Post on 21-Jan-2016
27 Mar 2000 IETF IDN-WG 1
Requirements for IDN and its Implementations from Japan
Yoshiro YONEYA <yone@nic.ad.jp>
JPNIC IDN-TF / NTT Software Co.
27 Mar 2000 IETF IDN-WG 2
Contents
• Scope
• Requirements for IDN
• Requirements for IDN Implementations
• Two experimental implementations of JPNIC
• Reference
27 Mar 2000 IETF IDN-WG 3
Scope
• Clarify our Requirements for IDN
• Discuss about Implementations of IDN
Requirements
(Core)Protocol
Domain Name(Structure, etc.)
Implementations
27 Mar 2000 IETF IDN-WG 4
Requirements for IDN
• IDN should be naturally readable and/or writable in its language context– IDN should not require users to specify ZLD– Current ASCII-only Domain Name should be
usable in any language context– But, IDN should not depend on natural
language structure• Word order, word separator, writing direction, etc.
27 Mar 2000 IETF IDN-WG 5
Requirements for IDN (Cont.)
• IDN should be a common framework to make localization easy– Distinguish or unify of differences between characters
should be a local (language depend) issue• Examples in Japanese:
ア (U+FF71) ア (U+30A2) (half-width vs. full-width)A (U+0041) A (U+FF21) (half-width vs. full-width)ア (U+30A2) あ (U+3042) (katakana vs. hiragana)
• Guidelines for each language to deal with such issues should be documented in an RFC– Set of characters usable as IDN label,
canonicalization/normalization rule, etc.
27 Mar 2000 IETF IDN-WG 6
Requirements for IDN (Cont.)
• IDN should have enough length to store long labels– JPNIC in Japanese is 社団法人日本ネットワークイン
フォメーションセンター• Each IDN should have a corresponding ASCII-only
domain name– CNAME / DNAME like aliasing should be used to define
IDN– Reverse mapping should produce 1 or more ASCII-only
name
• IDN character encoding should be stateless– UTF-8 is desirable
27 Mar 2000 IETF IDN-WG 7
Requirements for Implementations
• Internationalization rules should be solved in DNS servers, localization rules should be solved in clients (resolvers)– IDN capable DNS servers should not have regional
dependence• Maintenance supporting tools for IDN capable DNS servers
may have regional dependence
– Conversion of charset and canonicalization and/or normalization should be done on the client side before query
• Proxy servers near clients may do them
27 Mar 2000 IETF IDN-WG 8
Requirements for Implementations (Cont.)
• IDN capable DNS servers should be fully upper compatible with current DNS– Difference should be whether it can hold IDN
• New RRs such as to hold language selector should be examined– Protocol extensions may be needed to
distinguish languages strictly
27 Mar 2000 IETF IDN-WG 9
Requirements for Implementations (Cont.)
• Applications and resolvers should be 8bit through– DNS protocol [RFC1035] is already 8bit through
• Prepare for migration/transition tools and/or proxy servers to prevent initial confusion– URL character code converter, DNS proxy, etc.
– We should discuss about migration/transition strategy like IPv6
27 Mar 2000 IETF IDN-WG 10
Two experimental implementations of JPNIC
• IDNX/idnx-jp– Proxy DNS server– Accepts Japanese local charsets and converts them into
UTF-5– Uses ZLD– Worked well near clients side
• GDNS– 8bit through based on BIND– Uses CNAME for multilingual labels– Not uses ZLD– Worked well even in reverse mapping
27 Mar 2000 IETF IDN-WG 11
Reference
• JPNIC IDN-TF WebPage– http://www.nic.ad.jp/en/research/idn/index.html
27 Mar 2000 IETF IDN-WG 12
Questions?