digplanet beta 1: Athena
Share digplanet:


Applied sciences






















E.164 is an ITU-T recommendation, titled The international public telecommunication numbering plan, that defines a numbering plan for the world-wide public switched telephone network (PSTN) and some other data networks.

E.164 defines a general format for international telephone numbers. Plan-conforming numbers are limited to a maximum of 15 digits.[1] The presentation of numbers is usually prefixed with the character + (plus sign), indicating that the number includes the international country calling code (country code), and must typically be prefixed when dialing with the appropriate international call prefix, which is a trunk code to reach an international circuit from within the country of call origination.

The title of the original version and first revision of the E.164 standard was "Numbering Plan for the ISDN Era".

Telephone number categories[edit]

This recommendation provides the number structure and functionality for the three categories of telephone numbers used for international public telecommunication:

For each of the categories, it details the components of the numbering structure and the digit analysis required to successfully route the calls. Annex A provides additional information on the structure and function of E.164 numbers. Annex B provides information on network identification, service parameters, calling/connected line identity, dialing procedures, and addressing for Geographic-based ISDN calls. Specific E.164-based applications which differ in usage are defined in separate recommendations.

The number categories are all based on a fifteen-digit numbering space. Before 1997, only twelve digits were allowed. The definition does not include any trunk dialing codes, necessary for a call to reach international circuits from inside the country of call origination.

Number structure for geographic area[edit]

Country Code National Destination Code (optional) Subscriber Number
National (significant)
cc = 1 to 3 digits maximum = 15 − cc = 12 to 14 digits
International public telecommunication number for geographic areas (maximum 15 digits)

Number structure for global services[edit]

Country Code Global Subscriber Number
cc = 3 digits maximum = 15 − cc = 12 digits
International public telecommunication number for global services (maximum 15 digits)

Number structure for networks[edit]

Country Code Identification Code Subscriber Number
cc = 3 digits x = 1 to 4 digits maximum = 15 − (cc + x) = 8 to 11 digits
International public telecommunication number for networks (maximum 15 digits)

Number structure for groups of countries[edit]

Country Code Group Identification Code Subscriber Number
cc = 3 digits gic = 1 digit maximum = 15 − (cc + gic) = 11 digits
International public telecommunication number for groups of countries (maximum 15 digits)



This recommendation describes the procedures and criteria for the reservation, assignment, and reclamation of E.164 country codes and associated identification code (IC) assignments. The criteria and procedures are provided as a basis for the effective and efficient utilization of the available E.164 numbering resources. Such assignments require a collaborative effort between the ITU-TSB and the appropriate ITU-T study group to endeavor to ensure that the assignments meet the needs of the telecommunication community. The development of these criteria and procedures are in accordance with the principles contained in E.190 and the numbering plan formats detailed in E.164.


This recommendation contains the criteria and procedures for an applicant to be temporarily assigned a three-digit identification code within the shared E.164 country code 991 for the purpose of conducting an international non-commercial trial.


This recommendation describes the principles, criteria, and procedures for the assignment and reclamation of resources within a shared E.164 country code for groups of countries. These shared country codes will coexist with all other E.164-based country codes assigned by the ITU. The resource of the shared country code consists of a country code and a group identification code (CC + GIC) and provides the capability for a group of countries to provide telecommunication services within the group. The TSB is responsible for the assignment of the CC + GIC.


E.163 was the former ITU-T recommendation for describing telephone numbers for the public switched telephone network (PSTN). In the United States, this was formerly referred to as a directory number. E.163 was withdrawn, and some recommendations were incorporated into revision 1 of E.164 in 1997.

DNS mapping of E.164 numbers[edit]

Some national telephone bodies or telephone companies have implemented an Internet-based database for their numbering spaces. E.164 numbers may be used in the Domain Name System (DNS) of the Internet in which the second-level domain e164.arpa has been reserved for telephone number mapping (ENUM). In the system, any phone number may be mapped into a domain name using a reverse sequence of subdomains for each digit. For example, the telephone number +19995550123 translates to the domain name[2]

When a number is mapped, a DNS query may be used to locate the service facilities on the Internet that accept and process telephone calls to the owner of record of the number, using, for example, the Session Initiation Protocol (SIP), a call-signaling VoIP protocol whose SIP addresses are similar in format (user@domain...) to e-mail addresses.

This allows a direct, end-to-end Internet connection without passing to the public switched telephone network (and back) and without incurring PSTN tolls.

As this is effectively a free call, there is little incentive for carriers to promote e164 DNS service. The e164.arpa domain is in production status as of 2013 only in a few European nations (Austria, Czech Republic, Finland, Germany, Ireland, Lithuania, Poland, Romania, Netherlands, United Kingdom).[3] Australia conducted a trial in 2007, but then abandoned further support of.1.6.e164.arpa.[4] Many nations have no .e164.arpa implementation active.[5]

The Internet Telephony Users Association runs e164.org as an alternate server, which relies on users submitting their own PSTN numbers and corresponding URIs for verification.[6] A VoIP PBX, such as Asterisk, may be configured to resolve numbers in both databases, sending only those not listed with a free Internet routing over the PSTN.

