Internet Engineering Task Force (IETF) S. Poretsky
Request for Comments: 6414 Allot Communications
Category: Informational R. Papneja
ISSN: 2070-1721 Huawei
J. Karthik
S. Vapiwala
Cisco Systems
November 2011
Internet Engineering Task Force (IETF) S. Poretsky
Request for Comments: 6414 Allot Communications
Category: Informational R. Papneja
ISSN: 2070-1721 Huawei
J. Karthik
S. Vapiwala
Cisco Systems
November 2011
Benchmarking Terminology for Protection Performance
保护性能基准术语
Abstract
摘要
This document provides common terminology and metrics for benchmarking the performance of sub-IP layer protection mechanisms. The performance benchmarks are measured at the IP layer; protection may be provided at the sub-IP layer. The benchmarks and terminology can be applied in methodology documents for different sub-IP layer protection mechanisms such as Automatic Protection Switching (APS), Virtual Router Redundancy Protocol (VRRP), Stateful High Availability (HA), and Multiprotocol Label Switching Fast Reroute (MPLS-FRR).
本文档提供了用于对子IP层保护机制的性能进行基准测试的通用术语和指标。在IP层测量性能基准；可以在子IP层提供保护。基准测试和术语可应用于不同子IP层保护机制（如自动保护交换（APS）、虚拟路由器冗余协议（VRRP）、有状态高可用性（HA）和多协议标签交换快速重路由（MPLS-FRR））的方法文档中。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
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). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see 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。并非IESG批准的所有文件都适用于任何级别的互联网标准；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/rfc6414.
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/rfc6414.
Copyright Notice
版权公告
Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2011 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。
This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.
本文件可能包含2008年11月10日之前发布或公开的IETF文件或IETF贡献中的材料。控制某些材料版权的人员可能未授予IETF信托允许在IETF标准流程之外修改此类材料的权利。在未从控制此类材料版权的人员处获得充分许可的情况下，不得在IETF标准流程之外修改本文件，也不得在IETF标准流程之外创建其衍生作品，除了将其格式化以RFC形式发布或将其翻译成英语以外的其他语言。
Table of Contents
目录
1. Introduction ....................................................4
1.1. Scope ......................................................4
1.2. General Model ..............................................5
2. Existing Definitions ............................................8
3. Test Considerations .............................................9
3.1. Paths ......................................................9
3.1.1. Path ................................................9
3.1.2. Working Path .......................................10
3.1.3. Primary Path .......................................10
3.1.4. Protected Primary Path .............................11
3.1.5. Backup Path ........................................11
3.1.6. Standby Backup Path ................................12
3.1.7. Dynamic Backup Path ................................12
3.1.8. Disjoint Paths .....................................13
3.1.9. Point of Local Repair (PLR) ........................13
3.1.10. Shared Risk Link Group (SRLG) .....................14
3.2. Protection ................................................14
3.2.1. Link Protection ....................................14
3.2.2. Node Protection ....................................15
1. Introduction ....................................................4
1.1. Scope ......................................................4
1.2. General Model ..............................................5
2. Existing Definitions ............................................8
3. Test Considerations .............................................9
3.1. Paths ......................................................9
3.1.1. Path ................................................9
3.1.2. Working Path .......................................10
3.1.3. Primary Path .......................................10
3.1.4. Protected Primary Path .............................11
3.1.5. Backup Path ........................................11
3.1.6. Standby Backup Path ................................12
3.1.7. Dynamic Backup Path ................................12
3.1.8. Disjoint Paths .....................................13
3.1.9. Point of Local Repair (PLR) ........................13
3.1.10. Shared Risk Link Group (SRLG) .....................14
3.2. Protection ................................................14
3.2.1. Link Protection ....................................14
3.2.2. Node Protection ....................................15
3.2.3. Path Protection ....................................15
3.2.4. Backup Span ........................................16
3.2.5. Local Link Protection ..............................16
3.2.6. Redundant Node Protection ..........................17
3.2.7. State Control Interface ............................17
3.2.8. Protected Interface ................................18
3.3. Protection Switching ......................................18
3.3.1. Protection-Switching System ........................18
3.3.2. Failover Event .....................................19
3.3.3. Failure Detection ..................................19
3.3.4. Failover ...........................................20
3.3.5. Restoration ........................................20
3.3.6. Reversion ..........................................21
3.4. Nodes .....................................................22
