Transcript 02-network_l1_teacher-powerpoint

Unit 1.5 - Network
Topologies, protocols
and layers
Lesson 1
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Big picture
Most computers and devices are connected
together via networks. This opens up new
opportunities and advantages.
What are the advantages?
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Learning Objectives
• Students will be able to identify a Star and
Mesh Topology
• Students will be able to compare
Advantages and Disadvantages of Wi-Fi
and Ethernet
• Understand and explain what encryption is
and why it is required
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What is a Network?
• A computer network is a number of
computers linked together to allow them to
share resources. Networked computers can
share hardware, software and data.
– BBC Bitesize
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Engagement Activity
• Networks are all around you, in school, at
home in businesses and hospitals.
• Think about what these networks look like
• Draw a diagram to represent one of these
networks. Include the parts, devices and
wires
• Be ready to explain your diagram
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Write a definition of these in your notes
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Topology
Mesh Network
Star Network
WiFi
Encryption
Ethernet
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Activity 1
• You will be given some string and cups.
• Create a Mesh Network
• Create a Star Network
• Think about and discuss the features of
each.
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Activity 1 - Answer
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Activity 1 - Answer
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Content
• A Mesh Network is ….
• Where some or all of the workstations or other devices are
connected directly to each of other. Most are usually connected to
the node that they exchange the most data with.
• A Star Network …..
• In a star network, each device is connected by an individual cable
directly to the server. Star networks are usually the layout of choice
in schools and offices because they tend to be the most reliable of
the topologies.
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Activity 2
• You will be given a selection of cards that
show the advantages and disadvantage's
of Wired and Wireless networks (Ethernet
and WiFi)
• Sort the into groups
• Compare you answers with other
students.
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Activity 2 - Answer
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WiFi
• WiFi is Wireless Frequency
- radio waves are used to transmit data packets
without the need for wires.
• This method is slower and more
vulnerable to attack but it removes the
need for cabling and networks
• This means that it can be set up in remote
locations such as in vehicles, in parks or
on planes etc.
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WiFi Frequency and Channels
• https://www.youtube.com/watch?v=3YHov
kP1JC8
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Encryption
• Encryption is a method of scrambling data with a
key code which makes no sense.
• On an open or public WiFi network anyone can
join and sniff out packets of data from other
users.
• Therefore encryption is used. If intercepted the
data will have no meaning
• In order to read the data the user is required to
decrypt the data using the key.
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Content
• When you are using a secure site for example
your bank, or purchasing on Amazon, encryption
applied to keep your details safe:
• The encryption method used is called 'SSL'
(Secure Socket Layer).
• A tiny padlock appears in your browser window,
usally on the left hand side of the address bar
and the website address starts with HTTPS://
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Twitter example
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Consider Twitter
• Twitter users a HTTPS when you log in,
why?
• Why does the data need to be encrypted?
• What could happen if it was not
encrypted?
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Encryption video
• https://www.youtube.com/watch?v=w0Qbn
xKRD0w
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Encryption task
http://www.cryptoclub.org/
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Encryption task
• http://www.cryptoclub.org/games/ro
gue_computer.php
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Key Words Recap
• Topology
• Mesh Network
• Star Network
• WiFi
• Encryption
• Ethernet
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Plenary
• Answer some questions from the exam
papers on the topics
• Create a short animation or film on
Network security.
Stretch yourself!
• Code an encryption program using a
programming language of your choice.
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