(Done) 1. Networks Flashcards
(55 cards)
1
Q
Define LAN
A
- Local area network
2
Q
Features of a LAN
A
- Covers a small geographical area located on a single site
- All the hardware for the LAN is owned by the organisation that uses it
- Is either wired or wireless
3
Q
Reasons to use a LAN
A
- Sharing files is easier - Networks can access the same files, work collaboratively on them and copy them between machines
- You can share the same hardware on an LAN (In context, multiple people using the same printer)
- The internet connection can be connected to every device on the LAN
- You can install software on all the computers at once instead of one by one
- You can communicate with LAN users cheaply and instantly e.g. with instant messaging
- User accounts can be stored centrally so users can log in on any device on the LAN
4
Q
Define WAN
A
- Wide area network
5
Q
Features of a WAN
A
- A WAN connects LAN in different geographical locations to each other
- Organisations hire infrastructure from telecommunications companies who own and manage the WAN
- WANs can be connected via fibre or copper telephone lines, satellite links or radio links
6
Q
Function of network interface controllers
A
- An internal piece of software that allows a device to connect to a network
7
Q
Function of switches
A
- Connect devices on a LAN
- Receive data from one device and transmit the data to the device with the correct MAC address
8
Q
Function of routers
A
- Responsible for transmitting data between networks, always connected to two networks
- Have a crucial role in the internet, directing packets to the correct location
- Used to connect the LAN to the internet
9
Q
Types of ethernet cables
A
- CAT 5e and CAT 6
- Coaxial
- Fibre optic
10
Q
Features of CAT 5e and CAT 6 ethernet cables
A
- Are ‘twisted pair’ cables which contain four copper wires which are twisted together to reduce internal interference
11
Q
Features of Coaxial ethernet cables
A
- Made of a single copper wire surrounded by a plastic layer for insulation and a metallic mesh which provides shielding from outside interference
12
Q
Features of fibre optic cables
A
- Transmit data as light
- High performance
- Don’t suffer interference and can transmit over large distances without suffering loss in quality
13
Q
Features of Bluetooth
A
- Usually a direct connection between two devices so that data can be shared
- Connection range varies but mobile devices are usually 10 meters
- Low bandwidth compared to WiFi
- Often used in mobile or wearable devices
14
Q
Features of WiFi
A
- Can be used by multiple devices to connect to a LAN at the same time
- Connection range between 40 and 100 metres
- High bandwidth compared to Bluetooth
- Often used in the home
15
Q
Pros of wireless compared to wired connection
A
- More convenient as you can move around
- Cheaper as you need fewer wires
16
Q
Function of a wireless access point
A
- Performs the function of a switch wirelessly
17
Q
Function of wireless NIC USB dongles
A
- Can be plugged into computers to allow them to connect wirelessly to the internet
18
Q
Function of wireless NIC HDMI dongles
A
- Can use wireless networks to stream high-quality video to a TV
19
Q
Define bandwidth
A
- The amount of data that can be transferred in a given time
20
Q
What factors have an effect the performance of a network
A
- Available bandwidth and how many devices are demanding it
- If a network is wired or wireless
- Wireless connection is dependant on signal quality and interference
- Wired connections depend on the type of wires used
- Choice of hardware other than cables
- Choice of topology
21
Q
Features of a client-server network
A
- Managed by a central server that has clients connected to it
- Files are stored centrally on the server instead of individual client device
- Clients sends requests to the server, which the server then processes and then responds
- The server stores user profiles, passwords and access information
- Most uses of the internet work on a client-server relationship
22
Q
Pros of client-server networks
A
- Easier to keep track of files as they are stored centrally
- Easier to perform back-ups
- Easier to install and update software
- Easier to manage network security
- Servers are very reliable and are always on
23
Q
Cons of client-server networks
A
- Expensive to set up and pay IT specialists to set up and maintain
- Server dependence
- The server may struggle if there are many users trying to access it at the same time
24
Q
Features of a peer-to-peer network
A
- All devices are equal, connecting to each other directly without a server
- Files are stored on individual devices and shared with each other
- You may use a P2P network at home to share files between devices, or connect devices to a printer
25
Pros of a P2P network
- Easy to maintain - No expensive hardware needed
- No dependence on the server
26
Cons of a P2P network
- No centralised management
- Copying files between devices creates duplicate files
