Internet Engineering Task Force (IETF) R. Huang
Request for Comments: 6990 Q. Wu
Category: Standards Track Huawei
ISSN: 2070-1721 H. Asaeda
NICT
G. Zorn
Network Zen
August 2013
Internet Engineering Task Force (IETF) R. Huang
Request for Comments: 6990 Q. Wu
Category: Standards Track Huawei
ISSN: 2070-1721 H. Asaeda
NICT
G. Zorn
Network Zen
August 2013
RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG-2 Transport Stream (TS) Program Specific Information (PSI) Independent Decodability Statistics Metrics Reporting
用于MPEG-2传输流（TS）节目特定信息（PSI）独立可解码性统计指标报告的RTP控制协议（RTCP）扩展报告（XR）块
Abstract
摘要
An MPEG-2 Transport Stream (TS) is a standard container format used in the transmission and storage of multimedia data. Unicast/ multicast MPEG-2 TS over RTP is widely deployed in IPTV systems. This document defines an RTP Control Protocol (RTCP) Extended Report (XR) block that allows the reporting of MPEG-2 TS decodability statistics metrics related to transmissions of MPEG-2 TS over RTP. The metrics specified in the RTCP XR block are not dependent on Program Specific Information (PSI) carried in MPEG-2 TS.
MPEG-2传输流（TS）是用于多媒体数据传输和存储的标准容器格式。RTP上的单播/多播MPEG-2 TS广泛部署在IPTV系统中。本文档定义了一个RTP控制协议（RTCP）扩展报告（XR）块，该块允许报告与通过RTP传输MPEG-2 TS相关的MPEG-2 TS可解码性统计指标。RTCP XR块中指定的度量不依赖于MPEG-2 TS中携带的节目特定信息（PSI）。
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/rfc6990.
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/rfc6990.
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 . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. MPEG-2 Transport Stream Decodability Metrics . . . . . . 3
1.2. RTCP and RTCP Extended Reports . . . . . . . . . . . . . 3
1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3
1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2. Standards Language . . . . . . . . . . . . . . . . . . . . . 4
3. MPEG-2 TS PSI-Independent Decodability Statistics Metrics
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. SDP rtcp-xr Attribute Extension . . . . . . . . . . . . . 8
4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 8
5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9
5.3. Contact Information for Registrations . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 10
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. MPEG-2 Transport Stream Decodability Metrics . . . . . . 3
1.2. RTCP and RTCP Extended Reports . . . . . . . . . . . . . 3
1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3
1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 4
2. Standards Language . . . . . . . . . . . . . . . . . . . . . 4
3. MPEG-2 TS PSI-Independent Decodability Statistics Metrics
Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 8
4.1. SDP rtcp-xr Attribute Extension . . . . . . . . . . . . . 8
4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 8
5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9
5.3. Contact Information for Registrations . . . . . . . . . . 9
6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . 10
The European Telecommunications Standards Institute (ETSI) has defined a set of syntax and information consistency tests and corresponding indicators [ETSI] that are recommended for the monitoring of MPEG-2 Transport Streams [ISO-IEC.13818-1.2013]. The tests and corresponding indicators are grouped according to priority:
欧洲电信标准协会（ETSI）定义了一套语法和信息一致性测试以及相应的指标[ETSI]，建议用于监测MPEG-2传输流[ISO-IEC.13818-1.2013]。测试和相应的指标根据优先级进行分组：
o First priority - Necessary for decodability (basic monitoring)
o 第一优先级-可分解性所需（基本监测）
o Second priority - Recommended for continuous or periodic monitoring
o 第二优先级-建议用于连续或定期监测
o Third priority - Recommended for application-dependent monitoring
o 第三优先级-建议用于依赖于应用程序的监视
This memo is based on information consistency tests and resulting indicators defined by ETSI [ETSI] and defines a new block type to augment those defined in [RFC3611] for use with MPEG-2 Transport Stream (TS) [ISO-IEC.13818-1.2013]. The new block type supports reporting of the number of occurrences of each PSI-independent indicator in the first and second priorities; third priority indicators are not supported.
