OCR GCSE Computer Science Computer systems (01), June 2025: Question 4

4 (a) 1 mark each to max 2 2 Mark any two correct

• Small geographical location // single building points as long as not

• No use of external infrastructure // All hardware will be owned/managed by youth centre contradicted.

• Dedicated hardware // The hardware is not shared/used by anyone else/any other business

• It is not connecting networks (like a WAN does)

4 (b) (i) 1 mark each to max 2 2 MP1 BOD each device is

• (Partial mesh) means all devices are connected to one or more devices // (Full mesh) means connected to other devices

all devices are connected to every other device // all devices are

• No need for central management / switch / device / node // All devices are equal // connected

Decentralised MP2 do not accept no

• Multiple routes/paths (between devices) central server

4 (b) (ii) 1 mark each to max 2 for drawback max 2 for benefit e.g. 4 1 mark for a point 1 for

11 expansion/reason/benefit.

Benefits:

• No purchase/cost of central switch / device Any of the MPs can be the

• … lower cost to install/maintain network // no need to setup / connect to the central device benefit/drawback and can

be the expansion as long

• More connections/paths between devices // alternate routes as they follow on.

• … no single point of failure // if a connection breaks can still connect

• … more robust structure Do not accept

faster/slower transmission

• More scalable // can have more devices/connections/nodes/computers speeds – dependent on

• … easier to add devices media and many other

factors.

• … can add / remove nodes without impacting other nodes/speed

MP3 and MP4 can be in a

• Decrease in latency

single statement e.g. ‘If

• … fewer collisions one connection breaks the

nodes can still connect

• Can be setup over a larger area // can provide a more stable connection through another route’

• … each device acts as repeater

Drawbacks:

• Large number of / more connections/wires

• … can involve redundant connections

• … this is impractical

• Reduced central management/control/oversight of the network/transmission

• … less control over transfer/security of the network

• Less secure BOD example less secure

• … more routes/points/devices for data interception/attack/unauthorised access

• Difficult to find an error

• … because of the multiple routes where an error could occur

• Mesh network uses more power

• … more nodes are involved in each transmission

4 (c) (i) 1 mark each to max 3 e.g. 3 MP1 is for easier to add

• Easier to add more devices/users 12 more devices to the

• Can have more devices/connections/users // more scalable network.

• … without cost of purchase/install additional wired connections MP2 is there can be more

• Devices are not fixed to one spot // devices can be moved // can connect from anywhere in connections/nodes/devices

(wireless) range than on a wired.

• …allowing people to use them where they are needed // can use where there is no physical ‘more devices can be

connection added easily’ is MP1 on its

• Reduces risk of (additional) trailing wires own.

• Less potential damage to equipment/wires

• Connect wider range / more types of device // by example e.g. mobile phones/tablets

• … that don’t have ports / wired connections // that only have wireless connections

• It allows a backup network if the wired network fails

• (Due to each node acting as a repeater in the mesh) the network will have a greater range

4 (c) (ii) 1 mark per bullet to max 2 for each factor 4 Allow reverse of each.

Factor How it affects the performance

Do not award references to

• More bandwidth = faster network/transmission BOD better Internet speed alone.

Bandwidth performance

• …because more data is transferred simultaneously/per second Points need to reference

Number of • More users = slower network/transmission BOD worse performance more/less data in correct

context.

users • …because more data is transferred simultaneously // more traffic //

accessing the the bandwidth is being shared/used // more bandwidth used // BOD

network at the more congestion / collisions

same time

4 (d) 1 mark each to max 5 e.g. 5 MP1 needs more than high

• Can be expensive for large amounts of data / long term / hosting // may be ongoing cost, it needs identification

subscription // no control over changing costs of ongoing, cost for hosting

• May be limited amount of storage etc.

• No control over security // Need to rely on provider for security

• May be hacked/stolen/intercepted/affected by a virus MP3 just poor/low security

• May lose (personal) data // May lose access to data is NE

• May go against DPA/legislation // Data may be misused (by provider)

• May not be clear where in the world the data is stored Accept data may be sold

as example of misuse.

• Limited/No control over access

• Company/cloud could go down 13

• No control over backup // May not have (automatic) backups …

• … data is not retrievable

• Need internet access // no internet access means no data

• … access speed depends on network/connection speed

• Concerns over ownership of the data

• Need to remember login details // may forget/lose login details

• Users may need training

4 (e) (i) 1 mark for router/modem 1

4 (e) (ii) 1 mark for each row. 4 Do not award rows with 2

ticks.

IP address Valid (✓) Invalid

(✓) Allow Xs in place of ticks in

✓ either/both columns.

192.154.21.2

258.0.0.3 ✓

56.1.2.66.1 ✓

✓

251.58.3.7

4 (e) (iii) 1 mark each to max 4 4 MP3 – award for the use of

• Browser checks cache for matching IP address the DNS converting URL to

• URL/domain is sent to DNS 14 IP

• DNS looks for URL/domain to find matching IP

• …in table/database/files/lists (of URL/domain and IPs) MP5 accept another/larger

• If not found the request is transferred to higher-level DNS for higher-level

• DNS returns IP address to computer/browser

• An error is returned/sent if the IP address cannot be found MP6 needs to be

computer/browser, do not

award user on its own.

4 (f) 1 mark for legislation Data Protection Act (2018) // DPA // GDPR // Data protection 4 If no legislation, wrong

legislation, unclear

1 mark each for steps to max 3 e.g. legislation still award up to

• Identify data protection officer max 3 marks for

• Keep data secure/safe (from unauthorised access) description of DPA.

• ... by example // installing firewall // usernames and passwords // access rights // physical

security // encrypt Accept answers listing

• Do not share/sell (without consent) what needs to be done e.g.

• Don’t store without consent data must be up-to-date

• Only keep relevant data (without the specific step

• … do not collect data from users that is not required that will be followed to do

this)?

• Do not store the data for longer than needed

• Make sure the data remains accurate / up-to-date

MP2 is stopping

• Only use for purpose collected // Data must not be misused unauthorised access.

• … state purpose for collection MP4 is the company

• Do not store/share with countries with lower levels of protection actively giving the data

• Change/delete data when requested … willingly to someone else.

• … permanently/securely

• Provide data for users when they request to see it

• Notify individuals of data breaches

• Must use data lawfully/fairly

• Staff need to be trained in principles