Transcript Internet

HIMA 4160
Fall 2009
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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.
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1962: Paul Baran proposed the packet switching idea.
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1968 - DARPA (Defense Advanced Research Projects Agency) contracts with BBN
(Bolt, Beranek & Newman) to create ARPAnet
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1970 - First five nodes:
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UCLA, Stanford, UC Santa Barbara U of Utah, and BBN.
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1972 – First email program was created by Ray Tomlinson
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1974 - TCP specification by Vint Cerf
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1981 – NSF created CSNET
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1983 – Domain Name System (DNS) was created
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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
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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.
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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
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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.
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POP
 Post Office Protocol (POP)
 Retrieve email from remote server using TCP/IP protocol.
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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
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 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
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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
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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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