Internet Engineering Task Force (IETF) A. Clark
Request for Comments: 7002 Telchemy
Category: Standards Track G. Zorn
ISSN: 2070-1721 Network Zen
Q. Wu
Huawei
September 2013
Internet Engineering Task Force (IETF) A. Clark
Request for Comments: 7002 Telchemy
Category: Standards Track G. Zorn
ISSN: 2070-1721 Network Zen
Q. Wu
Huawei
September 2013
RTP Control Protocol (RTCP) Extended Report (XR) Block for Discard Count Metric Reporting
用于丢弃计数度量报告的RTP控制协议（RTCP）扩展报告（XR）块
Abstract
摘要
This document defines an RTP Control Protocol (RTCP) Extended Report (XR) block that allows the reporting of a simple discard count metric for use in a range of RTP applications.
本文档定义了一个RTP控制协议（RTCP）扩展报告（XR）块，该块允许报告一个简单的丢弃计数指标，以便在一系列RTP应用程序中使用。
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/rfc7002.
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/rfc7002.
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. Discard Count Report Block . . . . . . . . . . . . . . . 2
1.2. RTCP and RTCP Extended Reports . . . . . . . . . . . . . 3
1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3
1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Discard Count Metrics Block . . . . . . . . . . . . . . . . . 4
3.1. Report Block Structure . . . . . . . . . . . . . . . . . 5
3.2. Definition of Fields in the Discard Count Metrics Block . 5
4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. SDP rtcp-xr Attribute Extension . . . . . . . . . . . . . 7
4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
5.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 8
5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 8
5.3. Contact Information for Registrations . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
9.1. Normative References . . . . . . . . . . . . . . . . . . 9
9.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Metrics Represented Using the Template from RFC 6390 11
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Discard Count Report Block . . . . . . . . . . . . . . . 2
1.2. RTCP and RTCP Extended Reports . . . . . . . . . . . . . 3
1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3
1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Discard Count Metrics Block . . . . . . . . . . . . . . . . . 4
3.1. Report Block Structure . . . . . . . . . . . . . . . . . 5
3.2. Definition of Fields in the Discard Count Metrics Block . 5
4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 7
4.1. SDP rtcp-xr Attribute Extension . . . . . . . . . . . . . 7
4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . 7
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
5.1. New RTCP XR Block Type Value . . . . . . . . . . . . . . 8
5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 8
5.3. Contact Information for Registrations . . . . . . . . . . 8
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
9.1. Normative References . . . . . . . . . . . . . . . . . . 9
9.2. Informative References . . . . . . . . . . . . . . . . . 10
Appendix A. Metrics Represented Using the Template from RFC 6390 11
This document defines a new block type to augment those defined in [RFC3611] for use in a range of RTP applications. The new block type supports the reporting of the number of packets that are received correctly but are never played out, typically because they arrive too late (buffer underflow) or too early (buffer overflow) to be played out. The metric is applicable both to systems that use packet loss repair techniques (such as forward error correction [RFC5109] or retransmission [RFC4588]) and to those that do not.
本文件定义了一种新的块类型，以扩充[RFC3611]中定义的块类型，以便在一系列RTP应用中使用。新的块类型支持报告正确接收但从未播放的数据包数量，通常是因为数据包到达太晚（缓冲区下溢）或太早（缓冲区溢出）而无法播放。该度量既适用于使用分组丢失修复技术（例如前向纠错[RFC5109]或重传[RFC4588]）的系统，也适用于不使用分组丢失修复技术的系统。
This metric is useful for identifying the existence, and characterizing the severity, of packet transport problems that may affect users' perceptions of a service delivered over RTP.
此度量对于识别分组传输问题的存在和表征其严重性非常有用，这些问题可能会影响用户对通过RTP交付的服务的感知。
This block may be used in conjunction with [RFC7003], which provides additional information on the pattern of discarded packets. However, the metric in [RFC7003] may be used independently of the metrics in this block.
