International Telecommunication Union Global ENUM Implementation DTI ENUM
International Telecommunication Union Global ENUM Implementation DTI ENUM Workshop 5 June 2001 London, UK Robert Shaw <robert. shaw@itu. int> ITU Internet Strategy and Policy Advisor International Telecommunication Union
International Telecommunication Union Caveats • Complex topic • Focused on E. 164 policy and infrastructure issues • ENUM services are primarily national issues – with some exceptions (e. g. , +800) • Work in progress
International Telecommunication Union What is E. 164? • ITU-T Recommendation E. 164: “The international public telecommunication numbering plan” – Tied to treaty obligations (specific roles and obligations defined for ITU Member States and TSB Director) – Defines number structure and functionality for four principal categories of numbers: • • Geographic Areas Global Services Networks Groups of Countries (“Go. Cs”)
International Telecommunication Union Examples of E. 164 Resources • Geographic areas – ITU Member States, including integrated numbering plan involving more than one (e. g. , +1) • Global Services – e. g. , Universal International Freephone Numbers (+800) • Networks – Global Mobile Systems (+881 + 1 digit IC) – Shared code for Networks (+ 882 + 2 digit IC) • Groups of Countries – e. g. , ETNS
International Telecommunication Union Related to E. 164 • ITU-T Recommendation E. 164. 1: Criteria and procedures for the reservation, assignment and reclamation of E. 164 country codes and associated Identification Codes (ICs); • ITU-T Recommendation E. 164. 2: E. 164 numbering resources for trials (to be published); • Determined Recommendation E. 164. 3: Principles, criteria and procedures for the assignment and reclamation of E. 164 country codes and associated identification codes for Groups of Countries (determined at January 2001 meeting of SG 2); • ITU-T Recommendation E. 190: Principles and responsibilities for the management, assignment and reclamation of E-series international numbering resources; • E. 195: ITU-T International numbering resource administration
International Telecommunication Union Issues of Convergence • Problems of addressing calls that pass from one network service to another: – Now widely possible to originate calls from IP address-based networks to other networks – But uncommon to terminate calls from other networks to IP address-based networks – To access a subscriber on an IP address-based network, some sort of global addressing scheme across PSTN and IP address-based networks needed • ENUM may be the “glue” solution…
International Telecommunication Union What is ENUM? • IETF protocol defined in RFC 2916 • E. 164 number used to look up Uniform Resource Identifier (URI) – Web addresses most commonly known URI • Allows using E. 164 number in context of combined PSTN & IP services (email, fax, SIP address, coordinates, IP telephony routing, other? ) • Could be important integrator of PSTN, Internet, and other IP-based networks
International Telecommunication Union What is ENUM? • Protocol uses what are called Naming Authority Pointer (“NAPTR”) DNS resource records as defined in RFC 2915 • Identifies the available methods or services for contacting a specific Internet node identified through an E. 164 number as well as their order of priority/preference: – e. g. , redirect calls, “follow-me” services, contact by email, look up public key, ? ? ?
International Telecommunication Union How would E. 164 numbers be mapped into the DNS? • Reverse map digits in an E. 164 number into separate DNS “names” • Concatenate with “ENUM root zone” (e. g. , foo. tld) • For example: – +33 1 40 20 51 51 = 1. 5. 0. 2. 0. 4. 1. 3. 3. foo. tld • What foo. tld is and how exactly it is administrated is under discussion
International Telecommunication Union Roles and Responsibilities • In telecommunication numbering, regulatory tradition with strong government involvement (e. g. , number portability, antislamming) • In the Internet, management of naming and addressing has been left to “industry selfregulation” • Among early movers, assumption appears to be that national numbering/regulatory authorities will be involved in assisting in ENUM deployment for their portion of E. 164 resources in respective countries
International Telecommunication Union Roles and Responsibilities • Most ENUM service and administrative decisions are national issues under purview of ITU Member States, since most E. 164 resources are utilized nationally • ITU to ensure that Member States have specifically authorized inclusion of geographic country code in the DNS • In integrated numbering plan, each ITU Member State within plan may administer their portion of E. 164 resources mapped into DNS as they see fit
International Telecommunication Union Basic Technical Requirements • Scaleable, robust and secure DNS infrastructure must be provided at all hierarchical levels of the DNS. • Hierarchical registry operations and name servers that coordinate delegations of E. 164 numbering resources will need to be deployed at the international, national and sub-national levels • Important for geopolitical, sovereignty, security and other pragmatic reasons
International Telecommunication Union DNS Infrastructure • To support geographically dispersed national resources, the ENUM root zone foo. tld require DNS backbone dispersed around the world • Main ENUM name servers (e. g. , root zone & CC) should be capable of sustaining loads probably comparable to that carried by current root name servers • Geopolitical and technical constraints need to be balanced (e. g. , limitations of 15 -20 name servers)
International Telecommunication Union DNS Infrastructure • Following principles of E. 164, important to have “country-neutral”, internationally acceptable solution; • History of DNS suggests that transparency needed as to clear legal and policy framework, roles, responsibilities and relationships; • General view that desirable to have one public ENUM name space (one root) • Global infrastructure choices needs to reviewed in this context (e 164. arpa, . arpa name server deployment)
International Telecommunication Union Current. arpa Name Server Deployment
International Telecommunication Union ITU Responsibilities • Operate a registry function or coordinate a registry function for top level of E. 164 • Outsource or coordinate the outsourcing of ENUM name servers corresponding to top level of E. 164 numbering plan • Define and implement administrative procedures that coordinate delegations of E. 164 numbering resources into these name servers
International Telecommunication Union Remaining Issues • Requirement for review of E. 164 legal and policy framework when reflected in DNS? • Without safeguards, ITU Member States will find their E. 164 resources are provisioned or shadowed in “alternative” name spaces outside of their control • Like DNS “country codes”, could E. 164 resources be “marketed” outside their intended geographic/regulatory framework (e. g. , . tv, . md, . ws, . bz)?
International Telecommunication Union Remaining Issues • Privacy – Hardening the ENUM zone data against data mining but hard to stop ENUM name servers being harvested for resources bound to an E. 164 number – Could drive non-DNS based ENUM solution (e. g. , LDAP-based) • Financial operations issues – Major ENUM name servers probably cost US$ 150, 000 -500, 000 per year to operate – ITU Member States & Sector Members need to consider how global infrastructure costs will be shared
International Telecommunication Union ITU Current Activities • Ongoing review of policy and technical issues with assistance of Nominum, Inc. • Preparation of in-depth technical and policy requirements discussion paper • ITU-T SG 2 preparing supplement on issues that need to be addressed by national and international authorities • ITU-T SG 2 Meeting in Sept 2001 • Further discussion with IETF on roles and responsibilities • Plan for testbed countries?
International Telecommunication Union Thank You • References and resources – http: //www. itu. int/infocom/enum/
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