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Versions: 00 01                                                         
IDN Working Group                             Edmon Chung & David Leung
Internet Draft                                              Neteka Inc.
<draft-ietf-idn-dnsii-mdnr-01.txt>                        February 2001



               DNSII Multilingual Domain Name Resolution


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 reader is cautioned not to depend on the values that appear in
   examples to be current or complete, since their purpose is primarily
   educational.  Distribution of this memo is unlimited.

   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.

   A copy of this particular draft is also archived at
   http://www.dnsii.org.


Abstract

   This document outlines a resolution process that forms a framework
   for the resolution of multilingual domain names.  Additionally, a
   tunneling mechanism utilizing additional RRs is introduced for the
   transition to a fully multilingual capable name space.

   The Internet-Draft for DNSII-MDNP was focused purely on discussing
   the ultimate packet protocol that is being sent around the Internet
   for multilingual domain names.  This paper complements the previous
   paper by outlining the contemplated resolution process with the DNSII
   protocol throughout the DNS name resolution process.

   Whether the DNSII protocol is implemented exactly as specified in
   DNSII-MDNP is less relevant, rather it is the idea of having a
   multilingual packet identifier and the fall back process that
   matters.  The DNSII-MDNR successfully addresses the transitional
   issues at each node of the DNS resolution process providing a clear
   migration path and strategy for the deployment of a multilingual

DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   enabled DNS system.  It also outlines the conformance levels required
   for basic or complete implementations for applications, resolvers and
   name servers.


Table of Contents

   1. Introduction....................................................2
   1.1 Terminology....................................................2
   1.2 Multilingual Domain Name Resolution............................3
   1.2 DNSII-MDNR.....................................................3
   2. DNSII Proposal with respect to the DNS Layers...................3
   3. The Resolution Process..........................................5
   3.1 Steady State Resolution........................................5
   3.2 Client-End or Inquirer Transitional Fall-Back Strategy.........6
   3.2.1 Tunneling MDNP through DNSII RR..............................6
   3.2.2 Tunneling ILET RRs...........................................8
   3.3 Resolvers & Server-End Transitional Fallback Strategy..........9
   3.3.1 Tunneling MDNP Responses through DNSII ANS RR................9
   3.3.2 Reinsertion of ILET and DNSII Identifier....................10
   4. DNSII Conformance Levels.......................................10
   4.1 Application Conformance Levels................................11
   4.2 Resolver Conformance Levels...................................11
   4.3 Authoritative Server Conformance Levels.......................11
   5. Transition Schedule & Strategy.................................12
   6. Summary of Discussion..........................................12
   6.1 Client/Application Resolution Strategy........................13
   6.2 Resolver Resolution Strategy..................................13
   6.3 Authoritative Name Server Resolution Strategy.................13
   7. Security Considerations........................................14
   8. Intellectual Property Considerations...........................14
   9. References.....................................................14


1. Introduction

   This Internet-Draft describes details of the contemplated resolution
   process after the deployment of DNSII-MDNP, or other multilingual
   domain name efforts containing a bit flag multilingual packet
   identifier or otherwise InPacket identifications for that matter.

   The reader is assumed to be familiar with the concepts discussed in
   the DNSII-MDNP Internet-Draft <draft-ietf-idn-dnsii-mdnp.txt>.


1.1 Terminology

   The key words "MUST", "SHALL", "REQUIRED", "SHOULD", "RECOMMENDED",
   and "MAY" in this document are to be interpreted as described in RFC
   2119 [RFC2119].




DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   A number of multilingual characters are used in this document for
   examples.  Please select your view encoding type to Big-5
   (Traditional Chinese) for them to be displayed properly.




1.2 Multilingual Domain Name Resolution

   The original specifications for the DNS were designed to be open
   enough for simple implementation of a multilingual naming system with
   slight adjustments as laid out in DNSII-MDNP.  The transition and
   especially its resolution process during migration is however a
   tricky problem.  Several things that MUST be kept in mind is that
   there is a initial phase, an intermediate phase and an ultimate
   steady state phase.  DNSII-MDNP only described the ideal protocol at
   steady state, with incorporated flexibility for transition from the
   present to multilingual as well as again towards future unknown
   grounds.

