Network Working Group
Internet Engineering Task Force (IETF)                          A. Clark
Internet-Draft
Request for Comments: 7266                                      Telchemy
Intended status:
Category: Standards Track                                          Q. Wu
Expires: August 31, 2014
ISSN: 2070-1721                                                   Huawei
                                                               R. Schott
                                                        Deutsche Telekom
                                                                 G. Zorn
                                                             Network Zen
                                                       February 27,
                                                               June 2014

            RTP Control Protocol (RTCP) Extended Report (XR)
          Blocks for MOS Mean Opinion Score (MOS) Metric Reporting
                   draft-ietf-xrblock-rtcp-xr-qoe-17

Abstract

   This document defines an RTP Control Protocol (RTCP) Extended Report
   (XR) Block including two new segment types and associated SDP Session
   Description Protocol (SDP) parameters that allow the reporting of
   mean opinion score (MOS) Metrics for use in a range of RTP
   applications.

Status of this This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   Internet-Drafts are draft documents valid the IETF community.  It has
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   This Internet-Draft will expire on August 31, 2014.
   http://www.rfc-editor.org/info/rfc7266.

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   document authors.  All rights reserved.

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Table of Contents

   1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4 ....................................................3
      1.1. MOS Metrics Report Block . . . . . . . . . . . . . . . . .  4 ...................................3
      1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . .  4 ...................................3
      1.3. Performance Metrics Framework  . . . . . . . . . . . . . .  4 ..............................3
      1.4. Applicability  . . . . . . . . . . . . . . . . . . . . . .  4 ..............................................3
   2. Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  5 .....................................................4
      2.1. Standards Language . . . . . . . . . . . . . . . . . . . .  5 .........................................4
   3.  MoS MOS Metrics Block  . . . . . . . . . . . . . . . . . . . . . .  5 ...............................................5
      3.1. Report Block Structure . . . . . . . . . . . . . . . . . .  6 .....................................6
      3.2. Definition of Fields in MoS MOS Metrics Block  . . . . . . . .  7 ..................6
           3.2.1.  Single Channel audio/video Single-Channel Audio/Video per SSRC Segment  . . . . .  8 .........7
           3.2.2. Multi-Channel audio Audio per SSRC Segment . . . . . . . . .  9 ................9
   4. SDP Signaling  . . . . . . . . . . . . . . . . . . . . . . . . 11 ..................................................10
      4.1. SDP rtcp-xr-attrib "rtcp-xr-attrib" Attribute Extension . . . . . . . . . . 11 ..................10
      4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 13 ........................................12
   5. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 15 ............................................14
      5.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 15 Value ..............................14
      5.2. New RTCP XR SDP Parameter  . . . . . . . . . . . . . . . . 15 .................................14
      5.3. The SDP calgextmap "calgextmap" Attribute . . . . . . . . . . . . . . . 15 ............................14
      5.4. New registry Registry of calculation algorithms . . . . . . . . . . 16 Calculation Algorithms ....................15
   6. Security Considerations  . . . . . . . . . . . . . . . . . . . 17 ........................................16
   7. Authors  . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 ........................................................16
   8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17 ...............................................17
   9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18 .....................................................17
      9.1. Normative References . . . . . . . . . . . . . . . . . . . 18 ......................................17
      9.2. Informative References . . . . . . . . . . . . . . . . . . 18 ....................................18
   Appendix A. Metrics represented using RFC6390 Represented Using the RFC 6390 Template  . . . . . 20
   Appendix B.  Change Log  . . . . . . . . . . . . . . . . . . . . . 23
     B.1.  draft-ietf-xrblock-rtcp-xr-qoe-15  . . . . . . . . . . . . 23
     B.2.  draft-ietf-xrblock-rtcp-xr-qoe-14  . . . . . . . . . . . . 23
     B.3.  draft-ietf-xrblock-rtcp-xr-qoe-10  . . . . . . . . . . . . 23
     B.4.  draft-ietf-xrblock-rtcp-xr-qoe-09  . . . . . . . . . . . . 23
     B.5.  draft-ietf-xrblock-rtcp-xr-qoe-08  . . . . . . . . . . . . 23
     B.6.  draft-ietf-xrblock-rtcp-xr-qoe-07  . . . . . . . . . . . . 24
     B.7.  draft-ietf-xrblock-rtcp-xr-qoe-06  . . . . . . . . . . . . 24
     B.8.  draft-ietf-xrblock-rtcp-xr-qoe-04  . . . . . . . . . . . . 24
     B.9.  draft-ietf-xrblock-rtcp-xr-qoe-03  . . . . . . . . . . . . 24
     B.10. draft-ietf-xrblock-rtcp-xr-qoe-02  . . . . . . . . . . . . 24
     B.11. draft-ietf-xrblock-rtcp-xr-qoe-01  . . . . . . . . . . . . 24
     B.12. draft-ietf-xrblock-rtcp-xr-qoe-00  . . . . . . . . . . . . 25
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 25 .......20

1.  Introduction

1.1.  MOS Metrics Report Block

   This document defines a new block type to augment those defined in
   [RFC3611], for use in a range of RTP applications.

   The new block type provides information on media quality using one of
   several standard metrics (i.e.  Mean Opinion Score(MOS)). (e.g., mean opinion score (MOS)).

   The metrics belong to the class of application level application-level metrics defined
   in [RFC6792].

1.2.  RTCP and RTCP XR Reports

   The use of RTCP for reporting is defined in [RFC3550].  RFC3611  RFC 3611
   defined an extensible structure for reporting using an RTCP Extended
   Report (XR).  This document defines a new Extended Report block for
   use with [RFC3550] and [RFC3611].

1.3.  Performance Metrics Framework

   The Performance Metrics Framework [RFC6390] provides guidance on the
   definition and specification of performance metrics.  The RTP
   Monitoring Architectures document [RFC6792] provides guidelines for
   reporting block format using RTCP XR.  The XR block type described in
   this document are is in accordance with the guidelines in [RFC6390] and
   [RFC6792].

