Network Working Group                                       G. Zorn Zorn, Ed.
Internet-Draft                                               Network Zen
Intended status: Standards Track                               R. Schott
Expires: April 18, 25, 2013                                 Deutsche Telekom
                                                                   Q. Wu
                                                                R. Huang
                                                                  Huawei
                                                        October 15, 22, 2012

  RTP Control Protocol (RTCP) Extended Report (XR) Block Blocks for Summary
                      Statistics Metrics Reporting
               draft-ietf-xrblock-rtcp-xr-summary-stat-01
               draft-ietf-xrblock-rtcp-xr-summary-stat-02

Abstract

   This document defines three RTP Control Protcol (RTCP) Extended
   Report (XR) Blocks and associated SDP parameters that allows allow the
   reporting of loss, duplication and discard summary statistics metrics
   for use
   in a range of RTP applications.

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
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   This Internet-Draft will expire on April 18, 25, 2013.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  3
     2.1.  Standards Language . . . . . . . . . . . . . . . . . . . .  3
   3.  Transport Related End System Metrics . . . . . . . . . . . . .  4
     3.1.  Burst/Gap Loss Summary Statistics Block  . . . . . . . . .  4
       3.1.1.  Report Block Structure . . . . . . . . . . . . . . . .  4
       3.1.2.  Definition of Fields in Loss Summary Statistics
               Block  . . . . . . . . . . . . . . . . . . . . . . . .  4
     3.2.  Burst/Gap Discard Summary Statistics Block . . . . . . . .  6
       3.2.1.  Report Block Structure . . . . . . . . . . . . . . . .  6  7
       3.2.2.  Definition of Fields in inBurst/Gap Discard Summary
               Statistics Block . . . . . . . . . . . . . . . . . . . . . . . .  7
   4.  Application Level Metrics  . . . . . . . . . . . . . . . . . .  8
     4.1.  Frame Impairment Statistics Summary Block  . . . . . . . .  8  9
       4.1.1.  Report Block Structure . . . . . . . . . . . . . . . .  9
       4.1.2.  Definition of Fields in Frame Impairment Summary
               Statistics Block . . . . . . . . . . . . . . . . . . .  9
   5.  SDP Signaling  . . . . . . . . . . . . . . . . . . . . . . . . 11
     5.1.  SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 11
     5.2.  Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 11
   6.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11
     6.1.  New RTCP XR Block Type values  . . . . . . . . . . . . . . 11
     6.2.  New RTCP XR SDP Parameters . . . . . . . . . . . . . . . . 12
     6.3.  Contact information for registrations  . . . . . . . . . . 12
   7.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12
   8.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12
   9.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     9.1.  Normative References . . . . . . . . . . . . . . . . . . . 13
     9.2.  Informative References . . . . . . . . . . . . . . . . . . 13
   Appendix A.  Change Log  . . . . . . . . . . . . . . . . . . . . . 14
     A.1.  draft-ietf-xrblock-rtcp-xr-summary-stat-01 . . . . . . . . 14
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14

1.  Introduction

   This draft defines three new block types to augment those defined in
   Freidman, et al. [RFC3611] for use in a range of RTP applications.

   The first two block types support the reporting of burst gap loss/
   discard,
   discard summary statistics including packet loss/discard proportion,
   mean and variance and belong to the class of transport related transport-related end
   system metrics defined in [MONARCH]. Wu, Hunt & Arden
   [I-D.ietf-avtcore-monarch].  These two blocks are intended to be used
   in conjunction with information from the Burst Gap Loss metric block
   or Burst Gap Discard metric block, and on which these two block
   therefore depends.  However the depend.  The metrics in the Burst Gap Loss block or Burst
   Gap Discard metric block may can be used independently of the metrics
   defined in the first two blocks.These blocks, however.  These two blocks reflect
   transient IP problem problems that affect user experience and can be used to
   influence sender strategies to mitigate the problem.

