Networks Flashcards
What does LAN stand for?
Local Area Network
What area does a LAN cover?
A small geographical area located on a single site
Who owns the hardware for a LAN?
The organisation that uses it
Are LANs wired, wireless, or both?
Both
Where are LANs used?
1) Businesses
2) Schools
3) Universities
What does WAN stand for?
Wide Area Network
What does a WAN connect?
LANs that are in different geographical locations
How can WANs be connected?
1) Telephone lines (copper or fibre optic)
2) Satellite links
3) Radio links
What is the biggest WAN?
The Internet
What does PAN stand for?
Personal Area Network
What area does a PAN cover?
Devices over a very short range
What devices are often connected in a PAN?
1) Smartphones
2) Smartwatches
3) Headphones
What wireless technology do PANs use to connect devices?
Bluetooth
What are the advantages of networking computers?
1) Sharing files is easier
- Network users can access the same files, work on
them at the same time and copy files between
machines
2) Can share the same hardware (like printers) between multiple devices
3) Can install and update software centrally on all computers at once
4) Can communicate easily and cheaply across a network
5) User accounts can be stored centrally, so users can log in from any device on the network
What are the disadvantages of networking computers?
1) Can be expensive to set up as a lot of extra hardware is often required
2) Networks can be vulnerable to hacking, and malware can easily spread between networked computers
3) Some networks are dependent on one or more servers
-If those servers go down it can be very disruptive
for people trying to use the network
4) Large networks are difficult to manage and may require employing a specialist to maintain them
What is a NIC used for?
Allows a device to connect to networks
What is a switch used for?
To connect devices on a LAN
What is a router used for?
1) To transmit data between different networks
2) To connect to the Internet
What is bandwidth?
The amount of data that can be sent across a network in a given time
How are devices connected in a star topology?
All the devices are connected to a central switch or server that controls the network
What are the advantages of a star topology?
1) If a device fails or a cable is disconnected, the rest of the network is unaffected
2) Easy to add more devices to the network, since each device is connected to the switch using a separate cable
3) Tend to have better performance than other setups - data goes straight to the central device so all devices can transmit data at the same time
4) Very few data collisions on a star network compared with other network topologies
What are the disadvantages of a star topology?
1) In wired networks, every device needs a cable to connect to the central switch or server. This can be expensive .
2) Switch is an expensive piece of hardware
3) Problem with switch or server affects the whole network
4) Maximum number of possible connections on the network is determined by the switch - new switch may be required for more connections
How are devices connected in a bus topology?
Bus topologies use a single ‘backbone’ cable, called a bus, to connect all the devices
Why are two terminators placed at the end of the bus?
1) Stop data reflecting back along the bus
- Without the terminators, reflected signals would cause interference and potentially make network unusable
What are the advantages of a bus topology?
1) Network is unaffected if a device fails
2) Not dependent on a central switch working to keep the whole network running
3) Relatively cheap to set up compared to star networks. The total length of wiring needed is much less, and the hardware you need is cheaper than switches, both to buy and to maintain
What are the disadvantages of a bus topology?
1) Data collisions are common. When there is a data collision the data must be resent, which slows the network down
2) More devices you add to the network , the more likely data collisions are. This makes bus topologies unsuitable for large networks
3) To try and avoid data collisions, devices must wait for the bus to be available before they can send any data - this can also slow the network down
4) if the bus cable gets broken, it splits the network into separate parts. Since the separated networks don’t have terminators at both ends of the bus, there will be a lot of reflected signals which can shut down the entire network
What is the definition of a protocol?
A protocol is a set of rules for how devices communicate and how data is transmitted across a network
How is data send between networks?
Equal-sized packets
What is a layer?
A group of protocols which have similar functions
What are the 4 layers of the TCP/IP protocol model?
Layer 4 - Application Layer
Layer 3 - Transport Layer
Layer 2 - Network Layer
Layer 1 - Link Layer
