ICT Year 9 - Connecting to the Internet: Networks and Devices

Definition of Computer Networks

A computer network is a group of two or more computers linked together so that they can share resources and communicate.

Advantages of Computer Networks

  • Sharing documents/files/folders/data.
  • Sharing peripherals (printers/scanners).
  • Centralized security management by a network administrator (e.g., changing passwords, monitoring internet).
  • Centralized backup.
  • Centralized file upload for sharing.
  • Software can be installed easily/centrally.
  • Access resources from any workstation.
  • Facilitates easy communication between users.

Disadvantages of Computer Networks

  • Higher installation cost (server and cabling).
  • Increased risk of spreading viruses across the network.
  • Printer queues can be problematic.
  • If the main server fails, the network stops functioning.
  • More users can slow performance.
  • Accounts can be hacked by other users.

What Networks Enable Us To Do

  • Share files.
  • Send email.
  • Share resources like printers or scanners.

Network Devices

  • Modem: A modem provides internet connectivity by modulation and demodulation; it converts digital data to analog and vice versa.
  • Hub and Switch:
    • Hub: Broadcasts data to all devices; less secure/efficient.
    • Switch: Reads destination address and forwards data to the appropriate device; more secure.
  • Router: Connects two or more networks and routes data between them (e.g., LAN to WAN). Commonly used to connect a LAN to the Internet. Functions include routing data, choosing fastest route, and adapting data format for the destination network.
  • Bridge: Connects two LANs using the same protocol to function as a single LAN.
  • Gateway: A network point that acts as an entrance to another network.
  • Network Interface Card (NIC): Allows a device to connect to a network; includes the MAC address.
  • Network Cables: Medium for data transfer; faster and more secure than Wi-Fi; copper or fiber optics.
  • Repeater: Amplifies the signal and retransmits it at higher power to extend distance.
  • Access Point (AP): A wireless device that creates a WLAN; can act as a bridge or router; contains a transceiver/antenna.

How to Set Up and Configure a Small Network

  • Setting up IP account if internet access is required.
  • Setting up the system (or buying appropriate hardware correctly configured) to allow for wireless connectivity.
  • Configuring all the hardware and software so that they work correctly together.
  • If internet is required, ensure that a high-speed broadband connection exists.
  • Putting all the common software onto a server and making sure that a network licence has been acquired so that all network users can make use of the software.
  • Setting up privileges so that each user can only access their own area or common shared area.
  • Setting up a network-manager-level of privilege so that they can monitor network usage, change password, etc.