An Evolution Path for Numbering and Interconnection

1. An Evolution Path for Numbering and Interconnection Future Of Numbering Symposium November 4, 2004 Presented by Penn Pfautz

2. Don’t Count NANP Numbers Out • Excitement about role of IP addresses/”handles” is interesting, and will be key in some applications, but …. • Telephone numbers aren’t going away • Key pads limit alphabetic entry • Numbers support customer demands for privacy • Ubiquity of telephone numbers in telephony and non-telephony systems makes numbers hard to give up • BUT, the role of numbers in actual routing will diminish as telephony becomes an application on IP networks

3. Numbering & Interconnection • Numbers are about interconnection • NPA-NXX defines point of interconnection, not end user location • Point of Interface (POI) model lets users move without impacting calling party billing or carrier settlements • Wireless and foreign exchange service are existence proofs for the POI model • IP will change interconnection • All numbers will be 10-digit translated

4. The Triad • Three potential developments could revolutionize the current paradigm for numbering and interconnection • Internet Interconnection • Infrastructure ENUM • Individual Telephone Number Pooling

5. The Evolution of Interconnection • Circuit-switched interconnection model • Of necessity bilateral • Currently makes arbitrary distinctions between technically equivalent traffic types for MOU charges to provide subsidies • Intercarrier Compensation Forum reform proposals already contemplate transition to Bill & Keep • IP interconnection model • Based on peering or purchase of Internet access • Any public IP address reachable by any party with Internet access Which direction will VoIP interconnection take?

6. Internet Interconnection • All carriers provide at minimum a point of interconnection accessible through the Internet • Point or points to which SIP INVITEs and bearer traffic can be delivered • Alternate arrangements may be negotiated • Can be accomplished by purchase of gateway and ISP access where a carrier lacks its own IP network • Will only carriers or any entity be allowed to deliver traffic?

7. Infrastructure ENUM • Carriers provide ENUM entries with their Internet POI for numbers they serve • Separate from end user opt-in ENUM • Could replace number portability databases for Toll-Free as well as geographic numbers) • Tier 1 Registry could replace NPAC, SMS 800, perhaps LERG • Actual routing data under carrier control in Tier 2

8. Individual Telephone Number Pooling • As with toll-free, numbers not in service or aging are available to all carriers • More efficient utilization of resources since block size=1 • NRUF, code/block acquisition processes eliminated since Registry provides support for measurements, resource assignment • Supports TN-based USF reform

9. In an IP environment many of the problems of implementing ITN in legacy networks are mitigated • LRNs (and thus NPA-NXX assignments) no longer required since routing is based on ENUM translation to Internet address • Price curve for VoIP technology will make it affordable for even small/rural carriers

10. Conclusion • Many oxen gored but, • Highly efficient structure based on Internet concepts replaces many unwieldy industry processes (could even add Do Not Call registry) • Significant conservation benefits • Fosters competition • Transition would take time but market forces will drive in this direction