IP-Enabling The Global Telephone Directory ENUM IP-Enabling The Global Telephone Directory Miami, Florida February 12, 2004 Session SP-10 Rom Mattesich, CEO Stratum1, Inc. rmattesich@stratum1.com

E.164 … A Major Accomplishment of the 20th Century Over a billion people can be reached with a single telephone number. E.164 Numbering plan is the “glue” that made complex network connections happen …with one of the simplest user interfaces ever, the 12 digits DTMF pad! … comprehensible in every language known to civilization. 11/11/2018 R. Mattesich

E.164 … Chocking On Its Own Success Tracking a Go-Getter by his business card: Company____________________ Name_______________________ Title________________________ Address_____________________ Reach Info: Main. Tel No:______ E-Mail:_________ Direct Tel No:______ SMS Screen Name:___ Toll Free No:_______ DID for Callback___ Voice Mail:_________ Company URL:____ Fax No:____________ Personal URL:_____ Cellular No1:____________ Cellular No2:____________ Pager No:______________ Home No:______________ 11/11/2018 R. Mattesich

E.164… Chocking on its Own Success(II) Numbers are a scarce resource They are being depleted much faster than population growth Cellular subs/family unit require more numbers/family Number portability escalates consumption of tel. numbers Number of new area codes is multiplying Cost and inconvenience of cutover to new codes are very burdensome to the public. More E.164 digits are almost inevitable! (Four more are possible in the NANP) 11/11/2018 R. Mattesich

Goals Customer should not consume more than one fully qualified E.164 address for each of the many forms of access and services which he/she needs to survive/prosper in the age of convergence and mobility Customers should screen form/time/priority of access at their convenience VoIP will be truly ubiquitous by making the PSTN/Internet transition seamless and transparent to subscribers 11/11/2018 R. Mattesich

ENUM – The Promising Solution The IETF’s ENUM protocol offers the best opportunity for full integration of PSTN and IP Networks by mapping E.164 numbers into fully qualified DNS numbers. The full functionality of the Internet becomes accessible through the simplest device ever, the POTS phone! Communication phone to phone, phone to computer, and/or IP-enabled phones becomes seamless and transparent to users. “Enhanced values” services like Unified Messaging will finally have a chance to blossom Wireless based Internet access much friendlier w/ENUM 11/11/2018 R. Mattesich

A Brief Review- The E.164 NUMBERING PLAN E.164 is the international public telecommunication numbering plan administered by the ITU. It defines number structure and functionality for four principal categories of numbers: Geographic Areas, Global Services, Networks, and Groups of Countries. 11/11/2018 R. Mattesich

Number structure for geographic area E.164 Structure Number structure for geographic area Int’l Access Code (+) Country Specific In US: 011 Country Code/WZ National Destination Code (ndc) cc=1-3 digits(1st=WZ) ndc maximum 15-cc-ndc digits National Significant Number (NSN) International public telecommunication number for geographic areas (maximum 15 digits) Subscriber Number + USA Example 1 305-555 1212 Example of a fully qualified E.164 Number 11/11/2018 R. Mattesich

World Zones - geographic areas E.164 Structure World Zones - geographic areas (1st CC Digit) 1… USA and North America 2… Africa 3… Europe 4… Europe 5… Central and South America 6… Asia 7… Russia 8… Special Services (Inmarsat, FreePhone) 9… Middle East 11/11/2018 R. Mattesich

ENUM – Captures The Power of DNS for Dynamic Addressing What is ENUM? Enum is the name used by the world telephone numbering working group of the IETF to describe a unique method of using the Internet DNS to map E.164 numbers to URL’s. E.164 Number Map Into Uniform Resource Location (URL) 11/11/2018 R. Mattesich

A New Home for ENUM on the Internet… Top Level Domain Names Label Description com Commercial organizations edu Educational institutions gov Government institutions mil Military groups net Network support centers org Nonprofit organizations arpa Internet infrastructure (home for ENUM) int International organizations 11/11/2018 R. Mattesich

An Example of ENUM Mapping Dialed Number’s undergoes following conversions: From + 1-305-555-1212 “Fully Qualified E.164 Number” To 13055551212 “Strip all non digit symbols” To 21215555031 “Reverse string, most important digits read from left to right. Same priority as in URL’s” To 2.1.2.1.5.5.5.5.0.3.1.e164.arpa “Fully qualified URL” The “.” between the digits, create nodes in the DNS hierarchy Responsibility for DNS Admin can now be delegated to successive layer of authority and multiple operators comparable to systems in place for E.164 Admin. 11/11/2018 R. Mattesich

ENUM- Search Algorithm .root 404 Error Internet Resource Not Found Alternate route to PSTN! Top Level Domain Names .arpa .com .uk .int .e164 4.4. (uk) .co .itu 1.nanp 3.3. (fr) (“ARPA” as a TLD is a subject of some international controversy) 8.8.0.1.6.3.4.5.0.3. for 305-436-1088 11/11/2018 R. Mattesich

