Business Data Communications,
Fourth Edition
Chapter 12: The Internet
Learning Objectives
• Explain the history of the Internet
• Describe early commands used on the
Internet
• List and describe the advisory
organizations concerned with the Internet
• Explain Internet addressing schemes
Chapter 12: The Internet
2
Learning Objectives
• Describe how the Internet works
• Discuss the languages used to create
Web pages
• Describe Internet services such as search
programs, newsgroups, and mailing lists
Chapter 12: The Internet
3
Introduction to Chapter
• The Internet is widely used by researchers and
consumers
• “Internet” is a named network, “internet” is the
interconnection of networks
• The Internet is one of the oldest WANs
• The Internet connects homes, schools,
businesses worldwide
• The history and foundation are important
aspects to understanding the makeup of the
Internet
Chapter 12: The Internet
4
Chapter 12: The Internet
5
History of the Internet
• Advanced Research Projects Agency (ARPA)
wanted to link remote research sites
• Created ARPANET in 1969
• Originally had 4 nodes, used Network Control
Protocol (NCP)
• Converted to Transmission Control
Protocol/Internet Protocol (TCP/IP) in 1983 to
allows different OS to communicate
• Computer Science Network (CSNet) – Provided
connections between universities and industry
Chapter 12: The Internet
6
History of the Internet
• Because It’s Time Network (BITNET) –
connected university networks
• National Science Foundation Network (NSFnet)
–
–
–
–
Funded in 1987
Used to connect supercomputers
Backbone network
Regional networks took over in 1995
• Commercial Internet eXchange (CIX) – allowed
Internet access for commercial users
• Internet service providers (ISP) – provide access
to the Internet for commercial and private users
Chapter 12: The Internet
7
Chapter 12: The Internet
8
History of the Internet
• Internet2 (I2)
– High-speed network designed to replace the Internet
– Useful for hospitals, research, financial institutions
– Universities and other research institutions working
on it
– Abilene is the backbone network for I2
• Next Generation Internet (NGI)
– Funded by the US Department of Energy
– Closely tied to the development of Internet2
Chapter 12: The Internet
9
Early Internet Commands
• Telnet
– Used to access a remote computer
– telnet computer-name
– User ID and password required
– Can perform any command usually permitted
on that computer
– Anonymous Telnet
• No ID and password required
Chapter 12: The Internet
10
Chapter 12: The Internet
11
Early Internet Commands
• File Transfer Protocol (ftp)
– Used to transfer a file to a client computer
– FTP Client is the program used
• Examples: WS_FTP, CuteFTP
– ftp host-computer-name
– List of command-line commands used
– Anonymous FTP
• No ID and password required
• Usually need to give your e-mail address
Chapter 12: The Internet
12
Chapter 12: The Internet
13
Chapter 12: The Internet
14
Early Internet Commands
• Gopher
– Program that provides a menu for services on
an Internet site
– Widely used prior to WWW
– Gopher server and clients
– Can access Gopher sites using a browser
Chapter 12: The Internet
15
Early Internet Commands
• Archie
–Searches indexes of files on public
information servers
–System of databases
• Veronica
–Searches Gopher menus for topics
–More sophisticated than Archie
–Shows the actual Gopher menu, not just
returning the location as is done with Archie
Chapter 12: The Internet
16
Internet Addressing
• IP Addresses
– Unique address on the Internet
– Also known as a “dotted-quad”
• 140.222.32.3
– Internet Information Center (InterNIC)
registers the addresses
– Classes
•
•
•
•
•
Class A – Networks with more than 65,536 nodes
Class B – Networks with 256 to 65,536 nodes
Class C – Networks with fewer than 256 nodes
Class D – Broadcast messages
Class E – Experimental use
Chapter 12: The Internet
17
Chapter 12: The Internet
18
Internet Addressing
• IP Addresses
– Classless Internet Domain Routing (CIDR)
• Used to extend the number of IP addresses
• 186.100.0.0/20 – This one IP address can now cover
4096 additional addresses
Chapter 12: The Internet
19
Internet Addessing
• Domain Name System (DNS)
– Database of Internet names and
addresses
– Domain names – microsoft.com
– Companies buy the names from the
InterNIC and then sell them to others