- Peer machines are less reliable and data may be lost if one fails
- Machines are prone to slow down when other machines access them
27
Features of a star topology
- All devices are connected to a central switch or server
- The central switch allows many devices to access the server simultaneously
- Star topologies may be wired or wireless
28
Pros of star topologies
- If a device fails or is disconnected, the rest of the network is unaffected
- It is simple to add more devices to the network
- Better performance than other setups - data goes straight to the central device so data can be transmitted all at once
29
Cons of star topologies
- In wired networks, every device needs a cable to connect to the central switch or
server - This can be expensive
- If there is a problem with the switch/server, the whole network is affected
30
Features of mesh topologies
- Decentralised - networking devices are either directly or indirectly connected to each other
- There is no single point where the network can fail
- Wired and wireless
- Full mesh - All devices connected to every other device
- Partial mesh - Not all devices directly connected
31
Define network standard
- A set of agreed requirements for hardware and software
32
Define network protocol
- A set of rules for how devices communicate and how data is transmitted across a network
33
Define communication protocol
- Specify how communication between devices must start and end, how the data must be organised and what the devices must do when the data goes missing
34
Define MAC addresses
- A unique identifier assigned to every network enabled device by the manufacturer that cannot be changed
35
Uses of MAC addresses
- Mainly used by ethernet protocols and LANs
- LAN switches read the MAC address and use them to direct data to the correct device
36
Uses of IP addresses
- Used when sending data over TCP/IP networks
37
Difference between IPv6 and IPv4
- IPv6 uses 128 bits, with 16 bit sections with each one given as a hexadecimal number
- IPv4 uses 32 bits, with 8 sections, each assigned a denary number
38
Define TCP/IP
- The protocol that dictates how data is sent between networks
- Made up of the transmission control protocol and the internet protocol
39
Function of TCP
- Set the rules for how a device connects to a network
- In charge of splitting the data into packets and reassembling the packets into the original data once they reach the device
- Responsible for checking data sent is delivered
40
Function of IP
- Responsible for directing packets to their destination across the network
41
Define HTTP
- Hyper text transfer protocol
- Used by web browsers to access websites and communicate with webservers
42
Define HTTPS
- Hyper text transfer protocol secure
- A more secure version of HTTP
- Encrypts all information sent and received
43
Define FTP
- File transfer protocol
- Used to access, edit and move files between devices on a network
44
Define POP3
- Post office protocol version 3
- Used to receive emails from a server
- The server holds the email until you download it then it is deleted from the server
45
Define IMAP
- Internet messages access protocol
- Used to retrieve emails from a server
- The server holds the email until you delete it, you only download a copy
- Used by most web based email clients
46
Define SMTP
- Simple mail transfer protocol
- Used to send emails
- Also used to transfer emails between servers
47
Define a layer in network protocols
- A group of protocols which have similar functions
48
Features of layers
- Layers are self-contained, they don't depend on the other protocols on the same layer
- Each layer performs the hidden work needed for actions on the layer above
49
Advantages of using layers
- Breaks communication into manageable pieces which allows devs to focus on one area at a time
- Layers are self contained so can be changed without affecting other layers
- Having standards for each layer forces companies to make compatible and universal hardware and software
50
Define the world wide web
- A collection of websites that are hosted on webservers accessed through the HTTP
51
Define URLs
- Addresses used to access webservers and the resources on them
52
Define domain name service
- Used to translate website domain names into IP addresses through domain name servers which store IP addresses and matching domain names
53
How does the cloud function
- Businesses can use their servers to offer a range of services - clients can access data storage, software and processing power remotely over the internet
54
Advantages of cloud
- Can access files and applications from any connected device
- Easy to increase how much storage is available
- No need to buy expensive hardware
- No need to pay IT staff to manage the hardware
- Cloud host provides security and backups
55
Disadvantages of cloud
- Need connection to the internet
- Dependant on the host for security and backups
- Data stored is vulnerable to hackers
- Expensive
- Unclear who owns the data