3.4.1. Protection-Switching Node ..........................22
3.4.2. Non-Protection-Switching Node ......................22
3.4.3. Headend Node .......................................23
3.4.4. Backup Node ........................................23
3.4.5. Merge Node .........................................24
3.4.6. Primary Node .......................................24
3.4.7. Standby Node .......................................25
3.5. Benchmarks ................................................26
3.5.1. Failover Packet Loss ...............................26
3.5.2. Reversion Packet Loss ..............................26
3.5.3. Failover Time ......................................27
3.5.4. Reversion Time .....................................27
3.5.5. Additive Backup Delay ..............................28
3.6. Failover Time Calculation Methods .........................28
3.6.1. Time-Based Loss Method (TBLM) ......................29
3.6.2. Packet-Loss-Based Method (PLBM) ....................29
3.6.3. Timestamp-Based Method (TBM) .......................30
4. Security Considerations ........................................31
5. References .....................................................32
5.1. Normative References ......................................32
5.2. Informative References ....................................32
6. Acknowledgments ................................................32
3.2.3. Path Protection ....................................15
3.2.4. Backup Span ........................................16
3.2.5. Local Link Protection ..............................16
3.2.6. Redundant Node Protection ..........................17
3.2.7. State Control Interface ............................17
3.2.8. Protected Interface ................................18
3.3. Protection Switching ......................................18
3.3.1. Protection-Switching System ........................18
3.3.2. Failover Event .....................................19
3.3.3. Failure Detection ..................................19
3.3.4. Failover ...........................................20
3.3.5. Restoration ........................................20
3.3.6. Reversion ..........................................21
3.4. Nodes .....................................................22
3.4.1. Protection-Switching Node ..........................22
3.4.2. Non-Protection-Switching Node ......................22
3.4.3. Headend Node .......................................23
3.4.4. Backup Node ........................................23
3.4.5. Merge Node .........................................24
3.4.6. Primary Node .......................................24
3.4.7. Standby Node .......................................25
3.5. Benchmarks ................................................26
3.5.1. Failover Packet Loss ...............................26
3.5.2. Reversion Packet Loss ..............................26
3.5.3. Failover Time ......................................27
3.5.4. Reversion Time .....................................27
3.5.5. Additive Backup Delay ..............................28
3.6. Failover Time Calculation Methods .........................28
3.6.1. Time-Based Loss Method (TBLM) ......................29
3.6.2. Packet-Loss-Based Method (PLBM) ....................29
3.6.3. Timestamp-Based Method (TBM) .......................30
4. Security Considerations ........................................31
5. References .....................................................32
5.1. Normative References ......................................32
5.2. Informative References ....................................32
6. Acknowledgments ................................................32
The IP network layer provides route convergence to protect data traffic against planned and unplanned failures in the Internet. Fast convergence times are critical to maintain reliable network connectivity and performance. Convergence Events [6] are recognized at the IP Layer so that Route Convergence [6] occurs. Technologies that function at sub-IP layers can be enabled to provide further protection of IP traffic by providing the failure recovery at the sub-IP layers so that the outage is not observed at the IP layer. Such sub-IP protection technologies include, but are not limited to, High Availability (HA) stateful failover, Virtual Router Redundancy Protocol (VRRP) [8], Automatic Link Protection (APS) for SONET/SDH, Resilient Packet Ring (RPR) for Ethernet, and Fast Reroute for Multiprotocol Label Switching (MPLS-FRR) [9].
IP网络层提供路由聚合，以保护数据流量不受Internet中计划内和计划外故障的影响。快速收敛时间对于保持可靠的网络连接和性能至关重要。在IP层识别汇聚事件[6]，从而发生路由汇聚[6]。通过在子IP层提供故障恢复，使在子IP层运行的技术能够提供进一步的IP流量保护，从而在IP层不会观察到中断。此类子IP保护技术包括但不限于高可用性（HA）状态故障切换、虚拟路由器冗余协议（VRRP）[8]、SONET/SDH的自动链路保护（APS）、以太网的弹性分组环（RPR）以及多协议标签交换的快速重路由（MPLS-FRR）[9]。
Benchmarking terminology was defined for IP-layer convergence in [6]. Different terminology and methodologies specific to benchmarking sub-IP layer protection mechanisms are required. The metrics for benchmarking the performance of sub-IP protection mechanisms are measured at the IP layer, so that the results are always measured in reference to IP and independent of the specific protection mechanism being used. The purpose of this document is to provide a single terminology for benchmarking sub-IP protection mechanisms.
