The document provides an overview of basic internet concepts including modems, types of networks, transmission media, the internet, domains, web browsers, search engines, and virtual private networks. It describes how digital signals are converted to analog and vice versa to transmit data over phone lines and fiber optics. The summary also explains how Google indexes web pages and how virtual private networks create secure connections over the public internet.

1. Title:Basic lesson before starting
internet
By: Amritpal singh sandhu
Roll no: 115355
1

2. Main Points:
Modem
Types of Networks
Types of Transmission Media
The Internet
The Global Internet

3. Modem
Functions of the Modem
The digital signals can be sent to other computers over
analog cables such as telephone lines. Note that digital
signals are representations of the two binary digits, 0 and
1, and are represented as on and off electrical pulses.
Figure 7-5

4. Modem
• Signals: digital vs. analog
• A modem is a device that translates digital
signals from a computer into analog form so
that they can be transmitted over analog
telephone lines.
• The modem also translates analog signals back
into digital form for the receiving computer.

5. Types of Networks
• Types of networks
1. Local-area networks (LANs)
• Client/server or peer-to-peer
• Ethernet –
• dominant LAN standard at the physical
network level
• Specifying the physical medium to carry
signals between computers
• Data transfer rate: 10 Mbps
• New version: Fast Ethernet and Gigabit
Ethernet
• Topologies: star, bus, ring

6. Management Information Systems
Chapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
Network Topologies
Figure 7-6
The three basic network
topologies are the bus,
star, and ring.

7. Types of Networks
• In a star topology
all devices on the network connect to a single hub and all
network traffic flows through the hub
• In a bus topology
one station transmits signals, which travel in both directions
along a single transmission segment.
All of the signals are broadcast in both directions to the entire
network.
All machines on the network receive the same signals, and
software installed on the client’s enables each client to listen for
messages addressed specifically to it

8. Types of Networks
• A ring topology
connects network components in a closed loop.
Messages pass from computer to computer in only one
direction around the loop, and only one station at a time may
transmit.
The ring topology is primarily found in older LANs using
Token Ring networking software

9. Types of Networks
2. Campus-area networks (CANs)
3. Wide-area networks (WANs)
4. Metropolitan-area networks (MANs)

10. Types of Transmission Media
• Physical transmission media
• Twisted wire (modems)
• Coaxial cable
• Fiber optics and optical networks
Many of the telephone systems in buildings had twisted wires
installed for analog communication, but they can be used for
digital communication as well. Also, today,
telecommunications companies are starting to bring fiber
optic cable into the home for high-speed Internet access.

11. Types of Transmission Media
• Wireless transmission media and devices
• Microwave
• Satellites
• Cellular telephones
• Transmission speed
• Hertz
• Bandwidth

12. Management Information Systems
Chapter 7 Telecommunications, the Internet, and Wireless Technology
Communications Networks
BP Amoco’s Satellite Transmission System
Figure 7-7
Communication satellites help BP Amoco transfer seismic data between
oil exploration ships and research centers in the United States.

13. The Internet
• What is the Internet?
• Connecting to the Internet
• Internet service providers (ISPs)
• Services
• DSL, cable, satellite, T lines (T1, T3)
• T lines are leased, dedicated lines suitable for businesses or
government agencies requiring high-speed guaranteed
service levels.

14. The Internet
• Internet addressing and architecture
• IP addresses (Define?)
• The domain name system
• Hierarchical structure
• Top-level domains

15. The Internet
The Domain Name System
Figure 7-8
The Domain Name System is a
hierarchical system with a root
domain, top-level domains,
second-level domains, and host
computers at the third level.

16. The Internet
• The Future Internet
• The IP addresses currently in use, such as
208.55.112.34 are part of a specification called
IP v 5. However, given the growth rate of the
Internet, there aren’t enough IP addresses in this
scheme to last beyond 2013. IP v 6 is a revised
addressing convention that will provide over a
quadrillion addresses
• IPv6
• Internet2, NGI

17. The Internet
• Internet services
• E-mail
• Chatting and instant messaging
• Newsgroups
• File Transfer Protocol (FTP)
• World Wide Web
• Voice over IP (VoIP)
• Unified communications: When firms are able to
merge disparate communications modes into a single
universally accessible service
• Virtual private networks (VPNs): is a secure,
encrypted, private network that has been configured
within a public network to take advantage of the
economies of scale and management facilities of large

18. The Internet
Client/Server Computing on the Internet
Figure 7-10
Client computers running Web
browser and other software can
access an array of services on servers
over the Internet. These services may
all run on a single server or on
multiple specialized servers.

19. The Internet
How Voice over IP Works
An VoIP phone call digitizes and breaks up a voice message into data packets that may travel along different routes before
being reassembled at the final destination. A processor nearest the call’s destination, called a gateway, arranges the packets
in the proper order and directs them to the telephone number of the receiver or the IP address of the receiving computer.
Figure 7-11

20. The Internet
• An VoIP phone call digitizes and breaks up a voice
message into data packets that may travel along
different routes before being reassembled at the final
destination.
• A processor nearest the call’s destination, called a
gateway, arranges the packets in the proper order and
directs them to the telephone number of the receiver
or the IP address of the receiving computer.
•Skype, acquired by eBay, offers free VoIP worldwide
using a peer-to-peer network.

21. The Internet
A Virtual Private Network Using the Internet
This VPN is a private network of computers linked using a secure “tunnel” connection over the Internet. It protects data transmitted
over the public Internet by encoding the data and “wrapping” them within the Internet Protocol (IP). By adding a wrapper around a
network message to hide its content, organizations can create a private connection that travels through the public Internet.
Figure 7-12

22. The Internet
• The World Wide Web
• HTML (Hypertext Markup Language):
• Formats documents for display on Web
• Hypertext Transfer Protocol (HTTP):
• Communications standard used for transferring
Web pages
• Uniform resource locators (URLs):
• Addresses of Web pages
• E.g.,
http://www.megacorp.com/content/features/082
602.html
• Web servers
• Software for locating and managing Web pages

23. The Global Internet
• Search engines
• Started in early 1990s as relatively simple software
programs using keyword indexes
• Google visited 50 billion web pages in 2007
• Today, major source of Internet advertising revenue via
search engine marketing, using complex algorithms
and page ranking techniques to locate results
• Sponsored links vs. organic search results

24. The Global Internet
• At the foundation of Google’s search engine are two concepts –
page ranking and the indexing of combinations of words
• How google works?
• The Google search engine is continuously crawling the
Web, indexing the content of each page, calculating its
popularity, and storing the pages so that it can respond
quickly to user requests to see a page. The entire process
takes about one-half second.
• Shopping bots
• Use intelligent agent software for searching Internet for
shopping information

25. The Global Internet
How Google Works
Figure 7-13
The Google search engine is
continuously crawling the
Web, indexing the content of
each page, calculating its
popularity, and storing the
pages so that it can respond
quickly to user requests to
see a page. The entire
process takes about one-half
second.

26. The Global Internet
Major Web Search Engines
This graphic ranks the major search engines according to popularity, or percentage of
total number of searches performed. Google is a clear favorite. Is this due to the
superiority of their search engine or does it involve other factors?