Topic 4: Networks and the Effects of Using Them
1. Network Hardware & Cloud Services
Router – forwards data between different networks (e.g., LAN ↔ Internet); performs NAT, DHCP and basic firewall functions.
Advantages: connects multiple devices, provides security, supports Wi‑Fi.
Disadvantages: can be a single point of failure; performance limited by processing power.
Network Interface Card (NIC) – hardware that gives a device a unique MAC address and enables it to connect to a network (wired or wireless).
Hub – simple device that repeats incoming signals to all ports; no intelligence, creates a single collision domain.
Advantages: cheap, easy to set‑up.
Disadvantages: inefficient, security risk, limited to small networks.
Switch – connects multiple devices and forwards frames only to the intended recipient using MAC addresses.
Advantages: reduces collisions, improves speed, can create VLANs.
Disadvantages: more expensive than hubs, requires configuration for advanced features.
Wireless LAN (Wi‑Fi) – uses radio waves (2.4 GHz/5 GHz) to connect devices without cables; standards include IEEE 802.11a/b/g/n/ac/ax.
Advantages: mobility, easy expansion.
Disadvantages: interference, lower security if not encrypted (WPA2/3).
Bluetooth – short‑range (≤10 m) wireless technology for peripherals (headsets, keyboards) and IoT devices.
Advantages: low power, simple pairing.
Disadvantages: limited bandwidth, can be vulnerable to “blue‑jacking”.
Cloud Computing – delivery of computing resources (storage, processing, software) over the Internet.
Public cloud (e.g., Google Drive) – shared infrastructure, pay‑as‑you‑go.
Private cloud – dedicated resources for a single organisation, higher control.
Hybrid cloud – combination of public and private.
Advantages: scalability, reduced hardware costs, remote access.
Disadvantages: dependence on Internet connectivity, data‑security concerns.
2. Types of Networks
Network Type
Typical Scope
Key Characteristics
LAN (Local Area Network)
Single building or campus
High speed, low latency; usually Ethernet or Wi‑Fi.
WLAN (Wireless LAN)
Same as LAN but uses radio waves (Wi‑Fi)
Mobility, requires access points and WPA2/3 security.
WAN (Wide Area Network)
Geographically dispersed sites (city, country, world)
Public or leased lines, lower speed, higher latency.
Intranet
Organisation’s internal network
Restricted access, uses Internet protocols behind firewalls.
Extranet
Intranet plus limited external access for partners/customers
Secure gateways, often VPN‑based.
Internet
Global public network
Open standards, massive scale, requires robust security.
3. Network Security & e‑Safety
3.1 Passwords & Authentication
Strong passwords : ≥ 8 characters, mix of upper‑/lower‑case, numbers, symbols.
Authentication methods :
Biometric (fingerprint, facial recognition)
Smart‑card / token‑based
One‑time password (OTP) via SMS or authenticator app
Best practice : change regularly, avoid reuse, store in a password manager.
3.2 Anti‑malware & Protection Tools
Definition : software that detects, prevents and removes malicious code.
Common types : viruses, spyware, ransomware, trojans, adware.
Protection steps :
Keep OS and applications up‑to‑date.
Run regular full‑system scans.
Enable real‑time protection and a reputable firewall.
3.3 Firewalls & VPNs
Firewalls – filter incoming/outgoing traffic based on rules; can be hardware (router‑based) or software.
VPN (Virtual Private Network) – encrypts traffic between a device and a remote network, providing secure remote access.
3.4 Common Data‑Security Threats
Threat Typical Target Mitigation
Phishing / Smishing / Vishing Users’ login credentials Educate users, use email filters, enable 2FA.
Pharming Web traffic redirection Keep DNS servers secure, use anti‑pharming tools.
Hacking / Malware injection Servers, databases Patch software, use firewalls, intrusion detection.
Card fraud Payment systems Encrypt card data (TLS/SSL), comply with PCI‑DSS.
3.5 Privacy, Encryption & Legal Frameworks
Encryption : TLS/SSL for data‑in‑transit; AES‑256 for data‑at‑rest.
Legal/ethical : GDPR, Data Protection Act – personal data must be stored securely and used only for legitimate purposes.
Best practice : limit access, review permissions regularly, obtain consent before recording.
3.6 e‑Safety for Conferencing
Use meeting passwords and waiting rooms.