本备忘录基于ETSI[ETSI]定义的信息一致性测试和结果指标，并定义了一种新的块类型，以扩充[RFC3611]中定义的用于MPEG-2传输流（TS）[ISO-IEC.13818-1.2013]的块类型。新的块类型支持报告第一和第二优先级中每个PSI独立指示器的出现次数；不支持第三优先级指标。
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]。
"Guidelines for Considering New Performance Metric Development" [RFC6390] provides guidance on the definition and specification of performance metrics. "Guidelines for Use of the RTP Monitoring Framework" [RFC6792] provides guidance on the reporting block format using RTCP XR. The new report block described in this memo is in compliance with the monitoring architecture specified in [RFC6792] and the performance metrics framework [RFC6390].
“考虑制定新绩效指标的指南”[RFC6390]提供了关于绩效指标定义和规范的指南。“RTP监控框架使用指南”[RFC6792]提供了使用RTCP XR的报告块格式指南。本备忘录中描述的新报告块符合[RFC6792]和性能度量框架[RFC6390]中规定的监控体系结构。
This block type allows a count of MPEG-2 Transport Stream quality metrics that are measured in accordance with ETSI TR 101290 [ETSI] to be reported by an endpoint. These metrics are useful for identifying bitstream packetization and transport stream encoding problems that may affect the user's perception of a video service delivered over RTP.
该块类型允许端点报告根据ETSI TR 101290[ETSI]测量的MPEG-2传输流质量度量的计数。这些度量对于识别可能影响用户对通过RTP交付的视频服务的感知的比特流分组和传输流编码问题是有用的。
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。
ETSI TR 101290 [ETSI] generally defines metrics related to error events while this document contains counts of those metrics defined in [ETSI]. The block defined in this document reports MPEG-2 TS PSI-independent decodability statistics metrics beyond the information carried in the standard RTCP packet format, which are measured at the receiving end of the RTP stream. It contains counts of eight metrics defined in ETSI TR 101290 [ETSI]. Information is reported about basic monitoring parameters necessary to ensure that the TS can be decoded, including:
ETSI TR 101290[ETSI]通常定义与错误事件相关的度量，而本文档包含[ETSI]中定义的那些度量的计数。本文档中定义的块报告了MPEG-2 TS PSI独立可解码性统计指标，这些指标超出了标准RTCP数据包格式中携带的信息，在RTP流的接收端进行测量。它包含ETSI TR 101290[ETSI]中定义的八个度量的计数。报告了确保TS可解码所需的基本监测参数信息，包括：
o Transport Stream Synchronization Losses
o 传输流同步损失
o Sync byte errors
o 同步字节错误
o Continuity count errors
o 连续性计数错误
and continuous monitoring parameters necessary to ensure the continuous decoding, including:
以及确保连续解码所需的连续监测参数，包括：
o Transport errors
o 传输错误
o Program Clock Reference (PCR) errors
o 程序时钟参考（PCR）错误
o PCR repetition errors
o PCR重复错误
o PCR discontinuity indicator errors
o PCR不连续指示符错误
o PCR accuracy errors
o PCR准确度误差
o Presentation Time Stamp (PTS) errors
o 演示文稿时间戳（PTS）错误
The other parameters are ignored since they do not apply to all MPEG-2 implementations. For further information on these parameters, see [ETSI]. Note that when the report of this block spans across more than one measurement interval [RFC6776], the count of the metrics (e.g., Sync byte errors and PCR errors) defined in [ETSI] may reflect a problem in the current or previous measurement interval.
其他参数被忽略，因为它们不适用于所有MPEG-2实现。有关这些参数的更多信息，请参见[ETSI]。请注意，当此块的报告跨越多个测量间隔[RFC6776]时，[ETSI]中定义的度量计数（例如，同步字节错误和PCR错误）可能反映当前或以前测量间隔中的问题。
The MPEG-2 TS PSI-Independent Decodability Statistics Metrics Block has the following format:
MPEG-2 TS PSI独立可解码性统计度量块具有以下格式：
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=22 | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| begin_seq | end_seq |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TS_sync_loss_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sync_byte_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Continuity_count_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transport_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_repetition_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_discontinuity_indicator_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_accuracy_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PTS_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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=22 | Reserved | Block Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| begin_seq | end_seq |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TS_sync_loss_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sync_byte_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Continuity_count_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Transport_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_repetition_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_discontinuity_indicator_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PCR_accuracy_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PTS_error_count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Block Type (BT): 8 bits
块类型（BT）：8位
The MPEG-2 TS PSI-Independent Decodability Statistics Metrics Block is identified by the constant 22.
