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ITCK
Information Technology Center Of Kabul University
Networking Basics
Introducing Basic Network Concepts “In the beginning, there were no networks.
Life was bad.” —MIKE MEYERS
Mohammad Ferdous(ehsan) “safi”
Date: 21 / Sep / 2016
[email protected]
In this Lecture, you will learn :
• Networking History
• Identify Human and Computer Networks
• Describe The Benefits of Networks
(Advantages/Disadvantages)
• Computer Network Components
• Network Types (PAN,CAN,LAN,MAN,WAN,GAN)
• Networking Terminologies
Date: 21 / Sep / 2016
History of Networks :
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In the late 1950s early networks of computers included the military radar
system Semi-Automatic Ground Environments (SAGE).
In 1960 the commercial airline reservation system Semi-Automatic Business
Research Environment (SABRE) went online with two connected mainframes.
Throughout the 1960s, Leonard Kleinrock, Paul Baran, and Donald Davis
independently developed network systems that used packets to transfer
information between computers over a network.
In 1965, Thomas Marill and Lawrence G. Roberts created the first wide area
network (WAN). This was an immediate precursor to the ARPANET, of which
Roberts became program manager.
In 1969 the University of California at Los Angeles, the Stanford Research
Institute, the University of California at Santa Barbara, and the University of
Utah became connected as the beginning of the ARPANET network.
What is a Network?
Generally a Network is :
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A group or system of interconnected people or things.
Nowadays a person might make a phone call, watch a television show, listen
to the radio, look up something on the Internet, or even play a video game
with someone in country.
All of these activities depend on a network.
So network is the way to connect people no matter where they are in the
world.
What is a Human Network?
A Human Network is :
• In its broadest sense, a network consists of two or more entities,
or objects , sharing resources and information.
• Those networks are everywhere. You have grown accustomed to
working with them, possibly without even knowing it.
For example: You or Your Father, Mother, Sister, Brother.
• The humans on network may be linked by relations.
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Human Network
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What is a Computer Network?
A Computer Network is :
• A computer network or data network is a
telecommunications network which allows computers to exchange
data.
• In computer networks, networked computing devices exchange data
with each other using a data link. The connections between nodes
are established using either cable media or wireless media.
• The computers on a network may be linked through cables,
telephone lines, radio waves, satellites, or infrared light beams.
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Computer Network
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Networks are Used to :
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Facilitate communication via email, video conferencing, instant
messaging, etc.
Enable multiple users to share a single hardware device like a
printer or scanner.
Enable file sharing across the network.
Allow for the sharing of software or operating programs on
remote systems.
Make information easier to access and maintain among network
users.
Networks are Used to :
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Advantages of Network :
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Software and resources can be centrally managed.
Expensive devices such as laser printers or scanners can be shared.
Users can access their files from any workstation
Files can easily be shared between users.
Network users can communicate by email and instant messenger.
It enhances communication and availability of information.
It allows for more convenient resource sharing.
It boosts storage capacity.
Disadvantages of Network :
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It lacks independence.
It poses security difficulties.
It allows for more presence of computer viruses and malware.
Its light policing usage promotes negative acts.
The main disadvantage of networks is that users become
dependent upon them. For example, if a network file server
develops a fault, then many users may not be able to run
application programs and get access to shared data.
Different Networks
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Computer Network Components :
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Rules
Devices
Media
Services
There are many types of networks, including:
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
Local Area Networks (LAN)
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Personal Area Networks (PAN)
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Home Area Networks (HAN)
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Wide Area Networks (WAN)
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Campus Networks
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Metropolitan Area Networks (MAN)
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Enterprise Private Networks
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Internetworks
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Backbone Networks (BBN)
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Global Area Networks (GAN)
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The Internet
PAN (Personal Area Network)
A personal area network (PAN) is a computer network used for data
transmission amongst devices such as computers, telephones, tablets and
personal digital assistants.
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CAN (Campus Area Network)
A campus network, campus area network, corporate area network or
CAN is a computer network made up of an interconnection of
local area networks (LANs) within a limited geographical area.
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LAN (Local Area Network)
A local area network is a computer network that interconnects computers
within a limited area such as a residence, school, laboratory, or office
building.
A local area network may serve as few as two or three users or as many
hundreds of users. Ethernet and Wi-Fi are the two most commonly used
LAN technologies.
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MAN (Metropolitan Area Network)
It interconnects users with computer resources in a geographic area or region
larger than that covered by even a large local area network (LAN) but smaller
than the area covered by a wide area network (WAN).
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WAN (Wide Area Network)
A wide area network (WAN) is a telecommunications network or computer
network that extends over a large geographical distance. Contains Multiple LAN’s
and MAN’s.
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GAN (Global Area Network)
Unlike local area networks (LAN) and wide area networks (WAN), GANs cover
a large geographical area.
Because a GAN is used to support mobile communication across a number of
wireless LANs, the key challenge for any GAN is transferring user
communications from one local coverage area to the next.
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Networking Terminology
Node:
In communication networks, a node is either a connection point, a
redistribution point, or a communication endpoint. Any system or device
connected to a network is also called a node. Examples include Computers,
printers, switches…
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Bandwidth:
Networking Terminology
Bandwidth is defined as the amount of information that can flow through a
network connection in a given period of time. Bandwidth is like the width
of a pipe. Or the number of lanes on a highway. Bandwidth is measured
using:
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Bps
Kbps
Mbps
Gbps
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Networking Terminology
Throughput:
• Throughput refers to actual measured bandwidth at a specific time of day, using specific Internet routes,
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and while a specific set of data is transmitted on the network.
Throughput is the amount of material or items passing through a system or process.
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References :
• Lammle, T. (2007). Cisco Certified Network Associate. Study Guide.
6th Ed. Wiley Publishing: Indianapolis, Indiana.
• Warner, K. (2003). Cisco Networking Academy Program. Companion
Guide.3rd Ed. Ciscopress: Cisco Systems Inc.
• More resources are available at:
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https://www.techopedia.com/definition/25597/computer-network
https://www.tutorialspoint.com/
https://www.searchnetworking.techtarget.com/definition
https://www.omnisecu.com/cisco-certified.../unicast-multicastbroadcast.php