Here I describe about basic knowledge of Computer Networks. It's also sylabus for studying computer networks.

1. Submitted to:
Pranab Bandhu Nath
Senior Lecturer
Department of Computer Science & Engineering
Submitted By:
Sujon Kumar Dey
ID No: 1834902519
Section B
Program: CSE (Day)
Class Note: 01
Course : Computer Networks
Course Code : CSE 317
Date of Submission: 09/05/2021
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2. COMPUTER NETWORKS
ARPANET:
ARPANET is the shortest form of Advanced Research Projects Agency Network.
History of ARPANET is interesting, because it's the start of INTERNET.
ARPANET is built up for research purposes, it's funded by the Pentagon. It mainly
starts with telephone lines.
Reason of the ARPANET is that military commanders want a computer
communication system without a central core. Finally the defense department
successfully made a call in January 1969 Bolt, Berenek, and Newman (BBN) of
Cambridge, Massachusetts, won the $1 million contract.
Network:
Network is the meaning of connection. After invenstion of stream engine, network
idea was established. In computer system, network mean the connection of
minimum two computer system.
Computer Network:
A computer network is a set of computers connected together for the purpose of
sharing resources. This connection can be made by wire or wireless. Common
example: Internet, exchange files, or allow electronic communications.
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3. Goals Of Computer Network:
● Sharing Resource
Sharing Resources from one computer to another computer over. Like when we
share files or communicate with each other.
● Performance
Performance is one of the major issues in networking, because we always want
speedy data transmission and communication.
● Reliability
Without reliability, computer networks can not be a secure or efficient
communication system. A reliability network system is ensured to use an
alternative for data transmission if any hardware issue or connectivity issue.
● Scalability
For increasing performance and reliability using more resources is the scalability.
● Security
Security is also another main goal of computer network systems.
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4. Application of Computer Network:
● Business Applications
For business purposes, we must communicate with each other. Like B2B, B2C or
marketing between customers. Without networking it’s not easier or effective.
● Communication Medium
The modern telecommunication system is totally dependent on communication
medium, computer networks provide us with a wire/wireless medium. Different
type cables, microwave communication also.
● E-Commerce
Electronics commerce is another invention and application of computer network
systems. It helps us receive products from home with a cheap price and less work.
● Home Applications
Home applications like Micro Oven, Washing machine, Air Conditioning System,
Remote control base Television and other electronics components are the example
application area of computer networks.
● Mobile Users
Today’s mobile is not limited with call to each other, now using mobile network
data communication like internet use, roaming is also possible. This is possible by
computer networks.
Component of Computer Network:
There are mainly three types of components in the Computer Network.
1. Hardware Equipment
2. Software
3. Cables and Connectors
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5. Hardware Components:
➢ NIC : NIC full form is Network Interface Card. It's the most important
hardware device for connecting with the Internet. Without NIC it is not
possible to connect over with a Network, then it’s not possible to share
resources or communicate anything.
➢ Server: Server is the HOST of the computer network. It’s sharing resources,
data and services to build up the network.
➢ Client: Clients are the users who access the resources, services and data.
➢ Peers: Peers stand for Peer to Peer. It’s actually the device which connects
the users.
➢ Transmission: For data to be sent and received we must need a transmission
system and transmission media. Transmission media can be wire or wireless
systems.
➢ Medium: Medium are the media between devices, it can be a cable, also it
can be wireless.
➢ Router: Router is used for connecting between more than one devices. It’s a
central point of all devices that are connected within the network.
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6. ➢ Bridge: Bridge is a hardware device, it can create signal, aggregate it for
multiple device communication. It’s work is the same as a repeater.
➢ Hub: Hub is a hardware device, which allows creating networks between
multiple devices through a cable, like ethernet. Hub can broadcast data in
every port which is connected with the device.
➢ Switches: Multiple devices can connect with a switch through their data
cable. Switch can connect different devices to network devices.
➢ Gateway: Gateway is the gate between two networks. It may be a router,
firewall, server, or other device that enables traffic to flow in and out of the
network.
➢ Repeaters: Repeater is a device that works as a signal amplifier. It receives
a signal and amplifies it, then it again transmits it.
Softwares:
➢ Network Operating System: Network Operating System is Computer
Operating System (OS) which actually is used for specific large or small
networking systems. Like workstation, personal computers, Local area
network etc.
➢ Protocol Switches(TCP/IP, OSI): Protocol is the rules of communication
between two or more devices. Actually, it allows devices to communicate
between each other, regardless of any differences in their internal processes,
structure or design.
There are several types of network protocol. Like TCP/IP, OSI model.
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7. Transmission Control Protocol/Internet Protocol (TCP/IP) is a
communications architecture used for networking computers and to
communicate across the Internet.
Otherhand, The OSI Model (Open Systems Interconnection Model) is a
conceptual framework used to describe the functions of a networking
system.
Cables and Connectors:
● Twisted pair cable: Twisted pair cable, from the name it's clear that it's a
wire with twisted wire. Twisted wire is use due to reduce the noise of the
cable. Because normal cable genrating huge noise with their signal. There
are two types twisted cable.
1. Unshielded Twisted Pair (UTP)
2. Shielded Twisted Pair (STP)
There are also categories Twisted Pair Cable. This cables name Category 1
to Category 7.
● Coaxial cable: Coaxial cables, commonly called coax, are copper cables
with metal shielding designed to provide immunity against noise and greater
bandwidth. Coax can transmit signals over larger distances at a higher speed
as compared to twisted pair cables.
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8. ● Fiber-optic cable: A fiber optic cable is a network cable that contains
strands of glass fibers inside an insulated casing. They're designed for
long-distance, high-performance data networking, and telecommunications.
Compared to wired cables, fiber optic cables provide higher bandwidth and
transmit data over longer distances. Fiber optic cables support much of the
world's internet, cable television, and telephone systems.
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