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Versions: 00 01 02 03 04 05 06 07 08 09 RFC 6776

Audio/Video Transport Working Group                              G. Hunt
Internet-Draft                                              Unaffiliated
Intended status: Standards Track                                A. Clark
Expires: March 29, 2012                                         Telchemy
                                                                   Q. Wu
                                                                  Huawei
                                                      September 26, 2011


     RTCP Source Description (SDES) items for Measurement Identity
            draft-ietf-xrblock-rtcp-xr-meas-identity-00.txt

Abstract

   This document defines RTCP SDES items carrying parameters which
   identify a measurement, to which one or more other RTCP XR Report
   Blocks may refer.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
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   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 29, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   publication of this document.  Please review these documents
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  Applicability  . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Measurement Identity SDES Items  . . . . . . . . . . . . . . .  4
     2.1.  APSI: Application Specific Identifier SDES Item  . . . . .  4
     2.2.  EXFS: extended first sequence number SDES Item . . . . . .  4
     2.3.  EXLS: extended last sequence number SDES Item  . . . . . .  5
     2.4.  CUMD: Cumulative  Measurement Duration SDES Item . . . . .  5
     2.5.  INMD: Interval Measurement Duration SDES Item  . . . . . .  5
   3.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  6
     3.1.  New RTCP SDES Type value . . . . . . . . . . . . . . . . .  6
     3.2.  New RTCP XR SDP Parameter  . . . . . . . . . . . . . . . .  6
     3.3.  Contact information for registrations  . . . . . . . . . .  6
   4.  Security Considerations  . . . . . . . . . . . . . . . . . . .  7
   5.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  8
     5.1.  Normative References . . . . . . . . . . . . . . . . . . .  8
     5.2.  Informative References . . . . . . . . . . . . . . . . . .  8
   Appendix A.  Change Log  . . . . . . . . . . . . . . . . . . . . .  9
     A.1.  draft-ietf-xrblock-rtcp-sdes-meas-identity-00  . . . . . .  9
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10



























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1.  Introduction

   This draft defines new RTCP SDES items to carry parameters which
   identify a measurement for use in a range of RTP applications.  These
   SDES items do not itself contain any measurement results (metrics).
   However, they provide information relevant to a measurement reported
   in one or more other block types, including

   o  a field for incorporation of an application-specific auxiliary
      identifier,

   o  the sequence number of the first packet of the RTP session,

   o  the extended sequence numbers of the first packet of the current
      measurement interval, and the last packet included in the
      measurement,

   o  the duration of the most recent measurement interval and

   o  the duration of the interval applicable to cumulative measurements
      (which may be the duration of the RTP session to date).

   The method for calculation of the extended RTP sequence number is
   provide in [RFC3550].

   The RTCP SDES packet containing these item is intended to provide a
   single copy of the information necessary to relate measurement data
   in the RTCP XR blocks to the stream, and measurement period, to which
   they refer.  Commonly, multiple other small metric blocks contain
   measurement data for the same stream and period, and it would be a
   large overhead if all of these metric blocks carried duplicated data
   for measurement identification.  Other blocks make a reference to
   this block (by SSRC).  A Measurement Identity SDES packet is
   associated with the set of RTCP XR metrics blocks which share the
   same SSRC value.  There MAY be several such sets in an RTCP packet,
   up to a limit of 8 arising from the use of 3-bit tags.  There MAY
   also be RTCP XR blocks in the packet which are not associated with a
   Measurement Identity block, for example blocks which were defined
   before the Measurement Identity mechanism was introduced by this
   document.

1.1.  Applicability

   The RTPC SDES items provide identification information for members of
   a family of RTCP XR metrics blocks which are designed to use it.  To
   use the mechanism defined here, a metrics block must be in the same
   RTCP packet as the SDES packet for Measurement Identity.




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2.  Measurement Identity SDES Items

   This section defines the format of Measurement Identity SDES items.
   These SDES items are carried in the RTCP SDES packet.  The packet
   format for the RTCP SDES is defined in Section 6.5 of [RFC3550].
   Each SDES packet has a fixed-length field for version,source count,
   parcket type (PT), length as well as a variable-length field for SDES
   items.  In the SDES packets, the PT field is set to SDES (202).

