1. Copyright GSM Association 12 March 2007 PT 2 TRIS Copenhagen Meeting 22-23 March 2007 Security Classification Category - Unrestricted – GSMA Members and non-Members GSMA ENUM Project Overview Robindhra Mangtani, Director Interworking and Roaming Restricted Confidential - Information Access to and distribution of this document is restricted to the persons listed under the heading Security Classification Category*. This document is confidential to the Association and is subject to copyright protection. This document is to be used only for the purposes for which it has been supplied and information contained in it must not be disclosed or in any other way made available, in whole or in part, to persons other than those listed under Security Classification Category* without the prior written approval of the Association. The GSM MoU Association (“Association”) makes no representation, warranty or undertaking (express or implied) with respect to and does not accept any responsibility for, and hereby disclaims liability for the accuracy or completeness or timeliness of the information contained in this document. The information contained in this document may be subject to change without prior notice. © Copyright of the GSM Association 2007

2. Copyright GSM Association GSMA Plans for ENUM 2 Who/What is the GSMA Represents the interests of GSM Operators globally –GSM, GPRS, EDGE, W-CDMA technologies Formed primarily of operators. As at Nov 2006: –Full Members: 711 operators –Associate Members: 191 manufacturers & suppliers, –Members located in: 215 countries/territories ENUM Group is one of a number of technical working groups GSMA groups take the output from standards bodies and facilitate operators agreeing how their networks will interwork: settings, conventions etc GSMA groups create PRDs (Permanent Reference Documents) describing rules, guidelines and options for all aspects of Interworking

3. Copyright GSM Association GSMA Plans for ENUM 3 What is ENUM A database, or series of databases, that returns a URI associated with a telephone number Enables operators to offer subscribers the ability to send e-mails, MMS or initiate Personal IM sessions with other mobile or landline users, even though the caller only knows the telephone number of the receiving party (rather than e-mail address or Personal IM username) ENUM converts phone numbers into email-like addresses +447777123456 to identifier@network.com identifier@network.com Need ENUM for IP services where the customer/terminal needs to use a phone number but the underlying network only understands email-like addresses for routing. Example services: instant messaging, video Technically –E.164 telephone number (MSISDN) Number Mapping (to IP address URI ) –Utilising Internet Engineering Task Force (IETF) standard, and –Domain Name Service (DNS) software for address query and resolution

4. Copyright GSM Association GSMA Plans for ENUM 4 ENUM Model GSM community is proposing an optional "On-Net" business model for use by any organisation, not just mobile operators Operators can choose whether to use the "On-Net" model or "Off-net" model, or bi-lateral direct connections or any combination of these "On-Net" Model uses the IPX (IP Interworking Exchange) which builds on the existing GRX IP network. The GRX is today used primarily for GPRS & 3G roaming. The name "IPX" may change in future Carrier ENUM is built for use by "On-Net" operators only IPX & ENUM described here are "work in progress"

5. Copyright GSM Association GSMA Plans for ENUM 5 GSMA Service Framework IPX (Managed) with Carrier ENUM available Third Party Provider Third Party Subscriber Public Telecomms Networks Mobile Subscribers Fixed Network Corporate Network “On-Net” Services “Off-Net” Services Internet Third Party Provider Fixed Network Corporate Network Public Telecomms Networks Service Level Inter-working: - End-to-End service control - Managed access (3 rd party) - Service level (value) accounting - Calling Party Pays Network Level Inter-working: - Best effort, “Bit pipe” transport - No effective access control - Network level accounting (time/volume) - Mobile Party Pays "Single root" ENUM System Fixed line Subscribers V-o-IP Subscribers Mobile Subscribers Fixed line Subscribers V-o-IP Subscribers Direct IP Connection(s) Direct Connection: - Operators free to choose whichever model they wish Carrier ENUM (e164enum.net) ENUM Service Providers

