|
Internet
Draft
Authors: Xiang
Deng
<draft-ietf-idn-icdn-00.txt> Yan Fang Wang July , 2001 Expires in six months The Implementation of Chinese character in IDN Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task
Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed
at
http://www.ietf.org/ietf/1id-abstracts.txt The list of Internet-Draft Shadow Directories can be
accessed at
http://www.ietf.org/shadow.html Terminology
The key words "MUST", "SHALL", "REQUIRED", "SHOULD", "RECOMMENDED",
and
"MAY" in this document are to be interpreted as described in RFC 2119 [RFC2119]. Abstract
This document mainly talks about Chinese characters and two proposed
schemes of implemention based on [IDNREQ] and [NAMEPREP],though there are some differences among them.The distinction between these two schemes is the position of the implementation function: -- client side processing or -- server side processing In China, the most popular character set are
[GBK],[BIG5],[GB18030],while
in this document,all examples are based on [UCS]. |
Internet Draft Authors: Xiang Deng
<draft-ietf-idn-icdn-00.txt> Yan Fang Wang
July , 2001
Expires in six months
The Implementation of Chinese character in IDN
Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Task
Force (IETF), its areas, and its working groups. Note that other groups
may also distribute working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference material
or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html
Terminology
The key words "MUST", "SHALL", "REQUIRED", "SHOULD", "RECOMMENDED", and
"MAY" in this document are to be interpreted as described in RFC 2119
[RFC2119].
Abstract
This document mainly talks about Chinese characters and two proposed
schemes of implemention based on [IDNREQ] and [NAMEPREP],though
there are some differences among them.The distinction between these two schemes
is the position of the implementation function:
-- client side processing
or
-- server side processing
In China, the most popular character set are [GBK],[BIG5],[GB18030],while
in this document,all examples are based on [UCS].
1. Charateristics of Chinese characters and Chinese languange
1.1 The context dependent semantics of Chinese characters
In [UCS],each Chinese character is a codepoint,which is composed of two
bytes.
Chinese character can be classified as two groups. In one group,each
character does its own meaning(notional character) while that of the
other group has not(empty characters). Both notional characters and
empty characters can be made words by combining with other
character(s),even sentences. the notional character
is the basic unit of Chinese language which has meaning similar to phonems.
1.2 A Chinese characters may have several writing forms.
Chinese characters were continuously evolved and widely spread during
5,000-year-long Chinese history. They were also largely introduced
into other countries and became a major component of their languages.
Therefore, it is inevitably for a Chinese character has many other
writing forms. In Unicode encoding standards, the criterion for
distributing codepoint is the shape of character. So the different
glyph of the same Chinese character have several different
codepoint according to the international encoding standard.
Currently,there are two forms of writing Chinese character:
-- simplified character(SC): mainland of China
-- traditional character(TC): Taiwan,Hongkong,Macao
Except for some special writing forms of certain character, their
meaning had also been changed in the long history. Generally different
writing forms of a Chinese character can substituted by each other
without changing the meaning of the word(phrase).
1.3 The Usage of Appellation in China
In China, Generally speaking,every companies,organizations and people
have two names: full name and abbreviation.
The abbreviated name is easy to remember and to communicate.The full
name is a formal name which is used in formal document,situation.
To the name owners,the two names are equal necessary and important.
So,in domain name registration,they usually register both full name
and the corresponding abbreviations in order to permit people to access
the same domain name by typing the full name or the abbreviatied name.
Some of the full names are quite long,that's why the length of domain
name is important for Chinese user.
2. Chinese characters in DNS
1.1 Traditional and Simplified Chinese Conversion has 3 forms:
1-1 mapping: one traditional character(TC) maps to ONLY one simplified
characer(SC).
1-n mapping: one TC has several SC writing forms
n-1 mapping: one SC has several forms of TC
1.2 Delimiter folding
The full stop in chinese is "ĄŁ". Therefore, the "ĄŁ" in CDNS is equal
to the dot "." as the delimiter.
