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
