INSY5111 - Lecture Unit 5 Notes

The Internet, Intranets, and Extranets

Theme 1: The World Wide Web (WWW)

Learning Objectives:
  • Describe the makeup of the Internet and the World Wide Web.
  • Discuss navigational tools, search engines, and directories.
  • Describe common Internet services.
  • Summarize widely used Web applications.
LO1: Introduction to the Internet
  • The Internet is described as a network of networks. It's a vast global system of interconnected computer networks.
  • The Internet is decentralized, meaning there is no single entity that controls the entire system. This allows for resilience, scalability, and collaboration.
Evolution of the Internet
  • Created in 1969.
  • Originated from the Advanced Research Projects Agency Network (ARPANET).
  • ARPANET was a U.S. military-funded initiative designed to enable communication between research institutions, which later evolved into the modern Internet.
LO1: Internet Infrastructure
  • Internet Backbone
    • The Internet’s foundation network.
    • Made up of high-bandwidth capable fibre-optic cables and interconnected commercial, academic, government, and high-capacity data routers.
    • It is the foundation for all other networks.
  • Network Access Points (NAPs)
    • NAPs connect LANs to the Internet backbone.
    • Crucial connection points that allow smaller regional networks, including ISPs (Internet Service Providers), to connect to the Internet backbone.
    • NAPs ensure that different networks can communicate with one another by providing infrastructure for traffic exchange.
LO1: The World Wide Web (Web)
  • Developed by Tim Berners-Lee in 1989.
  • Uses hypermedia: text, images, audio, video, etc.
  • Requires: PC and modem, ISP account, cabling, browser, TCP/IP, and email client.
LO1: Domain Name System (DNS)
  • DNS is an essential component of the Internet.
  • It translates human-readable domain names (e.g., www.google.com) into machine-readable IP addresses (e.g., 142.250.72.206).
  • Makes it easier to remember addresses.
  • How it works:
    1. User enters a domain name into a web browser.
    2. The DNS resolver contacts a DNS server to find the matching IP address.
    3. If the DNS server doesn’t have the information, it queries other servers until it locates the correct address.
    4. Once found, the browser uses this IP address to connect to the website's server.
LO1: Domain Name System (DNS) - URL Structure
  • A Web address (URL) is made up of five parts and must be typed correctly:
    1. HyperText Transfer/Transport Protocol (http)
    2. World Wide Web (www)
    3. Name of the server
    4. Type of site (generally consisting of a second-level/category domain and a Top-level domain (TLD)
Internet Connections
  • Connecting to the Internet is not a one-size-fits-all.
  • Popular methods include Dial-up, Cable Modems, Digital Subscriber Lines (DSL), T1/T3 Lines.
  • DSL Types:
    • Symmetric DSL: same data transmission rate is maintained to and from the phone network.
    • Asymmetric DSL (ADSL): has a lower transmission rate to the phone network (lower upload) than from the phone network (higher download).
    • Very High-Speed DSL (VDSL): very high-speed transmission rate to and from the phone network over short distances.
  • Organisations often use T1 or T3 lines.
  • T1 and T3 lines are provided by telephone companies and can transport the equivalent of 24 conventional telephone lines using only two pairs of copper wires.

LO2: Navigational Tools, Search Engines & Directories

Tools to find information are divided into three categories: navigational tools, search engines, and directories.

  • Navigational tools:
    • Graphical Web browsers: Chrome, Safari, Firefox, Edge
    • Features: History, bookmarks, tabs
  • Search Engines:
    • Google, Bing, Yahoo
    • Operate on a three-step process: Crawling, Indexing, Searching
  • Directories
    • Automated (by bots)
    • Human-powered (manual submission)

LO3: Common Internet Services

  • Email: Web-based (Gmail), Client-based (Outlook)
  • Newsgroups/Discussion Groups: Topic-based communities
  • Instant Messaging: WhatsApp, Messenger
  • Internet Telephony (VoIP): Skype, Zoom, WhatsApp voice
LO4: Web Applications in Industries
  • Tourism: Online booking
  • Education: LMS, virtual classes
  • Publishing & Real Estate: Online catalogs, listings
  • Employment: Job portals
  • Finance: Online banking
  • Healthcare: eHealth records
  • Politics: Campaign tools, fundraising

Theme 2: Intranets, Extranets, and WEB 2.0 and 3.0 eras

Learning Objectives:
  • Explain the purpose of intranets.
  • Explain the purpose of extranets.
  • Summarise new trends in the Web 2.0 and 3.0 eras.
LO5: Intranets
  • What are Intranets?
    • Private, internal communication systems that use standard internet technologies (such as browsers, servers, and network protocols) to facilitate communication and information sharing within an organisation.
  • Purpose?
    • Improve internal communication and collaboration.
    • Provide a central location for company policies, forms, calendars, etc.
    • Streamline access to business tools and databases.
  • Common features
    • Employee directories and contact info
    • Document repositories and templates
    • Internal messaging boards and newsfeeds
    • Training materials and HR self-service tools
    • Department-specific subpages or workspaces
  • Access control
    • Only authorised personnel (employees) can access the intranet.
    • Often secured via login credentials or internal network restrictions.
LO5: Benefits of Intranets
  • Ease of adoption
  • Cost-effective communication
  • Universal access via web browsers
  • Better document control & updates
  • Intuitive information access for mobile workers
LO6: Extranets
  • Connects intranets of business partners securely.
  • Uses VPNs for privacy.
  • Supports B2B collaboration.
  • Examples:
    • FedEx tracking
    • Supplier portals (e.g., Toshiba dealers)
  • Advantages:
    • Improved Co-ordination
    • Instant feedback
    • Customer satisfaction
    • Cost reduction
    • Expedited Communication
LO7: Web 2.0 and Web 3.0
  • Three generations of Web
    1. Web 1.0 → static content
    2. Web 2.0 → dynamic content
    3. Web 3.0 → Semantic Web
  • Web 2.0:
    • Blogs, Wikis, Social Media, Podcasts, RSS feeds, the Internet2 (I2)
    • Interactive and user-driven
  • Web 3.0:
    • Semantic Web, AI, 3D graphics, personalisation
    • Intelligent search and tailored content
The Internet of Everything (IoE)
  • Connects people, processes, data, and things.
  • IoT:
    • Smart devices (fridges, watches, sensors)
  • Technologies:
    • RFID
    • Wi-Fi
    • Bluetooth
    • QR Codes
Conclusion

Web 2.0/3.0 and IoE are the future of digital interactivity.

  • Internet → infrastructure
  • Web → content platform
  • Services and applications drive value
  • Intranets and extranets → secure organisational tools