Internet Engineering Task Force (IETF) G. Zorn
Request for Comments: 7004 Network Zen
Category: Standards Track R. Schott
ISSN: 2070-1721 Deutsche Telekom
Q. Wu, Ed.
R. Huang
Huawei
September 2013
Internet Engineering Task Force (IETF) G. Zorn
Request for Comments: 7004 Network Zen
Category: Standards Track R. Schott
ISSN: 2070-1721 Deutsche Telekom
Q. Wu, Ed.
R. Huang
Huawei
September 2013
RTP Control Protocol (RTCP) Extended Report (XR) Blocks for Summary Statistics Metrics Reporting
RTP控制协议（RTCP）扩展报告（XR）块，用于汇总统计指标报告
Abstract
摘要
This document defines three RTP Control Protocol (RTCP) Extended Report (XR) blocks that allow the reporting of loss, duplication, and discard summary statistics metrics in a range of RTP applications.
本文档定义了三个RTP控制协议（RTCP）扩展报告（XR）块，允许在一系列RTP应用程序中报告丢失、重复和丢弃摘要统计指标。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7004.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc7004.
Copyright Notice
版权公告
Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2013 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................2
1.1. Summary Statistics Metrics .................................2
1.2. RTCP and RTCP Extended Reports .............................3
1.3. Performance Metrics Framework ..............................3
1.4. Applicability ..............................................3
2. Terminology .....................................................3
3. Transport-Related End-System Metrics ............................4
3.1. Burst/Gap Loss Summary Statistics Block ....................4
3.1.1. Report Block Structure ..............................5
3.1.2. Definition of Fields in Loss Summary
Statistics Block ....................................5
3.2. Burst/Gap Discard Summary Statistics Block .................7
3.2.1. Report Block Structure ..............................8
3.2.2. Definition of Fields in Burst/Gap Discard
Summary Statistics Block ............................8
4. Application-Level Metrics ......................................10
4.1. Frame Impairment Statistics Summary Block .................10
4.1.1. Report Block Structure .............................11
4.1.2. Definition of Fields in Frame Impairment
Statistics Summary Block ...........................11
5. SDP Signaling ..................................................13
5.1. SDP rtcp-xr Attribute Extension ...........................13
5.2. Offer/Answer Usage ........................................13
6. IANA Considerations ............................................13
6.1. New RTCP XR Block Type Values .............................13
6.2. New RTCP XR SDP Parameters ................................14
6.3. Contact Information for Registrations .....................14
7. Security Considerations ........................................14
8. Acknowledgements ...............................................14
9. References .....................................................14
9.1. Normative References ......................................14
9.2. Informative References ....................................15
Appendix A. Metrics Represented Using the Template from RFC 6390 .16
1. Introduction ....................................................2
1.1. Summary Statistics Metrics .................................2
1.2. RTCP and RTCP Extended Reports .............................3
1.3. Performance Metrics Framework ..............................3
1.4. Applicability ..............................................3
2. Terminology .....................................................3
3. Transport-Related End-System Metrics ............................4
3.1. Burst/Gap Loss Summary Statistics Block ....................4
3.1.1. Report Block Structure ..............................5
3.1.2. Definition of Fields in Loss Summary
Statistics Block ....................................5
3.2. Burst/Gap Discard Summary Statistics Block .................7
3.2.1. Report Block Structure ..............................8
3.2.2. Definition of Fields in Burst/Gap Discard
Summary Statistics Block ............................8
4. Application-Level Metrics ......................................10
4.1. Frame Impairment Statistics Summary Block .................10
4.1.1. Report Block Structure .............................11
4.1.2. Definition of Fields in Frame Impairment
Statistics Summary Block ...........................11
5. SDP Signaling ..................................................13
5.1. SDP rtcp-xr Attribute Extension ...........................13
5.2. Offer/Answer Usage ........................................13
6. IANA Considerations ............................................13
6.1. New RTCP XR Block Type Values .............................13
6.2. New RTCP XR SDP Parameters ................................14
6.3. Contact Information for Registrations .....................14
7. Security Considerations ........................................14
8. Acknowledgements ...............................................14
9. References .....................................................14
9.1. Normative References ......................................14
9.2. Informative References ....................................15
Appendix A. Metrics Represented Using the Template from RFC 6390 .16
This document defines three new block types to augment those defined in [RFC3611] for use in a range of RTP applications:
本文件定义了三种新的块类型，以补充[RFC3611]中定义的用于一系列RTP应用的块类型：
o Burst/Gap Loss Summary Statistics Block
o 突发/间隙丢失汇总统计数据块
o Burst/Gap Discard Summary Statistics Block
o 突发/间隙丢弃摘要统计数据块
o Frame Impairment Statistics Summary Block
o 帧损坏统计信息摘要块
The first two block types support the reporting of burst/gap loss and burst/gap discard summary statistics including packet loss/discard proportion, mean, and variance and belong to the class of transport-related end-system metrics defined in [RFC6792]. These two blocks are intended to be used in conjunction with information from the Burst/Gap Loss Metrics Block [RFC6958] or Burst/Gap Discard Metrics Block [RFC7003], on which these two blocks therefore depend. The metrics in the Burst/Gap Loss Metrics Block and Burst/Gap Discard Metrics Block are consistent with the definitions of "burst", "gap", "loss", and "discard" in RTCP XR [RFC3611].
前两种块类型支持报告突发/间隔丢失和突发/间隔丢弃汇总统计信息，包括数据包丢失/丢弃比例、平均值和方差，属于[RFC6792]中定义的传输相关终端系统指标类别。这两个块拟与来自突发/间隙丢失度量块[RFC6958]或突发/间隙丢弃度量块[RFC7003]的信息一起使用，因此这两个块依赖于该信息块。突发/间隔丢失度量块和突发/间隔丢弃度量块中的度量与RTCP XR[RFC3611]中“突发”、“间隔”、“丢失”和“丢弃”的定义一致。
The third block supports the reporting of detailed video statistics for each frame type, including the number of frames received, lost, and discarded of each frame type in the Group of Pictures (GOP) and additional data allowing the calculation of statistical parameters (e.g., the proportion of each frame type impaired by packet loss and discard). The metrics defined in this block belong to the class of application-level metrics defined in [RFC6792].
