IT will give idea of both national & international numbering plan system.

1. A TECHNICAL PRESENTATION
ON
Mr. Nimay Giri, M-Tech
TELEPHONE NUMBERING PLANS
By

2. TOPIC CONTENT
 Objective
 Introduction
 History
 Types of numbering plans
 World zones
 History of country code
 Format of international & national numbering plan
 Zone divided in INDIA
 Telephone numbering in INDIA
 Dial plan
 Types of levels
 Telecom company operators in INDIA
 Conclusion
Nimay Giri, M-Tech

3. OBJECTIVE
 A telephone numbering plan is a type of numbering scheme
used in telecommunication to assign telephone numbers to
subscriber telephones or other telephony endpoints.
… by Wikipedia
o The objective of numbering plan is to uniquely identify every
subscriber connected to a telecommunication network.
o A number can be determined either national or international.
- supporting subscriber telephone numbers
- regulating the allocation of numbers
- coping with the modern technological developments of
telecommunication networks
- expanding the national and international services
- preparing the market for any new entrants
Nimay Giri, M-Tech

4. INTRODUCTION
 Numbering plan is used to identify the subscribers connected in
a telecommunication system by ITU-T.
 It allows “subscriber” to make and receive calls across long
distance.
 Necessary to have numbering plan to define “particular
subscriber”.
 Numbering plan help us to find the “particular subscriber”.
 It is a decimal digits contain necessary information to rout the
call.
Nimay Giri, M-Tech

5. HISTORY
 In early telephone systems, connections were made in the central office
by switchboard operators using patch cords to connect one party to
another.
 Rotary dials phone took to dial the area code for pulse-dialing and then
Touch-Tone key pads in the 1960s.
 Area codes concept used in 1947, US and Canada.
 North American Numbering Plan developed 10 digits no. for dialing.
 In the early days, exchanges were identified by the names of the towns
in which they were located.
 As the numbers of subscriber increase, there are more than one
exchange available in one town.
 Now requirement of multi-exchange area for every nation.
Nimay Giri, M-Tech

6. TYPES OF NUMBERING PLANS
 A numbering plan may be Semi-open or Open or may be Semi-closed or
Closed type.
 Semi Open Numbering Plan: permits number lengths to be different by
almost one or two digits.
 Open Numbering Plan: Different dialing arrangement for local area and
long distance . variation in digits/numbers occurs i.e. Non-uniform type.
 Semi Closed Numbering Plan: Numbering lengths to differ by almost one
or two digits.
 Closed Numbering Plan: Subscriber’s number is used same for all calls
types of NUMBERING PLAN. (i.e. number of digits in a subscriber number
is not changed). It is also known as Uniform numbering scheme.
 INDIA uses: semi-open & semi-closed type numbering plan.
Nimay Giri, M-Tech

7. CONT…
 A broad division is commonly recognized,
distinguishing open numbering plans and closed
numbering plans.
 A closed numbering plan imposes a fixed number of
digits to every telephone number, where the caller must
always dial the full national significant number (NSN)
when placing a call.
 An open numbering plan may allow local calls to be
dialed without the area code or allow variance in the
numbers of digits.
Nimay Giri, M-Tech

8. TELEPHONE NUMBERING PLANS
 The numbering plan in telecom sectors for a
country is an important ‘fundamental plan’ that
requires careful and judicious reviews to constantly
meet the country’s requirements as the
telecommunications network grows and new
developmental challenges surface.
 International Numbering Plans
 National Numbering Plans
Nimay Giri, M-Tech

9. INTERNATIONAL NUMBERING PLANS
 International Numbering Plans (INP) is specialized in world-wide
(tele)communications related numbering plans in globally.
 An international numbering plan or world numbering plan has been
explained by Committee for International Telephony and Telegraphy
(CCITT) in recommendations of this E.160-E.163.
 CCITT was created in 1956 & renamed ITU-T in 1993, designated E.164
for comprehensive numbering plan.
 For international numbering plan world divided into nine (9) regions.
 Maximum 12-15 digits for telephone numbers, including country calling
code, area codes & subscribers number or destination number.
 The ITU-T recommends the sequence “00” as a standard for international
call prefix, implemented by many country (Ex. US, India…) but not all of
them (Ex. “o” used by Samua , “000” used by Uganda & “001” used by
Hong Kong) Nimay Giri, M-Tech

10. WORLD ZONE AS PER ITU-T
Nimay Giri, M-Tech
This is a list of country calling codes or dial in code defined by ITU-
T recommendations E.123 and E.164, also called IDD (International Direct
Dialling) or ISD (International Subscriber Dialling) codes.
• ITU-T Divided total World in to 9-Zones (BOOK) as bellows Figure;

11. FORMAT FOR INTERNATIONAL
NUMBERING PLAN Every International number consists of three main parts.
ITU Template for number plans:-
|………………………...15 digits
(max)……………………………|
|---------National Number (9-12
digits)------------|
(Rule of CCITT)
o The International Telecommunication Union (ITU) has established a
comprehensive numbering plan, designated E.164, for uniform interoperability
of the networks of its member state or regional administrations.
o It is an open numbering plan, however, imposing a maximum length of 15
digits to telephone numbers.
Nimay Giri, M-Tech
Country code (CC) Area Code (AC) Directory/Subscriber Number
1-3/4 1-3 Central Office Code Destination Number
1-3 1-4

