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<rfc category="std" docName="draft-xia-xrblock-rtcp-xr-layered-statistics-01"
     ipr="pre5378Trust200902">
  <front>
    <title abbrev="Layered Stream Statistics Report Blocks">RTCP XR Blocks for
    layered Stream statistics metric reporting</title>

    <author fullname="Jinwei Xia" initials="J." surname="Xia">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street>101 Software Avenue, Yuhua District</street>

          <city>Nanjing</city>

          <region>Jiangsu</region>

          <code>210012</code>

          <country>China</country>
        </postal>

        <email>xiajinwei@huawei.com</email>
      </address>
    </author>

    <author fullname="Glen Zorn" initials="G." surname="Zorn">
      <organization>Network Zen</organization>

      <address>
        <postal>
          <street>77/440 Soi Phoomjit, Rama IV Road</street>

          <street>Phra Khanong, Khlong Toie</street>

          <city>Bangkok</city>

          <code>10110</code>

          <country>Thailand</country>
        </postal>

        <phone>+66 (0) 87 502 4274</phone>

        <email>gwz@net-zen.net</email>
      </address>
    </author>

    <author fullname="Qin Wu" initials="Q." surname="Wu">
      <organization>Huawei</organization>

      <address>
        <postal>
          <street>101 Software Avenue, Yuhua District</street>

          <city>Nanjing</city>

          <region>Jiangsu</region>

          <code>210012</code>

          <country>China</country>
        </postal>

        <email>sunseawq@huawei.com</email>
      </address>
    </author>

    <author fullname="Roland Schott" initials="R." surname="Schott">
      <organization>Deutsche Telekom</organization>

      <address>
        <postal>
          <street>Deutsche-Telekom-Allee 7</street>

          <street></street>

          <city>Darmstadt</city>

          <code>64295</code>

          <country>Germany</country>
        </postal>

        <email>Roland.Schott@telekom.de</email>
      </address>
    </author>

    <date year="2011" />

    <abstract>
      <t>This document defines an RTCP XR Report Block and associated SDP
      parameters that allow the reporting of layered stream statistics metrics
      for use in a range of RTP applications.</t>
    </abstract>
  </front>

  <middle>
    <section title="Introduction">
      <t>This draft defines a new block type to augment those defined in <xref
      target="RFC3611"></xref>, for use in a range of RTP applications.
      <vspace blankLines="1" />The new block type provides layered streams
      statistics beyond the information carried in the Statistics Summary
      Report Block RTCP packet specified in the section 4.6 of RFC 3611 <xref
      target="RFC3611"></xref>. Information is recorded about lost layered
      component packets, duplicated layered component packets.<vspace
      blankLines="1" />The metrics belong to the class of transport level
      metrics defined in <xref target="MONARCH"></xref> (work in
      progress).</t>
    </section>

    <section title="Terminology">
      <section title="Standards Language">
        <t>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 <xref
        target="RFC2119">RFC 2119</xref>.</t>

        <t>In addition, the following terms are defined:</t>

        <t><list style="hanging">
            <t hangText="Layered Component Packet"><vspace blankLines="1" />a
            RTP packet using layered codecs containing the specified layered
            component, e.g., encoded stream at the base layer or at the
            enhancement layer.<vspace blankLines="1" /></t>
          </list></t>
      </section>
    </section>

    <section title="Applicability">
      <t>Layered Streams Statistics Metrics Block can be applied to any real
      time applications that use layered or multi-description video
      coding.</t>
    </section>

    <section anchor="LSSM" title="Layered Streams Statistics Metrics Block">
      <t>Metrics in this block report on lost packets, duplicated packets in
      the layered stream arriving at the RTP system.<vspace
      blankLines="1" /></t>

      <section title="Metric Block Structure">
        <t>The report block contents are dependent upon a series of flag bits
        carried in the first part of the header. Not all parameters need to be
        reported in each block. Flags indicate which are and which are not
        reported. The fields corresponding to unreported parameters MUST be
        present, but are set to zero. The receiver MUST ignore any Perceptual
        Quality Metrics Block with a non-zero value in any field flagged as
        unreported.</t>

