SG-A Ad Hoc - ENUM Jordyn A. Buchanan Register.com February 12, 2001

Multi-tiered ENUM administration model likely All current administrative models include multiple tiers Good operational experience –Global TLDs –Local Number Portability

Various Tier I Models under discussion e164.arpa as a monolithic, authoritative ENUM hierarchy Competitive ENUM registries Distributed but collaborative registries

An authoritative ENUM top-tier is likely to emerge DNS does not lend itself well to searches across multiple data stores without an authoritative root Consumers will demand –Consistency : similar lookups should return similar results –Usability : disparate data sources require complex configurations Authoritative top-tier could be relatively unregulated, a loose co-ordination of competitive registries Private ENUM hierarchies will exist, but are likely to be self-contained (similar to Intranets)

Tier Is Limited Role Straightforward data management regime Little or no interaction with end-user Limited scope of data Analogies: NeuStars administration of the North American Numbering Plan, VGRS administration of.com,.net, &.org.

Tier II becomes the focus Face of ENUM to the end user Handles user data, must deal with privacy issues May be bundled with value-added services to the consumer Important to understand policy options at this layer in addition to global/Tier I issues Robust tier II competition may obviate the need for multiple options at Tier I Robust tier II market increases Tier Is reach

Tier II administration options Domain name registrars Telephone service providers (TSPs) Model similar to RespOrgs in US 1-800? Others?

Tier II Role Sales and marketing efforts to end users Gather information regarding authoritative nameservers and enter into Tier I registry Host NAPTR records Co-ordinate between ASPs and end-users to provision ENUM-related services

TSPs as Tier II Admins TSPs responsible to manage ENUM for E164 numbers they provide services for Integrated service offering including: –Hosting of NAPTR records –Telephony services

TSPs as Tier II Admins : Advantages Simplicity –One administrator for both telephone number and associated ENUM –No need to create external mechanism for verfication and disconnect notification Clear incentive for TSPs to develop verification infrastructure Better understanding of telecom issues

TSPs as Tier II Admins: Disadvantages High barriers to entry In areas served by a single carrier, no competition for ENUM services TSPs have incentives to limit competition –May not provision applications which compete with their service offerings Historically, large amounts of fraud from unscrupulous providers

Domain Registrars as Tier II Admins Existing pool of domain registrars expands their services to include ENUM registration Registrars also act as service registrars and host NAPTR records directly Must establish verification mechanism to confirm authenticity of requests

Domain Registrars as Tier II Admins: Advantages Large global pool of existing competitors Relatively simple extension of existing business models –Experience with DNS systems –With the exception of verification mechanism, ENUM registration is identical to domain name registration Low barriers to entry Faster adoption : individual TSPs do not have to implement ENUM technology for the service to become available nationwide

Domain Registrars as Tier II Admins: Disadvantages Creation of disconnect notification and verification system is required Many registrars have limited exposure to telecom issues

Other Options Creation of model similar to RespOrgs used in US service Allow competition between TSPs, domain registrars, and others These options generally look a lot like domain registrars, with different accreditation criteria

Consumers Should Retain Control of ENUM resources Privacy : end-users should be able to opt-in, opt- out and modify data within ENUM at will Consumer choice encourages the development of new features, better prices Potentially allows ENUM to facilitate telecom competition As with service, prevents conflicts of interest

Verification/Disconnect Notification Required to verify the validity of ENUM subscription/modification requests TSP incentives to create –Prevents hijacking of subscribers numbers –Allows TSPs to fully reclaim numbers upon disconnect Alternate approach: require verification only when conflicts exist –Allows for easy start-up, straightforward registration –Establish authentication mechanism upon initial registration –Significant potential for hijacking, probably unacceptable Verification mechanism should be available to all qualified Tier II entities May require regulatory action

Broad Competition at Tier II Seems Ideal Separation of Tier II registration functions from TSP functions allows consumers to easily migrate between service providers and between service registrars Supports consumer choice as driver for ENUM decision-making Accreditation criteria should allow TSPs, domain registrars, and others to compete effectively and leverage relevant experience

Next Steps Development of verification / disconnection notification system Identify types of entities that should be allowed to be a Tier II registrar Industry testing of Tier II registrar implementations