Transcript The Internet & The World Wide Web

The Internet & The World
Wide Web
Magister Teknik Elektro
Pertemuan II
September 2010
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• Start from Morse Code, then telegraph,
etc.
• The largest network of networks in the
world.
• Uses TCP/IP protocols and packet
switching .
• Runs on any communications
substrate.
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A Brief Summary of the
Evolution of the Internet
First Vast
Computer
Network
Silicon Envisioned
Chip
A
1962
Mathematical 1958
Theory of
Communication
Memex
1948
Conceived
Packet
Switching
Invented
1964
Hypertext
Invented
1965
TCP/IP
Created
ARPANET
1972
1969
Mosaic
Created
WWW
Internet Created
1993
Named
1989
and
Goes
TCP/IP
1984
Age of
eCommerce
Begins
1995
1945
1945
1995
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Copyright 2002, William F. Slater, III, Chicago, IL, USA
Access Device & Physical
Connection
• Bandwidth: volume of data can be
sent/received through a communications
channel in a given amount of time
• bps
• Hertz
• Principal means of connection
•
•
•
•
Telephone (dial-up modem)
Several high speed phone lines: ISDN, DSL, T1
Cable modem
Wireless: satellite, etc.
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Connection
Max Speed
(download)
Notes
Telephone
56 kbps
Inexpensive, easy to get
ISDN
128 kbps
Faster than dial-up, uses
conventional phone lines
DSL
1.5 – 8.4 Mbps
Fast download, always on, higher
security
T1 line
1.5 Mbps
Support many users, reliable high
speed both ways
Cable modem
10 Mbps
Fast, always on, support many
users
Satellite
400 kbps
Wireless, fast, reliable
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• ISDN
• Allows voice, video, data to be communicated over traditional
copper-wire telephone lines
• able to send signals over POTS lines
• xDSL (Digital Subscriber Line)
• Uses regular phone lines with DSL modem
• ADSL, SDSL, HDSL, etc
• T1 line
• A traditional trunk line that carries 24 normal telephone
circuits with transmission rate of 1.5 Mbps
• T3 line transmits at 44 Mbps
• STS-1 runs at 51 Mbps
• STS – 48 connection speeds data along at 2.5 Gbps
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• Cable modem
• Connects PC to a cable TV system that offers an
Internet connection
• Always on
• Sharing the system with the neighbors: slower
(peak load times), more vulnerability (from
hackers)
• Wireless systems
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ISP
• ISP (Internet Service Provider)
• A company that connects you through your
communications line to its servers, which connect
you to the Internet via another company’s network
access points
• Costs
• Access
• Support
• Reliability
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WWW
• Surfing or browsing on the Web and email
are popular use of the Internet
• Multimedia form
– What makes the Web graphically inviting
• Use of hypertext
– What makes the Web easily navigable
– A system in which documents in many
Internet sites are directly link – with hyperlinks
– so that a word or phrase in one document
becomes a connection to a document in a
different place
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– Hyper-Text Markup Language (HTML) : the
set of special instructions that are used to
specify document structure, formatting, and
links to other multimedia documents.
• http://www.unud.ac.id/ind/penerimaan-mahasiswa-baruprogram-studi-hubungan-internasional-dan-sosiologitahun-2009.html
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• Website – domain in the computer
• A computer with a domain name is called a site
• www.detik.com & www.kompas.com
• Web pages – the documents on a website
• A website is composed of a web page or collection
of related web pages
http://nasional.kompas.com/read/xml/2009/
09/17/17215334/Akhir.Pelarian.Sang.Buron
.9.Tahun
• A document on the www that can include text,
pictures, sound, and video
• The first page is like the title page of a book – a
homepage : www.kompas.com or www.unud.ac.id
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• Browsers
• Software for connecting with websites
• Software that enables users to view web pages
and to jump from one page to another
• Microsoft Internet Explorer, Netscape Navigator,
etc.
