1. Telecommunications, the Internet, Intranets, and Extranets
Chapter 4
Fundamentals of Information Systems, Second Edition

2. Fundamentals of Information Systems, Second Edition
Learning Objectives
Define the term telecommunications and identify and describe the function of the components of a telecommunications system.
Identify and briefly describe three basic data processing strategies, including their advantages and disadvantages.
Fundamentals of Information Systems, Second Edition

3. Fundamentals of Information Systems, Second Edition
Learning Objectives
Briefly describe how the Internet works, including alternatives for connecting to it and the role of Internet service providers.
Identify and briefly describe common Internet services.
Fundamentals of Information Systems, Second Edition

4. Fundamentals of Information Systems, Second Edition
Learning Objectives
Describe the World Wide Web and the way it works, including the use of Web browsers, search engines, Java, and other Web tools.
Define the terms intranet and extranet and discuss how organizations are using them.
Identify several control and management issues associated with the use of networks.
Fundamentals of Information Systems, Second Edition

5. Fundamentals of Information Systems, Second Edition
Telecommunication
Electronic transmission of signals for communications
Telecommunications device is a hardware component that allows electronic communication to occur
Telecommunications medium carries an electronic signal and interfaces between a sending device and a receiving device
Fundamentals of Information Systems, Second Edition

6. Elements of a Telecommunications System
Fundamentals of Information Systems, Second Edition

7. Fundamentals of Information Systems, Second Edition
Media Types (1)
Twisted-pair wire cable: Twisted pairs of copper wire
Used in telephone service
Slow transmission
Coaxial cable: Conductor wire is insulated
Faster than twisted-pair
Fiber-optic cable: Thin strands of glass bound together
Uses light beams
Faster than coaxial cable
Fundamentals of Information Systems, Second Edition

8. Fundamentals of Information Systems, Second Edition
Media Types (2)
Microwave transmission: High-frequency radio signal
Must have unobstructed line of sight between sender and receiver
Possible to intervene
Cellular transmission: Divide area into cells
Each cell has a mobile telephone subscriber unit
Infrared transmission: Signals as light waves
Fundamentals of Information Systems, Second Edition

9. Common Wiring and Cabling Types
Fundamentals of Information Systems, Second Edition

10. Common Telecommunications Devices
Modem: Translates data from digital form into analog form (for ordinary phones) and back
MOdulation and DEModulation
Fax modem: Facsimile device but also a modem
Multiplexer: Allow several signals to be transmitted over the same line
PBX: Manages both voice and data transfer
Switching equipment routes phone calls and messages within the building
Fundamentals of Information Systems, Second Edition

11. Fundamentals of Information Systems, Second Edition
Carriers and Services
Common carriers: Turk Telecom, AT&T
Switched lines
Use switching equipment to connect one phone to another
Switch: Special purpose circuit that directs messages in certain directions
Digital subscriber lines (DSL)
Use existing lines to transmit signals over 500Kbps
Faster Internet access
Fundamentals of Information Systems, Second Edition

12. Costs, Advantages, and Disadvantages of Several Line and Service Types
Line/Service
Speed
Cost per month
Advantages
Disadvantages
Standard phone line
56Kbps
$10-40
Broadly available
Too slow
ISDN
64-128Kbps
$50-150
Faster
Not available everywhere
DSL
500Kbps-1.5Mbps
$20-120
Use standard line
Expensive; not available ew.
Cable modem
Use existing cable “” T1
1.544 Mbps $
FAST; used by corporations
EXPENSIVE
Satellite
60-800Kps
$30-120
Instead of cable or DSL
Expensive installation
Fundamentals of Information Systems, Second Edition

13. Networks and Distributed Processing
Computer network - communications media, devices, and software needed to connect two or more computer systems.
Centralized processing - processing occurs in a single location or facility.
Decentralized processing - processing devices are placed at various locations.
Distributed processing - computers are placed at remote locations but are connected to each other via telecommunications devices.
Fundamentals of Information Systems, Second Edition

14. Terminal-to-Host Connection
Host computer has the data and the processing power
Dumb terminal contacts host computer for jobs
Fundamentals of Information Systems, Second Edition

15. File Server Connection
The application and database reside in host computer.
Files transferred as a whole and processed by the user
Fundamentals of Information Systems, Second Edition

16. Client/Server Connection
Servers have special functionalities (database server, program execution, etc.)
Clients request services from servers
Clients process service results
Fundamentals of Information Systems, Second Edition

17. Fundamentals of Information Systems, Second Edition
Network Types
Local area network (LAN)
Same geographic area
Wired into office buildings (unshielded twisted-pair)
Wide area network (WAN)
Microwave and satellite transmission
Long-distance calls
International network
Transborder data flow
International laws
Fundamentals of Information Systems, Second Edition

18. Fundamentals of Information Systems, Second Edition
A Typical LAN
Fundamentals of Information Systems, Second Edition

