The document introduces computer networks and their types, including LAN, CAN, MAN and WAN. It describes client/server configuration and the 7-layer OSI model. It also covers network selection criteria and standards organizations that develop network standards. Case studies provide examples of using different network types in business scenarios.

1. Introduction to
Computer Networks
Chapter 1
Chapter 1 1

2. Chapter Objectives
 Explain the need of networks
 Explain history of computer networks (ARPANET)
 Explain the types of computer networks
 Explain Client/Server configuration
 Explain layers of OSI model
 Explain network selection criteria
 Application
 Explain Standards Organizations
Chapter 1 2

3. Computer Network
 Interconnection of two or more computers and
peripherals
 Allows user to share and transfer information
Chapter 1 3

4. Types of Computer Networks
 Networks are classified depending on the
geographical area covered by the network
Computer
Networks
Local Campus Metropolitan Wide
Area Network Area Network Area Network Area Network
(LAN) (CAN) (MAN) (WAN)
Chapter 1 4

5. Local Area Network (LAN) - I
 Covers a small area
 Connects computers and workstations covering a
local area like, office or home
Chapter 1 5

6. Local Area Network (LAN) - II
 Advantages of LAN:
 Improves productivity due to faster work
 Provides easy maintenance
 New systems can be installed and configured
easily
 Disadvantages of LAN:
 Limited number of systems can only be connected
 Cannot cover large area
 Network performance degrades as number of
users exceeds
Chapter 1 6

7. Types of LAN
 LANs are classified depending on the techniques
used for data sharing
LAN Types
Ethernet Token Ring Token Bus FDDI
Chapter 1 7

8. Campus Area Network (CAN)
 Made up of multiple LANs within limited area
 Connects different LANs in a campus
Chapter 1 8

9. Metropolitan Area Network
 Interconnects networks within a city
 Supports data and voice transmission
Chapter 1 9

10. Wide Area Network
 Covers a wide geographical area which includes
multiple computers or LANs e.g. Internet
Chapter 1 10

11. Case Study - I
MoneyMaker is a bank having its registered office at
Delhi. It has branches at Mumbai, Chennai,
Hyderabad and Bangalore. The operating departments
in the bank are Finance, Insurance, Loan, IT,
Marketing, Customer Service and HR. MoneyMaker
bank uses LAN as their computer network for each
department. All the branches of the bank from different
cities are connected through WAN. The bank is
expanding and decided to open its branches at
different locations in the city.
Chapter 1 11

12. Problem
Determine which type of network to be used within a
city
Chapter 1 12

13. Suggested Solution
Use LAN computer network for each department in the
new branch. MAN can be used for connecting the
different branches of the bank within the city
Chapter 1 13

14. Client/Server Configuration
 Consists of two elements, Client and Server
 Server:
 A centralized element which provides resources
to client
 Manages data, printers or network traffic
 Client:
 Manages local resources used by users such as
monitor, keyboard, CPU and peripherals
Chapter 1 14

15. Open System Interconnection (OSI)
Model - I
 Also known as ISO-OSI Reference Model
 Developed by International Organization for
Standardization (ISO)
 Describes flow of information from one computer to
another
 Consists of seven layers
Chapter 1 15

16. Open System Interconnection (OSI)
Model - II
Chapter 1 16

17. Network Selection Criteria
 Helps to improve network functionality
Network
Criteria
Performance Reliability Security
Chapter 1 17

18. Case Study - II
The Customer Service department of MoneyMaker
bank provides online services to the customers. At
Hyderabad branch, the Customer Service department
network is not functioning properly. So the bank has
decided to build an alternative network for that
department .
Chapter 1 18

19. Problem
Selecting the network criteria
Chapter 1 19

20. Suggested Solution
Decide network type and configuration, number of
users, speed of the network, hardware to be used,
operating system to be installed and anti-virus
software
Chapter 1 20

21. Standards Organizations
 Also known as Standards Development
Organization (SDO)
 Develop, maintain, improve and revise standards
 Classified as:
 International organozations – International
Organization for Standardization (ISO)
 National organozations – American National
Standards Institute (ANSI)
 Regional organozations – Euro-Asian Council for
Standardization (EASC)
Chapter 1 21

22. Summary - I
 Computer network enables the user to share data
and network resources
 Network allows remote users to communicate with
each other
 Computer networks are divided into LAN, CAN,
MAN and WAN depending on the coverage area
 LAN is a small network and easy to create
 Client/Server configuration also called as two-tier
architecture, consist of two nodes, client and server
Chapter 1 22

23. Summary – II
 OSI model consists of seven layers and provides
standards for computer communication
 Physical layer is responsible for actual transmission
of bits over the medium
 Data Link layer is responsible for node to node
delivery of frames
 Network layer is responsible for end to end delivery
of packets, and routing
Chapter 1 23

24. Summary - III
 Transport layer is responsible for end to end
delivery of the entire message
 Session layer is responsible for establishing,
managing and terminating sessions
 Presentation layer is responsible for translation,
encryption and data compression
 Application layer is responsible for providing access
to the network
Chapter 1 24

25. Summary - IV
 Performance, reliability and security are the network
selection criterion which enables to choose efficient
network
 Standards organizations like ISO and ANSI develop
technical and non- technical standards
 International standards organizations are
International Standard Organization (ISO),
International Telecommunication Union (ITU),
Institute of Electrical and Electronics Engineers
(IEEE) and World Wide Web Consortium (W3C)
Chapter 1 25