Transcript Routers

The Internet and Web
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Please discontinue use of cell
phone and turn off ringer
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Internet Technology
Internet Communications
Web technology
Web Applications
4.1
Internet Technology
What is the Internet?
Key Terms
• Internet Backbone
• Internet Service Provider
(ISP)
• Routers
• Dial-up Connection
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• Cable modem
connection
• DSL connection
• DSS connection
• Protocols
• TCP/IP
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IP Address
Client/server
Port
Peer-to-peer (P2P)
What is the Internet?
Visualization of the Internet’s topology from
http://www.cybergeography.org/atlas/topology.html
A Brief History of the Internet
http://www.zakon.org/robert/internet/timeline/
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Let’s start with the movie
 Warriors on the Web
 The Players:
 IP
 Packet
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Different kinds
Different sizes
Proxy server
Router
Switch
Network interface
Firewall
Web server
Ping of death
LAN
Internet
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Ethernet Network
The original Ethernet described communication over a single
cable shared by all devices on the network. Once a device
attached to this cable, it had the ability to communicate with any
other attached device.
Each Ethernet devices has a unique address.
The Ethernet protocol specifies a set of rules for communication.
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Network Interface Cards (NIC)
The computer gives the NIC a message for another networked device and
the NIC formats that message for transport over the Ethernet. The
reverse is also true, the NIC receives messages from the network and
reformats them so that the computer can understand.
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Ethernet Frame
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Switched Ethernet
A switch creates a series of instant networks that contain only the two
devices communicating with each other at that particular moment.
Switches maintain their own Medium Access Control (MAC) look-up
tables. These table indicate which network device is at which port
on the switch. The look-up tables are constantly updated. When a
switch is newly installed, it will construct its table via an Address
Resolution Protocol (ARP) broadcast.
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Local Area Network (LAN)
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Routers
To connect two networks you need a Gateway or a Routers
Routers are devices that let messages flow between networks
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Routers
 A router uses a configuration table to
determine where packets go. A
configuration table is a collection of
information, including:
 Information on which connections lead to
particular groups of addresses
 Priorities for connections to be used
 Rules for handling both routine and
special cases of traffic
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IP Address
 Each machine on the Internet is
assigned a unique address called an
IP address. IP stands for Internet
protocol, and these addresses are 32bit numbers, normally expressed as
four "octets" in a "dotted decimal
number."
 Example:
216.27.61.137
 Every machine on the Internet has a
unique IP address.
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Names
 People have trouble remembering IP
addresses. All servers on the Internet
also have human-readable names, called
domain names.
 A set of servers called Domain Name
Servers (DNS) maps the humanreadable names to the IP addresses.
These servers are databases that map
names to IP addresses; they are
distributed all over the Internet.
 Example:
www.howstuffworks.com for 209.116.69.66
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Network
Addresses
Most switches operate at the Data
layer (Layer 2) of the OSI Reference
Model, while routers operate at the
Network layer (Layer 3)
When a router receives a packet,
it looks at the Layer 3 source
and destination addresses to
determine the path the packet
should take. A standard switch
relies on the MAC addresses to
determine the source and
destination of a packet, which is
Layer 2 (Data) networking.
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Open Systems Interconnection (OSI) standard
Application Set
Layer 7: Application - Layer that
interacts with the operating system or
application whenever the user chooses
to transfer files, read messages or
perform other network-related
activities.
Layer 6: Presentation - Takes the data
provided by the Application layer and
converts it into a standard format that
the other layers can understand.
Layer 5: Session - Establishes,
maintains and ends communication
with the receiving device.
Transport Set
Layer 4: Transport - Maintains flow control of data and provides for
error checking and recovery of data. TCP layer
Layer 3: Network - Logical routing and addressing. IP layer
Layer 2: Data – Assigns the appropriate physical address.
Layer 1: Physical - This is the level of the actual hardware.
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Internet Protocols
 Protocols are rules that govern how data is
transmitted and received.
 They govern all Network and Internet
communications:
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The Internet
The Web
Email
Instant Messaging
Etc.
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Ports are numeric addresses
assigned to specific network
services, and used in packet
headers to direct data packets to
the appropriate service. See
http://en.wikipedia.org/wiki/List_of_T
CP_and_UDP_port_numbers
Internet Protocols
 TCP/IP
 Transmission Control Protocol (TCP): Divides data into
packets for transmission, and reassembles data from
packets upon delivery.
 Internet Protocol (IP): Controls the delivery of packets
between IP addresses.
 IP Address
 a 32-bit number that identifies each sender or receiver of
information that is sent in packets across the Internet.
 10000000.11111111.10110101.00010111
 128.255.181.29
 www.fsu.edu
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Protocol Layering and Data
 Each layer takes data from above
 adds header information to create new
data unit
 passes new data unit to layer below
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Clients and Servers
Any server machine makes its
services available to the Internet
using numbered ports, one for
each service that is available on
the server.
