Aice Comp sci Unit 2

Communication Notes

Overview of Networking Concepts

  • Benefits of Networking Devices

    • Allows sharing of resources such as printers and files.

    • Cost efficiency in software licensing.

    • Centralized data storage and backup.

    • Facilitates communication via email and messaging.

  • Network Types

    • Local Area Network (LAN): A network that covers a small area, such as a building.

    • Wide Area Network (WAN): A network covering a large area, connecting multiple LANs.

    • Metropolitan Area Network (MAN): Larger than LAN but covers smaller than WAN, such as a university campus.

Networking Models

  • Client-Server Model:

    • Utilizes dedicated servers for managing resources.

    • Provides centralized control over resources and access permissions.

    • Suitable for large user bases requiring security and data integrity.

  • Peer-to-Peer Model:

    • Each node (computer) serves as both client and server.

    • Lacks centralized management, less secure.

    • Good for small networks with frequent user interactions.

Client Types

  • Thin Client:

    • Relies heavily on a server or internet connection to function.

    • Limited processing capabilities; requires constant connection.

  • Thick Client:

    • Can operate both offline and online.

    • Has its own processing power and storage capabilities.

Network Topologies

  • Bus Topology:

    • Single central cable connects all devices; easy to expand.

    • If the central cable fails, the entire network fails.

  • Star Topology:

    • Devices connected to a central hub/switch.

    • Increased security and reduced data collisions; if the hub fails, network goes down.

  • Mesh Topology:

    • Each device connects to multiple others, allowing for multiple pathways.

    • Expensive and complex to set up, but offers high redundancy.

  • Hybrid Topology:

    • Combination of various topologies.

    • Adaptable to specific organizational needs but can be complex.

Cloud Computing

  • Public Cloud: Shared infrastructure, accessible over the internet.

  • Private Cloud: Dedicated infrastructure for a single organization with restricted access.

  • Hybrid Cloud: Combination of public and private cloud utilising both environments.

Wired and Wireless Networks

  • Wired Networks:

    • Utilize cables (twisted pair, coaxial, and fiber optic) for connections.

    • More secure and stable; higher data transfer rates.

  • Wireless Networks:

    • Use radio waves for connectivity, allowing mobility.

    • Prone to interference and security risks.

Essential Network Hardware

  • Router: Directs data between different networks; enables internet connection.

  • Switch: Connects devices on a LAN, directing data to specific destinations.

  • Hub: Simple device that connects multiple devices but sends all data to all devices.

  • Modem: Converts signals for internet connectivity (analog to digital and vice versa).

  • Network Interface Card (NIC): Allows devices to connect to a network, containing a MAC address.

IP Addresses and DNS

  • IP Addressing:

    • IPv4: Uses 32-bit addressing; allows for around 4 billion unique addresses.

    • IPv6: Uses 128-bit addressing; allows for vastly more addresses and is essential for future internet expansion.

  • DNS: Translates domain names (e.g., www.example.com) to IP addresses for locating resources on the internet.

Bit Streaming

  • On-Demand Streaming: Files are streamed from a server as needed.

  • Real-Time Streaming: Captures an event live and transmits immediately.

  • Importance of Buffers: Buffers manage the temporary storage of data to ensure smooth playback and mitigate data transmission delays.

Differences between Internet and WWW

  • Internet: Global network of interconnected computers and servers.

  • World Wide Web (WWW): A collection of multimedia web pages accessed via the internet using web browsers.