1. Introduction to Networks

1.2. Types of Networks

a) Local Area Network (LAN)

  • Definition: A network confined to a small geographic area, such as a building or campus.
  • Characteristics:
    • High-speed communication.
    • Limited number of connected devices.
  • Examples: Office networks, home networks.

b) Wide Area Network (WAN)

  • Definition: A network that spans large geographic areas, connecting multiple LANs.
  • Characteristics:
    • Slower speeds compared to LAN.
    • Uses public networks (e.g., the internet) or leased lines.
  • Examples: The Internet, corporate WANs.

c) Metropolitan Area Network (MAN)

  • Definition: A network that covers a city or metropolitan area.
  • Characteristics:
    • Larger than LAN but smaller than WAN.
    • Often used by ISPs or city governments.
  • Examples: City-wide Wi-Fi networks, cable TV networks.

d) Personal Area Network (PAN)

  • Definition: A network for personal device communication within a short range.
  • Characteristics:
    • Limited to an individual.
    • Typically wireless.
  • Examples: Bluetooth devices, smartphone hotspots.

3. Network Topologies

Definition:
The physical or logical arrangement of nodes (devices) and connections in a network.

a) Star Topology

  • All devices are connected to a central hub or switch.
  • Advantages:
    • Easy to manage and troubleshoot.
    • Failure of a single device doesn’t affect others.
  • Disadvantages:
    • Central hub failure disrupts the network.

b) Mesh Topology

  • Each device is connected to every other device.
  • Advantages:
    • High reliability and fault tolerance.
    • Data can take multiple paths.
  • Disadvantages:
    • Expensive and complex to set up.

c) Bus Topology

  • All devices share a single communication line (backbone).
  • Advantages:
    • Simple and cost-effective for small networks.
  • Disadvantages:
    • Collision issues with increased devices.
    • A backbone failure affects the entire network.

d) Ring Topology

  • Devices are connected in a circular structure.
  • Advantages:
    • Predictable data transmission.
  • Disadvantages:
    • A single break disrupts the network.

e) Hybrid Topology

  • Combines two or more basic topologies (e.g., star-bus, star-ring).
  • Advantages:
    • Flexible and scalable.
  • Disadvantages:
    • Higher cost and complexity.