One document matched: draft-wu-avt-rtcp-xr-quality-monitoring-01.xml


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<rfc category="std" docName="draft-wu-avt-rtcp-xr-quality-monitoring-01" ipr="trust200902">
	<front>
		<title abbrev="RTCP XR Video Quality Report Blocks">RTP Control Protocol Extended Reports (RTCP XR) Report Blocks for Real-time Video Quality Monitoring</title>

		<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="Glen Zorn" initials="G." surname="Zorn">
			<organization>Network Zen</organization>
			<address>
				<postal>
					<street>77/440 Soi Phoomjit, Rama IV Road</street>
					<street>Phra Khanong, Khlong Toie</street>
					<city>Bangkok</city>
					<code>10110</code>
					<country>Thailand</country>
				</postal>
				<phone>+66 (0) 87 502 4274</phone>
				<email>gwz@net-zen.net</email>
			</address>
		</author>

		<date year="2010" />

		<abstract>
			<t>
				This document defines a set of RTP Control Protocol Extended Reports (RTCP XR) Report Blocks and associated SDP parameters allowing the
				report of video quality metrics, primarily for video applications of RTP.
			</t>
		</abstract>
	</front>

	<middle>
		<section title="Introduction">
			<t>
				Along with the wide deployment of broadband access and the development of
				new IPTV services (e.g., broadcast video, video on demand),
				there is increasing interest in monitoring and managing networks and
				applications that deliver real-time applications over IP, to ensure that all
				end users obtain acceptable video/audio quality. The main drives come
				from operators, since offering performance monitoring capability can
				help diagnose network impairments, facilitate in root cause
				analysis and aid in verifying compliance with service level agreements (SLAs) between
				Internet Service Providers (ISPs) and content providers.
				<vspace blankLines="1"/>
				The factors that affect real-time application quality can be
				split into two categories. The first category consists of network-dependent
				factors such as packet loss, delay and jitter (which also
				translates into losses in the playback buffer). The factors in the
				second category are application-specific factors that affect video
				quality and its sensitivity to network errors. These factors can be but
				not limited to video codec and loss recovery technique, coding bit rate,
				packetization scheme, and content characteristics. 
				<vspace blankLines="1"/>
				Compared with application-specific factors, the network-dependent
				factors sometimes are not sufficient to measure video quality, since the
				ability to analyze the video in the application layer provides
				quantifiable measurements for subscriber Quality of Experience (QoE) that may not be captured in
				the transmission layers or from the RTP layer down. In a typical
				scenario, monitoring of the transmission layers can produce statistics suggesting
				that quality is not an issue, such as the fact that network jitter is
				not excessive. 
				However, problems may occur in the service layers leading
				to poor subscriber QoE. Therefore monitoring using only network-level
				measurements may be insufficient when application layer video quality is
				required.
				<vspace blankLines="1"/>
				In order to provide accurate measures of video quality for operators
				when transporting video across a network, conveying video quality metrics in RTCP XR packets
				<xref target="RFC3611"/>
				has the following three benefits:
				<list>
					<t>
						<list style="symbols">
							<t>
								Tuning the video encoder algorithm to satisfy video quality requirements
							</t>
							<t>
								Determining which system techniques to use in a given situation
								and when to switch from one technique to another as system
								parameters change
							</t>
							<t>
								Verifying the continued correct operation of an existing system
							</t>
						</list>
					</t>
				</list>
				<vspace blankLines="1"/>
				<xref target="RFC3611">RFC 3611</xref> defines seven report block
				formats for network management and quality monitoring.
				However, there are no block types specifically designed for conveying video quality
				metrics. This document focuses on specifying new report block types used
				to convey video-specific quality metrics.
				<vspace blankLines="1"/>
				The report block types defined in this document fall into two
				categories. The first category consists of synchronization information
				on received RTP packets. The report blocks in the second category convey
				metrics relating to packet receipts defined in <xref target="RFC3611">RFC 3611</xref>
				that are summary in nature but include data that is more
				detailed, or of a different type, than that conveyed in existing RTCP
				packets.
				<vspace blankLines="1"/>				
				Six report block formats are defined by this document. Of
				these, two are synchronization information blocks:
				<list>
					<t>
						<list style="symbols">
							<t>RTP Flows Synchronization Delay Report Block</t>
							<t>Audio-Video Synchronization Report Block</t>
						</list>
					</t>
				</list>
				<vspace blankLines="1"/>
				The other four are summary metrics blocks: 
				<list>
					<t>
						<list style="symbols">
							<t>Statistics Summary Report Block</t>
							<t>TR 101 290 Decodability Metrics Block <xref target="ETSI"/></t>
							<t>Video Stream Metrics Report Block</t>
							<t>Perceptual Quality Metrics Block</t>
						</list>
					</t>
				</list>
			</t>
		</section>

		<section title="Terminology">
			<section title="Standards Language">
				<t>
					The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
					"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
					document are to be interpreted as described in <xref target="RFC2119">RFC 2119</xref>.
				</t>
			</section>
			<section title="Acronyms">
				<t>
					<list style="hanging">
						<t hangText="SSRC">
							<vspace blankLines="0"/>
							<xref target="RFC3550">Synchronization Source</xref>
							<vspace blankLines="1"/>
						</t>
						<t hangText="TS">
							<vspace blankLines="0"/>
							<xref target="ISO-IEC.13818-1.2007">Transport Stream</xref>
						</t>
					</list>
				</t>
			</section>
		</section>

