights, trademarks, and so on in
local contexts, in addition to all those disputes we observe with
current domain names in English. VIDN intends to provide a solution
to the problems of earlier methods, by (1) allowing the same domain
names to be used both in English and local languages, without
creating domain names in local languages, (2) working in applications
at user hosts automatically and transparently before DNS requests are
sent, (3) using the current DNS as it is, without requiring any
additional name server or resolver, and (4) being implemented
immediately with little cost.
4.2. Description
Virtually Internationalized Domain Names November 2000
It is important to note that most domain names used in regions where
English is not widely spoken have their entity-defined portions
consisting of characters or words in English as transliterated from
characters or words in local languages. These transliterated
characters or words in English do not have any meanings in English,
but their originals in local languages before the transliteration
into English have some meanings in local contexts, usually indicating
organization names, brand names, trademarks, and so on. VIDN allows
using these original characters or words in local languages as the
entity-defined portions of virtual domain names in local languages,
by transliterating them into the corresponding entity-defined
portions of actual domain names in English. In this way, VIDN allows
the same domain names in English to be also used virtually in local
languages without actually creating domain names in local languages.
As domain names overlay IP addresses, so virtual domain names in
local languages do actual domain names in English. The relationship
between virtual domain names in a local language and actual domain
names in English can be depicted as:
+---------------------------------+
| User |
+---------------------------------+
| |
+----------------|-----------------------|------------------+
| v (Transliteration) v |
| +---------------------+ | +-----------------------+ |
| | Virtual domain name | | | Actual domain name | |
| | in a local language |--+->| in English | |
| +---------------------+ +-----------------------+ |
| User application | |
+----------------------------------------|------------------+
v
DNS request
VIDN uses the phonemes of a local language and English as a medium in
transliterating the entity-defined portions of virtual domain names
in the local language into those of actual domain names in English.
This process of transliteration can be depicted as:
Local language English
+----------------------------+ +-----------------------------+
| Characters ----> Phonemes -----------> Phonemes ----> Characters |
| | | | | | |
| | | | | | |
| (Inverse of transcription) | Match | (Transcription) |
+----------------------------+ +-----------------------------+
| ^
| (Transliteration) |
+------------------------------------+
First, each entity-defined portion of a virtual domain name in the
local language is decomposed into individual characters or sets of
Virtually Internationalized Domain Names November 2000
characters so that each individual character or set of characters can
represent an individual phoneme of the local language, which is the
inverse of transcription of phonemes into characters. Second, each
individual phoneme of the local language is matched with an
equivalent phoneme of English that has the same or most proximate
sound. Third, each phoneme of English is transcribed into the
corresponding character or set of characters in English. Finally, all
the characters or sets of characters converted into English are
united to compose the corresponding entity-defined portion of an
actual domain name in English.
For example, a word in Korean, `??' that means `century' in English,
is transliterated into `segi' in English, and so, the entity whose
name contains `??' in Korean may have an entity-defined portion of
its domain name as `segi' in English. VIDN allows using `??' in
Korean as an entity-defined portion of a virtual domain name in
Korean, which is converted into `segi' in English, the corresponding
entity-defined portion of an actual domain name in English. More
specifically, the phonemes represented by the characters consisting
of `??' in Korean have the same sounds as the phonemes represented
by the characters consisting of `segi' in English. In the local
context, `??' in Korean is clearly easier to remember and type and
more intuitive and meaningful than `segi' in English.
An entity-defined portion of a virtual domain name in Korean, `??',
is transliterated into `yahoo' in English, since the phonemes
represented by the characters consisting of `??' in Korean have the
same sounds as the phonemes represented by the characters consisting
of `yahoo' in English. That is, `??' in Korean is pronounced as the
same as `yahoo' in English, and so, it is easy for Korean-speaking
people to deduce `??' in Korean as the virtual equivalent of
`yahoo' in English. VIDN allows using virtual domain names in a local
language for domain names whose originals are in the local language,
e.g., `??' in Korean, as well as domain names whose originals are
in English, e.g., `??' in Korean. In this way, VIDN can make domain
names truly international, allowing the same domain names to be used
both in English and local languages.