第三块支持报告每种帧类型的详细视频统计信息，包括图片组（GOP）中每种帧类型的接收、丢失和丢弃的帧数，以及允许计算统计参数的附加数据（例如，每种帧类型因分组丢失和丢弃而受损的比例）. 此块中定义的度量属于[RFC6792]中定义的应用程序级度量类别。
The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 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].
[RFC3550]中定义了使用RTCP进行报告。[RFC3611]定义了使用RTCP扩展报告（XR）进行报告的可扩展结构。本文档定义了一个新的扩展报告块，用于[RFC3550]和[RFC3611]。
The RTP Monitoring Framework [RFC6792] provides guidelines for reporting block format using RTCP XR. Metrics described in this document are in accordance with the guidelines in [RFC6792].
RTP监控框架[RFC6792]提供了使用RTCP XR报告块格式的指南。本文件中描述的指标符合[RFC6792]中的指南。
These metrics are applicable to a wide range of RTP applications and reflect transient IP problems that affect user experience. They can be used to form an accurate assessment of users' quality of experience and influence sender strategies to mitigate the problem.
这些指标适用于广泛的RTP应用程序，并反映影响用户体验的瞬时IP问题。它们可用于准确评估用户的体验质量，并影响发送者策略以缓解问题。
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].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
In addition, the following term is defined:
此外，定义了以下术语：
Frame Type
框架类型
In many cases, a video frame is compressed using different algorithms. Frame type is used to identify different algorithms for video frames. Two frame types used in the different video algorithms are the Key frame and Derived frames. The Key frame is independently coded without prediction from other pictures and used as a reference frame for predicting other pictures. Derived frames are predicatively coded and derived from a Key frame using a prediction algorithm. If there is no video image compression, all frames are Key frames.
在许多情况下，视频帧使用不同的算法进行压缩。帧类型用于识别视频帧的不同算法。不同视频算法中使用的两种帧类型是关键帧和派生帧。该关键帧被独立地编码而不从其他图片进行预测，并且用作预测其他图片的参考帧。使用预测算法对导出帧进行预测编码并从关键帧导出。如果没有视频图像压缩，则所有帧都是关键帧。
This block extends packet loss and discard metrics defined in Section 4.7.1 of [RFC3611]. The metrics described here are intended to be used as described in this section, in conjunction with information from the Measurement Information Block [RFC6776] (which MUST be present in the same RTCP packet as the Burst/Gap Loss Metrics Block [RFC6958]) and also with the metric "cumulative number of packets lost" provided in standard RTCP [RFC3550]. Instances of this metrics block use the synchronization source (SSRC) to refer to the separate auxiliary Measurement Information Block [RFC6776], which describes measurement periods in use (see [RFC6776], Section 4.2). This metrics block relies on the measurement period in the Measurement Information Block indicating the span of the report and SHOULD be sent in the same compound RTCP packet as the Measurement Information Block. If the measurement period is not received in the same compound RTCP packet as this metrics block, this metrics block MUST be discarded.
该块扩展了[RFC3611]第4.7.1节中定义的数据包丢失和丢弃度量。此处描述的指标拟与本节所述的指标结合使用，包括来自测量信息块[RFC6776]（必须与突发/间隙丢失指标块[RFC6958]存在于同一RTCP数据包中）的信息，以及标准RTCP中提供的指标“累计数据包丢失数”[RFC3550]。此度量块的实例使用同步源（SSRC）引用单独的辅助度量信息块[RFC6776]，该信息块描述了使用中的度量周期（请参见[RFC6776]，第4.2节）。此度量块依赖于度量信息块中指示报告范围的度量周期，并应在与度量信息块相同的复合RTCP数据包中发送。如果度量周期未在与此度量块相同的复合RTCP数据包中接收，则必须丢弃此度量块.
The metrics carried in this metrics block provide information relevant to statistical parameters, including Burst Loss Rate, Gap Loss Rate, Burst Duration Mean, and Burst Duration Variance, and are measured at the receiving end of the RTP stream using burst/gap loss metrics defined in [RFC6958] and other information that is sent together with this report block.
该度量块中携带的度量提供与统计参数相关的信息，包括突发丢失率、间隙丢失率、突发持续时间平均值和突发持续时间方差，并使用[RFC6958]中定义的突发/间隙丢失度量在RTP流的接收端进行测量以及与此报告块一起发送的其他信息。
The structure of the Burst/Gap Loss Summary Statistics Block is as follows.
突发/间隙丢失汇总统计块的结构如下所示。
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=17 | I | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Loss Rate | Gap Loss Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Duration Mean | Burst Duration Variance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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=17 | I | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Loss Rate | Gap Loss Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Duration Mean | Burst Duration Variance |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Block Type (BT): 8 bits
块类型（BT）：8位
A Burst/Gap Loss Summary Statistics Block is identified by the constant 17.
突发/间隙丢失汇总统计数据块由常数17标识。
Interval Metric flag (I): 2 bits
间隔度量标志（I）：2位
This field is used to indicate whether the burst/gap loss summary statistics metrics are Sampled, Interval, or Cumulative metrics:
此字段用于指示突发/间隔损失汇总统计指标是采样的、间隔的还是累积的：
I=10: Interval Duration - the reported value applies to the most recent measurement interval duration between successive metrics reports.
I=10：间隔持续时间-报告值适用于连续度量报告之间的最新度量间隔持续时间。
I=11: Cumulative Duration - the reported value applies to the accumulation period characteristic of cumulative measurements.
I=11：累积持续时间-报告值适用于累积测量的累积周期特征。
I=01: Sampled Value - the reported value is a sampled instantaneous value.
I=01：采样值-报告值为采样瞬时值。
In this document, the value I=00 is the reserved value and MUST NOT be used.
