computer networks Flashcards
What is a network?
2 or more computers connected for communication
What are some advantages of using a computer network?
share hardware sharing files monitor users activity access network from home cost of computing is reduced per user
What are some disadvantages of a computer network?
susceptible to hacking
difficult to set up so specialist staff required
lots of hardware so expensive
if a computer gets a virus the whole network goes down
if file server goes down all files are inaccessible
What is a PAN?
personal area network with a very small geographical area
What is a LAN?
local area network with a small geographical area
What is a WAN?
wide area network with a wide geographical area
What is a wireless network?
radiowaves to transmit data
What are the advantages of a wireless network?
easy to add new nodes
don’t need as many cables
allows computing devices to be used outside of work/school
What are the disadvantages of a wireless network?
low security
lower bandwith
What is a wired network?
use cables to connect devices
What are the advantages of a wired network?
high security
high bandwith
What are the disadvantages of a wired network?
high cost as there is lots of hardware
complicated installation
What is a network topology?
a network diagram with arrows showing where data is transmitted
What is a star topology?
all the devices connected to a centre switch
What is a bus topology?
all devices connected to a backbone
What are the advantages of a star topology?
if a node fails, the rest are unaffected
add more nodes simply via separate cables
better performance
fewer data collisions
What are the disadvantages of a star topology?
switch is expensive
problem with witch affects whole network
maximum number of devices
lots of wires can be expensive
What are the advantages of a bus topology?
unaffected if a node fails
cheap to set up
not dependant on central switch working
What are the disadvantages of a bus topology?
data collisions unsuitable for large networks have to wait for bus to be available can be slow whole network goes down if backbone is broken
What is a network protocol?
instructions to how data is passed over a physical network and electrical signals are transmitted
What is the TCP/IP model?
a train never leaves
1-application
2-transport
3-network
4-data link
What protocol is used to send an email from a client to an email server?
SMTP
What protocol is used to retrieve emails stored on a server?
IMAP
What protocol is used to send files from a client to a file server?
FTP
What protocol is used to make a payment securely?
HTTPS
What protocol is used to make a payment securely?
HTTPS
What protocol is used for accessing webpages?
HTTP
What protocol is used for data packets?
TCP/IP
What protocol is an alternative to TCP with no error checking?
UDP
What protocol allows electronic devices to connect to a wireless LAN?
Wi-Fi
What protocol is used by ethernet to send data frames?
Ethernet
What is a file server?
a very fast computer with lots of RAM storage where files are located on a network
What is a work station?
an individual node connected to the server
What are routers?
translates information from network to another router
control where data packets go
What are switches?
a connection point to cables from work stations and peripherals
What are the 2 data transmission methods?
serial and parallel transmission
What is authentication?
verifying the identity of a user
What is encryption?
files altered by a secret code to become unreadable to unauthorised users
What is firewall?
an application that prevents unauthorised connection to and from the internet
What is MAC address filtering?
checks the MAC address of devices and only lets specific devices into the network
