The Best Internet Programs/BESTINTERNET.bin/internet/lrn_inet/li_inet.txt

Text File | 1994-07-19 | 12.3 KB | 452 lines

 The Superhighway

You've heard the latest buzzword -- the superhighway --
as in "INFORMATION SUPERHIGHWAY."  But what is it?
        -- Where does it go?
        -- Why would you want to go there?
        -- How do you get on?
        -- Is it hard to learn?

If you think these questions are speculative -- about some
futuristic, high tech computer links that are far away and
don't matter anyway...  You're wrong!

In many respects the future is now.

 The Infrastructure

It is true the superhighway's infrastructure has yet to be
built.  That is what the NII (National Information Infra-
structure) and NREN (National Research and Education Net-
work) are all about.  It is also true that the software to
make it easy and convenient to use needs a lot of work.
But when the links are all made and the software all dev-
eloped, what you will be able to do, say and see will not
be much different from what you can do, say and see now on
the Internet.

The future of global communications is now because the
future is the Internet.

 The Internet

The Internet is a huge, interconnected network of networks
involving hundreds of thousands of computers and millions
of users.  According to Harley Hahn, author of _The Inter-
net Complete Reference_ the Internet is:
  "...by far, the greatest and most significant achievement"
   in the history of mankind."
                                    -- ?!?!?!

Hyperbole aside, the Internet is a powerful resource which
allows all sorts of information access, like...



 What You Can Do With It

        -- You can log in to most of the world's libraries.
        -- You can send email to your global colleagues.
        -- You can join automated, special interest mailing
           lists and newsgroups and learn the latest.
        -- You can search worldwide databases and obtain
           documents.
        -- You can get tons of useful software, free!
        -- You can be part of live, discussion groups or
           on-line classes .

All this heady, superhighway stuff comes with your Internet
account.  But...

 The Bad News

Continuing with the superhighway metaphor:  the bad news
is the on-ramp (learning curve) to the superhighway is
steep, and if you haven't yet learned to drive (navigate
the net) you're going to become--

        -- roadkill.

Actually the analogy to driving is a good one.  Learning
the internet is like learning to drive a stick shift car
(your computer and modem) and also learning the rules of
the road (the Internet's various systems).


 The Good News

Don't be discouraged if it seems very difficult at first.
There is a lot to look forward to.  Remember how exciting
it was to learn to drive a car?  Why did you want to learn?

        -- To get away from your parents.
        -- To "move up" in the world.
        -- To go interesting places.
        -- To get a job.
        -- To find out about how things really are.
        -- To broaden your horizons.



 The Problem

When you learned to drive, the problems were:

        * You had to have a car.
        * You had to learn in traffic.

Fortunately, you already have an Internet car (a modem
and the computer that powers it), and you're not likely
to kill anyone while learning.  You'll learn your super-
highway driving skills by using this tutorial.  All you
need now are an Internet connection and a bold and adven-
turous spirit...


 Rev Your Engine

The superhighway...  The final frontier...

If you're ready to go boldly where lots of interesting
people go all the time, then fasten your seatbelt, flip
your turn signal, put her in gear, and get ready to go...






































 Cyberspace

The Internet brings the notion of cyberspace to reality.
In a nutshell, cyberspace means that a computer halfway
around the world is no farther away than a computer at the
next desk.  The links are transparent to the user and
except for slowdowns caused by heavy traffic, access times
are not a factor either.

To get an idea of how this works, follow the flowchart
around the screen during this lesson...




 Making Connections
The thing that makes the internet work are a complicated
set of instructions called protocols.  The internet uses a
whole suite of them, named for their two most important
members: Transport Control Protocol and Internet Protocol,
or TCP/IP for short.  These are sets of rules for moving
about electronic data in packets and making sure they get
reassembled properly when they reach their destination.
Every computer on the Internet speaks TCP/IP.

Your internet connection may be on a computer already
wired directly to a TCP/IP network, so you don't have to
dial in, but for this lesson, lets suppose we have to dial
in to a TCP/IP computer via modem in order to connect...

 The Host Computer

You dial in by instructing your modem (through your com-
munications program) to dial your Internet host computer's
modem.  You will have to go through a device called a
router and a set of login routines to reach your Internet
host.  Once you are connected, your home or office computer
becomes simply another terminal on the host's network (by
use of a terminal emulation program -- once again, part of
your communicatons program).  Although since you are limited
to the speed of your modem, this connection isn't as fast as
a direct TCP/IP connection.



 Unix

To your dismay (unless you are very unusual) you will
discover that your host computer is running an operating
system called Unix.  Once you log in, you will see nothing
more helpful than a blank screen with a little $, or a %,
or maybe a prompt that looks like: [efudd@slowpoke].

The first thing you need to know about Unix is that it is
terse (translate: user unfriendly -- real unfriendly).  The
second thing about Unix is "No news is good news."  If you
run a program and the system doesn't collapse, Unix will
generally say nothing at all.  It speaks up when there is
trouble...