   To form an accurate assessment of user users' quality of experience, it is
   therefore necessary to know not just overall rates of packet loss/
   discard, but also which frame type types were affected.  The third block
   supports the reporting of detailed statistics for each frame type,
   including the number of frames received, lost and discarded of each
   frame type in the Group of Pictures (GOP) and additional data
   allowing the calculation of statistical parameters (e.g.,the
   proportion of each frame type impaired by packet loss and discard).
   The metrics defined in this block belong to the class of application
   layer metrics defined in [MONARCH]. Wu, Hunt & Arden [I-D.ietf-avtcore-monarch].

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].

   In addition, the following terms are defined:

   Picture Type

      Picture types Types used in the different video algorithms compose are composed
      of the key-frame Key frame and the Derived frame.  Key-frame frames.  The Key frame is also called
      a reference frame and used as a reference for predicting other
      pictures.  It is coded without prediction from other pictures.
      The
      Derived frame is frames are derived from Key-frame a Key frame using a prediction from
      the reference frame.
      algorithm.

3.  Transport Related End System Metrics

3.1.  Burst/Gap Loss Summary Statistics Block

   The metrics described here are intended to be used as described in
   this section, in conjunction with information from the Measurement
   Information block [MEASIDENT] [I-D.ietf-xrblock-rtcp-xr-meas-identity] (which
   MUST be present in the same RTCP packet as the Burst/Gap Loss block)
   and also with the metric "cumulative number of packets lost" provided
   in standard RTCP [RFC3550].

   These metrics provide information relevant to statistical parameters,
   including burst loss rate, gap loss rate, burst duration mean, burst
   duration variance and are calculated using burst gap loss metrics
   defined in [BGLOSS] [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss] and other
   information which is sent together with this report block.

3.1.1.  Report Block Structure

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    BT=BGLSS   | I | Reserved  |        block length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         SSRC of Source                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |        Burst Loss Rate        |         Gap Loss Rate         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       Burst duration Mean     |    Burst duration Variance    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

3.1.2.  Definition of Fields in Loss Summary Statistics Block

   Block Type (BT): 8 bits

      Burst/Gap Loss Summary Statistics Block is identified by the
      constant <BGLSS>.

   Interval Metric flag (I): 2 bits

      This field is used to indicate whether the Burst/Gap Loss Summary
      Statistics metrics are Sampled, Interval or Cumulative metrics,
      that is, whether the reported values applies apply to the most recent
      measurement interval duration between successive metrics reports
      (I=10) (the Interval Duration) or to the accumulation period
      characteristic of cumulative measurements (I=11) (the Cumulative
      Duration) or is a sampled instantaneous value (I=01) (Sampled
      Value).

   Reserved: 6 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
      SHOULD be ignored by the receiver.

   Block Length: 16 bits

      The constant 3, in accordance with the definition of this field in
      Section 3 of RFC 3611 [RFC3611].

   SSRC of Source: 32 bits

      As defined in Section 4.1 of RFC3611 [RFC3611].

   Burst Loss Rate: 16 bits

      The fraction of packets lost during bursts since the beginning of
      reception, expressed as a fixed point number with the binary point
      at the left edge of the field.  This value is calculated by
      dividing Packets Loss in Bursts by Total Packets expected in
      Bursts as follows:

      Packets Loss in Bursts / Total Packets expected in Bursts

   Gap Loss Rate: 16 bits

      The fraction of packets lost during gaps since the beginning of
      reception expressed as a fixed point number with the binary point
      at the left edge of the field.  This value is calculated by
      dividing the difference between number of packets lost and Packets
      lost in Bursts by the difference between Packets Expected and
      Total Packets expected in Bursts as follows:

      (number of packets lost - Packets Lost in Bursts) / (Packets
      Expected - Total Packets expected in Bursts)

      where "number of packets lost" is obtained from standard RTCP
      [RFC3550] and Packets Expected is calculated as the difference
      between "extended last sequence number" and "extended first
      sequence number" (Interval or Cumulative) provided in the
      Measurement Identity and Information block [MEASIDENT].
      [I-D.ietf-xrblock-rtcp-xr-meas-identity].

