1.3 - Computer networks, connections and protocols Flashcards
What does LAN stand for?
Local Area Network
What is a LAN?
- Covers a small geographical area
- All hardware is owned by the organisation that uses it
- Either wired or wireless
Where would you often find LANs?
- Businesses
- Schools / Universities
- Homes (connects PCs, TVs, Printers etc)
What are some advantages of using a LAN?
- Sharing files is easier
- You can share the same hardware
- Internet connection can be shared between every device that is connected
- You can install/update software simultaneously rather than one-by-one
- User accounts can be stored centrally
- You can communicate w/ LAN users cheaply & easily
What does WAN stand for?
Wide Area Network
What is a WAN?
- Connects LANs that are in different geographical locations
—> A network that is spread over a large geographical area - They use third party infrastructure
How are WANs connected?
May be connected using fibre or copper telephone lines, satellite links or radio links
Give an example of a WAN:
The internet
What are the types of Network connection devices?
- Hubs
- Switches
- Wireless access points
- Routers
What is an NIC?
Where is it found?
- Internal piece of hardware
- Allows a device to connect to a network
- Used to be on separate cards but now built into the motherboard
What is the purpose of a Switch?
Connects devices on a LAN
They receive data from one device & transmit this data to the device on the network (with the correct MAC address)
In what units do Switches receive data?
Frames
What is Routers responsible for?
Transmitting data between networks
Where are Routers used & why?
In homes & offices to connect the LAN to the internet
What is the role of Routers on the internet?
Directing data (packets) to their destination
What are the most common Ethernet cables & what are they?
CAT 5e & CAT 6
‘Twisted pair’ cables, contains 4 pairs of copper wires which are twisted together
What is the purpose of the ‘4 pairs of copper wires which are twisted together’ in an Ethernet cable?
To reduce internal interference
What are coaxial cables made of?
A single copper wire surrounded by a plastic layer and a metallic mesh
What is the purpose of the plastic layer in a Coaxial cable?
Insulation
What is the purpose of the metallic mesh in a Coaxial cable?
Provides shielding from the outside interference
What is the purpose of a Fibre Optic Cable?
To transmit data as light
What are the advantages of a Fibre Optic Cable?
- Greater BANDWIDTH = transfer speeds are faster
- Can transmit over VERY LARGE DISTANCES without LOSS OF QUALITY
What are the disadvantages of a Fibre Optic Cable?
- Very Expensive
What is Radio waves used for in a wireless network?
To transmit data