Internet Protocols
The key protocols of the Internet are: News, Gopher, Telnet,
Electronic Mail (e-mail),
File Transfer Protocol (FTP),
and HTTP (World Wide Web).
These and others are integrated in the
Uniform Resource Locator mechanism of the WWW.
Underlying the user interface represented by web browsers,
is the network and the protocols that travel the wires to the servers
or "engines" that process requests, and return the various media.
The protocol of the web is known as HTTP,
for HyperText Transfer Protocol.
HTTP is the underlying mechanism on which CGI operates,
and it directly determines
what you can and cannot send or receive via CGI.
Electronic mail, the sending and receiving of electronic messages,
has long been the most popular use of the Internet.
E-mail is also used on most commercial on-line services,
and for many people, its the main reason for
getting onto the Internet or an on-line service.
To send e-mail, you must know the recipient's e-mail address.
These addresses are composed of
- the user's identification,
- followed by the "@" sign,
- followed by the location (domain name) of the recipient's computer.
The e-mail address for the President of the United States is
president@whitehouse.gov.
The last three letters (.gov) indicate this
location is a government sponsored domain on the Internet.
News
NNTP (Network News Transfer Protocol) is an Internet standard protocol
for distribution, inquiry, retrieval and posting of news articles.
Network News (USENET) is a popular usage of NNTP. It offers bulletin
boards, chat rooms, and netnews,
which is a massive system with over 5,000 ongoing conferences,
called newsgroups, conducted around the clock, 365 days a year.
To access these newsgroups, you download a special program from the
Internet that allows you to participate in any newsgroup you wish.
Most commercial browsers have this capability built in.
You can "subscribe" to those newsgroups that interest you and
communicate through a message system similar to e-mail.
You may simply view an ongoing dialog without participating
(lurking -- advised for newcomers).
To join in the conversation, you "post an article" to the newsgroup.
As with e-mail, Netnews is usually informal communication
between several (sometimes thousands) of individuals!
The "signal-to-noise" ratio (SNR) can be very low..
Some newsgroups are managed by a monitor who may elect not to
post responses that are deemed inappropriate for that forum.
Gopher
Another widely used tool of the Internet is Gopher, a menu-based program
that enables you to browse for information without having to know where
the material is specifically located.
It lets you search lists of resources,
and then helps send the material to you.
When you use Gopher, you navigate the Internet by moving deeper and
deeper into "menus".
The user is presented with a top-level menu, e.g. volume numbers;
the user would move the cursor to one & press Return, which would
then present the second-level menu, e.g. chapter numbers; after
selecting one of these, the next menu is section numbers, etc..
When the user has reached the bottom level, the actual text is
displayed.
This has the advantage of simplicity and familiarity, and it's
fairly easy to set up - the text files would need to be split
down to the desired level of detail, and some description files
would need to be set up. There is a server,
WN, that can serve
both HTTP and gopher requests. It can also be programmed to
interface with WAIS.
The major disadvantage is the inflexibility of the static hierarchy.
The user has to use judgement at each menu selection, as to which
is the most likely item on the menu to contain the information
required.
You can access library catalogs, files, and other databases.
For example, if you are looking for a poem written by your
favorite poet,
you might look first under authors & books, and
then under poetry.
Veronica and Jughead are related programs that assist your search of
Gopherspace (the term for the collective assortment of Internet sites
that run Gopher software). Veronica helps you search gopher systems for
documents; Jughead searches directory titles only.
FTP (File Transfer Protocol) allows you to send files to a remote
computer, or receive them.
You can also update (delete, rename, move, and copy) files at a server.
People who create Web home pages can use FTP to get their files to the
server where they will be accessed.
FTP is included in the suite of protocols that are part of TCP/IP, the
client/server program that every Internet server and your (client) PC
or workstation uses.
You can transfer many different types of files to your computer.
You may want the latest upgrade for a particular software product,
or you might find your favorite movie star's photograph.
There are probably xillions of files available via FTP on the Internet.
The search tool Archie, a client program, helps you find files stored on
FTP sites using keywords that appear in the file names. You enter likely
keywords and Archie searches its database for matches. Archie then sends
you a list with full file names and the address information you need to
retrieve the file via FTP.
Telnet
Telnet provides a way to "log in" to a remote computer;
your keyboard and monitor act as if attached to the remote computer.
You can use the same services as a local user.
You can run programs on a computer on the other side of the world,
just as if you were sitting in front of it.
The remote computer is frequently called a host computer.
Telnet is a user command using the underlying TCP/IP protocol for
accessing remote computers.
You log on as a regular user with whatever privileges you may have
been granted to the specific applications and data on that computer.
Of course, you have to know the operating system and applications
of the remote computer.
You might use Telnet to look at the electronic card catalog from the
Library of Congress or the British Library in London.
You might also use Telnet to browse through government databases.
A number of organizations have written special programs into their
systems so that Internet users can have ready-access to information,
e.g. try
telnet info.cern.ch
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