BTEC Level 3 Unit 19 Computer Networking Assignment Answer Guide

This answer guide covers Unit 19 Computer Networking in the Pearson BTEC Level 3 National Extended Diploma in Computing, focusing on Assignment 1 of 2, “Investigating Computer Networks” (learning aim A). It explains A.P1, A.P2, A.M1 and A.D1, shows how to structure the customer-facing web page the brief asks for, and gives model paragraphs plus a worked subnetting and data-transfer example.

What the Unit 19 assignment asks you to do

You are a junior network technician at a company that designs and installs networks. Your manager wants a page for the company website that gives customers technical information before they choose a network. The page must do two things:

1. Network models and types: explain and evaluate peer-to-peer, client/server and thin-client models, explain why different network types and topologies are needed, and cover current trends such as bring your own device (BYOD) and cloud computing. The brief asks for balanced points on ease of use, set-up, performance and suitability, with examples of benefits and drawbacks for different uses.
2. Network components: explain the characteristics and analyse the functions of the components used in LANs, WANs and wireless networks, show why protocols and standards matter, and give examples of how data moves within and between networks.

Your evidence is a web page (or set of pages), so write for a customer: clear headings, diagrams and short paragraphs, but with technical accuracy.

Learning aims for Unit 19

Pass, Merit and Distinction criteria explained

How to answer A.P1 and A.D1: network types and models

Organise this section around client needs rather than definitions. A definition earns little on its own; explaining why a client would choose it earns the marks.

• Types: PAN, LAN, WLAN, MAN and WAN — scale, ownership and typical use.
• Models: peer-to-peer (no dedicated server, cheap, hard to manage beyond a few devices), client/server (central storage, authentication and backup, but higher cost and a single point of failure unless made resilient), thin client (processing and storage on the server, cheap and easy-to-manage endpoints, but dependent on the server and the network).
• Topologies: star, bus, ring, mesh and hybrid; explain why modern Ethernet LANs are physically star or extended star, and why WAN links between sites often use partial mesh for resilience.
• Trends: BYOD (convenience and cost against security and support issues, usually handled with a guest network or mobile device management) and cloud computing (scalability and remote access against reliance on internet connectivity and ongoing subscription costs).

How to answer A.P2 and A.M1: network components

Use a table for P2, then move into prose for M1 to show how the components work together.

• End devices and NICs: each has a MAC address; the NIC converts data into signals for the medium.
• Switch: forwards frames within a LAN using MAC address tables (layer 2).
• Router: forwards packets between networks using IP addresses and routing tables (layer 3); the default gateway for a LAN.
• Wireless access point: connects Wi-Fi devices to the wired LAN using IEEE 802.11 standards.
• Firewall: filters traffic by rules to protect the network.
• Media: twisted-pair copper (Cat 5e/Cat 6), fibre optic for long or high-speed links, and wireless.
• Servers and services: DHCP issues IP addresses, DNS turns names into IP addresses, file and print servers, authentication.
• Protocols and standards: TCP/IP, Ethernet (IEEE 802.3), Wi-Fi (IEEE 802.11), HTTP/HTTPS, and why common standards let equipment from different makers work together.

Suggested structure for the web page

1. Introduction: who the company is and what the page helps customers decide.
2. Network types: PAN to WAN, each with one real-world example of who uses it (A.P1).
3. Network models and topologies: peer-to-peer, client/server and thin client, with a labelled diagram for each and the reasons a customer would choose it (A.P1).
4. Current trends: BYOD and cloud computing, with benefits and drawbacks for small and large organisations.
5. Components table: device or medium, characteristics, function and layer (A.P2).
6. How data travels: one example inside a LAN and one between sites over a WAN, showing which components and protocols are involved at each step (A.M1).
7. Which model suits you? client scenarios, a comparison table and justified recommendations (A.D1).
8. References: standards bodies, manufacturer documentation and textbooks you used.

Worked example: subnetting and transfer time

1. Splitting a network for a client. A school has the address block 192.168.10.0/24 and wants four separate subnets: staff, students, admin and Wi-Fi guests.

• Four subnets need 2 extra network bits (2² = 4), so the prefix becomes /24 + 2 = /26.
• Subnet mask: 255.255.255.192.
• Each subnet has 2⁶ = 64 addresses; minus the network and broadcast addresses gives 62 usable hosts.
• Subnets: 192.168.10.0/26 (hosts .1–.62, broadcast .63); 192.168.10.64/26 (.65–.126, broadcast .127); 192.168.10.128/26 (.129–.190, broadcast .191); 192.168.10.192/26 (.193–.254, broadcast .255).

If the student subnet needs 100 devices, /26 is too small; a /25 (126 hosts) would be needed for that subnet, which shows why the client’s requirements must be checked before the design is fixed.

2. Why bandwidth matters. A 2 GB video file is 2 × 8 × 1,000,000,000 = 16,000,000,000 bits (using decimal units). Over a 100 Mbps link: 16,000,000,000 ÷ 100,000,000 = 160 seconds. Over a 1 Gbps link: 16 seconds. Real transfers take longer because of protocol overhead and other traffic, but the comparison is a clear way to justify a faster switch or uplink to a customer.

Common mistakes that cost marks

• Writing a list of definitions with no explanation of why different clients need different types and models.
• Confusing a switch and a router, or a hub and a switch.
• Leaving out BYOD and cloud computing, which the brief asks for.
• One-sided points: the brief wants benefits and drawbacks for ease of use, set-up, performance and suitability.
• No example of data travelling within and between networks, which weakens A.M1.
• Copied diagrams with no labels or explanation.
• Forgetting the audience: the page is for customers, so jargon needs explaining.

How to move from Merit to Distinction

A.D1 asks you to evaluate models against different client requirements. Set out three or four short client scenarios — for example a home office, a small shop with card payments, a school, and a company with two sites — and judge each model against cost, security, ease of management, performance and scalability. Reach a recommendation for each client and justify it, including what would change the recommendation (growth, remote working, budget). A comparison table followed by reasoned conclusions works well on a web page.

FAQs

Does the Unit 19 assignment have to be a website?

The linked brief asks for a web page for customers. Follow your own brief — the format matters less than meeting each criterion clearly.

How much do I need to say about the OSI model?

Enough to place each component at the right layer and explain how data is passed down and up the layers. A labelled diagram with a short explanation usually works.

What is the difference between A.P1 and A.D1?

A.P1 explains why different types and models exist. A.D1 judges how well each model fits specific client requirements and reaches a recommendation.

Should I include subnetting in Assignment 1?

It is not required by the A criteria, but a short example supports your explanation of how routers and addressing move data between networks, and it prepares you for the design work in Assignment 2.

Need one-to-one support from a subject specialist? Our BTEC Level 3 assignment help service covers planning, feedback on drafts and referencing.

For other IT units, see our BTEC Level 3 Unit 1 Information Technology Systems answer guide and the HND Computing security answer guide. If you want a tutor to check your work against the criteria, you can get expert help with your BTEC assignment.