Transcript Internet
HIMA 4160
Fall 2009
The evolution of the Internet
Internet protocols
Different options for connecting to the
Internet
Common Internet applications
Censorship and privacy issues
The future of the Internet
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http://www.ted.com/talks/rives_controls_the
_internet.html
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The largest network of networks in the world.
Uses TCP/IP protocols and packet switching .
Runs on any communications substrate.
From Dr. Vinton Cerf,
Co-Creator of TCP/IP
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Internet: largest and most well-known computer
network, linking millions of computers all over the world
The Internet furnishes a standard way of sending messages and
information across virtually any type of computer platform and
transmission media
While Internet has become a household word only during the
past decade, it has actually operated in one form or another for
much longer than that
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1957 USSR launched sputnik. U.S. formed the APAR (Advanced Research
Projects Agency) in DoD.
1962: Paul Baran proposed the packet switching idea.
1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN
(Bolt, Beranek & Newman) to create ARPAnet
1970 - First five nodes:
UCLA, Stanford, UC Santa Barbara U of Utah, and BBN.
1972 – First email program was created by Ray Tomlinson
1974 - TCP specification by Vint Cerf
1981 – NSF created CSNET
1983 – Domain Name System (DNS) was created
1984 – On January 1, the Internet with its 1000 hosts converts en masse
to using TCP/IP for its messaging, NSFNet was created.
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1990 – DoD disbanded the APRANET and NSFNET
become the backbone. Tim Berners-Lee
implemented a hypertext system.
1992 – World Wide Web released by CERN.
1993 – First web browser Mosaic for X. Later
become Netscape.
1994 –Yahoo was established
1995 – NSFNet commercialized. Amazon was
launched
1998 – Google was launched.
2001 – “dot-com bubble” bursted.
2004 – the term web 2.0 was coined
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Users (people who use the Internet)
Internet service providers (ISPs) (provide
access to the Internet, typically for a fee)
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Internet content providers (provide Internet
content)
Application service providers (ASPs) (provide
access to Web-based software applications)
Infrastructure companies (own or operating the
physical structure of the Internet)
Hardware and software companies
The government and other organizations (Internet
Society, ICANN, W3C, etc.)
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Myth 1: The Internet is Free
Most people and businesses pay for Internet
access
Free services are often in exchange for
providing contact information or viewing
advertisements
Fee-based content is growing
Micropayments may be implemented in the
future for Web content
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Myth 2: Someone Controls the Internet
Governments can somewhat regulate Internet
use within its country but difficult to control it
well
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Myth 3: The Internet and World Wide Web
Are Identical
Internet = physical network
WWW = one resource (Web pages) available
via the Internet
Other resources are available via FTP, e-mail,
Telnet, etc.
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OSI model
Internet Protocols
Application
Presentation
DHCP, FTP , Http,
SMTP, Telnet, POP,
IMAP
MIME, SSL
Session
DNS
Transport
Network
TCP
IP
Data Link
Ethernet
Physical
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Ethernet
Protocols at the physical level
Used for LAN.
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IP
Internet Protocol
responsible for moving packet of data from node
to node
Forwards each packet based on a four byte
destination address (IP number). This is called
IPv4.
Guess what is IPv6?
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TCP
Transmission control protocol
Responsible for verifying the correct delivery of
data from computer to computer
Detect errors of lost data
Trigger retransmission until the data is correctly
and completely retrieved
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DNS
Domain Name System
Associate IP with domain names
Similar to phone book
Layers of networks
▪ Countries
▪ US
▪ mil, org, com, net, edu, gov
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MIME
Multipurpose Internet Mail Extension
Extend the format of email to support
▪ Content and attachment in non-text
SSL
Secure sockets layer
Cryptographic protocols that provide secure
communications on the Internet for such things as web
browsing, email and other data transfer.
Https = http + ssl.
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DHCP
Dynamic host configuration protocol
Used by computers on the network to obtain IP
address and other parameters from a CHCP
server.
FTP
File transfer protocol
Used to transfer data from one computer to
another over the internet.
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HTTP
Hypertext transfer protocol
Used to transfer or convey information on the Web.
Request/response protocol
Telnet
TELecommunication NETwork
Terminal emulation
Connect the pc to server
Command line based
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SMTP
Simple Mail Transfer Protocol
Used for email transmission across the internet.
POP
Post Office Protocol (POP)
Retrieve email from remote server using TCP/IP protocol.
IMAP
Internet Message Access Control
Allows a local client to access email on a remote server.
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In TCP/IP system, a port is a special number present
in the header of a data packet
Map data to particular process running on a
computer
FTP port 21
HTTP port 80
SMTP port 24
POP port 110
telnet port 23
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Getting set up to use the Internet typically
involves three decisions
Determining the type of device
Selecting the type of connection desired
Deciding on the Internet service provider t
Once these determinations have been made,
your computer can be set up to access the
Internet
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Possible devices include:
Desktop, notebook, or tablet PCs
Internet appliances
Mobile devices
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Need to be connected to the Internet to
access it
Connections can be:
Dial-up (PC has to dial via a phone line to
connect)
Direct (PC is continually connected to the
Internet)
Direct connections are typically broadband
Home broadband use is growing
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Dial-up connections
Conventional dial-up
▪ Slow, but cheap
▪ Ties up phone line
ISDN
▪ Faster, but pricey
▪ Doesn’t tie up phone line
▪ Used by businesses more than individuals
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Direct connections
T1 lines
▪ High-speed, usually used by schools and large
businesses
Cable
▪ Most widely used home broadband connection
DSL
▪ Broadband option for locations where it is available
(must be less than 3 miles from switching station)
Satellite
▪ Broadband option for rural areas
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Direct connections, cont’d
Fixed wireless
▪ Broadband option where available
Mobile wireless
▪ Access via mobile phone or device
▪ 3G is much faster than earlier types of
mobile wireless connections
Public hotspots
▪ Both free and fee-based are available
▪ Currently Wi-Fi so short range, but WiMAX
may soon be available
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http://www.free-hotspot.com/
http://www.speedtest.net/
http://network-tools.com/
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When selecting an ISP, consider
Services (e-mail limits and requirements, Web space,
etc.)
