1.3

• What does LAN stand for?

  Local Area Network
• What area does LAN usually cover?

  LAN covers a small geographical area
• What does a LAN usually consist of?

  A collection of computers + peripheral devices, typically on a single site (e.g. a school)
• Give 3 advantages to LAN

  - Folders + files can be stored on a server which can be accessed by any authorised computer on the network

  
  

  - User profiles + Security can be managed centrally

  
  

  - Peripheral devices (e.g. printers) can be shared

  
  

  - Software can be distributed across all computers on a network

  
  

  - All files can be backed up centrally
• Name 2 disadvantages of LAN

  - Managing large networks can be complex

  
  

  - Malware may be able to infiltrate a network and infect every computer
• What does WAN stand for?

  Wide Area Network
• What is a WAN, and give an example of a famous WAN

  A WAN is a collection of computer networks connected together by a 3rd party (e.g. virgin media, BT etc)

  
  

  The Internet is an example of a WAN
• True or False: large organisations may have their own private WAN

  True - e.g. to connect offices from all over the country, a WAN might be used to connect the LANs of each office together
• What is bandwidth?

  The theoretical maximum amount of data that a communications channel can carry at one time.

  Bandwidth is the main factor affecting network performance
• What is bandwidth measured in?

  megabits per second (Mbps)
• True or False: the lower the bandwidth, the faster data is transferred

  False - The higher the bandwidth, the faster data is transferred
• True or False: Increasing the number of devices connected to a network, network performance decreases

  True - this is because the avaliable bandwidth is used up
• Name 1 bandwidth intensive task

  Streaming video
• What is latency?

  The time delay between the moment that transmission of data begins to when it is recieved at it's destination
• What are transmission errors?

  Errors in transmission due to noise (energy interference that degrades the quality of a wireless signal)
• What is distortion in transmission errors?

  A change in shape of the recieved signal
• What happens if a transmission error occurs?

  The data has to be retransmitted
• What can interference be caused by?

  Interference can come from mobile phones, microwaves etc.

  
  

  Thick walls between the router and wifi device can also result in a weak wireless connection
• List the 5 factors that affect network performance

  - Bandwidth

  - Latency

  - Transmission Errors

  - Interference

  - Number of devices connected
• What is a client-server network?

  A network that consists of clients (computers which request services and resources from the server) and servers (a powerful comouter that provides services or resources required by the clients)
• What is a peer-to-peer (P2P) network?

  A network where all computers are cabled or wirelessly connected together.

  All the computers have equal rights
• How are computers configured on P2P networks?

  They are configured so that each comouter shares specific files/folders with other computers (that are authorised to access them) on the LAN
• Give 3 qualities of client-server networks

  - A central backing store is avaliable to all computers

  
  

  - Security is controlled centrally

  
  

  - Backups are carried out centrally

  
  

  - All users are reliant on accessing information from the server

  
  

  - Can scale up or down
• Give 3 qualities of P2P networks

  - Storage facilities are distributed accross all computers

  
  

  - Security is local to each device

  
  

  - Backup is done by each device

  
  

  - Easy to set uo for small businesses and homes

  
  

  - cheaper than client-server networks

  ​
• What does WAP stand for?

  Wireless Access Point
• What does a WAP do?

  It recieves data from a network via a physical connection, and converts data into radio waves which are transmitted wirelessly.

  
  

  This means any device on the network with a reciever can access the data wirelessly
• True or False: a WAP does not provide a wireless connection to a switch or router

  False - it does
• True or False: A WAP is not the same as a wifi router

  True
• What is a router?

  A device designed to route data packets accross a WAN.A router is used to connect separate networks together
• What is a MAC address?

  A unique hardware address assigned to a device by the manufacturer.
• What is a switch?

  A component of a LAN that learns the MAC address of each device connected to it. This allows it to forward packets to only the intended recipient
• What does NIC stand for?

  Network Interface Card
• What does an NIC do?

  It connects devices to a network. This can be wirelessly, or wired via an ethernet connection
• True Or False: A device doesn't neccesarily need an NIC to connect to a network

  False - all devices that connect to a network must have an NIC
• What is Ethernet?

  A family of network protocols that describe how devices should format data for transmission between computers on the same network
• What is twisted pair copper cable used for?

  Connecting devices on LANs
• What is Copper Coaxial Cable used for?

  TV and Broadband in some locations where it has not been replaced by fibre optic cables
• What is good about fibre optic cables?

  They have a large bandwidth, fast transmission speeds and do not degrade as easily as copper cables
• What is the internet?

  A world wide collection of interconnected networks that is not owned or managed by one group of people.
• What is the difference between the internet and the world wide web?

  The internet is the network that connects things together.

  
  

  The World Wide Web is all public websites or pages that can be accessed. These can be accessed using the internet.