1. Internet…issues Managing the Internet
Interaction between Internet components
Data transmission and protocols
IP addresses and domain names
FTP and Telnet
HTML and XLM
and instant messaging
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2. Management of the Internet
Who owns the Internet?
Individuals
Universities
Government agencies
Private companies
Who manages the Internet?
Nonprofit organizations
User groups
Who pays for the Internet?
US taxpayers
Businesses
Universities
Other countries
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3. Internet Networking A network of networks: Network hierarchy T lines
Worldwide network of computer systems
Communications protocols
Network hierarchy
T lines
Network access points
Points of Presence
The network model
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4. Network Hierarchy Tier 1: Tier 2: Tier 3: The Internet backbone
Moves large amounts of data
Provide access to Regional ISPs
Tier 2:
Regional ISPs
Provide access to local ISPs
Tier 3:
Local ISPs
Provide Internet access to homes and businesses
Tier 3 ISP
Tier 2 ISP

5. T Lines High speed fiber-optic lines T-1 line: T-2 lines: T-3 lines:
24 simultaneous voice or data channels
1.544 Mbps throughput
T-2 lines:
4 T-1 lines
6.3 Mbps throughput
T-3 lines:
28 T-1 lines
44.76Mbps throughput
T-4 lines:
168 T-1 lines
Mbps throughput

6. Network Access Points (NAPs)
Points of connection between ISPs
Routers move data between networks
Tier 1 ISP
Routers
Routers
Tier 2 ISPs
Tier 2 ISPs
Routers

7. Points of Presence (POP)
Bank of modems where individual users connect to an ISP
Other computers
Your ISP
Point of Presence
Your computer

8. Network Model
Internet communications follows the client/server network model
Clients request services
Servers respond to requests
Types of servers include:
Web servers:
Host Web pages
Commerce servers:
Enables the purchase of goods and services over the Internet
File servers:
Provide remote storage space for files that users can download

9. Animation: Network Model
4. Your request goes to the National Backbone Network
Click to view animation. Click once only.
Network Access Point (NAP)
2. Your request goes to your ISP’s point of presence (POP).
1. You request a Web page.
National Backbone Network
5. Your request goes to the Web site’s server
3. Your request goes to a Network Access Point
The Web page is sent back to you in packets.
YOU ARE HERE
ISP’s Point of Presence (POP).
Web site’s server

10. Data Transmission and Protocols
Computer protocols are rules for electronic information exchange
Open system protocols:
Any computer can communicate with other computers using the same protocols
Circuit switching
Packet switching
TCP/IP
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11. Circuit Switching Dedicated connection between two points
Remains active until the transmission is terminated
Telephone communications

12. Packet Switching Data is broken into small units called packets
Packets are sent over various routes to their destination
Packets are reassembled by the receiving computer
Packets contain:
Destination/source addresses
Reassembling instructions
Data

13. Animation: Packet Switching
ISP New York
Web Page
Data Packets 01 02 03 04 05 06 07 08 09 10 11 12
Your ISP 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Click to view animation 25 26 27 28 29 30
ISP Virginia
ISP Florida
Your Computer

14. TCP/IP Transmission Control Protocol (TCP): Internet Protocol (IP):
Prepares data for transmission
Provides error checking
Enables resending lost data
Internet Protocol (IP):
Responsible for sending data from one computer to another

15. IP Addresses
Unique number that identifies devices connected to the Internet
Typical IP address:
Static address:
Address never changes
Dynamic address:
Temporary address
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16. Domain Names Name that takes the place of an IP address
Sample domain name:
Top level domains (TLD):
Portion of the domain name that follows the period (dot)
Sample top level domain names:
.com; .org; .edu; and .net
Second-level domains:
Unique name within a top level domain
Sample second-level domain names:
Yahoo.com; Google.com; and Unesco.org
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17. Other Protocols File Transfer Protocol (FTP): Telnet:
File sharing protocol
Files are downloaded and uploaded using the Internet
Telnet:
Protocol for connecting to a remote computer and a TCP/IP service
Enables a client computer to control a server computer
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18. HTTP and SSL Hypertext Transfer Protocol: Secure Socket Layer:
Protocol for transferring hypertext documents
Hypertext documents are linked to other documents
Hyperlink
Secure Socket Layer:
Security protocols that protect sensitive information
Encrypts data
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19. HTML Hypertext Markup Language: Format for creating Web pages
Not a programming language but a set of rules for marking up text
HTML
Web Page
<h1>This is the Heading</h1>
<p><font face="Arial">This is text using Arial font.</font></p>
<p><font face="Arial"><i>This text is italicized</i>.</font></p>
<p><font face="Arial"><b>This text is bold</b>.</font></p>
<p><font face="Arial"><font color="#FF0000">This text color is red</font>.</font></p>
<p><font face="Arial">This is a hyperlink <a href="
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20. Common Gateway Interface (CGI)
Browsers request that a program file executes (runs)
Adds Web page interaction:
Adding names to guest books/mailing lists
Completing forms
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21. Client-Side Application
A program that runs on a client computer with no interaction with the server
Types of client-side applications include:
HTML document embedded with JavaScript code
Applet:
Small program that resides on the server
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22. Extensible Markup Language (XML)
Designed for information exchange
Tools used to create your own markup language
Used in e-commerce transactions
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23. Communications Over the Internet
Created in 1971 by Ray Tomlinson
Simple Mail Transfer Protocol (SMTP)
Multipurpose Internet Mail Extensions (MIME)
Protocol for attaching files to
security:
Encryption:
Private-key encryption
Public-key encryption
Secure data transmission software
SafeMessage
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24. Instant Messaging (IM)
Client/server application program for real-time, text based conversations
Popular instant messaging programs:
AOL Instant Messenger
ICQ
Yahoo! Messenger
Windows Messenger
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