		<section title="Applicability">
			<t>
				All the report blocks defined in this document could be used by
				dedicated network monitoring applications. As specified in 
				<xref	target="RFC3611">RFC 3611</xref>, for such an application it might be
				appropriate to allow more than 5% of RTP data bandwidth to be used for
				RTCP packets, thus allowing proportionately larger and more detailed
				report blocks. 
				<vspace blankLines="1"/>
				The Audio-Video Synchronization Report Block <xref target="AVS"/>
				has been defined for video
				conferencing applications.  Such applications can use this report
				block to monitor A/V component synchronization to ensure satisfactory
				QoE. 
				Tighter tolerances than typically used have been recommended for such
				applications.
				<vspace blankLines="1"/>
				The Flows Synchronization Delay Report Block has been defined
				primarily for layered or multi-description video coding applications. 
				When joining a layered video session in such an application, a receiver may
				not synchronize playout across the multimedia session until RTCP SR
				packets have been received on all of the component RTP sessions. This
				report block can be used to ensure synchronization between different
				media layers for the same multimedia session.
				<vspace blankLines="1"/>
				The Stream Metrics Report Block and Statistics Summary Report Block
				can be applied to any real time video application, while the TR 101 290
				Decodability Metrics Report Block and Perceptual Quality Metrics Report
				Block can be used in any real-time AV application
				<xref	target="ETSI"></xref>.
			</t>
		</section>

		<section anchor="RFSD" title="RTP Flows Synchronization Delay Report Block">
			<t>
				This block reports synchronization delay between RTP sessions of the
				same video stream sent using Multi-Session Transmission <xref target="I-D.ietf-avt-rtp-svc"></xref>
				beyond the
				information carried in the standard RTCP packet format. Information is
				recorded about session bandwidth and synchronization delay.
				<vspace blankLines="1"/>
				The RTP Flows Synchronization Delay Report Block has the following format:
				
<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |   Reserved    |          Block length         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      SSRC of Sender                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     Session Bandwidth                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|               Initial Synchronization Delay                   |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

				<list style="hanging">
					<t hangText="Block type (BT): 8 bits">
						<vspace blankLines="0" />
						The Statistics Summary Report Block is identified by the constant <RFSD>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Reserved: 8 bits">
						<vspace blankLines="0" />
						This field is reserved for future definition. In the absence of such a
						definition, the bits in this field MUST be set to zero and MUST be
						ignored by the receiver.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Block length: 16 bits">
						<vspace blankLines="0" />
						The constant 3, in accordance with the definition of this field in
						Section 3 of <xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="SSRC of Sender: 32 bits">
						<vspace blankLines="0" />The
						SSRC of the RTP data packet source being reported upon by this
						report block. (<xref target="RFC3611">Section 4.1 of</xref>).
						<vspace blankLines="1"/>
					</t>
					<t hangText="Session Bandwidth: 32 bits">
						<vspace blankLines="0" />
						This field indicates the maximum bandwidth
						allocated to each RTP Session. The value in this field represents
						the bandwidth allocation per RTP Session in kilobits per second,
						with values in the range 0 <= BW < 65536.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Initial Synchronization Delay: 32 bits">
						<vspace blankLines="0" />
						The average delay, expressed in units of 1/65536
						seconds, between the RTCP packets received on all of the components
						RTP sessions and the beginning of session 
						<xref target="I-D.ietf-avt-rapid-rtp-sync"></xref>. 
						The value is calculated as follows:
						<vspace blankLines="1"/>
						<list>
							<t>
								Initial Synchronization Delay = max((the time interval
								between receiving the first RTP packet with synchronization
								metadata and the start of a session), (the time interval between
								receiving the first RTCP packet in the RTP session with the
								longest RTCP reporting interval and the start of a session)).
							</t>
						</list>
					</t>
				</list>
			</t>
		</section>

		<section anchor="AVS" title="Audio-Video Synchronization Report Block">
			<t>
				This block reports the audio-video synchronization requirements
				between audio and video components beyond the information carried in the
				standard RTCP packet format. Information is recorded about tolerant
				audio lead video time and tolerant audio lag video time.
				The Audio-Video Synchronization Report Block has the following format:
<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |L|  Reserved   |         Block length          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        SSRC of source                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Audio Lead Video       |       Audio Lag Video         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

			<list style="hanging">
				<t hangText="Block type (BT): 8 bits">
					<vspace blankLines="0"/>
					The Statistics Summary Report Block is identified by the constant <AVS>.
					<vspace blankLines="1"/>
				</t>
				<t hangText="Audio Lead/Lag Video flag (L): 1 bit">
					<vspace blankLines="0" />
					Bit set to 1 if Audio Lead Video field contains a
					report, 0 if Audio Lag Video field contains a report.
					<vspace blankLines="1"/>
				</t>
				<t hangText="Reserved: 7 bits">
					<vspace blankLines="0"/>
					This field is reserved for future definition. In the absence of such a
					definition, the bits in this field MUST be set to zero and MUST be
					ignored by the receiver.
					<vspace blankLines="1"/>
				</t>
				<t hangText="Block length: 16 bits">
					<vspace blankLines="0"/>
					The constant 2, in accordance with the definition of this field in
					Section 3 of <xref target="RFC3611">RFC 3611</xref>.
					<vspace blankLines="1"/>
				</t>
				<t hangText="SSRC of source: 32 bits">
					<vspace blankLines="0" />
					As defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
					<vspace blankLines="1"/>
				</t>
				<t hangText="Audio Lead Video time: 16 bits">
					<vspace blankLines="0"/>
						This field indicates the tolerant audio lead video
						time in milliseconds <xref target="DSLF"/>. This value is
						calculated based on the interarrival time between previous video RTP
						packet and the next first audio RTP packet and timestamps of both
						previous video RTP packet and the next first audio packet.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Audio Lag Video time: 16 bits">
						<vspace blankLines="0"/> 
						This field indicates the tolerant audio lag video
						time in milliseconds <xref target="DSLF"></xref>. This value is
						calculated based on the interarrival time between previous video RTP
						packet and the next first audio RTP packet and timestamps of both
						previous video RTP packet and the next first audio packet.
					</t>
				</list>
			</t>
		</section>

