1.3 Network types and performance

• What is a network?

  A network is more than one computer system connected together allowing for communication and sharing of resources.
• What are the main types of networks categorized by geographical distance?

  • Local Area Network (LAN)
  • Wide Area Network (WAN)
• What is a Local Area Network (LAN)?

  A LAN has computer systems situated geographically close together, usually within the same building or small site.
• What is a Wide Area Network (WAN)?

  A WAN has computer systems situated geographically distant from each other, possibly across a country or the world.
• How does a Client-Server Network function?

  Clients make requests to a server, which manages the request and responds.
• What is the role of a server in a Client-Server Network?

  The server controls network security, backups, and can be upgraded to manage higher demand.
• What is a Peer- to- Peer Network?

  A Peer-to-Peer Network allows data to be shared directly between systems without requiring a central server.
• What is a disadvantage of Peer-to-Peer Networks?

  Without a dedicated server, there is no central device to manage security or backups.

  computer performance will decrease as more devices connec to the network
• What is a Local Area Network (LAN) infrastructure typically owned by?

  The network infrastructure of a LAN is usually owned and managed by the network owner.
• What is a Wide Area Network (WAN) often reliant on?

  WANs often use third-party communication channels, such as connections by internet service providers.
• What are data packet?

  • broken down files for sending across a network
  • this allows data to be transferred across a network quickly
  • each packet of data is redirected by routers across a network till it arrives at destination
  • they may be split up taking alternative routes
• What does network topology refer to?

  Network topology refers to the layout of computer systems on a local network.
• What are the two types of network topology mentioned?

  • Star Topology
  • Mesh Topology
• How does a Star Topology work?

  Each computer system is connected to a central device, usually a hub or switch.
• What is an advantage of Star Topology?

  • A star topology has improved security because data packets are sent directly to and from the hub/switch.
  • new systems can be attached directly without shutting down system
  • fast transfer speed as there are minimal network collisions
• What is a disadvantage of Star Topology?

  If the central system (the hub or switch) fails, then the whole network will be unusable.
• How does a Mesh Topology work?

  In a full mesh network, each computer system is connected to every other computer system.
• What is an advantage of Mesh Topology?

  • If one cable or system fails, data packets can take an alternative route to reach the destination address.
  • can withstand large amounts of data traffic
• What is a disadvantage of Mesh Topology?

  This network layout can be expensive to install and maintain due to the large amount of cables required.
• What factors can affect the performance of a network?

  • Bandwidth available
  • Interference (e.g., thick walls)
  • Applications being used
  • Number of users at the same time
  • Distance to travel / signal strength
  • Server / CPU performance
  • Number of data collisions
  • Amount of data to transfer
• What is bandwidth?

  Bandwidth is the maximum amount of data that can be sent across a network at once.
• What is the purpose of a checksum in a data packet?

  A checksum is a calculation on the data to see if any errors or corruption have occurred during transmission.
• What is the difference between a full mesh and a partial mesh network?

  A full mesh network connects every computer system to every other system, while a partial mesh connects only some nodes to every other node.
• What are the advantages and disadvantages of Star and Mesh topologies?

  Star Topology:

  Advantages:

  • Improved security
  • Easy to add new systems
  • Minimal network collisions

  
  

  Disadvantages:

  • Requires extra hardware
  • Central system failure affects the whole network

  
  

  Mesh Topology:

  Advantages:

  • Alternative routes for data
  • Can withstand large amounts of traffic
  • New systems can be added without disruption

  
  

  Disadvantages:

  • Expensive to install and maintain
  • Possible redundant cabling
• What are data packets?

  Data packets are smaller parts into which files are broken down for transfer across a network.
• Why are data packets used instead of whole files for transfer?

  Data packets allow data to be transferred quickly across a network.
• How do routers function in data transfer?

  Routers redirect data packets across networks until they reach their destination.
• What happens to data packets when they arrive at their destination?

  They are reassembled back into the original file.
• What is the purpose of a Wireless Access Point (WAP)?

  A Wireless Access Point provides a link between wireless and wired networks.
• Can you give an example of a Wireless Access Point in a public space?

  A WiFi hotspot in a coffee shop or airport is an example of a Wireless Access Point.
• What is the function of a router?

  Routers transfer data packets between networks.
• How do routers determine the best route for data packets?

  Routers use the IP address in the packet header to determine the best route.
• What is the role of a switch in a LAN?

  A switch connects devices together on a LAN.
• How does a switch forward data packets?

  A switch reads the destination address in the packet header and forwards the data directly to its destination.
• What is a Network Interface Card (NIC)?

  A NIC is an internal piece of hardware required for a computer to connect to a network.
• What is the function of a MAC address in a NIC?

  A MAC address is used when sending data across a LAN.
• What are the three common types of transmission media?

  • Ethernet cables: Used on LANs, examples include Cat5e and Cat6.
  • Fibre Optic cables: Very fast, used for WANs, data sent as pulses of light.
  • Coaxial cables: Older, slower, copper cables affected by electromagnetic interference.
• What is the internet?

  The internet is a global network of interconnected networks.
• How is the World Wide Web (WWW) different from the internet?

  The WWW is a way of accessing information using protocols like HTTPS, while the internet is the underlying network.
• What is the role of servers on the internet?

  Servers provide services on the internet, such as hosting web pages.