1.3.3 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 devices from different manufacturers don’t have problems communicating
why is protocol layering used?
-breaks tasks down into manageable units
-to apply protocols in order / one after the other
-to provide independence of layers
what is the Internet?
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?
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 address
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 address
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 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 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
what are benefits of packet switching?
-multiple methods to ensure data arrives correctly
-multiple methods to arrive to destination, if one breaks can always go through another route
-transfer packets over a very large network
what are drawbacks of packet switching?
time is spent deconstructing
and reconstructing the packets
what are benefits of circuit switching?
-data arrives in logical order which results in a quicker reconstruction of data
-enables two users to hold a call without any delay in speech
what are drawbacks 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 client-server networking?
a relationship between terminals
(computers) and a single server which allows them to communicate, and share resources
what are benefits of client-server networking?
-increased security
-central single backups
-data and resources can be shared
what are drawbacks 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
what are benefits of peer-to-peer networks?
-cheaper to set up
-easy to share resources
-easy to maintain
what are drawbacks of peer-to-peer networks?
-can be used to contribute towards piracy
-each computer has to be backed
up independently
