One document matched: draft-ietf-xrblock-rtcp-xr-burst-gap-discard-10.xml


<?xml version="1.0" encoding="UTF-8"?>
<!-- edited with XMLSPY v5 rel. 3 U (http://www.xmlspy.com)
     by Daniel M Kohn (private) -->
<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
<!ENTITY rfc2119 PUBLIC "" "http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml">
]>
<rfc category="std"
     docName="draft-ietf-xrblock-rtcp-xr-burst-gap-discard-10.txt"
     ipr="trust200902">
  <?xml-stylesheet type='text/xsl' href='rfc2629.xslt' ?>

  <?rfc toc="yes" ?>

  <?rfc symrefs="yes" ?>

  <?rfc sortrefs="yes"?>

  <?rfc iprnotified="no" ?>

  <?rfc strict="yes" ?>

  <front>
    <title abbrev="RTCP XR Burst/Gap Discard">RTP Control Protocol(RTCP)
    Extended Report (XR) Block for Burst/Gap Discard 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="Rachel Huang" initials="R" surname="Huang">
      <organization abbrev="Huawei">Huawei Technologies Co.,
      Ltd.</organization>

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

          <city>Nanjing</city>

          <region>Jiangsu</region>

          <code>210012</code>

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

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

    <author fullname="Qin Wu" initials="Q." role="editor" 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="2013" />

    <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 Burst and Gap Discard metrics
      for use in a range of RTP applications.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <section title="Burst and Gap Discard Report 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.
        The new block type supports the reporting of the proportion of packets
        discarded by the receiver due to jitter. The discards during discard
        bursts are reported, together with the number of bursts. This block is
        intended to be used in conjunction with <xref target="DISCARD"></xref>
        which provides the total packets discarded, and on which this block
        therefore depends. However the metric in <xref
        target="DISCARD"></xref> may be used independently of the metrics in
        this block.</t>

        <t>This block provides information on transient IP problems. Burst/Gap
        metrics are typically used in Cumulative reports, however they also
        MAY be used in Interval reports. The burstiness of packet discard
        affects user experience, may influence any sender strategies to
        mitigate the problem, and may also have diagnostic value.</t>

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

        <t>The definitions of Burst, Gap, Loss and Discard are consistent with
        definitions in <xref target="RFC3611"></xref>. To accommodate the
        range of jitter buffer algorithms and packet discard logic that may be
        used by implementors, the method used to distinguish between bursts
        and gaps may be an equivalent method to that defined in<xref
        target="RFC3611"></xref>.</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. The Metrics Block described in this document are in
        accordance with the guidelines in <xref target="RFC6390"></xref> and
        <xref target="RFC6792"></xref>.</t>
      </section>

      <section title="Applicability">
        <t>These metrics are applicable to a range of RTP applications which
        contain jitter buffers and don't use stream repair means,e.g., Forward
        Error Correction (FEC) <xref target="RFC5109"></xref> and/or
        retransmission <xref target="RFC4588"></xref>.</t>
      </section>
    </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="Received, Lost and Discarded"><vspace
            blankLines="1" />A packet shall be regarded as lost if it fails to
            arrive within an implementation-specific time window. A packet
            that arrives within this time window but is too early or late to
            be played out or thrown away before playout due to packet
            duplication or redundancy shall be regarded as discarded. A packet
            shall be classified as one of received (or OK), discarded or lost.
            The metric "cumulative number of packets lost" defined in <xref
            target="RFC3550"></xref> reports a count of packets lost from the
            media stream (single SSRC within single RTP session). Similarly
            the metric "number of packets discarded" defined in <xref
            target="DISCARD"></xref> reports a count of packets discarded from
            the media stream (single SSRC within single RTP session) arriving
            at the receiver. Another metric defined in <xref
            target="RFC5725"></xref> is available to report on packets which
            are not recovered by any repair techniques which may be in use.
            <vspace blankLines="1" /></t>

            <t hangText="Bursts and Gaps"><vspace blankLines="1" />The terms
            Burst and Gap are used in a manner consistent with that of RTCP XR
            [RFC3611]. RTCP XR views a RTP stream as being divided into
            bursts, which are periods during which the discard rate is high
            enough to cause noticeable quality degradation (generally over 5
            percent discard rate), and gaps, which are periods during which
            discarded packets are infrequent and hence quality is generally
            acceptable. <vspace blankLines="1" /></t>
          </list></t>
      </section>
    </section>