1.4.  Applicability

   The MOS Metrics Report Block can be used in any application of RTP
   for which QoE (Quality of Experience) (Quality-of-Experience) measurement algorithms are
   defined.

   The factors that affect real-time audio/video application quality can
   be split into two categories.  The first category consists of
   transport-specific factors such as packet loss, delay delay, and jitter
   (which also translates into losses in the playback buffer).  The
   factors in the second category consists of content content- and codec related codec-related
   factors such as codec type and loss recovery technique, coding bit
   rate, packetization scheme, and content characteristics

   Transport-specific factors may be insufficient to infer real time real-time
   media quality as codec related parameters and the interaction between
   transport problems and application layer application-layer protocols can have a
   substantial effect on observed media quality.  Media quality may be
   measured using algorithm algorithms that directly compare input and output
   media streams, or it may be estimated using algorithms that model the
   interaction between media quality, protocol protocol, and encoded content.
   Media quality is commonly expressed in terms of Mean Opinion Score
   (MOS) however MOS; however, it is
   also represented by a range of indexes and other scores.

   The measurement of media quality has a number of applications:

   o  Detecting problems with media delivery or encoding that is
      impacting user perceived user-perceived quality.

   o  Tuning the content encoder algorithm to satisfy real time real-time data
      quality requirements.

   o  Determining which system techniques to use in a given situation
      and when to switch from one technique to another as system
      parameters change (for example example, as discussed in [P.1082]). [G.1082]).

   o  Pre-qualifying  Prequalifying a network to assess its ability to deliver an
      acceptable end-user perceived end-user-perceived quality level.

2.  Terminology

2.1.  Standards Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

   The

   Notable terminology used is the following.

      Numeric formats X:Y

         where X the number of bits prior to the decimal place and Y the
         number of bits after the decimal place.
         Hence

         Hence, 8:8 represents an unsigned number in the range 0.0 to
         255.996 with a granularity of 0.0039. 0:16 represents a proper
         binary fraction with range 0.0 to 1 - 1/65536 = 0.9999847 0.9999847,
         though note that use of flag values at the top of the numeric
         range slightly reduces this upper limit.  For example, if the
         16- bit
         16-bit values 0xfffe 0XFFFE and 0xffff 0XFFFF are used as flags for "over-
         range" and "unavailable" conditions, a 0:16 quantity has range
         0.0 to 1 - 3/65536 = 0.9999542 0.9999542.

      Calculation Algorithm

         Calculation Algorithm is used in this document to mean the MOS
         or QoE estimation algorithm.

3.  MoS  MOS Metrics Block

   Multimedia

   A multimedia application MOS Metric is commonly expressed as a MOS
   ("Mean Opinion Score"), MOS.
   The MOS is usually on a scale from 1 to 5, in which 5 represents
   excellent and 1 represents unacceptable however unacceptable; however, it can use other
   ranges (for example example, 0 to 10 ) . ).  The term "MOS score" "MOS" originates from
   subjective testing, testing and is used to refer to the Mean mean of a number of
   individual Opinion Scores.  There opinion scores.  Therefore, there is therefore a well
   understood well-understood
   relationship between MOS and user experience, hence experience; hence, the industry
   commonly uses MOS as the scale for objective test results.
   Subjective tests can be used for measuring live network traffic
   however traffic;
   however, the use of objective or algorithmic measurement techniques
   allows much larger scale measurements to be made.  Within the scope
   of this document, MOS mean opinion scores are obtained using objective or
   estimation algorithms.  ITU-T or ITU-R recommendations (e.g.,
   [BS.1387-1],[G.107],[G.107.1],[P.862],[P.862.1],[P.862.2],[P.863],[P.
   564],[G.1082],[P.1201.1],[P.1201.2],[P.1202.1],[P.1202.2])
   [BS.1387-1], [G.107], [G.107.1], [P.862], [P.862.1], [P.862.2],
   [P.863], [P.564], [G.1082], [P.1201.1], [P.1201.2], [P.1202.1],
   [P.1202.2]) define methodologies for assessment of the performance of
   audio and video streams.  Other international and national standards
   organizations such as EBU, ETSI, IEC IEC, and IEEE also define QoE
   algorithms and methodologies, and the intent of this document is not
   to restrict its use to ITU recommendations but to suggest that ITU
   recommendations be used where they are defined.

   This block reports the media quality in the form of a MOS range
   (e.g., 1-5, 0-10, or 0-100, as specified by the calculation
   algorithm) however
   algorithm); however, it does not report the MoS score MOS that include includes
   parameters outside the scope of the RTP stream, for example example,
   signaling performance, mean time to repair (MTTR) (MTTR), or other factors
   that may affect the overall user experience.

   The MOS Metric reported in this block gives a numerical indication of
   the perceived quality of the received media stream, which is
   typically measured at the receiving end of the RTP stream.  Instances
   of this Metrics Block refer by Synchronization synchronization source (SSRC) to the
   separate auxiliary Measurement Information block [RFC6776] which
   describes measurement periods in use (see RFC6776 section RFC 6776, Section 4.2).

   This Metrics Block relies on the measurement period in the
   Measurement Information block indicating the span of the report.
   Senders MUST send this block in the same compound RTCP packet as the
   measurement information
   Measurement Information block.  Receivers MUST verify that the
   measurement period is received in the same compound RTCP packet as
   this Metrics Block.  If not, this Metrics Block MUST be discarded.

3.1.  Report Block Structure

   The MOS Metrics Block has the following format:

       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=MMB     BT=29     | I |  Reserved |       Block Length            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        SSRC of source                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Segment  1                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Segment 2                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      ..................
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                          Segment n                            |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

3.2.  Definition of Fields in MoS MOS Metrics Block

   Block type (BT): 8 bits

      The MOS Metrics Block is identified by the constant <MMB>. 29.

