Windows NT

Windows NT
Once a small and simple collection of computers run by the Defence Department,
is now a massive world wide network of computers, what we call the ‘Internet’.

The word “Internet” literally means “network of networks.” In itself, the
Internet is composed of thousands of smaller local networks scattered throughout
the globe. It connects roughly 15 million users in more than 50 countries a day.

The World Wide Web (WWW) is mostly used on the Internet. The Web refers to a
body of information, while the Internet refers to the physical side of the
global network containing a large amount of cables and computers.


The Internet is a ‘packet-switching’ computer network. When a person sends a
message over the Internet, it is broken into tiny pieces, called ‘packets’.

These packets travel over many different routes between the computer that it is
being sent from to the computer to which it is being sent to. Phone lines,
either fibre-optics or copper wires ones, carry most of the data packets.

Internet computers along the path switch each packet that will take it to its
destination, but no two packets need to follow the same path. The Internet is
designed so that packets always take the best available route at the time they
are travelling. ‘Routers’ which are boxes of circuit boards and microchips,
which do the essential task of directing and redirecting packets along the
network.Much smaller boxes of circuit boards and microchips called ‘modems’
do the task of interpreting between the phone lines and the computer. The
packets are all switched into a destination and reassembled by the destination
computer. Today’s Internet contains enough repetitious and interconnected
circuits simply to reroute the data if any portion of the network goes down or
gets overloaded.


The packet-switching nature of the Internet gives it sufficient speed and
flexibility to support real-time communication, such as sending messages to
other people in a chat environment (IRC). Every packet is written in a
particular protocol language, called TCP/IP, which stands for Transmission
Control Protocol/Internetworking Protocol. This protocol is the common language
of the Internet, and it supports two major programs called File Transfer
Protocol (FTP) and Telenet. FTP lets the transfer files from one Internet
computer to another. Telnet lets a person to log into a remote computer. They
have combined these two tools in complex ways to create the Internet tools such
as Gopher, the World Wide Web and IRC.


Some collections of phone lines and routers are larger and more powerful than
others. Spirit and MCI both have each built collections of phone lines and
routers that crisscross the United States and can carry large amounts of data.

There are six companies in the US with large, nationwide networks of high-speed
phone lines and routers. These companies include, MCI, Sprint, AGIS,
UUNet/AlterNet, ANS, and PSI. They make up what they often call the ‘Internet
Backbone’.


Data packets travelling on a ‘backbone’ network stay within that network for
much of their journey. The reason is that there is only a handful of places
where the backbone networks meet. For example, 1a packet travelling on a Sprint
circuit to a Sprint router, can only transfer to an MCI circuit at certain
places. This is just like how certain city streets often run parrel to each
other for many miles before reaching an intersection. These intersections that
they call ‘Network Access Points’ (NAP) are very crucial to the transmission of
data on the Internet.


A Web is a program running on a computer who’s only purpose is to serve
documents to other computers when asked. A Web client is a program that
interfaces (talks) with the user and requests documents from a server as the
user requests them. The server only operates when a request for a document is
made. The process of how this work is very simple, one example is; Running a
Web browser, the user selects a piece of hypertext connected to another text –
“Planes.”
The Web client connects to a computer specified by a network address somewhere
on the Internet and asks that computer’s Web server for “Planes.” The server
responses by sending the text and any other media within the text (this includes
pictures, sounds, movies) to the users screen. The World Wide Web does
thousands of these transactions per hour throughout the wold, creating a web of
information.


They call the language that the Web client and servers use to talk with each
other the ‘Hypertext Transmission Protocol’ (HTTP). All Web clients and servers
must be able to speak HTTP to send and receive hypermedia documents.


The standard language the Web uses for creating and recognizing hypermedia
documents is the ‘Hypertext Markup Language’ (HTML). Another formatting
language used for Web documents is ‘Standard Generalized Markup Language’ (SGML).

HTML is widely liked because of its ease of use. Web documents are usually
written in HTML and are usually named with the suffix ‘. html’. HTML documents
are nothing more than standard 7-bit ASCII files with formatting codes that
contain information about the layout (text styles, document titles, paragraphs,
lists and hyperlinks). Hyperlinks are links in the document to go to other
documents or another Web sight. HTML uses what they call ‘Uniform Resource
Locators’ (URL) to represent hypermedia links and links to network services
within documents. The first part of the URL (before the two slashes) specifies
the method of access. The second is typically the address of the computer where
the data or service is found. Further parts may specify the name of files, the
port toconnect to, or the text to search for in a database.


Most Web browsers allow the user to specify a URL and connect to that document
or service. When selecting hypertext in an HTML document, the user is actually
sending a request to open a URL. In this way, they can make hyperlinks not only
to other texts and media, but also to other network services.


The powerful, sophisticated access that the Internet provides is truly amazing.

It is spreading faster than cellular phones, and fax machines. The amount of
people connecting to the Internet is growing at a rapid rate, along with the
number of “host” machines with direct connection to TCPIP. The main reason
that the Internet is flourishing so rapidly is because of the freedom, there is
no one who actually owns the Internet and no rules for users. As the Internet
grows, many new activities are joining in, like ‘Internet Radio’, which will
support real-time call-in shows and music to be sent over the Internet. As the
Internet is expanding into another decade, it will become even more interesting
and complex.


FOOTNOTES:
1.John Quarterman, The Matrix: Computer Networks and Conferencing Systems
Worldwide (Bedford, MA: Digital Press, 1990), 42.
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