ENUM                                                        P. Faltstrom
Internet-Draft                                         Cisco Systems Inc
Expires: November 30, 2002                                   M. Mealling
                                                                VeriSign
                                                               June 2002


                   The E.164 to URI DDDS Application
                   draft-ietf-enum-rfc2916bis-01.txt

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.

   This Internet-Draft will expire on November 30, 2002.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document discusses the use of the Domain Name System (DNS) for
   storage of E.164 numbers.  More specifically, how DNS can be used for
   identifying available services connected to one E.164 number.  It
   specifically obsoletes RFC 2916 to bring it in line with the Dynamic
   Delegation Discovery System (DDDS) Application specification found in
   the document series specified in RFC WWWW.  It is very important to
   note that it is impossible to read and understand this document
   without reading the documents discussed in RFC WWWW.





Faltstrom & Mealling    Expires November 30, 2002               [Page 1]


Internet-Draft                    ENUM                         June 2002


Table of Contents

   1.      Introduction . . . . . . . . . . . . . . . . . . . . . . .  3
   1.1     Terminology  . . . . . . . . . . . . . . . . . . . . . . .  3
   1.2     Use for these mechanisms for private dialing plans . . . .  3
   1.3     Application of local policy  . . . . . . . . . . . . . . .  3
   2.      The ENUM Application Specifications  . . . . . . . . . . .  4
   2.1     Application Unique String  . . . . . . . . . . . . . . . .  4
   2.2     First Well Known Rule  . . . . . . . . . . . . . . . . . .  4
   2.3     Expected Output  . . . . . . . . . . . . . . . . . . . . .  4
   2.4     Valid Databases  . . . . . . . . . . . . . . . . . . . . .  4
   2.4.1   Flags  . . . . . . . . . . . . . . . . . . . . . . . . . .  5
   2.4.2   Services Parameters  . . . . . . . . . . . . . . . . . . .  6
   2.4.2.1 ENUM Services  . . . . . . . . . . . . . . . . . . . . . .  6
   3.      Registration mechanism for Enumservices  . . . . . . . . .  8
   3.1     Registration Requirements  . . . . . . . . . . . . . . . .  8
   3.1.1   Functionality Requirement  . . . . . . . . . . . . . . . .  8
   3.1.2   Naming requirement . . . . . . . . . . . . . . . . . . . .  8
   3.1.3   Security requirement . . . . . . . . . . . . . . . . . . .  8
   3.1.4   Publication Requirements . . . . . . . . . . . . . . . . .  9
   3.2     Registration procedure . . . . . . . . . . . . . . . . . .  9
   3.2.1   IANA Registration  . . . . . . . . . . . . . . . . . . . .  9
   3.2.1.1 Location of ENUM Enumservice Registrations . . . . . . . .  9
   3.2.1.2 Change Control . . . . . . . . . . . . . . . . . . . . . . 10
   3.2.2   Registration Template  . . . . . . . . . . . . . . . . . . 10
   4.      Examples . . . . . . . . . . . . . . . . . . . . . . . . . 11
   4.1     Example 1  . . . . . . . . . . . . . . . . . . . . . . . . 11
   4.2     Example 2  . . . . . . . . . . . . . . . . . . . . . . . . 11
   4.3     Example 3  . . . . . . . . . . . . . . . . . . . . . . . . 11
   5.      IANA Considerations  . . . . . . . . . . . . . . . . . . . 13
   6.      Security Considerations  . . . . . . . . . . . . . . . . . 14
   7.      Acknowledgments  . . . . . . . . . . . . . . . . . . . . . 15
           References . . . . . . . . . . . . . . . . . . . . . . . . 16
           Authors' Addresses . . . . . . . . . . . . . . . . . . . . 16
           Full Copyright Statement . . . . . . . . . . . . . . . . . 18
















Faltstrom & Mealling    Expires November 30, 2002               [Page 2]


Internet-Draft                    ENUM                         June 2002


1. Introduction

   Through transformation of E.164 [9] numbers into DNS names and the
   use of existing DNS services like delegation through NS records and
   NAPTR records, one can look up what services are available for a
   specific domain name in a decentralized way with distributed
   management of the different levels in the lookup process.

