1.3: COMPUTER NETWORKS, CONNECTIONS AND PROTOCOLS TRE fin Flashcards
What is a LAN?
local area network
computers connected over a small area
uses own infrastructure
eg, home/small company networks
what is a WAN?
wide area network
connects computers over a large geographical area
uses third party hardware and cabling
>eg satellites, phone lines, fibre optic
eg, multi-national banking networks, internet
what is the internet?
the physical components that connect together to make a network of networks
what is the world wide web?
the software that runs on the internet (websites)
what is the cloud?
a (usually) remote compuer
why is an IP address needed?
each computer has a unique IP address which is needed to communicate with networks, etc
what is the maximum value of an IP address?
255, as 256 is a binary number
what does a domain name system (DNS) do?
allows you to type a name into your browser
this then translates the web address(URL) into an IP address
how many DNS ‘root’ servers are there and what do they do?
there are 13 DNS ‘root’ servers that hold all names and IP addresses
other DNS servers hold parts of the database
what is an ISP?
internet service provider
each one has a unique IP address and goes between your device and the internet
what is a network host?
a computer or other device connected to a network.which offers information, resources and applications to users
a host is needed to have a website
what is a domain name?
a URL
these are governed by a DNS which gives you autonomy over a small section of the internet
domain name registrars sell domain names to the public
what are the factors affecting network performance?
latency, bandwidth and error rate
what is latency?
the amount of time taken for a packet of data to get from one point to another
it is measured as the time required to get the data back to the sender
what is bandwidth?
the amount of data that can be transmitted in a fixed amount of time
it is expressed in beats per second (bps)
what is error rate?
the number of errors encountered during data transmission.
the higher the error rate, the less reliable the connection or data transfer is
what is a peer to peer network?
all computers have equal status, so all devices can act as a client or server and can provide network services
no additional hardware or software is needed for this sort of network
what is a client-server network?
relies on a central server and all clients request services from the server
additional hardware is needed- a high end, powerful server