ENUM Builds Upon the Power of DNS A FQDN Query to DNS produces an “A” record, which returns an IP Address, e.g., Yvonne@company.com 129.171.15.23 An ENUM call to DNS (2.1.2.1.5.5.5.5.0.3.1.e164.arpa), allows Yvonne to advertise a number of services. Examples: $ORIGIN 2.1.2.1.5.5.5.5.0.3.1.e164.arpa “Yvonne’s the owner” IN NAPTR 100 10 “u” “sip+E2U” “!^.*$!sip:yvonne@sip.company.com!” “Phone me via SIP” IN NAPTR 100 10 “u” “mailto+E2U” “!^.*$!mailto:yvonne@mail.company.com!” “or email me” IN NAPTR 100 10 “u” “http+E2U” “!^.*$!http://www.yvonne.company.com!” “look me up in my personal web site” IN NAPTR 103 10 “u” “tel+E2U” “!^.*$!tel:+1305-555-9999!” “Try me on the cellular” URI Control Characters Above services are all available from a single number 11/11/2018 R. Mattesich

Dialing an IP-Enabled Phone... The ENUM Way DNS Servers 4. DNS Server returns NAPTR sip: yvonne@company.com 6.DNS responds w/A Record 12.12.12.1 3. Sip gateway queries 2.1.2.1.5.5.5.5.0.3.1.e164.arpa 5.Gateway selectsNAPTR sip:yvonne@company.com Yvonne PSTN IP Network Xavier IP SIP Server for 12.12.12.1 Sip Gateway 2. PSTN maps and routes Yvonne’s E.164 number to near-end gateway. IP Phone 305-555-1212 7..Gateway completes call To SIP port on server 12.12.12.1 1. Xavier single stage dials Yvonne at 1-305-555-1212 Above communication is seamless and transparent to both X & Y SIP Gateways dips into DNS twice: (1) Get List of Yvonne’s Services (2) Selected service is sent back to DNS to get destination IP (A Record) 11/11/2018 R. Mattesich

ENUM – The Promise and The Bane ENUM essentially maps a multiplicity of services to a single telephone number Creation/Provision of these services is an edge function… not embedded in the network, such us with IN/SS7/SCP. The transformation is profound: value added services such as call forwarding, number translation, conference calling, and many more, will be created by enterprises and consumers, not telephone companies! 11/11/2018 R. Mattesich

Who Owns The Numbers? ENUM’s records point to traditional telephony as well as to all sorts of Internet services. Telephony, as well as ISP’s, may claim rights to blocks of numbers. Consumers may want to demand different services (under the same ENUM) from different providers. One ENUM can point to multiple providers. 11/11/2018 R. Mattesich

Conceptual ENUM Admin Hierarchy Goal: Promote Competition w/o Chaos. Tight administrative coupling is necessary between E.164 and ENUM Registries Most Likely Assignee: E164Country Registrar (NeuStar in the USA) Fully Competitive Level 11/11/2018 R. Mattesich

ENUM Raises Important, Unresolved Social Issues Privacy: Democratic countries (US in particular) shun One Number ID. A popular Internet command (WHOIS) reveals much contact info about registrant ENUM Info needs some protection from third parties Consequences of spammers/pornographers getting hold of ENUM data can be devastating to users See ENUM – A Case Study in Social Irresponsibility These issues are still being debated, but value of ENUM is so compelling that most problems are likely to be resolved soon. 11/11/2018 R. Mattesich

ENUM… A Knowledge Base on The Internet Check up some useful document/web sites to get more info: RFC 2915: http://www.ietf.org/rfc/rfc2915.txt RFC 2916: http://www.ietf.org/rfc/rfc2916.txt ENUM working group charter: http://www.ietf.org/html.charters/enum-charter.html SIP working group charter: http://www.ietf.org/html.charters/sip-charter.html Web site for IANA: http://www.iana.org Web site for ICANN: http://www.icann.org International Telecommunications Union (ITU): http://www.itu.int Search for E.164 11/11/2018 R. Mattesich

Who Is Behind ENUM? IAB US EU France Sweden Switzerland Austria Korea Companies Standard Bodies Countries US EU France Sweden Switzerland Austria Korea Australia NeuStar Verisign AT&T Telcordia Cisco IAB IETF ITU 11/11/2018 R. Mattesich

Implementations of ENUM and ENUM-like systems: US NeuStar’s Public Trial (www.enum.org) Verisign’s WebNum (www.webnum.com) Netnumbers (www.netnumber.com) ENUMNic (www.enumnic.net) ENUMWorld (www.enumworld.com) 11/11/2018 R. Mattesich

Implementations of ENUM: Other Countries France: Numerobis http://www.telecom.gouv.fr/rnrt/projets/res_02_44.htm Austria: Austria ENUM Site http://enum.nic.at/ Korea: KRNIC http://www.enum.or.kr/ Sweden: Post and Telestvrelsen http://www.pts.se/tele_niva3.asp?avdelning=lev3_enum&uavdelning=tele_niva3&u2avdelning=workshop&lang=&header=Can Switzerland: Swiss Federal Office of Communications (OFCOM) http://www.ofcom.ch/en/telekommunikation/nummerierung/enum/index.html 11/11/2018 R. Mattesich

Some Key Terms Related to ENUM DNS Domain Name System NS Name Server (for a domain) NAPTR Naming Authority Pointer URI Uniform Resource Identifier URL Uniform Resource Locator E2U E.164 to URI conversion $ORIGIN followed by originating domain name SIP Session Initiation Protocol (similar to HTTP) popular for VoIP PSTN Public Switched Telephony Network IETF – Internet Engineering Task Force is an international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the Internet. Any questions? 11/11/2018 R. Mattesich