See also[edit]


  1. ^ ITU; ITU-T. "The International Public Telecommunication Numbering Plan". ITU. p. 11. Retrieved 21 March 2014. 
  2. ^ "ENUM —Mapping the E.164 Number Space into the DNS". The Internet Protocol Journal - Volume 5, Number 2. Cisco Systems. Retrieved 2013-10-26. 
  3. ^ "RIPE ENUM Working Group: Progress Matrix". Enumdata.org. Retrieved 2013-10-26. 
  4. ^ "ENUM trial". enum.com.au. Retrieved 2013-10-26. 
  5. ^ Russell Bryant, Leif Madsen, Jim Van Meggelen. Asterisk: The Definitive Guide. Retrieved 2013-10-26. 
  6. ^ Joshua Brashars (2007-08-13). Asterisk Hacking. Retrieved 2013-10-26. 

External links[edit]

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/E.164 — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
1000000 videos foundNext > 

Is David Cameron The Terrorist? Russell Brand The Trews (E164)

Russell Brand The Trews (E164). In this Trews special I'm joined by actor ALEC BALDWIN, plus Max Keiser and Stacy Herbert of 'The Keiser Report', discussing ...

questoes 163 e 164

Beach Detecting With Deep Digger Daughter & E Trac (164)

So it's time to unwrap the E Trac and see what it can do on the beach. Deep Digger Dan Shop: http://deepdiggerdanshop.com Facebook: https://www.facebook.com/...

Luis Carlos FURBINO vôos 163 e 164 na Caixa d'agua e em Timbuí ES

46:56 minutos de vôo com 723 metros de altitude.

Provet TV: May 19th, 2014 E.164

Kasey and Flora give you the latest update on campus news.

felipe e 164

Formatura da RIA 163 e 164

K! KTH T V with dave E 164 www facebook com daichishibuki twitter @dave daviz sana po ay panuurin

Bibla, fjalë e Zotit apo e njeriut ? ( pjesa e 164 ) Cilët ishin vizitorët e parë ? 2

Kontradikta numer 164.

"독도는 우리 땅!" 외치는 귀화 일본인 교수.박종진의 쾌도난마 E164.120815

공식홈페이지 : http://tv.ichannela.com/culture/sisatalk 최신영상 더보기 : http://tv.ichannela.com/culture/sisatalk/vod/ [박종진의 쾌도난마] 2012/08/15방송 164회 ▷"독도는 우리 땅!" 외치는 귀화 ...

1000000 videos foundNext > 

10136 news items

PC Pro
Wed, 06 Nov 2013 01:40:19 -0800

The E.164 format shows what you need to dial to reach that phone from any other phone on the planet. All the different telco regulators specify how phone numbers must work within their respective jurisdictions, but E.164 is the overarching standard.
La Prealpina
Wed, 26 Nov 2014 03:15:00 -0800

Per queste persone che rischiano lo sfratto e accumulano debiti, la Regione Lombardia ha deliberato alcune iniziative a sostegno che devono essere tradotte in pratica dai Comuni. A Varese, sono stati assegnati, per quest'anno, oltre 181mila e 164 euro.
Mon, 24 Nov 2014 07:33:45 -0800

E secondo le ultime cifre disponibili (2012), 422 donne hanno donato ovociti e 164 bambini sono nati, mentre 2.110 coppie erano ufficialmente in attesa di una donazione. Per quanto riguarda gli spermatozoi, sempre nel 2012, 235 uomini hanno fatto ...


Sat, 22 Nov 2014 05:19:20 -0800

“Antes eu deixava nas bibliotecas dos terminais do sistema Transcol, mas passou a ficar difícil eu me locomover até lá, então passei a deixar nos ônibus que eu circulo mesmo, que geralmente são as linhas 112, 103 e 164”, disse. E foi por meio das ...
Thu, 27 Nov 2014 01:33:45 -0800

 Domani, giovedì 27 novembre, alle 11.00, presso il Fortino Sant'Antonio, alla presenza dell'assessore al Welfare Francesca Bottalico, sarà inaugurata la mostra fotografica itinerante "50 anni di storia d'Italia, per filo e per segno". La mostra ...
Tue, 12 Jan 2010 11:32:44 -0800

This blog will discuss some uses of the E.164 plus (+) character that Cisco began to fully support in Cisco Unified Communications Manager (CUCM) 7.0. The + character appears on many GSM phones sold internationally, but cannot be dialed from a ...
Il Tirreno
Fri, 21 Nov 2014 22:00:00 -0800

CASALGUIDI. Nove posti di lavoro a rischio licenziamento per i dipendenti della Gibus spa di Casalguidi, azienda leader nella produzione di tende da sole con 4 stabilimenti in Italia e 164 dipendenti totali. Dai sindacati, Fillea Cgil, Filca Cisl e ...
Sat, 22 Nov 2014 16:00:00 -0800

Bairro de Vitória em que mais se registra unidades em construção - eram 2.143 segundo o censo imobiliário de maio do Sindicato da Indústria da Construção Civil no Estado do Espírito Santo (Sinduscon-ES) - os moradores de Jardim Camburi estão atentos ...

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight