rfc2324.txt

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RFC 2324                       HTCPCP/1.0                   1 April 1998


   All alternative coffee-scheme forms are equivalent.  However, the use
   of coffee-scheme in various languages MAY be interpreted as an
   indication of the kind of coffee produced by the coffee pot.  Note
   that while URL scheme names are case-independent, capitalization is
   important for German and thus the initial "K" must be encoded.

4. The "message/coffeepot" media type

   The entity body of a POST or BREW request MUST be of Content-Type
   "message/coffeepot". Since most of the information for controlling
   the coffee pot is conveyed by the additional headers, the content of
   "message/coffeepot" contains only a coffee-message-body:

   coffee-message-body = "start" | "stop"

5. Operational constraints

   This section lays out some of the operational issues with deployment
   of HTCPCP ubiquitously.

5.1 Timing Considerations

   A robust quality of service is required between the coffee pot user
   and the coffee pot service.  Coffee pots SHOULD use the Network Time
   Protocol [NTP] to synchronize their clocks to a globally accurate
   time standard.

   Telerobotics has been an expensive technology. However, with the
   advent of the Cambridge Coffee Pot [CAM], the use of the web (rather
   than SNMP) for remote system monitoring and management has been
   proven.  Additional coffee pot maintenance tasks might be
   accomplished by remote robotics.

   Web data is normally static. Therefore to save data transmission and
   time, Web browser programs store each Web page retrieved by a user on
   the user's computer. Thus, if the user wants to return to that page,
   it is now stored locally and does not need to be requested again from
   the server. An image used for robot control or for monitoring a
   changing scene is dynamic. A fresh version needs to be retrieved from
   the server each time it is accessed.

5.2 Crossing firewalls

   In most organizations HTTP traffic crosses firewalls fairly easily.
   Modern coffee pots do not use fire. However, a "firewall" is useful
   for protection of any source from any manner of heat, and not just
   fire. Every home computer network SHOULD be protected by a firewall
   from sources of heat. However, remote control of coffee pots is



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   important from outside the home. Thus, it is important that HTCPCP
   cross firewalls easily.

   By basing HTCPCP on HTTP and using port 80, it will get all of HTTP's
   firewall-crossing virtues. Of course, the home firewalls will require
   reconfiguration or new versions in order to accommodate HTCPCP-
   specific methods, headers and trailers, but such upgrades will be
   easily accommodated. Most home network system administrators drink
   coffee, and are willing to accommodate the needs of tunnelling
   HTCPCP.

6. System management considerations

   Coffee pot monitoring using HTTP protocols has been an early
   application of the web.  In the earliest instance, coffee pot
   monitoring was an early (and appropriate) use of ATM networks [CAM].

   The traditional technique [CAM] was to attach a frame-grabber to a
   video camera, and feed the images to a web server. This was an
   appropriate application of ATM networks. In this coffee pot
   installation, the Trojan Room of Cambridge University laboratories
   was used to give a web interface to monitor a common coffee pot.  of
   us involved in related research and, being poor, impoverished
   academics, we only had one coffee filter machine between us, which
   lived in the corridor just outside the Trojan Room. However, being
   highly dedicated and hard-working academics, we got through a lot of
   coffee, and when a fresh pot was brewed, it often didn't last long.

   This service was created as the first application to use a new RPC
   mechanism designed in the Cambridge Computer Laboratory - MSRPC2. It
   runs over MSNL (Multi-Service Network Layer) - a network layer
   protocol designed for ATM networks.

   Coffee pots on the Internet may be managed using the Coffee Pot MIB
   [CPMIB].

7. Security Considerations

   Anyone who gets in between me and my morning coffee should be
   insecure.

   Unmoderated access to unprotected coffee pots from Internet users
   might lead to several kinds of "denial of coffee service" attacks.
   The improper use of filtration devices might admit trojan grounds.
   Filtration is not a good virus protection method.






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   Putting coffee grounds into Internet plumbing may result in clogged
   plumbing, which would entail the services of an Internet Plumber
   [PLUMB], who would, in turn, require an Internet Plumber's Helper.

   Access authentication will be discussed in a separate memo.

8. Acknowledgements

   Many thanks to the many contributors to this standard, including Roy
   Fielding, Mark Day, Keith Moore, Carl Uno-Manros, Michael Slavitch,
   and Martin Duerst.  The inspiration of the Prancing Pony, the CMU
   Coke Machine, the Cambridge Coffee Pot, the Internet Toaster, and
   other computer controlled remote devices have led to this valuable
   creation.

9. References

   [RFC2068] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., and T.
   Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2068,
   January 1997.

   [RFC2186] Wessels, D., and K. Claffy, "Internet Cache Protocol (ICP),
   version 2," RFC 2186, September 1997

   [CPMIB] Slavitch, M., "Definitions of Managed Objects for Drip-Type
   Heated Beverage Hardware Devices using SMIv2", RFC 2325, 1 April
   1998.

   [HTSVMP] Q. Stafford-Fraser, "Hyper Text Sandwich Van Monitoring
   Protocol, Version 3.2". In preparation.

   [RFC2295] Holtman, K., and A. Mutz, "Transparent Content Negotiation
   in HTTP", RFC 2295, March 1998.

   [SAFE] K. Holtman. "The Safe Response Header Field", September 1997.

   [CAM] "The Trojan Room Coffee Machine", D. Gordon and M. Johnson,
   University of Cambridge Computer Lab,
   <http://www.cl.cam.ac.uk/coffee/coffee.html>

   [CBIO] "The Trojan Room Coffee Pot, a (non-technical) biography", Q.
   Stafford-Fraser, University of Cambridge Computer Lab,
   <http://www.cl.cam.ac.uk/coffee/qsf/coffee.html>.

   [RFC2235] Zakon, R., "Hobbes' Internet Timeline", FYI 32, RFC 2230,
   November 1997.  See also
   <http://www.internode.com.au/images/toaster2.jpg>




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   [NTP] Mills, D., "Network Time Protocol (Version 3) Specification,
   Implementation and Analysis", RFC 1305, March 1992.

   [URLI18N] Masinter, L., "Using UTF8 for non-ASCII Characters in
   Extended URIs" Work in Progress.

   [PLUMB] B. Metcalfe, "Internet Plumber of the Year: Jim Gettys",
   Infoworld, February 2, 1998.

   [COKE] D. Nichols, "Coke machine history", C. Everhart, "Interesting
   uses of networking", <http://www-
   cse.ucsd.edu/users/bsy/coke.history.txt>.

10. Author's Address

   Larry Masinter
   Xerox Palo Alto Research Center
   3333 Coyote Hill Road
   Palo Alto, CA 94304

   EMail: [e-mail]






























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11.  Full Copyright Statement

   Copyright (C) The Internet Society (1998).  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.
























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