6. Copyright GSM Association GSMA Plans for ENUM 6 Carrier ENUM Details "Single Root" Carrier ENUM available in IPX network For use by "On-Net" operators only Single private domain Not connected to Internet DNS e164enum.net domain for ENUM information –i.e. not using e164.arpa for ENUM Intended to be available for global use by any operator, mobile or fixed, who wishes to connect Will be primarily used by IMS and MMS services Documented in IR.67 DNS Guidelines –Updated unrestricted version available soon on GSMA public web site: http://www.gsmworld.com/

7. Copyright GSM Association GSMA Plans for ENUM 7 Benefits of Proposed Approach Highest performance and quality of customer calls/services possible due to end-to-end management Increases range of services available to customer for them to choose Better security for decreasing the risk of spam, Denial- of-Service attacks, identity fraud etc Minimised privacy concerns about numbering and related data because IPX is private and not accessible by end users Excellent global reach: Carrier ENUM will have large quantity of numbers available, particularly mobile numbers as operators opt into the system (over 2.2 billion GSM customers today)

8. Copyright GSM Association GSMA Plans for ENUM 8 Number Portability and ENUM ENUM Number administration is an area of significant interest and concern Today approximately 40 countries/jurisdictions operate number portability Majority of countries have central organisations that operate a Number Portability (NP) database Some countries operate a "distributed" NP model without a central organisation ENUM can work with either model (central/distributed) Some jurisdictions/countries may: –choose to apply charges for ENUM queries –require competition between multiple ENUM providers Competition impacts the DNS model

9. Copyright GSM Association GSMA Plans for ENUM 9 Traditional DNS Hierarchy for ENUM Master Root Server (Tier 0) Secondary Root Server (Tier 0) DNS (Tier 2) Secondary Root Server (Tier 0) DNS Server (Tier 1) DNS (Tier 2) One Master Root (Tier 0) DNS Server (Tier 1) Multiple Secondary Roots (Tier 0) per network (Tier 1) Master & Slaves typically per country (Tier 2) Master & Slaves typically per operator or centralised and shared "Single Root" Model

10. Copyright GSM Association GSMA Plans for ENUM 10 Carrier ENUM Database ENUM descriptions often include an "ENUM Database" which is built using DNS structures But: existing Number Portability databases in 30+ countries represent a huge investment - must be kept The "ENUM Database" is expected in practice to be the existing (or upgraded) Number Portability database with an ENUM query interface added Authoritative Numbering Data ENUM query ENUM server C7 query C7 server Numbering query Operator A Operator B Traditional Switch SIP Server "Number Portability" database Numbering Update Processes Updates New Numbers and "ports" between operators "ENUM Database"

11. Copyright GSM Association GSMA Plans for ENUM 11 "Single-root" Carrier ENUM IPX Network Slave Root Server (Tier 0) Master Root Database Slave Root Server (Tier 0) Country YCountry Z Fixed Operator Mobile Operator Mobile Operator Central Authority ENUM Server (Tier 1 and Tier 2) Mobile Operator ENUM (Tier 2) Fixed Operator ENUM (Tier 2) ENUM Server (Tier 1) Central Authority Master Number Data Country X Master Number Data Mobile Operator ENUM Server (Tier 1 and Tier 2) Shows possible examples of the DNS hierarchy which will vary by country / jurisdiction Master Number Data Master Number Data Master Number Data Master Root Server (Tier 0) The root data is normally stored in a database and the DNS datafill generated when the DNS is updated

12. Copyright GSM Association GSMA Plans for ENUM 12 Centralised resources The design of Carrier ENUM requires some kind of central resource in each country/jurisdiction: –Either: the whole number database (central model) –Or: pointers to sections of the number database (distributed model) Some countries may choose to offer a centralised ENUM service to all operators Some countries may offer ENUM service only via a third party "ENUM Service Provider" Some countries/jurisdictions may require ENUM service is offered via competing "ENUM Service Providers"

