Basics of Networks ,Advantages and Disadvantages

Types of networks,Network Terms

1. COMPUTER NETWORKS
Prepared by
S.Sabari Giri Murugan
Faculty G2-Grade
KL University
SESSION I
Basics of Network & Networking, Advantages of Networking,
Types of Networks, Network Terms- Host, Workstations,
Server, Client, Node

2. BASICS OF NETWORK &
NETWORKING
What is Data?
What is Communication?

3. 3
COMPONENTS IN
COMMUNICATION
Hi, how are you?
5Protocol
4Medium
3Receiver
2Sender
1Message

4. DATA COMMUNICATION:
DEFINITION
Data Communication has two types :
1.Local -Local communication takes place when the
communicating devices are in the same
geographical area, same building, face-to-face
between individuals etc
2.Remote-Remote communication takes place over
a distance i.e. the devices are further 4Transfer of data from one device to another via
some form of transmission medium.
Transfer of data from one device to another via
some form of transmission medium.

5. EFFECTIVENESS OF A DATA
COMMUNICATION CAN BE MEASURED
THROUGH THE FOLLOWING FEATURES
Delivery : Delivery should be done to the correct
destination.
Timeliness : Delivery should be on time.
Accuracy : Data delivered should be accurate.
Jitter : Variation in packet arrival.

6. DATA REPRESENTATION
Numbers
8/16/32 bit integers
floating point
Text
ASCII, Unicode
Images
Bit patterns, Graphics formats JPG/GIF/etc
Audio ® Samples of continuous signal
Video ® Sequence of bitmap images
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7. PROTOCOLS
Protocol
A set of rules governing data communications
Syntax
Structure or format of the data
Semantics
Interprets the meaning of the bits
Knows which fields define what action
Timing
When data should be sent and what
Speed at which data should be sent or speed at which it is
being received.
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8. DIRECTION OF DATA FLOW
Simplex: One direction only
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Server Monitor
data flow
Keyboard
data flow

9. DIRECTION OF DATA FLOW
Half Duplex: Both directions, one at a
time
E.g., walkie-talkies
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data flow at time 1
data flow at time 2

10. DIRECTION OF DATA FLOW
Full Duplex: Both directions simultaneously
E.g., telephone
Can be emulated on a single communication
link using various methods
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data flow
data flow

11. DIFFERENCE B/W
TELECOMMUNICATION & DATA
COMMUNICATION?

12. NETWORK
Topics discussed in this section:Topics discussed in this section:
Définitions
Network Criteria
Physical Structures
Categories of Networks

13. NETWORK DEFINITION
A A networknetwork is a set of devices (often referred to as is a set of devices (often referred to as nodesnodes) )
connected by communication connected by communication linkslinks. .
A node can be a computer, printer, or any other device A node can be a computer, printer, or any other device
capable of sending and/or receiving data generated by capable of sending and/or receiving data generated by
other nodes on the network. other nodes on the network.
A link can be a cable, air, optical fiber, or any medium A link can be a cable, air, optical fiber, or any medium
which can transport a signal carrying information.which can transport a signal carrying information.

14. PURPOSE
The purpose of a network is to share resources.
A resource may be:
A file
A folder
A printer
A disk drive
Or just about anything else that exists on a
computer.

15. NETWORK CRITERIA
A network must be able to meet certain criteria, these are mentioned below:
Performance
Reliability
Scalability
Performance :
It can be measured in following ways :
Transit time : It is the time taken to travel a message from one device to
another.
Response time : It is defined as the time elapsed between enquiry and
response.
Other ways to measure performance are :
Efficiency of software
Number of users
Capability of connected hardware

16. CONTD..
Reliability
It decides the frequency at which network failure
take place. More the failures are, less is the
network's reliability.
Security
It refers to the protection of data from the
unauthorized user or access. While travelling
through network, data passes many layers of
network, and data can be traced if attempted. Hence
security is also a very important characteristic for
Networks.

17. PROPERTIES OF GOOD NETWORK
Interpersonal Communication :  We can
communicate with each other efficiently and
easily example emails, chat rooms, video
conferencing etc.
Resources can be shared :  We can use the
resources provided by network such as printers
etc.
Sharing files, data : Authorized users are
allowed to share the files on the network.

18. TYPES OF CONNECTIONS
Point-to-point-Dedicated link
Multipoint (Timeshared)-Shares a single link
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19. POINT-TO-POINT CONNECTION
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20. MULTIPOINT CONNECTION
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Wireless

21. ADVANTAGES OF NETWORKING
Connectivity and Communication
Data Sharing
Hardware Sharing
Internet Access
Internet Access Sharing
Data Security and Management
Entertainment

22. THE DISADVANTAGES (COSTS) OF
NETWORKING
Network Hardware, Software and
Setup Costs
Hardware and Software Management
and Administration Costs
Undesirable Sharing
Illegal or Undesirable Behavior
Data Security Concerns

23. NETWORK CATEGORIES
Local Area Network (LAN)
Wide Area Network (WAN)
Metropolitan Area Network (MAN)
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24. LOCAL AREA NETWORKS
A local area network (LAN) is a computer
network covering a small geographic area, like a
home, office, or group of buildings
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25. WIDE AREA NETWORKS
Network providing long-distance
communication over a country, a
continent, or the whole world
Two or more LANs connected together
The Internet is an example
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26. METROPOLITAN AREA NETWORKS
Network extended over an entire city
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Bangkhen Kampangsaen

27. NETWORK TERMS- HOST,
WORKSTATIONS, SERVER, CLIENT,
NODE
Host:
A network host is a computer or other device
connected to a computer network. A network host
may offer information resources, services, and
applications to users or other nodes on the network. A
network host is a network node that is assigned
a network layer host address
Workstations:
A workstation is a special computer designed for
technical or scientific applications. Intended primarily
to be used by one person at a time, they are commonly
connected to a local area network and run multi-user
operating systems.

28. CONTD..
Server :
computer is a core component of the network,
providing a link to the resources necessary to perform
any task.
Client :
computers normally request and receive
information over the network client. Client computers
also depends primarily on the central server for
processing activities