      Note that if the metric is to be calculated on an Interval basis,
      a difference must be taken between the current and preceding
      values of "cumulative number of packets lost" in RTCP, to obtain
      the "number of packets lost" for the reporting interval.

   Burst Duration Mean:16bits

      The mean burst duration is obtained as the quotient:

      mean = Sum of Burst Durations / Number of Bursts

      where " Sum "Sum of Burst Durations " Durations" and "Number of Bursts"is Bursts" is obtained
      from the RTCP XR Burst/Gap Loss Block [BGLOSS].
      [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss].

   Burst Duration Variance:16bits

      The variance of the burst duration is obtained using the standard
      result:

      var = ( Sum of Squares of Burst Durations - Number of Bursts *
      mean^2 ) / (Number of Bursts - 1)

      where " Sum "Sum of Squares of Burst Durations " Durations" and "Number of Bursts"is
      obtained from the RTCP XR Burst/Gap Loss Block [BGLOSS].
      [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss].

3.2.  Burst/Gap Discard Summary Statistics Block

   The metrics described here are intended to be used as described in
   this section, in conjunction with information from the Measurement
   Identity block [MEASIDENT] [I-D.ietf-xrblock-rtcp-xr-meas-identity] (which MUST
   be present in the same RTCP packet as the Burst/Gap Discard Summary
   Statistics block) and also with the metric "number of packets
   discarded" provided in the RTCP XR Discard Block
   [DISCARD].
   [I-D.ietf-xrblock-rtcp-xr-discard].  The RTCP XR Discard Block SHOULD
   be sent if the Burst/Gap Discard Summary Statistics block is sent,
   but the converse does not apply.

   These metrics provide information relevant to statistical parameters,
   including burst discard rate, gap discard rate and are calculated
   using burst gap loss metrics defined in [BGDISCARD]
   [I-D.ietf-xrblock-rtcp-xr-burst-gap-discard] and other information
   which is sent together with this report block.

3.2.1.  Report Block Structure

      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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    BT=BGDSS   | I |  Reserved |        block length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          SSRC of Source                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          Burst Discard Rate   |        Gap Discard Rate       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

3.2.2.  Definition of Fields in inBurst/Gap Discard Summary Statistics
        Block

   Block Type (BT): 8 bits

      Burst/Gap Discard Summary Statistics Block is identified by the
      constant <BGDSS>.

   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.

   Interval Metric flag Type (I): 2 bits

      This field is used to indicate whether the Burst/Gap Discard
      Summary Statistics metrics are Sampled, Interval or Cumulative
      metrics, that is, whether the reported values applies to the most
      recent measurement interval duration between successive metrics
      reports (I=10) (the Interval Duration) or to the accumulation
      period characteristic of cumulative measurements (I=11) (the
      Cumulative Duration) or is a sampled instantaneous value (I=01)
      (Sampled Value).

   Reserved: 6 bits

      This field is used to indicate whether the Burst/Gap Discard
      Summary Statistics metrics are Sampled, Interval or Cumulative
      metrics, that is, whether reserved for future definition.  In the reported values applies to absence of
      such a definition, the most
      recent measurement interval duration between successive metrics
      reports (I=10) (the Interval Duration) or bits in this field MUST be set to zero and
      SHOULD be ignored by the accumulation
      period characteristic of cumulative measurements (I=11) (the
      Cumulative Duration) or is a sampled instantaneous value (I=01)
      (Sampled Value). receiver.

   Block Length: 16 bits

      The constant 2, in accordance with the definition of this field in
      Section 3 of RFC 3611 [RFC3611].

   SSRC of Source: 32 bits

      As defined in Section 4.1 of RFC3611 [RFC3611].

