- [Craig] In this video, we explore the various hardware which is needed to connect a standalone computer to a local area network.
(uplifting piano jingle)
Every computer connected to the network will need a network interface controller.
Sometimes, this is referred to as a network interface card.
But today, a separate card inside the computer is often not necessary and it's already built into the hardware.
A network interface controller can connect a device to a wireless or a wired network.
The network interface controller uses what is known as a protocol,
a set of rules that governs how communication between the device and the connected media or wireless should occur.
A wireless access point allows wireless-enabled devices to access the network without cables.
This is clearly more convenient, although the bandwidth is often lower.
Wireless access points on a larger local area network extend the range to different parts of a building
and provide a wired connection back to a switch.
On a home network, the wireless access point is also often a router and a switch.
Security is more of a concern with these wireless connections.
A switch sends data between computers on a local area network.
They effectively segment the network by only sending traffic to the correct device on another switch.
They learn where devices are on the network by reading the from address on each packet that they receive.
If they recognise the to address, they can route data packets to the correct connection.
If not, they will broadcast the packets to all connections.
Switches very quickly learn which computers are connected and build up an internal index.
Years ago, the same functionality had to be provided by a combination of hubs and bridges.
Today, these have been superseded with switches almost entirely.
A router sends data between networks,
creating a wide area network from a number of local area networks.
You cannot connect to a wide area network such as the internet without a router.
Unlike a switch that uses the network interface controller address to route traffic,
a router uses an IP address - an Internet Protocol address - to route traffic.
Connections between desktop computers and a switch or router are usually achieved with a wired connection.
This ensures maximum bandwidth, security and reliability.
The wired connections are made of twisted pairs of wires, which are twisted around each other to reduce interference.
There is normally a set of wires for transmission and a set of wires for receiving data.
Different grades of copper insulation material can affect the quality of the cable - and therefore, the bandwidth.
These copper cables are referred to as twisted pair, unshielded twisted pair, UTP, CAT5, CAT6 or Ethernet cables.
Another type of copper cable known as coaxial cable can also be used, but it's less popular in computer networking today.
This is the cable used to connect a TV to a Freeview box and an aerial.
Fibre-optic cables use light to transmit data.
They can cover much longer distances than copper cables and have a higher bandwidth due to reduced interference.
They are therefore used in high-traffic connections such as between switches and to remote buildings.
The backbone of the internet is made of fibre-optic cables.
So, let's just recap what we've learned.
A network interface controller connects a device to a wired or wireless network connection.
A network interface card uses a protocol to ensure successful communication.
Wireless access points allow wireless-enabled devices to access the network.
Wireless connections are popular because it avoids the need to install cables.
Bandwidth on a wireless connection is lower than a wired connection,
and security is more of a problem.
A switch sends data between computers on a local area network.
A switch uses the network interface card address on a device to route traffic.
And a switch sends data between networks.
A router is needed to connect a local area network to a wide area network.
A router uses the IP address on a device to route traffic to other routers.
Connections between desktop computers and a switch are usually made with unshielded twisted pair copper cable.
Copper cable is cheap and flexible, which makes it easy to install.
Longer-distance cables and wide area networks are usually connected with fibre-optic cable.
And fibre-optic has a higher bandwidth than copper and suffers from less interference.
(uplifting piano jingle)