[6]中定义了IP层融合的基准术语。需要针对基准子IP层保护机制的不同术语和方法。用于对子IP保护机制的性能进行基准测试的指标是在IP层进行测量的，因此，测量结果始终参考IP，并且与所使用的特定保护机制无关。本文件的目的是为基准子IP保护机制提供一个术语。
A common terminology for sub-IP layer protection mechanism benchmarking enables different implementations of a protection mechanism to be benchmarked and evaluated. In addition, implementations of different protection mechanisms can be benchmarked and evaluated. It is intended that there can exist unique methodology documents for each sub-IP protection mechanism based upon this common terminology document. The terminology can be applied to methodologies that benchmark sub-IP protection mechanism performance with a single stream of traffic or multiple streams of traffic. The traffic flow may be unidirectional or bidirectional as to be indicated in the methodology.
子IP层保护机制基准测试的通用术语允许对保护机制的不同实现进行基准测试和评估。此外，可以对不同保护机制的实现进行基准测试和评估。根据本通用术语文件，每个子IP保护机制都可以有独特的方法文件。该术语可应用于使用单个流量流或多个流量流对子IP保护机制性能进行基准测试的方法。如方法中所示，交通流可以是单向的或双向的。
The sequence of events to benchmark the performance of sub-IP protection mechanisms is as follows:
衡量子IP保护机制性能的事件顺序如下：
1. Failover Event - Primary Path fails 2. Failure Detection - Failover Event is detected 3. Failover - Backup Path becomes the Working Path due to Failover Event 4. Restoration - Primary Path recovers from a Failover Event 5. Reversion (optional) - Primary Path becomes the Working Path
1. 故障转移事件-主路径失败2。故障检测-检测到故障转移事件3。故障转移-由于故障转移事件4，备份路径成为工作路径。恢复-主路径从故障转移事件5中恢复。反转（可选）-主路径成为工作路径
These terms are further defined in this document.
这些术语在本文件中有进一步定义。
Figures 1 through 5 show models that MAY be used when benchmarking sub-IP protection mechanisms, which MUST use a Protection-Switching System that consists of a minimum of two Protection-Switching Nodes, an Ingress Node known as the Headend Node and an Egress Node known as the Merge Node. The Protection-Switching System MUST include either a Primary Path and Backup Path, as shown in Figures 1 through 4, or a Primary Node and Standby Node, as shown in Figure 5. A Protection-Switching System may provide link protection, node protection, path protection, local link protection, and high availability, as shown in Figures 1 through 5, respectively. A Failover Event occurs along the Primary Path or at the Primary Node. The Working Path is the Primary Path prior to the Failover Event and the Backup Path after the Failover Event. A Tester is set outside the two paths or nodes as it sends and receives IP traffic along the Working Path. The tester MUST record the IP packet sequence numbers, departure time, and arrival time so that the metrics of Failover Time, Additive Latency, Packet Reordering, Duplicate Packets, and Reversion Time can be measured. The Tester may be a single device or a test system. If Reversion is supported, then the Working Path is the Primary Path after Restoration (Failure Recovery) of the Primary Path.