13. Copyright GSM Association GSMA Plans for ENUM 13 Possible ENUM Business Models (Major ENUM Query options in a country/jurisdiction, not a complete list) Operator 1 Operator 2 ENUM Server (Tier 1 and Tier 2) Authoritative Numbering Data Shared Central Authority Operator 1 Operator 2 Shared Central Authority ENUM (Tier 2) Authoritative Numbering Data Authoritative Numbering Data ENUM Server (Tier 1) Authoritative Tier 1 Data Operator 2 Operator 3 Authoritative Numbering Data Shared Central Authority ENUM Service Provider 2 ENUM Server (Tier 1 and Tier 2) ENUM Service Provider 1 ENUM Server (Tier 1 and Tier 2) Operator 1 Competing third party ENUM Service Providers Distributed ENUM Database Operator 1 Operator 2 Authoritative Numbering Data Shared Central Authority Local Copy of data and ENUM interface Centrally-run ENUM Database ENUM Server (Tier 1 and Tier 2) ENUM Server (Tier 1 and Tier 2) (Local Copy) Numbering Data Copy Numbering Data Copy Enum Query Numbering Query Copy Data (Local Copy) Numbering Data Copy Numbering Data Copy

14. Copyright GSM Association GSMA Plans for ENUM 14 Competition - ENUM Impact Problem: Requirement for competing Service Providers is incompatible with traditional DNS model "Single root" DNS Model is simple but permits only one ENUM provider in every country –If there is competition "Single root" favours one provider –Favouring is unacceptable, so "Single root" model cannot be used in this case for locating ENUM data Solution: Where a country has multiple ENUM Service Providers anyone making an ENUM query to that country must make a specific choice of ENUM provider –Sometimes called the "no root" model "Single root" may be used to locate ENUM data in other countries that have only one source of ENUM data

15. Copyright GSM Association GSMA Plans for ENUM 15 ENUM Query models - Competition Use of competing ENUM Service providers in Country Q Root Database Mobile Operator Central Authority DNS Server (Tier 1 and Tier 2) Country X - linked into Single root Root Server (Tier 0) Global "Single Root" Carrier DNS+ENUM DNS Queries In this model there are competing ENUM providers in Country Q. Because there are multiple sources of ENUM data there can be no link into the central root because if there was, one ENUM Provider would be favoured. An Operator needing ENUM data from Country Q must make their own choice of ENUM provider The DNS's are all configured to work in iterative mode only which means that the DNS making the query has to do all the querying itself. Central Database Central Authority Country Q ("No Root" - not linked into Single root) Specific choice of ENUM Provider (can use DNS Forward to achieve this) "Default" choice of ENUM server Country Z - linked into Single root ENUM Server (Tier 1 and Tier 2) Number Database ENUM Service Provider 1 ENUM Server (Tier 1 and Tier 2) ENUM Service Provider 2 ENUM Server (Tier 1 and Tier 2) Query via Single Root DNS Hierarchy Database Interface Query to "No Root" Mobile Operator This operator uses ENUM SP 2 for all their ENUM lookups

16. Copyright GSM Association GSMA Plans for ENUM 16 ENUM Charging Principles The cost of running the ENUM system in each country/jurisdiction will need to be recovered somehow ENUM charging principles could follow one of the examples below (or could be a combination) This is an area for further study ExampleWho PaysBasis of Charge 1.Calling network (or their agent) Per ENUM Query 2.Calling network (or their agent) "Unlimited queries" e.g. annual charge. 3.Receiving networkPer call charge. 4.Receiving network"Unlimited queries" e.g. annual charge.

17. Copyright GSM Association GSMA Plans for ENUM 17 Summary GSMA proposes an "On-Net" business model for any organisation to use, not just mobile operators. Operators can use this model, or Internet, or direct connections, or any combination of these. "On-Net" business model promotes competition and increases choice of services available to customers Facilitates national and international interworking for IMS & MMS services today and others in future Protects customers from spamming and identity fraud e164enum.net domain will be used for Carrier ENUM Countries may operate with or without competing ENUM SPs and these approaches can interwork This work is "in progress", not complete.