   Interval Metric flag (I): 2 bits

      This field is used to indicate whether the MOS Metrics are
      Sampled, Interval Interval, or Cumulative [RFC6792]:

         I=10: Interval Duration - the reported value applies to the
               most recent measurement interval duration between
               successive metrics reports.

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

         I=01: Sampled Value - the reported value is a sampled
               instantaneous value.

         I=00: Reserved

      In this document, MOS Metrics MAY be reported for intervals or for
      the duration of the media stream (cumulative).  The value I=01,
      indicating a sampled value, MUST NOT be sent, sent and MUST be discarded
      when received.

   Reserved: 6 bits

      This field is reserved for future definition.  In the absence of
      such a definition, the bits in this field MUST be set to zero and
      ignored by the receiver (See RFC6709 section (see RFC 6709, Section 4.2).

   Block Length: 16 bits

      The length of this report block in 32-bit words, minus one.  For
      the MOS Metrics Block, the block length is variable length.

   SSRC of source: 32 bits

      As defined in Section 4.1 of [RFC3611].

   Segment i: 32 bits

      There are two segment types defined in this document: single
      stream Audio/Video single-
      channel audio/video per SSRC segment, segment and multi-channel audio per
      SSRC segment.  Multi-channel audio per SSRC segment is used to
      deal with the case where Multi-channel audios multi-channel audio streams are carried
      in one RTP stream while single channel Audio/Video a single-channel audio/video per SSRC
      segment is used to deal with the case where each media stream is
      identified by SSRC and sent in separate RTP stream. streams.  The leftmost
      bit of the segment determines its type.  If the leftmost bit of
      the segment is zero, then it is single channel a single-channel segment.  If the
      leftmost bit is one, then it is a multi-channel audio segment.
      Note that two segment types can not cannot be present in the same metric
      block.

3.2.1.  Single Channel audio/video  Single-Channel Audio/Video per SSRC Segment

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |S|     CAID      |    PT       |           MOS Value           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Segment Type (S): 1 bit

      This field is used to identify the segment type used in this
      report block.  A zero identifies this as a single channel Audio/
      Video single-channel
      audio/video per SSRC segment.  Single channel means there is only
      one media stream carried in one RTP stream.  The single channel Audio/
      Video single-channel
      audio/video per SSRC segment can be used to report the MOS value
      associated with the media stream identified by SSRC.  If there are
      multiple media streams and they want to use the single channel
      Audio/Video single-channel
      audio/video per SSRC segment to report the MOS value, they should
      be carried in the separate RTP streams with each identified by
      different SSRC.  In this case, multiple MOS Metrics Blocks are
      required to report the MOS value corresponding to each media
      stream using single channel Audio/Video single-channel audio/video per SSRC segment in the
      same RTCP XR packet.

   Calculation Algorithm ID (CAID) : 8 bits

      The 8-bit CAID is the session specific reference to the
      calculation algorithm and associated qualifiers indicated in SDP
      (see Section 4.1) and used to compute the MOS score for this
      segment.

   Payload Type (PT): 7 bits

      MOS Metrics reporting depends on the payload format in use.  This
      field identifies the RTP payload type in use during the reporting
      interval.  The binding between RTP payload types and RTP payload
      formats is configured via a signalling signaling protocol, for example example, an
      SDP offer/answer exchange.  If the RTP payload type used is
      changed during an RTP session, separate reports SHOULD be sent for
      each RTP payload type, with corresponding measurement information
      blocks indicating the time period to which they relate.

      Note that the use of this Report Block with MPEG Transport streams
      carried over RTP is undefined as each MPEG Transport stream may
      use distinct audio or video codecs and the indication of the
      encoding of these is within the MPEG Transport stream and does not
      use RTP payloads.

   MOS Value: 16 bits

      The estimated Mean Opinion Score mean opinion score (MOS) for multimedia application
      performance is defined as including estimated using an algorithm that includes the effects
      impact of delay, loss,
      discard, jitter and other effects impairments that would affect
      media quality.  This is a an unsigned fixed-point 7:9 value
      representing the MOS, allowing the MOS score up to 127 in the
      integer part.  MOS ranges are defined as part of the specification
      of the MOS estimation algorithm (Calculation Algorithm in this
      document), and are normally ranges like 1-5, 0-10, or 0-100.  Two
      values are reserved: A a value of 0xFFFE indicates that the
      measurement is out of range and a value of 0xFFFF indicates that
      the measurement is unavailable.  Values outside of the range
      defined by the Calculation Algorithm, other than the two reserved
      values, MUST NOT be sent and MUST be ignored by the receiving
      system.

3.2.2.  Multi-Channel audio Audio per SSRC Segment

   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |S|     CAID      |    PT       |CHID |        MOS Value        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Segment Type (S): 1 bit

      This field is used to identify the segment type used in this
      report block.  A one identifies this as a multi-channel audio
      segment.

   Calculation Algorithm ID (CAID) : 8 bits

      The 8-bit CAID is the session specific reference to the
      calculation algorithm and associated qualifiers indicated in SDP
      (see Section 4.1) and used to compute the MOS score for this
      segment.

   Payload Type (PT): 7 bits

      As defined in Section 3.2.1 of this document

   Channel Identifier (CHID): 3 bits

      If multiple channels of audio are carried in one RTP stream, each
      channel of audio will be viewed as a an independent channel(e.g., channel (e.g.,
      left channel audio, right channel audio).  This field is used to
      identify each channel carried in the same media stream.  The
      default Channel channel mapping follows static ordering rule described in
      the section
      Section 4.1 of [RFC3551].  However  However, there are some payload formats
      that use different channel mappings, e.g., AC-3 audio over RTP
      [RFC4184] only follow AC-3 channel order scheme defined in [ATSC].
      Enhanced AC-3 Audio audio over RTP [RFC4598] uses a dynamic channel
      transform mechanism.  In order that for the appropriate channel mapping can
      to be determined, MOS metrics reports need to be tied to an RTP
      payload format, i.e., including format.  The reports should include the payload type of
      the reported media according to [RFC6792] and using Payload Type [RFC6792], so that it can be used
      to determine the appropriate channel mapping.