在本文件中，值I=00为保留值，不得使用。
Reserved: 6 bits
保留：6位
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 4.2).
此字段保留供将来定义。在没有此类定义的情况下，此字段中的位必须设置为零并被接收器忽略（见[RFC6709]，第4.2节）。
Block Length: 16 bits
块长度：16位
The constant 3, in accordance with the definition of this field in Section 3 of RFC 3611 [RFC3611].
常数3，符合RFC 3611[RFC3611]第3节中该字段的定义。
SSRC of Source: 32 bits
源的SSRC：32位
As defined in Section 4.1 of RFC 3611 [RFC3611].
如RFC 3611[RFC3611]第4.1节所定义。
Burst Loss Rate: 16 bits
突发丢失率：16位
The fraction of packets lost during bursts since the beginning of reception, expressed as a fixed point number with the binary point immediately after the left-most bit. This value is calculated by dividing Packets Lost in Bursts by Total Packets Expected in Bursts, multiplying the result of the division by 32768 (0x8000), and keeping only the integer part. The maximum value is thus 0x8000. Representing this as a formula:
自接收开始以来，在突发过程中丢失的数据包的分数，表示为固定点数，二进制点紧跟在最左边的位之后。该值的计算方法是将突发中丢失的数据包除以突发中预期的数据包总数，将除法结果乘以32768（0x8000），并仅保留整数部分。因此，最大值为0x8000。将其表示为公式：
integer-part( (Packets Lost in Bursts / Total Packets Expected in Bursts) * 0x8000 )
整数部分（（突发中丢失的数据包/突发中预期的数据包总数）*0x8000）
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
Gap Loss Rate: 16 bits
间隙丢失率：16位
The fraction of packets lost during gaps since the beginning of reception expressed as a fixed point number with the binary point immediately after the left-most bit. This value is calculated by dividing the difference between number of packets lost and Packets Lost in Bursts by the difference between Packets Expected and Total Packets Expected in Bursts, multiplying the result of the division by 32768 (0x8000), and keeping only the integer part. The maximum value is thus 0x8000. Representing this as a formula:
自接收开始以来在间隔期间丢失的数据包分数，表示为固定点数，二进制点紧跟在最左边的位之后。通过将丢失的数据包数与突发中丢失的数据包数之差除以预期数据包数与突发中预期数据包总数之差，将除法结果乘以32768（0x8000），并仅保留整数部分来计算该值。因此，最大值为0x8000。将其表示为公式：
integer-part ( (number of packets lost - Packets Lost in Bursts)/
(Packets Expected - Total Packets Expected in Bursts) * 0x8000 )
integer-part ( (number of packets lost - Packets Lost in Bursts)/
(Packets Expected - Total Packets Expected in Bursts) * 0x8000 )
where "number of packets lost" is obtained from standard RTCP [RFC3550] and Packets Expected is calculated as the difference between "extended last sequence number" and "extended first
其中，从标准RTCP[RFC3550]获得“丢失的数据包数”，预期数据包计算为“扩展的最后序列号”和“扩展的第一序列号”之间的差值
sequence number" (Interval or Cumulative) provided in the Measurement Identity and Information Block [RFC6776].
测量标识和信息块[RFC6776]中提供的序列号“（间隔或累积）。
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
Note that if the metric is to be calculated on an Interval basis, a difference must be taken between the current and preceding values of "cumulative number of packets lost" in RTCP to obtain the "number of packets lost" for the reporting interval.
请注意，如果要在间隔基础上计算度量，则必须在RTCP中“累计丢失数据包数”的当前值和之前值之间取一个差值，以获得报告间隔的“丢失数据包数”。
Burst Duration Mean: 16 bits
突发持续时间平均值：16位
The mean burst duration is obtained as the quotient:
平均突发持续时间为商：
mean = Sum of Burst Durations / Number of Bursts
平均值=突发持续时间之和/突发次数
where "Sum of Burst Durations" and "Number of Bursts" is obtained from the RTCP XR Burst/Gap Loss Metrics Block [RFC6958].
其中“突发持续时间之和”和“突发数”是从RTCP XR突发/间隙损失度量块[RFC6958]获得的。
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
Burst Duration Variance: 16 bits
突发持续时间方差：16位
The variance of the burst duration is obtained using the standard result:
使用标准结果获得突发持续时间的方差：
var = ( Sum of Squares of Burst Durations - Number of Bursts *
mean^2 ) / (Number of Bursts - 1)
var = ( Sum of Squares of Burst Durations - Number of Bursts *
mean^2 ) / (Number of Bursts - 1)
where "Sum of Squares of Burst Durations" and "Number of Bursts" is obtained from the RTCP XR Burst/Gap Loss Metrics Block [RFC6958].
其中“突发持续时间的平方和”和“突发数”是从RTCP XR突发/间隙损失度量块[RFC6958]获得的。
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
This block extends packet loss and discard metrics defined in Section 4.7.1 of [RFC3611]. The metrics described here are intended to be used as described in this section, in conjunction with information from the Measurement Identity Block [RFC6776] (which MUST be present in the same RTCP packet as the Burst/Gap Discard Summary Statistics Block).
该块扩展了[RFC3611]第4.7.1节中定义的数据包丢失和丢弃度量。此处描述的指标旨在与测量标识块[RFC6776]（必须与突发/间隙丢弃汇总统计数据块位于同一RTCP数据包中）的信息一起使用，如本节所述。
These metrics provide information relevant to statistical parameters, including Burst Discard Rate and Gap Discard Rate, and are measured at the receiving end of the RTP stream using burst/gap discard metrics defined in [RFC7003] and other information that is sent together with this report block.
这些度量提供与统计参数相关的信息，包括突发丢弃率和间隙丢弃率，并在RTP流的接收端使用[RFC7003]中定义的突发/间隙丢弃度量以及与此报告块一起发送的其他信息进行测量。
Instances of this metrics block use the synchronization source (SSRC) to refer to the separate auxiliary Measurement Information block [RFC6776] that describes measurement periods in use (see [RFC6776], Section 4.2). This metrics block relies on the measurement period in the Measurement Information Block indicating the span of the report and SHOULD be sent in the same compound RTCP packet as the measurement information block. If the measurement period is not received in the same compound RTCP packet as this metrics block, this metrics block MUST be discarded.