该块可与[RFC7003]结合使用，后者提供关于丢弃包模式的附加信息。然而，[RFC7003]中的度量可以独立于该块中的度量使用。
When a Discard Count Metrics Block is sent together with a Burst/Gap Discard Metrics Block (defined in [RFC7003]) to the media sender or RTP-based network management system, the information carried in the Discard Count Metrics Block and the Burst/Gap Discard Metrics Block allows systems receiving the blocks to calculate burst/gap summary statistics (e.g., the gap discard rate).
当丢弃计数度量块与突发/间隙丢弃度量块（在[RFC7003]中定义）一起发送到媒体发送方或基于RTP的网络管理系统时，丢弃计数度量块和突发/间隙丢弃度量块中携带的信息允许接收块的系统计算突发/间隙汇总统计信息（例如，间隙丢弃率）。
The metric belongs to the class of transport-related end-system metrics defined in [RFC6792].
该指标属于[RFC6792]中定义的与传输相关的终端系统指标类别。
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]。
"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 for reporting block format using RTCP XR. The metrics block described in this document is in accordance with the guidelines in [RFC6390] and [RFC6792].
“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报告块格式的指南。本文件中描述的度量块符合[RFC6390]和[RFC6792]中的指南。
This metric is believed to be applicable to a large class of RTP applications that use a de-jitter buffer [RFC5481].
该指标被认为适用于使用去抖动缓冲器[RFC5481]的一大类RTP应用程序。
Discards due to late or early arriving packets affect user experience. The reporting of discards alerts senders and other receivers to the need to adjust their transmission or reception strategies. The reports allow network managers to diagnose these user experience problems.
由于数据包延迟或提前到达而导致的丢弃会影响用户体验。丢弃的报告提醒发送方和其他接收方需要调整其传输或接收策略。这些报告允许网络管理员诊断这些用户体验问题。
The ability to detect duplicate packets can be used by managers to detect network layer or sender behavior, which may indicate network or device issues. Based on the reports, these issues may be addressed prior to any impact on user experience.
管理者可以使用检测重复数据包的能力来检测网络层或发送者行为，这可能表示网络或设备问题。根据报告，这些问题可能会在对用户体验产生任何影响之前得到解决。
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 terms are defined:
此外，定义了以下术语：
Received, Lost, and Discarded
接收、丢失和丢弃
A packet shall be regarded as lost if it fails to arrive within an implementation-specific time window. A packet that arrives within this time window but is either too early or too late to be played out or is thrown away before playout due to packet duplication or redundancy shall be regarded as discarded. A packet shall not be regarded as discarded if it arrives within this time window but is dropped during decoding by some higher layer decoder, e.g., due to a decoding error. A packet shall be classified as one of the following: received (or OK), discarded, or lost. The discard count metric counts only discarded packets. The metric "cumulative number of packets lost" defined in [RFC3550] reports a count of packets lost from the media stream (single synchronization source (SSRC) within a single RTP session). Similarly, the metric "number of packets discarded" reports a count of packets discarded from the media stream (single SSRC within a single RTP session) arriving at the receiver. Another metric defined in [RFC5725] is available to report on packets that are not recovered by any repair techniques that may be in use.
如果数据包未能在特定于实现的时间窗口内到达，则该数据包应视为丢失。在该时间窗口内到达但由于数据包重复或冗余而太早或太迟无法播放或在播放前丢弃的数据包应视为丢弃。如果数据包在此时间窗口内到达，但在某个更高层解码器解码期间（例如，由于解码错误）被丢弃，则该数据包不应被视为丢弃。数据包应分类为以下类别之一：接收（或正常）、丢弃或丢失。丢弃计数度量仅统计丢弃的数据包。[RFC3550]中定义的度量“累计丢失的数据包数”报告从媒体流（单个RTP会话中的单个同步源（SSRC））丢失的数据包计数。类似地，度量“丢弃的分组数”报告从到达接收器的媒体流（单个RTP会话内的单个SSRC）丢弃的分组的计数。[RFC5725]中定义的另一个度量可用于报告可能使用的任何修复技术都无法恢复的数据包。
Metrics in this block report on the number of packets discarded in the stream arriving at the RTP end system. The measurement of these metrics is made at the receiving end of the RTP stream. Instances of this metrics block use the 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 interval in the Measurement Information Block indicating the span of the report and MUST be sent in the same compound RTCP packet as the Measurement Information Block. If the measurement interval is not received in the same compound RTCP packet as this metrics block, this metrics block MUST be discarded.