The coded portions of domain names such as organization codes,
geographic codes and country codes, can also be transliterated from a
local language into English, using the phonemes of the two languages
as a medium. For example, seven generic organization codes in English,
`com', `edu', `gov', `int', `mil', `net', and `org', can be
transliterated from `?', `??', `??', `??', `?', `??', `??' in
Korean, respectively, which can be used as the corresponding
organization codes of virtual domain names in Korean. Based upon its
meaning in English, each coded portion of actual domain names also
can be pre-assigned a virtual equivalent word or code in a local
language. For example, seven generic organization codes in English,
`com', `edu', `gov', `int', `mil', `net', and `org', can be pre-
assigned `??' (meaning `commercial' in Korean), `??' (meaning
`education' in Korean), `??' (meaning `government' in Korean),
`??' (meaning `international' in Korean), `??' (meaning `military'
in Korean), `??' (meaning `network' in Korean), and `??' (meaning
Virtually Internationalized Domain Names November 2000
`organization' in Korean), respectively, which can be used as the
corresponding organization codes of virtual domain names in Korean.
Since VIDN uses the phonemes of a local language and English as a
medium of the transliteration, it does not create such complexities
as other conversion methods based upon semantics do. Further, most
languages have a small number of phonemes. For example, Korean
language has nineteen consonant phonemes and twenty-one vowel
phonemes, and English language has twenty-four consonant phonemes and
twenty vowel phonemes. Each phoneme of Korean language can be matched
with a phoneme of English language that has the same or proximate
sound, and vice versa.
Some characters or sets of characters of a language may represent
more than one phoneme. Also, some phonemes of a language may be
represented by more than one character or set of characters. But
these variations usually occur in particular situations, and so, VIDN
incorporates the special provisions to deal with such variations. In
addition, not every character or set of characters in a local
language may be neatly transliterated into only one character or set
of characters in English. In practice, people often transliterate the
same word in a local language differently into English or vice versa.
VIDN also incorporates the provisions to deal with such variations
caused by common usages or idiomatic expressions. Because of these
variations, however, it is probable for one virtual domain name
entered in a local language to result in more than one actual domain
name in English.
VIDN includes a coding scheme in order to make each virtual domain
name entered in a local language correspond to exactly one actual
domain name in English. In this coding scheme, a unique code is pre-
assigned to one of the corresponding actual domain names in English
for each virtual domain name to be entered in a local language. The
code is kept somewhere at the server host that has the actual domain
name in English, for example, in the main HTML document at the server
host, so that VIDN can check the code. VIDN also generates the same
unique code whenever the corresponding virtual domain name is entered
in user applications. Then, VIDN checks whether the code at each
server host matches with the code generated in user applications. If
one of the server hosts has the code that matches with the code
generated in user applications, VIDN recognizes that the virtual
domain name entered by the user corresponds only to the actual domain
name of that server host, and connects the user host to the server
host. The domain names of the remaining server hosts that do not have
the matching code may be listed to the user as alternative sites. For
security purpose, this coding scheme may use an encryption technique.
For example, `??.?', a virtual domain name entered in Korean, may
result in four corresponding domain names in English including
`jungang.com', `joongang.com,' `chungang.com', and `choongang.com',
since the phonemes represented by characters consisting of `??.?'
in Korean can have the same or almost the same sounds as the phonemes
represented by characters consisting of `jungang.com',
`joongang.com,' `chungang.com', or `choongang.com' in English. In
Virtually Internationalized Domain Names November 2000
this case, we assume that the server host with its domain name
`jungang.com' has the pre-assigned code that matches with the code
generated when `??.?' in Korean is entered in user applications.
Then, the user host is connected to this server host, and the other
server hosts may be listed to the user as alternative sites so that
the user can try them.
The process of this coding scheme that makes each virtual domain name
in a local language correspond to only one actual domain name in
English, can be depicted as:
+---------------------------------+
| User |
+---------------------------------+
| |
+----------------|-----------------------|------------------+
| v v |
| +---------------------+ +-----------------------+ |
| | Virtual domain name | | Potential domain names| |
| | in a local language |---->| in English | |
| | e.g., `??.?' | | e.g., `jungang.com' | |
| | (code: 297437)| | `joongang.com' | |
| | | | `chungang.com' | |
| | | | `choongang.com' | |
| +---------------------+ +-----------------------+ |
| User application | |
+----------------------------------------|------------------+
^ |
| | Code check by VIDN
Connection to | | +-- `jungang.com'
the server host | | | (code: 297437)
`jungang.com' | | |-- `joongang.com'
| |----+ (not active)
| | |-- `chungang.com'
| | | (code: 381274)
| DNS request and | +-- `choongang.com'
| response | (not active)
+-----------------------+
Since VIDN converts separately the entity-defined portions and the
coded portions of a virtual domain name, it preserves the current
syntax of domain names, that is, the hierarchical dotted notation,
which Internet users are familiar with. Also, VIDN allows using a
virtual domain name mixed with characters in a local language and
English as the user wishes to, since the conversion takes place on
each individual portion of the domain name and each individual
character or set of characters of the portion.