        <t>The Layered Stream Statistics metrics Block has the following
        format:<figure>
            <artwork>   
    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=TBD    |I|T|D|   rsd.  |        block length           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        SSRC of source                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          begin_seq            |             end_seq           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                 Lost_Layered Component Packets                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Dup Layered Component_Packets                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
          </figure></t>
      </section>

      <section title="Definition of Fields in layered stream statistics Metrics Block">
        <t><list style="hanging">
            <t hangText="Block type (BT): 8 bits"><vspace blankLines="0" />
            The Layered stream Statistics Metrics Block is identified by the
            constant &lt;LSSM&gt;. <vspace blankLines="1" /></t>

            <t hangText="Interval Metric flag (I): 1 bit "><vspace
            blankLines="1" /> This field is used to indicate whether the Basic
            Loss/Discard metrics are Interval or Cumulative metrics, that is,
            whether the reported values applies to the most recent measurement
            interval duration between successive metrics reports (I=1) (the
            Interval Duration) or to the accumulation period characteristic of
            cumulative measurements (I=0) (the Cumulative Duration). <vspace
            blankLines="1" /></t>

            <t hangText="Layer Type flag (T): 1 bit"><vspace blankLines="0" />
            This field is used to indicate the Layer Type of layered video to
            be reported. LT is set to 0 if the loss_component_packet field and
            dup_component packet contain the base layer packet in layered
            codecs,e.g, SVC in <xref target="RFC6190"></xref>, 1 if the
            loss_component packet field and dup_component packet contain
            enhancement layer packet in layered codec. <vspace
            blankLines="1" /></t>

            <t hangText="Layer Dependency (D): 1 bit"><vspace
            blankLines="1" />This field is used to indicate the layer
            dependency between different enhancement layers if there is more
            than one enhancement layers. D is set to 0 if there is no layer
            dependency between different enhancement layers, 1 if there is
            layer dependency between different enhancement layers. <vspace
            blankLines="1" /></t>

            <t hangText="Rsd.: 5 bits"><vspace blankLines="0" /> 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.<vspace blankLines="1" /></t>

            <t hangText="Block length: 16 bits"><vspace blankLines="0" /> The
            constant 3, in accordance with the definition of this field in
            Section 3 of <xref target="RFC3611">RFC 3611</xref>. <vspace
            blankLines="1" /></t>

            <t hangText="begin_seq: 16 bits "><vspace blankLines="0" /> As
            defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
            <vspace blankLines="1" /></t>

            <t hangText="end_seq: 16 bits "><vspace blankLines="0" /> As
            defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
            <vspace blankLines="1" /></t>

            <t hangText="Lost_Layered Component Packets: 32 bits"><vspace
            blankLines="0" />Number of lost_component packets in the above
            sequence number interval.<vspace blankLines="1" /></t>

            <t hangText="Dup_Layered Component Packets: 32 bits"><vspace
            blankLines="0" />Number of dup_component packets in the above
            sequence number interval.</t>
          </list></t>
      </section>
    </section>

    <section title="SDP Signaling">
      <t>One new parameter is defined for the report block defined in this
      document to be used with Session Description Protocol (SDP) <xref
      target="RFC4566"></xref> using the Augmented Backus-Naur Form (ABNF)
      <xref target="RFC5234"></xref>. It has the following syntax within the
      "rtcp-xr" attribute <xref target="RFC3611"></xref>: <figure align="left">
          <artwork>
  rtcp-xr-attrib =  "a=rtcp-xr:"
                    [xr-format *(SP xr-format)] CRLF
        xr-format = layered-stream-stat-metrics
           layered-stream-stat-metrics = "layered-stream-stat-metrics"
                                ["=" stat-flag *("," stat-flag)]
                 stat-flag = "base layer packet"
                             / "enhancment layer packet"
</artwork>
        </figure> Refer to Section 5.1 of <xref target="RFC3611">RFC
      3611</xref> for a detailed description and the full syntax of the
      "rtcp-xr" attribute.</t>
    </section>

    <section title="IANA Considerations">
      <t>New report block type for RTCP XR is subject to IANA registration.
      For general guidelines on IANA allocations for RTCP XR, refer to <xref
      target="RFC3611">Section 6.2 of</xref>. <vspace blankLines="1" /> This
      document assigns one new block type value in the RTCP XR Block Type
      Registry: <list>
          <t><list hangIndent="12" style="hanging">
              <t hangText="Name:">LSSM</t>