Logical port numbers
correspond to
application layer
programs.
These port numbers
are included in the
address information
of a packet.
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Here are some common port numbers:
•echo 7
•daytime 13
•qotd 17 (Quote of the Day)
•ftp 21
•telnet 23
•smtp 25 (Simple Mail Transfer, i.e., e-mail)
•time 37
•nameserver 42
•nicname 43 (Who Is)
•gopher 70
•finger 79
•WWW 80
Packet Switching
 A packet switching network divides all
network data into small packets for faster,
more efficient delivery.
An email message
Dear Joan,
Hi! How’s it goin’? Just finished midterms, and it looks like I
might graduate this semester after all! :-) My computer
teacher is really great and I guess that I learned more than
I thought in those wonderful lectures that I had previously
written you about….
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Packet Switching
Divided into packets
Dear Joan,
Hi! How’s it goin’? Just finished midterms, and it
looks like I might graduate this semester after all! :-) My
computer teacher is really great and I guess that I
learned more than I thought in those wonderful lectures
that I had previously written you about….
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Packet Switching
Packet headers added
Dear Joan,
Hi! How’s it goin’? Just finished midterms, and it
Message 3761HZA Date May 1
Packet 1 of 3
From [email protected]
To [email protected]
looks like I might graduate this semester
after all! :-) My computer teacher is really
great and I guess that I
Message 3761HZA Date May 1
Packet 2 of 3
From [email protected]
To [email protected]
learned more than I thought in those
wonderful lectures that I had previously
written you about….
Message 3761HZA Date May 1
Packet 3 of 3
From [email protected]
To [email protected]
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Packet Switching
Each packet sent individually over the network
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Packet Switched Network
Router
Router
Router
Router
Router
Router
Router
Router
Router
email
Router
Router
Router
Router
email
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Router
Router
Firewall
 A firewall is a program or device that
filters the information coming through
the Internet to your private network or
computer system. It can restrict
access of packets based on:
 The designated port
 The IP address
 The packet content or characteristics
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Proxy Server
 Often combined with a firewall
 A proxy server is a program that acts as an
intermediary between computers on your LAN
and computers on the Internet.
 Computers on your LAN request data (like
web pages) from the proxy server to access
the internet. The proxy server then fetches the
internet data, checks it’s filters, and returns it
to the computer that requested it.
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Internet Hardware
 The Internet backbone consists of the
main pathways and connections of the
Internet owned primarily by telecom
companies.
Verizon’s/MCI’s UUNet carries 28% of Internet traffic
http://en.wikipedia.org/wiki/Internet_backbone
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Internet Hardware
 Network Service Providers
 Major telecom
companies that provide
the Internet backbone.
Network Service
Providers
27.9%
Verizon/MCI/UUNET
10.0%
AT&T
6.5%
Sprint
6.3%
Genuity (level 3)
4.1%
PSINet
3.5%
Cable & Wireless
2.8%
XO Communications
2.6%
Verio
1.5%
Qwest
http://navigators.com/isp.html
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Internet Hardware
 Points of Presence (POPs)
 Facilities provided by Network Service Providers
that allow users to connect to the Internet
backbone.
 Internet Service Providers
 Companies that provide users with access to the
Internet.
 Dial-up vs. DSS vs. Cell vs. DSL vs. Cable
Top 22 ISP’s:
http://www.isp-planet.com/research/rankings/usa.html
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4.2
Web Technology
What is the Web?
Key Terms
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Hyperlink
HTTP
Web browser
Web server
URL
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HTML
XML
XHTML
Web authoring software
Cookies
• Plug-in
• Content Streaming
What is the World Wide
Web?
 The web is an application running on the Internet
 It represents many concepts:
 the idea of boundless information interconnected by
hypertext links --- point-and-click access;
 the Uniform Resource Identifier (URI) concept, an
addressing system that makes hyperlinks possible despite
many different protocols;
 the Hypertext Transfer Protocol (HTTP), a network
protocol used to transfer web pages;
 the Hypertext Markup Language (HTML) a content
formatting framework that every WWW client can
understand,
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The Web
 The World Wide Web is an Internetbased service that provides convenient
access to information through
hyperlinks.
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Web Protocols & Standards
 HTTP: Hypertext Transfer Protocol defines
and controls communication between Web
server and client (Web browser).
 URL: Uniform Resource Locator is the
fancy name for a Web address.
http://www.cengage.com/coursetechnology/swt3/topics.html
Domain name
http://www.icann.org/
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Web Protocols & Standards
 HTML: Hypertext Markup Language is the
formatting language used to define the
appearance of Web pages.
 Try View Source in IE
 XML: New and popular standard for
describing and classifying data in Web
pages and other Web services.
