Explain the Hardware Required in Networking


In order for a computer network to exist and function correctly there are several components necessary
The main features all networks have are:
  • Communication Links
  • Hubs
  • Switches
  • Nodes
  • and Routers


Communication Links
  • There are many types of Communication Links that allow devices to transfer information
    • Wired
      • Cables (LAN)
      • Fibre Optic Cables
    • Wireless
      • Radio Waves
      • Microwaves

Wired Communication
  • Copper Cables
    • Cables, such as an Ethernet Cable, are the most common form of local data transfer
    • The most common form of cable is the Ethernet Cable that connects devices to make a Network
  • Fiber Optic Cables
    • Fiber Optic Cables are one of the fastest methods for transferring data
    • They work as a guide for the light that is sent through the cable
    • There are two types of Optical fibers
      • Multi-Mode Optical Fiber (MMF) which is used in shorter connections (below 1050m) and allows more than one user to use the cable
      • Single-Mode Optical Fiber (SMF) is used in longer connections but is smaller in diameter than the MMF cable
      see this side for more information: http://www.lanshack.com/fiber-optic-tutorial-network.aspx

Wireless Communication
  • Radio Waves
    • Radio Waves are most commonly used in radios where people can "Tune in" when they want to
    • Radio waves are only short range, since you cannot tune in to a radio program across the world
  • Microwaves
    • Micro Waves are fast small electromagnetic waves that are used in various forms of communication and can transfer data at a rate of up to 5 Ghz and can transfer much more information than radio waves
    • Microwaves can be streamed from one device to another specific device
    • Microwaves occur in Wireless communication such as WiFi, Bluetooth and the ISM band
    • They are the most common form of local wireless communication

Node
  • A device in a network
  • A node can be a communication point (switch), redistribution point (hub) or an end-point (computer)
  • A node is capable of sending, receiving, or forwarding information


Hub vs switch
Switches are essentially 'intelligent' hubs. Both switches and hubs enable multiple network devices to connect to each other. The network devices are connected to either a switch or a hub, which is connected to other network devices. If one device then sends data, it goes to the switch/hub and from there it moves on the to the other network devices.
Differences between hubs and switches:
  • Hubs will send data they receive out on every port. The network device connected to that port has to determine itself whether the data is relevant for it or not. This means that the network bandwidth is shared between all devices.
    • Ex.: a hub with 100Mb/s is used and two devices communicate with each other and need 10Mb/s for this communication, then the other devices only have 90Mb/s of bandwidth left, even though they don't participate in the communication of the two first devices.
  • Switches, in contrast, send the data only where it is supposed to go. They have memorized at which port all devices are by saving those devices' MAC addresses and to which port they are connected to.

  • Switches can 'listen' at all ports simultaneously, enabling devices to send data at any time.
  • Switches process the data in order to find out where to send it, resulting in some short delays due to this processing. Since hubs don't process the data, this delay isn't present there.
  • Switches are usually more expensive than hubs.


Router
  • A router forwards data packages to a specific address after checking the package for information



Images

hub.jpg
A basic Hub

Switch.jpg
A Switch

Router.jpg
A Router with wireless antennas


Created by: Jocbe, Daniel GIllo
Last update: 20. January 2011

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