rfc2664.txt

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2.5. How Does the Internet Work?

   Each of the activities mentioned in the section describing what one
   can do on the Internet requires that computers exchange information.
   Computers take turns sending and receiving information.  When a
   computer is sending information, it is known as the "source"; when it
   is receiving information, it is known as the "destination."  (The
   same computer can be both a source and destination at different
   times.  This is especially clear when one thinks of sending and
   receiving e-mail.)

   Every computer on the Internet has a unique Internet "address" that
   identifies it from among the millions of computers.  The Internet has
   specialized computers between the source and destination located at
   network inter-connection points.  These computers are known as
   "routers."  The routers understand how to use a computer's address to
   appropriately point information from one computer to another over the
   Internet.

   In an exchange of information the following occurs:

     *  The source finds the address of the destination.

     *  The source contacts the destination and says "hello".



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     *  The destination responds back with a "hello" of its own.

     *  The source tells the destination that it has information to
        send.

     *  The destination tells the source that it is ready to receive the
        information.

     *  The source breaks the information into small pieces called
        packets and sends each packet on its way to the destination.

     *  The routers guide each packet to the destination.

     *  The destination takes the packets and puts them back together to
        form the information.

     *  The destination tells the source that it has received the
        information and asks the source if it has anything more to send.

     *  If the source says no, the destination will say "good bye"
        unless it has something to send back.  If it does, it will break
        the information into packets and send them.

     *  Once both end users are done "talking", they say both say "good
        bye".

   Clearly our simplified introduction to this section did not explain
   many steps in this process, such as how a computer discovers the
   address of another computer or how packets are divided and
   reassembled.  Fortunately, these are specifics that people using the
   Internet never really need to deal with!

2.6  Who Runs the Internet?

   No one.  The Internet is a cooperative effort among Internet Service
   Providers (ISPs), software companies, volunteer organizations, and a
   few facilities that tie the whole thing together.  The ISPs and
   software companies are completely independent and most of them
   compete with each other.  The ISPs provide internet service to people
   much the same way that they obtain telephone service from a telephone
   company.  ISPs agree to connect their networks to each other and
   transmit information following an established set of rules
   (protocols).  The software companies agree to manufacture programs
   (such as email or web browsers) that also follow protocols.  There
   are other organizations that keep things straight.  Some assign
   Internet addresses in much the same manner as telephone numbers are
   assigned, others keep track of names used by Internet users and
   groups, and a large volunteer organization called the Internet



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   Engineering Task Force (IETF) develops the protocols computers follow
   to make network communications succeed.

3. Security Considerations

   The question "is the Internet secure?" can be a confusing one for
   people, who will hear many assurances that it is secure and many
   scary stories saying it is not secure.  There are a few basic rules
   of thumb to remember that will address most concerns.

   First, make it a rule never to share account passwords with anyone.
   Learning a password is the easiest way for someone to break into a
   system.  Most people feel that their files are not that interesting
   to anyone, but someone may be able to get a foothold from one
   innocuous account to other places in the same computer system.  Many
   good security practices can be found in the User's Security Handbook
   [FYI 34, RFC 2504].

   Second, understand that there are means for people to track the
   information a user sends via email, the files one downloads, and the
   sites visited on the web.  The system administrators and network
   engineers who oversee a sites' computers require access to
   information that an individual may think is secret.  In practice, no
   responsible system administrator or network engineer will violate a
   person's privacy out of personal curiosity.  However, if someone less
   legitimate attains illegal access to a system, they also will have
   access to this information.  This situation is not a problem for most
   people, but it should be understood that things like email sent a
   year ago or a log of users web pages browsed may still exist in some
   system's backup archive tape and can be easily resurrected and
   published widely.

   Third, before giving personal information over the Internet, such as
   filling in a form on a Web page, users should realize that there is
   no assurance of confidentiality or privacy.   It could be compared to
   faxing such information to a party that you've never dealt with
   before.  While many organizations on the Internet are responsible
   with information received via the web and email, this cannot always
   be determined in advance.

4.  References

   [1] Guttman, E., Leong, G. and G. Malkin, "Users' Security Handbook",
       FYI 34, RFC 2504, February 1999.

   [2] Hambridge, S., "Netiquette Guidelines", FYI 28, RFC 1855, October
       1995.




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5.  Authors' Addresses

   Raymond Plzak
   SAIC
   1710 Goodridge Drive
   McLean, Virginia 22102

   Phone: [phone]
   EMail: [e-mail]


   Amy Tracy Wells
   Internet Scout Project
   University of Wisconsin-Madison
   Computer Sciences Department
   1210 W. Dayton St.
   Madison, WI 53706

   Phone: [phone]
   EMail:  [e-mail]


   Ed Krol
   University of Illinois
   1120 DCL
   1304 Springfield
   Urbana IL   61801

   Phone [phone]
   EMail: [e-mail]





















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Appendix A

   Glossary of Terms

   Emoticon      Combination of punctuation marks used to provide sense
                 of the senders tone of voice in an e-mail message

   IETF          Internet Engineering Task Force [see text for a
                 description]

   Internet      An interconnected group of networks

   ISP           Internet Service Provider [see text for a description]

   Network       A connected group of computers

   Router        A specialized computer that connects networks together
                 and guides information packets to their destination

   Spam          A slang term for junk e-mail

   URL           Uniform Resource Locator [see text for a description]

   Web Browser   A program that provides the capablility to read
                 information that is located at a world wide web site


























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6.  Full Copyright Statement

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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