此度量块的实例使用同步源（SSRC）引用单独的辅助度量信息块[RFC6776]，该信息块描述了使用中的度量周期（请参见[RFC6776]，第4.2节）。此度量块依赖于度量信息块中指示报告范围的度量周期，并且应在与度量信息块相同的复合RTCP数据包中发送。如果测量周期未在与此度量块相同的复合RTCP数据包中接收，则必须丢弃此度量块。
The structure of the Burst/Gap Discard Summary Statistics Block is as follows.
突发/间隙丢弃摘要统计数据块的结构如下所示。
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=18 | I | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Discard Rate | Gap Discard Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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=18 | I | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Burst Discard Rate | Gap Discard Rate |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.2.2. Definition of Fields in Burst/Gap Discard Summary Statistics Block
3.2.2. 突发/间隙丢弃汇总统计数据块中字段的定义
Block Type (BT): 8 bits
块类型（BT）：8位
A Burst/Gap Discard Summary Statistics Block is identified by the constant 18.
突发/间隙丢弃摘要统计数据块由常数18标识。
Interval Metric flag (I): 2 bits
间隔度量标志（I）：2位
This field is used to indicate whether the burst/gap discard summary statistics metrics are Sampled, Interval, or Cumulative metrics:
此字段用于指示突发/间隔丢弃汇总统计指标是采样的、间隔的还是累积的：
I=10: Interval Duration - the reported value applies to the most recent measurement interval duration between successive metrics reports.
I=10：间隔持续时间-报告值适用于连续度量报告之间的最新度量间隔持续时间。
I=11: Cumulative Duration - the reported value applies to the accumulation period characteristic of cumulative measurements.
I=11：累积持续时间-报告值适用于累积测量的累积周期特征。
I=01: Sampled Value - the reported value is a sampled instantaneous value.
I=01：采样值-报告值为采样瞬时值。
In this document, the value I=00 is the reserved value and MUST NOT be used.
在本文件中，值I=00为保留值，不得使用。
Reserved: 6 bits
保留：6位
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 4.2).
此字段保留供将来定义。在没有此类定义的情况下，此字段中的位必须设置为零并被接收器忽略（见[RFC6709]，第4.2节）。
Block Length: 16 bits
块长度：16位
The constant 2, in accordance with the definition of this field in Section 3 of RFC 3611 [RFC3611].
常数2，符合RFC 3611[RFC3611]第3节中该字段的定义。
SSRC of Source: 32 bits
源的SSRC：32位
As defined in Section 4.1 of RFC3611 [RFC3611].
如RFC3611[RFC3611]第4.1节所定义。
Burst Discard Rate: 16 bits
突发丢弃率：16位
The fraction of packets discarded during bursts since the beginning of reception, expressed as a fixed point number with the binary point immediately after the left-most bit. This value is calculated by dividing Packets Discarded in Bursts by Total Packets Expected in Bursts, multiplying the result of the division by 32768 (0x8000), and keeping only the integer part, according to the formula:
自接收开始以来在突发过程中丢弃的数据包的分数，表示为固定点数，二进制点紧跟在最左边的位之后。根据以下公式，通过将突发中丢弃的数据包除以突发中预期的数据包总数，将除法结果乘以32768（0x8000），并仅保留整数部分来计算该值：
integer-part( (Packets Discarded in Bursts / Total Packets Expected in Bursts) * 0x8000 )
整数部分（（突发中丢弃的数据包/突发中预期的数据包总数）*0x8000）
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
Gap Discard Rate: 16 bits
间隙丢弃率：16位
The fraction of packets discarded during gaps since the beginning of reception expressed as a fixed point number with the binary point immediately after the left-most bit. This value is calculated by dividing the difference between number of packets discarded and Packets Discarded in Bursts by the difference between Packets Expected and Total Packets Expected in Bursts,
自接收开始以来在间隔期间丢弃的数据包的分数，表示为固定点数，二进制点紧跟在最左边的位之后。该值的计算方法是将丢弃的数据包数与突发丢弃的数据包数之差除以突发中预期的数据包数与预期的总数据包数之差，
multiplying the result of the division by 32768 (0x8000), and keeping only the integer part. The maximum value is thus 0x8000. Representing this as a formula:
将除法结果乘以32768（0x8000），只保留整数部分。因此，最大值为0x8000。将其表示为公式：
integer-part( (number of packets discarded - Packets Discarded in
Bursts) /(Packets Expected - Total Packets Expected in Bursts) *
0x8000 )
integer-part( (number of packets discarded - Packets Discarded in
Bursts) /(Packets Expected - Total Packets Expected in Bursts) *
0x8000 )
where "number of packets discarded" is obtained from the RTCP XR Discard Count Block [RFC7002] and filled with the sum of packets discarded due to early arrival (DT=1) and packets discarded due to late arrival (DT=2) and Packets Expected is calculated as the difference between "extended last sequence number" and "extended first sequence number" (Interval or Cumulative) provided in the Measurement Information Block [RFC6776]. In order for the Burst/ Gap Discard Summary Statistics Block to be meaningful, 2 instances of the Discard Count Block with DT=1 and DT=2 MUST be included in the same RTCP XR packet as the Burst/Gap Discard Summary Statistics Block.
其中，“丢弃的数据包数量”从RTCP XR丢弃计数块[RFC7002]中获得，并填入由于提前到达（DT=1）而丢弃的数据包和由于延迟到达（DT=2）而丢弃的数据包的总和，并将预期数据包计算为“扩展的最后序列号”和“扩展的第一序列号”之间的差值（间隔或累积）在测量信息块[RFC6776]中提供。为了使突发/间隙丢弃汇总统计数据块有意义，DT=1和DT=2的丢弃计数数据块的两个实例必须包含在与突发/间隙丢弃汇总统计数据块相同的RTCP XR数据包中。
If the measurement is unavailable, the value 0xFFFF MUST be reported.