   The domain "e164.arpa" is being populated in order to provide the
   infrastructure in DNS for storage of E.164 numbers.  In order to
   facilitate distributed operations, this domain is divided into
   subdomains.  Holders of E.164 numbers which want to be listed in DNS
   should contact the appropriate zone administrator in order to be
   listed, by examining the SOA resource record associated with the
   zone, just like in normal DNS operations.

   Of course, as with other domains, policies for such listings will be
   controlled on a subdomain basis and may differ in different parts of
   the world.

1.1 Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119.

   All capitalized terms are taken from the vocabulary found in the DDDS
   algorithm specification found in RFC ZZZZ [3].

1.2 Use for these mechanisms for private dialing plans

   This document specifies how "ENUM" works, that is how to handle
   numbers allocated according to the ITU-T standard E.164.  But, a
   similar mechanism can be used also for other numbers, such as private
   dialing plans.  To implement that (a) a different domain, well-known
   for all parties using the same dialing plan, SHOULD be selected and
   (b) the application unique string (see section 3.1 below) SHOULD be
   the full number as specified but without the leading '+'.

1.3 Application of local policy

   The priority field in the NAPTR is a request from the holder of the
   E.164 in what order the records are to be used.  It is to be noted
   that the party looking up the records MAY apply a local policy for in
   what order the records are to be used based on a combination of the
   service fields and URI schemes.





Faltstrom & Mealling    Expires November 30, 2002               [Page 3]


Internet-Draft                    ENUM                         June 2002


2. The ENUM Application Specifications

   This template defines the ENUM DDDS Application according to the
   rules and requirements found in [3].  The DDDS database used by this
   Application is found in [4] which is the document that defines the
   NAPTR DNS Resource Record type.

2.1 Application Unique String

   The Application Unique String is a fully qualified E.164 number minus
   any non-digit characters except for the '+' character which appears
   at the beginning of the number.  The "+" is kept to provide a well
   understood anchor for the AUS in order to distinguish it from other
   telephone numbers that are not part of the E.164 namespace.

   For example, the E.164 number could start out as "+1-770-923-9595".
   To ensure that no syntactic sugar is allowed into the AUS, all non-
   digits except for "+" are removed, yielding "+17709239595".

2.2 First Well Known Rule

   The First Well Known Rule for this Application is the identity rule.
   The output of this rule is the same as the input.  This is because
   the E.164 namespace and this Applications databases are organized in
   such a way that it is possible to go directly from the name to the
   smallest granularity of the namespace directly from the name itself.

   Take the previous example, the AUS is "+17709239595".  Applying the
   First Well Known Rule produces the exact same string, "+17709239595".

2.3 Expected Output

   The output of the last DDDS loop is a Uniform Resource Identifier in
   its absolute form according to the 'absoluteURI' production in the
   Collected ABNF found in RFC2396 [7].

2.4 Valid Databases

   At present only one DDDS Database is specified for this Application.
   "Dynamic Delegation Discovery System (DDDS) Part Three:  The DNS
   Database" (RFC ZZZZ) [4] specifies a DDDS Database that uses the
   NAPTR DNS resource record to contain the rewrite rules.  The Keys for
   this database are encoded as domain-names.

   The output of the First Well Known Rule for the ENUM Application is
   the E.164 number minus all non-digit characters except for the +.  In
   order to convert this to a unique key in this Database the string is
   converted into a domain-name according to this algorithm:



Faltstrom & Mealling    Expires November 30, 2002               [Page 4]


Internet-Draft                    ENUM                         June 2002


   1.  Remove all characters with the exception of the digits.  For
       example, the First Well Known Rule produced the Key
       "+4689761234".  This step would simply remove the leading "+",
       producing "4689761234".

