One document matched: draft-ietf-xrblock-rtcp-xr-jb-02.xml

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<rfc category="std" docName="draft-ietf-xrblock-rtcp-xr-jb-02.txt"
     ipr="trust200902">
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  <front>
    <title abbrev="RTCP XR Jitter Buffer">RTP Control Protocol (RTCP) Extended
    Report (XR) Block for Jitter Buffer Metric Reporting</title>

    <author fullname="Alan Clark" initials="A." surname="Clark">
      <organization abbrev="Telchemy">Telchemy Incorporated</organization>

      <address>
        <postal>
          <street>2905 Premiere Parkway, Suite 280</street>

          <city>Duluth</city>

          <region>GA</region>

          <code>30097</code>

          <country>USA</country>
        </postal>

        <email>alan.d.clark@telchemy.com</email>
      </address>
    </author>

    <author fullname="Varun Singh" initials="V" surname="Singh">
      <organization>Aalto University</organization>

      <address>
        <postal>
          <street>School of Electrical Engineering</street>

          <street>Otakaari 5 A</street>

          <city>Espoo</city>

          <region>FIN</region>

          <code>02150</code>

          <country>Finland</country>
        </postal>

        <email>varun@comnet.tkk.fi</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>

    <date year="2012" />

    <area>Real-time Applications and Infrastructure Area</area>

    <workgroup>Audio/Video Transport Working Group</workgroup>

    <keyword>RFC</keyword>

    <keyword>Request for Comments</keyword>

    <keyword>I-D</keyword>

    <keyword>Internet-Draft</keyword>

    <keyword>Real Time Control Protocol</keyword>

    <abstract>
      <t>This document defines an RTP Control Protocol (RTCP) Extended Report
      (XR) Block that allows the reporting of Jitter Buffer metrics for a
      range of RTP applications.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <section title="Jitter Buffer Metrics Block">
        <t>This document defines a new block type to augment those defined in
        <xref target="RFC3611"></xref>, for use in a range of RTP
        applications.</t>

        <t>The new block type provides information on jitter buffer
        configuration and performance.</t>

        <t>The metric belongs to the class of transport-related end system
        metrics defined in <xref target="RFC6792"></xref>.</t>

        <t>Instances of this Metrics Block refer by SSRC to the separate
        auxiliary Measurement Information block <xref target="RFC6776"></xref>
        which contains information such as the SSRC of the measured stream,
        and RTP sequence numbers and time intervals indicating the span of the
        report.</t>
      </section>

      <section title="RTCP and RTCP XR Reports">
        <t>The use of RTCP for reporting is defined in <xref
        target="RFC3550"></xref>. <xref target="RFC3611"></xref> defined an
        extensible structure for reporting using an RTCP Extended Report (XR).
        This document defines a new Extended Report block for use with <xref
        target="RFC3550"></xref> and <xref target="RFC3611"></xref>.</t>
      </section>

      <section title="Performance Metrics Framework">
        <t>The Performance Metrics Framework <xref target="RFC6390"></xref>
        provides guidance on the definition and specification of performance
        metrics. The RTP Monitoring Architectures <xref
        target="RFC6792"></xref> provides guideline for reporting block format
        using RTCP XR. Metrics described in this draft are in accordance with
        the guidelines in <xref target="RFC6390"></xref><xref
        target="RFC6792"></xref>.</t>
      </section>

      <section title="Applicability">
        <t>Real-time applications employ a jitter buffer to smooth out jitter
        encountered on the path from source to destination. These metrics are
        used to measure how the jitter buffer behave as a result of the jitter
        and applicable to a range of RTP applications. These metrics reflect
        terminal related factor that most affects real-time application
        quality and useful to provide more precise estimation for user
        experience to the quality of real-time application performance and
        also valuable to network manager in troubleshooting network.</t>
      </section>
    </section>

    <section title="Jitter Buffer Metrics Block">
      <t>This block describes the configuration and operating parameters of
      the jitter buffer in the receiver of the RTP end system or RTP mixer
      which sends the report. Instances of this Metrics Block refer by SSRC to
      the separate auxiliary Measurement Information block <xref
      target="RFC6776"></xref> which contains measurement intervals. This
      metric block relies on the measurement interval in the Measurement
      Information block indicating the span of the report and should be sent
      in the same compound RTCP packet as the measurement information block.
      If the measurement interval is not received in the same compound RTCP
      packet as this metric block, this metric block should be discarded.</t>

      <section title="Report Block Structure">
        <t>JB Metrics Block<figure title="Figure 1: Report Block Structure">
            <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=NJB    | I |jb cfg |rsv|       block length=3          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           SSRC of Source                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |          JB nominal           |         JB maximum            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     JB high water mark        |      JB low water mark        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
          </figure></t>
      </section>

