1. Working Outside the Box

2. Basic Concepts Telecommunications Basics 
The Internet, a network of networks 
The World-wide-web, an Internet implementation 
Serious Issues  
MIS 300, Chapter 4

3. Principles and Learning Objectives -1
Effective communications are essential to organizational success. 
Define the term telecommunications and describe the function of the components of a telecommunications system.
Identify the three types of telecommunications carriers and discuss the services they provide.
Name three distributed processing alternatives and outline their basic features.
MIS 300, Chapter 4

4. Principles and Learning Objectives -2
The Internet is like many other technologies—it provides a wide range of services, some of which are effective and practical for use today, others are still evolving, and still others will fade away from lack of use. 
Briefly describe how the Internet works, including alternatives for connecting to it and the role of Internet service providers.
MIS 300, Chapter 4

5. Principles and Learning Objectives -3
Originally developed as a document-management system, the World Wide Web is a menu-based system that is easy to use for personal and business applications. 
Describe the World Wide Web and the way it works, including the use of Web browsers, search engines, and other Web tools.
MIS 300, Chapter 4

6. Principles and Learning Objectives -4
Because the Internet and the World Wide Web are becoming more universally used and accepted for business, management, service, and speed, privacy and security issues must continually be addressed and resolved. 
Identify and briefly describe the applications associated with the Internet and the Web.
Define the terms intranet and extranet and discuss how organizations are using them.
Identify several issues associated with the use of networks.
MIS 300, Chapter 4

7. An Overview of Telecommunications and Networks
Telecommunications: the electronic transmission of signals for communications
Telecommunications medium: anything that carries an electronic signal and interfaces between a sending device and a receiving device
Telecommunications carrier: any business that provides (leases, services) telecommunications media.
Telecommunications service: any service to customers at least partially facilitated by telecommunications
MIS 300, Chapter 4

8. Communication Model Meaning-2 Meaning-1 Expression Interpretation
Sender
Channel
Receiver
Encoding
Decoding
M e s s a g e
Challenges:
1. Various processes 2. Will meanings match? 3. Why encode? 4. Purpose? Intention?
MIS 300, Chapter 4

9. Characteristics of Communication
Encoding/decoding scheme
Speed of transmission (baud)
Directionality (one-way, bidirectional, switchable)
Noise
Equivocation (loss of signal)
Ambiguity (loss of meaning)
Turntaking (protocol)
MIS 300, Chapter 4

10. The Telecommunications Problem
Sender
Channel
Receiver
Encoding
Decoding
Distance: Sender and Receiver are not in direct contact Equivocation: Message loses power over distance Noise: Channel introduces unwanted message Coordination: It’s not clear what a message event is
MIS 300, Chapter 4

11. Solutions to the problems
Sender
Channel
Receiver
Encoding
Decoding
Distance: Long “wires” of various types Equivocation: Boosting of power (introduces noise) Noise: Special encoding schemes Coordination: Coordination messages (protocols)
Notice: Nothing about meaning, intention
MIS 300, Chapter 4

12. Basic Economics Sources aren’t “on” all the time
Sources make mistakes; repetition is dangerous and costly
Channels are usually relatively expensive
Sharing channels is a good use of an expensive resource; sharing is costly
All channels are error-prone; the way to compensate is redundancy
The more complex the scheme, the higher the cost and the more likely is failure or error.
MIS 300, Chapter 4

13. What Is a Signal? A communication event Has a definite start and stop
ANALOG signal: strength is proportional to “content”
A communication event
Has a definite start and stop
Carries information (which is NOT the signal)
DIGITAL signal: strength is fixed at either 0 or a constant 1 1 1 1 1
MIS 300, Chapter 4

14. Inside a Digital Signal
The bits that form part of the byte may be ones (at or above a certain level) or zero (below this level). This byte is (1’s in color)
Beginning of byte has special “bit” called a start bit
Ending of byte has special “bit” called a stop bit
MIS 300, Chapter 4

15. What Is the Advantage of Digital Signalling?
First, simplicity, only two signal levels
Second, resistance to noise
Third, amplification can work without amplifying noise
Fourth, potential to add check bits to reconstruct byte in the event of errors (for example, parity checking).
MIS 300, Chapter 4

16. Amplification Noise intrudes Over distance, signal weakens
“On” threashold
Noise intrudes
Over distance, signal weakens
Original 0-1
…and then amplified
Signal is “clipped” at threashold level
…and sent on its way again
MIS 300, Chapter 4

17. The Equipment is Connected
This is only what you see!
Figure 4.1: Elements of a (Physical) Telecommunications System
MIS 300, Chapter 4