   2.  Put dots (".") between each digit.  Example: 4.6.8.9.7.6.1.2.3.4

   3.  Reverse the order of the digits.  Example: 4.3.2.1.6.7.9.8.6.4

   4.  Append the string ".e164.arpa" to the end.  Example:
       4.3.2.1.6.7.9.8.6.4.e164.arpa

   This domain-name is used to request NAPTR records which may contain
   the end result or, if the flags field is blank, produces new keys in
   the form of domain-names from the DNS.

   DNS servers MAY interpret Flag values and use that information to
   include appropriate resource records in the Additional Information
   portion of the DNS packet.  Clients are encouraged to check for
   additional information but are not required to do so.  See the
   Additional Information Processing section of RFC YYYY for more
   information on NAPTR records and the Additional Information section
   of a DNS response packet.

   The character set used to encode the substitution expression is UTF-
   8.  The allowed input characters are all those characters that are
   allowed anywhere in an E.164 number.  The characters allowed to be in
   a Key are those that are currently defined for DNS domain-names.

2.4.1 Flags

   This Database contains a field that contains flags that signal when
   the DDDS algorithm has finished.  At this time only one flag, "U", is
   defined.  This means that this Rule is the last one and that the
   output of the Rule is a URI [7].

   If a client encounters a record with an unknown flag, it MUST ignore
   it and move to the next Rule.  This test takes precedence over any
   ordering since flags can control the interpretation placed on fields.
   A novel flag might change the interpretation of the regexp and/or
   replacement fields such that it is impossible to determine if a
   record matched a given target.

   If this flag is not present then this rule is non-terminal.  If a
   Rule is non-terminal then clients MUST use the Key produced by this
   Rewrite Rule as the new Key in the DDDS loop (i.e.  causing the
   client to query for new NAPTR records at the domain-name that is the
   result of this Rule).



Faltstrom & Mealling    Expires November 30, 2002               [Page 5]


Internet-Draft                    ENUM                         June 2002


2.4.2 Services Parameters

   Service Parameters for this Application take the following form and
   are found in the Service field of the NAPTR record.


                    service_field = "E2U" 1*(enumservice)
                 enumservice   = service [":" protocol]
                    service       = 1*32(ALPHA / DIGIT)
                    protocol      = 1*32(ALPHA / DIGIT)


   In other words, a non-optional "E2U" (used to denote ENUM only
   Rewrite Rules in order to mitigate record collisions) followed by 1
   or more or more Enumservices which indicate what class of
   functionality a given end point offers.  Each Enumservice is
   indicated by an initial '+' character.

   The empty string is also valid.  This will typically be seen at the
   beginning of a series of Rules, when it is impossible to know what
   services and protocols will be offered at the end of a particular
   delegation path.

2.4.2.1 ENUM Services

   An enumservice MUST be registered with the IANA via a description in
   an RFC.  Enumservices specifications contain the functional
   specification (i.e.  what it can be used for), the valid protocols,
   and the URI schemes that may be returned.  Note that there is no
   implicit mapping between the textual string "protocol" and "service"
   in the grammar for the Enumserver and URI schemes.  The mapping have
   to be made explicit in the specification for the Enumservice itself.
   It is allowed to specify the service and protocol in two different
   documents, to make the description coherent and easy to understand.
   For example, the Enumservice "presence" (note, no protocol
   specification) would define the various URI schemes ("im:",
   "mailto:") can be used and what the service can be used for ("Where
   is the owner of this E.164 number?").  Another example might be
   "talk:sip" which can specify that the URI must use the 'sip:' URI
   scheme and use the SIP protocol to make a voice call (as opposed to a
   voice mail call or fax call).  What final protocol to use for the
   actual transport of voice is negotiated in the SIP protocol
   negotiation.

   The only exception to the registration rule is for services and
   protocols used for experimental purposes, and those are to start with
   the facet "X-".  These types are unregistered, experimental, and
   should be used only with the active agreement of the parties



Faltstrom & Mealling    Expires November 30, 2002               [Page 6]


Internet-Draft                    ENUM                         June 2002


   exchanging them.

   The registration mechanism is specified in Section 3.
















































Faltstrom & Mealling    Expires November 30, 2002               [Page 7]


Internet-Draft                    ENUM                         June 2002


3. Registration mechanism for Enumservices

   Registration of Enumservices requires approval by the IESG and
   publication of the Enumservice registration as some form of RFC.