图1至图5显示了对子IP保护机制进行基准测试时可能使用的模型，该机制必须使用至少由两个保护交换节点组成的保护交换系统，一个入口节点称为前端节点，一个出口节点称为合并节点。保护交换系统必须包括主路径和备用路径，如图1至图4所示，或主节点和备用节点，如图5所示。保护交换系统可提供链路保护、节点保护、路径保护、本地链路保护和高可用性，分别如图1至图5所示。故障转移事件沿主路径或主节点发生。工作路径是故障转移事件之前的主路径和故障转移事件之后的备份路径。当测试器沿着工作路径发送和接收IP流量时，它被设置在两个路径或节点之外。测试人员必须记录IP数据包序列号、离开时间和到达时间，以便可以测量故障切换时间、附加延迟、数据包重新排序、重复数据包和恢复时间。测试仪可以是单个设备或测试系统。如果支持恢复，则工作路径是主路径恢复（故障恢复）后的主路径。
Link Protection, as shown in Figure 1, provides protection when a Failover Event occurs on the link between two nodes along the Primary Path. Node Protection, as shown in Figure 2, provides protection when a Failover Event occurs at a Node along the Primary Path. Path Protection, as shown in Figure 3, provides protection for link or node failures for multiple hops along the Primary Path. Local Link Protection, as shown in Figure 4, provides sub-IP protection of a link between two nodes, without a Backup Node. An example of such a sub-IP protection mechanism is SONET APS. High Availability Protection, as shown in Figure 5, provides protection of a Primary Node with a redundant Standby Node. State Control is provided between the Primary and Standby Nodes. Failure of the Primary Node
链路保护，如图1所示，在沿主路径的两个节点之间的链路上发生故障转移事件时提供保护。节点保护，如图2所示，在主路径上的节点发生故障转移事件时提供保护。如图3所示，路径保护为沿主路径的多个跃点的链路或节点故障提供保护。如图4所示，本地链路保护为两个节点之间的链路提供子IP保护，而无需备份节点。SONET APS就是这种子IP保护机制的一个例子。高可用性保护（如图5所示）为主节点和冗余备用节点提供保护。在主节点和备用节点之间提供状态控制。主节点发生故障
is detected at the sub-IP layer to force traffic to switch to the Standby Node, which has state maintained for zero or minimal packet loss.
在子IP层检测到，以强制流量切换到备用节点，备用节点的状态保持为零或最小数据包丢失。
+-----------+
+--------------| Tester |<-----------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| ------------ | ---------- |
+--->| Ingress/ | V | Egress/ |---+
|Headend Node|------------------|Merge Node| Primary
------------ ---------- Path
| ^
| --------- | Backup
+--------| Backup |-------------+ Path
| Node |
---------
+-----------+
+--------------| Tester |<-----------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| ------------ | ---------- |
+--->| Ingress/ | V | Egress/ |---+
|Headend Node|------------------|Merge Node| Primary
------------ ---------- Path
| ^
| --------- | Backup
+--------| Backup |-------------+ Path
| Node |
---------
Figure 1. System Under Test (SUT) for Sub-IP Link Protection
图1。子IP链路保护的测试中系统（SUT）
+-----------+
+--------------------| Tester |<-----------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| V |
| ------------ -------- ---------- |
+--->| Ingress/ | |Midpoint| | Egress/ |---+
|Headend Node|----| Node |----|Merge Node| Primary
------------ -------- ---------- Path
| ^
| --------- | Backup
+--------| Backup |-------------+ Path
| Node |
---------
+-----------+
+--------------------| Tester |<-----------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| V |
| ------------ -------- ---------- |
+--->| Ingress/ | |Midpoint| | Egress/ |---+
|Headend Node|----| Node |----|Merge Node| Primary
------------ -------- ---------- Path
| ^
| --------- | Backup
+--------| Backup |-------------+ Path
| Node |
---------
Figure 2. System Under Test (SUT) for Sub-IP Node Protection
图2。子IP节点保护的测试中系统（SUT）
+-----------+
+---------------------------| Tester |<----------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| Primary Path | |
| ------------ -------- | -------- ---------- |
+--->| Ingress/ | |Midpoint| V |Midpoint| | Egress/ |---+
|Headend Node|----| Node |---| Node |---|Merge Node|
------------ -------- -------- ----------
| ^
| --------- -------- | Backup
+--------| Backup |----| Backup |--------+ Path
| Node | | Node |
--------- --------
+-----------+
+---------------------------| Tester |<----------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| Primary Path | |
| ------------ -------- | -------- ---------- |