• URLs – addresses for web pages
• Uniform Resource Locator
• A string of characters that points to a specific piece
of information anywhere on the Web
• Website’s unique address
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• URL consists of
– The web protocol
– The name of the web server
– The directory (folder) on that server
– The file within that directory (.html or .htm)
– http://www.balipost.go.id/keluarga/artikel1.htm
• http:// - protocol: set of communication rules for
exchanging information
• www.balipost.go.id - the web server
• Keluarga – directory in the server
• Artikel1.htm – a file in html
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• Be careful do browsing
– Know the source
• www.internic.net use the Registry Whois link to
search the database of registered domain names
• InterNIC—Public Information Regarding
Internet Domain Name Registration Services
– A tilde (~)
• Usually a sign of a personal site – run by an
individual
• E.g. http://staff.unud.ac.id/~linawati
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• Web portals
– Websites that group together in one
convenient location popular features such as
search tools, email, electronic commerce, and
discussion groups
• Yahoo, altavista, lycos, etc.
• http://www.unescobkk.org/
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• Multimedia on the web
– Plug-ins
• External application files had to be loaded into the
system
• Or is called a player or a viewer
• E.g. Acrobat Reader, Flash Player, Media Player,
Quick Time, etc.
– Developing multimedia – applets, Java,
JavaScript, and ActiveX
– Streaming video / audio
• The process of transferring data in a continuous
flow so that you can begin viewing / listening a file
even before the end of the file is sent.
• Realplayer, RealAudio, etc.
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• Push technology & webcasting
– Push technology, software that automatically
downloads information to your computer
• E.g. updating software or antivirus application
– Webcasting (one result of push technology)
• Customized text, video, and audio are sent to you
automatically on a regular basis
• Webcast, webinars, livestreaming, flashstreaming,
webconference, etc.
• A webcast is a way of broadcasting over the
Internet — analogous to a broadcast television
program.
• The primary purpose of a webcast is to transmit
a message to a large number of people
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• Web conferences
– used to conduct live meetings or presentations where
you can sit at your own computer and can connect to
other participants via the Internet.
• A webinar
– a specific type of web conference — a web-based
seminar.
– It is typically one-way, from the speaker to the
audience.
– can be very collaborative and include polling and
question and answer sessions.
– In some cases, the presenter may speak over a
standard telephone line, pointing out information
being presented on-screen and the audience can
respond over their own telephones
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• The Internet Telephone & Videophone
• Audio conferencing
• Video conferencing
• Other Internet applications
• FTP (file transfer protocol)
– A method whereby a computer can connect to a remote
computer and transfer files
– E.g. smartFTP, cuteFTP, etc.
• Telnet
– A program that enables user to communicate with other
computers and is typically used for remote access to host
computers on which user has an account
• Newsgroups
• RTC (real-time chat)
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Software Services
• Archie
• A collection of resource discovery tools, developed and
maintained by McGill Univ, for locating files at hundreds of
anonymous FTP sites by using a file name search
• Gopher
• combines features of electronic bulletin board services and
databases with parts of FTP, Archie, WAIS, and Telnet into
one easy-to-use navigation tool.
• It simplifies locating and retrieving ASCII text documents from
various sources of information
• Veronica (Very easy rodent-oriented net-wise
index to computerized archives)
• Service that locates and indexes titles of Gopher items by
keyword search. A veronica search typically searches the
menus of hundreds of Gopher services, perhaps all the
Gopher servers that are attached to the Internet
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• WhoIs
• Provides information on registered users and network
names, including their postal addresses. The main WhoIs
database runs at the Network Information Centre (NIC)
with administrative and technical contacts for domains
automatically registered when the applications are
processed.
• WAIS
• Wide Area Information Server
• a client – server system developed to help users search
multiple Internet sites at one time and retrieve resources by
searching indexes of databases.
• WWW
• World Wide Web retrieves resources as a powerful
hypertext and hypermedia browser of databases. Hypertext
is text with pointers to other text. Hypermedia might also
involve images, sound, or animation, in addition to text.