		<section anchor="VSS" title="Video Statistics Summary Report Block">
			<t>
				This block reports statistics beyond the information carried in the
				Statistics Summary Report Block RTCP packet specified in the section 4.6
				of <xref target="RFC3611">RFC 3611</xref>. Information is recorded about lost
				frame packets, duplicated frame packets, lost layered component packets,
				duplicated layered component packets. Such information can be useful for
				network management and video quality monitoring.
				<vspace blankLines="1"/>
				The report block contents are dependent upon a series of flag bits
				carried in the first part of the header. Not all parameters need to be
				reported in each block. Flags indicate which parameters are reported and
				which are not. The fields corresponding to unreported parameters MUST be
				present, but are set to zero. The receiver MUST ignore any Video Statistics Summary Report
				Block with a non-zero value in any field flagged as unreported.
				<vspace blankLines="1"/>
				The Video Statistics Summary Report Block has the following format:
<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |L|D|FT |  LT |P|        block length           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        SSRC of source                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          begin_seq            |             end_seq           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                         lost_frames                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                          dup frames                           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                 lost_layered component packets                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  dup layered component_packets                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                    lost_partial frame packets                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                     dup partial frame_packets                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

				<list style="hanging">
					<t hangText="Block type (BT): 8 bits">
						<vspace blankLines="0" />
						The Video Statistics Summary Report Block is identified by the constant <VSS>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="loss report flag (L): 1 bit">
						<vspace blankLines="0" />
						Bit set to 1 if the lost_frame packets field, the
						lost_layered_component field or the lost partial frame packets field
						contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="duplicate report flag (D): 1 bit">
						<vspace blankLines="0" />
						Bit set to 1 of the dup_frame packets field, the
						dup_layered_component packets field or the dup partial frame packets field
						contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Frame type indicator (FT): 2 bits">
						<vspace blankLines="0" />
						This field is used to indicate the frame type to be
						reported. Bits set to 01 if the lost_frames field or dup_frames field
						contain a I_frame report, 10 if the lost_frames field and dup_frames
						field contain a P frame report, 11 if the lost_frames field and
						dup_frames field contain a B frame report, 00 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Layer Type indicator (LT): 3 bits">
						<vspace blankLines="0" />
						This field is used to indicate the layer type of
						layered video to be reported. LT is set to 001 if the
						loss_component_packet field and dup_component packet contain the
						base layer packet in SVC <xref target="I-D.ietf-avt-rtp-svc"/>, 010 if the
						loss_component packet field and dup_component packet contain
						enhancement layer 1 packet in SVC, 011 if the loss_component packet
						field and dup_component packet contain the enhancement layer 2
						packet, 000 otherwise. 
						<vspace blankLines="1"/>
					</t>
					<t hangText="P: 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the lost_partial frame packets field or the dup_partial_frame packets field
						contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Block length: 16 bits">
						<vspace blankLines="0"/>
						The constant 8, in accordance with the definition of this field in Section 3 of 
						<xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="SSRC of source: 32 bits ">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="begin_seq: 16 bits ">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="end_seq: 16 bits ">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="lost_frames: 32 bits">
						<vspace blankLines="0"/>
						Number of lost_frames in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="dup_frames: 32 bits">
						<vspace blankLines="0"/>
						Number of dup_frames in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="lost_layered component packets: 32 bits">
						<vspace blankLines="0"/>
						Number of lost_component packets in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="dup_layered component packets: 32 bits">
						<vspace blankLines="0"/>
						Number of dup_component packets in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="lost_partial frame packets: 32 bits">
						<vspace blankLines="0"/>
						Number of lost_partial frame packets in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="dup_partial frame packets: 32 bits">
						<vspace blankLines="0"/>
						Number of dup_partial frame packets in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
				</list>
			</t>
		</section>

		<section anchor="TDM" title="TR 101 290 Decodability Metrics Report Block">
			<t>
				This block reports decodability metrics statistics beyond the
				information carried in the standard RTCP packet format. Information is
				recorded about the number of Transport Stream Synchronization Losses,
				Sync byte errors, Continuity count errors, Transport errors, Program Clock Reference (PCR) errors,
				PCR repetition errors, PCR discontinuity
				indicator errors, and Presentation Time Stamp (PTS) errors <xref target="ETSI"/>. 
				Such information can be useful for network
				management and video quality monitoring.
				<vspace blankLines="1"/>
				Note that this is only applicable to MPEG-2 RTP streams <xref target="RFC2250"/>.
				and not
				to any other video codec.
				<vspace blankLines="1"/>
				The report block contents are dependent upon a series of flag bits
				carried in the first part of the header. Not all parameters need to be
				reported in each block. Flags indicate which are and which are not
				reported. The fields corresponding to unreported parameters MUST be
				present, but are set to zero. The receiver MUST ignore any Decodability
				Metrics Block with a non-zero value in any field flagged as
				unreported.
				<vspace blankLines="1"/>
				The Decodability Metrics Block has the following format:

