1. E.164 The International Public Telecommunication Numbering Plan Scope and Structure
Abdelfattah ABUQAYYAS
CoE/ARB Coordinator
ITU - BDT
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

2. ITU and E.164 What is the ITU? What is E.164?
Iinternational organization where governments and private sector coordinate global telecom networks and services
Founded in 1865, it is the oldest specialized agency of the UN system
189 Member States, 650 Sector Members, 75 Sector Associates
Website:
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 ITU-T TSB Director)
Defines number structure and functionality for principal categories of numbers
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

3. E.164: The international public telecommunication numbering plan
Recommendation E.164 provides the number structure and functionality for the three categories of numbers used for international public telecommunication.
All telephone numbers can be called if a number is dialled of upto 15 digits, made up of a one to three digit country code (CC), followed by the subscriber number (SN).
The first few digits of the subscriber number can be a so called National Destination Code (NDC), which can identify the type of telephone number you're calling.
All country codes are assigned by ITU in Recommendation E.164
Within Recommendation E.164 four categories of telephone numbers are recognized, namely for:
National (Geographical areas) telephone services
Global telephone services
International networks
Group of countries
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

4. E.164 Scope
E.164 provides the number structure and functionality for the following three categories of International Public Telecommunication numbers (E.164 numbers).
Geographical Global Networks
areas services
In addition to these three categories the following two new categories
will hopefully appear in a revised E.164.
Groups of Trials
countries
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

5. Examples of E.164 Resources
Geographic areas
ITU Member States, including integrated numbering plan involving more than one (e.g. +1)
Global Services
Universal International Freephone Numbers (+800)
Universal Personal Telecommunications ( digit IC)
Networks
Global Mobile Systems ( digit IC)
Shared code for Networks ( digit IC)
Groups of Countries
ETNS
For each of the categories, it details the components of the numbering structure and the digit analysis required to successfully route the calls
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

6. Structures and options National telephone services
An international public telecommunication number (for geographic areas) is also referred to as the national significant number (NSN), which consists of the country code CC, national destination code NDC and the subscriber number SN. The country code consists of one to three digits and the national destination code is optional Number structure for geographical areas CC
NDC SN CC
NDC + SN
CC: country code (1 – 3 digits)
NDC: national destination code
SN: subscriber number
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

7. Structures and options
Numbers for geographical areas, formats
for national use.
Option 1: separated NDC and SN
NDC SN CC SN
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

8. Structures and options
Numbers for geographical areas, formats
for national use.
Option 1: separated NDC and SN CC
NDC SN
NDC SN SN
National prefix
International prefix
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

9. Structures and options
Numbers for geographical areas, formats
for national use.
Option 2: connected NDC and SN CC
NDC SN
NDC SN
National subscriber number
The leading digits of the national subscriber
numbers indicates services and/or geography.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

10. Structures and options
Numbers for geographical areas, formats
for national use.
Option 2: connected NDC and SN CC
NDC SN
International prefix
NDC SN
When NDC and SN are inseparably connected
to form a single dialling sequence, a national
prefix is not necessary.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

11. Structures and options
Numbers for geographical areas, formats
for national use.
Option 1 and 2 are normally used in parallel,
with option 1 for geographic numbers and
option 2 for national location independent
numbers.
Option 2 can however be used for both type
of numbers nationally.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

12. Structures and options Global telephone services
An international public telecommunication number for global telephone services consists of a three digit country code and global subscriber number. The country code is always in the the 8xx or 9xx range
Numbers for Global Services CC
GSN
Country code
(3 digits)
Global significant number (Max 12 Digits)
Global significant number
The leading digits of GSN may indicate some service specific characterics.
The global services have only one international format, but access to global services
CC: Country Code for global service (800, 808, 878, 979)
GSN: Global Significant Number
SN: subscriber number
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

13. Structures and options Numbers for Networks
Network is inter- nationallly interconnected physical nodes and operational systems operated and maintained by one or more ROAs to provide public Telecommunication service
CC1
CC2
CC3
CC4
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

14. Structures and options International networks
An international public telecommunication number for international networks consists of three digit country code, a network identification code and a subscriber number. The country code is always in the 8xx range. The identification code is one to four digits. Numbers for Networks CC SN IC CC
IC + SN
CC: Country Code for Networks (882) - 3 digits
IC: Identification Code - 1 to 4 digits
SN: Subscriber Number - Max 15-n (number of digits in CC+IC) digits
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