2.1.  APSI: Application Specific Identifier SDES Item

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    APSI=TBD   |     length    |application specific identifier
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   ....
      +-+-+-+-+-+-+-+-+

   Application specific identifier is an additional identifier which is
   useful in the context of a specific application, e.g. an MPEG-2
   transport identifier [MPEG2].  Where the identifier is less than 32
   bits, the identifier SHOULD be mapped into the most significant bits
   of the field.  If no additional identifier is provided, all bits of
   the field MUST be set to zero.  This field MUST be ignored by
   applications which are not configured to make use of it.

2.2.  EXFS: extended first sequence number SDES Item

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    APSI=TBD   |     length    | extended first sequence number
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   of interval ....
      +-+-+-+-+-+-+-+-+

   The RTP sequence number of the first received RTP packet of the
   session, used to determine the number of packets contributing to
   cumulative measurements.











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2.3.  EXLS: extended last sequence number SDES Item

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    APSI=TBD   |     length    | extended last sequence number
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   ....
      +-+-+-+-+-+-+-+-+

   The extended RTP sequence number of the last received RTP packet
   which contributed to this measurement.

2.4.  CUMD: Cumulative  Measurement Duration SDES Item

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    APSI=TBD   |     length    | Measurement Duration (Cumulative)
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   (ms) ....
     +-+-+-+-+-+-+-+-+

   The duration in ms of the reporting interval applicable to Cumulative
   reports which use this Measurement Identity block.

2.5.  INMD: Interval Measurement Duration SDES Item

       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    APSI=TBD   |     length    | Measurement Duration (Interval)
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   (ms) ....
      +-+-+-+-+-+-+-+-+

   The duration in ms of the reporting interval applicable to Interval
   reports which use this Measurement Identity block.













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3.  IANA Considerations

   New SDES types for RTCP SDES are subject to IANA registration.  For
   general guidelines on IANA considerations for RTCP SDES, refer to
   [RFC3550].

3.1.  New RTCP SDES Type value

   This document assigns additional five SDES types in the IANA "RTCP XR
   Block Type Registry" to the Measurement Identity SDES items as
   follow:

   abbrev.      name                          value
   APSI: Application Specific Identifier       TBD
   EXFS: extended first sequence number        TBD
   EXLS: extended last sequence number         TBD
   CUMD: Cumulative  Measurement Duration      TBD
   INMD: Interval Measurement Duration         TBD

   [Note to RFC Editor: please replace APSI,EXF,EXLS,CUMD,INMD with the
   IANA provided RTCP SDES type for these SDES items.]

3.2.  New RTCP XR SDP Parameter

   This document also registers a new parameter "jitter-bfr" in the
   "RTCP XR SDP Parameters Registry".

3.3.  Contact information for registrations


   The contact information for the registrations is:

   Qin Wu (sunseawq@huawei.com)

   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China














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4.  Security Considerations

   RTCP reports can contain sensitive information since they can provide
   information about the nature and duration of a session established
   between two or more endpoints.Therefore, the use of security
   mechanisms with RTP documented in Section 9 of [RFC3550] should
   apply.












































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5.  References

5.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", March 1997.

   [RFC3550]  Schulzrinne, H., "RTP: A Transport Protocol for Real-Time
              Applications", RFC 3550, July 2003.

5.2.  Informative References

   [MONARCH]  Wu, Q., "Monitoring Architectures for RTP",
              ID draft-ietf-avtcore-monarch-04, August 2011.

   [MPEG2]    "ISO/IEC, "Standard 13818-1"", December 2000.

   [PMOLFRAME]
              Clark, A. and B. Claise, "Framework for Performance Metric
              Development", ID draft-ietf-pmol-metrics-framework-12,
              July 2011.






























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Appendix A.  Change Log

   Note to the RFC-Editor: please remove this section prior to
   publication as an RFC.

A.1.  draft-ietf-xrblock-rtcp-sdes-meas-identity-00

   The following are the major changes to
   draft-ietf-avt-rtcp-xr-meas-identity-02:

   o  Change the use of SDES item to convey measurement identity instead
      of XR Block in section 2.

   o  Update references.

   o  Update security section and remove SDP signaling section.



































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Authors' Addresses

   Geoff Hunt
   Unaffiliated

   Email: r.geoff.hunt@gmail.com


   Alan Clark
   Telchemy Incorporated
   2905 Premiere Parkway, Suite 280
   Duluth, GA  30097
   USA

   Email: alan.d.clark@telchemy.com


   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: sunseawq@huawei.com



























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