   MOS Value: 13 bits

      The estimated Mean Opinion Score (MOS) MOS for multimedia application performance is
      defined as including the effects of delay, loss, discard, jitter
      and other effects that would affect media quality.  This is a an
      unsigned fixed-point 7:6 value representing the MOS, allowing the
      MOS score up to 127 in the integer part.  MOS ranges are defined
      as part of the specification of the MOS estimation algorithm
      (Calculation Algorithm in this document), and are normally ranges
      like 1-5, 0-10, or 0-100.  Two values are reserved: A a value of
      0x1FFE indicates out of range and a value of 0x1FFF indicates that
      the measurement is unavailable.  Values outside of the range
      defined by the Calculation Algorithm, other than the two reserved
      values, MUST NOT be sent and MUST be ignored by the receiving
      system.

4.  SDP Signaling

   [RFC3611]defines

   [RFC3611] defines the use of SDP (Session Description Protocol) [RFC4566] for signaling the use of
   XR blocks.  However  However, XR blocks MAY be used without prior signaling
   (see section Section 5 of RFC3611). RFC 3611).

4.1.  SDP rtcp-xr-attrib "rtcp-xr-attrib" Attribute Extension

   This section augments the SDP [RFC4566] attribute "rtcp-xr" defined
   in [RFC3611] by providing an additional value of "xr-format" to
   signal the use of the report block defined in this document.  Within
   the "xr-format", the syntax element "calgextmap" is an attribute as
   defined in [RFC4566] and used to signal the mapping of the local
   identifier (CAID) in the segment extension defined in section Section 3.2 to
   the calculation algorithm.  Specific extensionattributes extension attributes are defined
   by the specification that defines a specific extension name; name: there
   might be several.  The ABNF [RFC5234] syntax is as follows.

   xr-format =/ xr-mos-block
   xr-mos-block = "mos-metric" ["=" calgextmap *("," calgextmap)]
   calgextmap =  mapentry "=" extensionname [SP extentionattributes]
   direction = "sendonly" / "recvonly" / "sendrecv" / "inactive"
   mapentry = "calg:" 1*3 DIGIT ["/" direction] 1*3DIGIT [ "/" direction ]
                          ; Values in the range 1-255 are valid
                          ; if needed, 0 can be used to indicate that
                          ; an algorithm is rejected
   extensionname = "P564";ITU-T P.564 Compliant Algorithm [P.564]
                 / "G107";ITU-T G.107 [G.107]
                 / "G107_1";ITU-T G.107.1 [G.107.1]
                 / "TS101_329";ETSI TS 101 329-5 Annex E [ ETSI]
                 /"JJ201_1 ";TTC JJ201.1 [TTC]
                 /"P1201_1";ITU-T P.1201.2 [P.1201.1]
                 /"P1201_2";ITU-T P.1201.2 [P.1201.2]
                 /"P1202_1";ITU-T P.1202.1 [P.1202.1]
                 /"P1202_2";ITU-T P.1202.2 [P.1202.2]
                 /"P.862.2";ITU-T P.862.2 [P.862.2]
                 /"P.863"; ITU-T P.863 [P.863]
                 / non-ws-string
   extensionattributes = mosref
                       /attributes-ext
   mosref =  "mosref=" ("l"; lower resolution
                        /"m"; middle resolution
                        / "h";higher resolution
                       / non-ws-string)
   attributes-ext = non-ws-string
   SP = <Define <Defined in RFC5234> RFC 5234>
   non-ws-string  = 1*(%x21-FF)

   Each local identifier (CAID)of (CAID) of calculation algorithm used in the
   segment defined in the section Section 3.2 is mapped to a string using an
   attribute of the form:

   a=calg:<value> ["/"<direction>] [ "/"<direction> ] <name> [<extensionattributes>]

   where <name> is a calculation algorithm name, as above, <value> is
   the local identifier (CAID)of (CAID) of the calculation algorithm associated
   with the segment defined in this document and is an integer in the
   valid range range, inclusive.

   Example:
   a=rtcp-xr:mos-metric=calg:1=G107,calg:2=P1202_1

   A usable mapping MUST use IDs in the valid range, and each ID in this
   range MUST be unique and used only once for each stream or each
   channel in the stream.

   The mapping MUST be provided per media stream (in the media-level
   section(s) of SDP, i.e., after an "m=" line).

   The syntax element "mosref" is referred to the media resolution
   relative reference and has three valules 'l','m','h'.(e.g.,
   Narrowband (3.4kHz) Speech values 'l','m','h'. (e.g.,
   narrowband (3.4 kHz) speech and Standard Definition (SD) or lower
   Resolution Video
   resolution video have 'l' resolution, Super Wideband (>14kHz) Speech super-wideband (>14 kHz) speech
   or higher and High Definition (HD) or higher Resolution Video resolution video have
   'h' Resolution, Wideband speech(7khz) resolution, wideband speech (7 kHz) and Video video with resolution
   between SD and HD has 'm' resolution).  The MOS score reported in the MOS
   metrics block might vary with the MOS reference; For for example, MOS
   values for narrowband, wideband, super wideband super-wideband codecs occupy the
   same range but SHOULD be reported in different value.  For video
   application, MOS scores for SD resolution, HD resolution video also
   occupy the same ranges and SHOULD be reported in different value.

4.2.  Offer/Answer Usage

   When SDP is used in offer-answer offer/answer context, the SDP Offer/Answer usage
   defined in [RFC3611] applies.  In the offer answer offer/answer context, the
   signaling described above might be used in three ways:

   o  asymmetric behavior (segment extensions sent in only one
      direction),

   o  the offer of mutually exclusive alternatives, or

   o  the offer of more segments than can be sent in a single session.

