path: root/doc/rfc/rfc3288.txt

Network Working Group                                      E. O'Tuathail
Request for Comments: 3288                                  Clipcode.com
Category: Standards Track                                        M. Rose
                                            Dover Beach Consulting, Inc.
                                                               June 2002


            Using the Simple Object Access Protocol (SOAP)
             in Blocks Extensible Exchange Protocol (BEEP)

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This memo specifies a Simple Object Access Protocol (SOAP) binding to
   the Blocks Extensible Exchange Protocol core (BEEP).  A SOAP binding
   describes how SOAP messages are transmitted in the network.

   The SOAP is an XML-based (extensible markup language) messaging
   protocol used to implement a wide variety of distributed messaging
   models.  It defines a message format and describes a variety of
   message patterns, including, but not limited to, RPC, asynchronous
   event notification, unacknowledged messages, and forwarding via SOAP
   intermediaries.

















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Table of Contents

   1.    Introduction . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.    BEEP Profile Identification  . . . . . . . . . . . . . . . .  4
   2.1   Profile Initialization . . . . . . . . . . . . . . . . . . .  5
   3.    SOAP Message Packages  . . . . . . . . . . . . . . . . . . .  7
   4.    SOAP Message Patterns  . . . . . . . . . . . . . . . . . . .  9
   4.1   One-way Message  . . . . . . . . . . . . . . . . . . . . . .  9
   4.2   Request-Response Exchange  . . . . . . . . . . . . . . . . .  9
   4.3   Request/N-Responses Exchange . . . . . . . . . . . . . . . .  9
   5.    URL Schemes  . . . . . . . . . . . . . . . . . . . . . . . . 10
   5.1   The soap.beep URL Scheme . . . . . . . . . . . . . . . . . . 10
   5.1.1 Resolving IP/TCP Address Information . . . . . . . . . . . . 10
   5.2   The soap.beeps URL Scheme  . . . . . . . . . . . . . . . . . 11
   6.    Registration Templates . . . . . . . . . . . . . . . . . . . 12
   6.1   SOAP Profile Feature Registration Template . . . . . . . . . 12
   7.    Initial Registrations  . . . . . . . . . . . . . . . . . . . 13
   7.1   Registration: The SOAP Profile . . . . . . . . . . . . . . . 13
   7.2   Registration: The soap.beep URL Scheme . . . . . . . . . . . 14
   7.3   Registration: The soap.beeps URL Scheme  . . . . . . . . . . 15
   7.4   Registration: The System (Well-Known) TCP port number for
         SOAP over BEEP . . . . . . . . . . . . . . . . . . . . . . . 15
   8.    Security Considerations  . . . . . . . . . . . . . . . . . . 16
         References . . . . . . . . . . . . . . . . . . . . . . . . . 17
         IANA Considerations  . . . . . . . . . . . . . . . . . . . . 18
         Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18
         Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 19
         Full Copyright Statement . . . . . . . . . . . . . . . . . . 20























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1. Introduction

   This memo specifies how SOAP 1.1 envelopes[1] are transmitted using a
   BEEP profile[2].  In the W3C, the XMLP effort is evolving SOAP.
   Accordingly, this memo provides a mechanism for negotiating the use
   of new features.

   Throughout this memo, the term "envelope" refers to the "SOAP-
   Env:Envelope" element defined in Section 4 of [1].  Further, the
   terms "peer", "client", "server", "one-to-one", and "one-to-many" are
   used in the context of BEEP.  In particular, Sections 2.1 and 2.1.1
   of [2] discuss BEEP roles and exchange styles.







































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2. BEEP Profile Identification

   The BEEP profile for SOAP is identified as

       http://iana.org/beep/soap

   in the BEEP "profile" element during channel creation.

   In BEEP, when the first channel is successfully created, the
   "serverName" attribute in the "start" element identifies the "virtual
   host" associated with the peer acting in the server role, e.g.,

       <start number='1' serverName='stockquoteserver.example.com'>
           <profile uri='http://iana.org/beep/soap' />
       </start>

   The "serverName" attribute is analagous to HTTP's "Host" request-
   header field (c.f., Section 14.23 of [3]).