如果测量不可用，则必须报告值0xFFFF。
This block extends the statistics summary report mechanism defined in Section 4.6 of [RFC3611] and reports statistics on which frame types were affected beyond the information carried in the Statistics Summary Report Block RTCP packet specified in Section 4.6 of [RFC3611]. Information is measured at the receiving end of the RTP stream and recorded about the number of frames received, lost frames, duplicated frames, and lost partial frames. Such information can be useful for network management and video quality monitoring.
此块扩展了[RFC3611]第4.6节中定义的统计摘要报告机制，并报告了受影响帧类型的统计信息，超出了[RFC3611]第4.6节中规定的统计摘要报告块RTCP数据包中包含的信息。在RTP流的接收端测量信息，并记录关于接收的帧数、丢失的帧、重复的帧和丢失的部分帧的信息。这些信息可用于网络管理和视频质量监控。
The structure of the Frame Impairment Statistics Summary Block is as follows.
帧损坏统计信息摘要块的结构如下所示。
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=19 |T| Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| begin_seq | end_seq |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| discarded_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| dup_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| full_lost_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| partial_lost_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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=19 |T| Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| begin_seq | end_seq |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| discarded_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| dup_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| full_lost_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| partial_lost_frames |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4.1.2. Definition of Fields in Frame Impairment Statistics Summary Block
4.1.2. 帧损坏统计信息摘要块中字段的定义
Block Type (BT): 8 bits
块类型（BT）：8位
A Frame Impairment Statistics Summary Block is identified by the constant 19.
帧损伤统计摘要块由常数19标识。
Frame type indicator (T): 1 bit
帧类型指示器（T）：1位
This field is used to indicate the frame type to be reported. The bit is set to 0 if the full_lost_frames, partial_lost_frames, dup_frames, and discarded_frames fields contain Key frame (reference frame) counts or 1 if they contain Derived frame counts. Note that if both the Key frame and Derivation frame report are sent, they should be sent in the same RTCP compound packet using two Frame Impairment Statistics Summary Blocks.
此字段用于指示要报告的帧类型。如果完整\u丢失\u帧、部分\u丢失\u帧、重复\u帧和丢弃的\u帧字段包含关键帧（参考帧）计数，则位设置为0，如果它们包含派生帧计数，则位设置为1。请注意，如果同时发送关键帧和派生帧报告，则应使用两个帧损坏统计摘要块在同一RTCP复合数据包中发送它们。
Reserved: 7 bits
保留：7位
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 4.2).
此字段保留供将来定义。在没有此类定义的情况下，此字段中的位必须设置为零并被接收器忽略（见[RFC6709]，第4.2节）。
Block Length: 16 bits
块长度：16位
The constant 6, in accordance with the definition of this field in Section 3 of RFC 3611 [RFC3611].
根据RFC 3611[RFC3611]第3节中该字段的定义，常数为6。
SSRC of Source: 32 bits
源的SSRC：32位
As defined in Section 4.1 of RFC 3611 [RFC3611].
如RFC 3611[RFC3611]第4.1节所定义。
begin_seq: 16 bits
开始顺序：16位
As defined in Section 4.1 of RFC 3611 [RFC3611].
如RFC 3611[RFC3611]第4.1节所定义。
end_seq: 16 bits
结束顺序：16位
As defined in Section 4.1 of RFC 3611 [RFC3611].
如RFC 3611[RFC3611]第4.1节所定义。
Number of discarded frames (discarded_frames): 32 bits
丢弃的帧数（丢弃的帧）：32位
Number of frames discarded in the above sequence number interval.
在上述序列号间隔中丢弃的帧数。
Number of duplicate frames (dup_frames): 32 bits
重复帧数（dup_帧）：32位
Number of duplicate frames received in the above sequence number interval.
在上述序列号间隔内接收的重复帧数。
Number of full lost frames (full_lost_frames): 32 bits
完全丢失帧数（完全丢失帧）：32位
A frame is either split across multiple packets or carried in only one packet. If the whole frame or all the packets of the frame are lost, this frame is regarded as one full_lost_frame. The full_lost_frames can be inferred from packet(s) that comprise the frame. The full_lost_frames is equivalent to the number of full lost frames in the above sequence number interval.
一个帧或者被分割成多个数据包，或者只在一个数据包中携带。如果整个帧或该帧的所有数据包丢失，则该帧被视为一个完整的丢失帧。完整的丢失帧可以从组成帧的分组中推断出来。完全丢失的帧数等于上述序列号间隔中完全丢失的帧数。
Number of partial lost frames (partial_lost_frames): 32 bits
部分丢失帧数（部分丢失帧）：32位
When a frame is split across multiple packets and some packets of the frame are lost, this frame is regarded as one partial_lost_frame. The partial_lost_frames can be inferred from packets that comprise the frame. The value of the partial_lost_frames field is equivalent to the number of partial lost frames in the above sequence number interval.
当一个帧被分割成多个包，并且该帧的一些包丢失时，该帧被视为一个部分丢失的帧。部分丢失的帧可以从组成该帧的分组中推断出来。partial_lost_frames字段的值等于上述序列号间隔中的部分丢失帧数。
RFC 3611 defines the use of SDP (Session Description Protocol) [RFC4566] for signaling the use of XR blocks. However, XR blocks MAY be used without prior signaling (see Section 5 of [RFC3611]).
RFC 3611定义了SDP（会话描述协议）[RFC4566]的使用，用于发送使用XR块的信号。但是，可以在没有事先信令的情况下使用XR块（参见[RFC3611]第5节）。
This section augments the SDP [RFC4566] attribute "rtcp-xr" defined in Section 5.1 of [RFC3611] by providing three additional values of "xr-format" to signal the use of the report block defined in this document. The ABNF [RFC5234] syntax is as follows.