<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |L|B|C|T|P|S|rvd|         block length          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        SSRC of source                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          begin_seq            |             end_seq           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|       Number of packets       |         Number of TSs         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|             Transport Stream Synchronization Losses           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Sync byte errors                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                  Continuity count errors                      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                      Transport errors                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                         PCR errors                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                   PCR repetition errors                       |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|            PCR discontinuity indicator errors                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                         PTS errors                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

				<list style="hanging">
					<t hangText="block type (BT): 8 bits">
						<vspace blankLines="0"/>
						A TR 101 290 decodability metrics report block is identified by the constant <TDM>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Transport Stream Synchronization Loss flag (L): 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the Transport Stream Synchronization Loss field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Sync byte error flag (B): 1 bit">
						<vspace blankLines="0" />
							Bit set to 1 if the Sync byte error field contains a report, 0 otherwise.
							<vspace blankLines="1"/>
					</t>
					<t hangText="Continuity count error flag (C): 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the Continuity count error field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Transport error flag (T): 1 bit ">
						<vspace blankLines="0"/>
						Bit set to 1 if the Transport error field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PCR related error flag (P): 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the PCR error field, PCR repetition error field and PCR discontinuity indicator 
						error fields contain a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PTS error flag (S): 1 bit ">
						<vspace blankLines="0"/>
						Bit set to 1 if the PTS error field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="rvd: 2 bits">
						<vspace blankLines="0"/>
						This field is
						reserved for future definition. In the absence of such a definition,
						the bits in this field MUST be set to zero and MUST be ignored by
						the receiver.
						<vspace blankLines="1"/>
					</t>
					<t hangText="block length: 16 bits">
						<vspace blankLines="0"/>
						The constant 10, in accordance with the definition of this field in Section 3 of 
						<xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="SSRC of source: 32 bits">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611"></xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="begin_seq: 16 bits">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611"></xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="end_seq: 16 bits">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611"></xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Number of Packets: 16 bits">
						<vspace blankLines="0"/>
						Number of RTP packets in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Number of TSs: 16 bits">
						<vspace blankLines="0"/>
						Number of Transport Streams in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Transport Stream Synchronization Losses: 32 bits">
						<vspace blankLines="0"/>
						Number of Transport Stream Synchronization Losses
						in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Sync byte errors: 32 bits">
						<vspace blankLines="0"/>
						Number of Transport sync byte errors in the above sequence number interval.
					</t>
					<t hangText="Continuity count error: 32 bits">
						<vspace blankLines="0"/>
						Number of Transport Continuity count errors in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Transport errors: 32 bits">
						<vspace blankLines="0" />
						Number of Transport errors in the above sequence
						number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PCR errors: 32 bits ">
						<vspace blankLines="0"/>
						Number of PCR errors in the above
						sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PCR repetition errors: 32 bits">
						<vspace blankLines="0"/>
						Number of Transport PCR repetition errors in the
						above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PCR discontinuity indicator errors: 32 bits">
						<vspace blankLines="0"/>
						Number of PCR discontinuity indicator errors in the
						above sequence number interval.
						<vspace blankLines="1"/>
					</t>
					<t hangText="PTS errors: 32 bits">
						<vspace blankLines="0"/>
						Number of PTS errors in the above sequence number interval.
						<vspace blankLines="1"/>
					</t>
				</list>
			</t>
		</section>

		<section anchor="VSM" title="Video Stream Metrics Report Block">
			<t>
				The Video Stream Metrics Report Block provides metrics for monitoring
				the quality of video stream. This metrics includes Loss and discard
				metrics, Burst metrics, Delay metrics for I-Frame packets, B-Frame
				packets and P-Frame packets, Configuration parameter metrics. The block
				reports separately on packets lost on the IP channel, and those that
				have been received but then discarded by the receiving jitter buffer. It
				also reports on the combined effect of losses and discards, as both have
				equal effect on video quality.
				<vspace blankLines="1"/>
				In order to properly assess the quality of a video stream, it is
				desirable to consider the degree of burstiness of packet loss 
				<xref target="RFC3357">RFC 3357</xref>. 
				Following the one-way loss pattern sample metrics
				discussed in <xref target="RFC3357"></xref>, 
				a measure of the spacing
				between consecutive network packet loss or error events, is a ”loss
				distance”. The loss distance metric captures the spacing between the
				loss periods. The duration of a loss or error event (e.g. and how many
				packets are lost in that duration) is a “loss period”, the loss period
				metric captures the frequency and length (burstiness) of loss once it
				starts. Delay reports include the transit delay between RTP end points
				and the end system processing delays, both of which contribute to the
				user perceived delay.
				<vspace blankLines="1"/>
				Implementations MUST provide values for all the fields defined here.
				For certain metrics, if the value is undefined or unknown, then the
				specified default or unknown field value MUST be provided.
				<vspace blankLines="1"/>
				The block is encoded as six 32-bit words:

<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |FT |  reserved |        block length           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        SSRC of source                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|   Loss rate   |  Discard rate |          Loss Period          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Loss Distance         |        Max Loss Duration      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Round trip delay          |       End system delay        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Gmin      |   RX config   |          JB nominal           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|          JB maximum           |          JB abs max           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