      <section title="Definition of Fields in Jitter Buffer Metrics Block">
        <t><list style="hanging">
            <t hangText="Block type (BT): 8 bits"><vspace blankLines="1" /> A
            Jitter Buffer Metrics Report Block is identified by the constant
            NJB.<vspace blankLines="1" /> [Note to RFC Editor: please replace
            NJB with the IANA provided RTCP XR block type for this
            block.]<vspace blankLines="1" /></t>

            <t hangText="Interval Metric flag (I): 2 bits"><vspace
            blankLines="1" />This field is used to indicate whether the Jitter
            Buffer metrics are Sampled, Interval or Cumulative metrics: <list>
                <t>I=10: Interval Duration - the reported value applies to the
                most recent measurement interval duration between successive
                metrics reports.</t>

                <t>I=11: Cumulative Duration - the reported value applies to
                the accumulation period characteristic of cumulative
                measurements.</t>

                <t>I=01: Sampled Value - the reported value is a sampled
                instantaneous value.</t>
              </list><vspace blankLines="1" /></t>

            <t hangText="Jitter Buffer Configuration (jb cfg): 4 bits"><vspace
            blankLines="1" /> This field is used to identify the jitter buffer
            method in use at the receiver, according to the following
            code:<list>
                <t>bits 014-011<list>
                    <t>0 = Fixed jitter buffer</t>

                    <t>1 = Adaptive jitter buffer</t>

                    <t>Other values reserved</t>
                  </list></t>
              </list><vspace blankLines="1" /></t>

            <t hangText="Reserved (rsv): 2 bits"><vspace
            blankLines="1" />These bits are reserved. They MUST be set to zero
            by senders ignored by receivers (See RFC6709 section 4.2). <vspace
            blankLines="1" /></t>

            <t hangText="Block Length: 16 bits"><vspace blankLines="1" />The
            length of this report block in 32-bit words, minus one and MUST be
            set to 3, in accordance with the definition of this field in <xref
            target="RFC3611"></xref>. The block MUST be discarded if the block
            length is set to a different value. <vspace blankLines="1" /></t>

            <t
            hangText="jitter buffer nominal delay (JB nominal): 16 bits"><vspace
            blankLines="1" />This is the current nominal jitter buffer delay
            in milliseconds, which corresponds to the nominal jitter buffer
            delay for packets that arrive exactly on time. It is calculated
            based on the time for packets spent in the jitter buffer. This
            parameter MUST be provided for both fixed and adaptive jitter
            buffer implementations.<vspace blankLines="1" />If the measured
            value exceeds 0xFFFD, the value 0xFFFE SHOULD be reported to
            indicate an over-range measurement. If the measurement is
            unavailable, the value 0xFFFF SHOULD be reported.<vspace
            blankLines="1" /></t>

            <t
            hangText="jitter buffer maximum delay (JB maximum): 16 bits"><vspace
            blankLines="1" />This is the current maximum jitter buffer delay
            in milliseconds which corresponds to the earliest arriving packet
            that would not be discarded. In simple queue implementations this
            may correspond to the nominal size. In adaptive jitter buffer
            implementations, this value may dynamically. This parameter MUST
            be provided for both fixed and adaptive jitter buffer
            implementations.<vspace blankLines="1" />If the measured value
            exceeds 0xFFFD, the value 0xFFFE SHOULD be reported to indicate an
            over-range measurement. If the measurement is unavailable, the
            value 0xFFFF SHOULD be reported.<vspace blankLines="1" /></t>

            <t
            hangText="jitter buffer high water mark (JB high water mark): 16 bits"><vspace
            blankLines="1" /> This is the highest value of the jitter buffer
            nominal delay in milliseconds which occurred at any time during
            the reporting interval.<vspace blankLines="1" />If the measured
            value exceeds 0xFFFD, the value 0xFFFE SHOULD be reported to
            indicate an over-range measurement. If the measurement is
            unavailable, the value 0xFFFF SHOULD be reported.<vspace
            blankLines="1" /></t>

            <t
            hangText="jitter buffer low water mark (JB low water mark): 16 bits"><vspace
            blankLines="1" />This is the lowest value of the jitter buffer
            nominal delay in milliseconds which occurred at any time during
            the reporting interval.<vspace blankLines="1" /> If the measured
            value exceeds 0xFFFD, the value 0xFFFE SHOULD be reported to
            indicate an over-range measurement. If the measurement is
            unavailable, the value 0xFFFF SHOULD be reported.<vspace
            blankLines="1" /></t>
          </list></t>
      </section>
    </section>