   Burst Discard Rate: 16 bits

      The fraction of packets discarded during bursts since the
      beginning of reception, expressed as a fixed point number with the
      binary point at the left edge of the field.  This value is
      calculated by dividing Packets Discarded in Bursts by Total
      Packets expected in Bursts as follows:

      Packets Discarded in Bursts / Total Packets expected in Bursts

   Gap Discard Rate: 16 bits

      The fraction of packets discarded during gaps since the beginning
      of reception expressed as a fixed point number with the binary
      point at the left edge of the field.  This value is calculated by
      dividing the difference between number of packets discarded and
      Packets Discarded in Bursts by the difference between Packets
      Expected and Total Packets expected in Bursts as follows:

      (number of packets discarded - Packets Discarded in Bursts) /
      (Packets Expected - Total Packets expected in Bursts)

      where "number of packets discarded" is obtained from the RTCP XR
      Discard Count Block [DISCARD] [I-D.ietf-xrblock-rtcp-xr-discard] and Packets
      Expected is calculated as the difference between "extended last
      sequence number" and "extended first sequence number" (Interval or
      Cumulative) provided in the Measurement Information block [MEASIDENT].
      [I-D.ietf-xrblock-rtcp-xr-meas-identity].  In order for
      Burst/Gap the Burst/
      Gap Discard Summary Statistics Block to be meaningful either

      1.  a single instance of the Discard Count block with DT=3 or
      2.  exactly 2 instances of the Discard Count block with DT=1 and
          DT=2, respectively

      MUST be included in the same RTCP compound packet.
      In this case,if  If a Discard
      Count (DT=3) Block block with DT=3 is received, "the number of packet discarded"is
      discarded" is be filled with the number of packets discarded due
      to both early and late arrival(DT=3); if Discard
      Count (DT=3) is not received, arrival; otherwise, "the number of packet
      discarded" is calculated as the sum of packet discards due to
      early arrival
      (DT=1)and (DT=1) and packet discards due to late arrival(DT=2). arrival
      (DT=2).

4.  Application Level Metrics
4.1.  Frame Impairment Statistics Summary Block

   This block reports statistics on which frame type were affected
   beyond the information carried in the Statistics Summary Report Block
   RTCP packet specified in the section 4.6 of RFC 3611 [RFC3611].
   Information is recorded about umber thenumber of frames received, lost frames
   ,duplicated
   frames, duplicated frames and lost partial frames.  Such information
   can be useful for network management and video quality monitoring.

4.1.1.  Report Block Structure

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     BT=FISS   |I|   Reserved  |        block length           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        SSRC of Source                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          Begin_seq            |             End_seq           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Number of frames received                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Discarded_frames                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Dup_frames                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Lost_full_frames                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Lost_partial_frames                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

4.1.2.  Definition of Fields in Frame Impairment Summary Statistics
        Block

   Block type (BT): 8 bits

      Frame Impairment Statistics Summary Block is identified by the
      constant <FISS>.

   Picture type indicator (I): 1 bit

      Picture types used in the different video algorithms compose of
      key-frame and derivation frame.

      This field is used to indicate the frame type to be reported.  Bits  The
      bit is set to 0 if the lost_frames
      field or lost_full_frames, lost_partial_frames and
      dup_frames field fields contain a key_frame report or reference Key frame report, (reference frame) counts or 1
      if the lost_frames field and dup_frames field they contain other derivation Derivation frame report. counts.  Note that if both the key
      Key frame report and derivation Derivation frame report are sent, they should be
      sent in the same RTCP compound packet using two XR Frame Impairment
      Summary Statistics Blocks.

   Reserved: 7 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
      SHOULD be ignored by the receiver.

   Block Length: 16 bits

      The constant 7, in accordance with the definition of this field in
      Section 3 of RFC 3611 [RFC3611].

   SSRC of Source: 32 bits

      As defined in Section 4.1 of RFC3611 [RFC3611].

