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Table of Contents
Introduction
The Internet
Imposing isn't it? This is a pictorial representation of the links between
computers that make up a part of the Internet. The points on the map are
clusters of computers such as those at BGSU. The points above the map are
large computers whose task it is to act as hubs to pass the communication
packets around the internet. The lines between these points are the pathways
that connect computers together. The heaviest of these lines, the ones
that pass between the large points above the map, are what is know as a
backbone. This backbone is the main conduit for the communications packets
that make the Internet what it is in North America. This is not by any
means the whole Internet, it is only a graphical representation of North
America's piece of the Internet.
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Network Protocols
When you connect to the Internet and utilize an application such as a world
wide web browser you are communicating over what is called a packet switching
network. The internet takes the data that you are sending and chops it
up into bite sized chunks that are addressed with the senders and recipients
internet addresses. These packets then make their way out across the internet
and hopefully reach their destination. Replies to these packets retrace
the course of the ones first sent and return to your computer. This process
is all seamlessly implemented by the internet and your internet client
program.
This Packet switching network called the Internet is governed by a host
of rules that tell the hardware and software of the Internet how to handle
each and every packet it encounters. These rules or protocols tell each
software and hardware system how to interact with the other parts of the
internet near it.
One example of a protocol that you may be familiar with is the PPP, or
Point to Point Protocol. This is the method that the majority of WCIC clients
use to connect to the internet. This protocol allows a high speed modem
to call in over standard phone lines and make a network connection to the
wcic terminal server xyplex. This network protocol allows you to see the
world wide web in all its glory, graphics and all.
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Domains
Internet domains are an addressing scheme meant to make the Internet address
a little more user friendly than it actually is. Lets take the case of
our familiar wcnet.org address. The address takes the form of a
series of letters separated into parts by periods. In our case the two
parts of the domain name are wcnet and org. The domain name
is split up in this manner to allow anyone on the internet to find a new
Internet address. The org part of the address stands for organization
and is a domain that is reserved for not-for-profit organizations. Another
top level domain is com this domain stands for commercial and is
the realm of the business internet site. Each domain maintains a list of
the domains one level directly under it. So the org domain maintains
a list of all sites that have two parts and end in org. Each domain
in that list maintains a list of the domains one level under them and so
on. With this addressing scheme it is possible for local systems to make
changes in the structure of the internet and to have those changes implemented
immediately over the entire internet addressing scheme.
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E-mail
E-mail is often one of the first ways that we interact with the internet
at large. It is a method of sending "private" messages over the
internet network, much in the same manner that you might post a letter
to a friend using the US postal service. There are two major differences,
however, between the US postal service and Internet E-mail: Internet e-mail
is free and you don't have to cut down trees to use it. All you need to
send e-mail is access to an e-mail account and the address of the recipient.
If you have an account with the WCIC freenet then you have an e-mail account.
Your address is in the form of jpublic@wcnet.org. This address is separated
into two parts by the "@" symbol. The part to the left of the
"@" is the name of the email account on the machine that is addressed
by the part of the address to the right of the "@" symbol. In
the case above we have an e-mail account named jpublic at a domain called
wcnet.org.
E-mail can provide a number of varied services, many of which are unknown
to the majority of users. It can, of course, be used to send a single private
message to a friend cross town or across the globe. There are email interfaces
to WAIS databases and to ARCHIE. There are mailing lists that copy the
messages that you send to the list and distribute them to everyone else
who is also on the list, sort of a mass mailing for the internet. These
mailing lists generally have topics and people who are on the list are
always there by choice. It is is extremely rude to include someone on a
mailing list against their wishes or to make an unsolicited mass mailing.
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World Wide Web
The popularity of the world wide web or WWW or web, as I will refer to
it in the future, is probably responsible for the phenomenal growth in
the Internet today. The web is a system, or structure, that allows users
to navigate a vast array of electronic documents at the click of a mouse.
These documents are published on machines all over the globe using a kind
of programming language called HTML or Hyper Text Markup Language. This
language is descended from the markup languages originally used for the
first computerized type-setting systems in the printing industry. The web
can be seen as a series of pages that are linked together at a great many
points. A user may choose one link and be connected to the home page of
one of our clients at wcic freenet such as the one found at http://www.wcnet.org/~cobee/
or to a search engine such as Yahoo.
These pages are linked to this document and you may access them just by
clicking on the link. This process of moving over the links of the web
is sometimes called "surfing the web." It usually means a sort
of wandering progression where you simply follow your nose and look for
things of interest. There is a vast array of information out on the web
and it grows and changes everyday.
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Usenet Newsgroups
The Usenet Newsgroups are a messaging system that incorporates a myriad
of topics: 4000 different ones and growing every day. These newsgroups
are a way for a large number of people to interact in the same set of conversations
all with common threads. Here at the WCIC freenet we have a few special
newsgroups just for our use. All of these are under the top level name
of wcnet and take the form of wcnet.general, wcnet.announce, ect. All of
the usenet newsgroups take this general form. The main top level groups
in the newsgroups are: rec for recreational, alt for alternative, misc
for miscellaneous, comp for computer, bit for bitnet. These top level groups
are further divided into sub groups and so on until you come to an actual
message area. In the case of the Usenet newsgroup dedicated to the New
Orleans Saints football team the news group is called alt.sports.pro.football.no-saints.
This shows how complicated the names can get.
