AQA A-Level Computer Science Paper 2, June 2025: Question 5

Mark scheme

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Qu Pt Marking guidance

marks

05 Marks are AO2 (analyse) 3

Large number of users / devices (to be managed);

Not possible to trust all users // some users may not be trustworthy;

Confidential data is likely to be (A. will be) stored;

A. examples of confidential data in the context of a school

Complex management of access rights required // different (groups of) users will

require different access privileges // the school/technicians will be able to control

which resources are shared // prevent students sharing files directly from their

computers // centralised management of security // management of Internet

access // management of/accounting for printing resources;

A. other examples in context of a school

NE. stop users accessing others users’ files

All resources/files/data can/will be stored centrally // if a device is not working the

data resources/files/data will be accessible from another device // if a device is not

working data will not be lost (as stored on server) // easier for files to be

shared/distributed (in a controlled way);

Data will be available at all times // on a peer-to-peer network data would only be

available when the device it is stored on is turned on;

Server can be optimised for required tasks / managing files / accessing files;

Data can be backup up centrally // it is easier to backup as the data is on a server;

NE. easier to backup

Centralised/remote installation/updating of software possible;

Accept points made in reverse, ie as relevant limitations of peer-to-peer

systems instead of reasons to use a client-server system.

Max 3

How to answer it

Client-Server vs Peer-to-Peer Networks in a School

📋 What this question tests

This question assesses your ability to apply network architecture theory to a real-world scenario (AO2 - Application):

Understanding structural differences between Client-Server and Peer-to-Peer (P2P) architectures.
Evaluating operational needs of large organisations: user management, security tiers, access rights, and data integrity.
Contextual reasoning: why peer equality fails in environments with diverse trust levels (students vs teachers).

Question 05 • [3 Marks]

Explain why a client-server network would be more suitable for use in a school than a peer-to-peer network.

💡 Key Knowledge

Client-Server: Centralised server provides services, stores files, manages security credentials, and distributes resources to client machines.
Peer-to-Peer (P2P): All nodes have equal status with no central controller. Each computer acts as both client and server, storing its own files and settings.
School Context Demands:
- High volume of users & workstations.
- Confidential records (grades, medical, Safeguarding).
- Users cannot be implicitly trusted (students vs staff).
- Roaming logins (students work across different classrooms).

✅ Mark Scheme Points (Any 3)

Centralised Access Control / Security: Network admins can enforce user-level permissions so students cannot access confidential staff records or system files.
Centralised Storage / Roaming Profiles: Files are stored centrally; if a classroom PC breaks, work is not lost and can be accessed from any other machine.
Centralised Backups: Technicians can back up all network data from the central server at once rather than having to back up hundreds of individual PCs.
Central Software / Updates Deployment: Software and security patches can be installed remotely across all machines simultaneously.
High Device & User Scalability: Manages large numbers of computers and handles untrusted users effectively.
Controlled Resource Management: Central management of Internet filtering, print quotas, and hardware resource allocation.

🧠 Exam Technique & Strategy

Always link back to the school context: Don't just list textbook features of client-server networks. Mention students, teachers, classroom PCs, or sensitive school data.
State the mechanism, not just the benefit: Instead of saying "it's easier to manage", write "network administrators can manage access permissions from a central server".
Reverse arguments are accepted: You can score marks by pointing out P2P flaws (e.g. "In a P2P network, if a student turns off a machine hosting a file, no one else can access it").

❌ Common Errors & Lost Marks

NE "It is easier to backup": You must specify that data is backed up centrally from the server rather than machine-by-machine.
NE "Stops users accessing other users' files": Too vague. You must mention centralised access rights, user privileges, or authenticating different user groups.
Confusing Internet with Network Architecture: Saying "P2P has worse Wi-Fi" or "Client-server makes the internet faster". Network topology/architecture does not dictate broadband speed.
Forgetting to make 3 distinct points: Mentioning both "passwords" and "permissions" often collapses into a single security mark unless clearly separated into distinct concepts.

Exemplar 3-Mark Answer:
"A client-server network allows access rights and user permissions to be managed centrally, ensuring students cannot access confidential staff or school records (Mark 1). Furthermore, files are stored on a central server, allowing students and staff to access their work from any computer across the school rather than being tied to one machine (Mark 2). Finally, all files and data can be backed up centrally from the server, eliminating the need to perform separate backups on hundreds of individual workstations (Mark 3)."

Topics

4.9 Fundamentals of communication and networking · 4.9.2 Networking