   A direction attribute MAY be included in a calgextmap; "calgextmap"; without it,
   the direction implicitly inherits, of course, from the RTCP stream
   direction.

   Segment extensions, with their directions, MAY be signaled for an
   "inactive" stream.  An extension direction MUST be compatible with
   the stream direction.  If a segment extension in the SDP offer is
   marked as "sendonly" and the answerer desires to receive it, the
   extension MUST be marked as "recvonly" in the SDP answer.  An
   answerer that has no desire to receive the extension or does not
   understand the extension SHOULD NOT include it in the SDP answer.

   If a segment extension is marked as "recvonly" in the SDP offer and
   the answerer desires to send it, the extension MUST be marked as
   "sendonly" in the SDP answer.  An answerer that has no desire to, or
   is unable to, send the extension SHOULD NOT include it in the SDP
   answer.

   If a segment extension is offered as "sendrecv", explicitly or
   implicitly, and asymmetric behavior is desired, the SDP MAY be
   modified to modify or add direction qualifiers for that segment
   extension.

   A mosref "mosref" attribute and MOS type "MOS Type" attribute MAY be included in an a
   calgextmap; without it, if not present, the mosref "mosref" and most type attribute implicitly
   inherits, of course, from "MOS Type" MUST be as
   defined in the QoE estimation algorithm referenced by the name
   attribute (e.g., P.1201.1 [P.1201.1] indicates lower resolution used
   while P.1201.2 [P.1201.2] indicates higher resolution used) or
   payload type carried in the segment extension (e.g.,EVRC-WB (e.g., EVRC-WB
   [RFC5188] indicates using Wideband Codec).  However  However, not all payload
   types or MOS algorithm names indicate resolution to be used and MOS
   type to be used.  If an answerer receives an offer with an mosref a "mosref"
   attribute value it doesn't support (e.g.,the answerer only supports
   "l" and receives "h"from "h" from offerer), the answer SHOULD reject the
   mosref attribute value offered by the offerer.

   If the answerer wishes to reject a mosref "mosref" attribute offered by the
   offerer, it sets identifiers associated with segment extensions in
   the answer to the value in the range 4096-4351.  The rejected answer
   MUST contain 'mosref ' a "mosref" attribute whose value is the value of the SDP
   offer.

   Local identifiers in the valid range inclusive (inclusive) in an offer or
   answer must not be used more than once per media section.  A session
   update MAY change the direction qualifiers of segment extensions
   under use.  A session update MAY add or remove segment extension(s).  Identifiers
   Identifier values in the valid range MUST NOT be altered (remapped).

   If a party wishes to offer mutually exclusive alternatives, then
   multiple segment extensions with the same identifier in the
   (unusable) range 4096-4351 MAY be offered; the answerer SHOULD select
   at most one of the offered extensions with the same identifier, and
   remap it to a free identifier in the valid range, range for that extension
   to be usable.  Note that the two segment types defined in section Section 3
   are also two exclusive alternatives.

   If more segment extensions are offered in the valid range, the
   answerer SHOULD choose those that are desired, desired and place the offered
   identifier value "as is" in the SDP answer.

   Similarly, if more segment extensions are offered than can be fit in
   the valid range, identifiers in the range 4096-4351 MAY be offered;
   the answerer SHOULD choose those that are desired, desired and remap them to a
   free identifier in the valid range.

   Note that the range 4096-4351 for these negotiation identifiers is
   deliberately restricted to allow expansion of the range of valid
   identifiers in the future.  Segment extensions with an identifier
   outside the valid range cannot, of course, be used.

   Example (port

   Example:

   Note - port numbers, RTP profiles, payload IDs and rtpmaps, etc. etc.,
   have all been omitted for brevity): brevity.

   The offer:

   a=rtcp-xr:mos-metric=calg:4906=P1201_l,calg:4906=P1202_l, calg:
   4907=G107

   The answerer is interested in transmission P.1202.1 on a lower
   resolution application, but it doesn't support P.1201.1 on a lower
   resolution application at all.  It is interested in transmission
   G.107.  It therefore  Therefore, it adjusts the declarations:

   a=rtcp-xr:mos-metric=calg:1=P1202_l,calg:2=G107

5.  IANA Considerations

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

5.1.  New RTCP XR Block Type value Value

   This document assigns the block type value MMB 29 in the IANA " RTP "RTP
   Control Protocol Extended Reports (RTCP XR) Block Type Registry" to
   the "MOS Metrics Block".

   [Note to RFC Editor: please replace MMB with the IANA provided RTCP
   XR block type for this block.]

5.2.  New RTCP XR SDP Parameter

   This document also registers a new parameter "mos-metric" in the "
   RTP "RTP
   Control Protocol Extended Reports (RTCP XR) Session Description
   Protocol (SDP) Parameters Registry".

5.3.  The SDP calgextmap "calgextmap" Attribute

   This section contains the information required by [RFC4566] for an
   SDP attribute.

   o  contact name, email address: RAI Area Directors
      <rai-ads@tools.ietf.org>
   o  attribute name (as it will appear in SDP): calgextmap

   o  long-form attribute name in English: calculation algorithm map
      definition

   o  type of attribute (session level, media level, or both): both

   o  whether the attribute value is subject to the charset attribute:
      not subject to the charset attribute

   o  a one-paragraph explanation of the purpose of the attribute: This
      attribute defines the mapping from the local identifier (CAID) in
      the segment extension defined in section Section 3.2 into the calculation
      algorithm name as documented in specifications and appropriately
      registered.

   o  a specification of appropriate attribute values for this
      attribute: see RFC xxxx. 7266.