This form of messaging can be a wild and woolly place. The Usenet newsgroups
are a, largely, uncontrolled media where a lot of material of questionable
content can be found. Parents may want to monitor the usenet newsgroups
that young children access. Fortunately the names of the usenet newsgroups
are pretty specific. There is little question that a newsgroup named alt.sex.erotica
may be unfit for young children.
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File Transfer Protocol
FTP is the copy command of the internet. It's a little more complicated
than that because of the slightly more complicated nature of the internet.
There are two sorts of FTP. First the is the sort of FTP that allows you
to upload your web page to your public_html directory. This sort of connection
is one that you can make through the wcnet machine to your own account
space. It requires that you know your username and your password. The other
type is called anonymous ftp. With anonymous ftp you can logon to a computer
that allows this sort of connection by typing in a username of anonymous
and the password being your username e.g.. jpublic@wcnet.org. This
sort of connection allows you to peruse the collection of files found on
anonymous ftp servers around the world. If you want a place to start, you
might try the software collection at oak.oakland.edu, a truly enormous
ftp site. Be aware that if you access these sites using the ftp available
over the wcic terminal connection, you will be required to master a few
ftp commands. The essentials are:
-
cd (directory name)
-
"change directory" where (directory name) is name of the
directory that you wish to change to. Remember that the vast majority of
anonymous servers are unix systems and the two directories "mydir"
and "Mydir" are two completely different directories. In other
words, case matters. The majority of files available for download are found
in the "pub" directory.
-
cd ..
-
"change to the parent directory" just like the regular cd
command except that the two periods mean the directory directly above the
current directory.
-
dir
-
"directory" this command lists the contents of the current
directory.
-
get (filename)
-
"download a file" where (filename) is the name of the file
you want to download.
-
send (filename)
-
"upload a file" where (filename) is the name of the file
you wish to upload.
-
bye
-
"end you FTP session" This function is used when you wish
to terminate the FTP connection.
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Telnet
Telnet is the terminal emulation of the internet. It allows PPP users to
login to the wcnet machine directly and it allows all users to login to
computer systems across the globe. To logon to another computer system
you will most likely need an account on that machine. In some cases the
username guest, with the password guest, is a valid combination. Other
systems may in some way publish a guest account and password. The use of
a telnet client is mostly used to logon to the WCIC freenet machine to
change your password.
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Internet Relay Chat
The IRC networks that dominate the chat scene are Dalnet, Effnet, and Undernet.
These are all large chat networks where live interactive chat can be found
at any hour of the day or night. In fact, the night is probably the busiest
time. Like the Usnet Newsgroups, IRC is an area of very little control
and in the opinion of myself, chris
obee, it is the place on the internet most likely to pose serious threats
to the safety of children. The interactive nature of IRC allows unscrupulous
characters to solicit private information from a user while easily posing
as a non-threatening character. This, perhaps, overstates the threat of
IRC; it is mostly a place of silly inconsequential chat. There have been
serious uses applied to IRC. During some natural disasters, and other world
wide events, IRC can be a source of the very latest breaking news.
IF you have a desire to use the IRC networks, do yourself a favor and look
for the mIRC shareware IRC client.
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Gopher
Gopher was the original point and click interface of the internet. It has
now been largely replaced by the world wide web. Gopher servers still survive
around the world but the majority of new information being put on the Internet
is being served by http web servers. Gopher is a text based rodent oriented
interface meant to permit easy access to a large number of text documents.
It still serves this purpose to some extent as most web browsers are perfectly
happy accessing gopher servers. This backwards capability means that the
information on the gopher network need not be moved to a web environment
to be accessible. Thus, there is no need to migrate the text documents
currently being maintained by gopher servers to web servers.
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Veronica
Veronica is a gopher space search engine. The Veronica search engine can
search all known gopher servers for key words, names of directories or
the like. Veronica, since it is part of the nearly defunct gopher network
is now nearly defunct itself.
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Archie
Archie is the precursor of the web based software search engine. Archie's
purpose is to keep track of the location of all the files on the Internet
that are available by anonymous FTP. The archie server cataloged files
by name and description and made it possible for a user to search by keyword
or filename. Archie then returned a list with associated locations for
matches to the search criteria. One of the nice features of archie is the
e-mail interface. It allows users to mail in their archie search queries
and receive results by return e-mail.
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WAIS
WAIS stands for Wide Area Information Server. This is a distributed system
database. That is to say that the information available to be searched
is contained in many different systems. The advantage of a WAIS database
over a gopher site or an achie index is that the documents themselves can
be searched for their content as well as for their title or description.
The archie system and veronica gopher search engine could never look inside
a document for a keyword. This works much the same way that the web based
search engines work. Multiple hits are recorded when a document has many
repetitions of the same search term within it. WAIS, like veronica and
archie, has been hit hard by the proliferation of the World wide web.
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Universal Resource Locator
The URL or Universal Resource Locator is the a combination of three things.
First let us consider a simple URL:
http://www.wcnet.org/~cobee/saints.html
Lets look at the URL one part at a time. The first part of the URL indicates
the protocol to be used. In this case it's http, which is the protocol
of the world wide web. Some other possible protocols are telnet, news or
gopher. The second part of the URL is the domain name of the server where
the document is located. In this case, www.wcnet.org indicates our WCIC
freenet world wide web server. The next part is a file name. Here the file
is ~cobee/saints.html, telling the computer it's in the account of cobee,
with a name of saints.html and is an html document. The Universal resource
locator is a very complete way of specifying all the information that is
needed to manage the complexities of accessing a file on the Internet today.
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