Multilingual Domain Name 22 Feb 2001 YONEYA, Yoshiro JPNIC IDN-TF

22 Feb 2001IWS20012 What is MDN? Multilingual Domain Name. –Current domain name is represented with ASCII alpha-numeric and hyphen characters. Multilingualization of Domain Name is, –Technical challenge to represent domain name with not only ASCII but also NON-ASCII characters. –Almost equivalent to Internationalization of domain name.

22 Feb 2001IWS20013 What is IDN? Internationalized Domain Name. –Framework to multilingualize domain name. –Need to be a Global Standard. –IETF IDN (Internationalized Domain Name) WG is doing the work. –Some confusion by using the word ‘Internationalized’.

22 Feb 2001IWS20014 Why MDN? Increase of the Internet users who are not familiar with English. –Easy to memorize, type in, etc. Drastic change of usage of domain name. –Domain name is now used as not only host name but also signboard. Creates new business opportunities. –Many ventures began services.

22 Feb 2001IWS20015 Drawback of MDN Actually, it is localization. –Loses global acceptability. –Hard to type in or display without appropriate I/O devices. Cause impact to the operation. –Requires software update and / or additional processing. –Deployment issue.

22 Feb 2001IWS20016 Standardization trend of MDN REQUIREMENTS ACE NAMEPREP IDNA

22 Feb 2001IWS20017 Requirements draft-ietf-idn-requirements-04.txt Definition of requirements for MDN. –30 items such as –Interoperability / compatibility with current DNS protocol. –ISO-10646/Unicode for Character set. –Normalization of representation. –Easy to add current domain name space.

22 Feb 2001IWS20018 Requirements Respect to IAB statement. –RFC2825 Preservation compatibility with current domain name. –RFC2826 Preservation of uniqueness of domain name space. –Not to divide the Internet into islands.

22 Feb 2001IWS20019 ACE ASCII Compatible Encoding. Represent NON-ASCII characters by ASCII characters. –Easy to apply current DNS. –Minimize impact to current applications. Decreases maximum characters in each label. –Penalty of using 5bit to represent 8bit data. –Requires some sort of compression algorithm.

22 Feb 2001IWS ACE Requires explicit ACE-identifier. –For reverse conversion. –Choice of ACE-ID is political issue. ACE-ID itself is ASCII string, so that if any proposal for ACE-ID is raised, it will be registered as ASCII domain name. Actually happened at gTLD. –ZLD – Zero Level Domain – such as ‘.I’ is not realistic.

22 Feb 2001IWS ACE Impact to operation. –Configuration file and zone files should be written in ACE. –Therefore, supporting tools such as editor and / or filter are essential. Application solution. –Local encoding at user interface. –ACE at network interface.

22 Feb 2001IWS ACE Proposed ACEs. –RACE (Row-based ACE) draft-ietf-idn-race-03.txt –BRACE (Bi-mode Row-based ACE) draft-ietf-idn-brace-00.txt –LACE (Length-based ACE) draft-ietf-idn-lace-01.txt –DUDE (Differential Unicode Domain Encoding) draft-ietf-idn-dude-00.txt –AMC-ACE-M draft-ietf-idn-amc-ace-m-00.txt

22 Feb 2001IWS Flow of ACE conversion User 日本語.JP Local App lic ati on Code conv 日本語.JP Unicode Normaliza- tion 日本語.jp (65e5 672c 8a9e.jp) Unicode Compress …00000.jpBit stream BASE323bs6kzzmrkpa.jpACE Networkbq--3bs6kzzmrkpa.jpACE(ID)

22 Feb 2001IWS NAMEPREP Preparation of Internationalized Host Names draft-ietf-idn-nameprep-02.txt Normalization of representation of the same string in meaning or displaying. –Character case (upper, lower), compatible characters (Fullwidth, Halfwidth) –Composed characters Umlaut in German, accent in French, voiced sound in Japanese, etc.

