Networks

Computer
Networks

What is Networking?

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This is the connection between two or more computers to pass information and
resources.

Networks Fundamentals

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Must be two or more computers connected via cable or wirelessly

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Allows users to share data

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Gives access to shared peripheral devices eg. office printers, fax machines, scanners

Advantages of Networks

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Allows the exchange of information between users and data sharing

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Allows communication over distance between users. E.g emails

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Security

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Storage Capacity e.g data stored on servers

Disadvantages of Networks

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Setting up a Network for the very first time can be quite expensive

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Because all systems are connected to a centralised server, when compromised a virus
can spread to all other systems

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A network requires regular maintenance due to advanced configurations and
complicated installations

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If the network is down, users can’t access files and folders.

Characteristics of Computer Networks

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Speed - How fast data can be sent too and from computers in a network

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Cost - Expenses it is to implement the network and maintenance

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Security- How secure is the network, protection against viruses and malware attacks

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Reliability- How capable the network is to provide the intended service

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Topology- The arrangement of a network that comprises nodes and connecting lines
via sender and receiver

Types of Networks

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Local Area Network(LAN)

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Wireless Local Area Network(WLAN)

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Wide Area Network(WAN)

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Metropolitan Area Network(MAN)

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Internet

Local Area Network

A collection of devices connected together in one physical location, such as a building, office,
or home. A LAN can be small or large, ranging from a home, office or school network.

Wide Area Network

A wide area network (WAN) is a telecommunication network that extends over a large
geographic area.

ISP- Internet Service
Provider

Internet

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The world-wide system of computer networks

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Facilitates worldwide communication and access to data resources through a vast
collection of private, public, business, academic and government networks

Types of Network Topology

Topology refers to the layout or structure of a network in relation to the flow of data. There are various

types of network topology in a computer network, such as:

●Bus Topology

●Ring Topology

●Star Topology

Bus Topology

Bus topology employs a single cable (Bus) to connect all the nodes. The main cable serves as the
network’s spine.

Advantages

●Less cabling: A common wire connects all nodes in a bus topology.

●Less Expensive: Bus topology is less expensive because it uses a common wire.

●Small network: This is best suited for situations where only a few computers are required for

connection establishment.

●Upgradeable: A new node can be added or removed in this topology without affecting the

other nodes.

Disadvantages

●Reduced signal strength: To connect a more significant number of nodes, we must increase the

number of Taps, Drop Lines, and the central cable. And increasing these things will weaken the

signal.

●Core failure: If the main central cable becomes damaged or faulty, the entire network will fail.

●Low security: This is a significant security issue because all nodes in the network can hear what

data is transmitted to other nodes in the network.

Open Ended

Give one advantage of the Bus Topology!

Ring Topology

Ring Topology is a topology in which each computer is linked to another on both sides. The last
computer is linked to the first, forming a ring. This topology enables each computer to have exactly two
neighbors.

For example, if Node A wishes to send data to Node

D, Node A has two options for doing so. That is to

say –

●Node A > Node F > Node E > Node D

●Node A > Node B > Node C > Node D

Advantages

●Token system: Only nodes that have tokens can transfer data.

●Less Cabling: As every node manages the cable to its closest neighbor, it requires less cabling.

●Easier troubleshooting: It is less challenging to manage and install because the nodes or cable

flaws are easily discernible.

Disadvantages

●Difficult to upgrade: Adding or removing nodes is problematic because it disrupts network

activity.

●Failure of a network: When one system crashes, it disturbs the overall network activity.

Open Ended

What is a Ring Topology?

Star Topology

A hub connects all computers in this type of network topology. A central node connects all other nodes.
You can use this type of network topology on LAN networks due to its low cost and ease of setup.

Advantages

●Network failure prevention: Only the affected nodes will fail, while the remaining nodes will

continue to function.

●Performance: High performance with a small number of nodes and very little network traffic.

●Upgradation: This topology makes adding, deleting, and moving devices simple.

Disadvantages

●Expensive: The cost of installing star topology is high.

●Slow connection: Heavy network traffic can sometimes significantly slow the bus.

Open Ended

What is a Star Topology?

What If

You are a prominent network engineer, who was asked to determine which network
topology should be implemented for Bajan International Bank. In your vast knowledge of
networks you are to type a very detailed document, giving advice on which network you
prefer and convince BIB to pay for such a network. The network suggested may be any of
your choice.

Intranet

An intranet is a private network contained within an enterprise that is used to securely share
company information and computing resources among employees. An intranet can also be used for
working in groups and teleconferences. Intranets encourage communication within an organization.

Extranet

An extranet is a controlled private network that allows access to partners, vendors and suppliers or an authorized
set of customers – normally to a subset of the information accessible from an organization's intranet.

Cabled Media

Twisted Pair/ Ethernet Cable: this is one of the most popular forms of network cable, it resembles a
telephone cable but is slightly larger. The longer the cable the weaker the signal.

Coaxial Cable: A type of copper cable specially built with a metal shield and other components engineered
to block signal interference. It is primarily used by cable TV companies to connect their satellite antenna
facilities to customer homes and businesses.

A fiber-optic cable, also known as an optical-fiber cable, is an assembly similar to an electrical cable but
containing one or more optical fibers that are used to carry light. The optical fiber elements are typically
individually coated with plastic layers and contained in a protective tube suitable for the environment where
the cable is used. Different types of cable[1] are used for different applications, for example, long-distance
telecommunication or providing a high-speed data connection between different parts of a building.

Activity

You are asked to assist your friend who doesn’t know which cable to purchase. The fiber
optics or the cable for his new apartment. Your friend wants the best internet because he
hosts live podcasts on the weekend. Convince your friend which is best and give reasoning
behind your answer.