MPEG-2 TS PSI独立的可解码性统计度量块由常数22标识。
Reserved: 8 bits
保留：8位
These bits are reserved. They MUST be set to zero by senders and ignored by receivers (see [RFC6709] Section 4.2).
这些位是保留的。发送方必须将其设置为零，接收方必须忽略（见[RFC6709]第4.2节）。
Block Length: 16 bits
块长度：16位
The constant 11, in accordance with the definition of this field in Section 3 of RFC 3611. The block MUST be discarded if the block length is set to a different value.
常数11，符合RFC 3611第3节中该字段的定义。如果块长度设置为不同的值，则必须丢弃该块。
Synchronization source (SSRC) of Source: 32 bits
源的同步源（SSRC）：32位
As defined in Section 4.1 of RFC 3611.
如RFC 3611第4.1节所定义。
begin_seq: 16 bits
开始顺序：16位
The RTP sequence number corresponding to the start of the measurement period, as defined in Section 4.1 of RFC 3611.
RFC 3611第4.1节中定义的与测量周期开始对应的RTP序列号。
end_seq: 16 bits
结束顺序：16位
The RTP sequence number corresponding to the end of the measurement period, as defined in Section 4.1 of RFC 3611.
RFC 3611第4.1节中定义的与测量周期结束对应的RTP序列号。
TS_sync_loss_count: 32 bits
同步丢失计数：32位
A count of the number of TS_sync_loss errors that occurred in the above sequence number interval. A TS_sync_loss error occurs when there are two or more consecutive incorrect sync bytes within the MPEG-2 TS, as defined in Section 5.2.1 of [ETSI].
在上述序列号间隔内发生的TS_sync_丢失错误数的计数。如[ETSI]第5.2.1节所定义，当MPEG-2 TS中存在两个或更多连续的不正确同步字节时，会发生TS_sync_丢失错误。
Sync_byte_error_count: 32 bits
同步字节错误计数：32位
A count of the number of Sync_byte_errors that occurred in the above sequence number interval. A sync byte error occurs when the sync byte is not equal to 0x47 in any TS packet contained in the MPEG-2 TS, as defined in Section 5.2.1 of [ETSI].
在上述序列号间隔内发生的同步字节错误数的计数。当同步字节不等于[ETSI]第5.2.1节中定义的MPEG-2 TS中包含的任何TS数据包中的0x47时，会发生同步字节错误。
Continuity_count_error_count: 32 bits
连续性\u计数\u错误\u计数：32位
A count of the number of Continuity_count_errors that occurred in the above sequence number interval. A Continuity_count_error occurs when any of the following faults happen within the MPEG-2 TS -- incorrect packet order, a packet occurs more than twice, or a packet is lost, as defined in Section 5.2.1 of [ETSI].
在上述序列号间隔内发生的连续性\u计数\u错误数的计数。如[ETSI]第5.2.1节所定义，当MPEG-2 TS内发生以下任何故障时，即发生连续性计数错误——数据包顺序错误、数据包出现两次以上或数据包丢失。
Transport_error_count: 32 bits
传输错误计数：32位
A count of the number of Transport_errors that occurred in the above sequence number interval. A Transport_error occurs when an erroneous TS packet cannot be corrected within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI].
在上述序列号间隔内发生的传输错误数的计数。如[ETSI]第5.2.2节所定义，当错误的TS数据包无法在MPEG-2 TS内纠正时，会发生传输错误。
PCR_error_count: 32 bits
PCR\u错误\u计数：32位
A count of the number of PCR_errors that occurred in the above sequence number interval. A PCR_error occurs if the primary clock reference (PCR) is not seen for more than 100 ms within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI]. The time interval between two consecutive PCR values should be no more than 40 ms.
在上述序列号间隔内发生的PCR_错误数的计数。如[ETSI]第5.2.2节中所定义，如果在MPEG-2 TS内未看到主时钟参考（PCR）超过100 ms，则会发生PCR_错误。两个连续PCR值之间的时间间隔不得超过40 ms。
PCR_repetition_error_count: 32 bits
PCR\u重复\u错误\u计数：32位
A count of the number of PCR_repetition_errors that occurred in the above sequence number interval. A PCR_repetition_error occurs when the time interval between two consecutive PCR values is more than 40 ms within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI].