5.4.  New registry Registry of calculation algorithms Calculation Algorithms

   This document creates a new registry to be called "RTCP XR MOS Metric block
   - multimedia application Calculation Algorithm" as a sub-
   registry subregistry of
   the "RTP Control Protocol Extended Reports (RTCP XR) Block Type
   Registry".  This registry applies to the multimedia session where
   each type of media are medium is sent in a separate RTP stream and also applies
   to the session where Multi-channel multi-channel audios are carried in one RTP
   stream.  Policies for this new registry are as follows:

   o  The information required to support this assignment is an
      unambiguous definition of the new metric, covering the base
      measurements and how they are processed to generate the reported
      metric.

   o  The review process for the registry is "Specification Required" as
      described in Section 4.1 of [RFC5226].

   o  Entries in the registry are identified by entry name and mapped to
      the local identifier (CAID) in the segment extension defined in
      section
      Section 3.2.

   o  Registration Template

      The following information must be provided with each registration:

      *  Name: A string uniquely and unambiguously identifying the
         Calculation
         calculation algorithm for use in protocols.

      *  Name Description: A valid Description of the Calculation calculation
         algorithm name. Name.

      *  Reference: The reference which that defines the calculation algorithm
         corresponding to the Name and Name Description.

      *  Type: The media type to which the calculation algorithm is
         applied

   o  Initial assignments are as follows:

   Name       Name Description                  Reference     Type
   =========   ===================================  ================================  ==========    ====
   P564       ITU-T P.564 Compliant Algorithm   [P.564]        Voice       voice
   G107       ITU-T G.107                       [G.107]        Voice       voice
   TS101_329  ETSI TS 101 329-5 Annex E         [ETSI]         Voice        voice
   JJ201_1    TTC JJ201.1                       [TTC]          Voice         voice
   G107_1     ITU-T G.107.1                     [G.107.1]      Voice     voice
   P862       ITU-T P.862                       [P.862]        Voice       voice
   P862_2     ITU-T P.862.2                     [P.862.2]      Voice     voice
   P863       ITU-T P.863                       [P.863]        Voice       voice
   P1201_1    ITU-T P.1201.1                    [P.1201.1]      Multimedia    multimedia
   P1201_2    ITU-T P.1201.2                    [P.1201.2]      Multimedia    multimedia
   P1202_1    ITU-T P.1202.1                    [P.1202.1]         Video    video
   P1202_2    ITU-T P.1202.2                    [P.1202.2]         Video    video

6.  Security Considerations

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

7.  Authors

   This draft document merges ideas from two drafts documents addressing the MOS
   Metric Reporting issue.  The authors of these drafts documents are listed
   below (in alphabetical order):

      Alan Clark < alan.d.clark@telchemy.com > <alan.d.clark@telchemy.com>
      Geoff Hunt < r.geoff.hunt@gmail.com > <r.geoff.hunt@gmail.com>
      Martin Kastner < martin.kastner@telchemy.com >
      Qin Wu < sunseawq@huawei.com > <martin.kastner@telchemy.com>
      Kai Lee <leekai@ctbri.com.cn>
      Roland Schott < roland.schott@telekom.de > <roland.schott@telekom.de>
      Qin Wu <sunseawq@huawei.com>
      Glen Zorn < gwz@net-zen.net >
      Kai Lee < leekai@ctbri.com.cn > <gwz@net-zen.net>

8.  Acknowledgements

   The authors gratefully acknowledge the comments and contributions
   made 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, Bill Ver Steeg, David R R.
   Oran, Ted Lemon,Benoit Lemon, Benoit Claise, Pete Resnick, Ali Begen Begen, and Hideaki
   Yamada.

9.  References

9.1.  Normative References

   [ATSC]     U.S.       Advanced Television Systems Committee (ATSC), "ATSC
              Standard: Digital Committee, Inc., "Digital
                Audio Compression (AC-3), Standard (AC-3, E-AC-3) Revision B",
                ATSC Doc Document A/52B, June 2005.

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

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

   [RFC3551]    Schulzrinne, H. and S. Casner, "RTP Profile for Audio
                and Video Conferences with Minimal Control", STD 65, RFC
                3551, July 2003.

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

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

   [RFC5226]    Narten, T., T. and H. Alvestrand, "Guidelines for Writing an
                IANA Considerations Section in RFCs", BCP 26, RFC 5226,
                May 2008.

   [RFC5234]    Crocker, D. D., Ed., and P. Overell, "Augmented BNF for
                Syntax Specifications: ABNF", STD 68, RFC 5234, January
                2008.

   [RFC6776]    Clark, A. and Q. Wu, Q., "Measurement Identity and information
                Information Reporting
              using SDES item Using a Source Description (SDES)
                Item and XR an RTCP Extended Report (XR) Block", RFC 6776,
                October 2012.

9.2.  Informative References

   [BS.1387-1]  ITU-R, "Method for objective measurements of perceived
                audio quality", ITU-R Recommendation BS.1387-1, 2001.
                1998-2001.

   [ETSI]       ETSI, "Quality "TIPHON Release 3; Technology Compliance
                Specification; Part 5: Quality of Service (QoS)
                measurement methodologies", ETSI TS 101 329-5 V1.1.1,
                November 2000.

   [G.107]      ITU-T, "The E Model, a computational model for use in
                transmission planning", ITU-T Recommendation G.107,
              April 2009.
                February 2014.

   [G.107.1]    ITU-T, "Wideband E-model", ITU-T Recommendation G.107.1,
                December 2011.

   [G.1082]     ITU-T, "Measurement-based methods for improving the
                robustness of IPTV performance", ITU-T Recommendation
                G.1082, April 2009.

   [P.1201.1]   ITU-T, "Parametric non-intrusive assessment of
                audiovisual media streaming quality - lower Lower resolution
                application area", ITU-T Recommendation P.1201.1,
                October 2012.

   [P.1201.2]   ITU-T, "Parametric non-intrusive assessment of
                audiovisual media streaming quality - higher Higher resolution
                application area", ITU-T Recommendation P.1201.2,
                October 2012.