– Domain – group of computers with a
common set of rules and procedures
• Top level domain – .com
Chapter 12: The Internet
20
Chapter 12: The Internet
21
Internet Addressing
• Domain Name System (DNS)
– Internet Ad Hoc Committee (IAHC) has added
new top level names
• Subdomains
– Businesscenter.ibm.com
– Nxt2.cso.uiuc.edu
– Domain Name Server – translates name to
the IP address
Chapter 12: The Internet
22
Chapter 12: The Internet
23
Chapter 12: The Internet
24
Internet Addressing
• Electronic Mail Addresses
– Individual address + domain name address
– Mail server
– Software is required
Chapter 12: The Internet
25
How the Internet Works
• Connections to the Internet
– ISP connection using a modem
– DSL (7Mpbs upload, 640 Kbps download)
– Network interface card (NIC) – used when
connecting through a corporate or university
network
– WebTV
– Cable Modems – 500 Kbps to 30 Mbps
depending on the number of people logged in
simultaneously
Chapter 12: The Internet
26
Chapter 12: The Internet
27
How the Internet Works
• Internet Backbones
– Network Service Providers (NSPs)
• Operate and maintain backbone networks
• Run local and national networks
• ISPs connect to the NSPs for their Internet
connections
– Network Access Point (NAP)
• Interconnection point for NSP backbone networks
– Regional Exchange Points
– Metropolitan Area Exchanges (MAEs)
• Interconnection point for NSP backbone networks
Chapter 12: The Internet
28
Chapter 12: The Internet
29
How the Internet Works
• Routers
– Provide Internet traffic control
– Identify where packets should be sent
• Servers
– Computers connected directly to the Internet
– Dedicated to serving data on the Internet
• Protocols
– TCP/IP used so many different types of
computers can communicate
– IPv6 will allow more addresses (128-bit
addresses)
Chapter 12: The Internet
30
Chapter 12: The Internet
31
How the Internet Works
• Protocols
– Internet Application Protocols
• Hypertext Transfer Protocol (HTTP)
• Network News Transfer Protocol (NNTP)
• Simple Mail Transfer Protocol (SMTP)
– Internet Engineering Task Force (IETF)
• Sets new protocols for the Internet
Chapter 12: The Internet
32
World Wide Web (WWW)
• Graphical user interface to the Internet
– Created by Tim Berners-Lee at CERN
– Geneva Switzerland, 1991
• Web pages
– Hyperlinks
– Web site
Chapter 12: The Internet
33
World Wide Web (WWW)
• Web Programming
– Hypertext Markup Language (HTML)
– Tags (markups) are special instructions
– Can now create them using MS Word and
other software packages
– Enhanced Hypertext Markup Language
(eHTML)
– Java – object-oriented programming language
– Virtual Reality Modeling Language (VRML)
• Duplicate real-life environments
Chapter 12: The Internet
34
World Wide Web (WWW)
• Web Browsers
– First browser was Mosaic
– Netscape Navigator and Communicator
– Microsoft Internet Explorer
– Plug-ins
• Extends a browser’s capability
– Home pages
– Uniform Resource Locator (URL)
Chapter 12: The Internet
35
World Wide Web (WWW)
• Browsers
– Hypertext transport protocol (HTTP)
– http://www.pnc.edu
– Streaming audio and video
– RealPlayer
– MP3 player
• The Future of the Web
– Internet telephony
– Faster access through ISDN, DSL, cable
modems
Chapter 12: The Internet
36
Chapter 12: The Internet
37
Chapter 12: The Internet
38
Other Internet Services
• Search Programs
– Search engine is a program to search the web
– Some are specialized, some are general
Chapter 12: The Internet
39
Chapter 12: The Internet
40
Other Internet Services
• Newsgroups and Mailing Lists
(LISTSERVs)
– Newsgroups
• Articles published by individuals on the Internet
• Provides a discussion group service
– Mailing Lists (LISTSERVs)
• Must subscribe and unsubscribe
• Messages are delivered to you that are sent by
other LISTSERV members
• Moderated versus unmoderated lists
• LISTSERV moderator
Chapter 12: The Internet
41
Summary
• Millions of users access
the Internet
• History of Internet
includes many other
networks
• Internet Information
Center controls Internet
addresses
• Electronic mail is widely
used on the Internet
Chapter 12: The Internet
• World Wide Web is
accessed using one of
many browsers
• Telnet, FTP, Gopher,
Archie and Veronica are
text-based programs for
accessing Internet
• Newsgroups and
LISTSERVs are available
for exchanging
information on the
Internet
42