Understanding Computer Networks and Their Characteristics

Sep 10, 2024

Fundamentals of Information Technology: Lecture Notes

Overview of Computer Networks

  • Understanding computer networks and their uses.
  • Characteristics that define important features of computer networks.
  • Different types of networks existing globally.

Definition of a Network

  • A network is a set of devices, referred to as nodes, connected via communication links.
    • Nodes: Computers, printers, or any devices capable of sending/receiving data.
    • Links: Cables, air, optical fibers, or other mediums for transporting signals.

Network Criteria

  1. Performance
    • Depends on the performance of network elements.
    • Measured in terms of delay and throughput.
  2. Reliability
    • Indicates failure rate of network components.
    • Evaluates availability and robustness during failures.
  3. Security
    • Protection against data corruption, unauthorized access, and exploitations.
  4. Type of Connection
    • Point-to-point (single transmitter/receiver) vs. multi-point (multiple recipients).
  5. Topology
    • Types of data transmission: unicast, multicast, broadcast.
    • Unicast: One-to-one transmission.
    • Multicast: Sending data to multiple users at once.
    • Broadcast: Transmitting information to all nodes in a network.

Characteristics of Computer Networks

  1. Performance
    • Transit Time: Time taken for a message to travel from one device to another.
    • Response Time: Time between inquiry and response.
  2. Reliability
    • Frequency of network failures and recovery time from those failures.
  3. Energy Efficiency
    • Energy consumed per unit of successful communication; importance due to climate change concerns.
  4. Security
    • Protecting data from unauthorized access and manipulation.
  5. Fairness
    • Equal distribution of resources to all users.
  6. Adaptability
    • Ability to adapt to environmental changes.
  7. Channel Utilization
    • Efficiency of bandwidth use for effective communication.
  8. Throughput
    • Amount of data successfully transferred in a period.
  9. Scalability
    • Ability to accommodate more users/devices.
    • Horizontal and vertical scalability.

Data Sharing in Networks

  • Data can be accessed and stored on network servers.
  • Examples: Google Drive for easy access and backup.
  • Benefits of network storage:
    • Accessibility from anywhere.
    • Easier distribution and collaboration.
    • Automatic updates.
    • Backup facilities.

Types of Networks by Geographical Scope

  1. Personal Area Network (PAN)
    • Range: ~1 meter; connects devices close to an individual (e.g., Bluetooth).
  2. Local Area Network (LAN)
    • Range: up to a few kilometers; connects devices within a building or campus.
  3. Wireless Local Area Network (WLAN)
    • Similar to LAN but uses wireless connections (e.g., Wi-Fi).
  4. Metropolitan Area Network (MAN)
    • Covers a larger geographic area than LAN but smaller than WAN (e.g., city-wide).
  5. Wide Area Network (WAN)
    • Covers large distances; connects multiple LANs (e.g., the Internet).

Conclusion

  • Understanding how networks function and their characteristics is crucial in the field of information technology.
  • Different types of networks serve various purposes and operate over different geographical ranges.