				<list style="hanging">
					<t hangText="block type (BT): 8 bits">
						<vspace blankLines="0"/>
						A Video Stream Metrics Report Block is identified by the constant <VSM>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Frame type indicator (FT): 2 bits">
						<vspace blankLines="0"/>
						This field is used to indicate the frame type to be
						reported. Bits set to 01 if the Loss rate field and discard rate
						field contain a I_frame report, 10 if the Loss rate field and discard
						rate field contain a P frame report, 11 if the Loss rate field and
						discard rate field contain a B frame report, 00 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="reserved: 6 bits">
						<vspace blankLines="0"/>
						This field is reserved for future definition. In the absence of such a
						definition, the bits in this field MUST be set to zero and MUST be
						ignored by the receiver. 
						<vspace blankLines="1"/>
					</t>
					<t hangText="block length: 16 bits">
						<vspace blankLines="0"/>
						The constant 8,
						in accordance with the definition of this field in Section 3 of 
						<xref target="RFC3611">RFC 3611</xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="SSRC of source: 32 bits">
						<vspace blankLines="0"/>
						The SSRC of the RTP data packet source being reported upon by this
						report block. 
						in accordance with the definition of this field in Section 3 of 
						<xref target="RFC3611">RFC 3611</xref>.
					</t>
				</list>
				The remaining fields are described in the following four sections:
				Packet Loss and Discard Metrics, Delay Metrics, Configuration Metrics,
				and Jitter Buffer Parameters. 
			</t>

			<section title="Packet Loss and Discard Metrics">
				<t>
					It is very useful to distinguish between packets lost by the
					network and those discarded due to jitter. Both have equal effect on
					the quality of the video stream, however, having separate counts helps
					identify the source of quality degradation. These fields MUST be
					populated, and MUST be set to zero if no packets have been
					received.
					<vspace blankLines="1"/>
					<list style="hanging">
						<t hangText="Loss rate for I-Frame packets: 8 bits">
							<vspace blankLines="0"/> 
							The fraction of RTP data packets from the source
							lost since the beginning of reception, expressed as a fixed point
							number with the binary point at the left edge of the field. This
							value is calculated by dividing the total number of I frame
							packets lost (after the effects of applying any error protection
							such as FEC) by the total number of packets expected, multiplying
							the result of the division by 256, limiting the maximum value to
							255 (to avoid overflow), and taking the integer part. The numbers
							of duplicated packets and discarded packets do not enter into this
							calculation. Since receivers cannot be required to maintain
							unlimited buffers, a receiver MAY categorize late-arriving packets
							as lost. The degree of lateness that triggers a loss SHOULD be
							significantly greater than that which triggers a discard.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Discard rate for I-Frame packets: 8 bits">
							<vspace blankLines="0"/>
							The fraction of RTP data packets from the source
							that have been discarded since the beginning of reception, due to
							late or early arrival, under-run or overflow at the receiving
							jitter buffer. This value is expressed as a fixed point number
							with the binary point at the left edge of the field. It is
							calculated by dividing the total number of I-Frame packets
							discarded (excluding duplicate packet discards) by the total number
							of packets expected, multiplying the result of the division by
							256, limiting the maximum value to 255 (to avoid overflow), and
							taking the integer part.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Loss rate for P-Frame packets: 8 bits">
							<vspace blankLines="0"/>
							The loss rate for P-Frame packets is similar to
							the loss rate for I-Frame packets. The value is calculated by
							dividing the total number of P frame packets lost (after the
							effects of applying any error protection such as FEC) by the total
							number of packets expected, multiplying the result of the division
							by 256.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Discard rate for P-Frame packets: 8 bits">
							<vspace blankLines="0"/>
							The discard rate for P-Frame packets is similar
							to the discard rate for I-Frame packets. The value is calculated
							by dividing the total number of P-Frame packets discarded (excluding
							duplicate packet discards) by the total number of packets
							expected, multiplying the result of the division by 256.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Loss rate for B-Frame packets: 8 bits">
							<vspace blankLines="0"/>
							The loss rate for B-Frame packets is similar to
							the loss rate for P-Frame packets. The value is calculated by
							dividing the total number of B frame packets lost (after the
							effects of applying any error protection such as FEC) by the total
							number of packets expected, multiplying the result of the division
							by 256.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Discard rate for P-Frame packets: 8 bits">
							<vspace blankLines="0"/> 
							The discard rate for B-Frame packets is similar
							to the discard rate for P-Frame packets. The value is calculated
							by dividing the total number of B-Frame packet discarded (excluding
							duplicate packet discards) by the total number of packets
							expected, multiplying the result of the division by 256.
						</t>
					</list>
				</t>
			</section>

			<section title="Burst Metrics">
				<t>	
					<list style="hanging">
						<t hangText="Loss Distance: 16 bits">
							<vspace blankLines="0"/>
							The mean duration, expressed in milliseconds, of the loss intervals
							that have occurred since the beginning of reception 
							<xref target="DSLF"></xref>. The duration of each loss distance is
							calculated based upon the frames that mark the beginning and end
							of that period. It is equal to the timestamp of the end frame,
							plus the duration of the end frame, minus the timestamp of the
							beginning frame. If the actual values are not available, estimated
							values MUST be used. If there have been no burst periods, the
							burst duration value MUST be zero.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Loss Period: 16 bits">
							<vspace blankLines="0"/>
							The mean duration, expressed in milliseconds, of the burst loss
							periods that have occurred since the beginning of reception 
							<xref target="DSLF"></xref>. The duration of each period is calculated
							based upon the frame that marks the end of the prior burst loss
							and the frame that marks the beginning of the subsequent burst
							loss. It is equal to the timestamp of the subsequent burst frame,
							minus the timestamp of the prior burst packet, plus the duration
							of the prior burst packet. If the actual values are not available,
							estimated values MUST be used. In the case of a gap that occurs at
							the beginning of reception, the sum of the timestamp of the prior
							burst packet and the duration of the prior burst packet are
							replaced by the reception start time. In the case of a gap that
							occurs at the end of reception, the timestamp of the subsequent
							burst packet is replaced by the reception end time. If there have
							been no gap periods, the gap duration value MUST be zero.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Max Loss Duration of a single error: 16 bits">
							<vspace blankLines="0"/>
							The maximum loss duration, expressed in
							milliseconds, of the loss periods that have occurred since the
							beginning of reception. The recommended max loss duration is
							specified as less than 16 ms in <xref target="DSLF"></xref>,
							which provides a balance between interleaver depth protection from
							xDSL errors induced by impulse noise, delay added to other
							applications and video service QoE requirements to reduce visible
							impairments.
						</t>
					</list>
				</t>
			</section>

