1.3.3 Networks Exam Questions
Paper 1 · Computer Systems · 15 past paper questions · 52 marks
Exam questions for 1.3.3 Networks
15 OCR past paper questions (52 marks) with mark schemes
Answer each question, reveal the mark scheme, then award yourself marks. Scores and answers are saved in this browser so you can see which topics need more work.
Download Questions & Mark Scheme (PDF)Past paper questions
- Question 1H446/01 · June 20242 marks
Explain what a protocol is and why they are important in network communications.
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A set of rules for communication/transmission/transfer of data between devices The sending system has no direct control over the way the receiving system responds / Allows standardisation / Protocols allow for data to be exchanged in a predictable way (2 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 2 - Question 2H446/01 · June 20246 marks
Describe three different pieces of networking hardware in a client-server network apart from the clients and servers themselves.
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Router - Connects networks together, assigns IP address to devices, examines data packets and forwards them Switch - Connects multiple wired devices to the network, receives data and forwards it to intended recipient, routes based on MAC addresses Hub - Receives data from a device and broadcasts it to all devices connected Wireless Access Point (WAP) - Allows wireless devices to communicate, sends/receives radio waves Gateway - Connects different types of network, translates protocols from one network to another Bridge - Connects different network segments Repeater - Receives a signal and retransmits it Network Interface Card (NIC) - Gives each device a MAC address, allows computer to interface with network (6 marks - 2 marks per hardware: 1 for name, 1 for description, max 6)Mark yourself: how many marks did you get?/ 6 - Question 3H446/01 · June 20233 marks
Give three advantages to the business of connecting computers together in a LAN.
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Share hardware (e.g. printers) Share files Share Internet connection Centralised security Log on/access files from any machine on the LAN Central maintenance/backup/storage Central installation/update of programs Can monitor user activity Can control access levels (3 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 3 - Question 4H446/013 marks
Explain why protocol layering is used.
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To apply protocols in order / one after the other To provide independence of layers // Layers can be modified without affecting others Hides details from previous or next layer(s) // is an abstraction Each layer is well defined / does a specific job Breaks tasks down into manageable units Improved troubleshooting (easier identification of layer that causes issue) Allows for standards for individual tasks/layers to be developed (3 marks - 1 per bullet, max 3)Mark yourself: how many marks did you get?/ 3 - Question 5H446/012 marks
Describe one difference between packet switching and circuit switching.
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In circuit switching dedicated hardware resources are used for each connection / In packet switching hardware is used for multiple connections In circuit switching data is sent along one route/stream / In packet switching packets may be sent along multiple routes Circuit switching is less secure / Packet switching data is more secure (2 marks - mark in pairs)Mark yourself: how many marks did you get?/ 2 - Question 6H446/012 marks
Explain why packet switching is more suitable for a computer network than circuit switching.
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Computer networks involve multiple connections happening concurrently / In packet switching hardware is not tied up with each unique connection Computers pass vast amounts of data which may encounter transmission errors / Packet switching means only resending individual packets instead of whole data stream Packet switching means any network hardware failures can be mitigated by routing around it (2 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 2 - Question 7H446/019 marks
Discuss how Zac could set up a peer-to-peer network and a client-server network. You should refer to: how the computers in each type are connected, the benefits of each type, the drawbacks of each type, the suitability of each type.
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Levels of response question (9 marks) AO1 P2P: Each computer can act independently, responsible for its own security/login, maintains/shares own hardware, no resources not shared by peer, simple to add machines, little administration needed. Client Server: All network functionality provided by servers, server machine designed to never be powered down, login/security handled centrally, shared storage/resources managed by server. AO2 P2P: Offers flexibility in adding staff, suitable for small company, may struggle to pay for IT admin skills needed for client server. Client Server: Accountancy firm has sensitive customer data, allows stronger centralised security, multiple staff can work collaboratively with shared storage. AO3: Candidates can conclude either method, but must have clear line of reasoning. P2P good for small/flexible setups, Client-Server better for security/collaboration.Mark yourself: how many marks did you get?/ 9 - Question 8H446/01 · June 20225 marks
Explain what happens at the application layer of the TCP/IP stack when using an encrypted messaging program.
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Protocol to be used is decided based on the application (e.g. HTTPS) Adds encryption Passes on to transport layer to send Gets data from transport layer when receiving Unpacks message ready for display Decrypts message (5 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 5 - Question 9H446/01 · June 20222 marks
Explain what happens at the link layer of the TCP/IP stack.
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Receives (layered) data from internet layer to send / Passes (layered) data back up to internet layer when receiving MAC addresses are added to the packet Passes and receives data across wireless network (2 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 2 - Question 10H446/012 marks
Complete the table to show the four layers of the TCP/IP stack.
TCP/IP stack Application Link Show mark scheme
Transport, Network/Internet (2 marks - 1 per layer)Mark yourself: how many marks did you get?/ 2 - Question 11H446/01 · June 20203 marks
Explain what is meant by the term 'TCP/IP stack'.
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Stands for Transmission Control Protocol / Internet Protocol Protocol(s)/set of rules for communicating across a network/the internet Each protocol belongs to a different layer: Application, Transport, Internet, Link (3 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 3 - Question 12H446/01 · June 20203 marks
Explain the purpose of a network switch.
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Joins computers/devices together on a LAN Receives packets/data Recipient's address is given in packet header/it uses the MAC address Send packets/data out the correct port /to the specific computer device (3 marks - 1 per bullet)Mark yourself: how many marks did you get?/ 3 - Question 13H446/014 marks
Explain how the Domain Name System (DNS) plays a role in websites being loaded.
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DNS is used to resolve IP corresponding to URL Request sent to DNS resolver Resolver checks its cache and if it doesn't hold the URL, it passes it to the TLD Name server Authoritative Name Server returns the IP address IP address is returned back up to the requesting client (4 marks - 1 per bullet, max 4)Mark yourself: how many marks did you get?/ 4 - Question 14H446/01 · June 20182 marks
Describe what is meant by the term 'WAN'.
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Wide Area Network Collection of connected computers/devices over a large geographical area Often using 3rd party communications channels (2 marks - 1 per bullet, max 2)Mark yourself: how many marks did you get?/ 2 - Question 15H446/01 · June 20184 marks
State the name of the four layers of the TCP/IP stack.
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Application Transport Internet Network Interface/Link/Physical (4 marks - 1 per layer)Mark yourself: how many marks did you get?/ 4
Key Exam Tips for 1.3.3
- 1Network types: PAN (personal), LAN (building), WAN (global/Internet)
- 2Protocols: HTTP/HTTPS (web), TCP (reliable), IP (addressing), DNS (domain→IP), SMTP/POP3/IMAP (email)
- 3TCP/IP stack: Application → Transport → Network → Link
- 4Hardware: NIC (MAC address), Switch (LAN), Router (between networks)
- 5Packet switching: No dedicated path, resilient; Circuit switching: Dedicated path, consistent
General Exam Advice
- •Practice answering questions under timed conditions
- •Check your answers against the mark scheme carefully
- •Focus on understanding the marking points, not just memorising answers
- •Review past paper questions from multiple years to spot patterns