   There are two states in the BEEP profile for SOAP, "boot" and
   "ready":

   o  In the "boot" state, the peer requesting the creation of the
      channel sends a "bootmsg" (either during channel initialization or
      in a "MSG" message).

      *  If the other peer sends a "bootrpy" (either during channel
         initialization or in a "RPY" message), then the "ready" state
         is entered

      *  Otherwise, the other peer sends an "error" (either during
         channel initialization or in a "ERR" message), then no state
         change occurs.

   o  In the "ready" state, either peer begins a SOAP message pattern by
      sending a "MSG" message containing an envelope.  The other peer
      completes the message pattern either by:

      *  sending back a "RPY" message containing an envelope; or,

      *  sending back zero or more "ANS" messages, each containing an
         envelope, followed by a "NUL" message.

      Regardless, no state change occurs.







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2.1 Profile Initialization

   The boot message is used for two purposes:

      resource identification: each channel bound to the BEEP profile
      for SOAP provides access to a single resource (a network data
      object or service).

      feature negotiation: if new features of SOAP (such as compression)
      emerge, their use can be negotiated.

   The DTD syntax for the boot message and its response are:

       <!ELEMENT bootmsg     EMPTY>
       <!ATTLIST bootmsg
                 resource    CDATA             #REQUIRED
                 features    NMTOKENS          "">

       <!ELEMENT bootrpy     EMPTY>
       <!ATTLIST bootrpy
                 features    NMTOKENS          "">

   The boot message contains a mandatory and an optional attribute:

   o  the "resource" attribute, which is analagous to HTTP's "abs_path"
      Request-URI parameter (c.f., Section 5.1.2 of [3]); and,

   o  the "features" attribute, which, if present, contains one or more
      feature tokens, each indicating an optional feature of the BEEP
      profile for SOAP that is being requested for possible use over the
      channel.

   Section 6.1 defines a registration template for optional features.

   If the peer acting in the server role recognizes the requested
   resource, it replies with the boot response that contains one
   optional attribute:

   o  the "features" attribute, if present, contains a subset of the
      feature tokens in the boot message, indicating which features may
      be used over the channel.  (If not present or empty, then no
      features may be used.)

   Otherwise, if the boot message is improperly formed, or if the
   requested resource isn't recognized, the peer acting in the server
   role replies with an error message (c.f., Section 7.1 of [2]).





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   Typically, the boot message and its response are exchanged during
   channel initialization (c.f., Section 2.3.1.2 of [2]).

   For example, here the boot message and its response are exchanged
   during channel initialization:

       C: <start number='1' serverName='stockquoteserver.example.com'>
       C:     <profile uri='http://iana.org/beep/soap'>
       C:         <![CDATA[<bootmsg resource='/StockQuote' />]]>
       C:     </profile>
       C: </start>

       S: <profile uri='http://iana.org/beep/soap'>
       S:     <![CDATA[<bootrpy />]]>
       S: </profile>

   The channel bound to the BEEP profile for SOAP is now in the "ready"
   state.

   Alternatively, here is an example in which the boot exchange is
   unsuccessful:

       C: <start number='1' serverName='stockquoteserver.example.com'>
       C:     <profile uri='http://iana.org/beep/soap'>
       C:         <![CDATA[<bootmsg resource='/StockPick' />]]>
       C:     </profile>
       C: </start>

       S: <profile uri='http://iana.org/beep/soap'>
       S:     <![CDATA[<error code='550'>resource not
       S:                                supported</error>]]>
       S: </profile>

   Although the channel was created successfully, it remains in the
   "boot" state.
















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3. SOAP Message Packages

   The BEEP profile for SOAP transmits envelopes encoded as UTF-8 using
   the media type "application/xml"[4], e.g.,

   MSG 1 1 . 0 364
   Content-Type: application/xml

   <SOAP-ENV:Envelope
     xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
     SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
       <SOAP-ENV:Body>
          <m:GetLastTradePrice xmlns:m="Some-URI">
              <symbol>DIS</symbol>
          </m:GetLastTradePrice>
       </SOAP-ENV:Body>
   </SOAP-ENV:Envelope>
   END

































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   In addition, the BEEP profile for SOAP also allows envelopes to be
   transmitted as the root part of a "multipart/related"[5] content, and
   with subordinate parts referenced using the rules of Section 3 of [6]
   (i.e., using either the "Content-ID:"[7] or "Content-Location:"[8]
   headers), e.g.,

