The document provides an overview of Integrated Services Digital Network (ISDN), explaining its purpose to digitize telephone networks for transmitting audio, video, images, and text. It details the types of ISDN, including Narrowband and Broadband ISDN, along with their data rates and functionalities. The objectives of ISDN include standardization, transparency, and flexible service options, which benefit users by providing cost savings, flexibility, and integrated voice and data services.

1. Introduction to Data communication
Topic: Integrated Services Digital Network
(ISDN)
Lecture # 9
Dr Rajiv Srivastava
Director
Sagar Institute of Research & Technology (SIRT)
Sagar Group of Institutions, Bhopal
http://www.sirtbhopal.ac.in

2. Unit 2
Lecture 9
Course Lecture 26
Integrated Services Digital
Network
(ISDN)

3. A Quick Glance To History of
Transmission

4. Voice Communication Over An
Analog Telephone Network

5. Voice and Data Communication
over an Analog Telephone Network

6. Analog and Digital Services
over the Telephone Network

7. Integrated Digital Network (IDN)

8. ISDN
Digital Pipes : TDM channels with very high
transmission speed with one or two pairs of
copper wires
ISDN incorporates all communication connections in a
home or building into a single interface

9. • Integrated Services Digital Network(ISDN) was
developed by ITU-T in 1976
• The purpose of the ISDN is to provide fully integrated
digital services to the users
• It is a set of protocols that combines digital telephony
& data transfer/transport services
• The whole idea is to digitize the telephone network to
permit the transmission of audio, video, images &
text over existing telephone lines
ISDN

10. • It is an effort to standardize subscriber services
& provide usage of internet services over it
• The Goal of ISDN is to form a wide area
network that provides universal end-to-end
connectivity over digital media
• And, this can be done by integrating all of the
separate transmission services into one without
adding new links or subscriber lines.

11. Definition of ISDN
An integrated Service Digital Network
(ISDN) is a communication technology that
combines digital telephony & data
transport services. The idea is to digitize
the telephone network to allow the
transmission of audio(like voice etc), video,
images & text over existing telephone
lines.

12. Types of ISDN
• Narrowband ISDN
– uses data transmission speed upto 64 kbps using
circuit switching technology
– Narrowband ISDN provides 144kbps and 2.048Mbps
data rates.
• Broadband ISDN (B-ISDN)
– It supports very high data rate (in range of 100 mbps)
– It uses packet switching orientation
– It uses 2B/1Q digital coding
– It uses Asynchronous Transfer Mode (ATM) technology
– Broadband ISDN provides 155.52Mbps and 622.08Mbps
data rates.

13. • Given figure is a conceptual view of the ISDN from a user
or customer point of view.
• User has access to ISDN via a local interface to a digital
pipe.
• Pipes of various sizes are available to satisfy different
needs. Each pipe may contain 1 or two twisted pair of wires.
• Pipe to the user’s premises has a fixed capacity but the
traffic on the pipe may be a variable mix up to the capacity
limit.
• ISDN requires control signals to instruct how to sort out the
time multiplexed data and provide the required services.
ISDN User Interface

14. • Control signals are multiplexed onto the same
digital pipe.
• A user may employ less than the maximum
capacity of the pipe and will be charged
according to the capacity used.
• Figure shows ISDN user interface example.

15. Figure : Conceptual View of ISDN Connections

16. ISDN

17. Objectives of ISDN
• The objectives of the activities for developing
a worldwide ISDN are:
•Standardization
•Transparency
•Separation of competitive functions
•Leased and switched services
•Cost related tariffs
•Smooth migration
•Multiplexed support

18. Standardization
• To provide access to the network.
• Movable ISDN-standard equipment and use of
layered protocol.
• To allow users to select equipment from multiple
suppliers.
Transparency
• Digital transmission service is independent of the
contents of data.
• Users can develop new applications and protocols.
• User provided encryption methods can be employed
simply.

19. Separation of competitive functions
• ISDN does not preclude competitive functions from basic
ones.
• Some countries desire certain enhanced services be offered
competitively (e.g. videotex, electronic mail).
Leased and switched services
• ISDN should provide both leased and switched services.
• To allow users to optimize on the basis of cost and
performance.
Cost-related tariff
• One type of service does not subsidize others.
• Price distinctions related to the cost of providing specific
performance and functional characteristics of a service.

20. Smooth migration
• ISDN evolution must coexist with existing
equipment and services specific capabilities
required: pre-ISDN terminals to interface to
ISDN inter-network protocols and protocol
converters.
Multiplexed support
• Accommodating user-owned PBX and LAN
equipment.

21. Benefits of ISDN
• The principle benefits of ISDN to the customers
can be expressed in terms of cost saving,
flexibility and speed.
• Integrated voice and data means that the user
does not have to buy multiple services to meet
multiple needs.
– Access charges are made to a single access line only.
– Purchasing services based on actual needs.
– Product diversity, low price and wide availability of
equipment.

22. ISDNOthers
Single
ISDN
terminal Multiple
ISDN
terminal
Installation
PBX
LAN,
private
network
Specialized
storage and
information
processing
centers
Figure : User Network Interface

23. Thank You
Dr Rajiv Srivastava
Director
Sagar Institute of Research & Technology (SIRT)
Sagar Group of Institutions, Bhopal
http://www.sirtbhopal.ac.in