ENUM Overview

1
ENUM Overview

• Steven D. Lind
• CC1 ENUM LLC PETPAC
• June 13, 2006

2
What is ENUM?

• Provides mapping from E.164 numbers to IP
  resources
• Telephone number as domain name
• Built on top of DNS
• Number assignees must opt in
• Example 1-973-236-6797

Lookup 7.9.7.6.6.3.2.3.7.9.1.e164.arpa
DNS
sipsfisher_at_att.net sip sfisher_at_verizon.com ma
iltosfisher1_at_att.com mailtosteve_fisher_at_yahoo.c
om
3
Why is ENUM important?

• A public ENUM will enable VoIP interoperability
• E.164 addresses will be used in VoIP networks
• Interoperability with the PSTN
• Prevalence of devices with 12 digit keypads
• ENUM enables call routing between VoIP service
  providers
• E.164 addresses are not routable in an IP/VoIP
  network
• Use ENUM to map E.164 number to an Internet
  address that can be used to setup communication
  (e.g. sip19732366797_at_xyz.net)

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Three Pieces to the ENUM Puzzle
ENUMEnabledApplications
DomainNameSystem
Provisioning
Authentication ValidationEntities
Tier 0
Registrar
Registry
Tier 1

• voice
• fax
• messaging presence
• email
• web pages

ApplicationServiceProvider
Tier 2
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End-user vs. Provider ENUM

• End-user ENUM
• Requires end-user opt-in
• NAPTR records designate communication end-points
  for various applications
• Provider ENUM
• NAPTR records designate points of interconnection
  between peering partners
• Service providers input all allocated numbers

6
The Public ENUM Infrastructure
e164.arpa
Tier 0 (Country Code Registry)
ORIGIN e164.arpa. 3.7.9.1 IN NS
nsnanp.enum.com . 4.4 IN NS sweden_enum.com .

Tier 1 (Telephone Number Registry)
ORIGIN 3.7.9.1.e164.arpa. 7.9.7.6.6.3.2 IN NS
e164.att.net . 8.9.7.6.6.3.2 IN NS e164.xyz.com
.
Tier 2 (Application Information)
ORIGIN 7.9.7.6.6.3.2.3.7.9.1.e164.arpa. IN
NAPTR 100 10 "u" E2Usip" "!.!sip19732366797_at_
att.net!" .
International Implementation worked in IETF and
ITU-T
National Implementation worked in ENUM Forum (US)
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Provider ENUM Trial Infrastructure
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IETF ENUM WG

• Developed RFC 3761 which described ENUM
  protocol using e164.arpa domain
• Currently working on Infrastructure ENUM
• Requirements I-D through WG last
  callhttp//www.ietf.org/internet-drafts/draft-iet
  f-enum-infrastructure-enum-reqs-02.txt
• Implementation I-D has first draft
  postedhttp//www.ietf.org/internet-drafts/draft-i
  etf-enum-infrastructure-00.txt

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ITU-T/IAB/RIPE-NCC

• Operating Tier 0 Registry for E.164 country code
  delegations
• Interim procedures govern delegation procedures
• http//www.itu.int/ITU-T/inr/enum/procedures.html
• http//www.itu.int/ITU-T/inr/enum/procedures-02.ht
  ml
• 35 countries, shared network code for Antarctic
  research organizations, and UPT numbering space
  for VisionNG (http//www.itu.int/itudoc/itu-t/enum
  /enum-app.pdf)

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ENUM Forum

• Loose organization of mostly US telecomm and
  Internet industry members
• Developed high level requirements for US ENUM
  implementation
• 6000_1_0 ENUM Forum Specifications for US
  Implementation of ENUM Document
• 6001_1_0 US ENUM Implementation-Tier 1
  Contracting Entity and Architectural Alternatives
  
• 6002_1_0 ENUM Implementation for Toll free
  Non-Geographic Codes
• 6003_1_0 Framework Document for a US/CC1 ENUM
  Trials Program

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CC1 ENUM LLC

• Responsible for implementation of DNS
  infrastructure for NANP-wide Tier 1A Registry and
  US Tier 1B through RFPs
• First draft of Tier 1A RFP sent to CC1 government
  agencies for comment
• First Draft of Tier 1B RFP almost complete
• Sponsoring End-user and Provider ENUM Trials