Share links only with intended participants.
Lock the meeting once all attendees have joined.
Disable “anyone can share” unless required.
Obtain explicit consent before recording or taking screenshots.
Avoid displaying confidential screens when the room is not locked.
4. Electronic Conferencing
4.1 Video‑Conferencing
Characteristics
Real‑time video + audio; typically ≥ 1 Mbps per participant.
Delivered via dedicated apps (Zoom, Teams, Google Meet) or web‑based clients.
Features: screen sharing, virtual backgrounds, recording, breakout rooms, chat.
Uses
Remote meetings, workshops, seminars.
Online education and distance learning.
Tele‑medicine consultations.
Virtual conferences, trade shows, product demos.
Advantages
Face‑to‑face interaction without travel.
Visual cues and live demonstrations.
Reduced travel costs and carbon footprint.
Sessions can be recorded for later review.
Disadvantages
High bandwidth requirement – excludes users with slow connections.
Technical issues: latency, dropped frames, echo.
Security risks if not password‑protected or encrypted.
Depends on reliable power and network at each endpoint.
4.2 Audio‑Conferencing
Characteristics
Voice‑only transmission; 30–100 kbps per call.
Can use PSTN (circuit‑switched) or VoIP (packet‑switched).
Features: mute, hold, call transfer, conference bridge, dial‑in numbers.
Uses
Business conference calls and board meetings.
Customer‑support hotlines.
Team collaboration where visual material is unnecessary.
Executive tele‑presence when only audio is required.
Advantages
Low bandwidth – works in most environments.
Generally lower latency than video.
Works on phones, tablets and computers.
Cheaper to implement and maintain.
Disadvantages
No visual cues – can cause misunderstandings.
Sharing visual information requires a separate tool.
Background noise or echo may affect clarity.
Recording or transcription often needs extra software.
4.3 Web‑Conferencing
Characteristics
Runs inside a web browser (HTML5, JavaScript, WebRTC).
Combines audio/video with collaborative tools: document sharing, whiteboard, polls, breakout rooms.
No client installation – click‑to‑join from desktop or mobile browsers.
Scalable from a few participants to thousands.
Uses
Live webinars, public lectures, virtual events.
Online classes, tutorials and blended learning.
Remote project work – screen sharing, co‑editing.
Corporate training and professional development.
Advantages
Easy access – no software download.
Integrated collaboration reduces the need for separate apps.
Cross‑platform (Windows, macOS, Linux, iOS, Android).
Can host large audiences with minimal extra cost.
Disadvantages
Performance depends on browser compatibility and device resources.
Security risks if settings are lax (e.g., “Zoombombing”).
When many participants share video, bandwidth rises to medium‑high.
Limited functionality offline or with very poor connectivity.
5. Comparison of Conferencing Types
Feature
Video‑Conferencing
Audio‑Conferencing
Web‑Conferencing
Bandwidth Requirement
High (≥ 1 Mbps per participant)
Low (30–100 kbps)
Medium (≈ 300–600 kbps; rises with video sharing)
Visual Interaction
Full video + screen share
None (audio only)
Video optional; screen share & whiteboard always available
Ease of Access
Client install or web app
Phone or soft‑phone client
Browser‑based – click‑to‑join
Typical Use Cases
Remote meetings, e‑learning, tele‑medicine
Business calls, support hotlines
Webinars, virtual classrooms, large‑scale events
Security Concerns
High – video streams, recordings, screen data
Moderate – voice data, dial‑in numbers
High – web‑based vulnerabilities, link sharing
e‑Safety Features
Passwords, waiting rooms, lock‑meeting, consent for recording
Call authentication, PIN protection
Link protection, participant authentication, role‑based permissions
6. Effects of Using IT
Micro‑processor‑controlled devices – smartphones, tablets, smart watches, IoT sensors, embedded systems in appliances. They enable automation, data collection and remote control.
Health problems :
Repetitive Strain Injury (RSI) from prolonged typing or mouse use.
Eye strain and headaches from screen glare or poor lighting.
Postural issues – slouching, neck pain.
Mitigation: regular breaks (20‑20‑20 rule), ergonomic furniture, proper lighting, posture awareness.
7. ICT Applications (Cambridge Syllabus Overview)
Application Area
Description
Typical Example
Communication
Exchange of information via email, instant messaging, video/web‑conferencing.