   It is important to remember that the ultimate form SHOULD be
   determined and then the transition scheme laid out.  While an ASCII
   translation system might seem favorable in the short-run, it
   effectively creates an alternative universe which is counter to the
   spirit of the DNS.  However an ASCII translation is implemented, it
   immediately creates a "human-multilingual" universe and a "machine-
   ASCII" universe.  This document introduces a tunneling mechanism to
   transition the DNS from today's monolingual system, through an 8-bit
   or 7-bit migration scheme towards a truly sustainable multilingual
   name space, arriving at a DNSII type system.


1.2 DNSII-MDNR

   While DNSII-MDNP describes the framework for the ultimate protocol
   format of a multilingual DNS, DNSII-MDNR will discuss how the packet
   SHOULD be transported and interpreted throughout the DNS.  The
   document will describe both the intended resolution process as well
   as part of the transition strategy from the existing DNS to a DNSII
   enabled system.


2. DNSII Proposal with respect to the DNS Layers

   The following diagram illustrates the use of DNSII-MDNP at a steady
   state.  Section 3 will discuss the fallback strategies while Section
   4 will talk about issues on conformance levels.







DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   +---------------+
   |               | NamePrep:
   |  Application  | Canonicalize in Form C/KC
   |               | Insert DNSII Identifier    +---------------------+
   |               | Insert appropriate ILET    |    (Base data)      |
   +---------------+                            +---------------------+
           |                                            |
           |  DNS Packet with DNSII                     | (no standard)
           |  Identifier & ILET                         |  RECOMMENDS
           |                                            |  UCS-2/4
   +---------------+                                    |
   |   Resolver    | Canonicalize, Case Fold    +---------------------+
   |               | (for cache lookup) or      | Auth DNS server     |
   +---------------+ leave as is & Resolve      | (Canonicalize,      |
           |                                    | Case Fold & Lookup) |
           |  Pass Along without                +---------------------+
           |  Altering Case or Canonicalization         |
           |                                            |
           |   <-----   DNS service interface  ----->   |
   +------------------------------------------------------------------+
   |  DNS service                                                     |
   |  +-----------------------+         +--------------------+        |
   |  | Forwarding DNS server |         | Caching DNS server |        |
   |  +-----------------------+         +--------------------+        |
   |                                                                  |
   |                 +-------------------------+                      |
   |                 | Parent-zone DNS servers |                      |
   |                 +-------------------------+                      |
   |                                                                  |
   |                 +-------------------------+                      |
   |                 | Root DNS servers        |                      |
   |                 +-------------------------+                      |
   |                                                                  |
   +------------------------------------------------------------------+

   Please note that at each level, the domain name is being
   canonicalized.  This is to ensure that at the end, characters that
   can be represented by a single code point will not be otherwise
   compared resulting in inconsistent reply to a humanly identical name.
   It is RECOMMENDED that applications SHOULD conduct canonicalization
   while servers MUST.  Duplicating the process is fine because if a
   character is already composed, it will not compose again with another
   character.

   This arrangement is very similar to the ASCII case folding
   experienced in the DNS today.  In the original specifications, it was
   RECOMMENDED that query sent be left as they are and case folding done
   only at the server end.  Some application implementations however do
   perform the case folding at the user end.  As the query arrives at
   the server, it is still case folded.




DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   Case folding for multilingual domain names should follow the existing
   implementations for ASCII names, where the application SHOULD and the
   server MUST.


3. The Resolution Process

   It is inevitable that at the end of the day, the entire DNS chain
   SHOULD be updated in order for multilingual domain names to be as
   efficiently resolved as names under the current DNS.  DNSII strives
   to provide a schema that ultimately brings the system to a desirable
   steady state while carefully giving considerations to all the
   transition issues.  These include the considerations that at the
   application end, there is already a preference and an installed base
   of character encoding that may or may not conform to the desires of
   the server end operations.  The use of ILET is therefore highly
   desirable and essential.