			<section title="Delay Metrics">
				<t>
					Similar to the delay metrics for audio stream defined in the
					section 4.7.3 of <xref target="RFC3611"></xref>, the delay metrics for
					video stream fall into two categories: end-system delay due to RTP
					payload multiplexing and round trip delay due to multiplexing RTP
					frames within a UDP frame.
					<vspace blankLines="1"/>
					<list style="hanging">
						<t hangText="Round trip delay: 16 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.3 of <xref target="RFC3611"></xref>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="End system delay: 16 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.3 of <xref target="RFC3611"></xref>.
							<vspace blankLines="1"/>
						</t>
					</list>
				</t>
			</section>

			<section title="Configuration Parameter Metrics">
				<t>
					Similar to the configuration metrics defined in the section 4.7.6
					of <xref target="RFC3611"></xref>, the configuration metrics for video
					stream include Gmin, receiver configuration byte, packet loss
					concealment, jitter buffer adaptive, and jitter buffer rate.
					<vspace blankLines="1"/>
					<list style="hanging">
						<t hangText="Gmin: 8 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.6 of <xref target="RFC3611"/>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Receiver configuration byte (RX config): 8 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.6 of <xref target="RFC3611"/>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Jitter buffer adaptive (JBA): 2 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.6 of <xref target="RFC3611"/>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Jitter buffer rate (JB rate): 4 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.6 of <xref target="RFC3611"/>.
							<vspace blankLines="1"/>
						</t>
					</list>
				</t>
			</section>

			<section title="Jitter Buffer Parameters">
				<t>
					Similar to the jitter buffer parameters defined in the section
					4.7.7 of <xref target="RFC3611"/>, 
					the Jitter Buffer Parameters for video streams
					include jitter buffer nominal delay, jitter buffer maximum delay and
					jitter buffer absolute maximum delay.
					<vspace blankLines="1"/>
					<list style="hanging">
						<t hangText="Jitter buffer nominal delay (JB nominal): 16 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.7 of<xref target="RFC3611"></xref>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Jitter buffer maximum delay (JB maximum): 16 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.7 of<xref target="RFC3611"></xref>.
							<vspace blankLines="1"/>
						</t>
						<t hangText="Jitter buffer absolute maximum delay (JB abs max): 16 bits">
							<vspace blankLines="0"/>
							As defined in Section 4.7.7 of<xref target="RFC3611"></xref>.
							<vspace blankLines="1"/>
						</t>
					</list>
				</t>
			</section>
		</section>

		<section anchor="PQM" title="Perceptual Quality Metrics Report Block">
			<t>
				This block reports perceptual quality metrics beyond the
				information carried in the standard RTCP packet format. Information is
				recorded about Video MOS, Audio Video MOS, Video Service Transmission
				Quality, Video Service Audio Quality, Video Service Multimedia Quality and
				Video Service Picture Quality.
				<vspace blankLines="1"/>
				The report block contents are dependent upon a series of flag bits
				carried in the first part of the header. Not all parameters need to be
				reported in each block. Flags indicate which are and which are not
				reported. The fields corresponding to unreported parameters MUST be
				present, but are set to zero. The receiver MUST ignore any Perceptual Quality Metrics Block
				with a non-zero value in any field flagged as unreported.
				<vspace blankLines="1"/>
				The Perceptual Quality Metrics Block has the following format:

<figure><artwork>
 0                   1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     BT=TBD    |I|S|T|A|M|P|Rsd|         block length          |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                        SSRC of source                         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|              MOS-V            |           MOS-AV              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|              VSTQ             |           VSAQ                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|              VSMQ             |           VSPQ                |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|        Loss Period VSPQ       |    Loss Distance VSPQ         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</artwork></figure>

