SAM HARRIS TECH REVISION

1.3 Networks, Connections and Protocols (OCR J277)

1.3.1 Networks and Topologies

• Types of Networks: LAN (Local Area Network) and WAN (Wide Area Network).
• Factors Affecting Performance: Bandwidth, number of users, transmission media, and latency.
• Client-Server vs Peer-to-Peer: Centralised management vs decentralised data sharing.
• Hardware: NICs, Switches, Routers, Hubs, and WAPs.
• The Internet: A global network of networks; DNS (Domain Name System), Hosting, and The Cloud.
• Star and Mesh Topologies: Advantages and disadvantages of central hubs vs interconnected nodes.

1.3.2 Wired and Wireless Connections

• Wired: Ethernet (twisted pair/coaxial) and Fibre optic cables.
• Wireless: Wi-Fi (frequencies and channels) and Bluetooth.
• Encryption: Protecting wireless data using standards like WPA/WPA2.

1.3.3 Protocols and Layers

• IP and MAC Addresses: Logical (software) vs physical (hardware) identification.
• Common Protocols: TCP/IP, HTTP/HTTPS, FTP, POP3, IMAP, and SMTP.
• The Concept of Layers: Dividing network tasks to reduce complexity and allow interoperability.

Related Past Paper Questions

• Year: 2023
  Identify two advantages of using a star network topology instead of a mesh network topology.
  Mark: [2]
• Year: 2023
  Explain the purpose of a router in a network.
  Mark: [2]
• Year: 2022
  Describe the difference between a Local Area Network (LAN) and a Wide Area Network (WAN).
  Mark: [2]
• Year: 2022
  Explain how the use of layers can help when developing network protocols.
  Mark: [3]
• Year: 2021
  State the purpose of the Domain Name System (DNS).
  Mark: [2]
• Year: 2021
  Identify two factors that can affect the performance of a wireless network.
  Mark: [2]
• Year: 2020
  Describe what is meant by a 'Client-Server' network model.
  Mark: [2]
• Year: 2020
  Explain the function of the Transmission Control Protocol / Internet Protocol (TCP/IP) stack.
  Mark: [4]
• Year: Sample Paper
  Define the term 'Network Protocol'.
  Mark: [1]
• Year: Sample Paper
  Identify the protocol most likely used to retrieve an email from a server and explain why.
  Mark: [3]