1.3.3 Networks

Question 1

Network

Answer 1

an interconnected set of devices

Question 2

network topology

Answer 2

actual architecture of a network / structure

Question 3

networks - positives

Answer 3

• allows sharing of data
• allows collaborative working
• allows communication
• allows sharing of resources eg. printers
• easy to backup to central server

Question 4

networks - drawbacks

Answer 4

• user can become dependent on the network
• efficiency of a network can be affect by barriers
• network manager required (costly)
• as traffic increases on a network, bandwidth decreases and performance falls
• difficult to secure network from security breaches

Question 5

protocols

Answer 5

set of rules which govern data transmission over a network

Question 6

TCP - transmission control protocol

Answer 6

used with IP to ensure error free transmission and packet switching

Question 7

IP- internet protocol

Answer 7

used to transfer all packets across the internet between routers

Question 8

NIC network interface card

Answer 8

receive and sends electrical signals in a network

Question 9

router

Answer 9

devices which are used to connect networks, they recieve data packets from one network and route it to another

Question 10

switches

Answer 10

devices used to connect devices on a network, use MAC address to send data to destination node

Question 11

MAC address

Answer 11

identifier permanently added to a device by the manufacture

Question 12

HUBs

Answer 12

connects nodes together by broadcasting a signal to all possible destinations

Question 13

WAP wireless access point

Answer 13

connects node to network wirelessly

Question 14

coaxial copper cable

Answer 14

older, slower, cheaper

Question 15

fibre optic cable

Answer 15

newer, faster and high capacity

Question 16

bus topology

Answer 16

nodes are connect to central communication channel.

each end of backbone is connected to a terminator

each node is passive and data is sent in one direction at a time only

Question 17

Bus topology - advantages

Answer 17

• cheap to set up
• devices can easily be added
• good for small networks

Question 18

Bus topology - disadvantages

Answer 18

• main cable is a single point of failure
• limited cable length
• performance degrades heavy use
• poor security

Question 19

star topology

Answer 19

where central node or hub provides a common connection point for all other nodes

Question 20

star topology - advantages

Answer 20

• easy to isolate problems
• good performance
• more secure as switch is used, data only sent to recipient

Question 21

star topology - disadvantages

Answer 21

-expensive to set up due to length of cable required
- central device is a point of failure

Question 22

ring topology

Answer 22

where node connect to two others to form a ring

Question 23

mesh topology

Answer 23

where ever node is connected to every other node

Question 24

client-server model

Answer 24

one device (client) requests services from another device (server)

Question 25

peer-to-peer model

Answer 25

all terminals have equal status and there is no powerful central server, each computer acts as both client and server

Question 26

advantages of client-server

Answer 26

- user IDs, password and access levels centrally controlled - backup is centralised and usually automated - no access to other users files

Question 27

disadvantage of client-server

Answer 27

- can be expensive to set up and manage - server is single point of failure

Question 28

advantages of peer-to-peer

Answer 28

- cheap to set up and maintain - easy sharing

Question 29

disadvantages of peer to peer

Answer 29

- no central backing up - slower performance - bad security

Question 30

what is client side processing

Answer 30

processes data via users device rather than using a server

Question 31

advantages of client side processing

Answer 31

- allows more interactivity by immediately responding to users action - removes potentially unnecessary processing from server

Question 32

disadvantages of client side processing

Answer 32

- not all browsers support script/code - dependent on performance of clients machine as processed by client

Question 33

what is a gateway

Answer 33

node on a network that serves as an entrance to another network

Question 34

what is a Port

Answer 34

software construct serving as a communication endpoint. Each has a number used by protocols to specify what data is being sent

Question 35

circuit switching

Answer 35

complete circuit or route between two nodes is established before transmission begins. Once route is established all data follows this route until transmission is complete.

Question 36

packet switching

Answer 36

- data to be transmitted is broken up into packets - each packet is labelled with address and packet number - packet is forwarded onto network and follows route - depending on network traffic each packet will take different routes - once it arrives to recipient, packets are reassembled

Question 37

Proxies

Answer 37

ensures there is no direct physical connection between a single user and a remote source.

Question 38

encryption

Answer 38

method of transforming data into encrypted way so it cannot be understood by unauthorized people, a key is used to decrypt

Question 39

trojan

Answer 39

software that misleads user of its true intent

Question 40

phishing

Answer 40

using email to manipulate a victim into visiting a fake website and giving away personal information