3.1 Registration Requirements

   Service registration proposals are all expected to conform to various
   requirements laid out in the following sections.

3.1.1 Functionality Requirement

   An Enumservice registered must be able to function as a selection
   mechanism when choosing one NAPTR resource record from another.  That
   means that the registration MUST specify what is expected when using
   that very NAPTR record, and the URI which is the outcome of the use
   of it.

   Specifically, a registered Enumservice MUST specify the URI scheme(s)
   that may be used for the Enumservice, and, when needed, other
   information which will have to be transfered into the URI resolution
   process itself (LDAP DNs, transferring of the AUS into the resulting
   URI, etc).

3.1.2 Naming requirement

   The name of an Enumservice MUST be unique, conform to the ABNF
   specified in Section 2.4.2, and MUST NOT start with the facet "X-"
   which is reserved for experimental, private use.

3.1.3 Security requirement

   An analysis of security issues is required for for all Enumservices
   registered.  (This is in accordance with the basic requirements for
   all IETF protocols.)

   All descriptions of security issues must be as accurate as possible
   regardless of registration tree.  In particular, a statement that
   there are "no security issues associated with this Enumservice" must
   not be confused with "the security issues associates with this
   Enumservice have not been assessed".

   There is absolutely no requirement that Enumservices registered must
   be secure or completely free from risks.  Nevertheless, all known
   security risks must be identified in the registration of a
   Enumservice.

   The security considerations section of all registrations is subject



Faltstrom & Mealling    Expires November 30, 2002               [Page 8]


Internet-Draft                    ENUM                         June 2002


   to continuing evaluation and modification.

   Some of the issues that should be looked at in a security analysis of
   a Enumservice are:

   1.  Complex Enumservices may include provisions for directives that
       institute actions on a users resources.  In many cases provision
       can be made to specify arbitrary actions in an unrestricted
       fashion which may then have devastating results.  Especially if
       there is a risk for a new ENUM lookup, and because of that an
       infinite loop in the overall resolution process of the E.164.

   2.  Complex Enumservices may include provisions for directives that
       institute actions which, while not directly harmful, may result
       in disclosure of information that either facilitates a subsequent
       attack or else violates the users privacy in some way.

   3.  An Enumservice might be targeted for applications that require
       some sort of security assurance but not provide the necessary
       security mechanisms themselves.  For example, a Enumservice could
       be defined for storage of confidential medical information which
       in turn requires an external confidentiality service.


3.1.4 Publication Requirements

   Proposals for Enumservices registered must be published as RFCs.
   IANA will retain copies of all Enumservice registration proposals and
   "publish" them as part of the ENUM Enumservice Registration tree
   itself.

3.2 Registration procedure

   Normal IETF processes should be used for publication of the RFC which
   is the basis of the registration of the Enumservice itself.

3.2.1 IANA Registration

   Provided that the Enumservice has obtained approval that is
   necessary, and the RFC is published, IANA will register the
   Enumservice and make the Enumservice registration available to the
   community in addition to the RFC publication itself.

3.2.1.1 Location of ENUM Enumservice Registrations

   Enumservice registrations will be published in the IANA repository
   and made available via anonymous FTP at the following URI: "ftp://
   ftp.isi.edu/in-notes/iana/assignments/enum-services/".



Faltstrom & Mealling    Expires November 30, 2002               [Page 9]


Internet-Draft                    ENUM                         June 2002


3.2.1.2 Change Control

   Change control of Enumservices stay with the IETF via the RFC
   publication process.  Especially, Enumservice registrations may not
   be deleted; Enumservices which are no longer believed appropriate for
   use can be declared OBSOLETE by publication of a new RFC and a change
   to their "intended use" field; such media types will be clearly
   marked in the lists published by IANA.