3.1 Steady State Resolution

   At steady state, the resolution process of multilingual domain names
   SHOULD be identical to the existing system.  Additional steps of
   going through alphanumeric translation are unnecessary and
   undesirable.

   With DNSII, the contemplated steady state process resembles the well-
   known DNS model laid out in RFC1035.


                   Local Host                          |    Foreign
                                                       |
    +---------+                   +----------+         |  +---------+
    |         | user queries      |          |queries  |  |         |
    |         |(DNSII identifier  |          |         |  |         |
    |         | ILET=UCS without  |          |         |  |         |
    |  User   | Transformation)   |          |         |  | Foreign |
    | Program |------------------>| Resolver |---------|->| Name    |
    |         |                   |          |         |  | Server  |
    |         |<------------------|          |<--------|--|         |
    |         | user responses    |          |responses|  |         |
    |         |                   |          |         |  |         |
    +---------+                   +----------+         |  +---------+
                                    |     ^            |
                    cache additions |     | references |
                                    v     |            |
                                  +----------+         |
                                  |  cache   |         |
                                  +----------+         |


   Eventually, an ISO 10646 UCS without transformation is desired as the
   common format.  The benefits of having a uniform byte length encoding

DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   far exceeds the seemingly easier transformation solution.  Especially
   considering that the DNS requires a label count that should reflect
   the number of characters in a label.  Of course there exists
   combination characters in the ISO 10646 specifications as well, but
   after canonicalization, only the ones that must use combinations
   remain and they are usually meaningful depictions.

   The importance of this count value is further demonstrated by
   scrambling efforts to extend the size of this field or to compress
   character encoding to accommodate multilingual characters.  With
   DNSII, this no longer constitutes an issue because any language will
   be able to share the same number of characters thanks to the use of
   ISO 10646.  As a matter of fact, the desire to use uniform byte
   length characters formed part of the original intent of the ISO 10646
   initiative anyway.

3.2 Client-End or Inquirer Transitional Fall-Back Strategy

   For a DNSII aware Client, it will be able to create DNSII packets
   which provides precise character data of the domain name in question.
   However, if it encounters a non-compliant resolver, it MUST be able
   to fallback to a format acceptable by current resolvers.


    +---------+                        +----------+
    |         | (1) user queries       |          | (2) if Resolver is
    |         | (DNSII identifier      |          |  DNSII compliant,
    |         |  ILET=UCS without      |          |  Packet is resolved
    |  User   |  Transformation)       |          |  accordingly.  If
    | Program |----------------------->| Resolver |  not fallback to (3)
    |         |                        |          |
    |         |<-----------------------|          |
    |         | (3) Upon the detection |          |
    |         |  of the DNSII Flag     |          |
    |         |  resolver will reply   |          |
    |         |  with _Format Error_   |          |
    |         |                        |          |
    |         |----------------------->|          | (5) Current resolu-
    |         | (4) Send QNAME using   |          |  tion process begins
    |         |  local encoding or     |          |  with the DNSII RR
    |         |  UTF-8 with or without |          |  passed along as an
    |         |  Additional DNSII RR   |          |  Additional RR
    +---------+                        +----------+


3.2.1 Tunneling MDNP through DNSII RR

   An additional DNSII RR would be tunneled through using the format of
   a TXT RR with the RDATA part containing the multilingual labels in a
   DNSII compliant format.  The TTL of the RR MUST be set to zero to
   avoid caching.



DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   It is not feasible to have a new RR type just for DNSII because the
   resolver might reject RRs with unknown types.  For the name used in
   the QNAME as well as the NAME field of the DNSII RR UTF-8 MAY be used
   as the default fallback encoding.  However, an arbitrary ASCII name
   MAY also be used just for the purpose of tunneling.  The TTL for
   responses to tunneled requests MUST be set to zero to avoid caching
   at any level in the DNS.  More detailed description in Section 3.4.

   For older DNS servers, requests with a non-empty additional
   information section MAY produce error returns, however since the
   deployment of DNSSEC, especially for TSIG considerations, this no-
   longer constitutes a problem.  Basic security prepared servers such
   as BIND 4 or 8 is already capable of bearing the tunneled DNSII RR.