+--->| Ingress/ | |Midpoint| V |Midpoint| | Egress/ |---+
|Headend Node|----| Node |---| Node |---|Merge Node|
------------ -------- -------- ----------
| ^
| --------- -------- | Backup
+--------| Backup |----| Backup |--------+ Path
| Node | | Node |
--------- --------
Figure 3. System Under Test (SUT) for Sub-IP Path Protection
图3。子IP路径保护的测试中系统（SUT）
+-----------+
+--------------------| Tester |<-------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| Primary | |
| +--------+ Path v +--------+ |
| | |------------------------>| | |
+--->| Ingress| | Egress |----+
| Node |- - - - - - - - - - - - >| Node |
+--------+ Backup Path +--------+
| |
| IP-Layer Forwarding |
+<----------------------------------------->+
+-----------+
+--------------------| Tester |<-------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| Primary | |
| +--------+ Path v +--------+ |
| | |------------------------>| | |
+--->| Ingress| | Egress |----+
| Node |- - - - - - - - - - - - >| Node |
+--------+ Backup Path +--------+
| |
| IP-Layer Forwarding |
+<----------------------------------------->+
Figure 4. System Under Test (SUT) for Sub-IP Local Link Protection
图4。用于子IP本地链路保护的测试中系统（SUT）
+-----------+
+-----------------| Tester |<--------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| V |
| --------- -------- ---------- |
+--->| Ingress | |Primary | | Egress/ |------+
| Node |----| Node |----|Merge Node| Primary
--------- -------- ---------- Path
| State |Control ^
| Interface |(Optional) |
| --------- |
+---------| Standby |---------+
| Node |
---------
+-----------+
+-----------------| Tester |<--------------------+
| +-----------+ |
| IP Traffic | Failover IP Traffic |
| | Event |
| V |
| --------- -------- ---------- |
+--->| Ingress | |Primary | | Egress/ |------+
| Node |----| Node |----|Merge Node| Primary
--------- -------- ---------- Path
| State |Control ^
| Interface |(Optional) |
| --------- |
+---------| Standby |---------+
| Node |
---------
Figure 5. System Under Test (SUT) for Sub-IP Redundant Node Protection
图5。子IP冗余节点保护的测试中系统（SUT）
Some protection-switching technologies may use a series of steps that differ from the general model. The specific differences SHOULD be highlighted in each technology-specific methodology. Note that some protection-switching technologies are endowed with the ability to re-optimize the working path after a node or link failure.
一些保护开关技术可能使用一系列不同于一般模型的步骤。应在每种技术特定方法中强调具体差异。请注意，某些保护切换技术具有在节点或链路故障后重新优化工作路径的能力。
This document uses existing terminology defined in other BMWG work. Examples include, but are not limited to:
本文件使用其他BMWG工作中定义的现有术语。示例包括但不限于：
Latency [2], Section 3.8 Frame Loss Rate [2], Section 3.6 Throughput [2], Section 3.17 Device Under Test (DUT) [3], Section 3.1.1 System Under Test (SUT) [3], Section 3.1.2 Offered Load [3], Section 3.5.2 Out-of-order Packet [4], Section 3.3.4 Duplicate Packet [4], Section 3.3.5 Forwarding Delay [4], Section 3.2.4 Jitter [4], Section 3.2.5 Packet Loss [6], Section 3.5 Packet Reordering [7], Section 3.3
延迟[2]，第3.8节帧丢失率[2]，第3.6节吞吐量[2]，第3.17节被测设备（DUT）[3]，第3.1.1节被测系统（SUT）[3]，第3.1.2节提供负载[3]，第3.5.2节无序数据包[4]，第3.3.4节重复数据包[4]，第3.3.5节转发延迟[4]，第3.2.4节抖动[4]，第3.2.5节数据包丢失[6]，第3.5节数据包重新排序[7]，第3.3节
This document has the following frequently used acronyms:
本文件有以下常用缩略语：
DUT Device Under Test SUT System Under Test
被测装置被测系统被测
This document adopts the definition format in Section 2 of RFC 1242 [2]. Terms defined in this document are capitalized when used within this document.
本文件采用RFC 1242[2]第2节中的定义格式。本文件中定义的术语在本文件中使用时大写。
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14, RFC 2119 [5]. RFC 2119 defines the use of these keywords to help make the intent of Standards Track documents as clear as possible. While this document uses these keywords, this document is not a Standards Track document.
