<?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-wu-xrblock-rtcp-xr-one-way-delay-02.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="One Way Delay">RTCP XR Report Block for One Way Delay
    metric Reporting</title>

    <author fullname="R.van Brandenburg" initials="R.van"
            surname="Brandenburg">
      <organization>TNO</organization>

      <address>
        <email>ray.vanbrandenburg@tno.nl</email>
      </address>
    </author>

    <author fullname="Kevin Gross" initials="K." surname="Gross">
      <organization>AVA Networks</organization>

      <address>
        <email>kevin.gross@avanw.com</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="Fernando Boronat Segu" initials="F." surname="Boronat">
      <organization abbrev="UPVLC">Universitat Politecnica de
      Valencia</organization>

      <address>
        <postal>
          <street>IGIC Institute, Campus de Gandia, C/ Paraninfo, 1, Grao de
          Gandia</street>

          <city>Valencia</city>

          <code>46730</code>

          <country>Spain</country>
        </postal>

        <email>fboronat@dcom.upv.es</email>
      </address>
    </author>

    <author fullname="M. Montagud" initials="M." surname="Montagud">
      <organization abbrev="UPVLC">Universitat Politecnica de
      Valencia</organization>

      <address>
        <postal>
          <street>IGIC Institute, Campus de Gandia, C/ Paraninfo, 1, Grao de
          Gandia</street>

          <city>Valencia</city>

          <code>46730</code>

          <country>Spain</country>
        </postal>

        <email>mamontor@posgrado.upv.es</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 RTCP XR Report Block that allows the
      reporting of One Way Delay metrics for use in a range of RTP
      applications.</t>
    </abstract>
  </front>

  <middle>
    <section anchor="intro" title="Introduction">
      <section title="Packet One Way Delay Metrics Block">
        <t><xref target="I-D.ietf-xrblock-rtcp-xr-delay"></xref> defines the
        new block type supporting the reporting of the mean, minimum and
        maximum values of the network round-trip delay between media
        source(source) and media receiver(destination). However none of these
        metrics allow a receiver to report one way delay from source to
        destination or the other way around. As described in <xref
        target="RFC2679"></xref>, the path from a source to a destination may
        be different than the path from the destination back to the source.
        Even when the two paths are symmetric, they may have radically
        different performance characteristics. Therefore the measurement of
        one-way delay can not be roughly estimated by the round-trip delay for
        many applications in the asymmetric network and even symmetric
        network.</t>

        <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.
        The new block type supports the reporting of the mean, minimum,
        maximum values of one way network delay between RTP interfaces in peer
        RTP end systems, as measured, for example, using the method described
        in <xref target="RFC2679"></xref>.</t>

        <t>This metrics belong to the class of transport metrics defined in
        <xref target="MONARCH"></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 draft defines a new Extended Report block. The use of Extended
        Report blocks is defined by <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="MONARCH"></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="MONARCH"></xref>.</t>
      </section>

      <section title="Applicability">
        <t>These metrics are applicable to a range of delay-sensitive RTP
        applications in which this report block would be useful, such as some
        IDMS use cases (e.g., video wall, network games, networked
        loudspeakers, etc., see Draft IDMS <xref target="IDMS"></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>
      </section>
    </section>

    <section title="One Way Delay Block">
      <t>Metrics in this block report on one way packet delay in the stream
      arriving at the RTP system.</t>

      <section title="Report Block Structure">
        <t>One Way Delay metrics block<figure
            title="Figure 1: Report Block Structure">
            <artwork>
      0               1               2               3
      0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |     BT=OWD    | I |  resv.    |      block length = 4         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                           SSRC of Source                      |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Median-One-way-Network-Delay               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Max-One-way-Network-Delay                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    Min-One-way-Network-Delay                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork>
          </figure></t>
      </section>

      <section title="Definition of Fields in One Way Delay Metrics Report Block">
        <t><list style="hanging">
            <t hangText="Block type (BT): 8 bits"><vspace blankLines="1" />A
            One way Delay Report Block is identified by the constant
            OWD.<vspace blankLines="1" />[Note to RFC Editor: please replace
            OWD 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 One
            Way Metrics are Sampled, Interval or Cumulative metrics <xref
            target="MONARCH"></xref>, that is, whether the reported values
            applies to the most recent measurement interval duration between
            successive metrics reports (I=10) (the Interval Duration), to the
            accumulation period characteristic of cumulative measurements
            (I=11) (the Cumulative Duration) or is a sampled instantaneous
            value (I=01). <vspace blankLines="1" /></t>