              <t hangText="Long Name:">Layered Stream Statistics Metrics</t>

              <t hangText="Value">&lt;LSSM&gt;</t>

              <t hangText="Reference:"><xref target="LSSM"></xref> <vspace
              blankLines="1" /></t>
            </list></t>
        </list> This document also registers one new SDP <xref
      target="RFC4566"></xref> parameter for the "rtcp-xr" attribute in the
      RTCP XR SDP Parameters Registry: <list>
          <t><list style="symbols">
              <t>“layered-stream-stat-metrics”</t>
            </list></t>
        </list> <vspace blankLines="1" /> The contact information for the
      registrations is: <figure align="center">
          <artwork>
Qin Wu
sunseawq@huawei.com
101 Software Avenue, Yuhua District 
Nanjing, JiangSu 210012 China
</artwork>
        </figure></t>
    </section>

    <section title="Security Considerations">
      <t>The new RTCP XR report blocks proposed in this document introduces no
      new security considerations beyond those described in <xref
      target="RFC3611"></xref>.</t>
    </section>

    <section title="Acknowledgements">
      <t>The authors would like to thank Bill Ver Steeg, David R Oran, Ali
      Begen,Colin Perkins, Roni Even,Youqing Yang, Wenxiao Yu and Yinliang Hu
      for their valuable comments and suggestions on this document.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <reference anchor="RFC6190">
        <front>
          <title>RTP Payload Format for Scalable Video Coding</title>

          <author fullname="Stephan Wenger" initials="S" surname="Wenger">
            <organization></organization>
          </author>

          <author fullname="Ye-Kui Wang" initials="Y" surname="Wang">
            <organization></organization>
          </author>

          <author fullname="Thomas Schierl" initials="T" surname="Schierl">
            <organization></organization>
          </author>

          <author fullname="Alex Eleftheriadis" initials="A"
                  surname="Eleftheriadis">
            <organization></organization>
          </author>

          <date month="May" year="2011" />

          <abstract>
            <t>This memo describes an RTP payload format for Scalable Video
            Coding (SVC) as defined in Annex G of ITU-T Recommendation H.264,
            which is technically identical to Amendment 3 of ISO/IEC
            International Standard 14496-10. The RTP payload format allows for
            packetization of one or more Network Abstraction Layer (NAL) units
            in each RTP packet payload, as well as fragmentation of a NAL unit
            in multiple RTP packets. Furthermore, it supports transmission of
            an SVC stream over a single as well as multiple RTP sessions. The
            payload format defines a new media subtype name "H264-SVC", but is
            still backwards compatible to [I-D.ietf-avt-rtp-rfc3984bis] since
            the base layer, when encapsulated in its own RTP stream, must use
            the H.264 media subtype name ("H264") and the packetization method
            specified in [I- D.ietf-avt-rtp-rfc3984bis]. The payload format
            has wide applicability in videoconferencing, Internet video
            streaming, and high bit-rate entertainment-quality video, among
            others.Table of Contents</t>
          </abstract>
        </front>

        <seriesInfo name="RFC" value="6190" />

        <format target="http://www.rfc-editor.org/rfc/rfc6190.txt" type="TXT" />
      </reference>

      &rfc3611;

      &rfc2119;

      &rfc4566;

      &rfc5234;

      &rfc3550;
    </references>

    <references title="Informative References">
      <reference anchor="MONARCH">
        <front>
          <title>Monitoring Architectures for RTP</title>

          <author fullname="Qin Wu" initials="Q." surname="Wu">
            <organization>Huawei</organization>
          </author>

          <date month="April" year="2011" />
        </front>

        <seriesInfo name="ID" value="draft-ietf-avtcore-monarch-00" />

        <format type="TXT" />
      </reference>
    </references>

    <section title="Change Log">
      <section title="draft-xia-xrblock-rtcp-xr-layered-statistics-01">
        <t>The following are the major changes compared to previous version
        00: <list style="symbols">
            <t>Add the layer dependency field in the format of this metric
            block.</t>

            <t>Clear unused references.</t>

            <t>Other Editorial changes.</t>
          </list></t>
      </section>
    </section>
  </back>
</rfc>