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不得”、“应”、“不应”、“建议”、“可”和“可选”应按照BCP 14、RFC 2119[5]中的描述进行解释。RFC 2119定义了这些关键字的使用，以帮助使标准跟踪文档的意图尽可能清晰。虽然本文档使用这些关键字，但本文档不是标准跟踪文档。
Definition: A unidirectional sequence of nodes <R1, ..., Rn> and links <L12,... L(n-1)n> with the following properties:
定义：节点<R1，…，Rn>和链接<L12，。。。L（n-1）n>具有以下性质：
a. R1 is the ingress node and forwards IP packets, which input into DUT/SUT, to R2 as sub-IP frames over link L12.
a. R1是入口节点，通过链路L12将输入DUT/SUT的IP数据包作为子IP帧转发给R2。
b. Ri is a node which forwards data frames to R(i+1) over Link Li(i+1) for all i, 1<i<n-1, based on information in the sub-IP layer.
b. Ri是基于子IP层中的信息，通过链路Li（i+1）将所有i，1<i<n-1的数据帧转发给R（i+1）的节点。
c. Rn is the egress node, and it outputs sub-IP frames from DUT/SUT as IP packets. L(n-1)n is the link between the R(n-1) and Rn.
c. Rn是出口节点，它将来自DUT/SUT的子IP帧作为IP包输出。L（n-1）n是R（n-1）和Rn之间的链路。
Discussion: The path is defined in the sub-IP layer in this document, unlike an IP path in RFC 2026 [1]. One path may be regarded as being equivalent to one IP link between two IP nodes, i.e., R1 and Rn. The two IP nodes may have multiple paths for protection. A packet will travel on only one path between the nodes. Packets belonging to a microflow [10] will traverse one or more paths. The path is unidirectional. For example, the link between R1 and R2 in the direction from R1 to R2 is L12. For traffic flowing in the reverse direction from R2 to R1, the link is L21. Example paths are the SONET/SDH path and the label switched path for MPLS.
讨论：与RFC 2026[1]中的IP路径不同，该路径在本文档的子IP层中定义。一条路径可被视为相当于两个IP节点（即R1和Rn）之间的一条IP链路。这两个IP节点可以有多条路径进行保护。一个数据包将只在节点之间的一条路径上传输。属于微流[10]的数据包将穿越一条或多条路径。路径是单向的。例如，从R1到R2方向上R1和R2之间的链接为L12。对于反向从R2流向R1的流量，链路为L21。示例路径是SONET/SDH路径和MPLS的标签交换路径。
Measurement Units: n/a
计量单位：不适用
Issues: "A bidirectional path", which transmits traffic in both directions along the same nodes, consists of two unidirectional paths. Therefore, the two unidirectional paths belonging to "one bidirectional path" will be treated independently when benchmarking for "a bidirectional path".
问题：“双向路径”沿同一节点在两个方向上传输流量，由两条单向路径组成。因此，在对“双向路径”进行基准测试时，属于“一条双向路径”的两条单向路径将被独立处理。
See Also: Working Path Primary Path Backup Path
另请参见：工作路径主路径备份路径
Definition: The path that the DUT/SUT is currently using to forward packets.
定义：DUT/SUT当前用于转发数据包的路径。
Discussion: A Primary Path is the Working Path before occurrence of a Failover Event. A Backup Path shall become the Working Path after a Failover Event.
讨论：主路径是故障转移事件发生之前的工作路径。故障转移事件发生后，备份路径应成为工作路径。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Primary Path Backup Path
另请参见：路径主路径备份路径
Definition: The preferred point-to-point path for forwarding traffic between two or more nodes.
定义：在两个或多个节点之间转发流量的首选点对点路径。
Discussion: The Primary Path is the Path that traffic traverses prior to a Failover Event.
讨论：主路径是故障转移事件之前流量所经过的路径。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Failover Event
另请参见：路径故障转移事件
Definition: A Primary Path that is protected with a Backup Path.
定义：受备份路径保护的主路径。
Discussion: A Protected Primary Path must include at least one Protection-Switching Node.
讨论：受保护的主路径必须至少包括一个保护交换节点。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Primary Path
另请参见：路径主路径
Definition: A path that exists to carry data traffic only if a Failover Event occurs on a Primary Path.