				<list style="hanging">
					<t hangText="Block type (BT): 8 bits">
						<vspace blankLines="0"/>
						The Perceptual Quality Metrics Block is identified by the constant <PQM>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Interval Metric flag (I): 1 bit ">
						<vspace blankLines="0"/>
						This field is used to indicate whether the Basic
						Loss/Discard metrics are Interval or Cumulative metrics, that is,
						whether the reported values applies to the most recent measurement
						interval duration between successive metrics reports (I=1) (the
						Interval Duration) or to the accumulation period characteristic of
						cumulative measurements (I=0) (the Cumulative Duration). 
						<vspace blankLines="1"/>
					</t>
					<t hangText="MOS-V flag (S): 1 bit ">
						<vspace blankLines="0"/>
						Bit set to 1 if the MOS-V field and MOS-AV field contain a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Video Service Transmission Quality flag (T): 1 bit ">
						<vspace blankLines="0"/>
						Bit set to 1 if the VSTQ field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Video Service Audio Quality flag (A): 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the VSAQ field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Video Service Multimedia Quality flag (M): 1 bit">
						<vspace blankLines="0"/>
						Bit set to 1 if the VSMQ field contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Video Service Picture Quality flag (P): 1 bit ">
						<vspace blankLines="0"/>
						Bit set to 1 if the VSPQ field, Loss Period VSPQ, 
						Loss Distance VSPQ contains a report, 0 otherwise.
						<vspace blankLines="1"/>
					</t>
					<t hangText="Rsd.: 2 bits ">
						<vspace blankLines="0"/>
						This field is reserved for future definition. In the absence of such a definition,
						the bits in this field MUST be set to zero and MUST be ignored by
						the receiver.
						<vspace blankLines="1"/>
					</t>
					<t hangText="SSRC of source: 32 bits">
						<vspace blankLines="0"/>
						As defined in Section 4.1 of <xref target="RFC3611"></xref>.
						<vspace blankLines="1"/>
					</t>
					<t hangText="MOS-V: 16 bits">
						<vspace blankLines="0"/>
						The estimated mean opinion score for video quality (MOS-V) is a video quality
						metric on a scale from 1 to 5, in which 5 represents excellent and 1
						represents unacceptable. This metric is defined as not including the
						effects of audio impairments and can be compared to MOS scores
						obtained from video quality tests. It is expressed as an integer in
						the range 10 to 50, corresponding to MOS x 10. For example, a value
						of 35 would correspond to an estimated MOS score of 3.5.
						<vspace blankLines="1" /> 
						A value of 127 indicates that this parameter is
						unavailable. Values other than 127 and the valid range defined above
						MUST NOT be sent and MUST be ignored by the receiving system.
						<vspace blankLines="1"/>
					</t>
					<t hangText="MOS-AV: 16 bits">
						<vspace blankLines="1" /> 
						The estimated mean opinion score for Audio-Video quality (MOS-AV) is
						defined as including the effects of delay and other effects that
						would affect Audio-Video quality. It is expressed as an integer in
						the range 10 to 50, corresponding to MOS x 10, as for MOS-AV. A
						value of 127 indicates that this parameter is unavailable. Values
						other than 127 and the valid range defined above MUST NOT be sent
						and MUST be ignored by the receiving system. 
						<vspace blankLines="1"/>
					</t>
					<t hangText="VSTQ: 16 bits">
						<vspace blankLines="0"/>
						Video Service Transmission Quality (TBC)
						<vspace blankLines="1"/>
					</t>
					<t hangText="VSAQ: 16 bits">
						<vspace blankLines="0"/>
						Video Service Audio Quality (TBC)
						<vspace blankLines="1"/>
					</t>
					<t hangText="VSMQ: 16 bits">
						<vspace blankLines="0"/>
						Video Service Multimedia Quality (TBC)
						<vspace blankLines="1"/>
					</t>
					<t hangText="VSPQ: 16 bits">
						<vspace blankLines="0"/>
						Video Service Picture Quality (TBC)
						<vspace blankLines="1"/>
					</t>
					<t hangText="Loss Period VSPQ: 16 bits">
						<vspace blankLines="0"/>
						Video Service Picture Quality during Loss Period (TBC)
						<vspace blankLines="1"/>
					</t>
					<t hangText="Loss Distance VSPQ: 16 bits">
						<vspace blankLines="0" />
						Video Service Picture Quality during Loss Distance (TBC)
					</t>
				</list>
			</t>
		</section>

		<section title="SDP Signaling">
			<t>
				Six new parameters are defined for the six report blocks defined in
				this document to be used with Session Description Protocol (SDP) 
				<xref target="RFC4566"></xref> using the Augmented Backus-Naur Form (ABNF)
				<xref target="RFC5234"></xref>. 
				They have the following syntax within the
				"rtcp-xr" attribute <xref target="RFC3611"></xref>:
<figure align="left"> <artwork>
rtcp-xr-attrib =  "a=rtcp-xr:" 
                  [xr-format *(SP xr-format)] CRLF

   xr-format = RTP-flows-syn
               / audio-video-syn
               / percept-quality-metrics
               / video-stream-metric
               / video-stat-summary
               / decodability-metric

      RTP-flows-syn = "RTP-flows-syn" 
                      ["=" max-size]
         max-size = 1*DIGIT ; maximum block size in octets

      audio-video-syn = "audio-video-syn" 
                        ["=" max-size]
         max-size = 1*DIGIT ; maximum block size in octets

      percept-quality-metrics = "percept-quality-metrics" 
                                ["=" max-size]
         max-size = 1*DIGIT ; maximum block size in octets

      video-stream-metric = "video-stream-metric" 
                            ["=" max-size]
         max-size = 1*DIGIT ; maximum block size in octets

      video-stat-summary = "video-stat-summary" 
                           ["=" stat-flag *("," stat-flag)]
         stat-flag = "I Frame loss and duplication"
                     / "P Frame loss and duplication"
                     / "B Frame loss and duplication"

      decodability-metric = "decodability-metric" 
                            ["=" stat-flag *("," stat-flag)]
         stat-flag = "Interval Metric"
                     / "MOS-V and MOS-AV"
                     / "VSTQ"
                     / "VSAQ"
                     / "VSMQ"
                     / "VSPQ"
</artwork> </figure>
				Refer to Section 5.1 of <xref target="RFC3611">RFC 3611</xref> for a
				detailed description and the full syntax of the "rtcp-xr" attribute.
			</t>
		</section>