18. Transmission Media -1
Table 4.1: Telecommunications Transmission Media Types
MIS 300, Chapter 4

19. Transmission Media - 2
Table 4.1: Telecommunications Transmission Media Types
MIS 300, Chapter 4

20. Telecommunications Devices
Table 4.2: Common Telecommunications Devices
MIS 300, Chapter 4

21. Carriers and Services
Local exchange carrier (LEC): a public telephone company in the United States that provides service to homes and businesses within its defined geographical area
Competitive local exchange carrier (CLEC): a company that is allowed to compete with the LECs, such as a wireless, satellite, or cable service provider
Long-distance carrier: a traditional long-distance phone provider, such as AT&T, Sprint, or MCI
MIS 300, Chapter 4

22. Carriers and Services (continued)
Figure 4.3: Local Exchange Carriers
MIS 300, Chapter 4

23. Networks
Computer network: the communications media, devices, and software needed to connect two or more computer systems or devices
Network nodes: the computers and devices on the networks
Node
MIS 300, Chapter 4

24. What Are Networks For?
At an electrical level, networks move electrons along paths between nodes
At a signal level, networks move coded characters along links connecting nodes
At a transportation level, networks move packages or packets of characters between source and destination along paths within the network
At a session level, networks move messages from sender to receiver.
At the application level, networks move information from a server to a client.
Businesses can select various ways for this to happen.
MIS 300, Chapter 4

25. Basic Processing Strategies
Centralized processing: all processing occurs in a single location or facility
Decentralized processing: processing devices are placed at various remote locations
Distributed processing: computers are placed at remote locations but connected to each other via a network
MIS 300, Chapter 4

26. Terminal-to-Host, File Server, and Client/Server Systems
Connecting computers in distributed information processing:
Terminal-to-host: the application and database reside on one host computer, and the user interacts with the application and data using a “dumb” terminal
File server: the application and database reside on the one host computer, called the file server
Client/server: multiple computer platforms are dedicated to special functions, such as database management, printing, communications, and program execution
MIS 300, Chapter 4

27. Terminal-to-Host, File Server, and Client/Server Systems -2
Figure 4.6: Client/Server Connection
MIS 300, Chapter 4

28. Network Types Personal area network (PAN) Local area network (LAN)
Metropolitan area network (MAN)
Wide area network (WAN)
International network
Corrupt local area network (CLAN) 
MIS 300, Chapter 4

29. Network Types -2
Figure 4.7: A Typical LAN
MIS 300, Chapter 4

30. Network Types - 3
Figure 4.8: A Wide Area Network
MIS 300, Chapter 4

31. Communications Software and Protocols
Communications software: software that provides a number of important functions in a network, such as error checking and data security
Network operating system (NOS)
Network management software
Communications protocol: a standard set of rules that controls a telecommunications connection
MIS 300, Chapter 4

32. Packet Switching
Sender’s message is broken into (generally short, fixed-length) packets
Each packet is numbered and sent “into” the network
The network transmits the packets
The node assembles the packets in order (not an easy task)
The receiver gets the message from the node.
MIS 300, Chapter 4

33. Example of Packet Switching
456
Message
FROM: Node 223
TO: Node 456
Count: 4
This is packet 1
This is packet 2
This is packet 3
This is packet 4 P3 P2
223 P4 P4 P1 P3 P2
Packet reassembly
Transmission: each packet has its own path through the network P1
Costs Benefits
Packet creation Better use of network Packet handling Smaller units Chance of error More even use of n/w Retransmissions Higher traffic
Packet creation
MIS 300, Chapter 4

34. Use and Functioning of the Internet
Internet: a collection of interconnected networks, all freely exchanging information
ARPANET
The ancestor of the Internet
A project started by the U.S. Department of Defense (DoD) in 1969
Internet Protocol (IP): communication standard that enables traffic to be routed from one network to another as needed
MIS 300, Chapter 4

35. How the Internet Works
The Internet transmits data from one computer (called a host) to another
If the receiving computer is on a network to which the first computer is directly connected, it can send the message directly
If the receiving computer is not on a network to which the sending computer is connected, the sending computer relays the message to another computer that can forward it
MIS 300, Chapter 4

36. How the Internet Works (continued)
Figure 4.9: Routing Messages over the Internet
MIS 300, Chapter 4

37. How the Internet Works (continued)
Data is passed in chunks called packets
Internet Protocol (IP): communications standard that enables traffic to be routed from one network to another as needed
Transmission Control Protocol (TCP): widely used transport-layer protocol that is used in combination with IP by most Internet applications
Uniform Resource Locator (URL): an assigned address on the Internet for each computer
MIS 300, Chapter 4

38. Accessing the Internet
Connect via a LAN server
Connect via Serial Line Internet Protocol (SLIP)/Point-to-Point Protocol (PPP)
Connect via an online service
Other ways to connect
MIS 300, Chapter 4

39. Accessing the Internet (continued)
Figure 4.10: Several Ways to Access the Internet
MIS 300, Chapter 4

40. Internet Service Providers
Internet service provider (ISP): any company that provides individuals or organizations with access to the Internet
Most charge a monthly fee
Many ISPs and online services offer broadband Internet access through digital subscriber lines (DSLs), cable, or satellite transmission 
MIS 300, Chapter 4