此块中的度量报告到达RTP端系统的流中丢弃的数据包数量。这些度量的测量在RTP流的接收端进行。此度量块的实例使用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间隔，并且必须在与度量信息块相同的复合RTCP数据包中发送。如果在与此度量块相同的复合RTCP数据包中未接收到测量间隔，则必须丢弃此度量块。
The structure of the Discard Count Metrics Block is as follows.
丢弃计数度量块的结构如下所示。
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=24 | I |DT | resv | Block Length = 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discard 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=24 | I |DT | resv | Block Length = 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of Source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Discard Count |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: Report Block Structure
图1：报告块结构
Block Type (BT): 8 bits
块类型（BT）：8位
A Discard Count Metrics Block is identified by the constant 24.
丢弃计数度量块由常数24标识。
Interval Metric flag (I): 2 bits
间隔度量标志（I）：2位
This field indicates whether the reported metric is an Interval, Cumulative, or Sampled metric [RFC6792]:
此字段指示报告的度量是间隔度量、累积度量还是采样度量[RFC6792]：
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 discard count metric can only be measured over definite intervals and cannot be sampled. Accordingly, the value I=01, indicating a sampled value, MUST NOT be sent, and MUST be discarded when received. In addition, the value I=00 is reserved and also MUST NOT be sent, and MUST be discarded when received.
在本文件中，报废计数指标只能在确定的时间间隔内测量，不能取样。因此，指示采样值的值I＝01不能被发送，并且在接收时必须被丢弃。此外，值I=00是保留的，也不得发送，并且在接收时必须丢弃。
Discard Type (DT): 2 bits
丢弃类型（DT）：2位
This field is used to identify the discard type used in this report block. The discard type is defined as follows:
此字段用于标识此报告块中使用的丢弃类型。丢弃类型定义如下：
00: Report packet discarded or being thrown away before playout due to packet duplication.
00：由于数据包重复，报告数据包在播放前被丢弃或丢弃。
01: Report packet discarded due to too early to be played out.
01：由于太早无法播放，报告包被丢弃。
10: Report packet discarded due to too late to be played out.
10：由于太晚无法播放，报告包被丢弃。
The value DT=11 is reserved for future definition and MUST NOT be sent, and MUST be discarded when received.
值DT=11保留用于将来的定义，不得发送，并且在接收时必须丢弃。
An endpoint MAY report any combination of discard types in each reporting interval by including several Discard Count Metrics Blocks in a single RTCP XR packet.
端点可以通过在单个RTCP XR数据包中包含多个丢弃计数度量块来报告每个报告间隔中丢弃类型的任何组合。
Some systems send duplicate RTP packets for robustness or error resilience. This is NOT RECOMMENDED since it breaks RTCP packet statistics. If duplication is desired for error resilience, the mechanism described in [RTPDUP] can be used, since this will not cause breakage of RTP streams or RTCP statistics.
一些系统发送重复的RTP数据包以增强健壮性或抗错误能力。不建议这样做，因为它会破坏RTCP数据包统计信息。如果需要复制以实现错误恢复能力，则可以使用[RTPDUP]中描述的机制，因为这不会导致RTP流或RTCP统计数据的中断。
Reserved (resv): 4 bits
保留（resv）：4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 length of this report block in 32-bit words, minus one, in accordance with the definition in [RFC3611]. This field MUST be set to 2 to match the fixed length of the report block. The block MUST be discarded if the block length is set to a different value.
根据[RFC3611]中的定义，此报告块的长度（以32位字减去1表示）。此字段必须设置为2，以匹配报告块的固定长度。如果块长度设置为不同的值，则必须丢弃该块。
SSRC of Source: 32 bits
源的SSRC：32位
As defined in Section 4.1 of [RFC3611].
