[3.1] Networks & Topologies

• What is a network?

  A network is two or more devices connected together to share resources.

  
• Define a Local Area Network (LAN).

  A LAN is a network within a small geographical area, usually under 1 mile.

  
• Define a Wide Area Network (WAN).

  A WAN is a network spanning a large geographical area, made up of connected LANs and uses external hardware such as satellites and telephone lines.

  
• What is an advantage of having a network?

  Users can share resources like printers and internet connection and users can access files and communicate easily from any computer on the network.

  
• What is a disadvantage of having a network?

  There is an increased security risk to data from malware or hackers.

  
• True or False?

  A LAN uses networking hardware owned by the organisation.

  True.

  LANs use hardware owned by the company/organisation, not shared public infrastructure.

  
• True or False?

  A WAN connects networks over a small area like a home.

  False.

  A WAN connects networks over a large geographical area spanning miles.

  
• Give an example of networking hardware used in WANs.

  WANs use routers, telephone lines, fibre optic cables, and satellites to connect LANs.

  
• What are the 5 key factors that affect network performance?

  The 5 factors that affect network performance are:

  Number of users

  Bandwidth

  Latency

  Error rate

  Transmission media

  
• Define bandwidth.

  Bandwidth is the amount of data that can be transmitted per second, measured in bits per second.

  
• Define latency.

  Latency is the delay between data being sent and received.

  
• Define error rate.

  The error rate measures how many data packets do not reach their destination.
• What is transmission media?

  Transmission media refers to the cable type used for wired network connections.

  
• Which transmission media has the highest bandwidth?

  Fibre optic cables have the highest bandwidth compared to copper cabling.

  
• What causes an increased error rate?

  An increased error rate occurs with less reliable connections like poor wireless signals.
• What happens if the maximum bandwidth is used?

  If the maximum bandwidth is used, devices cannot transmit data until bandwidth frees up.
• True or False?

  More users increase the amount of bandwidth available

  False.

  More users reduce the available bandwidth per user, potentially slowing the network.
• How can you decrease latency?

  Using higher bandwidth or more reliable transmission media can decrease latency.
• Describe the client-server model.

  The client-server model has dedicated server machines that provide services to client machines.

  
• What is the role of a server?

  A server manages resources like internet access, printing, email, backups, and security.

  
• Describe the peer-to-peer model.

  In a peer-to-peer model, all computers are equal peers with no dedicated servers. Each computer is responsible for managing its backups, security and connections.

  
• What is an advantage of a client-server network?

  Centralised backups, updates, and security makes managing the network easier.

  
• What is a disadvantage of a client-server network?

  Servers are expensive to purchase and maintain, and require specialist IT staff.

  
• What is an advantage of peer-to-peer?

  Peer-to-peer networks are very easy to maintain and cheap to set up.

  
• What is a disadvantage of peer-to-peer?

  Each user must manage their own backups, updates, and security on their device.

  
• True or False?

  Most homes use a client-server model.

  False.

  Most homes use a peer-to-peer model without dedicated server machines.
• True or False?

  A server failing is a single point of failure for the network.

  True.

  If the central server fails, all client machines lose access to network services.
• What is the role of a router?

  A router routes data between different networks like a LAN and the internet (WAN).

  
• What is a wireless access point (WAP)?

  A WAP allows wireless devices to connect to a wired LAN.

  
• What does a switch do?

  A switch connects multiple wired devices to a LAN and routes data between them.

  
• What is a network interface card (NIC)?

  A NIC allows a computer to send and receive data on the network.

  
• Define transmission media.

  Transmission media refers to the cables used for wired network connections.

  
• What are the three main transmission media types?

  The three main types of cable are:

  Unshielded twisted pair (UTP)

  Coaxial cable (copper)

  Fibre optic cable

  
• Which transmission media has the lowest bandwidth?

  Unshielded twisted pair (UTP) cable has the lowest bandwidth.

  
• Which transmission media is immune to electrical noise?

  Fibre optic cables are unaffected by electrical noise.

  
• True or False?

  Switches are active devices that inspect data.

  True.

  Switches are active devices that inspect network data to route it efficiently.
• Define the Internet.

  The Internet is a massive collection of interconnected networks spanning the world.

  
• What is the difference between the Internet and World Wide Web?

  The Internet provides connectivity, while the World Wide Web is the collection of web pages accessed via browsers.

  
• What is the role of an Internet Service Provider (ISP)?

  An ISP provides internet access and connects the user's network to the Internet.
• What does DNS stand for?

  DNS stands for Domain Name System.