Audio/Video Transport Working Group                              G. Hunt
Internet-Draft                                              Unaffiliated
Intended status: Standards Track                                A. Clark
Expires: July 15, 2012                                          Telchemy
                                                                   Q. Wu
                                                                  Huawei
                                                        January 12, 2012


 Measurement Identity and information Reporting using SDES item and XR
                                 Block
            draft-ietf-xrblock-rtcp-xr-meas-identity-02.txt

Abstract

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

Status of this Memo

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   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on July 15, 2012.

Copyright Notice

   Copyright (c) 2012 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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   include Simplified BSD License text as described in Section 4.e of



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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.


Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
     1.1.  RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . .  4
     1.2.  Performance Metrics Framework  . . . . . . . . . . . . . .  4
     1.3.  Applicability  . . . . . . . . . . . . . . . . . . . . . .  4
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  5
     2.1.  Standards Language . . . . . . . . . . . . . . . . . . . .  5
   3.  Measurement Identity SDES Item . . . . . . . . . . . . . . . .  6
     3.1.  APSI: Application Specific Identifier SDES Item  . . . . .  6
   4.  Measurement Information XR Block . . . . . . . . . . . . . . .  7
     4.1.  Report Block Structure . . . . . . . . . . . . . . . . . .  7
     4.2.  Definition of Fields in Measurement Information Report
           Block  . . . . . . . . . . . . . . . . . . . . . . . . . .  7
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  9
     5.1.  New RTCP SDES Type value . . . . . . . . . . . . . . . . .  9
     5.2.  New RTCP XR Block Type value . . . . . . . . . . . . . . .  9
     5.3.  Contact information for registrations  . . . . . . . . . .  9
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 10
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 11
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 11
     7.2.  Informative References . . . . . . . . . . . . . . . . . . 11
   Appendix A.  Change Log  . . . . . . . . . . . . . . . . . . . . . 12
     A.1.  draft-ietf-xrblock-xr-rtcp-meas-identity-00  . . . . . . . 12
     A.2.  draft-ietf-xrblock-xr-rtcp-meas-identity-01  . . . . . . . 12
     A.3.  draft-ietf-xrblock-xr-rtcp-meas-identity-02  . . . . . . . 12
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14




















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1.  Introduction

   This draft defines one new RTCP SDES item and one new XR Report Block
   to carry parameters which identify a measurement for use in a range
   of RTP applications.  The XR Report Block and the SDES item do not
   contain any measurement results (metrics).  However, the XR Report
   Block provides information relevant to a measurement reported in one
   or more other block types, including

   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].

   And the SDES item provides a measurement identity reported in one or
   more other block types, i.e.,a field for incorporation of an
   application-specific auxiliary identifier,

   The RTCP SDES item containing the measurement identity is intended to
   provide information to relate RTP to a non-RTP session while the RTCP
   XR Report Block containing the measurement information 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.

   A RTCP Measurement Identity SDES packet MAY be associated with a set
   of RTCP XR metrics blocks which share the same application specific
   measurement identifier.

   The RTCP XR Report Block MAY be associated with a set of RTCP XR
   metrics blocks which share the same information relevant to a
   reported measurement.  There MAY be several such sets in an RTCP
   packet, in which each set share the same information relevant to a
   reported measurement.  There MAY also be RTCP XR blocks in the packet
   which are not associated with a Measurement Information block, for
   example blocks which were defined before the Measurement Identity and



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   information mechanism was introduced by this document.

1.1.  RTCP and RTCP XR Reports

   The use of RTCP for reporting is defined in [RFC3550].  [RFC3611]
   defined an extensible structure for reporting using an RTCP Extended
   Report (XR).  This draft defines a new Extended Report block that
   MUST be used as defined in [RFC3550] and [RFC3611].

1.2.  Performance Metrics Framework

   The Performance Metrics Framework [RFC6390] provides guidance on the
   definition and specification of performance metrics.  The RTP
   Monitoring Architectures[MONARCH] provides guideline for reporting
   block format using RTCP XR .  Metrics or the SDES item described in
   this draft either reference external definitions or define metrics
   generally in accordance with [RFC6390] and [MONARCH].

1.3.  Applicability

   The RTCP SDES item and the RTCP XR block defined in this document
   provides information relevant to the measurement for members of a
   family of RTCP XR metrics blocks which are designed to use it.  To
   use the mechanism defined here, the RTCP XR block containing
   measurement information is not required to be in the same RTCP packet
   as the SDES item containing measurement identity.

























