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Introduction to Information Systems
Session 8
Session 5
Session 6
Session 7
Session 8
Session 14
Session 15

 

Objective:

  1. Real World Case Study - Loudcloud, Inc.:Creating an outsourced, managed, intelligent web network.
  2. Define the term telecommunications and describe the components of a telecommunications system.
  3. Describe how the Internet works
  4. Describe the services associated with the Internet, including the WWW.
  5. Define the terms intranet and extranet and discuss how organizations are using them
  6. Identify several issues associated with the use of networks.

A Telecommunication:

1. Telecommunications has the potential to create profound changes in business because it lessens the barriers of time and distance.

2. The elements of a telecommunications system start with a sending unit that originates the message. The sending unit transmits a signal to a telecommunications device. The telecommunications device performs a number of functions, which can include converting the signal into a different form or from one type to another. The telecommunications device then sends the signal through a medium, which carries the electronic signal and interfaces between a sending device and a receiving device. The signal is received by another telecommunications device that is connected to the receiving computer. (See Figure 1.1 below)

< figure 1.1>

3. A Network is two or more computers connected together by some means.
Common Network Cables :

-Twisted Pair or RJ45 (looks like a fat telephone cable, most common of all cables)
- Coaxial (same as your TV cable)
- Fiber Optic (used in large installation using light to carry the signal)

4. Components that are used to help connect computers together are called Devices.
Common Network Devices are:

- HUB - Cheap, Easy to Install, Reliable, simply connect machines together, broadcasts
- SWITCH - Smarter than a hub in that it learns where devices are (little or no broadcasting), however, it is not programmable.
- ROUTER - smart, learns where things are on a network and remembers how to get to them. You can program Routers to route information in a particular way.

HUB

SWITCH

ROUTER

An example of using hub, switch, and router to set up a network: (See figure 1.2)

<figure 1.2>

5.The letter "A" is an example of the size of a Byte.

- It takes 8 bits (0's and 1's) to make up a Byte
- File size is always measured in Bytes
- Speed is always measured in bits per sec (bps)
- A 1.5 MB File would take 8 seconds to transfer over a 1.5 Mbps Network connection

<figure 1.3>

6. The spectrum of telecommunications-based services available today:

Entertainment

 

 

 

Information Transaction

 

 

 

Communications

  • Broadcast TV
  • High-definition TV
  • Enhanced pay-per-view
  • Video-on-demand
  • Interactive TV
  • Interactive video games
  • Video catalog shopping
  • Distance learning
  • Desktop multimedia
  • Image networking
  • Transaction services
  • Internet access
  • Telecommuting
  • Videoconferencing
  • Video telephone
  • Mobile radio
  • Cellular/PCS systems
  • POTS-Plain old telephone service

Shaw Entertainment Bundles

Telus services

7.Major trends in business telecommunications.

8. Network Topologies:

- A star network ties end user computers to a central computer. It is considered less reliable than a ring network, since the other computers in the star are heavily depend on the central host computer. If it fails, there is no backup processing and communications capability, and the local computers are cut off from each other. Therefore, it's essential that the host computer be highly reliable.

-A ring network ties local computer processors together in a ring on a more equal basis. Ring and bus networks are most common in local area networks. Ring networks are considered more reliable and less costly for the type of communications in such networks. If one computer in the ring goes down, the other computer can continue to process their own work as well as to communicate with each other.

- A bus network is a network in which local processor share the same bus, or communications channel.

Client/server networks may use a combination of star, ring,and bus approaches. Obviously, the star network is more centralized, while ring and bus networks have a more decentralize approach.

Star Network

Ring Network

Bus Network

B. How Internet Works?

  1. The Internet is the world's largest computer network - actually a collection of interconnected networks, all freely exchanging information. The Internet transmits data form one computer (called a host) to another. The set of conventions used to pass packets from one host to another is know as the Internet protocol (IP). Transport control protocol (TCP) includes rules for computers to establish and break connections. Each computer on the Internet has an assigned address to identify it form other hosts.
  2. An Internet service provider (ISP) is any company that provides individuals or organizations with access to the Internet. To use this type of connection, you must have an account with the service provider and software that allows a direct link via the TCP/IP protocols.
  3. Internet services include voice mail, e-mail, and instant messaging; telecommuting, video conferencing, and Internet phone service; electronic data interchange (EDI) ; public network and specialized services; distance leaning; on-line music, radio, and video; telnet, FTP, and content streaming; and chat room.
  4. The Web is a collection of tens of thousands of independency owned computers that work together as one in an Internet service. High-speed Internet circuits connect these computers, and cross-indexing software is employed to enable users to jump from one Web computer to another effortlessly. Because of its ability to handle multimedia objects and hypertext links between distributed objects, the Web is emerging as the most popular means of information access on the Internet today.
  5. A Web site is like a magazines, with a cover page called a home page that has graphics, titles, and text. Hypertext links are maintained using URL's (uniform resource locators), a standard way of coding the locations of the HTML (hypertext markup language ) documents.
  6. The client communicates with the server according to a set of rules call HTTP(Hypertext Transfer Protocol), which retrieves the document and presents it to the users. HTML is the standard page description language for WEB pages. A Web browser reads HTML and creates a unique, hypermedia-based menu on the user's computer screen that provides a graphical interface to the Web.
  7. A rapidly growing number of companies are doing business on the Web, enabling shoppers to search for and buy products on-line. The travel, entertainment, gift, greetings, book and music business are experiencing the fastest growth on the Web.
  8. An Intranet is an internal corporate network built using Internet and World Wide Web standards and products. It is used by the employees of the organization to gain access to corporate information.
  9. An Extranet is a network that links selected resources of the intranet of a company with its customers, suppliers, or other business partners. It is built based on Web technologies. Authentication, privacy, and performance are critical on an extranet.
  10. Management issues, service bottlenecks, privacy and security, and firewalls are issues that affect all networks.
  11. Exercise: Find out the meanings of the following terms. TCP/IP, ISP(Internet Service Provider), Web Hosting Company, IP Address, Name Address, Domain Name Address, Intranet, Extranet, EDI (Electronic Data Interchange),Downsizing, Legacy Systems, Open Systems, Firewalls.

C. In the Lab

1.Find out your computer IP address.

2. How to Register a Domain Name?

3.Who owns your domain name? Whois Domain Name Search

4.Who is Verisign? How do I know I'm at a secure zone? Use RBC as an example.

5. Sign up for a free hosting company.