   MSG 1 2 . 364 668
   Content-Type: multipart/related; boundary="MIME_boundary";
                 type=application/xml;
                 start="<claim061400a.xml@claiming-it.com>"

   --MIME_boundary
   Content-Type: application/xml
   Content-ID: <claim061400a.xml@claiming-it.com>

   <?xml version='1.0' ?>
   <SOAP-ENV:Envelope
     xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
   <SOAP-ENV:Body>
   ..
   <theSignedForm href="cid:claim061400a.tiff@claiming-it.com" />
   ..
   </SOAP-ENV:Body>
   </SOAP-ENV:Envelope>

   --MIME_boundary
   Content-Type: image/tiff
   Content-Transfer-Encoding: binary
   Content-ID: <claim061400a.tiff@claiming-it.com>

   ...binary TIFF image...
   --MIME_boundary--
   END

   Consistent with Section 2 of [6], it is strongly recommended that the
   multipart contain a "start" parameter, and that the root part contain
   a "Content-ID:" header.  However, because BEEP provides an 8bit-wide
   path, a "transformative" Content-Transfer-Encoding (e.g., "base64" or
   "quoted-printable") should not be used.  Further note that MIME[9]
   requires that the value of the "Content-ID" header be globally
   unique.










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4. SOAP Message Patterns

4.1 One-way Message

   A one-way message involves sending a message without any response
   being returned.

   The BEEP profile for SOAP achieves this using a one-to-many exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server immediately sends back a "NUL" message, before processing
   the contents of the envelope.

4.2 Request-Response Exchange

   A request/response exchange involves sending a request, which results
   in a response being returned.

   The BEEP profile for SOAP achieves this using a one-to-one exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server sends back a "RPY" message containing an envelope.

   Finally, the BEEP profile for SOAP does not use the "ERR" message for
   SOAP faults when performing one-to-one exchanges -- whatever response
   is generated by the server is always returned in the "RPY" message.

4.3 Request/N-Responses Exchange

   A request/N-responses exchange involves sending a request, which
   results in zero or more responses being returned.

   The BEEP profile for SOAP achieves this using a one-to-many exchange,
   in which the client sends a "MSG" message containing an envelope, and
   the server sends back zero or more "ANS" messages, each containing an
   envelope, followed by a "NUL" message.

















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5. URL Schemes

   This memo defines two URL schemes, "soap.beep" and "soap.beeps",
   which identify the use of SOAP over BEEP over TCP.  Note that, at
   present, a "generic" URL scheme for SOAP is not defined.

5.1 The soap.beep URL Scheme

   The "soap.beep" URL scheme uses the "generic URI" syntax defined in
   Section 3 of [10], specifically:

   o  the value "soap.beep" is used for the scheme component; and,

   o  the server-based naming authority defined in Section 3.2.2 of [10]
      is used for the authority component.

   o  the path component maps to the "resource" component of the boot
      message sent during profile initialization (if absent, it defaults
      to "/").

   The values of both the scheme and authority components are case-
   insensitive.

   For example, the URL

       soap.beep://stockquoteserver.example.com/StockQuote

   might result in the example shown in Section 2.1.

5.1.1 Resolving IP/TCP Address Information

   The "soap.beep" URL scheme indicates the use of the BEEP profile for
   SOAP running over TCP/IP.

   If the authority component contains a domain name and a port number,
   e.g.,

       soap.beep://stockquoteserver.example.com:1026

   then the DNS is queried for the A RRs corresponding to the domain
   name, and the port number is used directly.










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   If the authority component contains a domain name and no port number,
   e.g.,

       soap.beep://stockquoteserver.example.com

   the SRV algorithm[11] is used with a service parameter of "soap-beep"
   and a protocol parameter of "tcp" to determine the IP/TCP addressing
   information.  If no appropriate SRV RRs are found (e.g., for "_soap-
   beep._tcp.stockquoteserver.example.com"), then the DNS is queried for
   the A RRs corresponding to the domain name and the port number used
   is assigned by the IANA for the registration in Section 7.4.