41. The World Wide Web The Web, WWW or W3
A menu-based system that uses the client/server model
Organizes Internet resources throughout the world into a series of menu pages, or screens, that appear on your computer
Hypermedia: tools that connect the data on Web pages, allowing users to access topics in whatever order they want
MIS 300, Chapter 4

42. The World Wide Web (continued)
Hypertext Markup Language (HTML): the standard page description language for Web pages
HTML tags: codes that let the browser know how to format the text on a Web page and whether images, sound, and other elements should be inserted
MIS 300, Chapter 4

43. The World Wide Web (continued)
Figure 4.11: Sample Hypertext Markup Language
MIS 300, Chapter 4

44. Web Browsers
Web browser: software that creates a unique, hypermedia-based menu on a computer screen, providing a graphical interface to the Web
The menu consists of graphics, titles, and text with hypertext links
Ubiquitous and non-proprietary web browsers make it possible for the Internet to be a business platform.
MIS 300, Chapter 4

45. Search Engines Search engine: a Web search tool
Examples: Yahoo.com, Google.com
Most search engines are free
Searches can use words, such as AND and OR, to refine the search
MIS 300, Chapter 4

46. Web Programming Languages
Java
An object-oriented programming language from Sun Microsystems based on C++
Allows small programs (applets) to be embedded within an HTML document
MIS 300, Chapter 4

47. Web Services
Standards and tools that streamline and simplify communication among Web sites for business and personal purposes
Can also be used to develop new systems to send and receive secure messages between healthcare facilities, doctors, and patients, while maintaining patient privacy
MIS 300, Chapter 4

48. Internet and Telecommunications Services
and instant messaging
Instant messaging: a method that allows two or more individuals to communicate online, using the Internet
Internet cell phones and handheld computers
Career information and job searching
Web log (blog): a Web site that people can create and use to write about their observations, experiences, and feelings on a wide range of topics
MIS 300, Chapter 4

49. Internet and Telecommunications Services (continued)
Chat rooms: enable two or more people to engage in interactive “conversations” over the Internet
Internet phone and videoconferencing services
Content streaming: a method for transferring multimedia files over the Internet so that the data stream of voice and pictures plays more or less continuously without a break, or very few of them
Shopping on the Web
MIS 300, Chapter 4

50. Internet and Telecommunications Services (continued)
Web auctions
Music, radio, and video on the Internet
Other Internet services and applications
MIS 300, Chapter 4

51. Intranets and Extranets
Internal corporate network built using Internet and World Wide Web standards and products
Used by employees to gain access to corporate information
Slashes the need for paper
MIS 300, Chapter 4

52. Intranets and Extranets (continued)
A network based on Web technologies that links selected resources of a company’s intranet with its customers, suppliers, or other business partners
Virtual private network (VPN): a secure connection between two points across the Internet
Tunneling: the process by which VPNs transfer information by encapsulating traffic in IP packets over the Internet
MIS 300, Chapter 4

53. Intranets and Extranets (continued)
Figure 4.12: Virtual Private Network 
MIS 300, Chapter 4

54. Net Issues Management issues Service and speed issues
No centralized governing body controls the Internet
Service and speed issues
Web server computers can be overwhelmed by the amount of “hits” (requests for pages)
More and more Web sites have video, audio clips, or other features that require faster Internet speeds
MIS 300, Chapter 4

55. Net Issues (continued)
Privacy
Spyware: hidden files and information trackers that install themselves secretly when you visit some Internet sites
Cookie: a text file that an Internet company can place on the hard disk of a computer system
Fraud
Phishing
MIS 300, Chapter 4

56. Net Issues (continued)
Security with encryption and firewalls
Cryptography: converting a message into a secret code and changing the encoded message back to regular text
Digital signature: encryption technique used to verify the identity of a message sender for processing online financial transactions
Firewall: a device that sits between an internal network and the Internet, limiting access into and out of a network based on access policies
MIS 300, Chapter 4

57. Net Issues (continued)
Figure 4.13: Cryptography is the process of converting a message into a secret code and changing the encoded message back into regular text. 
MIS 300, Chapter 4

58. Summary
Telecommunications is the electronic transmission of signals for communications
A computer network consists of the communications media, devices, and software needed to connect two or more computer systems or devices
Ways of connecting computers in distributed information processing: terminal-to-host, file server, and client/server
MIS 300, Chapter 4

59. Summary (continued)
Network types: personal area network (PAN), local area network (LAN), metropolitan area network (MAN), wide area network (WAN), and international network
The Internet is a collection of interconnected networks, all freely exchanging information
Internet Protocol (IP) is a communication standard that enables traffic to be routed from one network to another as needed
MIS 300, Chapter 4

60. Summary (continued)
Uniform Resource Locator (URL) is an assigned address on the Internet for each computer
An intranet is an internal corporate network built using Internet and World Wide Web standards and protocols
An extranet is a network based on Web technologies that links selected resources of a company’s intranet with its customers, suppliers, or other business partners
MIS 300, Chapter 4