    <section title="Burst/Gap Discard Block">
      <t>Metrics in this block report on Burst/Gap Discard in the stream
      arriving at the RTP system. The measurement of these metrics are made at
      the receiving end of the RTP stream. Instances of this Metrics Block
      refer by Synchronization source (SSRC) to the separate auxiliary
      Measurement Information block <xref target="RFC6776"></xref> which
      describes measurement periods in use (see RFC6776 section 4.2). This
      Metrics Block relies on the measurement period 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 period is not received in the same compound RTCP
      packet as this Metrics Block, this Metrics Block MUST be discarded.</t>

      <section title="Report Block Structure">
        <t>Burst/Gap Discard 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=NBGD    | I |   resv.   |      block length = 3         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        SSRC of Source                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |   Threshold   |         Packets Discarded in Bursts           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |       Total Packets expected in bursts        |   Reserved.   | 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
          </figure></t>
      </section>

      <section title="Definition of Fields in Burst/Gap Discard Report Block">
        <t><list style="hanging">
            <t hangText="Block type (BT): 8 bits"><vspace blankLines="1" />A
            Burst/Gap Discard Report Block is identified by the constant
            NBGD.<vspace blankLines="1" />[Note to RFC Editor: please replace
            NBGD 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
            Burst/Gap Discard 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>In this document, Burst/Gap Discard Metrics can only be
            measured over definite intervals, and cannot be sampled.
            Accordingly, the value I=01, indicating a sampled value, MUST NOT
            be used. In addition, the value I=00 is reserved and also MUST NOT
            be used. The block MUST be discarded if the value I=01 or I=00 is
            received. <vspace blankLines="1" /></t>

            <t hangText="Reserved (resv): 6 bits"><vspace
            blankLines="1" />These bits are reserved. They MUST be set to zero
            by senders and 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. For the
            Burst/Gap discard block, the block length is equal to 3. The block
            MUST be discarded if the block length is set to a different
            value.<vspace blankLines="1" /></t>

            <t hangText="SSRC of source: 32 bits"><vspace blankLines="1" />As
            defined in Section 4.1 of <xref target="RFC3611"></xref>.<vspace
            blankLines="1" /></t>

            <t hangText="Threshold: 8 bits"><vspace blankLines="1" />The
            Threshold is equivalent to Gmin in <xref target="RFC3611"></xref>,
            i.e. the number of successive packets that must not be discarded
            prior to and following a discard packet in order for this
            discarded packet to be regarded as part of a gap. <vspace
            blankLines="1" /></t>

            <t hangText="Packets discarded in bursts: 24 bits"><vspace
            blankLines="1" />The total number of packets discarded during
            discard bursts.<vspace blankLines="1" />If the measured value
            exceeds 0xFFFFFD, the value 0xFFFFFE MUST be reported to indicate
            an over-range measurement. If the measurement is unavailable, the
            value 0xFFFFFF MUST be reported. <vspace blankLines="1" /></t>

            <t hangText="Total packets expected in bursts: 24 bits"><vspace
            blankLines="1" />The total number of packets expected during
            discarded bursts (that is, the sum of received packets and lost
            packets). <vspace blankLines="1" />If the measured value exceeds
            0xFFFFFD, the value 0xFFFFFE MUST be reported to indicate an
            over-range measurement. If the measurement is unavailable, the
            value 0xFFFFFF MUST be reported. <vspace blankLines="1" /></t>

            <t hangText="Reserved (resv): 8 bits"><vspace
            blankLines="1" />These bits are reserved. They MUST be set to zero
            by senders and ignored by receivers (See RFC6709 section 4.2).
            <vspace blankLines="1" /></t>
          </list></t>
      </section>

      <section title="Derived metrics based on reported metrics">
        <t>The metrics described here are intended to be used in conjunction
        with information from the Measurement Information block <xref
        target="RFC6776"></xref> (which MUST be present in the same RTCP
        packet as the Burst/Gap Discard block) and also with the metric
        "number of packets discarded" provided in the RTCP XR Discard Count
        Block <xref target="DISCARD"></xref>. The RTCP XR Discard Count Block
        SHOULD be sent if the Burst/Gap Discard block is sent, but the
        converse does not apply.</t>

        <t>These metrics provide the following information relevant to
        statistical parameters, including:<list style="symbols">
            <t>The fraction of packets discarded during bursts (burst discard
            rate in <xref target="SUMSTAT"></xref>), which can be calculated
            using the metric " Packets Discarded in Bursts " and the metric "
            Total Packets expected in Bursts " provided in the Burst/Gap
            Discard metrics block.</t>

            <t>The fraction of packets discarded during gaps (gap discard rate
            in <xref target="SUMSTAT"></xref>), which can be calculated using
            the metric " Packets Discarded in Bursts " and the metric " Total
            Packets expected in Bursts " provided in the Burst/Gap Discard
            metrics block.</t>
          </list></t>