19. Fundamentals of Information Systems, Second Edition
A Wide Area Network
Fundamentals of Information Systems, Second Edition

20. Connecting Computing Devices Using a Home Network
Fundamentals of Information Systems, Second Edition

21. Communications Software and Protocols
Communications software - provides a number of important functions in a network
Network operating system - controls the computer systems and devices on a network and allows them to communicate with each other
Network management software - a manager can monitor the use of individual computers and shared hardware
Communications protocol - rules and standards that make communications possible
Fundamentals of Information Systems, Second Edition

22. Common Communications Protocols
Description
Open Systems Interconnection (OSI)
Divides data communication into seven layers for maintenance
Transport control protocol/Internet Protocol (TCP/IP)
Primary communication protocol of the Internet
Ethernet
Used in LANs
Asynchronous transfer mode (ATM)
Organizes data into 53-byte cells for fast transmission
802.11a
Supports wireless ATM devices
Bluetooth
Wireless communication for cell phones, handheld computers
802.11b (Wi-fi)
Fundamentals of Information Systems, Second Edition

23. Use and Functioning of the Internet
Fundamentals of Information Systems, Second Edition

24. Routing Messages Over the Internet
Fundamentals of Information Systems, Second Edition

25. Fundamentals of Information Systems, Second Edition
How the Internet Works
Internet Protocol (IP): Set of rules to pass packets from one computer to another
Transport Control Protocol (TCP): Set of rules to establish and break connections
Internet Protocol Address: Unique address for each computer on the Internet
Static vs. dynamic
Fundamentals of Information Systems, Second Edition

26. U.S. Top-Level Domain Affiliations
Fundamentals of Information Systems, Second Edition

27. Three Ways to Access the Internet
Fundamentals of Information Systems, Second Edition

28. Internet Service Providers
Organizations that provide access to the Internet
Choose based on price, reliability, other features ( address)
Examples: Superonline, E-kolay
Fundamentals of Information Systems, Second Edition

29. Internet and Telecommunications Services
Fundamentals of Information Systems, Second Edition

30. Summary of Internet Services (1)
Instant messaging
Telnet/SSH
FTP
Chat rooms
Internet phone
Internet video conferencing
Fundamentals of Information Systems, Second Edition

31. Summary of Internet Services (2)
Shop on the Web:
Auctions:
Distance learning
Music, radio on the Internet
Fundamentals of Information Systems, Second Edition

32. Common Abbreviations Used in Personal E-Mail
Fundamentals of Information Systems, Second Edition

33. Two Approaches to Electronic Data Interchange
Fundamentals of Information Systems, Second Edition

34. Public Network and Specialized Services
Fundamentals of Information Systems, Second Edition

35. Fundamentals of Information Systems, Second Edition
The World Wide Web
Fundamentals of Information Systems, Second Edition

36. Fundamentals of Information Systems, Second Edition
The World Wide Web
An Internet service comprising tens of thousands of independently owned computers that work together as one.
Home page: Cover page with text and graphics
Hypertext markup language (HTML): Standard language to describe Web pages
Fundamentals of Information Systems, Second Edition

37. Several Interesting Web Sites
Fundamentals of Information Systems, Second Edition

38. Fundamentals of Information Systems, Second Edition
Sample HTML
Fundamentals of Information Systems, Second Edition

39. Fundamentals of Information Systems, Second Edition
Search Engine
Fundamentals of Information Systems, Second Edition

40. Intranets and Extranets
Fundamentals of Information Systems, Second Edition

41. Intranets and Extranets
Intranet – an internal corporate network built using Internet and WWW standards and products
Extranet - a network that links selected resources of the intranet of a company with its customers, suppliers, or other business partners
Virtual private network - a secure connection between two points across the Internet
Firewall - a device that sits between your internal network and the outside Internet
Fundamentals of Information Systems, Second Edition

42. Summary of Internet, Intranet, and Extranet Users
Fundamentals of Information Systems, Second Edition

43. Virtual Private Network
Fundamentals of Information Systems, Second Edition

44. Fundamentals of Information Systems, Second Edition
Net Issues
Fundamentals of Information Systems, Second Edition

45. Fundamentals of Information Systems, Second Edition
Privacy and Security
Cookie: Text that is put on user computer to track Web site usage
Cryptography: Converting a message into a secret code and then back into the message
Encryption
Digital Signature: Who sent the message, did the message change on the way?
Fundamentals of Information Systems, Second Edition

46. Fundamentals of Information Systems, Second Edition
Cryptography
Fundamentals of Information Systems, Second Edition

47. Fundamentals of Information Systems, Second Edition
Summary
Networks - used to share hardware, programs, and databases across the organization.
Internet - transmits data from one computer (called a host) to another.
The Web - a collection of tens of thousands of independently owned computers that work together as one in an Internet service.
Fundamentals of Information Systems, Second Edition