Hardware

• What is an NIC

  • A NIC is known as a Network Interface Controller 
  • It is an internal piece of hardware 
  • It allows a device to connect to a network  
  • Every computer connecting to a network will need one 
  • They follow a protocol (set of rules) to determine how the connection should work

  
• Where NICs are located

  • NICs used to be on separate cards 
  • Nowadays they are built into the motherboard
• What NICs can connect to

  NICs allow a device to connect to either a wired or wireless network
• What is WAP

  • A WAP is known as a Wireless Access Point 
  • It allows wireless enabled devices to connect to a network without cables (It is basically a switch that allows devices to connect wirelessly) 
  • To connect, devices need a wireless NIC - this is often built in 
  • If it is not, you can use a USB dongle - HDMI dongles are popular for TVs

  
• What are the downsides of using a WAP

  • They have less bandwidth than a wired connection 
  • Security is more of a concern with wireless connections 
  • Connection is sometimes not as strong or as reliable as wired connections
• How do WAPs work on a larger LAN

  • WAPs on a larger LAN extend the range to different parts of the building 
  • They provide a wide connection back to the switch
• How do WAPs work on a home network

  On a home network, the WAP is also often a router and a switch
• What does a Switch do

  • A switch connects devices on a LAN 
  • It sends data between 2 devices on a LAN and does this by: 
  • Switches receive data in units called frames from one device 
  • They then transmit this data to the device on the network with the correct MAC address 
  • Switches very quickly learn which devices are connected and use this to transmit data in an intelligent way - A switch uses an NIC to transmit data

  
• What does a Router do

  • A router transmits data between networks 
  • They're always connected to at least 2 different networks 
  • Routers direct data in units called packets to their destination  
  • A router creates a WAN from a number of LANs , and you cannot connect to a WAN without using a router 
  • A router uses an IP address to transmit data

  
• Where routers are used

  • Routers are used in homes and offices to connect the LAN to the internet 
  • Most home routers are in fact a router , switch and WAP all-in-one 

  
• Ports in a typical office router

  • The ADSL port connects to the internet 
  • The Ethernet port connects to the LAN

  
• Wired ethernet connections benefits

  • Wired Ethernet Connections are fast and reliable 
  • They assure maximum bandwidth and security
• Ethernet cables

  Wired Ethernet networks can use different types of Ethernet cables to connect devices on a LAN
• Twisted pair cables

  • The most common Ethernet cables are CAT 5e and CAT 6 
  • They are twisted pair cables, containing 4 pairs of copper wires which are twisted together  
  • Doing this reduces internal interference 
  • In twisted pair cables, there is normally a set of wires for transmission and a set of wires for receiving

  
• Coaxial cables

  • Coaxial cables are made of a single copper wire surrounded by a plastic layer of insulation and a metallic mesh 
  • This provides shielding from outside interference 
  • The grade of copper and insulating material affects the quality of the overall cable and therefore the bandwidth

  
• Fibre optic cables

  • Fibre optic cables transmit data as light 
  • They are high performance - so are therefore expensive 
  • They don’t suffer interference and can transmit over very large distances without loss of signal quality 
  • They have a greater bandwidth than copper wires 
  • The backbone of the Internet is built on fibre optic cables

  
• Wireless Networks and their benefits

  • Like mobile phones and TV’s, wireless networks use radio waves to transmit data 
  • Wireless networks are more convenient than wired networks as you can move around while still being connected 
  • They are also cheaper as you need fewer wires
• What are the 2 most common wireless technologies?

  • Bluetooth 
  • Wi-Fi
• Bluetooth

  • Bluetooth is usually a direct connection between 2 devices so that data can be shared 
  • Connection range varies, but mobile devices are typically 10 metres 
  • Low bandwidth compared to Wi-fi 
  • Often used in mobile / wearable devices - these include smartphones watches and headphones

  
• Wi-Fi

  • Can be used by multiple devices to connect to a LAN at the same time 
  • Connections have a range between 40 metres and 100 metres 
  • High bandwidth compared to Bluetooth 
  • Often used in the home - this includes routers , desktops, laptops , smartphones etc