Zoom meeting, corporate email system.
Modelling
Creating digital representations of real‑world systems for analysis or prediction.
Spreadsheet financial model, simulation of traffic flow.
Controlled Systems
Hardware‑software systems that monitor and control processes.
Home automation (smart thermostat), industrial PLC.
School / Booking / Banking Systems
Database‑driven applications for managing records, appointments or transactions.
Student information system, online ticket booking, internet banking.
Medicine
Electronic health records, tele‑medicine, diagnostic imaging.
Electronic patient record (EPR) system.
Expert Systems
AI‑based programmes that mimic human expertise to solve problems.
Medical diagnosis assistant, troubleshooting wizard.
Retail
Point‑of‑sale systems, e‑commerce platforms, inventory management.
Online shop (Shopify), barcode scanning at checkout.
Recognition
Biometric or pattern‑recognition technologies.
Fingerprint login, facial‑recognition security.
Satellite
Use of satellite communication for navigation, broadcasting, data transfer.
GPS navigation, satellite TV.
8. Systems Development Life‑Cycle (SDLC)
Analysis – gather user requirements, define problem.
Design – create data flow diagrams, UI mock‑ups, choose hardware/software.
Development / Testing – write code, build prototypes, test for bugs.
Implementation – install system, train users, migrate data.
Documentation – user manuals, technical guides, maintenance procedures.
Evaluation – assess whether objectives are met, collect feedback, plan improvements.
9. Safety & Security
9.1 Physical Safety
Keep cables away from walkways to avoid tripping.
Use surge protectors; avoid over‑loading power sockets.
Do not touch electrical equipment with wet hands.
Ensure proper ventilation for high‑performance hardware.
Follow manufacturer instructions for battery charging and disposal.
9.2 Data‑Security Threats & Counter‑measures
Threat Impact Counter‑measure
Hacking / Malware Unauthorised access, data loss Firewalls, anti‑malware, regular patches.
Phishing / Smishing / Vishing Credential theft User education, email filters, 2FA.
Pharming Redirected traffic to fake sites Secure DNS, anti‑pharming tools.
Ransomware Data encryption, loss of access Back‑ups, least‑privilege accounts.
Card fraud Financial loss Encryption, tokenisation, PCI‑DSS compliance.
10. Audience & Copyright
Identify the intended audience (e.g., peers, teachers, customers) and adapt language, level of detail and visual style accordingly.
When using text, images, video or software in projects:
Check the licence – copyright, Creative Commons, public domain.
Give proper attribution (author, source, licence).
Do not copy large amounts of copyrighted material without permission.
Respect intellectual‑property policies of the school or organisation.
11. Communication Skills in ICT
11.1 Email & Internet Use
Use a clear subject line, professional greeting, concise body, and appropriate sign‑off.
Attach files in widely supported formats (PDF, DOCX, JPEG) and keep size reasonable.
Check URLs before clicking; verify the site’s security (HTTPS, padlock).
11.2 Common Protocols
HTTP / HTTPS – web page transfer; HTTPS adds encryption.
SMTP – sending email.
POP3 / IMAP – retrieving email.
FTP / SFTP – file transfer (SFTP adds encryption).
VoIP (SIP, RTP) – voice over IP.
11.3 Evaluating Information
Check the author’s credentials and the publishing organisation.
Look for bias, date of publication and citations.
Cross‑reference with at least two other reputable sources.
Consider the purpose – inform, persuade, sell – and assess relevance.
12. Key Take‑aways
Choose the appropriate conferencing type (video, audio, web) based on bandwidth, visual needs and ease of access.
Strong passwords, two‑factor authentication, firewalls and VPNs protect conference data and overall network traffic.
Anti‑malware, regular updates and user education guard against common security threats.
Understanding network hardware (router, NIC, hub, switch, Wi‑Fi, Bluetooth) and cloud services explains how data moves from source to destination.
Be aware of the physical and health effects of prolonged ICT use and apply ergonomic and break‑taking strategies.
Apply the SDLC stages when developing any ICT solution, and always consider the audience and copyright requirements.
Effective communication – clear email, knowledge of protocols and critical evaluation of information – underpins safe and successful ICT practice.
Suggested diagram: Typical video‑conferencing setup showing participants, cameras, microphones, routers/switches, firewall and the Internet backbone.