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2.  Terminology

2.1.  Standards Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119]












































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3.  Measurement Identity SDES Item

   This section defines the format of Measurement Identity SDES item.
   The SDES item is carried in the RTCP SDES packet.  The packet format
   for the RTCP SDES is defined in Section 6.5 of [RFC3550].  Each SDES
   packet is composed of a header with fixed-length fields for version,
   source count, packet type (PT), and length, followed by zero of more
   SDES items.  In the SDES packet, the PT field is set to SDES (202).

3.1.  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].  The identifier is variable length.
   Its length is described by the length field.  The value of the length
   field does not include the two octet SDES item header.  If no
   identifier is provided, the length field MUST be set to zero.  This
   item MUST be ignored by applications that are not configured to make
   use of it.
























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4.  Measurement Information XR Block

4.1.  Report Block Structure

   0               1               2               3
    0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     BT=NMI    |    Reserved   |      block length = 6         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    SSRC of stream source                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Reserved           |    first sequence number      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           extended first sequence number of interval          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 extended last sequence number                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Measurement Duration (Cumulative) (ms)               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |           Measurement Duration (Interval) (ms)                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                          Report Block Structure

4.2.  Definition of Fields in Measurement Information Report Block

   Block type (BT): 8 bits

      A Measurement Information Report Block is identified by the
      constant NMI.

      [Note to RFC Editor: please replace NMI with the IANA provided
      RTCP XR block type for this block.]


   Reserved.: 8 bits

      This field is reserved for future definition.  In the absence of
      such a definition, the bits in this field MUST be set to zero and
      MUST be ignored by the receiver.


   Block Length: 16 bits

      The length of this report block in 32-bit words minus one.  For
      the Measurement Information block, the block length is equal to 6.





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   SSRC of source: 32 bits

      As defined in Section 4.1 of [RFC3611].


   Reserved: 16 bits

      These bits are reserved.  They MUST be ignored by receivers.  They
      MUST be set to zero by senders.


   First sequence number: 16 bits

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


   Extended first sequence number of interval: 32 bits

      The extended RTP sequence number of the first received RTP packet
      of the current measurement interval.


   Extended last sequence number: 32 bits

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


   Measurement Duration (Cumulative) (ms): 32 bits

      The duration in ms of the reporting interval applicable to
      Cumulative reports which use this Measurement Information block.
      The value of this field can be calculated by receiver, for
      example, based on received RTP media packets or using RTCP method
      described in [RFC3550].


   Measurement Duration (Interval) (ms): 32 bits

      The duration in ms of the reporting interval applicable to
      Interval reports which use this Measurement Information block.
      The value of this field can be calculated by receiver, for
      example, based on received RTP media packets or using RTCP method
      described in [RFC3550].





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5.  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].

5.1.  New RTCP SDES Type value

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

   abbrev.      name                          value
   APSI: Application Specific Identifier       TBD

   [Note to RFC Editor: please replace APSI with the IANA provided RTCP
   SDES type for the SDES item.]

5.2.  New RTCP XR Block Type value

   This document assigns the block type value NMI in the IANA "RTCP XR
   Block Type Registry" to the "Measurement Information Block".

   [Note to RFC Editor: please replace NMI with the IANA provided RTCP
   XR block type for this block.]

5.3.  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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6.  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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7.  References

7.1.  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.

   [RFC3611]  Friedman, T., Caceres, R., and A. Clark, "RTP Control
              Protocol Extended Reports (RTCP XR)", November 2003.

7.2.  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.

   [RFC6390]  Clark, A. and B. Claise, "Framework for Performance Metric
              Development", RFC 6390, October 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-xr-rtcp-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.

A.2.  draft-ietf-xrblock-xr-rtcp-meas-identity-01

   The following are the major changes to
   draft-ietf-xrblock-xr-rtcp-meas-identity-00:

   o  Replace SDES item containing additional measurement information
      with XR Block.

   o  Add section 2 to describe following RFC2119 language.

   o  Add Section 1.2 to make SDES item and XR Report be compliant with
      RFC3550 and RFC3611

   o  Add Section 1.3 to make SDES item and XR Report follow Performance
      Metrics Framework and RTP Monitoring Architecture.

   o  Add section5.2 to register the new RTCP XR Block Type value.

   o  Remove RTCP SDES Type values that are needed.

A.3.  draft-ietf-xrblock-xr-rtcp-meas-identity-02

   The following are the major changes to
   draft-ietf-xrblock-xr-rtcp-meas-identity-01:

   o  Relocating information that belong to SDES item and XR Block
      respectively in the section 1.

   o  Rephrasing the text that describes SDES packet composition.





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   o  Rephrasing identifier description.

   o  Other Editorial changes.
















































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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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