本节增加了[RFC3611]第5.1节中定义的SDP[RFC4566]属性“rtcp xr”，提供了三个额外的“xr格式”值，以表示使用了本文档中定义的报告块。ABNF[RFC5234]语法如下所示。
xr-format =/ xr-bglss-block / xr-bgdss-block / xr-fiss-block xr-bglss-block = "burst-gap-loss-stat" xr-bgdss-block = "burst-gap-discard-stat" xr-fiss-block = "frame-impairment-stat"
xr format=/xr bglss block/xr bgdss block/xr fiss block xr bglss block=“突发间隔丢失统计”xr bgdss block=“突发间隔丢弃统计”xr fiss block=“帧损坏统计”
When SDP is used in offer/answer context, the SDP Offer/Answer usage defined in [RFC3611] for unilateral "rtcp-xr" attribute parameters applies. For detailed usage of Offer/Answer for unilateral parameter, refer to section 5.2 of [RFC3611].
在提供/应答上下文中使用SDP时，[RFC3611]中为单边“rtcp xr”属性参数定义的SDP提供/应答用法适用。单边参数的报价/应答的详细用法参见[RFC3611]第5.2节。
New block types for RTCP XR are subject to IANA registration. For general guidelines on IANA considerations for RTCP XR, refer to RFC 3611.
RTCP XR的新块类型需要IANA注册。有关RTCP XR的IANA注意事项的一般指南，请参阅RFC 3611。
This document assigns three new block type values in the "RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry":
本文档在“RTP控制协议扩展报告（RTCP XR）块类型注册表”中分配三个新的块类型值：
Name: BGLSS Long Name: Burst/Gap Loss Summary Statistics Block Value 17 Reference: Section 3.1
名称：BGLSS长名称：突发/间隙损耗汇总统计数据块值17参考：第3.1节
Name: BGDSS Long Name: Burst/Gap Discard Summary Statistics Block Value 18 Reference: Section 3.2
名称：BGDSS长名称：突发/间隙丢弃汇总统计数据块值18参考：第3.2节
Name: FISS Long Name: Frame Impairment Statistics Summary Block Value 19 Reference: Section 4.1
名称：FISS长名称：帧损伤统计汇总块值19参考：第4.1节
This document also registers three new SDP [RFC4566] parameters for the "rtcp-xr" attribute in the "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry":
本文档还为“RTP控制协议扩展报告（rtcp xr）会话描述协议（SDP）参数注册表”中的“rtcp xr”属性注册了三个新的SDP[RFC4566]参数：
* "burst-gap-loss-stat" * "burst-gap-discard-stat" * "frame-impairment-stat"
* “突发间隔丢失统计”*“突发间隔丢弃统计”*“帧损坏统计”
The contact information for the registrations is:
注册的联系信息为：
Qin Wu (sunseawq@huawei.com) 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China
秦武(sunseawq@huawei.com)中国江苏省南京市雨花区软件大道101号210012
The new RTCP XR blocks in this document do not introduce any new security considerations beyond those described in [RFC3611].
除[RFC3611]中所述的安全注意事项外，本文档中的新RTCP XR块未引入任何新的安全注意事项。
The authors would like to thank Bill Ver Steeg, David R. Oran, Ali Begen, Colin Perkins, Roni Even, Youqing Yang, Wenxiao Yu, Yinliang Hu, Jing Zhao, Ray van Brandenburg, Claire Bi, Dan Romascanu, Alfred Morton, Jr., Klaas Wierenga, Barry Leiba, Robert Sparks, Ralph Droms, and Benoit Claise for their valuable comments and suggestions on this document.
作者要感谢比尔·弗斯泰格、大卫·R·奥兰、阿里·贝根、科林·帕金斯、罗尼·埃文、杨有庆、文晓宇、胡银良、赵静、雷·范·勃兰登堡、克莱尔·比、丹·罗马斯坎努、小阿尔弗雷德·莫顿、克拉斯·维伦加、巴里·莱巴、罗伯特·斯帕克斯、拉尔夫·德罗姆斯、，和Benoit Claise，感谢他们对本文件的宝贵意见和建议。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", STD 64, RFC 3550, July 2003.
[RFC3550]Schulzrinne，H.，Casner，S.，Frederick，R.，和V.Jacobson，“RTP：实时应用的传输协议”，STD 64，RFC 35502003年7月。
[RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003.
[RFC3611]Friedman，T.，Caceres，R.，和A.Clark，“RTP控制协议扩展报告（RTCP XR）”，RFC 36112003年11月。
[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, July 2006.
[RFC4566]Handley，M.，Jacobson，V.，和C.Perkins，“SDP：会话描述协议”，RFC4566，2006年7月。
[RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008.
[RFC5234]Crocker，D.和P.Overell，“语法规范的扩充BNF:ABNF”，STD 68，RFC 5234，2008年1月。
[RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information Reporting Using a Source Description (SDES) Item and an RTCP Extended Report (XR) Block", RFC 6776, October 2012.
[RFC6776]Clark，A.和Q.Wu，“使用源描述（SDES）项和RTCP扩展报告（XR）块的测量标识和信息报告”，RFC 6776，2012年10月。
[RFC6958] Clark, A., Zhang, S., Zhao, J., and Q. Wu, "RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap Loss Metric Reporting", RFC 6958, May 2013.
[RFC6958]Clark，A.，Zhang，S.，Zhao，J.，和Q.Wu，“用于突发/间隙损失度量报告的RTP控制协议（RTCP）扩展报告（XR）块”，RFC 6958，2013年5月。
[RFC7002] Clark, A., Zorn, G., and Q. Wu, "RTP Control Protocol (RTCP) Extended Report (XR) Block for Discard Count Metric Reporting", RFC 7002, September 2013.
[RFC7002]Clark，A.，Zorn，G.，和Q.Wu，“用于丢弃计数度量报告的RTP控制协议（RTCP）扩展报告（XR）块”，RFC 7002，2013年9月。
[RFC7003] Clark, A., Huang, R., and Q. Wu, Ed., "RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap Discard Metric Reporting", RFC 7003, September 2013.