12. CONT…
The country calling code: is a prefix number, not exceeding 3
digits, which identifies a specific country or group of
countries.
• Country code depends on the world zone in which country
present.
The area code: is a variable number, for particular country, state
or province, also known as number plan area (NPA).
The Central Office Code: is a number, not exceeding 3 digits,
identifies a particular district within an area in a country.
The destination number: is a 4 digits suffix number, which
identifies a particular subscriber or telephone line number.
• The area & central office number depends on the national
zone in which state, district, area present.
Nimay Giri, M-Tech

13. NATIONAL NUMBERING PLAN
 The National Numbering Plan (NNP) provides a set of rules
and guidelines for the use and assignment of numbers to
telephone services delivered over the Public Networks.
 This is defined for only national level numbering (Ex. India).
 The Plan also describes the assignment of numbers to
international services, trunk service, emergency services and
special services such as voice mail and IN services.
 The National Numbering Plan is one of the Fundamental Plans
along with Switching, Routing, Transmission, Charging and
Synchronization Plans. … by ITU-T
Nimay Giri, M-Tech

14. ZONE DIVIDED IN INDIA
 As per the world region, country also divided into
different region with region code/number.
Nimay Giri, M-Tech

15. FORMAT FOR NATIONAL NUMBERING
PLAN
 Every national number that contain different three part of the telephone number.
|------------ Subscriber Number--------------|
Nimay Giri, M-Tech
Area/Trunk Code Exchange code Line Number
1-3 digits 1-3 digits 2-4/5 digits
 National numbering system can be divided in to area code,
Exchange code & line number.

16. CONT…
 Area code: can be defined by using the region geographically in which
that area come. Its variable number for a particular country.
 It also known as Numbering Plan Area (NPA) codes in US. In the UK,
they were known as subscriber trunk dialing (STD) codes.
 Exchange code: its length up to 3 digits identifies the Exchange office
within the area code, which are unique to each telephone
exchange within an NPA. The remaining four digits are the specific
station number assigned to each telephone.
 Line Number: The subscriber number is the number assigned to a line
connected to one customer's equipment.
 The first few digits of the subscriber number typically indicate smaller
geographical areas or individual telephone exchanges. In mobile
networks they may indicate the network provider.
Nimay Giri, M-Tech

17. MOBILE STATION INTERNATIONAL
SUBSCRIBER DIRECTORY NUMBER
(MSISDN) MSISDN is a number uniquely identifying a subscription in a GSM or
a UMTS mobile network. Simply put, it is the telephone number to
the SIM card in a mobile/cellular phone.
 MSISDN is primary key to the HLR record number with maximum
15 digits without prefixes.
 The MSISDN together with IMSI are two important numbers used for
identifying a mobile subscriber.
 The latter is stored in the SIM, i.e. the card inserted into the mobile
phone, and each IMSI uniquely identifies the mobile station, its home
wireless network.
 For national Ex. +91-7381303900 and for international the same
number will be “00”+ CC+7381303900.
Nimay Giri, M-Tech

18. CONT…
 Ex-1: one number in America
 MSISDN: 13109976224 or +13109976224
CC: 1 United States of America - Country Code
NDC: 310 California - National destination code
SN: 9976224 Sasa Divac - Customer or subscriber code
NDC: National Destination Code , for California in this example is 310.
SN: subscriber number.
o Ex-2: one number in India
o MSISDN: +91-7381730900 (Odisha)
CC: +91 INDIA-Country code
NDC: 7381 Odisha- National destination code
SN: 730900 prakash Das- Customer or subscriber code/subscriber number.
o A mobile number in the INDIA (national) would be 07381730901 this is the
same as +91-7381730901 and 91-7381730901.
Nimay Giri, M-Tech

19. TYPES OF LEVELS (NATIONAL)
LEVEL-0
 National long distance calls.
 Intra service area long distance calls of basic services.
 Cellular mobile to basic services calls and calls from
basic services to cellular mobile.
 Prefix code.
 Format: “00”+ CC+ Operator number
Nimay Giri, M-Tech

20. CONT…
LEVEL-1
 Accessing special services like emergency services, supplementary
services, inquiry and operator-assisted services.
 Maximum length up to 3 digits.
 Ex. 100 for police, 101 for fire, 102 for ambulance and 108
for emergency disaster management.
 Used for providing the services within their network.
Nimay Giri, M-Tech

21. CONT…
LEVEL-2 TO 6
 Reserved for PSTN/ISDN within Short Distance Charging
Area (SDCA).
 In SDCAs vary between 5 to 7 digits.
 The total Number is 9-digit, except in a few cases where it
is already 10-digit uniform and of 10-digit length.
 It is Uniform to type of system.
Nimay Giri, M-Tech

22. CONT…
LEVEL 7-8
 Reserved for new services.
LEVEL 9
 Reserved for cellular mobile services. These
will be allocated in 2-digit format.
 Ex. “90”, “94” “81”, “71”…
Nimay Giri, M-Tech

23. POSSIBLE APPROACHES FOR DIALING
 SINGLE uniform procedure for all calls.
 TWO different procedure, one for international
calls & other for national calls.
 THREE different procedure, one for international
calls, second for national trunk calls & other for
local calls.
 FOUR different procedure, one for i international
calls, second for national trunk calls, third for local
calls & other for calls in the adjacent numbering
areas.
Nimay Giri, M-Tech

24. CONCLUSION
 Numbering plan used for identify the unique
subscriber by using it’s unique number DOT
(Department of Telecommunication)
controlling all the telecommunication or
telegraph based rules & controlling in INDIA.
 Consultative Committee for International
Telephony and Telegraphy (CCITT) or ITU-T
controlling all the telecommunication or
telegraph based rules & controlling in
WORLD Zone.
Nimay Giri, M-Tech