Internet Engineering Task Force              William Dutcher
Internet-Draft                                Verisign, Inc.
February 20, 2002
                                           Kevin  McCandless
                                             Illuminet, Inc.

                                    Expires: August 20, 2002
Category: Informational


                       ENUM Root Domain
                <draft-dutcher-enum-root-domain-01.txt>

. Status of this Memo

This  document  is  an Internet-Draft and is in full confor-
mance with all provisions of Section 10 of RFC2026.

Internet-Drafts are working documents of the Internet  Engi-
neering  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/lid-abstracts.html.

The  list  of  Internet-Draft  Shadow  Directories  can   be
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. Abstract

RFC  2916  specifies  that  the domain e164.arpa is the root
domain for the DNS storage  for  NAPTR  records  for  ENUMs.
This  document  proposes  that the root domain referenced in
RFC 2916 be changed from e164.arpa to a generic domain, such
as  e164.foo.   This  would give developers of ENUM applica-
tions a greater degree of  flexibility  in  configuring  DNS
structures for ENUM.  ENUM will still have only one root.


. Discussion

RFC  2916 specifies that the domain e164.arpa be used as the
root domain for the DNS storage hierarchy for NAPTR  records
for ENUMs.  However, several contributions have been made to
the ITU-T Study Group 2 proposing alternative roots, as well
as alternative DNS hierarchies.

This  document  proposes  that the root domain referenced in
RFC 2916 be changed from  e164.arpa  to  a  generic  domain.









                             -2-


This  would  allow  the  developers of ENUM applications, as
well as the providers of DNS  infrastructures  that  support
ENUM,  a  greater  degree  of flexibility in configuring DNS
structures that will be used by ENUM.  This change will also
allow the RFC to guide the technical specifications of ENUM,
rather than describe policy.

It should be clear that this proposal is not suggesting that
RFC  2916  be  updated to allow for multiple values for that
generic domain. In adherence to the goal of RFC 2916,  there
still  should  be one and only one domain at the root of the
ENUM system.  This document is simply suggesting that in any
update  to  RFC  2916  that  the value 'e164.arpa' be easily
changeable to another value; especially in light of  ongoing
discussions between the IAB and the ITU. The relative merits
of how that generic value is designated are discussed below.

According  to  RFC  2916,  the only DNS domain in which ENUM
NAPTR records should be stored is the e164.arpa domain.  The
RFC  is specific in this regard, as indicated in the Section
 of the RFC:

"2. E.164 Numbers and DNS

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 zone, just like in  nor-
mal DNS operations."

In  specifying  the use of the e164.arpa domain for ENUM DNS
records, the RFC may force designers  of  ENUM  applications
and  systems into using a DNS root domain that does not meet
the operational requirements of an  ENUM  application.   For
example, it may be more practical for an ENUM application to
be in a different root-level domain.  Several  contributions
to  the ENUM Forum and to ITU-T Study Group 2 have suggested
various tiered architectures, each  of  which  may  be  more
efficient and more practical if they are not tied by the RFC
to the e164.arpa domain.

Since RFC 2916 specifies .arpa as the TLD, it has created  a
policy  decision  rather  than  a  technical decision.  As a
result, policy agencies are struggling with the .arpra issue
instead  of deciding whether or not global ENUM is an appro-
priate approach.  If this policy recommendation  is  removed
from  RFC  2916,  these agencies will be able to address the
TLD for ENUM without the burden of the TLD  decision  having
been presupposed.

Furthermore,  the  U.S. government supports a domain-neutral









                             -3-


approach to ENUM implementation. Removing the  reference  to
the  e164.arpa  domain  for  ENUM  DNS systems will create a
domain-neutral position in the RFC,  and  remove  a  mandate
that  may inhibit the flexibility of the design and develop-
ment of ENUM systems.


. Recommendation

The recommendation is that the references to  the  e164.arpa
domain  in RFC 2916 be changed to refer to a generic domain,
such as e164.foo.  Further more, when  policy  agencies  and
industry  reach  a  decision  on  the root for ENUM, then an
informational draft can be published documenting the  agree-
ments.


. IANA Considerations

There are no IANA issues to consider in this draft.  This is
an informational draft.


.  Security Considerations

There are no security considerations in this draft.  This is
an informational draft.


. References

RFC  2915   M.  Mealling and R. Daniel, The Naming Authority
Pointer (NAPTR) DNS Resource Record, September 2000.

RFC 2916  P.Faltstrom, E.164 number and DNS, September 2000.


. Authors Addresses

William Dutcher
VeriSign, Inc.
 Ridgetop Circle
Sterling, VA 20166 United States
Phone: +1-703-948-4457
Fax: +1-703-948-4457
Email: bdutcher@verisign.com

Kevin McCandless
Illuminet, Inc.
 West 129th Street
Overland Park, KS 66213 United States
Phone: +1-913-814-6397
Fax: +1-913-814-6505
Email: kmccandless@illuminet.com

A.  Full Copyright Statement







                             -4-


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