如[RFC3611]第4.1节所定义。
Discard Count
丢弃计数
Number of packets discarded over the period (Interval or Cumulative) covered by this report.
在此报告覆盖的时间段（间隔或累积）内丢弃的数据包数。
The measured value is an unsigned value. If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE MUST be reported to indicate an over-range measurement. If the measurement is unavailable, the value 0xFFFFFFFF MUST be reported.
测量值为无符号值。如果测量值超过0xFFFFFD，则必须报告0xFFFFFFFE值以指示超量程测量。如果测量不可用，则必须报告值0xFFFFFFFF。
Note that the number of packets expected in the period associated with this metric (whether Interval or Cumulative) is available from the difference between a pair of extended sequence numbers in the Measurement Information Block [RFC6776], so it need not be repeated in this block.
注意，在与该度量相关联的时段（无论是间隔还是累积）中预期的数据包数量可从测量信息块[RFC6776]中的一对扩展序列号之间的差中获得，因此无需在该块中重复。
[RFC3611] defines the use of the Session Description Protocol (SDP) [RFC4566] for signaling the use of XR blocks. However, XR blocks MAY be used without prior signaling (see Section 5 of RFC 3611).
[RFC3611]定义了会话描述协议（SDP）[RFC4566]的使用，用于发送使用XR块的信号。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 section augments the SDP [RFC4566] attribute "rtcp-xr" defined in [RFC3611] by providing an additional value of "xr-format" to signal the use of the report block defined in this document. The ABNF [RFC5234] syntax is as follows.
本节增加了[RFC3611]中定义的SDP[RFC4566]属性“rtcp xr”，提供了“xr format”的附加值，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-pdc-block xr-pdc-block = "pkt-discard-count"
xr format=/xr pdc block xr pdc block=“pkt放弃计数”
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 block types for RTCP XR are subject to IANA registration. For general guidelines on IANA considerations for RTCP XR, refer to [RFC3611].
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[RFC3611]。
This document assigns the block type value 24 in the IANA "RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry" to the "Discard Count 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24分配给“丢弃计数度量块”。
This document also registers a new parameter "pkt-discard-count" 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“pkt丢弃计数”。
The following contact information is provided for all registrations in this document:
本文件中提供了所有注册的以下联系信息：
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
In some situations, returning very detailed error information (e.g., over-range measurement or measurement unavailable) using this report block can provide an attacker with insight into the security processing. Where this is a concern, the implementation should apply encryption and authentication to this report block. For example, this can be achieved by using the Audio-Visual Profile with Feedback (AVPF) profile together with the Secure RTP profile, as defined in [RFC3711]; an appropriate combination of those two profiles ("SAVPF") is specified in [RFC5124].
在某些情况下，使用此报告块返回非常详细的错误信息（例如，超范围测量或测量不可用）可以让攻击者深入了解安全处理。考虑到这一点，实现应该对此报告块应用加密和身份验证。例如，如[RFC3711]中所定义，这可以通过使用带反馈的视听配置文件（AVPF）配置文件以及安全RTP配置文件来实现；[RFC5124]中规定了这两个配置文件的适当组合（“SAVPF”）。
Besides this, it is believed that this RTCP XR block introduces no new security considerations beyond those described in [RFC3611]. This block does not provide per-packet statistics, so the risk to confidentiality documented in Section 7, paragraph 3 of [RFC3611] does not apply.
除此之外，人们认为，除了[RFC3611]中所述的安全注意事项外，该RTCP XR块没有引入任何新的安全注意事项。该块不提供每包统计数据，因此[RFC3611]第7节第3段中记录的保密风险不适用。
Geoff Hunt wrote the initial draft of this document.