            <t hangText="Reserved (resv): 6 bits"><vspace
            blankLines="1" />These bits are reserved. They SHOULD be set to
            zero by senders and MUST be ignored by receivers.<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
            Delay block, the block length is equal to 4. <vspace
            blankLines="1" /></t>

            <t hangText="SSRC of source: 32 bits"><vspace blankLines="1" />The
            SSRC of the media source shall be set to the value of the SSRC
            identifier carried in the RTP header <xref
            target="RFC3550"></xref> of the RTP packet to which the XR
            relates. <vspace blankLines="1" /></t>

            <t hangText="Median-One-way-Network-Delay: 32 bits"><vspace
            blankLines="1" />The Mean One way Delay is the mean value of the
            RTP-to- RTP interface one way delay in units of 1/65536 seconds
            over the measurement period. It can be calculated using RTCP SR/RR
            or RTP media packet according to section 3.6 of <xref
            target="RFC2679"></xref>. For details on one way delay
            calculation, see <xref target="cal"></xref>. <vspace
            blankLines="1" /></t>

            <t hangText="Max-One-way-Network-Delay: 32 bits"><vspace
            blankLines="1" />The Max One Way Delay is the maximum value of the
            RTP- to-RTP interface one way delay in units of 1/65536 seconds
            over the measurement period. It can be calculated using RTCP SR/RR
            or RTP media packet according to section 3.6 of <xref
            target="RFC2679"></xref>. For details on one way delay
            calculation, see <xref target="cal"></xref>. <vspace
            blankLines="1" /></t>

            <t hangText="Min-One-way-Network-Delay: 32 bits"><vspace
            blankLines="1" />The Max One Way Delay is the minimum value of the
            RTP- to-RTP interface one way delay in units of 1/65536 seconds
            over the measurement period. It can be calculated using RTCP SR/RR
            or RTP media packet according to section 3.6 of <xref
            target="RFC2679"></xref>. For details on one way delay
            calculation, see <xref target="cal"></xref>. <vspace
            blankLines="1" /></t>
          </list></t>
      </section>
    </section>

    <section title="Clock synchronization for one way delay metrics">
      <t>This subsection provides informative guidance on use of methodology
      for one way delay metrics measurement.</t>

      <t>As specified in the methodology of <xref target="RFC2679"></xref>, it
      is important for media source (Src) and media receiver (Dst) to
      synchronize very closely since one way delay values will often be as low
      as the 100 usec to 10 msec range. In order to arrange Src and Des
      synchronized before measurement method is applied, a participant at the
      Dst can indicate which synchronization source is being used at the
      moment. A participant can also indicate any other synchronization
      sources available to it. This allows multiple participants in an RTP
      session to use the same or a similar clock synchronization source for
      their session.</t>
    </section>

    <section anchor="cal"
             title="One way delay calculation based on measurement method in RFC2679">
      <t>TBC.</t>
    </section>

    <section title="SDP Signaling">
      <t><xref target="RFC3611"></xref> 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>

      <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>
rtcp-xr-attrib = "a=" "rtcp-xr" ":" [xr-format *(SP xr-format)] CRLF

(defined in [RFC3611])

xr-format =/ xr-one-way-delay-block
   
xr-one-way-delay-block ="one way delay"
</artwork>
        </figure></t>
    </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 OWD in the IANA "RTCP XR
        Block Type Registry" to the "One Way Delay Metrics Block".</t>

        <t>[Note to RFC Editor: please replace OWD 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 "one way delay" 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>
  </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="RFC2679">
        <front>
          <title>A One-way Delay Metric for IPPM</title>

          <author fullname="G.,Almes" initials="G." surname="Almes">
            <organization></organization>
          </author>

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

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

          <date month="September" year="1999" />
        </front>

        <seriesInfo name="RFC" value="2679" />

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

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

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

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

        <seriesInfo name="ID" value="draft-ietf-avtcore-monarch-17" />

        <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="I-D.ietf-xrblock-rtcp-xr-delay">
        <front>
          <title>RTCP XR Report Block for Delay metric Reporting</title>

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

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

          <author fullname="K.Gross" initials="K." surname="Gross">
            <organization></organization>
          </author>

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

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

        <seriesInfo name="ID" value="draft-ietf-xrblock-rtcp-xr-delay-06" />

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

      <reference anchor="IDMS">
        <front>
          <title>RTCP for inter-destination media synchronization</title>

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

          <author fullname="H.Stokking" initials="H." surname="Stokking">
            <organization></organization>
          </author>

          <author fullname="M.van,Deventer" initials="M.van"
                  surname="Deventer">
            <organization></organization>
          </author>

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

        <seriesInfo name="ID" value="draft-ietf-avtcore-idms-05" />

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