rfc3054.txt

最新的RFC

      |_____________________|_______ |_____________________________|
      | Basic DTMF Generator| dg     | REQUIRED                    |
      | Call Progress Tones | cg     | REQUIRED                    |
      |   Generator         |        |                             |
      |_____________________|________|_____________________________|

   Additional Packages not listed above MAY also be provided where
   applicable to audio input/output functions.

5.3.  RTP Termination Type

   Megaco IP Phone MGs MUST support at least one RTP Termination in
   order to support audio streams to/from the device, as defined in
   Megaco/H.248 Protocol Annex E.12 [3].

   No special TerminationID naming convention is defined for RTP
   Terminations as part of this specification.

6.  IPPhone Protocol Profile

   The following subsections provide details of the IPPhone Protocol
   Profile, used between Megaco IP Phone MGs and their controlling MGCs.
   This includes implicit application-level agreements between the
   Megaco IP Phone MG and its controlling MGC on organization and
   behavior of the MG, types of Terminations used and the specific
   minimum Package support for each, and specific minimum selections on
   the transport and encoding methods used.

   Use of a this Profile greatly simplifies assumptions necessary by the
   MGC regarding MG organization, thereby reducing complexity and cost
   of both MG and MGC, and improves interoperability for the specific
   Megaco IP Phone application.  Since the Profile is specific to the



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RFC 3054      Megaco IP Phone Media GW Application Profile  January 2001


   Megaco IP Phone MG, no other applications of Megaco/H.248 Protocol
   are affected.

   It is important to note that the IPPhone Profile specifies minimum
   functionality only, for interoperability purposes.  Additional
   Termination types, Package support, transport or encoding methods, or
   other capabilities MAY be added at the discretion of the implementer
   within the general structure described.

6.1.  Profile Descriptor and Usage

   Profile name: "IPPhone"
   Version: 1

   The Megaco/H.248 Protocol [3] describes startup and service change
   procedures in detail, including use of Profiles.

   In brief, the above Profile name and version are supplied by the
   Megaco IP Phone MG on startup or at service change, in the
   ServiceChangeDescriptor parameter of the ServiceChange command,
   issued to the controlling MGC as part of the registration procedure.
   In response, the MGC may 1) accept control by acknowledging the
   Service Change, 2) pass control to a different MGC by replying with a
   new MGC to try, or 3) refuse control entirely by rejecting the
   Service Change.  If MGC control is refused, the Megaco IP Phone MG
   may attempt registration with other MGCs in its list of MGCs to try.

   Once a controlling MGC accepts the IPPhone Profile, both it and the
   Megaco IP Phone MG become bound by the Profile rules and constraints
   described in subsequent subsections as well as Megaco IP Phone
   Termination/Package organization and behavior rules described in
   previous sections of this document.  Thereafter, any protocol use
   outside these rules is considered an error.

6.2 Termination Organization and Package Support

   Termination organization, required Termination types, and the
   specific Packages supported by each MUST be as described in sections
   4 - 5 of this document.

   Note that additional Termination types and Package support MAY also
   be provided within the general structure described.

6.3.  Transport

   Megaco IP Phone MGs MUST support Application Layer Framing (ALF) over
   UDP transport, as specified in the Megaco/H.248 Protocol Appendix D.1
   [3].



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RFC 3054      Megaco IP Phone Media GW Application Profile  January 2001


   Note that this does not imply that the Megaco IP Phone MG cannot
   support other transport methods as well.  TCP transport is OPTIONAL,
   but if used MUST conform to Megaco/H.248 Protocol Appendix D.2 [3].

6.4.  Message Encoding

   Megaco IP Phone MGs MUST support ABNF text encoding of the protocol,
   as specified in the Megaco/H.248 Protocol Appendix B [3].

   Note that this does not imply that the Megaco IP Phone MG cannot
   support ASN.1 binary encoding as well.  ASN.1 binary encoding is
   OPTIONAL, but if used MUST conform to Megaco/H.248 Protocol Appendix
   A [3].

7.  Security Considerations

   The Megaco IP Phone Media Gateway Application Profile adds no new
   security issues beyond those endemic to all applications of
   Megaco/H.248 Protocol [3].

8.  References

   [1] TIA/EIA, IS-811, Performance and Interoperability Requirements
       for Voice-over-IP (VoIP) Feature Telephones,
       http://www.tiaonline.org/standards/ip/voip/tia-eia-is-811-
       final.pdf

   [2] Greene, N., Ramalho, M. and B. Rosen, "Media Gateway Control
       Protocol Architecture and Requirements", RFC 2805, April 2000.

   [3] Cuervo, F., Greene, N., Rayhan, A., Huitema, C., Rosen, B. and J.
       Segers, "Megaco Protocol Version 1.0", RFC 3015, November 2000.

   [4] ITU-T SG16, H.248 Annex G: User Interface Elements and Actions
       Packages, Brown, M. & P. Blatherwick, November 2000.
       http://www.itu.int/itudoc/itu-t/rec/h/h248anxg.html

   [5] Bradner, S., "Key words for use in RFCs to Indicate Requirement
       Levels", BCP 14, RFC 2119, March 1997.












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9.  Authors' Addresses

   Peter Blatherwick (Editor)
   Nortel Networks
   P.O. Box 3511, Stn C
   Ottawa, Ontario,
   Canada K1Y 4H7

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


   Bob Bell
   Cisco Systems Inc.
   576 S. Brentwood Ln.
   Bountiful, UT 84010
   USA

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


   Phil Holland
   Circa Communications Ltd.
   1000 West 14th Street
   North Vancouver, British Columbia,
   Canada V7P 3P3

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



















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10.  Full Copyright Statement

   Copyright (C) The Internet Society (2001).  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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