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Topic 8 - Networks - Coggle Diagram
Topic 8 - Networks
Lesson 1 - Computer Networks
Server
computer that stores data to be shared with connected computer
Client
accesses services from the server, relies on the network for data
Communication Media
how data is transported, often cables or wireless
eg. fiber optics, ethernet, WiFi
Resources / Peripherals
devices connected to the computer, with a specialized function
eg. printer, keyboard, mouse, photocopier
Routers
connects devices in the same building, connects networks together
often used in homes and businesses to connect to the internet
Switches
stores network devices' MAC addresses, checks which devices asked for data
Network Interface Card
small circuit boards connected to the motherboard, allow desktop and laptops to access the network
Modem
converts digital signals to analogue, transports them through a telephone line, and another modem converts it back at the other end
allows a computer to connect to the internet
User
the person accessing the network through a device
Protocols
the rules of how data is converted into data packets and transferred across the network
Advantages and Disadvantages
Advantages
Easy communication
Roaming, data accessed anywhere on the network
data shared easily
Resources / peripherals can be shared easily
software shared easily
Disadvantages
dependence on the network
easier to hack
more difficult to set up a complicated network
easier to share viruses and malware
Lesson 2 - Wires or Wireless
Wireless networks VS Wired networks
Wireless networks > Wired
add components easily
more efficient
can be accessed on the move
don't require dedicated computers
easier and cheaper to install
many businesses (eg. hotels, cafes) have WiFi 'hot spots'
Wired networks > Wireless
more exposed to attacks from unauthorized users
wireless can have interference, data can be lost
steel reinforcing materials can block consistent wireless coverage
wired transmission is often quicker
Types of communication media
Wired
Ethernet cables
Fibre optic cables
Twisted pair
Coaxial
Copper
Wireless
WiFi
uses radio waves, splits the signal into pieces, transmits data over several frequencies
can connect to more devices
faster bandwidth
Bluetooth
uses radio frequencies (not infrared like most remote controls)
eliminate need for both a wired connection and a line of sight
limited number of connections
often used for headsets or phones
slower bandwidth
Lesson 3 - Main types of Networks
Topologies
Bus
Description
nodes are connected to a cable running across the network
the central cable is called the backbone
data is sent up and down the backbone until it reaches the correct node
not well suited for large amounts of data
Advantages and Disadvantages
Disadvantages
network fails if backbone is broken
terminators are needed at each end of the backbone
one backbone increases the chance of data colisions
slow
Advantages
cheaper
less cabling needed
easy to connect nodes
Star
Description
nodes are indirectly connected via switches or hubs
switches only send data to the correct node
hubs send data to every device
the switch acts as a point for all communication to pass through
large networks are usually controlled by servers
found in large organisations and home networks, especially wireless ones
Advantages and Disadvantages
Advantages
if one node or its link fails, none of the others are affected
new nodes can be added easily
faster, fewer data collisions
higher performance, data only passed on to its intended node
Disadvantages
the network fails if the switch fails
lots of cable required, more hardware needed
can be very expensive in large networks