   [P.1202.1]   ITU-T, "Parametric non-intrusive bitstream assessment of
                video media streaming quality - lower Lower resolution
                application area", ITU-T Recommendation P.1202.1,
                October 2012.

   [P.1202.2]   ITU-T, "Parametric non-intrusive bitstream assessment of
                video media streaming quality - higher Higher resolution
                application area", ITU-T Recommendation P.1202.2, May
                2013.

   [P.564]      ITU-T, "Conformance testing for narrowband Voice over IP
                transmission quality assessment models", ITU-T
                Recommendation P.564, July 2006. November 2007.

   [P.862]      ITU-T, "Perceptual evaluation of speech quality (PESQ):
                An objective method for end-to-end speech quality
                assessment of narrow-band telephone networks and speech
                codecs", ITU-T Recommendation P.862, Febuary February 2001.

   [P.862.1]    ITU-T, "Mapping function for transforming P.862 raw
                result scores to MOS-LQO", ITU-T Recommendation P.862.1,
                November 2003.

   [P.862.2]    ITU-T, "Wideband extension to Recommendation P.862 for
                the assessment of wideband telephone networks and speech
                codecs", ITU-T Recommendation P.862.2, November 2007.

   [P.863]      ITU-T, "Perceptual objective listening quality
                assessment", ITU-T Recommendation P.863, January 2011.

   [RFC4184]    Link, B., Hager, T., and J. Flaks, "RTP Payload Format
                for AC-3 Audio", RFC 4184, October 2005.

   [RFC4598]    Link, B., "Real-time Transport Protocol (RTP) Payload
                Format for Enhanced AC-3 (E-AC-3) Audio", RFC 4598, July
                2006.

   [RFC5188]    Desineni, H. and Q. Xie, "RTP Payload Format for the
                Enhanced Variable Rate Wideband Codec (EVRC-WB) and the
                Media Subtype Updates for EVRC-B Codec", RFC 5188,
                February 2008.

   [RFC6390]    Clark, A. and B. Claise, "Framework "Guidelines for Considering New
                Performance Metric Development", BCP 170, RFC 6390,
                October 2011.

   [RFC6792]    Wu, Q., "Monitoring Architectures Ed., Hunt, G., and P. Arden, "Guidelines for RTP", Use
                of the RTP Monitoring Framework", RFC 6792, November
                2012.

   [TTC]      TTC 201.01 (Japan),        Telecommunication Technology Committee, "A method Method for speech quality
              assessment
                Speech Quality Assessment for Voice over IP". IP Telephony", TTC
                JJ-201.01 (Japan), November 2013,
                <http://www.ttc.or.jp/jp/document_list/pdf/j/STD/
                JJ-201.01v7.pdf>.

Appendix A.  Metrics represented using RFC6390 Template

   RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by Represented Using the new Template from RFC
   number, when assigned. 6390

   a.  MOS Value Metric

      *  Metric Name: MOS in RTP

      *  Metric Description: The estimated Mean Opinion Score mean opinion score for
         multimedia application performance of the RTP stream is defined
         as including the effects of delay,loss, discard,jitter delay, loss, discard, jitter, and other
          effects that would affect
         others on audio or video quality.

      *  Method of Measurement or Calculation: See section Section 3.2.1, MOS
         value definition [RFCXXXX]. definition.

      *  Units of Measurement: See section Section 3.2.1, MOS value definition
          [RFCXXXX]. definition.

      *  Measurement Point(s) with Potential Measurement Domain: See
          section
         Section 3, 2nd paragraph [RFCXXXX]. second paragraph.

      *  Measurement Timing: See section Section 3, 3rd third paragraph [RFCXXXX] for
         measurement timing and section Section 3.1 [RFCXXXX] for Interval Metric flag.

      *  Use and applications: See section 1.4 [RFCXXXX]. Section 1.4.

      *  Reporting model: See RFC3611. RFC 3611.

   b.  Segment Type Metric

      *  Metric Name: Segment Type in RTP

      *  Metric Description: It is used to identify the segment type of
         RTP stream used in this report block.  For more details, see
          section
         Section 3.2.1, Segment type definition.

      *  Method of Measurement or Calculation: See section Section 3.2.1,
         Segment Type definition [RFCXXXX]. definition.

      *  Units of Measurement: See section Section 3.2.1, Segment Type
          definition [RFCXXXX].
         definition.

      *  Measurement Point(s) with Potential Measurement Domain: See
          section
         Section 3, 2nd paragraph [RFCXXXX]. second paragraph.

      *  Measurement Timing: See section Section 3, 3rd third paragraph [RFCXXXX] for
         measurement timing and section Section 3.1 [RFCXXXX] for Interval Metric flag.

      *  Use and applications: See section 1.4 [RFCXXXX]. Section 1.4.

      *  Reporting model: See RFC3611. RFC 3611.

   c.  Calculation Algorithm Identifier Metric

      *  Metric Name: RTP Stream Calculation Algorithm Identifier

      *  Metric Description: It is the local identifier of RTP Stream
         calculation Algorithm associated with this segment in the range
         1-255 inclusive. (inclusive).

      *  Method of Measurement or Calculation: See section Section 3.2.1,
         Calculation Algorithm ID definition [RFCXXXX]. definition.

      *  Units of Measurement: See section Section 3.2.1, Calg Algorithm ID
          definition[RFCXXXX].
         definition.

      *  Measurement Point(s) with Potential Measurement Domain: See
          section
         Section 3, 2nd paragraph [RFCXXXX]. second paragraph.

      *  Measurement Timing: See section Section 3, 3rd third paragraph [RFCXXXX] for
         measurement timing and section Section 3.1 [RFCXXXX] for Interval Metric flag.

      *  Use and applications: See section 1.4 [RFCXXXX]. Section 1.4.