• This public domain software goes beyond Gopher and WAIS
as a global information system with an easy-to-use interface
that provides access to almost all existing Internet-based
information. The information appears on homepage.
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• HTML
• HyperText Markup Language is one of the capabilities that
is used like a word processor to create a WWW homepage.
• Is a language, a standard for creating multimedia, hypertext
files, and a standard for serving these standardized files
when they are requested.
• HTTP
• HyperText Transfer Protocol is the standard used by the
server and its clients, which will send HTML files over the
Internet from the server to clients requesting them.
• http:// on the WWW to access a homepage, that is, a site with
HTML documents
• Mosaic
• A hyperlink – based Internet information browser and world
wide web client that provides transparent access to a number
of resources, including anonymous FTP, WAIS, and WWW.
• Netscape
• A premier graphics and hyper-based Internet information
presenter and browser, similar to Mosaic. One feature is the
access to search engines.
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• Explorer
• Microsoft cooperation’s competitor to Netscape
• Java
• A simple, object-oriented, distributed, interpreted,
robust, secure, architecture neutral, portable, highperformance, multithreaded, and dynamic
language.
• Etc
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Jargons on Internet
• Browser
• Software that opens the door of the web, allowing
the display of text and graphics
• FAQ
• Frequently asked questions: a grab bag of
questions that new users of a web site often ask –
with answers, of course
• Hit
• A rough measure of a site’s popularity; each hit
represents one time that a file in the site is
accessed
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• Homepage
• The opening screen of a web-site
• Hypermedia
• Video and sound files transmitted by way of the Web
• Hypertext
• Highlighted text linked to related pages in the same or other sites
• Search engine
• An electronic directory on the web that search for documents,
pages, or sites based on a keyword
• Website
• A collection of pages and files on the Web built around a common
theme or subject
• Webmaster
• The authority figure responsible for maintaining and updating the
information of a site
• URL
• Universal Resource Locater is the technical name of a web address
– http://www.apple.com is an example
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E-mail
• Email software
• Eudora, Outlook Express, Lotus Notes
• Email address
•
•
•
•
A domain: a simple a location on the Internet
E.g. [email protected]
Unud.ac.id  domain name
Unud  domain (location), ac  domain type, id
 country
• Check on whether the address is available, as
well, and register it by going to www.register.com
or www.internic.net/regist/html
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• Instant messaging
• Any user on a given email system can send a
message and have it pop up instantly on the
screen of anyone else logged onto that system
• Typed conversations in real time
• Yahoo Messenger, MSN Messenger, etc.
• Mailing list
• Email based on discussion groups
• To be a member – subscribing & unsubscribing
• A directory of mailing lists is available at Publicly
Accessible Mailing Lists (http://paml.net) or
Yahoo!’s OneList (www.onelist.com)
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Netiquette: appropriate online
behavior
• Consult FAQs
• Avoid flaming
• Flaming is a form of public humiliation inflicted on people who have
failed to read FAQs or otherwise not observed netiquette.
• Don’t shout
• Avoid use of all-capital letters. It is considered the equivalent of
SHOUTING
• Avoid sloppiness, but avoid criticizing other’s sloppiness
• Such as avoid spelling and grammatical errors
• Don’t send huge file attachments, unless requested
• Different bandwidth, capacity, and storage
• When replying, quote only the relevant portion
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• Some emoticons
–
–
–
–
–
–
–
–
–
Happy face :-)
Sorrow or frown :-(
Shock :-o
Sarcasm :-/
Wink ;-)
Grin <g>
By the way BTW
In my humble opinion IMHO
For your information FYI
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• Spam : unwanted junk email
– Delete without opening the message : virus
– Never reply to a spam message
– Enlist the help of your ISP or use spam filters
• E.g. Earthlink’s Spaminator
• ImagiNet (www.imagin.net) , www.brigthmail.com,
www.spamkiller.com, www.hms.com
– Fight back
• Report to (www.abuse.net) , www.rahul.net/falk
• These will tell you where to report spammers, the
appropriate people to complain to, and other
spam-fighting tips
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