PAST PAPER GENERAL CORRECTIONS

define pixel

smallest unit of an image

describe what is meant by a mesh topology (4)

• partial mesh - all devices connected to one or more devices

• full mesh - all devices connected to every other device

• no central management

• multiple routes between devices

benefits of mesh topology over star (4)

• lower cost - no need to maintain switch

• more connections - no single point of failure, more robust

• scalable - easier to add devices

• decrease in latency - fewer collisions

drawbacks of mesh topology over star (4)

• more connections - redundancy, impractical

• no central management - less control of security

• less secure - more points for interception

• more power - more nodes in each transition

drawbacks of cloud storage (10)

• expensive subscription costs

• limited storage

• no control over security and access

• hacked

• lose personal data

• provider goes against DPA

• no backups - data unretrievable

• need internet access

• access speed depends on network

• need to remember login details

what is needed to allow a LAN to connect to the internet

router/modem

how is a URL converted into an IP address? (5)

• browser checks cache for IP address

• domain name sent to DNS

• DNS looks for domain to find matching IP address in the list

• if not found, request transferred to higher level DNS

• DNS returns IP address to browser

describe the benefits to the airport of having wired connections (4)

• consistent bandwidth = reduce delays at check in

• no interception = personal data secure

• no interference = quick transmission of flight status

• long range transmission = large terminals

benefits of star topology over mesh (4)

• easy to add new nodes

• centralised management of network

• faster data transmission

• if one device breaks the rest of the network is unaffected

drawbacks of star topology over mesh (2)

• if the switch fails the whole network fails

• cost of switch

explain why the number of devices using the network at the same time can affect the performance of the network (4)

• less data can be transmitted at the same time

• more devices means more data is transmitted at the same time

• bandwidth is split between devices

• less bandwidth for each device

factors that affect the performance of a network (4)

• number of devices

• bandwidth

• interference

• transmission medium

what are the range of values for a valid ipv4 address

0-255

explain why ethernet is a standard (3)

• ethernet is used by all manufacturers

• allows compatibility with other devices

• ethernet has a high bandwidth

tasks carried out by a router (4)

• receives packets

• sends packets

• identifies the most efficient path to the destination

• converts packets from one protocol to another

describe how an analogue sound wave is converted into a digital form (5)

• sound wave is sampled

• amplitude is measured

• at set intervals

• measurements are stored as a binary number

• each binary number is stored sequentially

why does a TV need secondary storage (3)

• store recorded shows

• once turned off

• permanently