		<section title="IANA Considerations">
		<t>
			New report block types for RTCP XR are subject to IANA registration. For
			general guidelines on IANA allocations for RTCP XR, refer to 
			<xref target="RFC3611">Section 6.2 of</xref>.
			<vspace blankLines="1"/>
			This document assigns six new block type values in the RTCP XR Block Type
			Registry:
			<list>
				<t>
					<list style="hanging" hangIndent="12">
						<t hangText="Name:">RFSD</t>
						<t hangText="Long Name:">RTP Flows Synchronization Delay</t>
						<t hangText="Value"><RFSD></t>
						<t hangText="Reference:">
							<xref target="RFSD"/>
							<vspace blankLines="1"/>
						</t>
						<t hangText="Name:">AVS</t>
						<t hangText="Long Name:">Audio-Video Synchronization</t>
						<t hangText="Value"><AVS></t>
						<t hangText="Reference:">
							<xref target="AVS"/>
							<vspace blankLines="1"/>
						</t>
						<t hangText="Name:">VSS</t>
						<t hangText="Long Name:">Video Statistics Summary</t>
						<t hangText="Value"><VSS></t>
						<t hangText="Reference:">
							<xref target="VSS"/>
							<vspace blankLines="1"/>
						</t>
						<t hangText="Name:">TDM</t>
						<t hangText="Long Name:">TR 101 290 Decodability Metrics</t>
						<t hangText="Value"><TDM></t>
						<t hangText="Reference:">
							<xref target="TDM"/>
							<vspace blankLines="1"/>
						</t>
						<t hangText="Name:">VSM</t>
						<t hangText="Long Name:">Video Stream Metrics</t>
						<t hangText="Value"><VSM></t>
						<t hangText="Reference:">
							<xref target="VSM"/>
							<vspace blankLines="1"/>
						</t>
						<t hangText="Name:">PQM</t>
						<t hangText="Long Name:">Perceptual Quality Metric</t>
						<t hangText="Value"><PQM></t>
						<t hangText="Reference:">
							<xref target="PQM"/>
							<vspace blankLines="1"/>
						</t>
					</list>					
				</t>
			</list>
			This document also registers six SDP <xref target="RFC4566"/>
			parameters for the
			"rtcp-xr" attribute in the RTCP XR SDP Parameters Registry:
			<list>
				<t>
					<list style="symbols">
						<t>"RTP-flows-syn" </t>
						<t>“audio-video-syn” </t>
						<t>“percept-quality-metrics” </t>
						<t>“video-stream-metric” </t>
						<t>“video-stat-summary” </t>
						<t>“decodability-metric” </t>
					</list>
				</t>
			</list>
			<vspace blankLines="1"/>
			The contact information for the registrations is:
<figure align="center"><artwork>
Qin Wu
sunseawq@huawei.com
101 Software Avenue, Yuhua District 
Nanjing, JiangSu 210012 China
</artwork></figure>
			</t>
		</section>

		<section title="Security Considerations">
			<t>TBC</t>
		</section>

		<section title="Acknowledgements">
			<t>
				The authors would like to thank Youqing Yang, Wenxiao Yu and Yinliang Hu
				for their valuable comments and suggestions on this document.
			</t>
		</section>
	</middle>

	<back>
		<references title="Normative References">
			&I-D.ietf-avt-rapid-rtp-sync;
			&I-D.ietf-avt-rtp-svc;
			&rfc2250;
			&rfc3611;
			&rfc2119;
			&rfc4566;
			&rfc5234;
			&rfc3550;
			<reference anchor="ETSI">
				<front>
					<title>Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems</title>
					<author>
						<organization>ETSI</organization>
					</author>
					<date year="2001" />
				</front>
				<seriesInfo name="Technical Report" value="TR 101 290"/>
			</reference>
			<reference anchor="ISO-IEC.13818-1.2007">
				<front>
					<title>Information technology - Generic coding of moving pictures and associated audio information: Systems</title>
					<author>
						<organization>International Organization for Standardization</organization>
					</author>
					<date month="October" year="2007" />
				</front>
				<seriesInfo name="ISO" value="International Standard 13818-1" />
			</reference>
		</references>

		<references title="Informative References">
			&rfc3357;
			<reference anchor="DSLF">
				<front>
					<title>Triple-play Services Quality of Experience (QoE) Requirements</title>
					<author fullname="Tim Rahrer" initials="T.R." role="editor" surname="Rahrer">
						<organization>Nortel</organization>
						<address>
							<postal>
								<street>3500 Carling Ave.</street>
								<city>Ottawa</city>
								<region>Ontario</region>
								<country>Canada</country>
							</postal>
							<phone>+1.613.763.4479</phone>
							<email>tim.rahrer@nortel.com</email>
						</address>
					</author>
					<author fullname="Riccardo Fiandra" role="editor" surname="Fiandra">
						<organization>FastWeb, SpA</organization>
						<address>
							<email>riccardo.fiandra@fastweb.it</email>
						</address>
					</author>
					<author fullname="Steven Wright" role="editor" surname="Wright">
						<organization>BellSouth Telecommunications</organization>
						<address>
							<email>steven.wright@bellsouth.com</email>
						</address>
					</author>
					<date day="13" month="December" year="2006" />
				</front>
				<seriesInfo name="DSL Forum Technical Report" value="TR-126"/>
			</reference>
		</references>
	</back>
</rfc>

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