Telecommunications

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Transcript Telecommunications

Chapter 7
The Internet and the
World Wide Web
The Internet:
A Global Network
Besides communications, the Internet can
also be used for research, distance learning,
entertainment, and e-commerce. Search
engines can be used to conduct research.
Computers can be used for
entertainment purposes, including
playing games, listening to music, and
even viewing movies and videos
Electronic Commerce
(E-commerce)
Refers to the Internet
exchange of business
information, products,
services, and payments.
Categories of E-commerce
E-commerce is commonly divided into two
categories defined by target audience
Business-to-consumer (B2C)
Business-to-business (B2B).
Internet Service Provider ( ISP)
ISP Office
An Internet service provider (ISP)
is a company that provides
Internet access.
Value Added
Networks (VANs)
Large ISP companies that provide a connection to
the Internet as well as additional content.
Connecting to the Internet
There are two main ways for
users to connect to the Internet:
through dial-up access
LAN connection
High-speed options include cable,
digital subscriber line (DSL),
wireless, and satellite connections
Navigating the Internet
To access and move
about the Web,
users need to know
how to navigate
using a browser.
Meta Browsers
Favorites
Yahoo
MSN
Netscape
CNN
Google
Allow users to put all their
favorite sites onto one page.
Internet Protocol
(IP) Addresses
Web browsers locate material on the
Internet using
Internet protocol (IP) addresses.
Uniform Resource Locator (URL)
Every IP also has a
corresponding Web address
called a Uniform Resource
Locator (URL).
(URL) is a pathname describing where
the information can be found.
Packets
The Internet breaks files into many
pieces of data, called packets.
P1
P2
P3
Packet-Switching
The Internet sends packets out over
separate routes, a process called packetswitching.
P3
56k
P1
ROUTER
28.8k
P2
DSL
P1
P2
P3
A Web Page
A single document
viewable on the
World Wide Web.
A Web Site
Links to
other
pages
of site.
Includes all of the Web pages
comprising the site.
Home Page
The first page displayed
after a Web site is
accessed is usually the
site’s home page.
Hyperlink
Click Here to see next slide.
A Web link, or link is any element on the screen
that is coded to transport viewers to another
page or site.
(HTML)
Web pages are usually created
using hypertext markup
language (HTML).
Extensible Markup
Language (XML)
A new and improved Web language that allows computers
to communicate with each other directly.
JAVA
<script language="JavaScript">
<!-function MM_swapImgRestore() { //v3.0
var i,x,a=document.MM_sr;
for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;
}
function MM_preloadImages() { //v3.0
var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();
var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0;
i<a.length; i++)
if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image;
d.MM_p[j++].src=a[i];}}
}
}
//-->
</script>
Web site designers
frequently program
using Java and Java
applets.
A plug-in
A miniprogram that extends
the capabilities of Web
browsers in a variety of ways.
Ways Companies Advertise
on the Internet
WebRings
Linked sites
devoted to a
similar theme
or topic.
Searching for Information
on the Internet
Searches are conducted using
keywords (search terms).
Advanced searching requires the use of logic
statements known as search operators to
refine searches and improve results.
Peer-to-Peer (P2P)
File Sharing
Allows people to download
material from other users’
hard drives.
Internet Telephone Services
Provide free long-distance service.
Streaming Techniques
An alternative to downloading a video
file is to access it using streaming
techniques (also known as
Webcasting).
Webcams
Tiny video cameras called webcams allow
conversations over the Web through live
video transmission.
Free E-mail
E-mail services work by using a
Web browser as an e-mail interface.
Audio Mail
Allows people to transmit not only text and pictures but
also a recording of their voice.
Internet Community Issues
Flaming is one of the most frequently
encountered examples of rude
Internet behavior.
Guidelines for good behavior, called netiquette,
encourage people to interact productively
Moderated environments are another
solution to inappropriate behavior.
Internet Policy
Developers have not reached an agreement on a
common communications standard.
Incompatible standards mean that businesses and
consumers are inconvenienced, and the full potential
of the application is not realized.
Internet Policy
Development Issues
Limited bandwidth in many areas slows down transmissions
speeds, especially with the huge multimedia files that are
increasingly common.
More Internet Policy
Development Issues
Privacy and security are major concerns in
e-mail communications and e-commerce
transactions.
Encryption systems can protect
customers’ financial information.
Viruses
Computer viruses represent a significant
threat to all computer systems.
To eliminate the threat, virus scanning
software is widely available.
The Digital Millennium
Copyright Act of 1998
Copyright law violations are frequent
occurrences on the Internet.
The DMC Act of 1998
Generally prohibits people from
defeating software encryption programs
and other safeguards that copyright
holders have established to control
access to their works.
On the Horizon
Satellite Internet Connections
Remote ISPs connect to the satellite network using antennae attached
to their servers. Data is relayed to and from ISP servers to satellites,
which are, in turn, connected to an Internet backbone access point.
Another Internet?
A remedy for the traffic clogging the information highway is Internet2, a
revolutionary new type of Internet currently under development.
XML-Based Web Services
Web services are integrated Web-based applications using the new XML
Web language. XML is used to structure data interchange for better
information sharing.
Bring Your Own Access: Internet Services for a Fee
Industry observers, including the research firm Forrester, predict that large
portals will soon determine effective structures and marketing strategies to
get consumers to pay for Internet services.