   If the authority component contains an IP address, e.g.,

       soap.beep://10.0.0.2:1026

   then the DNS is not queried, and the IP address is used directly.  If
   a port number is present, it is used directly; otherwise, the port
   number used is assigned by the IANA for the registration in Section
   7.4.

   While the use of literal IPv6 addresses in URLs is discouraged, if a
   literal IPv6 address is used in a "soap.beep" URL, it must conform to
   the syntax specified in [12].

5.2 The soap.beeps URL Scheme

   The "soap.beeps" URL scheme is identical, in all ways, to the
   "soap.beep" URL scheme specified in Section 5.1, with the exception
   that prior to starting the BEEP profile for SOAP, the BEEP session
   must be tuned for privacy.  In particular, note that both URL schemes
   use the identical algorithms and parameters for address resolution as
   specified in Section 5.1.1 (e.g., the same service name for SRV
   lookups, the same port number for TCP, and so on).

   There are two ways to perform privacy tuning on a BEEP session,
   either:

   o  a transport security profile may be successfully started; or,

   o  a user authentication profile that supports transport security may
      be successfully started.

   Regardless, upon completion of the negotiation process, a tuning
   reset occurs in which both BEEP peers issue a new greeting.  Consult
   Section 3 of [2] for an example of how a BEEP peer may choose to
   issue different greetings based on whether privacy is in use.




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6. Registration Templates

6.1 SOAP Profile Feature Registration Template

   When a feature for the BEEP profile for SOAP is registered, the
   following information is supplied:

   Feature Identification: specify a string that identifies this
      feature.  Unless the feature is registered with the IANA, the
      feature's identification must start with "x-".

   Feature Semantics: specify the semantics of the feature.

   Contact Information: specify the electronic contact information for
      the author of the feature.




































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7. Initial Registrations

7.1 Registration: The SOAP Profile

   Profile Identification: http://iana.org/beep/soap

   Messages exchanged during Channel Creation: bootmsg, bootrpy

   Messages starting one-to-one exchanges: bootmsg, SOAP-Env:Envelope

   Messages in positive replies: bootrpy, SOAP-Env:Envelope

   Messages in negative replies: error

   Messages in one-to-many exchanges: SOAP-Env:Envelope

   Message Syntax: SOAP-Env:Envelope as defined in Section 4 of [1] and
      [6]

   Message Semantics: c.f., [1]

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>




























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7.2 Registration: The soap.beep URL Scheme

   URL scheme name: soap.beep

   URL scheme syntax: c.f., Section 5.1

   Character encoding considerations: c.f., the "generic URI" syntax
      defined in Section 3 of [10]

   Intended usage: identifies a SOAP resource made available using the
      BEEP profile for SOAP

   Applications using this scheme: c.f., "Intended usage", above

   Interoperability considerations: n/a

   Security Considerations: c.f., Section 8

   Relevant Publications: c.f., [1], [6], and [2]

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

   Author/Change controller: the IESG



























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7.3 Registration: The soap.beeps URL Scheme

   URL scheme name: soap.beeps

   URL scheme syntax: c.f., Section 5.2

   Character encoding considerations: c.f., the "generic URI" syntax
      defined in Section 3 of [10]

   Intended usage: identifies a SOAP resource made available using the
      BEEP profile for SOAP after the BEEP session has been tuned for
      privacy

   Applications using this scheme: c.f., "Intended usage", above

   Interoperability considerations: n/a

   Security Considerations: c.f., Section 8

   Relevant Publications: c.f., [1], [6], and [2]

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>

   Author/Change controller: the IESG


7.4 Registration: The System (Well-Known) TCP port number for SOAP over
    BEEP

   Protocol Number: TCP

   Message Formats, Types, Opcodes, and Sequences: c.f., Section 2.1

   Functions: c.f., [1]

   Use of Broadcast/Multicast: none

   Proposed Name: SOAP over BEEP

   Short name: soap-beep

   Contact Information: Eamon O'Tuathail <eamon.otuathail@clipcode.com>,
      Marshall Rose <mrose@dbc.mtview.ca.us>







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8. Security Considerations

   Although service provisioning is a policy matter, at a minimum, all
   implementations must provide the following tuning profiles:

   for authentication: http://iana.org/beep/SASL/DIGEST-MD5

   for confidentiality: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_3DES_EDE_CBC_SHA cipher)

   for both: http://iana.org/beep/TLS (using the
      TLS_RSA_WITH_3DES_EDE_CBC_SHA cipher supporting client-side
      certificates)

   Further, implementations may choose to offer MIME-based security
   services providing message integrity and confidentiality, such as
   OpenPGP[13] or S/MIME[14].