1.3 Label sequence
Currently,the label sequence of LDH domain name is from left to right,
(e.g.:abc.def.ghi.net),the subdomain is to the left and the superset
of the subdomain is to the right.
In China,user has reverse convention of language. Considering the
culture different between the east and the west, it's necessary for
people to access the Internet with the convention of using their native
languages.for example:
CDNLabel1.CDNLabel2.cn
perfer to :
cn.CDNLabel2.CDNLabel1
3. Solutions
3.1 Client side solution
+-----------------------------------------------+
| user input |
+-----------------------------------------------+
| ^
V |
+-------------------+ |
| Delimiter folding | |
| "ĄŁ" -> "." | |
+-------------------+ |
| |
V |
+------------------------------+ +------------------------------+
| label sequence normalization | | label sequence normalization |
+------------------------------+ +------------------------------+
| ^
V |
+----------------------+ +----------------------+
| local encoding ->UCS | | UCS ->local encoding |
+----------------------+ +----------------------+
| ^
V |
+------------------------+ +------------------------+
| local mapping (TC - SC)| | local mapping (TC - SC)|
+------------------------+ +------------------------+
| ^
V |
+----------+ |
| NAMEPREP | |
+----------+ |
| |
V |
+------------+ +-----------------+
| UCS -> MDN | | UTF8/ACE -> UCS |
+------------+ +-----------------+
| ^
V |
+-----------------------------------------------+
| local resolver |
+-----------------------------------------------+
| DNS server |
+-----------------------------------------------+
3.1 Server side solution
+-----------------------------------------------+
| user input |
+-----------------------------------------------+
| ^
V |
+-------------------+ |
| Delimiter folding | |
| "ĄŁ" -> "." | |
+-------------------+ |
| |
V |
+------------------------------+ +------------------------------+
| label sequence normalization | | label sequence normalization |
+------------------------------+ +------------------------------+
| ^
V |
+----------------------+ +----------------------+
| local encoding ->UCS | | UCS ->local encoding |
+----------------------+ +----------------------+
| ^
V |
+----------+ |
| NAMEPREP | |
+----------+ |
| |
V |
+------------+ +-----------------+
| UCS -> MDN | | UTF8/ACE -> UCS |
+------------+ +-----------------+
| ^
V |
+-----------------------------------------------+
| local resolver |
+-----------------------------------------------+
|
V
+-----------------------------------------------+
| local mapping (TC - SC) |
|-----------------------------------------------|
| DNS server |
+-----------------------------------------------+
6 Authors' Address
Xiang Deng
China Internet Network Information Center
NO.4 South 4th ST. Beijing, P.R.China, 100080, PO BOX 349
Tel: +86-10-62619750
Yan Fang Wang
China Internet Network Information Center
NO.4 South 4th ST. Beijing, P.R.China, 100080, PO BOX 349
Tel: +86-10-62619750
7 References
[IDNREQ] Requirements of Internationalized Domain Names, Zita Wenzel,
James Seng, draft-ietf-idn-requirements
[NAMEPREP] Paul Hoffman & Marc Blanchet, Preparation of
Internationalized Host Names, draft-ietf-idn-nameprep
[RFC2119] Scott Bradner, Key words for use in RFCs to Indicate
Requirement Levels, March 1997, RFC 2119.
[STD13] Paul Mockapetris, Domain names - implementation and
specification, November 1987, STD 13 (RFC 1034 and 1035).
[UNAME] Internationalized Domain Names and Unique Identifiers/Names
Li Ming TSENG, Jan Ming HO, Hua Lin QIAN, Kenny HUANG
draft-ietf-idn-uname
[TSCONV] Traditional and Simplified Chinese Conversion
Xiao Dong Lee, Nai Wen Hsu, Erin Chen, Guo Nian Sun
draft-ietf-idn-tsconv
[ISO10646] ISO/IEC 10646-1:2000. International Standard -- Information
technology -- Universal Multiple-Octet Coded Character Set
(UCS) -- Part 1: Architecture and Basic Multilingual Plane.
[Unicode3] The Unicode Consortium, "The Unicode Standard -- Version3.0",
ISBN 0-201-61633-5.