   Begin_seq: 16 bits

      As defined in Section 4.1 of RFC 3611 [RFC3611].

   end_seq: 16 bits

      As defined in Section 4.1 of RFC 3611 [RFC3611].

   Number of frames received:32bits received:32 bits

      A count of the number of frames received, received in the above sequence
      number interval, estimated if necessary.  If no frames have been
      received then this count shall SHALL be set to
      Zero. zero.

   Number of discarded frames (discarded_frames): 32 bits

      Number of frames discarded in the above sequence number interval.

   Number of duplicated duplicate frames (dup_frames): 32 bits

      Number of duplicated duplicate frames received in the above sequence number
      interval.

   Number of full frames lost (lost_full_frames): 32 bits

      If one frame is completely lost, this frame is regarded as one
      lost full_frame. full frame.  The lost_full_frames is equivalent to the number
      of full frames lost in the above sequence number interval.

   Number of partial frames lost (lost_partial_frames): 32 bits

      If one frame is partially lost, this frame is regarded as one lost
      fractional frame.  The value of the lost_partial_frames field is
      equivalent to the number of partial_frames partial frames lost in the above
      sequence number interval.

5.  SDP Signaling

   [RFC3611]

   RFC 3611 defines the use of SDP (Session Description Protocol)
   [RFC4566] for signaling the use of XR blocks.  XR blocks MAY be used
   without prior signaling.

5.1.  SDP rtcp-xr-attrib Attribute Extension

   This section augments the SDP [RFC4566] attribute "rtcp-xr" defined
   in [RFC3611] Section 5.1 of RFC 3611 by providing three additional value values of
   "xr-format" to signal the use of the report block defined in this
   document.

            xr-format = / burst-gap-loss-stat
                        / burst-gap-discard-stat
                        / frame-impairment-stat
    Burst-gap-loss-stat ="burst gap loss summary statistics"
    Burst-gap-discard-stat="burst gap discard summary statistics"
    Frame-impairment-stat="frame impairment summary statistics"

5.2.  Offer/Answer Usage

   When SDP is used in offer-answer context, the SDP Offer/Answer usage
   defined in [RFC3611] Section 5.2 of RFC 3611 applies.

6.  IANA Considerations

   New block types for RTCP XR are subject to IANA registration.  For
   general guidelines on IANA considerations for RTCP XR, refer
   to[RFC3611] . to RFC
   3611.

6.1.  New RTCP XR Block Type values

   This document assigns three new block type value in the RTCP XR Block
   Type Registry:

         Name:       BGLSS
         Long Name:  Burst/Gap Loss Summsary Statistics Block
         Value       <BGLSS>
         Reference:  Section 3.1

         Name:       BGDSS
         Long Name:  Burst/Gap Discard Summary Statistics Block
         Value       <BGDSS>
         Reference:  Section 3.2

         Name:       FISS
         Long Name:  Frame Impairment Statistics Summary
         Value       <FISS>
         Reference:  Section 4.1

6.2.  New RTCP XR SDP Parameters

   This document also registers three new SDP [RFC4566] parameters for
   the "rtcp-xr" attribute in the RTCP XR SDP Parameters Registry:

    *  " burst-gap-loss-stat "
    *  " burst-gap-discard-stat "
    *  " frame-impairment-stat "

6.3.  Contact information for registrations

   The contact information for the registrations is:

       Glen Zorn
       Network Zen
       227/358 Thanon Sanphawut
       Bang Na, Bangkok  10110  10260
       Thailand

7.  Security Considerations

   The new RTCP XR report blocks proposed in this document introduces no
   new security considerations beyond those described in [RFC3611]. RFC 3611.

8.  Acknowledgements

   The authors would like to thank Bill Ver Steeg, David R Oran, Ali
   Begen,Colin
   Begen, Colin Perkins, Roni Even,Youqing Even, Youqing Yang, Wenxiao Yu, Yinliang
   Hu,Jing
   Hu, Jing Zhao and Brandenburg, R. (Ray) Ray van Brandenburg for their valuable comments and
   suggestions on this document.