   It is possible to use ACE/RACE type translations at this level,
   however it is more advisable to use a truly arbitrary label such as
   _-for-tunneling-only-_.  So doing requires only reserving one
   arbitrary name while ACE/RACE creates one more arbitrary name for
   each new multilingual name registered, which will eventually
   contribute to the fracturing of the DNS.

   As an example, a tunneling packet for the domain name: host. —ŒªW¿t™ð
   .tld. (4host4—ŒªW¿t™ð3 tld0) will be represented as:

   (in the QNAME field)

                          1 1 1 1 1 1                     1 1 1 1 1 1
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
     +---------------------------------------------------------------+
   12|0 0|     4     |       h       |       o       |       s       |
     +---------------------------------------------------------------+
   16|       t       |      20       |       -       |       f       |
     +---------------------------------------------------------------+
   20|       0       |       r       |       -       |       t       |
     +---------------------------------------------------------------+
   24|       u       |       n       |       n       |       e       |
     +---------------------------------------------------------------+
   28|       l       |       i       |       n       |       g       |
     +---------------------------------------------------------------+
   32|       -       |       o       |       n       |       l       |
     +---------------------------------------------------------------+
   36|       y       |       -       |       3       |       t       |
     +---------------------------------------------------------------+
   40|       l       |       d       |       0       |...
     +-----------------------------------------------+









DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   (The Additional DNSII RR Tunneled in TXT RR form)

      :                                                               :
      /                                                               /
      +---------------------------------------------------------------+
    80|1 1|             12            |        TYPE = TXT = 16        |
      +---------------------------------------------------------------+
    84|        CLASS = IN = 1         |              TTL              |
      +---------------------------------------------------------------+
    88|              = 0              |        RDLENGTH = 22          |
      +---------------------------------------------------------------+
    92|0 0|     4     |       h       |       o       |       s       |
      +---------------------------------------------------------------+
    96|       t       |1 0|0 0|       UCS-2=1000      |       4       |
      +---------------------------------------------------------------+
   100|1 1|             13            |1 0|z|  ILET=2 |       4       |
      +---------------------------------------------------------------+
   104|          —Œ   (U+57DF)        |          ªW    (U+540D)         |
      +---------------------------------------------------------------+
   108|          ¿t   (U+7CFB)        |          ™ð    (U+7D71)         |
      +---------------------------------------------------------------+
   112|1 1|             38            |
      +-------------------------------+


   The reason a DNSII RR is attached is to alert the authoritative DNS
   server that the query is DNSII compliant while being able to tunnel
   the request through non-compliant resolvers without any loss of
   information.

3.2.2 Tunneling ILET RRs

   Another fallback strategy is to tunnel just the ILET instead of the
   entire DNSII label.  If UTF-8 or a local encoding is used as the
   QNAME, then the arbitrary ASCII label is no longer necessary.  The
   tunneled RR therefore need only consist of an ILET indicating the
   encoding format used.

   Within the RDATA of an ILET RR masked as a TXT RR the first 4 bytes
   will be used to indicate that it is an ILET and the following 4 bytes
   to reflect the MIBenum of the encoding used.













DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   Following the example given in 3.2.1, the QNAME would be in UTF-8
   (MIBenum = 106), while the additional ILET RR would be in the form:

      :                                                               :
      /                                                               /
      +---------------------------------------------------------------+
    80|1 1|             12            |        TYPE = TXT = 16        |
      +---------------------------------------------------------------+
    84|        CLASS = IN = 1         |              TTL              |
      +---------------------------------------------------------------+
    88|              = 0              |        RDLENGTH = 22          |
      +---------------------------------------------------------------+
    92|       I       |       L       |       E       |       T       |
      +---------------------------------------------------------------+
    96|       0       |       1       |       0       |       6       |
      +---------------------------------------------------------------+


3.3 Resolvers & Server-End Transitional Fallback Strategy

   The tunneling scheme described in Section 3.2 assumes that the
   authoritative server is fully DNSII compliant.  This assertion is
   laid out in Section 4.3 where it is discussed that only fully
   compliant servers SHOULD serve multilingual names directly under
   their authoritative zone.  In any other case, the arbitrary domain
   "-for-tunneling-only-" should result in an NXDomain response.