在上述序列号间隔内发生的PCR_重复_错误数的计数。如[ETSI]第5.2.2节所定义，当MPEG-2 TS内两个连续PCR值之间的时间间隔超过40 ms时，会发生PCR_重复_错误。
PCR_discontinuity_indicator_error_count: 32 bits
PCR不连续性指示器错误计数：32位
A count of the number of PCR_discontinuity_indicator_errors that occurred in the above sequence number interval. A PCR_discontinuity_indicator_error occurs if the time interval between two consecutive PCR values is more than 100 ms within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI].
在上述序列号间隔内发生的PCR_不连续性_指示器_错误数的计数。如[ETSI]第5.2.2节所定义，如果MPEG-2 TS内两个连续PCR值之间的时间间隔超过100 ms，则会发生PCR不连续性指示器错误。
PCR_accuracy_error_count: 32 bits
PCR\u精度\u错误\u计数：32位
A count of the number of PCR_accuracy_errors that occurred in the above sequence number interval. A PCR_accuracy_error occurs when the PCR accuracy of the selected program is outside the range of +/-500 ns within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI].
在上述序列号间隔内发生的PCR\u准确性\u错误数的计数。如[ETSI]第5.2.2节所定义，当选定节目的PCR精确度超出MPEG-2 TS内+/-500 ns的范围时，会发生PCR精确度错误。
PTS_error_count: 32 bits
PTS_错误_计数：32位
A count of the number of PTS_errors that occurred in the above sequence number interval. A PTS_error occurs when the PTS repetition is more than 700 ms within the MPEG-2 TS, as defined in Section 5.2.2 of [ETSI]. Note that the PTS is contained in the MPEG-2 TS and is used to aid the decoder in presenting the program on time, at the correct speed, and synchronized.
在上述序列号间隔内发生的PTS_错误数的计数。如[ETSI]第5.2.2节所定义，当PTS重复在MPEG-2 TS内超过700 ms时，会发生PTS_错误。注意，PTS包含在MPEG-2ts中，并且用于帮助解码器以正确的速度按时呈现节目并进行同步。
RFC 3611 defines the use of the Session Description Protocol (SDP) [RFC4566] for signaling the use of RTCP XR blocks. However, XR blocks MAY be used without prior signaling (see Section 5 of RFC 3611).
RFC 3611定义了会话描述协议（SDP）[RFC4566]的使用，用于向RTCP XR块的使用发送信号。然而，可以在没有事先信令的情况下使用XR块（参见RFC 3611的第5节）。
This session augments the SDP attribute "rtcp-xr" defined in Section 5.1 of RFC 3611 by providing an additional value of "xr-format" to signal the use of the report block defined in this document. The ABNF [RFC5234] syntax is as follows.
此会话通过提供附加值“xr format”来表示使用本文档中定义的报告块，从而增强RFC 3611第5.1节中定义的SDP属性“rtcp xr”。ABNF[RFC5234]语法如下所示。
xr-format =/ xr-tpid-block
xr format=/xr tpid块
xr-tpid-block = "ts-psi-indep-decodability"
xr tpid block=“ts psi不可分解性”
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 parameters, 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。有关单边参数的报价/应答的详细用法，请参阅[RFC3611]第5.2节。
New report block types for RTCP XR are subject to IANA registration. For general guidelines on IANA allocations for RTCP XR, refer to Section 6.2 of RFC 3611.
RTCP XR的新报告块类型需要IANA注册。有关RTCP XR IANA分配的一般指南，请参阅RFC 3611第6.2节。
This document assigns the block type value 22 in the IANA "RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry" to the "MPEG-2 Transport Stream PSI-Independent Decodability Statistics Metrics Block".
本文档将IANA“RTP控制协议扩展报告（RTCP XR）块类型注册表”中的块类型值22分配给“MPEG-2传输流PSI独立可解码性统计指标块”。
This document also registers the new parameter "ts-psi-indep-decodability" in the "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry".
