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Networking: A Beginner's Guide
TIP
Recent versions of Windows also support FTP connections using Internet Explorer. Just open
Internet Explorer and instead of entering an http:// address in the address bar, type an address
preceded by ftp://. For example, to connect to Microsoft's FTP server, you would use the address
ftp://ftp.microsoft.com. This trick also works in most other current web browsers, such as Mozilla
Firefox. Note that for FTP sites that require a login, the browser must support logging in. In Internet
Explorer, a Logon As option is available on the File menu after you browse to an FTP site.
Network News Transfer Protocol (NNTP)
Usenet (NetNews) is a set of discussion groups devoted to an extremely wide variety of
topics. There are well over 100,000 such such groups in existence. Usenet conversations
are posted to Usenet servers, which then echo their messages to all other Usenet servers
around the world. A posted message can travel to all the Usenet servers in a matter of
hours, and then be available to users accessing any particular Usenet server.
Usenet discussion groups are loosely organized into the branches of a tree. The
following are some of the main branches:
Alt, for discussions about alternative lifestyles and other miscellaneous topics
Comp, for computer-oriented discussions
Gov, for government-oriented discussions
Rec, devoted to recreational topics
Sci, for science-based discussions
Usenet groups can either be public, which are echoed to other Usenet servers, or
private, which are usually hosted by a particular organization and require the user to
enter appropriate login credentials before reading and posting messages.
The NNTP protocol is what makes Usenet possible. It allows for a connection between
a Usenet reader (also called a news reader) and a Usenet server. It also provides for message
formatting, so messages can be text-based or can also contain binary attachments. Binary
attachments in Usenet postings are usually encoded using Multipurpose Internet Message
Encoding (MIME), which is also used for most e-mail attachments. Some older systems
use different methods to encode attachments, including one method called UUEncode/
UUDecode and, on the Macintosh, a method called BinHex.
Telnet
Telnet defines a protocol that allows a remote terminal session to be established with an
Internet host, so remote users have access similar to using a terminal connected directly
to the host computer. Using Telnet, users can control the remote host, performing tasks
such as managing files, running applications, or even (with appropriate permissions)
administering the remote system. Telnet is a session-layer protocol in the OSI model.
For Telnet to work, Telnet software must be running on both the server and client
computer. You run the program Telnet on a client computer and run the program Telnetd
on the server computer to allow the connection. Telnet is specific to the TCP protocol