   For security aware servers, an NXT RR of the last name wrapped by its
   first name in the zone records will be returned because of the
   leading "-" for the tunneling label.

   If the application end is not DNSII compliant, the fallback
   resolution strategy for resolvers would simply be to pass along the
   labels in their 8-bit format and determine the existence of the
   requested name as usual.  If a tunneled DNSII RR is detected, by way
   of a label constituting entirely of _-for-tunneling-only-_ and the
   existence of a valid DNSII RR, the resolver should attempt to resolve
   the name according to the DNSII specification and tunnel the answer
   back to the inquirer.


3.3.1 Tunneling MDNP Responses through DNSII ANS RR

   To tunnel a DNSII compliant answer through a non-compliant resolver,
   another DNSII ANS RR is tunneled.  Also using the TXT RR format as a
   mask.  TXT RRs are best used because it is a valid RR and its RDATA
   is an unrestricted byte stream determined only by the RDLENGTH.  The
   RDATA for a DNSII ANS RR would be the entire content of a regular
   response RR attached to a DNSII format name.

   Continuing on the example given in Section 3.2, suppose an A record
   is requested and the IP address returned for the domain host.—ŒªW¿t™ð


DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   .tld. is 123.4.5.6, then an additional DNSII ANS RR (TXT) in the
   following form will be included:

      :                                                               :
      /                                                               /
      +---------------------------------------------------------------+
   114|1 1|             12            |        TYPE = TXT = 16        |
      +---------------------------------------------------------------+
   118|        CLASS = IN = 1         |              TTL              |
      +---------------------------------------------------------------+
   122|              = 0              |         RDLENGTH = 16         |
      +---------------------------------------------------------------+
   126|1 1|             92            |          TYPE = A = 1         |
      +---------------------------------------------------------------+
   130|        CLASS = IN = 1         |              TTL              |
      +---------------------------------------------------------------+
   134|            = 3600             |         RDLENGTH = 4          |
      +---------------------------------------------------------------+
   138|      123      |       4       |       5       |       6       |
      +---------------------------------------------------------------+

   Note that compression is available in the DNSII RRs.  While the
   tunneling TXT mask uses the ASCII tunneling name and therefore points
   back to the QNAME at offset 12, the tunneled A Record response uses
   the offset corresponding to the DNSII compliant labels at 92.  While
   the TTL of the TXT mask MUST be zero, the tunneled A Record RR
   contains a regular TTL, in this case 3600.


3.3.2 Reinsertion of ILET and DNSII Identifier

   When a resolver receives an incoming query with a tunneled DNSII/ILET
   RR, it SHOULD reconfigure the query into a fully compliant format
   before engaging in further resolution.  If a "00" query is received,
   the resolver should convert the label into UTF-8, set the DNSII
   identifier "10" on and set the ILET to UTF-8.

   In the scenario where the client end is not DNSII compliant, either a
   local encoding 8-bit stream or a UTF-8 encoded stream without the
   DNSII flag nor ILET will be transported.  During the transition
   period, should this occur, the above forced UTF-8 conversion and ILET
   insertion would take place and it would be up to the authoritative
   server to determine the existence of the requested domain.  InZone
   DNSII handling mechanism will serve to take care of these
   transitional exceptions.


4. DNSII Conformance Levels

   DNSII is designed for a smooth transition from the existing ASCII
   based DNS to a multilingual capable DNS.  Therefore, it is not
   necessary for all servers and applications to be switched to
   multilingual capable before starting the deployment.

DNSII-MDNR       Multilingual Domain Name Resolution        August 2000



4.1 Application Conformance Levels

   The BASIC compliancy for applications would be to remove validity
   checks for domain names.  The resolution process will determine a
   non-existing domain name, so there really is no need to prevent a DNS
   packet with multilingual labels to be sent through the wires.

   The INTERMEDIATE compliancy for applications involves the insertion
   of the DNSII identifier as well as the ILET according to the local
   inputting and screen scheme.  If a user is using a JIS format scheme,
   it should set the ILET to reflect it being used.  At the same time,
   the tunneling mechanism discussed in Section 3.2 MUST also be in
   place.