   Regardless, consult [2]'s Section 9 for a discussion of BEEP-specific
   security issues.































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References

   [1]   Box, D., Ehnebuske, D., Kakivaya, G., Layman, A., Mendelsohn,
         N., Nielsen, H., Thatte, S. and D. Winer, "Simple Object Access
         Protocol (SOAP) 1.1", May 2000, <http://www.w3.org/TR/2000/
         NOTE-SOAP-20000508>.

   [2]   Rose, M., "The Blocks Extensible Exchange Protocol Core", RFC
         3080, March 2001.

   [3]   Fielding, R., Gettys, J., Mogul, J., Nielsen, H., Masinter, L.,
         Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol --
         HTTP/1.1", RFC 2616, June 1999.

   [4]   Murata, M., St.Laurent, S. and D. Kohn, "XML Media Types", RFC
         3023, January 2001.

   [5]   Levinson, E., "The MIME Multipart/Related Content-type", RFC
         2387, August 1998.

   [6]   Barton, J., Thatte, S. and H. Nielsen, "SOAP Messages with
         Attachments", December 2000, <http://www.w3.org/TR/2000/NOTE-
         SOAP-attachments-20001211>.

   [7]   Levinson, E., "Content-ID and Message-ID Uniform Resource
         Locators", RFC 2392, August 1998.

   [8]   Palme, F., Hopmann, A., Shelness, N. and E. Stefferud, "MIME
         Encapsulation of Aggregate Documents, such as HTML (MHTML)",
         RFC 2557, March 1999.

   [9]   Freed, N. and N. Borenstein, "Multipurpose Internet Mail
         Extensions (MIME) Part One: Format of Internet Message Bodies",
         RFC 2045, November 1996.

   [10]  Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform
         Resource Identifiers (URI): Generic Syntax", RFC 2396, August
         1998.

   [11]  Gulbrandsen, A., Vixie, P. and L. Esibov, "A DNS RR for
         specifying the location of services (DNS SRV)", RFC 2782,
         February 2000.

   [12]  Haskin, D. and E. Allen, "IP Version 6 over PPP", RFC 2472,
         December 1998.

   [13]  Elkins, M., Del Torto, D., Levien, R. and T. Roessler, "MIME
         Security with OpenPGP", RFC 3156, August 2001.



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   [14]  Ramsdell, B., "S/MIME Version 3 Message Specification", RFC
         2633, June 1999.

IANA Considerations

   The IANA has registered the profile specified in Section 7.1 as:

         http://iana.org/beep/soap

   The IANA has registered "soap.beep" and "soap.beeps" as URL schemes,
   as specified in Section 7.2 and Section 7.3, respectively.

   The IANA has also registered "SOAP over BEEP" as a TCP port number,
   as specified in Section 7.4.

   Finally, the IANA maintains a list of SOAP profile features, c.f.,
   Section 6.1.  The IESG is responsible for assigning a designated
   expert to review the specification prior to the IANA making the
   assignment.  Prior to contacting the IESG, developers of SOAP profile
   features must use the mailing list beepwg@lists.beepcore.org to
   solicit commentary.

Acknowledgements

   The authors gratefully acknowledge the contributions of: Christopher
   Ferris, Huston Franklin, Alexey Melnikov, Bill Mills, and Roy T.
   Fielding.
























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Authors' Addresses

   Eamon O'Tuathail
   Clipcode.com
   24 Thomastown Road
   Dun Laoghaire
   Dublin
   IE

   Phone: +353 1 2350 424
   EMail: eamon.otuathail@clipcode.com
   URI:   http://www.clipcode.com/


   Marshall T. Rose
   Dover Beach Consulting, Inc.
   POB 255268
   Sacramento, CA  95865-5268
   US

   Phone: +1 916 483 8878
   EMail: mrose@dbc.mtview.ca.us





























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Full Copyright Statement

   Copyright (C) The Internet Society (2002).  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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