本文档还在“RTP控制协议扩展报告（RTCP XR）会话描述协议（SDP）参数注册表”中注册新参数“ts psi indep decodability”。
The contact information for 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
There might be some relationship between reported error counters and contractual Service Level Agreements (SLAs); hence, an attack (e.g., RTP endpoints reporting false data, or an attacker in the path modifying the data being reported) might deliberately corrupt these error counters, resulting in financial implications for the network operator (either as a result of unneeded performance metrics, or penalty charges for SLA failure).
报告的错误计数器和合同服务水平协议（SLA）之间可能存在某种关系；因此，攻击（例如，RTP端点报告错误数据，或路径中的攻击者修改报告的数据）可能会故意损坏这些错误计数器，从而对网络运营商造成财务影响（可能是由于不必要的性能指标，或SLA故障的罚款）。
A solution to prevent such an attack is to apply an authentication and integrity protection framework for the RTCP XR block. This can be accomplished using the RTP profile that combines Secure RTP [RFC3711] and the Audio-Visual Profile with Feedback (AVPF) into Secure AVPF (SAVPF) [RFC5124].
防止此类攻击的解决方案是为RTCP XR块应用身份验证和完整性保护框架。这可以通过使用RTP配置文件来实现，RTP配置文件将安全RTP[RFC3711]和带反馈的视听配置文件（AVPF）组合成安全AVPF（SAVPF）[RFC5124]。
Besides this, the RTCP XR block in this document introduces no new security considerations beyond those described in [RFC3611].
除此之外，本文档中的RTCP XR块除了[RFC3611]中描述的安全注意事项外，没有引入任何新的安全注意事项。
Thanks to Ray van Brandenburg, Claire Bi, Colin Perkins, Roni Even, Dan Romascanu, Ali Begen, Alexey Melnikov, Bert Wijnen, Gonzalo Camarillo, Benoit Claise, and Alan Clark for useful reviews and suggestions.
感谢Ray van Brandenburg、Claire Bi、Colin Perkins、Roni Even、Dan Romascanu、Ali Begen、Alexey Melnikov、Bert Wijnen、Gonzalo Camarillo、Benoit Claise和Alan Clark提供了有用的评论和建议。
[ETSI] ETSI, "Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems", Technical Report TR 101 290, 2001.
[ETSI]ETSI，“数字视频广播（DVB）；DVB系统的测量指南”，技术报告TR 101 290，2001年。
[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。
[RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, "The Secure Real-time Transport Protocol (SRTP)", RFC 3711, March 2004.
[RFC3711]Baugher，M.，McGrew，D.，Naslund，M.，Carrara，E.，和K.Norrman，“安全实时传输协议（SRTP）”，RFC 37112004年3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。
[RFC5124] Ott, J. and E. Carrara, "Extended Secure RTP Profile for Real-time Transport Control Protocol (RTCP)-Based Feedback (RTP/SAVPF)", RFC 5124, February 2008.
[RFC5124]Ott，J.和E.Carrara，“基于实时传输控制协议（RTCP）的反馈扩展安全RTP配置文件（RTP/SAVPF）”，RFC 51242008年2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。
[ISO-IEC.13818-1.2013] International Organization for Standardization, "Information technology - Generic coding of moving pictures and associated audio information: Systems", ISO International Standard 13818-1, May 2013.
[ISO-IEC.13818-1.2013]国际标准化组织，“信息技术-运动图像和相关音频信息的通用编码：系统”，ISO国际标准13818-1，2013年5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。
[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。
[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。
Authors' Addresses
作者地址
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.huang@huawei.com
EMail: rachel.huang@huawei.com
Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China
中国江苏省南京市雨花区华为软件大道101号秦武210012
EMail: bill.wu@huawei.com
EMail: bill.wu@huawei.com
Hitoshi Asaeda National Institute of Information and Communications Technology 4-2-1 Nukui-Kitamachi Koganei, Tokyo 184-8795 Japan
浅田仁国立信息与通信技术研究所4-2-1日本东京北天町小江内Nukui Kitamachi Koganei 184-8795
EMail: asaeda@nict.go.jp
EMail: asaeda@nict.go.jp
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) 8-1000-4155
EMail: glenzorn@gmail.com
Phone: +66 (0) 8-1000-4155
EMail: glenzorn@gmail.com