 Around the World In 80 Milliseconds
Though Unix is hard to work with, there are some wonderful
programs written for Unix which make accessing the Internet
if not easy, at least manageable.  One of them was written
at the University of Minnesota and is called "Gopher."  It
is a system of menus that transparently links computers and
databases around the world and makes it possible to easily
locate files, mail them to yourself (or others), download
them, or simply browse about for information.

For purposes of our lesson, let's suppose we want to use the
gopher program to locate a copy of Shakespeare's Hamlet.  We
know that there is a huge virtual library at Geneva, so we
dial in...

 Exploration

A little poking around at CERN near Geneva, Switzerland
reveals that there is a copy of Hamlet kept in a historical
archive at the University of Kansas.  We choose this from
our gopher menu, and it transparently connects us ( a
process called telnetting).  The gopher program at Kansas
looks and behaves just like the one at Cern and on our
host computer, except the menus are different.  After
further gopher digging (!), we locate Hamlet and ask
gopher to mail it to ourselves.  Gopher transparently uses
the Simple Mail Transport Protocol (SMTP) to send the text
of Hamlet back to our host computer....


  Eureka

When we exit gopher and return to the Unix prompt, we decide
to run the mail program, which on our host computer is
called Pine.  Once we start pine we see among our email that
the University of Kansas gopher has indeed mailed us the
complete text of Hamlet.  We decide to export the file to
our Unix home directory and then download it using Unix and
our communications program.  We're back at square one,
having achieved the goal of our quest!





 Pretty Simple

Pretty simple, huh?  Well, not really.  But in fact it is
vastly more complicated than the preceding description makes
it sound.  The Internet uses a transport strategy called
dynamic rerouting, which means that the packets sent may
travel different routes and pass through many different
computers to reach their final destination.  And then pro-
grams like gopher and pine protect you from the truly awful
programs native Unix users are familiar with.  But at any
rate, it works.  It's not too hard to learn.  And it's
worth it.  You won't have to spend another day without
the complete electronic text of Shakespeare's works!
































 Electronic Addresses
Every computer on the Internet and every person who uses
the Internet has its/his/her own unique electronic address.
These addresses all follow the same form.  For a user named
Elmer J. Fudd who works at Cal State U. San Marcos the add-
ress might be:
                 [e-mail]

efudd is the user ID Elmer uses to log in.  It's how the com-
puter knows him.  The part of the address following the @
symbol is called the domain.  It is the specific address of
a computer, in this case the computer called coyote at Cal
State within the educational sub-domain.  There are never
any spaces in an Internet address.

 Fully Qualified Domain Names (FQDN)

The address [e-mail] is a fully qualified
domain name.  The domain part of the name (to the right
of the @ symbol) is made up of three sub-domains, and is
read right to left.  The top level domain is edu, a name
given to all educational institutions.  Other top level
domains you will see  are:
        com      commercial organizations
        gov      government
        int      international organization
        mil      military
        net      networking organization
        org      non-profit organization

 FQDNs Etc. Etc.

The next part of Elmer's domain address is csusm.  This
is the name given to all the computers on the internet at
Cal State U. San Marcos.  Finally, the name coyote is the
name of a specific computer at CSUSM.
Typically a FQDN has three parts, but you will see varia-
tions.  Some organizations are large enough to have specific
departments within their subdomain.  For example:
        borg.lib.vt.edu
is the name of a computer within the library at the Univer-
sity of Vermont.  In other cases, some organizations are
so small they only have one computer on the internet, and
their FQDN would be something like: oes.com.

 FQDNs International

When a computer is outside the US, its FQDN must be appended
with an abbreviation indicating the country.  For example:

      at ------ Austria          au ------ Australia
      ca ------ Canada           ch ------ Switzerland
      de ------ Germany          dk ------ Denmark
      fi ------ Finland          fr ------ France
      gr ------ Greece           jp ------ Japan
      uk ------ United Kingdom   za ------ South Africa

music.tuwien.ac.at is the computer called music at Tech. U.
of Vienna.

 The Host Command

Computers are a lot like the alien in the Sigorney Weaver
picture.  They are utterly foreign to us and work by their
own often inscrutible rules.  So it really is with Internet
addresses. They are really numbers in disguise. If you want
to know the real address of a computer on the internet you
issue the host command.  For example:
        host coyote.csusm.edu
will return the message:
        144.37.1.41
This is called coyote's Internet Protocol (IP) address, and
is really all computer's care about.  Name's are just for
human convenience.

 IP Address - So what?
The command:           host borg.lib.vt.edu
returns the message:   128.173.124.25
The command:           host 144.37.1.41
returns the message:   coyote.csusm.edu

See.  It works vice versa.  So what?  Occasionally it
will be impossible to telnet to a location using its named
address, but using its IP address will work.  Furthermore,
only computers really on the Internet have IP addresses.
This is one way to tell if a computer you are corresponding
with is a real Internet site or only a mail gateway to a
real site.  When you log in for real, try the host command
and write down your IP address.