A TECHNICAL PRESENTATION

ON

Mr. Nimay Giri, M-Tech

TELEPHONE NUMBERING PLANS

By

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

OBJECTIVE A telephone numbering plan is a type of numbering scheme

used in telecommunication to assign telephone numbers tosubscriber telephones or other telephony endpoints.

… by Wikipedia

o The objective of numbering plan is to uniquely identify everysubscriber 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

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.

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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.

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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 byalmost one or two digits.

Open Numbering Plan: Different dialing arrangement for local area andlong distance . variation in digits/numbers occurs i.e. Non-uniform type.

Semi Closed Numbering Plan: Numbering lengths to differ by almost oneor two digits.

Closed Numbering Plan: Subscriber’s number is used same for all callstypes of NUMBERING PLAN. (i.e. number of digits in a subscriber numberis not changed). It is also known as Uniform numbering scheme.

INDIA uses: semi-open & semi-closed type numbering plan.

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CONT… A broad division is commonly recognized,

distinguishing open numbering plans and closednumbering plans.

A closed numbering plan imposes a fixed number ofdigits to every telephone number, where the caller mustalways dial the full national significant number (NSN)when placing a call.

An open numbering plan may allow local calls to bedialed without the area code or allow variance in thenumbers of digits.

Nimay Giri, M-Tech

TELEPHONE NUMBERING PLANS

The numbering plan in telecom sectors for acountry is an important ‘fundamental plan’ thatrequires careful and judicious reviews to constantlymeet the country’s requirements as thetelecommunications network grows and newdevelopmental challenges surface.

International Numbering Plans

National Numbering Plans

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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

WORLD ZONE AS PER ITU-T

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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;

FORMAT FOR INTERNATIONAL

NUMBERING PLAN Every International number consists of three main parts.

ITU Template for number plans:-

|………………………...15 digits (max)……………………………|

|---------National Number (9-12digits)------------|

(Rule of CCITT)

o The International Telecommunication Union (ITU) has established acomprehensive numbering plan, designated E.164, for uniform interoperabilityof the networks of its member state or regional administrations.

o It is an open numbering plan, however, imposing a maximum length of 15digits to telephone numbers.

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Country code (CC) Area Code (AC) Directory/Subscriber Number

1-3/4 1-3 Central Office Code Destination Number

1-3 1-4

CONT…

The country calling code: is a prefix number, not exceeding 3digits, which identifies a specific country or group ofcountries.

• Country code depends on the world zone in which countrypresent.

The area code: is a variable number, for particular country, stateor 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, whichidentifies a particular subscriber or telephone line number.

• The area & central office number depends on the nationalzone in which state, district, area present.

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NATIONAL NUMBERING PLAN

The National Numbering Plan (NNP) provides a set of rulesand guidelines for the use and assignment of numbers totelephone services delivered over the Public Networks.

This is defined for only national level numbering (Ex. India).

The Plan also describes the assignment of numbers tointernational services, trunk service, emergency services andspecial services such as voice mail and IN services.

The National Numbering Plan is one of the Fundamental Plansalong with Switching, Routing, Transmission, Charging andSynchronization Plans. … by ITU-T

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ZONE DIVIDED IN INDIA As per the world region, country also divided into

different region with region code/number.

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FORMAT FOR NATIONAL NUMBERING

PLAN Every national number that contain different three part of the telephone number.

|------------ Subscriber Number--------------|

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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.

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.

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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.

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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 thesame as +91-7381730901 and 91-7381730901.

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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 frombasic services to cellular mobile.

Prefix code.

Format: “00”+ CC+ Operator number

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CONT…

LEVEL-1

Accessing special services like emergency services, supplementaryservices, inquiry and operator-assisted services.

Maximum length up to 3 digits.

Ex. 100 for police, 101 for fire, 102 for ambulance and 108for emergency disaster management.

Used for providing the services within their network.

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CONT…

LEVEL-2 TO 6

Reserved for PSTN/ISDN within Short Distance ChargingArea (SDCA).

In SDCAs vary between 5 to 7 digits.

The total Number is 9-digit, except in a few cases where itis already 10-digit uniform and of 10-digit length.

It is Uniform to type of system.

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CONT…

LEVEL 7-8

Reserved for new services.

LEVEL 9

Reserved for cellular mobile services. Thesewill be allocated in 2-digit format.

Ex. “90”, “94” “81”, “71”…

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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

CONCLUSION

Numbering plan used for identify the uniquesubscriber by using it’s unique number DOT(Department of Telecommunication)controlling all the telecommunication ortelegraph based rules & controlling in INDIA.

Consultative Committee for InternationalTelephony and Telegraphy (CCITT) or ITU-Tcontrolling all the telecommunication ortelegraph based rules & controlling inWORLD Zone.

Nimay Giri, M-Tech