3.2.2 Registration Template

   Enumservice Name:

   URI Scheme(s):

   Functional Specification:

   Security considerations:

   Intended usage: (One of COMMON, LIMITED USE or OBSOLETE)

   Author:

   Any other information that the author deems interesting:



























Faltstrom & Mealling    Expires November 30, 2002              [Page 10]


Internet-Draft                    ENUM                         June 2002


4. Examples

   The examples below use theoretical services which uses Enumservices
   which might not make sense, but they are still used for educational
   purposes.  For example, the protocol used is exactly the same as the
   URI scheme.  That was the specification in RFC 2916, but this default
   specification of a Enumservice is no longer allowed.  All
   Enumservices need to be registered explicitly by the procedure
   specified in section Section 3N.

4.1 Example 1



   $ORIGIN 4.3.2.1.6.7.9.8.6.4.e164.arpa.
      IN NAPTR 100 10 "u" "E2U+talk:sip"       "!^.*$!sip:info@tele2.se!"     .
      IN NAPTR 102 10 "u" "E2U+message:mailto" "!^.*$!mailto:info@tele2.se!"  .


   This describes that the domain 4.3.2.1.6.7.9.8.6.4.e164.arpa is
   preferably contacted by SIP for voice, and secondly by SMTP for
   messaging.

   In both cases, the next step in the resolution process is to use the
   resolution mechanism for each of the protocols, (specified by the URI
   schemes SIP and SMTP) to know what node to contact for each.

4.2 Example 2



   $ORIGIN 4.3.2.1.6.7.9.8.6.4.e164.arpa.
     IN NAPTR  10 10 "u" "E2U+talk:sip+message:sip" "!^.*$!sip:paf@swip.net!"    .
     IN NAPTR 102 10 "u" "E2U+message:mailto"       "!^.*$!mailto:paf@swip.net!" .
     IN NAPTR 102 10 "u" "E2U+talk:tel"             "!^(.*$)$!tel:\1!"           .


   Note that one can use the sip protocol for both "talk" and "message",
   and that the sip URI is the preferred URI to use.  The URI is
   resolved as described in RFC 2543 [6].  In the case of the "tel" URI
   scheme [7], a replacement "\1" is used.

   The rest of the resolution of the routing is done as described above.

4.3 Example 3






Faltstrom & Mealling    Expires November 30, 2002              [Page 11]


Internet-Draft                    ENUM                         June 2002


      $ORIGIN 6.4.e164.arpa.
      * IN NAPTR 100 10 "u" "E2U+vpim:ldap" "!^+46(.*)$!ldap://ldap.se/cn=\1!" .


   We see in this example that information about all E.164 numbers in
   the 46 countrycode (for Sweden) exists in an LDAP server, and the
   search to do is specified by the LDAP URI [8].  The service vpim is
   used to mention that the database explicitly holds data according to
   some (hypothetical) vpim (Voice Profile for Internet Mail)
   specification.









































Faltstrom & Mealling    Expires November 30, 2002              [Page 12]


Internet-Draft                    ENUM                         June 2002


5. IANA Considerations

   This memo requests that the IANA delegate the E164.ARPA domain
   following instructions to be provided by the IAB.  Names within this
   zone are to be delegated to parties according to the ITU
   recommendation E.164.  The names allocated should be hierarchic in
   accordance with ITU Recommendation E.164, and the codes should
   assigned in accordance with that Recommendation.

   IAB is to coordinate with ITU-T TSB if the technical contact for the
   domain e164.arpa is to change, as ITU-T TSB has an operational
   working relationship with this technical contact which needs to be
   reestablished.

   Delegations in the zone e164.arpa (not delegations in delegated
   domains of e164.arpa) should be done after Expert Review, and the
   IESG will appoint a designated expert.

   IANA is to create a registry for ENUM Enumservices as specified in
   Section 3.  Whenever a new ENUM Enumservice is registered by the RFC
   process in the IETF, IANA is at the time of publication of the RFC to
   register the Enumservice and add a pointer to the RFC itself.





























Faltstrom & Mealling    Expires November 30, 2002              [Page 13]


Internet-Draft                    ENUM                         June 2002


6. Security Considerations

   As this system is built on top of DNS, one can not be sure that the
   information one get back from DNS is more secure than any DNS query.
   To solve that, the use of DNSSEC [9] for securing and verifying zones
   is to be recommended.

