Local Area Networks- Network Hardware

• Network Interface Controller (NIC)

  An internal piece of hardware which allows a device to connect to a network.
• What unique identifier do all NICs have?

  Media Access Control (MAC) address
• Are MAC address unique worldwide or unique to the network?

  Worldwide
• MAC Address

  A unique identifier assigned to a device that cannot be changed
• Switch

  Connects devices together on a LAN and directs frames of data (packets) to the correct device.
• Packets

  Small, equal sized units of data used to transfer files over networks
• Router

  A piece of hardware responsible for transmitting data between networks
• What does a switch use to determine where the packets go to?

  MAC Address
• What does a router use to determine where the packets go to?

  IP Address
• Wireless Access Point (WAP)

  A piece of hardware that allows devices to connect wirelessly
• Wireless Access Points (WAPs) and Routers

  A WAP may be standalone and connected to a router OR it can be part of the router itself
• Transmission Medium

  The channel which data can be sent through
• Transmission Media: Air

  • Wi-Fi and Bluetooth both use radio waves
  • Both are specific standards
  • Bluetooth generally has a smaller range (about 10 metres)
  • Bluetooth has a low bandwidth compared to Wi-Fi
  • Wi-Fi can be used by multiple devices to connect to a LAN at the same time
  • Wi-Fi has a high bandwidth compared to Bluetooth
• Bandwidth

  Bandwidth is the amount of data that can be transferred in a given time.
• Transmission Media: Copper Cables

  Ethernet Cables/ Twisted-pair copper cable

  • Data is transmitted through these using electrical signals
  • Copper is used because of its high electrical conductivity
  • However, copper cables can suffer from interference which causes transmission errors
  • Twisted cables have different ratings to indicate how quickly data can be transferred.
  • E.g. Cat-5e can transmit at 1 Gbps.
  • E.g. Cat-6 can transmit at 10 Gbps.

  Coaxial Cables

  • Coaxial cables use insulation to reduce interference
• Transmission Media: Fibre Optic Cables

  • They use pulses of light in a transparent core
  • They are high performance (and therefore expensive) cables- they do not suffer interference and can transmit over very large distances without loss of signal quality
  • Latency is very low
• Latency

  The delay
• What piece of network hardware uses IP addresses?

  Router
• An Internet Protocol (IP) address can be used to identify where data packets need to be sent to, and where they have come from.
• Wired Vs Wireless Networks: Cost

  Wired networks: installation costs can be expensive

  Wireless networks: Cheaper to set up, devices can connect if in the range of a wireless access point
• Wired Vs Wireless Networks: Installation

  Wired networks: Installation requires technical knowledge and space to install cables

  Wireless networks: Installation is simple as most wireless devices will connect automatically
• Wired Vs Wireless Networks: Maximum Transmission Speed

  Wired networks: Up to 1 gigabit per second for Ethernet

  Wireless networks: Up to 50 megabits per second
• Wired Vs Wireless Networks: Maximum Distance for Reliable Communication

  Wired networks: Up to 100 metres for Ethernet - over 2 kilometres for fibre optic

  Wireless networks: Up to 50 metres
• Wired Vs Wireless Networks: Security of Connection

  Wired networks: More secure as a physical connection is required to intercept data

  Wireless networks: Less secure as wireless signal cannot be contained within a building and no physical connection is needed to intercept data
• What tasks does a router carry out?

  • Receive packets
  • Forwards packets
  • Identify correct IP / correct location
  • Assign IP addresses to nodes/devices
  • Converts packets from one protocol to another.
• What is Bluetooth?

  A type of wireless technology.
• What is CAT5e cable?

  Contains twisted pairs of copper wires.
• What is a coaxial cable?

  A type of copper cable that consists of a central wire protected by a metal shield.
• What is a fibre optic cable?

  A type of cable that uses light to carry signals.
• State the name of the hardware device inside the laptop that connects it to the LAN.

  Network Interface Controller
• State how an Ethernet connection is different to a Wi-Fi connection.

  • Ethernet is wired.
  • Wi-Fi is wireless
• What does a switch do?

  A switch connects devices in a local area network. Data is received by the switch and sent to the device with the correct MAC address.
• What does a router do?

  A router transmits data between networks in units called packets. A router can be used to connect a local area network (LAN) to the Internet.
• What does a Wireless Access Point (WAP) do?

  A Wireless Access Point (WAP) connects devices in a local area network wirelessly using Wi-Fi.