    <section title="SDP Signaling">
      <t>[RFC3611] defines the use of SDP (Session Description Protocol) <xref
      target="RFC4566"></xref> for signaling the use of XR blocks. XR blocks
      MAY be used without prior signaling.</t>

      <section title="SDP rtcp-xr-attrib Attribute Extension">
        <t>This section augments the SDP <xref target="RFC4566"></xref>
        attribute "rtcp-xr" defined in <xref target="RFC3611"></xref> by
        providing an additional value of "xr-format" to signal the use of the
        report block defined in this document.<figure>
            <artwork>
xr-format =/ xr-jb-block

xr-jb-block = "jitter-bfr"
</artwork>
          </figure></t>
      </section>

      <section title="Offer/Answer Usage">
        <t>When SDP is used in offer-answer context, the SDP Offer/Answer
        usage defined in <xref target="RFC3611"></xref> for unilateral
        "rtcp-xr" attribute parameters applies. For detailed usage in
        Offer/Answer for unilateral parameter, refer to section 5.2 of <xref
        target="RFC3611"></xref>.</t>
      </section>
    </section>

    <section title="IANA Considerations">
      <t>New block types for RTCP XR are subject to IANA registration. For
      general guidelines on IANA considerations for RTCP XR, refer to <xref
      target="RFC3611"></xref>.</t>

      <section title="New RTCP XR Block Type value">
        <t>This document assigns the block type value NJB in the IANA "RTCP XR
        Block Type Registry" to the "JB Metrics Block".</t>

        <t>[Note to RFC Editor: please replace NJB with the IANA provided RTCP
        XR block type for this block.]</t>
      </section>

      <section title="New RTCP XR SDP Parameter">
        <t>This document also registers a new parameter "jitter-bfr" in the
        "RTCP XR SDP Parameters Registry".</t>
      </section>

      <section title="Contact information for registrations">
        <t><figure>
            <artwork>
   The contact information for the registrations is:

   Qin Wu (sunseawq@huawei.com)
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China
</artwork>
          </figure><vspace blankLines="1" /></t>
      </section>
    </section>

    <section title="Security Considerations">
      <t>It is believed that this proposed RTCP XR report block introduces no
      new security considerations beyond those described in <xref
      target="RFC3611"></xref>. This block does not provide per-packet
      statistics so the risk to confidentiality documented in Section 7,
      paragraph 3 of <xref target="RFC3611"></xref> does not apply.</t>
    </section>

    <section title="Contributors">
      <t>Geoff Hunt wrote the initial draft of this document.</t>
    </section>

    <section title="Acknowledgments">
      <t>The authors gratefully acknowledge reviews and feedback provided by
      Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor, Claus
      Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, Tom Hock,
      Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, Mohamed Mostafa,
      Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi Raviraj, Albrecht
      Schwarz, Tom Taylor, and Hideaki Yamada.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <reference anchor="RFC2119">
        <front>
          <title abbrev="RFC Key Words">Key words for use in RFCs to Indicate
          Requirement Levels</title>

          <author fullname="Scott Bradner" initials="S." surname="Bradner">
            <organization>Harvard University</organization>

            <address>
              <postal>
                <street>1350 Mass. Ave.</street>

                <street>Cambridge</street>

                <street>MA 02138</street>
              </postal>

              <phone>- +1 617 495 3864</phone>

              <email>sob@harvard.edu</email>
            </address>
          </author>

          <date month="March" year="1997" />

          <area>General</area>

          <keyword>keyword</keyword>

          <abstract>
            <t>In many standards track documents several words are used to
            signify the requirements in the specification. These words are
            often capitalized. This document defines these words as they
            should be interpreted in IETF documents. Authors who follow these
            guidelines should incorporate this phrase near the beginning of
            their document: <list>
                <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 RFC 2119.</t>
              </list></t>

            <t>Note that the force of these words is modified by the
            requirement level of the document in which they are used.</t>
          </abstract>
        </front>
      </reference>

      <reference anchor="RFC3611">
        <front>
          <title>RTP Control Protocol Extended Reports (RTCP XR)</title>

          <author fullname="T. Friedman" initials="T." surname="Friedman">
            <organization></organization>
          </author>

          <author fullname="R. Caceres" initials="R." surname="Caceres">
            <organization></organization>
          </author>

          <author fullname="A. Clark" initials="A." surname="Clark">
            <organization></organization>
          </author>

