1. ETSI ENUM Workshop – February 2004 Carrier ENUM – NeuStar’s experienceMarco Bernardi James Yumarco.bernardi@neustar.bizjames.yu@neustar.biz

2. NeuStar’s mission http://www.neustar.biz • NeuStar is the leading provider of database, clearinghouse and registry services that enable network operators and service providers to interoperate • NeuStar is a neutral trusted third party • 350 employees. HQ in Washington DC area • NeuStar main areas • Registry services: North American Numbering Plan, Numbering Pooling, ETNS, .biz, .us, gateway for.cn, .tw • US Number Portability Administration Center (NPAC) • Convergence IP and PSTN: ENUM • OSS clearinghouse services

3. What’s carrier ENUM for? • Used to retrieve routing and addressing information associated with E.164 number • Carrier ENUM is transparent to users • In mobile networks carrier ENUM can be used for: • Inter-carriers MMS routing (identify home MMSC) • Inter-carrier SMS routing (identify home SMSC or SMPP GW) • MNP data retrieval (identify routing number/prefix) • SIP server resolution (identify home SIP servers) • Network node identification (identify HLR/HSS, P-CSCF) • Trusted transaction roaming (identify home MSSP)

4. Inter-carrier MMS routing • Problem statement • Resolution of MMSC based on MSISDN in MNP environment • Analysis of leading digit of MSIDN is not enough • Solutions • Query the HLR to retrieve and use IMSI to identify the home carrier/MMSC • Use carrier ENUM to identify home carrier/MMSC

5. Multimedia message delivery using carrier ENUM B’s MMSC A’s MMSC 2 3 (MM4 Interface) 4 5 1 A B 1. A sends a message to B’s MSISDN and the message is sent to A’s MMSC. 2. A’s MMSC uses B’s MSISDN in the ENUM query. 3. NeuStar returns the NAPTR RR that contains a mailto URL. 4. A’s MMSC determines the MMSC serving B and sends the message to B’s MMSC. 5. B’s MMSC sends a notification to B.

6. Overview of NeuStar’s trials • NeuStar’s carrier ENUM trial • Phase I - National • Started in Spring 2003 and concluded in October 2003 • Two major US carriers involved • Proved commercial and technical feasibility • Signed commercial agreement with these two US carriers after trial • Phase II – International • Ongoing with other US carriers • Extended to non-US carriers • Include MSISDNs other than “+1” numbers

7. Key features (I) • Application • Resolution of MMSC in MNP environment • Reference model • Tier1 Registry knows MNP data and number range assignment data • No involvement of NRH Carrier • NAPTR record at individual E.164 number level • Two options • 1) NeuStar is only Tier1 Registry, NAPTR records stored by carrier • 2) NeuStar is Tier 1 Registry and stores NAPTR records

8. Key features (II) • Option 2 seems to be the preferred one • Less work for the carrier • The carrier is the registrar • The carrier decides the level of information to be stored in NAPTR Record associated to an MSDIN • MMSC address • Identification of mobile carrier/PoI (minimum info) • No Validation/Authentication Agency • Number ownership automatically verified based on MNP and code range assignment data • No accreditation

9. NAPTR format Example 4.3.2.1.1.8.9.3.0.7.1.foo.foo IN NAPTR 10 10 “u" “E2U+mms" “!^.*$!mailto:+17039811234@xyz.com!” . NP Data NeuStar 4.3.2.1.1.8.9.3.0.7.1.foo.foo Requesting MMSC Other Data NAPTR RR(s) Example: Carrier XYZ currently serves +1-703-981-1234, which can be ported or non-ported. When an MMSC sends a query on “4.3.2.1.1.8.9.3.0.7.1.foo.foo,” NeuStar NTS responds with an NAPTR RR that contains a “mailto” URL, “mailto:+17039811234@xyz.com.” The MMSC then uses the information to send the message to Carrier XYZ’s MMSC.

10. Architecture of NeuStar ENUM trial Carrier 1 VPN VPN NTS1 NTS2 Carrier 2 VPN IP backbone VPN Carrier 3 NTS = Number Translation Service Carrier N

11. Carrier ENUM - Merits • Proven DNS technology • Cheap to support and quick to implement • Can grow over time - no need to have everybody onboard on day one • No end user/subscriber involvement • Used by carriers for routing and application support • Same infrastructure/scheme supports multiple applications

12. What’s next…. • Fragmentation and proliferation of carrier ENUM implementations • Vendor level Different providers offering different services by using different technical solutions • Industry sector level  Fixed and mobile • No need for a common administrative and operational framework • May need for consistent URL contents/formats for various applications/services globally • Market forces will determine the preferred solution(s) • ETSI PlugTest may help vendors and carriers to get together and test carrier ENUM functionalities

13. Questions ?