杰夫·亨特撰写了这份文件的初稿。
The authors gratefully acknowledge reviews and feedback provided by Bruce Adams, Philip Arden, Amit Arora, Claire Bi, Bob Biskner, Gonzalo Camarillo, Benoit Claise, Kevin Connor, Claus Dahm, Spencer Dawkins, Randy Ethier, Roni Even, Stephen Farrel, Jim Frauenthal, Kevin Gross, Albert Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, Jonathan Lennox, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi Raviraj, Dan Romascanu, Albrecht Schwarz, Varun Singh, Tom Taylor, Dan Wing, and Hideaki Yamada.
作者感谢Bruce Adams、Philip Arden、Amit Arora、Claire Bi、Bob Biskner、Gonzalo Camarillo、Benoit Claise、Kevin Connor、Claus Dahm、Spencer Dawkins、Randy Ethier、Roni Even、Stephen Farrel、Jim Frauenthal、Kevin Gross、Albert Higashi、Tom Hock、Shane Holthaus、Paul Jones、Rajesh Kumar、，Keith Lantz、Jonathan Lennox、Mohamed Mostafa、Amy Pendleton、Colin Perkins、Mike Ramalho、Ravi Ravi、Dan Romascanu、Albrecht Schwarz、Varun Singh、Tom Taylor、Dan Wing和Hideaki Yamada。
[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。
[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。
[RFC4588] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. Hakenberg, "RTP Retransmission Payload Format", RFC 4588, July 2006.
[RFC4588]Rey，J.，Leon，D.，Miyazaki，A.，Varsa，V.，和R.Hakenberg，“RTP重传有效载荷格式”，RFC 4588，2006年7月。
[RFC5109] Li, A., "RTP Payload Format for Generic Forward Error Correction", RFC 5109, December 2007.
[RFC5109]Li，A.“通用前向纠错的RTP有效载荷格式”，RFC 5109，2007年12月。
[RFC5481] Morton, A. and B. Claise, "Packet Delay Variation Applicability Statement", RFC 5481, March 2009.
[RFC5481]Morton，A.和B.Claise，“数据包延迟变化适用性声明”，RFC 54812009年3月。
[RFC5725] Begen, A., Hsu, D., and M. Lague, "Post-Repair Loss RLE Report Block Type for RTP Control Protocol (RTCP) Extended Reports (XRs)", RFC 5725, February 2010.
[RFC5725]Begen，A.，Hsu，D.，和M.Lague，“RTP控制协议（RTCP）扩展报告（XRs）的修复后损失RLE报告块类型”，RFC 5725，2010年2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。
[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。
[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。
[RTPDUP] Begen, A. and C. Perkins, "Duplicating RTP Streams", Work in Progress, March 2013.
[RTPDUP]Begen，A.和C.Perkins，“复制RTP流”，正在进行的工作，2013年3月。
a. Number of Packets Discarded Metric
a. 丢弃的数据包数度量
* Metric Name: Number of RTP packets discarded.
* 度量名称：丢弃的RTP数据包数。
* Metric Description: Number of RTP packets discarded over the period covered by this report.
* 指标说明：在本报告涵盖的期间内丢弃的RTP数据包数。
* Method of Measurement or Calculation: See Section 3.2, Discard Count definition.
* 测量或计算方法：见第3.2节，丢弃计数定义。
* Units of Measurement: See Section 3.2, Discard Count definition.
* 计量单位：见第3.2节，报废计数定义。
* Measurement Point(s) with Potential Measurement Domain: See Section 3, 1st paragraph.
* 具有潜在测量域的测量点：见第3节第1段。
* Measurement Timing: See Section 3, 1st paragraph for measurement timing and Section 3.2 for Interval Metric flag.
* 测量时间：测量时间见第3节第1段，间隔公制标志见第3.2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。
Authors' Addresses
作者地址
Alan Clark Telchemy Incorporated 2905 Premiere Parkway, Suite 280 Duluth, GA 30097 USA
Alan Clark Telchemy Incorporated 2905 Premiere Parkway，美国佐治亚州德卢斯280号套房，邮编30097
EMail: alan.d.clark@telchemy.com
EMail: alan.d.clark@telchemy.com
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
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: sunseawq@huawei.com
EMail: sunseawq@huawei.com