What is a Computer Network?

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Table of Contents
Abstract......................................................................................................................3
Introduction ...............................................................................................................4
Computer Network Classification ................................................................................4
Geographic Coverage: .............................................................................................4
Interconnection .......................................................................................................5
Administration ........................................................................................................5
Architecture ............................................................................................................5
Computer Network Types ...........................................................................................5
A. Personal Area Network (PAN) .............................................................................5
B. Local Area Network (LAN)..................................................................................6
C. Network of Metropolitan Area (MAN) .................................................................6
D. Wide Area Networking (WAN) ............................................................................6
Computer Network Models .........................................................................................7
A. OSI Model ..........................................................................................................7
B. Internet Model ....................................................................................................7
Physical Layer ............................................................................................................8
A. Digital Transmission ...........................................................................................8
B. Transmission Media ............................................................................................9
Magnetic Media ...................................................................................................9
Twisted Pair Cables ........................................................................................... 10
Coaxial Cable .................................................................................................... 10
Power Lines ....................................................................................................... 10
Fiber Optics ....................................................................................................... 11
Data Link Layer ....................................................................................................... 11
A. Error Detection and Correction ......................................................................... 12
Detecting Errors ................................................................................................ 12
REDUNDANCY CHECK ON A CYCLIC BASIS (CRC) .................................... 12
Data Link Control and Protocols ............................................................................... 13
A. Flow Control ..................................................................................................... 13
Stop and Wait .................................................................................................... 13
ARQ Selective Repetition ................................................................................... 14

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Network Layer .......................................................................................................... 14
A. Unicast Routing ................................................................................................ 14
B. Broadcasts Routing ........................................................................................... 15
C. Multicast Routing ............................................................................................. 15
D. Anycast Routing................................................................................................ 15
Transport Layer ....................................................................................................... 16
Transmission Control Protocol............................................................................... 16
Application Layer ..................................................................................................... 16
A. Client Server Model .......................................................................................... 16
Socket ................................................................................................................... 17
Remote Procedure Call (RPC) ............................................................................... 17
Network Security Issues ............................................................................................ 17
A. Interruption ...................................................................................................... 18
B. Privacy Breach .................................................................................................. 18
C. Integrity............................................................................................................ 18
D. Authenticity ...................................................................................................... 18
Applications .............................................................................................................. 18
References ................................................................................................................ 19

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Abstract
Computer networks, also called data networks, are types of telecommunications
networks that allow computers to communicate with each other. Computer networks
use data links to carry data between networked devices. A network link is established
between nodes using either cable or wireless media. One of the world's most popular
networks is the Internet. A network node originates, transports, and terminates data on
a network. The node can be a computer, a phone, a server, or networking equipment.
Networking means sharing information between devices, regardless of whether they
are connected directly. Networks enable access to the World Wide Web, the use of
shared application and storage servers, printers, and fax machines, as well as the use
of email and instant messaging applications. Each computer network has its own
characteristics, from the physical media it uses to carry signals to its topology and
scale, as well as its organizational intent.
Keywords: Computer Networks, Network Classifications, Local Area Network,
Coaxial Cables, Network Security, Physical Layer

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Introduction
A computer network is a linked collection of computers and computerized
peripherals such as printers. This connectivity makes it easier for computers to
communicate information. Computers can connect with each other via either wired or
wireless media. Networking engineering involves the use of software, firmware, chip
level engineering, hardware, and electric pulses. To make network engineering easier,
the entire networking idea is separated into numerous levels. Each layer is in charge
of a distinct task and is independent of the others. However, practically all networking
operations rely in some manner on all of these levels.
The internet is a network that is made up of other networks. It is the biggest
network of any type in the world. The internet connects all WANs, which can also
link to LANs and residential networks. The Internet's protocol suite is TCP/IP, and IP
is its addressing protocol. IPv4 is widely utilized on the Internet in today's globe. Due
to a lack of address spaces, it is progressively moving from IPv4 to IPv6. The Internet
enables people to exchange and access vast amounts of information from across the
world. It involves use of the WebPages, FTP, email accounts, audio and video
streams, and other similar technologies. On a broad scale, the internet runs on Client-
Server architecture. Fiber optics offers an extremely fast backbone for networks.
Computer Network Classification
A computer network is a linked group of computers and computerized peripherals
such as printers. This connectivity makes it easier for computers to communicate
information. Computers can connect with each other via either wired or wireless
media. Computer networks are classified based on a variety of features. These are:
Geographic coverage, interconnection, administration, and architecture.
Geographic Coverage:
Based on its location, a network can be categorized into one of the following
categories. It can link Bluetooth-enabled devices across your desktop. There are
barely a few yards between them. It might be put throughout the structure, with