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Web Protocols & Standards
 Many of today’s
popular applications
store files in XML
format for easy data
sharing.
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Inventory.xml
Catalog.xhtml
Design.css
Web Server
A complete XML example
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Web Client
Programming the Web
 Cookies are data generated by a Web
server, and stored on your computer.
 Used to target marketing or customize a
webpage when you next visit the server.
Demo
www.amazon.com
IE/Tools/Options/Settings/
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Web Browser Plug-Ins
A plug-in is a program that works with
the browser to offer extended services
–typically the ability to view animations
or video, listen to music, or interact with
the Webpage.
Popular plug-ins include Flash and
Quicktime.
Demos:
http://harrypotter.warnerbros.com
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Web Browser Plug-Ins
 Content streaming allows media files to play
while they are being delivered by the Web
server.
www.movies.com
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4.3
Internet and Web
Applications
How are they used?
Key Terms
• Search engine
• Synchronous
communication
• Asynchronous
communication
• E-mail
• E-mail attachment
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Instant messaging (IM) • Video Conferencing
Chat
• Telecommuting
SMS Text messaging
Blogs
Web 2.0
Wiki
Social Bookmarking
The Internet & Web
Communications
The Web
E-commerce
Information
Distribution
The Internet
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Communication and
Collaboration
RSS (Really Simple
Syndication) A webcontent distribution
technology
 Blogs (Web logs) are websites created to express
one or more individual’s views on a given topic (ie.
http://www.bloglines.com/topblogs)
 A blog aggregator is software that allows you to subscribe
to numerous blogs (ie.
http://www.bradsoft.com/feeddemon/)
 A Podcast is an audio file that contains a recorded
broadcast distributed over the Internet for use on
PC or Mobile media device.
 Podcast Aggregator: provides access to podcasts that
may be set to automatically download to your PC (iTunes).
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Web 2.0
 The collaborative, social Web
 The Web as a computing
platform
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Social Networking - Web sites that provide tools allowing members
to share information about themselves with other members and find
others with similar interests.
Wiki - A Web site designed to allow users to add, remove, and edit,
content.
Social Bookmarking - Provide a way for members to store, classify,
share, and search Web bookmarks.
Media Sharing - Web sites that allow members to share video, music, and
photos, with others.
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Web 2.0 The Social
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Facebook (social net), www.facebook.com
MySpace (social net), www.myspace.com
LinkedIn (pro social net), www.linkedin.com
Digg (news, bookmarking), www.digg.com
Delicious (bookmarking), www.delicious.com
Wikipedia (crowdsourced encyclopedia), www.wikipedia.com
Epinions (consumer reviews), www.epinions.com
Flickr (photo sharing), www.flickr.com
SmugMug (photo sharing), www.smugmug.com
YouTube (video sharing), www.youtube.com
Second Life (3D social net), www.secondlife.com
Plaxo (aggregator), www.plaxo.com
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Web 2.0 Blog Micro-blog
* WordPress, www.wordpress.com
* Blogger, www.blogger.com
* Twitter, www.twitter.com
* Jaiku, www.jaiku.com
* Pownce, www.pownce.com
* Plurk, www.plurk.com
* Spoink, www.spoink.com
* Swurl, www.swurl.com
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Web 2.0 Rich Internet
Apps (RIA)
•Google Docs (productivity apps), http://docs.google.com
•37signals (personal info mng), www.37signals.com
•Zoho (variety), www.zoho.com
•FlyPaper (presentations), www.flypaper.com
•SlideRocket (presentations), www.sliderocket.com
•icloud (web-based OS), www.icloud.com
•eyeos (web-based OS), www.eyeos.com
•Buzzword (word process), www.buzzword.com
•todoist (to-do list), www.todoist.com
•Photoshop Express (photo editing),
www.photoshop.com/express
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4.4
The Future Internet
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The Future Internet
 Internet2 is a research and development
consortium led by over 200 U.S.
universities and supported by
partnerships with industry and
government to develop and deploy
advanced network applications and
technologies for tomorrow’s Internet.
 The National LambdaRail (NLR), or
Internet3 is a cross country, high-speed
fiber-optic network dedicated to
researching high-speed networking
applications.
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High-Speed Internet
Applications
 Interactive Collaboration
Long distance collaboration and
education.
www.accessgrid.com/
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Two dancers in different locations
dance together.
High-Speed Internet
Applications
 Real-time access to remote Resources
Scientists can control the astronomical telescopes at Gemini
observatories in Hawaii and Chile from any location on
Internet2.
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High-Speed Internet
Applications
 Large-scale Multisite Computation and
Data Mining
 Shared Virtual Reality
Consider the future of
www.secondlife.com
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Chapter 4 Questions?
Don’t forget to turn
your phone on!!
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