   FULLY compliant applications will send all DNS packets with the DNSII
   identifier and the ILET set to UCS-2/4. The fallback scheme discussed
   in Section 3.2 MUST also be in place.  InZone DNSII mechanisms SHOULD
   also be available to deal with local encoding exceptions.


4.2 Resolver Conformance Levels

   The BASIC compliancy for resolvers would be to allow an 8-bit clean
   approach to name resolution.  Also, it should be made sure that the
   additional DNSII RR (TXT) will not be truncated during resolution.

   The INTERMEDIATE compliant resolvers MUST understand how to process
   the DNSII identifier as well as not reject the ILET.  Interpretation
   of the name is not required so it is NOT necessary for the resolvers
   to be able to map all or any of the ILET values (with the alternative
   approach in DNSII-MDNP, the ILET value corresponds to the byte length
   of the characters contained in the label, which makes the count
   workable even if the ILET value is not known by the resolver).  In
   this scenario caching will be for exact comparison only (label to
   label with ILET intact).  The important criteria is for the resolver
   to be able to pass along the DNS query to the corresponding
   authoritative server and obtain a correct response.

   FULLY compliant resolvers will be able to process the DNSII identifer
   and know all the ILET values for full function name mapping.  Cache
   name lookup will be fully enabled and inquiry fallback mechanism
   discussed in Section 3.2.2 SHOULD be performed in the event of
   encountering a non-compliant server.


4.3 Authoritative Server Conformance Levels

   Authoritative servers MUST be fully compliant before attempting to
   serve multilingual sub-domains under its authoritative zone.  They
   should however prepare for the transition towards a multilingual name
   space even if they do not intend to deploy it right away.

DNSII-MDNR       Multilingual Domain Name Resolution        August 2000


   The BASIC compliancy for authoritative name servers is to allow an 8-
   bit clean approach towards sub-domains that are not directly under
   its authority (i.e. sub-sub-domains).

   The INTERMEDIATE compliant name server will be able to process the
   DNSII identifier and ILET without rejecting the query.  The
   authoritative zone as well as its direct sub-domains however SHOULD
   not include the use of the DNSII flags because ILET values are not
   understood at this compliancy level.

   FULLY compliant name servers will be able to handle DNSII compliant
   label formats at its sub-domain levels.  That is, fully compliant
   root servers will be able to serve multilingual TLDs, fully compliant
   TLD servers will be able to serve multilingual SLDs, etc.


5. Transition Schedule & Strategy

   DNSII is designed to allow a gradual adoption of multilingual domain
   names on the Internet.  The transition strategy is therefore geared
   to be demand-pull instead of a technology-push incentive.  However,
   to provide a platform for a demand-pull approach, it is required for
   operators to first safeguard their system.  The simple approach as
   laid out in Section 4 is to propose that servers take a 8-bit clean
   approach on name resolution.

   As discussed in DNSII-MDNP, it is reasonable for the deployment of
   DNSII-MDNP at the registry level first to draw demand for the service
   and let the host level DNSs with multilingual names to begin
   migration first.  DNS operators around the world should however
   prepare for the transition and begin the deployment of DNSII
   depending on their interest in serving multilingual domain names,
   according to the conformance levels laid out in Section 4, beginning
   from BASIC compliancy for operators that are least interested to a
   FULLY compliant server for operators who wishes to provide
   multilingual capabilities for their users.

   The root servers could easily be adjusted to be a BASIC compliant
   authoritative name server.  Once the demand is proven and the
   stability of the system tested, they too could transition to fully
   compliant authoritative servers so that multilingual TLDs could be
   rolled out.


6. Summary of Discussion

   This document introduces the contemplated transition and steady state
   resolution process for multilingual domain names with a DNSII
   compliant format.  Two tunneling mechanisms using the TXT RR was
   introduced for the preservation of information during transitional
   resolution.


DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

6.1 Client/Application Resolution Strategy

   Send Query in DNSII format
   IF RCODE = Format Error
        THEN send query in UTF-8/Local Encoding AND append DNSII RR
        IF RCODE = Format Error
             THEN send Query in ASCII with _-for-tunneling-only-_ label
             AND append DNSII RR
             AND check for DNSII ANS RR in response
        ELSE proceed and check for DNSII ANS RR in response
   ELSE proceed as usual


6.2 Resolver Resolution Strategy

   (*)IF incoming request is in pure DNSII format
        THEN resolve according to ILET in cache and by recursive lookup
        IF encounter RCODE = Format Error
             THEN send query in UTF-8 AND append DNSII RR
             IF RCODE = Format Error
                  THEN send query in ASCII with _-for-tunneling-only-_
                       label
                  AND append DNSII RR
                  AND check for DNSII ANS RR in response
             ELSE proceed and check for DNSII ANS RR in response
        ELSE proceed as usual with pure DNSII Format (*)
        AND respond in pure DNSII format
   ELSE IF incoming request has tunneled MDNP information
        THEN resolve using the information in the appended DNSII RR
             Reset Query using DNSII Format and go through (*)
        AND convert back to tunneling format before responding to query
             With DNSII ANS RR appended to response
        AND set TTL for regular RRs in the Answer field to be = 0
   ElSE IF incoming request is in the original "00" label format
        AND no tunneled information is included
        AND the label contains characters beyond A-z, 0-9 or "-"
        THEN force convert all labels to UTF-8
        AND query using DNSII Format and go through (*)
   ELSE proceed as usual (existing ASCII based names)


6.3 Authoritative Name Server Resolution Strategy

   IF incoming request is in pure DNSII format
        THEN resolve according to ILET
        AND respond in pure DNSII format
   ELSE IF incoming request has tunneled MDNP information
        THEN resolve using the information in the appended DNSII RR
        AND convert back to tunneling format before responding to query
             With DNSII ANS RR appended to response
        AND set TTL for regular RRs in the Answer field to be = 0
   ELSE use InZone DNSII mechanisms AND use 8-bit clean approach


DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

7. Security Considerations

   DNSII RRs will be secured through transaction authentication, while
   DNSII ANS RRs could have their own SIG RRs.  In general, the DNSII-
   MDNR should not constitute any extra burden on DNS security.


8. Intellectual Property Considerations

   It is the intention of Neteka to submit the DNSII protocol and other
   elements of the multilingual domain name server software to IETF for
   review, comment or standardization.

   Neteka Inc. has applied for one or more patents on the technology
   related to multilingual domain name server software and multilingual
   email server software suite.  If a standard is adopted by IETF and
   any patents are issued to Neteka with claims that are necessary for
   practicing the standard, any party will be able to obtain the right
   to implement, use and distribute the technology or works when
   implementing, using or distributing technology based upon the
   specific specifications under fair, reasonable and non-discriminatory
   terms.

   Other DNSII related documents and discussions could be found at
   http://www.dnsii.org.

9. References

   [DNSII-MDNP] E. Chung & D. Leung "DNSII Multilingual Domain Name
              Protocol", August 2000

   [RFC1700]   J. Reynolds, J. Postel, "ASSIGNED NUMBERS", RFC
              1700, October 1994.

   [ISO10646] ISO/IEC 10646-1:2000. International Standard --
              Information technology -- Universal Multiple-Octet Coded
              Character Set (UCS)

   [RFC1034]  Mockapetris, P., "Domain Names - Concepts and
              Facilities," STD 13, RFC 1034, USC/ISI, November 1987

   [RFC1035]  Mockapetris, P., "Domain Names - Implementation and
              Specification," STD 13, RFC 1035, USC/ISI, November
              1987

   [RFC2119]  S. Bradner, "Key words for use in RFCs to Indicate
              Requirement Levels," RFC 2119, March 1997







DNSII-MDNR       Multilingual Domain Name Resolution        August 2000

   Authors:

   Edmon Chung
   Neteka Inc.
   2462 Yonge St. Toronto,
   Ontario, Canada M4P 2H5
   edmon@neteka.com

   David Leung
   Neteka Inc.
   2462 Yonge St. Toronto,
   Ontario, Canada M4P 2H5
   david@neteka.com