1.7  NET ORIGINS


In the 1960s, researchers began experimenting with linking computers to 
each other and to people through telephone hook-ups, using funds from the 
U.S Defense Department's Advanced Research Projects Agency (ARPA). 

ARPA wanted to see if computers in different locations could be linked 
using a new technology known as packet switching. This technology, in 
which data meant for another location is broken up into little pieces, 
each with its own "forwarding address" had the promise of letting several 
users share just one communications line.  Just as important, from ARPA's 
viewpoint, was that this allowed for creation of networks that could 
automatically route data around downed circuits or computers.  ARPA's 
goal was not the creation of today's international computer-using 
community, but development of a data network that could survive a nuclear 
attack. 

Previous computer networking efforts had required a line between each 
computer on the network, sort of like a one-track train route. The packet 
system allowed for creation of a data highway, in which large numbers of 
vehicles could essentially share the same lane.  Each packet was given 
the computer equivalent of a map and a time stamp, so that it could be 
sent to the right destination, where it would then be reassembled into a 
message the computer or a human could use. 

This system allowed computers to share data and the researchers to 
exchange electronic mail, or e-mail.  In itself, e-mail was something of 
a revolution, offering the ability to send detailed letters at the speed 
of a phone call. 

As this system, known as ARPANet, grew, some enterprising college 
students (and one in high school) developed a way to use it to conduct 
online conferences.  These started as science-oriented discussions, but 
they soon branched out into virtually every other field, as people 
recognized the power of being able to "talk" to hundreds, or even 
thousands, of people around the country. 

In the 1970s, ARPA helped support the development of rules, or protocols, 
for transferring data between different types of computer networks.  
These "internet" (from "internetworking") protocols made it possible to 
develop the worldwide Net we have today that links all sorts of computers 
across national boundaries. By the close of the 1970s, links developed 
between ARPANet and counterparts in other countries.  The world was now 
tied together in a computer web.  

In the 1980s, this network of networks, which became known collectively 
as the Internet, expanded at a phenomenal rate.  Hundreds, then 
thousands, of colleges, research companies and government agencies began 
to connect their computers to this worldwide Net.  Some enterprising 
hobbyists and companies unwilling to pay the high costs of Internet 
access (or unable to meet stringent government regulations for access) 
learned how to link their own systems to the Internet, even if "only" for 
e-mail and conferences.  Some of these systems began offering access to 
the public. Now anybody with a computer and modem, persistance and a 
small amount of money -- and persistence -- could tap into the world. 

In the 1990s, the Net continues to grow at exponential rates.  Some 
estimates are that the volume of messages transferred through the Net 
grows 20 percent a month.  In response, government and other users have 
tried in recent years to expand the Net itself.  Once, the main Net 
"backbone" in the U.S. moved data at 56,000 bits per second. That proved 
too slow for the ever increasing amounts of data being sent over it, and 
in recent years the maximum speed was increased to 1.5 million and then 
45 million bits per second. Even before the Net was able to reach that 
latter speed, however, Net experts were already figuring out ways to pump 
data at speeds of up to 2 billion bits per second -- fast enough to send 
the entire Encyclopedia Britannica across the country in just one or two 
seconds.  Another major change has been the development of commercial 
services that provide internetworking services at speeds comparable to 
those of the government system.  In fact, what started as a government 
experiment is now largely a private enterprise.