The Internet as The Biggest Distributed System and Platform for E-business

1. The Internet as The Biggest Distributed System and Platform for E-business Slide # 02 E-business (constructed by Dr. Hanh Pham)

2. The Internet and the World Wide Web • The Internet • Think hardware (“connected” computers/devices) • Originated with ARPANET (late 1960s) • The World Wide Web (WWW) (W3) • Think software (users communicating over the Internet via software applications) • Originated with Tim Berners-Lee and HTML, and took off with the first GUI browser, Mosaic E-business (constructed by Dr. Hanh Pham)

3. The Internet of Things • Devices can be connected to the Internet • Controlled remotely • Examples: sensors, switches, optical scanners • The Internet of things • Term used for these connected devices • Estimated size is nine billion • Projected to reach 35 billion by 2020 E-business (constructed by Dr. Hanh Pham)

4. The Internet = Network of Devices Networks of Computers (Computer Networks) • Topologies: E-business (constructed by Dr. Hanh Pham)

5. Local area network (LAN)= Network of computers located close together E-business (constructed by Dr. Hanh Pham)

6. Wide area networks (WANs)= Networks of computers connected over greater distances E-business (constructed by Dr. Hanh Pham)

7. E-business (constructed by Dr. Hanh Pham)

8. The Internet = Network of Devices • Architectures: E-business (constructed by Dr. Hanh Pham)

9. Network OSI Model E-business (constructed by Dr. Hanh Pham)

10. Internet Protocols • Protocol: collection of network data rules • Includes transmission rules • Computers must use same protocol • ARPANET: Network Control Protocol (NCP) • Proprietary architecture (closed architecture) • Manufacturer creates own protocol • Open architecture (Internet core) • Uses common protocol • Four key message-handling rules • Contributed to the Internet’s success E-business (constructed by Dr. Hanh Pham)

11. TCP/IP • Refers to the two pervasive protocols used today • Transmission Control Protocol (TCP) • Controls message or file disassembly into packets before Internet transmission • Controls packet reassembly into original formats at destinations • Internet Protocol (IP) • Specifies addressing details for each packet • Labels packet with origination and destination addresses E-business (constructed by Dr. Hanh Pham)

12. IP Addressing • Internet Protocol version 4 (IPv4) • Used since 1981 • IP address • 32-bit number identifying computers/devices • Base 2 (binary) number system • Computers use for internal calculations • Digit: 0 or a 1 (on or off condition) • Four billion different addresses (232 = 4,294,967,296) • Router breaks message into packets • Contains source and destination IP address E-business (constructed by Dr. Hanh Pham)

13. IP Addressing (cont’d.) • Internet Protocol version 6 (IPv6) • Replaces IPv4 • Addresses predicted to be exhausted in 2015 • IPv4 and IPv6 not directly compatible • IPv6 major advantages • Uses 128-bit number for addresses • Number of available addresses: 34 followed by 37 zeros • More complex notation system E-business (constructed by Dr. Hanh Pham)

14. Some Other Protocols • UDP (alternative of TCP for Transport Layer) is fast and can be used if there is a lot of data and you don’t mind losing a few bits • Simple Mail Transfer Protocol (SMTP) Post Office Protocol (POP) for Emails • FTP is a file transfer standard • TELNET provides a non-secure way to login to a remote computer • SSH can be thought of as a “secure telnet” E-business (constructed by Dr. Hanh Pham)

15. Some Other Protocols E-business (constructed by Dr. Hanh Pham)

16. Virtual Private Network (VPN) • Connection via public networks and protocols • Uses IP tunneling (encapsulation) system • Private passageway through public Internet • Secure transmission • Encapsulation • Encrypts packet content; places inside another packet • IP wrapper: outer packet • VPN software installed on both computers • “Virtual” since connection seems permanent • Actually a temporary connection

17. Virtual Private Network (VPN)

18. Intranets and Extranets • Intranet • An Internet within the boundaries of the organization • Interconnected private networks • Extranet • An Internet that extends beyond the organization and incorporates networks of outside entities • Technologies (public networks, private networks, or VPNs) • Independent of organizational boundaries

19. Client-Server Architectures • A “client” makes a request to a “server” • The server’s response may be • Compliance with the request • An error message indicating a problem • Example • A user’s browser requests a web page for display from a particular web site • The web server at that site sends the web page or an error message (like a page-not-found error) E-business (constructed by Dr. Hanh Pham)

20. Client-Server Architectures E-business (constructed by Dr. Hanh Pham)

21. Web Servers and Web Browsers • The term “server” may refer to a program or the machine it runs on • Current popular servers are Apache and Microsoft’s Internet Information Services (IIS) • Every browser is a program that can act as the client in a client-server relationship • Current popular browsers include Internet Explorer, Firefox, Chrome, Safari and Opera E-business (constructed by Dr. Hanh Pham)

22. Web Servers and Web Browsers E-business (constructed by Dr. Hanh Pham)

23. A Communication Protocol:HTTP for Web Browser and Server E-business (constructed by Dr. Hanh Pham)

24. Web Addresses • Every device connected to the Internet must have a unique IP address: • IPv4 is 32 bits: a.b.c.d with a, b, c, d in 0..255 • IPv6 is 128 bits, allowing for many more addresses • Computers understand IP addresses much better than humans, who prefer FQDNs • FQDN = Fully Qualified Domain Name • FQDN cs.smu.ca has IP address 140.184.133.99 • A Domain Name Server (DNS) translates between an IP address and the corresponding FQDN E-business (constructed by Dr. Hanh Pham)

25. URLs, URNs and URIs • A Uniform Resource Locator (URL) is the actual location of a resource on the web • A Uniform Resource Name (URN) has the same form as a URL but may not refer to an actual resource • The term Uniform Resource Identifier (URI) is a generalization of the above two terms and may refer to either one E-business (constructed by Dr. Hanh Pham)

26. E-business (constructed by Dr. Hanh Pham)

27. The Deep Web • Non-permanent Web pages can be created based on customized response to user’s search • Example: search for “online business” book on Amazon.com • Deep Web: information that is stored in databases and is accessible to users through Web interfaces • Potentially trillions of Web pages available using deep Web E-business (constructed by Dr. Hanh Pham)

28. Semantic Web • Goal: blending technologies and information into a next-generation Web • Web pages tagged (using XML) with meanings • Uses software agents (intelligent programs) • Read XML tags, determine meaning of words in their contexts • Resource description framework (RDF) • Set of XML syntax standards • Development of Semantic Web will take many years • Start with ontologies for specific subjects E-business (constructed by Dr. Hanh Pham)

29. References • searchcio.techtarget.com • tutorialspoint.com • Wikipedia • "Developing Distributed and E-commerce Applications", Darrel Ince, 2nd Edition, Pearson Addison Wesley • “Web Programming and Internet Technologies: An E-commerce Approach”, Porter Scobey, PawanLingras, Jones & Bartlett Publishers, 2013 • “Electronic Commerce”, 11th Edition, Cengage Learning, Gary Schneider, 2015 E-business (constructed by Dr. Hanh Pham)