Network Components

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Switches

  • Connects devices in a network; Cables are connected to ports; The switch is intelligent enough to know the addresses of connected nodes.
  • Active data management as Data packets received by switch; examined for destination; sent to port of destination device
  • Core / Backbone switch: Manages data being received by all switches
  • A switch can be configured:  Limiting bandwidth; QoS (Quality of Service); priority to applications – e.g. VC or VoIP ; Virtual LAN; Monitoring traffic

Hubs

These are sometimes referred to as multi-port repeaters. That is they receive data and broadcast it to all the output ports. A hub cannot screen network traffic unlike a switch. It does not know the addresses of connected nodes.

Looks physically same as a switch; Connects devices in a network

Passive as data packets are received; data packets are not examined; data packets are sent to all ports; each device has to filter unwanted data packets; More susceptible to interception; More collisions

Wireless Access Points (WAP)

  • A wireless ‘hub’; Connected to main network infrastructure usually by a cable to a switch
  • Wireless enabled devices can connect: laptops ; PDAs ; mobile phones
  • Radio signals are sent by devices to WAP, sent from WAP on to the network OR sent as wireless signal for recipient device to receive
  • Issues with hacking but can be overcome by encryption

Network Interface Card (NIC)

This a card that enables a computer to be connected to a network using a cable. It is Part of a computer Connected to motherboard and Enables network cable to be connected. Each NIC has a unique address called MAC (media access control) address, enabling it to be uniquely identified.

Wireless Network Interface Card

  • Connects wirelessly to WAPs ; Can be: part of laptop circuitry; USB wireless dongle
  • adaptor card to fit into PCMCIA slot on laptop or motherboard of desktop computer
  • Must conform to same standard as WAP; Has a MAC address

Routers

  • A communications device (can be hardware or software) which receives data and forwards it to the correct location via an appropriate route. Can be a modem as it allows an internal network to connect to the internet.
  • Can be used to connect two LANs together even if they use different protocols
  • Used to connect LAN to WAN; Similar to a switch but has external connection
  • Stores addresses of connected devices; Used by businesses and available to home users

Repeaters

A device used to link two cable segments.

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