[RFC7003]Clark，A.，Huang，R.，和Q.Wu，Ed.，“用于突发/间隙丢弃度量报告的RTP控制协议（RTCP）扩展报告（XR）块”，RFC 7003，2013年9月。
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New Performance Metric Development", BCP 170, RFC 6390, October 2011.
[RFC6390]Clark，A.和B.Claise，“考虑新性能指标开发的指南”，BCP 170，RFC 63902011年10月。
[RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design Considerations for Protocol Extensions", RFC 6709, September 2012.
[RFC6709]Carpenter，B.，Aboba，B.，和S.Cheshire，“协议扩展的设计考虑”，RFC 6709，2012年9月。
[RFC6792] Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the RTP Monitoring Framework", RFC 6792, November 2012.
[RFC6792]Wu，Q.，Hunt，G.，和P.Arden，“RTP监控框架的使用指南”，RFC 6792，2012年11月。
a. Burst Loss Rate Metric
a. 突发丢失率度量
* Metric Name: RTP Burst Loss Rate
* 指标名称：RTP突发丢失率
* Metric Description: The fraction of packets lost during bursts since the beginning of reception for RTP traffic.
* 度量描述：自RTP通信开始接收以来，在突发过程中丢失的数据包的分数。
* Method of Measurement or Calculation: See Section 3.1.2, Burst Loss Rate definition.
* 测量或计算方法：见第3.1.2节，突发损失率定义。
* Units of Measurement: See Section 3.1.2, Burst Loss Rate definition.
* 测量单位：见第3.1.2节，突发损失率定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.1, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.1节第2段。
* Measurement Timing: See Section 3.1, 1st paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量时间：测量时间见第3.1节第1段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
b. Gap Loss Rate Metric
b. 缺口损失率度量
* Metric Name: RTP Gap Loss Rate
* 指标名称：RTP间隙损失率
* Metric Description: The fraction of packets lost during gaps since the beginning of reception for RTP traffic.
* 度量描述：自RTP通信开始接收以来，在间隔期间丢失的数据包的分数。
* Method of Measurement or Calculation: See Section 3.1.2, Gap Loss Rate definition.
* 测量或计算方法：见第3.1.2节，间隙损失率定义。
* Units of Measurement: See Section 3.1.2, Gap Loss Rate definition.
* 计量单位：见第3.1.2节，间隙损失率定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.1, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.1节第2段。
* Measurement Timing: See Section 3.1, 1st paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量时间：测量时间见第3.1节第1段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
c. Burst Duration Mean Metric
c. 突发持续时间平均度量
* Metric Name: RTP Burst Duration Mean
* 指标名称：RTP突发持续时间平均值
* Metric Description: The mean duration of the burst periods that have occurred since the beginning of reception for RTP traffic.
* 度量说明：自RTP通信开始接收以来发生的突发周期的平均持续时间。
* Method of Measurement or Calculation: See Section 3.1.2, Burst Loss Rate definition.
* 测量或计算方法：见第3.1.2节，突发损失率定义。
* Units of Measurement: This metric is expressed in milliseconds.
* 度量单位：此度量单位以毫秒表示。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.1, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.1节第2段。
* Measurement Timing: See Section 3.1, 1st paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量时间：测量时间见第3.1节第1段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
d. Burst Duration Variance Metric
d. 突发持续时间方差度量
* Metric Name: RTP Burst Duration Variance
* 度量名称：RTP突发持续时间差异
* Metric Description: The variance duration of the burst periods that have occurred since the beginning of reception for RTP traffic.
* 度量说明：自RTP通信开始接收以来发生的突发周期的方差持续时间。
* Method of Measurement or Calculation: See Section 3.1.2, Burst Duration Variance definition.
* 测量或计算方法：见第3.1.2节，突发持续时间偏差定义。
* Units of Measurement: See Section 3.1.2, Burst Duration Variance definition.
* 计量单位：见第3.1.2节，突发持续时间差异定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.1, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.1节第2段。
* Measurement Timing: See Section 3.1, 1st paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量时间：测量时间见第3.1节第1段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
e. Burst Discard Rate Metric
e. 突发丢弃率度量
* Metric Name: RTP Burst Discard Rate
* 指标名称：RTP突发丢弃率
* Metric Description: The fraction of packets discarded during bursts since the beginning of reception for RTP traffic.
* 度量描述：自RTP通信开始接收以来，在突发期间丢弃的数据包的分数。
* Method of Measurement or Calculation: See Section 3.2.2, Burst Discard Rate definition.
* 测量或计算方法：见第3.2.2节，突发丢弃率定义。
* Units of Measurement: See Section 3.2.2, Burst Discard Rate definition.
* 测量单位：见第3.2.2节，突发丢弃率定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.2, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.2节第2段。
* Measurement Timing: See Section 3.2, 3rd paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量定时：测量定时见第3.2节第3段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
f. Gap Discard Rate Metric
f. 缺口丢弃率度量
* Metric Name: RTP Gap Discard Rate
* 指标名称：RTP差距丢弃率
* Metric Description: The fraction of packets discarded during gaps since the beginning of reception for RTP traffic.
* 度量描述：自RTP通信开始接收以来，在间隔期间丢弃的数据包的分数。
* Method of Measurement or Calculation: See Section 3.2.2, Gap Discard Rate definition.
* 测量或计算方法：见第3.2.2节，间隙报废率定义。
* Units of Measurement: See Section 3.2.2, Gap Discard Rate definition.
* 测量单位：见第3.2.2节，间隙报废率定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3.2, 2nd paragraph.
* 具有潜在测量域的测量点：见第3.2节第2段。
* Measurement Timing: See Section 3.2, 3rd paragraph for measurement timing and Section 3.1.2 for Interval Metric flag.
* 测量定时：测量定时见第3.2节第3段，间隔公制标志见第3.1.2节。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
g. Number of Discarded Frames Metric
g. 丢弃帧数度量
* Metric Name: Number of discarded frames in RTP
* 度量名称：RTP中丢弃的帧数
* Metric Description: Number of frames discarded in a certain sequence number interval for RTP traffic.
