ENUM in the U.S.
Ken Hansen & James Yu
NeuStar, Inc.
February 24, 2003
What is ENUM?
ENUM is a scheme that put telephone number into the Domain Name System (DNS) in a single “golden tree” domain so that resources or end point addresses associated with that telephone number can be resolved in the IP domain
Simple ENUM Call Flow SIP
ENUM Global Directory (DNS) Equates +1-202-555-1234 to sip:[email protected] to enable Voice over IP using SIP
1. The caller simply dials the person’s normal telephone number
2. Calling party proxy UAC queries DNS for location of end point
3. DNS returns NAPTR record containing SIP URL to Calling Party UA
4. Calling party UA connects the call
U.S. ENUM Forum Structure
ENUMForum
TaskGroups
SpecialGroups
LeadershipTeam
- Applications- Architecture & Infrastructure- Interoperability- Privacy & Security- Provisioning
- External Communications- Legal Experts
What Has Happened in the U.S. -ENUM Forum
• Specification approved on 2/11
http://www.enum-forum.org/documents/6000_0_9
Letter ballot comments to be resolved
• Issues not addressed in the specification:
– Non-geographic numbers (e.g., toll free numbers)
– Non-US 1+NPA codes
– Registrar accreditation
– Single vs. multiple Tier 1 Registries
• On 2/13/03, ENUM Forum members met with NTIA, FCC and FTC to discuss next steps
• Plan to work on non-geographic numbers next
ENUM Forum Specification Covers
• Reference architecture
• Tier 1 Registry requirements
• ENUM Registrar requirements
• Tier 2 Provider guidelines
• Provisioning scenarios and procedures
• Authentication & authorization
• Privacy considerations
• Dispute resolution
What Has Happened in the U.S. -US Government
• In 9/01 ITU-T SG2 meeting, U.S. expressed its support for ITU-T’s work on RFC2916, which designate e164.arpa
• In 8/02, NTIA held a forum on ENUM benefits and challenges
• In 2/03, NTIA pledged active U.S. government participation in the global ENUM effort
– Internationally - formally opt in to e164.arpa after addressing certain key preliminary issues regarding US implementation of ENUM
– Domestically - ensure that ENUM can be implemented in a pro-consumer, secure and competitive manner
NTIA is to lead the ENUM effort within the US government
US Government Principles on ENUM
• Preserve national sovereignty on ENUM implementation
• Support competition among all players
• Promote innovation on advanced services
• Protect users’ security and privacy
• Minimize regulation for a global ENUM approach
• Preserve opportunity for alternative deployments
• Allow for interoperability with alternative deployments
• Preserve stability and security of Internet and telecommunications systems
US Government Agencies That May Be Involved in Joint ENUM Effort
• National Telecommunications & Information Administration (NTIA)
• Federal Communications Commission (FCC)
• Federal Trade Commission (FTC)
• Department of State
• Department of Justice
• Department of Homeland Security
It involves numbering, Internet, security and privacy!
Reference Model for End User ENUM Provisioning in the U.S.
Tier 1 Registry
Enum Registrar
ENUMRegistrant orBroker/Agent
Tier 2 Provider
ApplicationServiceProvider
ENUM vs. Existing DNS
• ENUM Registrar must validate ENUM Registrant’s identity and that he/she is indeed the current TN assignee
• Tier 1 Registry, ENUM Registrar and Tier 2 Provider must automatically handle number changes (e.g., area code split, code expansion)
• ENUM Registrant’s right to use an ENUM domain name is tied to if he/she owns/controls the TN– No IPR issue; dispute resolution is simpler
– TN disconnect means no ENUM service on that TN
ENUM is not much different from the existing DNS process except the following:
Benefits of ENUM for Communities of Interest : The Corporate Voice Extranet
• Phone numbers only routable over PSTN network
• Enterprise Dialing plans cannot be accessed by Trading Partners
• Connect “Friends and Family” Customers and Suppliers to Single Dialing plan E.164
ENUM
ENUM Enterprise Architecture Model #1
Enterprise IP PBX to Enterprise IP PBX
ENUM Query by PBX or Edge Proxy
IP Enhanced PBX IP Enhanced PBX
Internet
ENUM
Enterprise Domain Boundary