While VIDN preserves the hierarchical dotted notation of current
domain names, the principles of VIDN are also applicable to domain
names in other possible notations such as those in a natural language
(e.g., `microsoft windows' rather than `windows.microsoft.com'). Also,
the principles of VIDN can be applied into other identifiers used on
the Internet, such as user IDs of e-mail addresses, names of
Virtually Internationalized Domain Names November 2000
directories and folders, names of web pages and files, keywords used
in search engines and directory services, and so on, allowing them to
be used interchangeably in a local language and English, without
creating additional identifiers in the local language. The conversion
of VIDN can be done between any two languages interchangeably. Thus,
even when the DNS accepts and registers domain names in other
languages in addition to English, VIDN can allow using the same
domain names in any two languages by converting virtual domain names
in one language into actual domain names in another language.
4.3. Implementation
In a preferred arrangement, VIDN is implemented in applications at
the user host. That is, the conversion of virtual domain names in a
local language into the corresponding actual domain names in English
takes place at the user host before DNS requests are sent. Thus,
neither a special encoding nor a separate lookup service is needed to
implement VIDN. VIDN is also modularized with each module being used
for conversion of virtual domain names in one local language into the
corresponding actual domain names in English. A user needs only the
module for conversion of his or her preferred local language into
English. Also, VIDN can be implemented at a central server host or a
cluster of local server hosts. A central server with all the language
modules of VIDN can provide the conversion service for all local
languages, or a cluster of local server hosts can share the
conversion service. In the latter case, each local server host with a
language module or a set of language modules can provide the
conversion service for the respective local language or set of local
languages used in a certain region.
Because of its small size, VIDN can be easily embedded into
applications software such as web browser, e-mail software, ftp
system, and so on at the user host, or it can work as an add-on
program to such software. In either case, the only requirement on the
part of the user is to install VIDN or software embedding VIDN at the
user host. Using virtual domain names in a local language in
accordance with the principles of VIDN is very intuitive to those who
speak the local language. The only requirement on the part of the
entity whose server host provides Internet services to user hosts is
to have an actual domain name in English into which a virtual domain
name in a local language is neatly transliterated in accordance with
the principles of VIDN, and to have a pre-assigned code kept at its
server host for one-to-one matching of its actual domain name and a
virtual domain name to be used by users. Most entities in regions
where English is not widely spoken already have such domain names in
English. Finally, there is nothing to change on the part of the DNS,
since VIDN uses the current DNS as it is.
Taken together, the features of VIDN can meet all the requirement of
internationalized domain names as described in Wenzel and Seng [2],
with respect to compatibility and interoperability,
internationalization, canonicalization, and operating issues. Given
the fact that different methods toward internationalized domain names
Virtually Internationalized Domain Names November 2000
confuse users, as already observed in some regions where some of
these methods have already been commercialized, e.g., Korea, it is
important to find and implement the most effective solution to
internationalized domain names as soon as possible.
4.4. Testing results
A testing version of VIDN has been developed for Korean-English
conversion as a web browser add-on program. The program contains all
the features described in this document except the coding scheme.
While the final version of the program is planned to include the
coding scheme, the testing version lists all the domain names in
English that correspond to a virtual domain name entered in Korean so
that a user can choose one. The testing results of a sample of
randomly selected domain names used in Korea show that the program
can cover more than ninety percent of the sample. The results
indicate that more than ninety percent of web sites in Korea can be
accessed using virtual domain names in Korean without creating
additional domain names in Korean. The remaining ten percent of
domain names are mostly those that contain acronyms, abbreviations or
initials. With improvement of its knowledge of transliteration, the
final version of the program is expected to cover most domain names
used in Korea.
5. Security considerations
Because VIDN uses the DNS as it is, it inherits the same security
considerations as the DNS.
6. Intellectual property considerations
It is the intention of DualName, Inc. to submit the VIDN method and
other elements of VIDN software to IETF for review, comment or
standardization.
DualName has applied for one or more patents on the technology
related to virtual domain name software and virtual email software.
If a standard is adopted by IETF and any patents are issued to
DualName with claims that are necessary for practicing the standard,
DualName is prepared to make available, upon written request, a non-
exclusive license under fair, reasonable and non-discriminatory terms
and condition, based on the principle of reciprocity, consistent with
established practice.
7. References
1 Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997
Virtually Internationalized Domain Names November 2000
2 Wenzel, Z. and Seng, J. (Editors), "Requirements of
Internationalized Domain Names," draft-ietf-idn-requirements-
03.txt, August 2000
8. Author's address
Sung Jae Shim
DualName, Inc.
3600 Wilshire Boulevard, Suite 1814
Los Angeles, California 90010
USA
Email: shimsungjae@dualname.com