   The caching in DNS can make the propagation time for a change take
   the same amount of time as the time to live for the NAPTR records in
   the zone that is changed.  The use of this in an environment where
   IP-addresses are for hire (for example, when using DHCP [11]) must
   therefore be done very carefully.

   There are a number of countries (and other numbering environments) in
   which there are multiple providers of call routing and number/name-
   translation services.  In these areas, any system that permits users,
   or putative agents for users, to change routing or supplier
   information may provide incentives for changes that are actually
   unauthorized (and, in some cases, for denial of legitimate change
   requests).  Such environments should be designed with adequate
   mechanisms for identification and authentication of those requesting
   changes and for authorization of those changes.

   A large amount of Security Issues have to do with the resolution
   process itself, and use of the URIs produced by the DDDS mechanism.
   Those have to be specified in the registration of the ENUM
   Enumservice used, as specified in Section 3.1.3.
























Faltstrom & Mealling    Expires November 30, 2002              [Page 14]


Internet-Draft                    ENUM                         June 2002


7. Acknowledgments

   Support and ideas leading to RFC 2916 have come from people at
   Ericsson, Bjorn Larsson and the group which implemented this scheme
   in their lab to see that it worked.  Input has also arrived from ITU-
   T SG2, Working Party 1/2 (Numbering, Routing, Global Mobility and
   Enumservice Definition), the ENUM working group in the IETF, John
   Klensin and Leif Sunnegardh.

   This update of RFC 2916 is created with specific input from: Randy
   Bush, David Conrad, Richard Hill, Jim Reid, Joakim Stralmark, Robert
   Walter and James Yu.







































Faltstrom & Mealling    Expires November 30, 2002              [Page 15]


Internet-Draft                    ENUM                         June 2002


References

   [1]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
        One: The Comprehensive DDDS Standard", RFC WWWW, draft-ietf-urn-
        ddds-toc-02.txt (work in progress), February 2002.

   [2]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
        Two: The Algorithm", RFC XXXX, draft-ietf-urn-ddds-06.txt (work
        in progress), February 2002.

   [3]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
        Three: The DNS Database", RFC ZZZZ, draft-ietf-urn-dns-ddds-
        database-08.txt (work in progress), February 2002.

   [4]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
        Four: The URI Resolution Application", RFC YYYY, draft-ietf-urn-
        uri-res-ddds-06.txt (work in progress), February 2002.

   [5]  Mealling, M., "Dynamic Delegation Discovery System (DDDS) Part
        Five: URI.ARPA Assignment Procedures", RFC VVVV, draft-ietf-urn-
        net-procedures-10.txt (work in progress), February 2002.

   [6]  Mealling, M., "URI Resolution Services Necessary for URN
        Resolution", RFC 2483, January 1999.

   [7]  Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource
        Identifiers (URI): Generic Syntax", RFC 2396, August 1998.

   [8]  Petke, R. and I. King, "Registration Procedures for URL Scheme
        Names", RFC 2717, BCP 35, November 1999.

   [9]  ITU-T, "The International Public Telecommunication Number Plan",
        Recommendation E.164, May 1997.


Authors' Addresses

   Patrik Faltstrom
   Cisco Systems Inc
   170 W Tasman Drive SJ-13/2
   San Jose, CA  95134
   USA

   EMail: paf@cisco.com
   URI:   http://www.cisco.com






Faltstrom & Mealling    Expires November 30, 2002              [Page 16]


Internet-Draft                    ENUM                         June 2002


   Michael Mealling
   VeriSign
   21345 Ridgetop Circle
   Sterling, VA  20166
   US

   EMail: michael@neonym.net
   URI:   http://www.verisignlabs.com











































Faltstrom & Mealling    Expires November 30, 2002              [Page 17]


Internet-Draft                    ENUM                         June 2002


Full Copyright Statement

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















Faltstrom & Mealling    Expires November 30, 2002              [Page 18]