22 Feb 2001IWS NAMEPREP Processes in NAMEPREP 1.map Case folding of upper/lower characters (UTR#21) 2.normalize Normalize representation of string (UTR#15) 3.prohibit Check out inappropriate character as domain name. 4.unassigned Treatment of unassigned characters

22 Feb 2001IWS IDNA Internationalizing Host Names in Applications. Applications do following process. –Character set conversion between local and Unicode. –NAMEPREP. –Character encoding conversion between Unicode and ACE.

22 Feb 2001IWS IDNA Requires adaptation of Application programs. Alternatives are, –Adaptation at resolver. IDNRA – Internationalized Host Names using Resolvers and Applications May work well at name resolution, but might not work within application protocol such as SMTP and HTTP. –Adaptation at DNS server. Requires DNS protocol modification. Hard to deploy due to back bone system replacement.

22 Feb 2001IWS IDNRA User UI Internal Representation Application servers End system Application Local Int’l Resolver DNS servers Resolver DNS servers API

22 Feb 2001IWS IDNA User Internal Representation UI API Application servers End system Application Local Int’l Resolver DNS servers NAMEPREP To/From Unicode To/From ACE NAMEPREP To/From ACE To/From Unicode

22 Feb 2001IWS What is mDNkit? Project of JPNIC –Started on Apr 2000 Multilingual Domain Name evaluation kit –mDNkit-1.x release series Objectives –Evaluation of the MDN technology –Promoting standardization of MDN –Technical contribution to the Internet community

22 Feb 2001IWS Components of mDNkit libmdn –Core library for MDN processing mdnconv –DNS zone / configuration file code converter dnsproxy –DNS query / response code converter runmdn / mDN Wrapper –Dynamic link resolver library for UNIX / Windows BIND 9 patch –MDN enhancements for BIND 9 resolver library

22 Feb 2001IWS Diagram of components libmdn mdnconvdnsproxy named zone file Legacy client Encoding on DNS Protocol (ACE) Local Encoding (SJIS, EUC…) UNIX client Windows client mDN wrapper Multilingualized resolver / runmdn

22 Feb 2001IWS Position of mDNkit User UI Internal Representation Application servers End system Application Local Int’l Resolver DNS servers Resolver DNS servers mDNkit API

22 Feb 2001IWS New features in mDNkit (work in progress) Adopting NAMEPREP Provides local mapping APIs Provides high-level MDN APIs Multilingual Domain Name tool kit –mDNkit-2.x release series Come to be …

22 Feb 2001IWS Diagram of New features in mDNkit User Internal Representation UI API Application servers End system Application Local Int’l Resolver DNS servers Resolver DNS servers NAMEPREP Local Mapping To/From ACE mDNkit High-level APIs Local Mapping To/From ACE NAMEPREP

22 Feb 2001IWS Localization Support proposals to be involved in NAMEPREP in the future –Should be discussed at IETF IDN WG Delimiter mapping –To avoid some harmful behavior Local mapping –To complement NAMEPREP

22 Feb 2001IWS Delimiter mapping Characters that IME converts when ‘.’ is typed in Looks like a domain name, but a single word Ex. ジェーピーニック。 JP (means JPNIC.JP in Japanese) Web Browser sends query to Search Engine DNS clients sends query to Root Server!

22 Feb 2001IWS Local mapping Practically NFKC is sufficient but some exceptions –Depends on mapping table of Unicode and Local charset Map such exceptions onto suitable ones for NFKC –Ex.1 ‘ ゛ ’, ‘ ゜ ’ (Voiced and semi-voiced sound mark in Japanese) Need to map onto combining character “ シ゛ェーヒ゜ーニック ”  “ ジェーピーニック ” –Ex.2 ‘ － ’ (Full-width Hyphen) Need to map onto ASCII hyphen

22 Feb 2001IWS ACE Local UTF-8 APIs Local map ACE Local UTF-8 ACE Code Converter (Local  UTF-8) Delimiter map Code Converter (UTF-8  ACE) Service Servers NAMEPREP Map Normalize Prohibit UI

22 Feb 2001IWS References IETF IDN WG Web page – JPNIC IDN Web page – Unicode Consortium –