定义：仅当主路径上发生故障转移事件时才承载数据流量的路径。
Discussion: The Backup Path shall become the Working Path upon a Failover Event. A Path may have one or more Backup Paths. A Backup Path may protect one or more Primary Paths. There are various types of Backup Paths:
讨论：发生故障转移事件时，备份路径应成为工作路径。路径可以有一个或多个备份路径。备份路径可以保护一个或多个主路径。有多种类型的备份路径：
a. dedicated recovery Backup Path (1+1) or (1:1), which has 100% redundancy for a specific ordinary path
a. 专用恢复备份路径（1+1）或（1:1），对于特定的普通路径具有100%冗余
b. shared Backup Path (1:N), which is dedicated to the protection for more than one specific Primary Path
b. 共享备份路径（1:N），专用于保护多个特定主路径
c. associated shared Backup Path (M:N) for which a specific set of Backup Paths protects a specific set of more than one Primary Path
c. 关联的共享备份路径（M:N），其中一组特定备份路径保护一组特定的多个主路径
A Backup Path may be signaled or unsignaled. The Backup Path must be created prior to the Failover Event. The Backup Path generally originates at the point of local repair (PLR) and terminates at a node along a primary path.
备份路径可以是有信号的或无信号的。必须在故障转移事件之前创建备份路径。备份路径通常起源于本地修复点（PLR），终止于主路径上的节点。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Working Path Primary Path
另请参见：路径工作路径主路径
Definition: A Backup Path that is established prior to a Failover Event to protect a Primary Path.
定义：在故障转移事件之前建立的备份路径，用于保护主路径。
Discussion: The Standby Backup Path and Dynamic Backup Path provide protection, but are established at different times.
讨论：备用备份路径和动态备份路径提供保护，但在不同的时间建立。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Backup Path Primary Path Failover Event
另请参见：备份路径主路径故障切换事件
Definition: A Backup Path that is established upon occurrence of a Failover Event.
定义：在发生故障转移事件时建立的备份路径。
Discussion: The Standby Backup Path and Dynamic Backup Path provide protection, but are established at different times.
讨论：备用备份路径和动态备份路径提供保护，但在不同的时间建立。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Backup Path Standby Backup Path Failover Event
另请参见：备份路径备用备份路径故障切换事件
Definition: A pair of paths that do not share a common link or nodes.
定义：不共享公共链接或节点的一对路径。
Discussion: Two paths are disjoint if they do not share a common node or link other than the ingress and egress.
讨论：如果两条路径不共享除入口和出口之外的公共节点或链路，则它们是不相交的。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Primary Path SRLG
另请参见：路径主路径SRLG
Definition: A node capable of Failover along the Primary Path that is also the ingress node for the Backup Path to protect another node or link.
定义：能够沿主路径进行故障切换的节点，也是备份路径的入口节点，以保护另一个节点或链路。
Discussion: Any node along the Primary Path from the ingress node to the penultimate node may be a PLR. The PLR may use a single Backup Path for protecting one or more Primary Paths. There can be multiple PLRs along a Primary Path. The PLR must be an ingress to a Backup Path. The PLR can be any node along the Primary Path except the egress node of the Primary Path. The PLR may simultaneously be a Headend Node when it is serving the role as ingress to the Primary Path and the Backup Path. If the PLR is also the Headend Node, then the Backup Path is a Disjoint Path from the ingress to the Merge Node.
讨论：从入口节点到倒数第二个节点的主路径上的任何节点都可能是PLR。PLR可以使用单个备份路径来保护一个或多个主路径。沿着主路径可以有多个PLR。PLR必须是备份路径的入口。PLR可以是主路径上除主路径的出口节点之外的任何节点。当PLR充当主路径和备份路径的入口时，它可以同时是头端节点。如果PLR也是前端节点，则备份路径是从入口到合并节点的不相交路径。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path Failover
另请参见：主路径备份路径故障切换
Definition: SRLG is a set of links that share the same risk (physical or logical) within a network.
定义：SRLG是一组在网络中共享相同风险（物理或逻辑）的链路。
Discussion: SRLG is considered the set of links to be avoided when the primary and secondary paths are considered disjoint. The SRLG will fail as a group if the shared resource (physical or anything abstract such as software version) fails.
