Networks Flashcards
What is a network
Two or more computers connected together that transmit data
What are protocols
Sets of rules defining how two devices communicate with each other
Why are protocols standard
So that devices from different manufacturers don’t have problems communicating
Describe the structure of the Internet
The Internet is a global network of
interconnected networks
What does TCP stand for?
Transmission Control Protocol
What does IP stand for?
Internet Protocol
What is the function of the application layer during data transmission?
The Application Layer specifies what protocols need to be used to relate the application to what it’s being used for
What is the role of the transport layer during data transmission
Establishes an end-to-end connection between the source and recipient computers. It also splits up the data into packets
What is the role of the network layer during data transmission
Adds the source and destination IP addresses
What is the function of the link layer during data transmission
Adds the MAC addresses to the packet
What does the application layer do when it receives data?
Presents data in the form it was sent
What does the transport layer do when it receives the data
Removes the port number and reassembles the packets
What does the network layer do when it receives the data
Removes the IP addresses
What does the link layer do when it receives the data
Removes the MAC addresses
What is a local area network
A network spread over a small geographical area / positioned on a single site
What is a wide area network?
A network spread over a large geographical area, usually requiring extra hardware
What does DNS stand for
Domain Name System
What is DNS?
The name given to the method of naming
internet resources. (.com, .uk etc)
What is circuit switching?
The process of creating a direct link
between two devices and transferring
data the entire duration of the link
What is a requirement of circuit switching?
The transfer and download rates must be
identical on both devices
What is packet switching?
A method of communicating packets of
data across a network
Give an advantage of packet switching
- Multiple methods to ensure data arrives correctly
- Multiple methods to arrive to destination, if one breaks you can always go through another route
- Transfer packets over a very large network
Give a disadvantage of packet switching
- Time is spent deconstructing and
reconstructing the packets
Give the advantages of circuit switching
- Data arrives in a logical order which results in a quicker reconstruction of data
- Enables two users to hold a call without any delay in speech
Give the disadvantages of circuit switching
- Bandwidth is wasted during periods when no data is sent
- Devices must transfer and download at the same rate
- Switches introduce electrical interference which can corrupt or destroy data
What does the header of a data packet contain?
- The sender and recipient IP addresses
- Protocols being used
- Order of the packets
- The time to live / hop limit
What does the packet payload contain?
The raw data
What does the packet trailer contain
The checksum or cyclic redundancy check
What is the purpose of a firewall?
To prevent unauthorised access to a
network
What is a firewall made up of?
- Two network interface cards
- Firewall software
What is a proxy
A web server that acts as an intermediary, collecting and sending data on behalf of a user, protecting their identity
Give two advantages of using a proxy
- Allows users to remain anonymous
- Data can be cached making it faster to load
- Reduces web traffic
What is the function of a network interface card
Connects a computer to a network
What is the function of a switch
Directs the flow of data across a network, commonly used in Star topologies
What is the function of a router?
Connects two networks together
What is the function of a gateway?
Connects two networks and translates protocols so they can communicate without any issues
What is client-server networking
A relationship between terminals (computers) and a single server which allows them to communicate, and share resources
Give an advantage of client-server networking
- Increased security
- Central single backups
- Data and resources can be shared
Name the disadvantages of client-server networking
- Expensive to set up
- Trained staff are required to maintain
the network
What is peer-to-peer networking?
A network where the terminals are all connected to each other to share resources
Give two advantages of peer-to-peer networks
- Cheaper to set up
- Easy to share resources
- Easy to maintain
Give two disadvantages of peer-to-peer networks
- Peer-to-Peer networks can be used to
contribute towards piracy - Each computer has to be backed up
independently