        <t>The details on calculation these parameters in the metrics are
        described in <xref target="SUMSTAT"></xref>.</t>
      </section>
    </section>

    <section title="Considerations for Voice-over-IP applications">
      <t>This Metrics Block is applicable to a broad range of RTP
      applications. Where the metric is used with a Voice-overIP (VoIP)
      application and the stream repair means is not available, the following
      considerations apply.</t>

      <t>RTCP XR views a call as being divided into bursts, which are periods
      during which the discard rate is high enough to cause noticeable call
      quality degradation (generally over 5 percent discard rate), and gaps,
      which are periods during which discarded packets are infrequent and
      hence call quality is generally acceptable.</t>

      <t>If Voice Activity Detection is used the Burst and Gap Duration shall
      be determined as if silence packets had been sent, i.e. a period of
      silence in excess of Gmin packets MUST terminate a burst condition.</t>

      <t>The recommended value for the threshold Gmin in <xref
      target="RFC3611"></xref> results in a Burst being a period of time
      during which the call quality is degraded to a similar extent to a
      typical Pulse-Code Modulation(PCM) Severely Errored Second.</t>
    </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-bgd-block

xr-bgd-block = "brst-gap-dscrd"
</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 NBGD in the IANA " RTP
        Control Protocol Extended Reports (RTCP XR) Block Type Registry " to
        the "Burst/Gap Discard Metrics Block".</t>

        <t>[Note to RFC Editor: please replace NBGD 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 "brst-gap-dscrd" in
        the "RTP Control Protocol Extended Reports (RTCP XR) Session
        Description Protocol (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, Hideaki Yamada, Paul Kyzivat,Claire Bi and Dan
      Romascanu.</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="RFC5725">
        <front>
          <title>Post-Repair Loss RLE Report Block Type for RTP Control
          Protocol (RTCP) Extended Reports (XRs)</title>

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

          <author fullname="Dong Hsu" initials="D." surname="Hsu">
            <organization></organization>
          </author>

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

          <date month="February" year="2020" />
        </front>

        <seriesInfo name="RFC" value="5725" />

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

    <references title="Informative References">
      <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>

      <reference anchor="DISCARD">
        <front>
          <title>RTCP XR Report Block for Discard Count metric
          Reporting</title>

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

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

        <seriesInfo name="ID" value="draft-ietf-xrblock-rtcp-xr-discard-11" />

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

      <reference anchor="SUMSTAT">
        <front>
          <title>RTCP XR for Summary Statistics Metrics Reporting</title>

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

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

        <seriesInfo name="ID"
                    value="draft-ietf-xrblock-rtcp-xr-summary-stat-05" />

        <format type="TXT" />
      </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="October" year="2012" />
        </front>

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

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

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

          <author fullname="Geoff Hunt" initials="G." surname="Hunt">
            <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="RFC5109">
        <front>
          <title>RTP Payload Format for Generic Forward Error
          Correction</title>

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

          <date month="December" year="2007" />
        </front>

        <seriesInfo name="RFC" value="5109" />
      </reference>

      <reference anchor="RFC4588">
        <front>
          <title>RTP Retransmission Payload Format</title>

          <author fullname="J.,Rey" initials="J." surname="Rey">
            <organization></organization>
          </author>

          <author fullname="D.,Leon" initials="D." surname="Leon">
            <organization></organization>
          </author>

          <author fullname="A.,Miyazaki" initials="A.">
            <organization></organization>
          </author>

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

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

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

        <seriesInfo name="RFC" value="4588" />
      </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-burst-gap-discard-10">
        <t>The following are the major changes compared to previous
        version:<list style="symbols">
            <t>Move RFC6709 as one informative reference.</t>
          </list></t>
      </section>

      <section title="draft-ietf-xrblock-rtcp-xr-burst-gap-discard-09">
        <t>The following are the major changes compared to previous
        version:<list style="symbols">
            <t>Editorial changes based on comments received in WGLC.</t>
          </list></t>
      </section>

      <section title="draft-ietf-xrblock-rtcp-xr-burst-gap-discard-08">
        <t>The following are the major changes compared to previous
        version:<list style="symbols">
            <t>SDP update based on SDP Directorate Review.</t>

            <t>Add some texts to get consistent with RFC6798 and Delay
            draft.</t>
          </list></t>
      </section>

      <section title="draft-ietf-xrblock-rtcp-xr-burst-gap-discard-06">
        <t>The following are the major changes compared to previous
        version:<list style="symbols">
            <t>Outdated reference update.</t>

            <t>Editorial changes based on comments that applied to PDV and
            Delay drafts.</t>
          </list></t>
      </section>
    </section>
  </back>
</rfc>

PAFTECH AB 2003-20262026-04-23 22:30:57