Speed (both upstream and downstream speeds,
consistency of service, etc.)
Support (free telephone support, response time,
etc.)
Cost (local access number for dial-up, hardware
costs, set-up fees, etc.)
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To set up your PC
Install necessary hardware
Install necessary software
Set up your telephone dialing software (for some
conventional dial-up connections only)
Select user name, access telephone number (for
dial-up connections), and a payment method
Change browser and e-mail settings as needed
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Search sites: Web sites that help you find Web
pages containing the information you are
seeking
Typically use a search engine in conjunction
with a database containing information about
Web pages to locate appropriate Web pages
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Types of online communications
Discussion groups (message boards, newsgroups, or
online forums)
Chat rooms: multiple users chat
Instant messaging (IM): exchange of real-time
messages
Videoconferencing (teleconferencing or Web
conferencing)
Voice over Internet Protocol (VoIP): Internet telephony
applications involve placing telephone-to-telephone calls
over the Internet—called VoIP
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Online shopping and investing
Be sure all e-commerce activities are performed
via a secure Web server
Online shopping
▪ Can purchase items via manufacturers, large
businesses, small businesses, etc/
▪ Usually paid via credit card, though other
options may be available
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Online shopping and investing, cont’d
Online auctions (eBay, etc.)
▪ Buy from individuals
▪ Seller pays auction fees
Online banking (transfer funds, check
balances, pay bills, etc.)
Online investing (buy and sell stocks, bonds,
and other securities
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Online entertainment
Online music (Internet radio stations, online music
stores, etc.)
Online TV (TV broadcast via the Internet)
Online videos (often found on news sites, popular TV
show sites, etc.)
Video-on-demand (VOD)
▪ Download movies and TV shows
▪ Often only viewable for a limited time
▪ Available for cell phones and mobile devices today
as well
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Online entertainment, cont’d
Video-on-demand (VOD)
▪ Download movies and TV shows
▪ Often only viewable for a limited time
▪ Available for cell phones and mobile devices today
as well
Online gaming (both individual and multiplayer
games played via the Internet)
E-books (purchased e-books and library e-books)
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Peer-to-peer file sharing: sharing
resources directly between users via the
Internet
Napster background and issues
Both legal and illegal peer-to-peer file sharing
exists today
With the availability of legal ways to obtain
digital content, some experts predict that,
eventually, legal alternatives will become the
norm for consumers
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Online news and research
News (online newspapers, magazines, news sites, etc.)
Product, corporate, and government information (lots
of information available online)
Reference sites (allow you to look up ZIP codes, phone
numbers, view maps, dictionary terms, etc.)
Portals: designed to be used as a browser’s home
page (Yahoo!, MSN, Bolt, etc.)
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Online education
Web-based training (WBT) and distance learning
▪ Advantages: Self-paced instruction, flexible
location, up-to-date material, immediate
feedback, and customized content
▪ Disadvantages: Technology requirements and
problems, anonymity, and lack of face-to-face
contact
Online testing (available for both objective and
performance-based exams)
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Online writing
Blogs (personal Web logs)
Wikis (editable collaborative Web page)
E-portfolios (personal online portfolio)
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Online broadcasting
Online radio
Podcasting (personal radio)
YouTube (personal video broadcasting)
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Match.com
MySpace
Facebook
Twitter
Monster.com
Linkedin.com
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Censorship
Free speech vs. offensive or indecent
materials
Internet
filtering:
using software
or browser
options to
block access
to particular
Web pages or
types of Web
pages
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Web as a platform
Harnessing collective intelligence
Data is next Intel inside
End of the software release cycle
Lightweight programming models
Software above the level of a single device
Rich user experiences
- What is Web 2.0 by Tim O’Reilly
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Web browsing privacy
Cookies: small files stored on the user’s hard drive by
a Web server
▪ Add functionality (such as shopping carts and
personal preferences) to Web sites
▪ Can be used to track Web activity
▪ Cookie information can be personally identifiable or
non-personally identifiable
▪ Cookie data can be viewed or deleted
▪ Cookie settings can be changed and software can
be used to manage cookies
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Web browsing privacy, cont’d
Web bugs: small, usually invisible, images on a Web
page that transmits data to a Web server
▪ Difficult to spot or stop
▪ Software can be used to notify you when Web bugs
are
being used
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Web browsing privacy, cont’d
Spyware (transmits data secretly through the user’s
Internet connection)
Adware (software supported by onscreen advertising)
E-mail privacy
Only encrypted e-mail can be transmitted privately
Employers and ISPs have access to the e-mail you send
through those organizations
Businesses and ISPs typically archive e-mail messages
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Very high speed (home fiber optic)
Mobility and portability
Alternative interface
More interactivity
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Evolution of the Internet
Important Internet Protocols
Getting Set Up to Use the Internet
Beyond Browsing and E-Mail
Censorship and Privacy Issues
The Future of the Internet
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