Networking 1: Week 2 Quiz

Computer Networks Overview

• A computer network allows multiple computers to communicate and share resources such as data and applications.
• Networks can be classified by size, including four main types: LAN, PAN, MAN, and WAN.

Types of Computer Networks

• LAN (Local Area Network)

  • Connects computers within a small area like a building or office.
  • Utilizes inexpensive hardware (hubs, network adapters, Ethernet cables).
  • Offers high data transfer rates and security.

• PAN (Personal Area Network)

  • Designed for individual personal devices within a range of about 10 meters (30 feet).
  • Thomas Zimmerman pioneered the concept of PAN.
  • Examples include Body Area Networks (device mobility) and offline home networks.

• MAN (Metropolitan Area Network)

  • Covers a larger area than LAN by connecting multiple LANs.
  • Employed by government agencies for citizen communication and services.
  • Uses protocols like RS-232 and ADSL for connectivity.

• WAN (Wide Area Network)

  • Spans extensive geographical regions, including states and countries.
  • The internet is the largest example of a WAN.
  • Utilizes telephone lines, fiber optics, or satellites for connections.

Internetworking

• Extranet

  • Internet-based network allowing external access with credentials.
  • Comprises at least one connection to an external network.

• Intranet

  • A private organizational network accessible only to authorized members.
  • Facilitates internal communication, real-time information sharing, and collaboration.

Network Topologies

• Differentiated into physical topology (geometric representation) and logical topology (data flow representation).

• Point to Point Topology

  • Simplest topology with a direct link between two computers.
  • Cost-effective for small networks but prone to failure if the common link breaks.

• Bus Topology

  • All stations connect through a single backbone cable.
  • Common for Ethernet networks, uses CSMA for access.
  • Vulnerable to system failure if the backbone cable fails.

• Ring Topology

  • Each node connects to two others forming a continuous loop.
  • Data flows in one direction, using token passing for access control.
  • Can halt operations if a node fails due to its closed loop structure.

• Star Topology

  • All nodes are connected to a central hub or switch, which is often a server.
  • Uses coaxial or RJ-45 cables for connections.
  • Highly popular due to simplicity and reliability.

• Tree Topology

  • A hierarchical structure combining bus and star topologies.
  • Features a root node with descendant nodes, allowing one path for data transfer.

• Mesh Topology

  • Each computer connects with multiple redundant paths.
  • Commonly used in WANs and wireless networks, offering high reliability.
  • Number of connections can be calculated using the formula: Number of cables = (n*(n-1))/2, where n is the number of nodes.

Summary of Network Topologies

• Point-to-Point: Direct link, simple, cost-effective.
• Bus: Single backbone cable, widely used, prone to failure.
• Ring: Unidirectional loop, uses token passing, can fail on node failure.
• Star: Central hub, popular for reliability, easy to install.
• Tree: Hierarchical structure, blends bus and star characteristics.
• Mesh: Multiple interconnections, highly reliable, used in critical communications.