9.  References

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC3550]  Schulzrinne, H., Casner, S., Frederick, R., and V.
              Jacobson, "RTP: A Transport Protocol for Real-Time
              Applications", STD 64, RFC 3550, July 2003.

   [RFC3611]  Friedman, T., Caceres, R., and A. Clark, "RTP Control
              Protocol Extended Reports (RTCP XR)", RFC 3611,
              November 2003.

   [RFC4566]  Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
              Description Protocol", RFC 4566, July 2006.

9.2.  Informative References

   [BGDISCARD]

   [I-D.ietf-avtcore-monarch]
              Wu, W., Hunt, G., "RTCP XR and P. Arden, "Guidelines for Use of the
              RTP Monitoring Framework", draft-ietf-avtcore-monarch-22
              (work in progress), September 2012.

   [I-D.ietf-xrblock-rtcp-xr-burst-gap-discard]
              Clark, A., Huang, R., and W. Wu, "RTP Control
              Protocol(RTCP) Extended Report (XR) Block for Burst Gap Discard
              Count metric Reporting",
              ID draft-ietf-xrblock-rtcp-xr-burst-gap-discard-09,
              draft-ietf-xrblock-rtcp-xr-burst-gap-discard-06 (work in
              progress), October 2012.

   [BGLOSS]   Hunt, G., "RTCP XR

   [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss]
              Clark, A., Zhang, S., Zhao, J., and W. Wu, "RTP Control
              Protocol (RTCP) Extended Report (XR) Block for Burst Gap Burst/Gap
              Loss metric Reporting",
              ID draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04,
              draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 (work in
              progress), October 2012.

   [DISCARD]  Hunt,

   [I-D.ietf-xrblock-rtcp-xr-discard]
              Clark, A., Zorn, G., "RTCP XR and W. Wu, "RTP Control Protocol
              (RTCP) Extended Report (XR) Block for Discard Count metric
              Reporting", ID draft-ietf-xrblock-rtcp-xr-discard-09, draft-ietf-xrblock-rtcp-xr-discard-09 (work in
              progress), October 2012.

   [MEASIDENT]

   [I-D.ietf-xrblock-rtcp-xr-meas-identity]
              Clark, A. and W. Wu, Q., "Measurement Identity and information
              Reporting using SDES item and XR Block",
              ID draft-ietf-xrblock-rtcp-xr-meas-identity-10,
              draft-ietf-xrblock-rtcp-xr-meas-identity-10 (work in
              progress), August 2012.

   [MONARCH]  Wu, Q., "Monitoring Architecture for RTP",
              ID draft-ietf-avtcore-monarch-22, September 2012.

   [RFC6390]  Clark, A., "Framework for Performance Metric Development",
              RFC 6390, January 2011.

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-xr-summary-stat-01

   The following are the major changes compared to 00:
   o  Outdated Reference update
   o  Add text to clarify the selection of discard count based on
      discard count metric block.
   o  Revise Interval metric flag defintion for consistency.
   o  SDP text restructure
   o  Other editorial changes based on comments on the list.

Authors' Addresses

   Glen Zorn (editor)
   Network Zen
   77/440 Soi Phoomjit, Rama IV Road
   Phra Khanong, Khlong Toie
   227/358 Thanon Sanphawut
   Bang Na, Bangkok  10110  10260
   Thailand

   Phone: +66 (0) 87 502 4274 909-201060
   Email: gwz@net-zen.net glenzorn@gmail.com

   Roland Schott
   Deutsche Telekom
   Deutsche-Telekom-Allee 7
   Darmstadt  64295
   Germany

   Email: Roland.Schott@telekom.de
   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: sunseawq@huawei.com

   Rachel Huang
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing  210012
   China

   Email: Rachel@huawei.com