3.1 NETWORK types and PERFORMANCE (lan, wan, topology + more)

Question 1

what is a network?

Answer 1

a network is more than one computer system connected together allowing for communication and sharing of resources

Question 2

what is a lan

Answer 2

a local area network

Question 3

features of a lan

Answer 3

• situated geographically close together (same site)
• school / office
• within the same building or small site

Question 4

what is a wan

Answer 4

wide area network

Question 5

features of a wan

Answer 5

• geographically distant computer systems
• across a country or the world
• third party communication channels

Question 6

advantages of client - server network

Answer 6

• controlled centrally and easily backed up
• hardware, software and resources shared easily over the network

Question 7

disadvantages of client - server network

Answer 7

• large amounts of data traffic congestion slows the network down
• if a fault occurs within the server then the whole network will fail
• IT technicians required to manage and maintain the network
• malware (viruses and worms) can spread quickly across the network

Question 8

advantages of peer to peer network

Answer 8

• not dependent on a server
• easy to setup
• perfect for quickly sharing files

Question 9

disadvantages of peer to peer network

Answer 9

• no central device to manage security of backups
• computer performance decreases the more devices connected

Question 10

what are data packets?

Answer 10

data broken down into smaller parts

Question 11

what happens when all the packets arrive at the destination?

Answer 11

data is reassembled back into an original file

Question 12

what is the header of a packet?

Answer 12

source address
destination address
packet number
protocol

Question 13

what is the payload of a packet?

Answer 13

the data itself

Question 14

what is the trailer of a packet?

Answer 14

a calculation on the data to see if any errors or corruption have occured during transmission

Question 15

what is network topology?

Answer 15

the layout of computer systems on a network

Question 16

what is a name for devices in a network (and topology diagram)?

Answer 16

nodes

Question 17

what are the two types of topology?

Answer 17

star and mesh

Question 18

how does star topology work?

Answer 18

each computer system connected to the central hub / switch
the hub / switch looks at the destination address and transfers the packets directly

Question 19

what are advantages of star topology?

Answer 19

• improved security data packets are not sent directly
• new systems can be attached directly to the central system
• transfer speeds are generally fast

Question 20

disadvantages of star topology

Answer 20

• extra hardware (hub / switch) required to be purchased
• if central system hub/switch fails the whole network is unusable

Question 21

what is a mesh topology?

Answer 21

where each computer system is connected to every other computer system

Question 22

what is a partial mesh?

Answer 22

where some nodes (printer or something) are only connected to every other node

Question 23

how does mesh topology work?

Answer 23

data packets are transferred to the destination address along the quickest path node, to node
if a pathway is broken it can take an alternative route

Question 24

advantages of mesh topology

Answer 24

• if one cable / system fails then data packets can take an alternative route
• withstand large amounts of data traffic
• new systems can be added to the network without disrupting the entire topology

Question 25

disadvantages of mesh topology

Answer 25

• large amount of cables expensive to install and maintain
• redundant cabling should be avoided (connecting systems that wont ever communicate)

Question 26

name some factors that affect the performance of a network

Answer 26

bandwidth
users at the same time
data collisions
interference (thick walls)
applications used
distance to travel
signal strength
amount of data to transfer
server / cpu performance