      *  Reporting model: See RFC3611. RFC 3611.

   d.  Payload Type Metric

      *  Metric Name: RTP Payload Type

      *  Metric Description: It is used to identify the format of the
         RTP payload.  For more details, see section Section 3.2.1, payload type
         definition.

      *  Method of Measurement or Calculation: See section Section 3.2.1,
         Payload type definition [RFCXXXX]. definition.

      *  Units of Measurement: See section Section 3.2.1, payload Payload type
          definition[RFCXXXX].
         definition.

      *  Measurement Point(s) with Potential Measurement Domain: See
          section
         Section 3, 2nd paragraph [RFCXXXX]. second paragraph.

      *  Measurement Timing: See section Section 3, 3rd third paragraph [RFCXXXX] for
         measurement timing and section Section 3.1 [RFCXXXX] for Interval Metric flag.

      *  Use and applications: See section 1.4 [RFCXXXX]. Section 1.4.

      *  Reporting model: See RFC3611. RFC 3611.

   e.  Channel Identifier Metric

      *  Metric Name: Audio Channel Identifier in RTP

      *  Metric Description: It is used to identify each audio channel
         carried in the same RTP stream.  For more details, see section Section
         3.2.2, channel identifier definition.

      *  Method of Measurement or Calculation: See section Section 3.2.2,
         Channel Identifier definition [RFCXXXX]. definition.

      *  Units of Measurement: See section Section 3.2.2, channel identifier
          definition[RFCXXXX]. Channel Identifier
         definition.

      *  Measurement Point(s) with Potential Measurement Domain: See
          section
         Section 3, 2nd paragraph [RFCXXXX]. second paragraph.

      *  Measurement Timing: See section Section 3, 3rd third paragraph [RFCXXXX] for
         measurement timing and section Section 3.1 [RFCXXXX] for Interval Metric flag.

      *  Use and applications: See section 1.4 [RFCXXXX]. Section 1.4.

      *  Reporting model: See RFC3611.

Appendix B.  Change Log

B.1.  draft-ietf-xrblock-rtcp-xr-qoe-15

   The following are the major changes compared to previous version:
   o  Some Editorial Changes.

B.2.  draft-ietf-xrblock-rtcp-xr-qoe-14

   The following are the major changes compared to previous version:
   o  Add some texts to address IESG review comments.

B.3.  draft-ietf-xrblock-rtcp-xr-qoe-10

   The following are the major changes compared to previous version:
   o  Replace QoE metrics with MoS metrics.

B.4.  draft-ietf-xrblock-rtcp-xr-qoe-09

   The following are the major changes compared to previous version:
   o  Address comments recieved from WGLC, PM-DIR Review and SDP review.
   o  Change an existing SDP attribute 'extmap' to new SDP attribute
      'calgextmap' and add new SDP attribute registry.
   o  Add Reference to G.107.1, P.862.1, P.862.2 and P.863 for new
      calculation algorithms.
   o  Add MoS type attribute to distinguish different MoS type.
   o  Other Editorial changes.

B.5.  draft-ietf-xrblock-rtcp-xr-qoe-08

   The following are the major changes compared to previous version:

   o  Remove mostype attribute from SDP extension since it can inferred
      from payload type.
   o  Clarify mosref attribute usage in the O/A.

B.6.  draft-ietf-xrblock-rtcp-xr-qoe-07

   The following are the major changes compared to previous version:
   o  Some editorial changes to get in line with burst gap related
      draft.
   o  Add an appendix to apply RFC6390 template.

B.7.  draft-ietf-xrblock-rtcp-xr-qoe-06

   The following are the major changes compared to previous two
   versions:
   o  A few Contact information update.
   o  A few Acknowledgement section update.

B.8.  draft-ietf-xrblock-rtcp-xr-qoe-04

   The following are the major changes compared to previous version:
   o  Split two references P.NAMS and P.NBAMS into four references.
   o  SDP signaling update.
   o  Add one example to explain User QoE evaluation for video stream

B.9.  draft-ietf-xrblock-rtcp-xr-qoe-03

   The following are the major changes compared to previous version:
   o  Add one new reference to support TTC JJ201.01.
   o  Update two references P.NAMS and P.NBAMS.
   o  Other Editorial changes based on comments applied to PDV and Delay
      drafts.

B.10.  draft-ietf-xrblock-rtcp-xr-qoe-02

   The following are the major changes compared to previous version:
   o  Remove leftmost second bit since it is ueeless.
   o  Change 13bits MoS value field into 14 bits to increase MoS
      precision.
   o  Fix some typo and make some editorial changes.

B.11.  draft-ietf-xrblock-rtcp-xr-qoe-01

   The following are the major changes compared to previous version:
   o  Remove layered support from the QoE Metric draft.
   o  Allocate 7 bits in the block header for payload type to indicate
      what type of payload format is in use and add associated
      definition of payload type.

   o  Clarify using Payload Type to determine the appropriate channel
      mapping in the definition of Channel Identifier.

B.12.  draft-ietf-xrblock-rtcp-xr-qoe-00

   The following are the major changes compared to previous version:
   o  Allocate one more bit in the single channel per SSC segment to get
      alignment with the other two segment type. RFC 3611.

Authors' Addresses

   Alan Clark
   Telchemy Incorporated
   2905 Premiere Parkway, Suite 280
   Duluth, GA  30097
   USA

   Email:

   EMail: alan.d.clark@telchemy.com

   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email:

   EMail: sunseawq@huawei.com

   Roland Schott
   Deutsche Telekom
   Heinrich-Hertz-Strasse 3-7
   Darmstadt  64295
   Germany

   Email:

   EMail: Roland.Schott@telekom.de

   Glen Zorn
   Network Zen
   77/440 Soi Phoomjit, Rama IV Road
   Phra Khanong, Khlong Toie
   Bangkok  10110
   Thailand

   Phone: +66 (0) 87 502 4274
   Email:
   EMail: gwz@net-zen.net