          <date month="November" year="2003" />

          <abstract>
            <t>This document defines the Extended Report (XR) packet type for
            the RTP Control Protocol (RTCP), and defines how the use of XR
            packets can be signaled by an application if it employs the
            Session Description Protocol (SDP). XR packets are composed of
            report blocks, and seven block types are defined here. The purpose
            of the extended reporting format is to convey information that
            supplements the six statistics that are contained in the report
            blocks used by RTCP's Sender Report (SR) and Receiver Report (RR)
            packets. Some applications, such as multicast inference of network
            characteristics (MINC) or voice over IP (VoIP) monitoring, require
            other and more detailed statistics. In addition to the block types
            defined here, additional block types may be defined in the future
            by adhering to the framework that this document provides.</t>
          </abstract>
        </front>
      </reference>

      <reference anchor="RFC4566">
        <front>
          <title>SDP: Session Description Protocol</title>

          <author fullname="M. Handley" initials="M." surname="Handley">
            <organization></organization>
          </author>

          <author fullname="V. Jacobson" initials="V." surname="Jacobson">
            <organization></organization>
          </author>

          <author fullname="C. Perkins" initials="C." surname="Perkins">
            <organization></organization>
          </author>

          <date month="July" year="2006" />

          <abstract>
            <t>This memo defines the Session Description Protocol (SDP). SDP
            is intended for describing multimedia sessions for the purposes of
            session announcement, session invitation, and other forms of
            multimedia session initiation. [STANDARDS-TRACK]</t>
          </abstract>
        </front>
      </reference>

      <reference anchor="RFC3550">
        <front>
          <title>RTP: A Transport Protocol for Real-Time Applications</title>

          <author fullname="Henning Schulzrinne" initials="H."
                  surname="Schulzrinne">
            <organization>Columbia University</organization>
          </author>

          <date month="July" year="2003" />
        </front>

        <seriesInfo name="RFC" value="3550" />

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

      <reference anchor="RFC6709">
        <front>
          <title>Design Considerations for Protocol Extensions</title>

          <author fullname="B.Carpenter" initials="B." surname="Carpenter">
            <organization></organization>
          </author>

          <author fullname="B.Aboba" initials="B." surname="Aboba">
            <organization></organization>
          </author>

          <author fullname="S.Cheshire" initials="S." surname="Cheshire">
            <organization></organization>
          </author>

          <date month="September" year="2012" />
        </front>

        <seriesInfo name="RFC" value="6709" />

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

    <references title="Informative References">
      <reference anchor="RFC6792">
        <front>
          <title>Monitoring Architectures for RTP</title>

          <author fullname="Geoff Hunt" initials="G." surname="Hunt">
            <organization></organization>
          </author>

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

          <author fullname="Philip Arden" initials="P." surname="Arden">
            <organization></organization>
          </author>

          <date month="November" year="2012" />
        </front>

        <seriesInfo name="RFC" value="6792" />

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

      <reference anchor="RFC6390">
        <front>
          <title>Framework for Performance Metric Development</title>

          <author fullname="Alan Clark" initials="A." surname="Clark">
            <organization></organization>
          </author>

          <author fullname="Benoit Claise " initials="B." surname="Claise">
            <organization></organization>
          </author>

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

        <seriesInfo name="RFC" value="6390" />
      </reference>

      <reference anchor="RFC6776">
        <front>
          <title>Measurement Identity and information Reporting using SDES
          item and XR Block</title>

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

          <date month="August" year="2012" />
        </front>

        <seriesInfo name="RFC" value="6776" />

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

    <section title="Change Log">
      <t>Note to the RFC-Editor: please remove this section prior to
      publication as an RFC.</t>

      <section title="draft-ietf-xrblock-rtcp-xr-jb-02">
        <t>The following are the major changes to previous version : <list
            style="symbols">
            <t>Add some explaination text in the SDP offer/answer section.</t>

            <t>Add some text in applicability section to explain the use to
            report jitter buffer metrics.</t>

            <t>Other editorial change changes aligning with PDV,Delay
            draft.</t>
          </list></t>
      </section>

      <section title="draft-ietf-xrblock-rtcp-xr-jb-01">
        <t>The following are the major changes to previous version : <list
            style="symbols">
            <t>Outdated reference update</t>

            <t>Add one Editor notes to ask clarification on the use of
            reporting jitter buffer metrics.</t>

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

      <section title="draft-ietf-xrblock-rtcp-xr-jb-00">
        <t>The following are the major changes to previous version : <list
            style="symbols">
            <t>Boilerplate updates.</t>

            <t>references updates</t>

            <t>allocate 32 bit field in report block for SSRC</t>

            <t>Other editorial changes to get alignment with MONARCH
            draft.</t>
          </list></t>
      </section>
    </section>
  </back>
</rfc>