Web technologies and Protocols

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• TOPICS
• Web technologies and Protocols
• HTTP protocols
• HTML Specifications
• The Format of a Web Pages
• The XML and the VRML

Reporters MARLENE P. GUBATON MARIEVEN
PADUA MARICOR MAY A. NAVAL
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THE WORLD WIDE WEB
History of World Wide Web

• 1945

Vannevar Bush writes an article about
photo-electrical- mechanism device
called Memex.

• 1960s

Doug Engelbert prototypes an oNLine System (NLS)
which does hypertext browsing, editing, email
etc. He invented the mouse.
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Ted Nelsen coins the word Hypretext.
Andy van Dam et. Al. build the Hypertext Editing
System.

• 1980

Tim Berners-Lee writes a notebook program
Enquire-WrittenUpon-Everything which allows
links between arbitrary nodes.

• 1989

Tim Berners-Lee write the Information
Management A Proposal which he circulated for
comments at CERN.
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• 1990

TBL starts working on hypertext GUI
browsereditor using the NeXTStep development
environment. He makes up WWW as the name of the
project. Nxo01.cern.ch the first web
server nxo01.cern.ch/hypertext/www/theProject.html
the first website.

• 1991

The release of Line mode browser General release
WWW on central CERN machines VMS/HELP WAIS
gateways installed
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Anynomous telnet service started. Paul Kunz
install first Web server outside of Europe, at
SLAC

• 1992

Line mode browser release 1.1 available by
FTP. Distribution of WWW through CernLib,
including Viola.

• 1993

Midas, Erwise and Viola browsers are
available. NCSA release first alpha version of
Mosaic for X.
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WWW (port 80 HTTP) traffic measures 0.1 of NSF
backbone traffic. CERN declared that WWW
technology would be freely usable by anyone. NCSA
releases working versions of Mosaic browser for
all common platform. WWW receives IMA award.

• 1994

Internet in a box was announce. Mosaic
Communications Corp later know as Netscape was
form.
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The first International Conference was held at
CERN and it was acclaimed as the Woodstock of
the Web. October 1 World Wide Web consortium was
founded. Year of the Web.
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UNDERSTANDING WORLD WIDE WEB
World Wide Web
- is system of Internet servers that support
hypertext to access Internet Protocols on a
single interface.
- its fundamental idea was to merge the
techniques of computer networking and hypertext
into a powerful and easy to use global
information system.
Web page
Are electronic documents that have built-in links
to other related documents.
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Web site
A collection of related web pages.
Home Page is a starting point of websites.
Web browser A software used to access web pages.
Web server
Is a computer and software that delivers
requested web page to the clients browser. It is
where web pages that make up the web are stored.
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Hypertext
Is the text with links to further information, on
the model of references in a scientific paper or
cross references in the dictionary.
Hyperlinks
Allows users to navigate quickly and in a
nonlinear fashion from one page to another with
just one click. Text links appear as underlined
words or phrases, and graphic links are in the
form of images and icons.
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Uniform Resource Locator (URL) - it
specifies the Internet address of a file stored
on a host computer connected to the Internet.
Format of URL protocol//host/path/file
name example http//www.house.gov/agric
ulture/schedule.htm
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Structure of this URL 1. Protocol http
2. Host computer name www 3. Second level
domain name house 4. Top-level domain
name gov 5. Directory name agriculture
6. File name schedule.htm
URLs are translated into numeric addresses using
the Damain Name System (DNS).
Example http//www.rsna.org/ OR
http192.203.125.59/ as the URL
and still visit the same Web page.
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INTERNET PROTOCOLS
Major Protocols available on the Web
Internet Message Access Protocol (IMAP) -
allows the client to access manipulate
electronic mail messages on a server.
File Transfer Protocol (FTP) - currently
used for accessing fairly stable public
information over a wide area.
Network News Transfer Protocol - allows
transient news information in the USENET news
format to be exchanged over the internet.
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POP3 - a protocol that allows one to
retrieve and send mail remotely from a computer
which is running a POP3 client.
KERMIT - a protocol that allows adaptation
to any kind of connection between any two kinds
of computers.
Border Gateway Protocol (BGP) - a protocol
for exchanging routing information between
gateway hosts in a network of autonomous systems.
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Simple Mail Transport Protocol (SMTP) - a
protocol designed to transfer electronic mail
reliably and efficiently.
BitTorrent - a protocol for distributing
files.
Passport Protocol - a protocol that enables
users to sign into many different merchants web
pages by authenticating themselves only once to a
common server.
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1. Request Page
IBM.COM
2. Auto redirect
7. Request page w/ credentials
Browser
8. Set cookie
3. Redirect
4. Request credentials
Passport Server
5. Login password
6. Redirect with tokens in header
The Passport Architecture
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Wallet Protocol - a protocol which is
similar to single signon protocol, instead of
just authenticating, the user can insert all
sorts of personal and card card information.
Address Resolution Protocol (ARP) - is a
protocol for mapping an Internet Protocol address
to a physical machine address that is recognized
in the local network.
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The Hypertext Transfer Protocol (HTTP) - is
a client-server protocol by which two machines
can communicate over a TCP/IP connection. -
it is a protocol used for document exchange in
WWW.
Most common request methods used in HTTP GET
- ask to retrieve a document POST - passes
from data to the server for use as input to some
CGI program HEAD - asks to retrieve only the
HTTP response header for a document but not the
document itself.
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The client side HTTP requests
HTTP requests normally happen on port
80 Example http//perlfect.com/articles/index.s
html
GET / articles/index.shtml HTTP/1.0 User-Agent
Mozilla 4.0 (X I Linux-2.0.35i586 Host
www.perlfect.com Accept image/gif, image/jpeg,
/
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The server side HTTP responses
HTTP/1.0 200 OK Date Thus, 08 Oct 1998 161752
GMT Server Apache/1.1.1 Content-type
text/html Content-length 1538 Last-modified
Mon, 05 Oct 1998 012350 GMT
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Status Code Definitions 2xx Successfu a
class of status code that indicates that the
clients request was successfully receive,
understood and accepted. 200 OK 201
created 202 accepted 204 no content 3xx
Redirection - a status code that indicates
further action needed to be taken by the user
agent in order to fulfill the request. 300
multiple choices 301 moved permanently
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301 moved permanently 302 moved
temporarily 304 not modified 4xx Client
error - status code is intended for cases in
which the client seems to to have erred. 400
bad request 401 unauthorized 403
forbidden 404 not found 5xx Server error
indicates cases in which the server is aware that
it has erred or is incapable of performing the
request.
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500 internal server error 501 - not
implemented 502 bad gateway 503 service
unavailable
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Summary WWW is system of Internet servers that
support hypertext to access several Internet
protocols on a single interface. - it is
invented by Tim Berners-Lee It consist of
webpages that has links called hyperlinks, each
web page has a unique URL that is translated into
numeric address using DNS. Everything that
happens on the web, happens over HTTP
transactions. And the TCP/IP networking and HTTP
are the two essential components that make the
web work.