15. Structures and options
Numbers for Networks, optional formats CC IC SN
Incoming to Network
Between Networks
Network internal
To use the three formats for the mentioned
purposes each Network would have to create
their own Network internal prefixes.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

16. Structures and options Numbers for Groups of countriesCC
GIC SN
3 digits
1 digit
Max 11 digits
CC: Country Code for Groups of countries (tbd)
GIC: Group Identification Code
SN: Subscriber Number
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

17. Structures and options Numbers for TrialsCC
TIC SN
3 digits
3 digits
Max 9 digits
CC: Country Code for Trials (991)
TIC: Trial Identification Code
SN: Subscriber Number
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

18. Numbering for geographic areas
Prefixes are not part of the E.164 number
and are not signalled over international
boundaries.
E.164 indicates preference for the use of digit
0 as national prefix.
The digit analysis should not be more than 7
digits to determine the country of destination,
the most appropriate routeing and the proper
charging.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

19. Planning advices for geographic areas
The national numbering plans should be designed:
a) to allow for generous provision of future growth;
b) so that the national networks be accessible to subscribers in other countries by means of international dialling procedures.
c) so that subscribers would always be called by the same national number regardless of where the call is originated from within a national numbering plan.
It is recommended that notification of national
numbering changes be submitted at least 2 years in
advance.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

20. International prefix E.164 recommends that Administrations
that are revising their numbering plans
adopt 00 as an international prefix.
CC1
CC2
CC3
CC4
00 + E.164 numbers
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

21. Frequently asked question
When is a number an E.164 number?
When it satisfies the following:
1. It has to be part of an ITU defined fixed international hierarchical structure.
2. It has to be maximum 15 digits.
3. It has to be unique in its international format.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

22. Case Study - Singapore
The National Numbering Plan provides a set of rules and guidelines for assigning numbers to Public Switched Telephone Network (PSTN) and Radio Network.
The Plan also describes the assignment of numbers to international, trunk, emergency and special services such as voice mail, Intelligent Network (IN) services.
Under the plan, numbers are categorized in various services under the National Numbering Plan according to the first digit.
The structure of the national number generally complies with the relevant (ITU-T) Recommendations.
IDA, as the regulator for telecommunications, controls and manages the National Numbering Plan to ensure that the number allocation process is fair and transparent.
IDA has to strike a balance in ensuring that the limited number resources are used efficiently and optimally and yet do not impose undue operational constraints on the telecommunication service providers.
The National Numbering Plan will be reviewed from time to time to ensure its continued relevance in light of technological advances and the introduction of new services
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

23. Case Study – Singapore Numbers with Leading Digit 0 and 1
Numbers beginning with the digit ‘0’ are reserved for international services such as prefixes for International Direct Dial (IDD) service, Subscriber Trunk Dial (STD). The length of these prefixes is standardized at three digits. They are referred to as Level ‘0’ short codes.
Facility Based Operators (FBO) licensees are eligible for 3-digit access codes provided that they commit an overall investment in infrastructure of an amount not less than S$150 millions over the first 3 years from date of licensing. FBO licensees must use the access codes to provide service for the mass consumer market.
Numbers with Leading Digit 1
Numbers beginning with the digit ‘1’ are reserved for special services which includes calls for operator assistance, service enquiry, voice information, IN services and access code IDD type of services. Their length generally ranges from four to five digits. They are referred to as Level ‘1’ short codes.
Only FBO licensees are eligible for level ‘1’ short codes. However, for Service-based Operator (SBO) licensees who propose to operate an International Simple Resale (ISR) service. they will be also be allocated from ‘15XX’ level.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

24. Case Study – Singapore Numbers with Leading Digit 6 and 9
Numbers beginning with the digits ‘6’ are reserved for use as ordinary PSTN numbers. The length of these numbers is standardized at eight digits.
A FBO licensee offering domestic telephony services are eligible for PSTN numbers.
Numbers with Leading Digit 9
Numbers beginning with the digit ‘9’ are reserved for three digit emergency services and eight digit Radio Network numbers.
FBO licensees offering Radio Network services including Public Cellular Mobile Telephone Services, Public Radio Paging Services and Public Trunked Radio Services are eligible for Radio Network numbers.
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004

25. E.164 The International Public Telecommunication Numbering Plan Scope and Structure
THANK YOU
ITU – BDT
Workshop on Numbering Plan Policies
Sana’a – Yemen, 13 – 15 September 2004