* 度量描述：RTP通信在特定序列号间隔内丢弃的帧数。
* Method of Measurement or Calculation: See Section 4.1.2, Number of discarded frames definition. This metric is directly measured and can be inferred from packet(s) that comprise the frame.
* 测量或计算方法：见第4.1.2节，丢弃帧数定义。该度量是直接测量的，并且可以从组成帧的数据包中推断出来。
* Units of Measurement: This metric is expressed as a 32-bit unsigned integer value.
* 度量单位：此度量以32位无符号整数值表示。
* Measurement Point(s) with Potential Measurement Domain: See Section 4.1, 1st paragraph.
* 具有潜在测量域的测量点：见第4.1节第1段。
* Measurement Timing: See Section 4.1, Number of discarded frames definition. This metric relies on the sequence number interval and RTCP RR packet of [RFC3550] to determine measurement timing.
* 测量定时：见第4.1节，丢弃帧数定义。该度量依赖于序列号间隔和[RFC3550]的RTCP RR数据包来确定测量定时。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
h. Number of Duplicate Frames Metric
h. 重复帧数度量
* Metric Name: Number of duplicate frames in RTP
* 度量名称：RTP中的重复帧数
* Metric Description: Number of frames duplicated in a certain sequence number interval for RTP traffic.
* 度量描述：RTP流量在特定序列号间隔内复制的帧数。
* Method of Measurement or Calculation: See Section 4.1.2, Number of duplicate frames definition. This metric is directly measured and can be inferred from packet(s) that comprise the frame.
* 测量或计算方法：见第4.1.2节，重复帧数定义。该度量是直接测量的，并且可以从组成帧的数据包中推断出来。
* Units of Measurement: This metric is expressed as a 32-bit unsigned integer value.
* 度量单位：此度量以32位无符号整数值表示。
* Measurement Point(s) with Potential Measurement Domain: See Section 4.1, 1st paragraph.
* 具有潜在测量域的测量点：见第4.1节第1段。
* Measurement Timing: See Section 4.1, Number of duplicate frames definition. This metric relies on the sequence number interval to determine measurement timing.
* 测量时间：见第4.1节，重复帧数定义。该度量依赖于序列号间隔来确定测量定时。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
i. Number of Full Lost Frames Metric
i. 完全丢失帧数度量
* Metric Name: Number of full lost frames in RTP
* 度量名称：RTP中完全丢失的帧数
* Metric Description: A frame is either split across multiple RTP packets or carried in only one RTP packet. If the whole frame or all the packets of the frame is lost, this frame is regarded as one full_lost_frame.
* 度量描述：一个帧可以在多个RTP数据包中分割，也可以仅在一个RTP数据包中携带。如果整个帧或该帧的所有数据包丢失，则该帧被视为一个完整的丢失帧。
* Method of Measurement or Calculation: See Section 4.1.2, Number of full lost frames definition.
* 测量或计算方法：见第4.1.2节，完全丢失帧数定义。
* Units of Measurement: This metric is expressed as a 32-bit unsigned integer value.
* 度量单位：此度量以32位无符号整数值表示。
* Measurement Point(s) with Potential Measurement Domain: See Section 4.1, 1st paragraph.
* 具有潜在测量域的测量点：见第4.1节第1段。
* Measurement Timing: See Section 4.1, Number of full lost frames definition. This metric relies on the sequence number interval to determine measurement timing.
* 测量定时：见第4.1节，完全丢失帧数定义。该度量依赖于序列号间隔来确定测量定时。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
j. Number of Partial Lost Frames Metric
j. 部分丢失帧数度量
* Metric Name: Number of partial lost frames in RTP
* 度量名称：RTP中部分丢失的帧数
* Metric Description: When a frame is split across multiple RTP packets and some RTP packets of the frame are lost, this frame is regarded as one partial_lost_frame.
* 度量描述：当一个帧被分割成多个RTP数据包，并且该帧的一些RTP数据包丢失时，该帧被视为一个部分丢失的帧。
* Method of Measurement or Calculation: See Section 4.1.2, Number of partial lost frames definition.
* 测量或计算方法：见第4.1.2节，部分丢失帧数定义。
* Units of Measurement: This metric is expressed as a 32-bit unsigned integer value.
* 度量单位：此度量以32位无符号整数值表示。
* Measurement Point(s) with Potential Measurement Domain: See Section 4.1, 1st paragraph.
* 具有潜在测量域的测量点：见第4.1节第1段。
* Measurement Timing: See Section 4.1, Number of partial lost frames definition. This metric relies on the sequence number interval to determine measurement timing.
* 测量时间：见第4.1节，部分丢失帧数定义。该度量依赖于序列号间隔来确定测量定时。
* Use and Applications: See Section 1.4.
* 用途和应用：见第1.4节。
* Reporting Model: See RFC 3611.
* 报告模式：见RFC 3611。
Authors' Addresses
作者地址
Glen Zorn Network Zen 227/358 Thanon Sanphawut Bang Na, Bangkok 10260 Thailand
格伦佐恩网络禅宗227/358泰国曼谷Thanon Sanphawut Bang Na 10260
Phone: +66 (0) 909-201060
EMail: glenzorn@gmail.com
Phone: +66 (0) 909-201060
EMail: glenzorn@gmail.com
Roland Schott Deutsche Telekom Deutsche-Telekom-Allee 7 Darmstadt 64295 Germany
罗兰·肖特德国电信德国电信阿莱7号达姆施塔特64295德国
EMail: Roland.Schott@telekom.de
EMail: Roland.Schott@telekom.de
Qin Wu (editor) Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China
秦武（编辑）中国江苏省南京市雨花区华为软件大道101号210012
EMail: sunseawq@huawei.com
EMail: sunseawq@huawei.com
Rachel Huang Huawei 101 Software Avenue, Yuhua District Nanjing 210012 China
中国南京市雨花区华为软件大道101号，邮编：210012
EMail: Rachel@huawei.com
EMail: Rachel@huawei.com