讨论：当主路径和次路径不相交时，SRLG被认为是要避免的链路集。如果共享资源（物理资源或任何抽象资源，如软件版本）失败，SRLG将作为一个组失败。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Primary Path
另请参见：路径主路径
Definition: A Backup Path that is signaled to at least one Backup Node to protect for failure of interfaces and links along a Primary Path.
定义：向至少一个备份节点发送信号的备份路径，以防止主路径上的接口和链路出现故障。
Discussion: Link Protection may or may not protect the entire Primary Path. Link Protection is shown in Figure 1.
讨论：链路保护可能保护也可能不保护整个主路径。链路保护如图1所示。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path
另请参见：主路径备份路径
Definition: A Backup Path that is signaled to at least one Backup Node to protect for failure of interfaces, links, and nodes along a Primary Path.
定义：向至少一个备份节点发送信号的备份路径，以防止主路径上的接口、链路和节点出现故障。
Discussion: Node Protection may or may not protect the entire Primary Path. Node Protection also provides Link Protection. Node Protection is shown in Figure 2.
讨论：节点保护可能会也可能不会保护整个主路径。节点保护还提供链路保护。节点保护如图2所示。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Link Protection
另请参见：链接保护
Definition: A Backup Path that is signaled to at least one Backup Node to provide protection along the entire Primary Path.
定义：向至少一个备份节点发送信号以沿整个主路径提供保护的备份路径。
Discussion: Path Protection provides Node Protection and Link Protection for every node and link along the Primary Path. A Backup Path providing Path Protection may have the same ingress node as the Primary Path. Path Protection is shown in Figure 3.
讨论：路径保护为主路径上的每个节点和链路提供节点保护和链路保护。提供路径保护的备份路径可以具有与主路径相同的入口节点。路径保护如图3所示。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path Node Protection Link Protection
另请参见：主路径备份路径节点保护链路保护
Definition: The number of hops used by a Backup Path.
定义：备份路径使用的跃点数。
Discussion: The Backup Span is an integer obtained by counting the number of nodes along the Backup Path.
讨论：备份范围是一个整数，通过计算备份路径上的节点数获得。
Measurement Units: number of nodes
测量单位：节点数
Issues: None.
问题：没有。
See Also: Primary Path Backup Path
另请参见：主路径备份路径
Definition: A Backup Path that is a redundant path between two nodes and does not use a Backup Node.
定义：备份路径是两个节点之间的冗余路径，不使用备份节点。
Discussion: Local Link Protection must be provided as a Backup Path between two nodes along the Primary Path without the use of a Backup Node. Local Link Protection is provided by Protection-Switching Systems such as SONET APS. Local Link Protection is shown in Figure 4.
讨论：本地链路保护必须作为主路径上两个节点之间的备份路径提供，而无需使用备份节点。本地链路保护由保护交换系统（如SONET APS）提供。本地链路保护如图4所示。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Backup Path Backup Node
另请参见：备份路径备份节点
Definition: A Protection-Switching System with a Primary Node protected by a Standby Node along the Primary Path.
定义：一种保护交换系统，主节点沿主路径受备用节点保护。
Discussion: Redundant Node Protection is provided by Protection-Switching Systems such as VRRP and HA. The protection mechanisms occur at sub-IP layers to switch traffic from a Primary Node to Backup Node upon a Failover Event at the Primary Node. Traffic continues to traverse the Primary Path through the Standby Node. The failover may be stateful, in which the state information may be exchanged in-band or over an out-of-band State Control Interface. The Standby Node may be active or passive. Redundant Node Protection is shown in Figure 5.
讨论：冗余节点保护由保护交换系统（如VRRP和HA）提供。保护机制发生在子IP层，用于在主节点发生故障转移事件时将流量从主节点切换到备份节点。通信量继续通过备用节点穿过主路径。故障切换可以是有状态的，其中状态信息可以在带内或带外状态控制接口上交换。备用节点可以是主动的或被动的。冗余节点保护如图5所示。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Primary Node Standby Node
另请参见：主路径主节点备用节点
Definition: An out-of-band control interface used to exchange state information between the Primary Node and Standby Node.
定义：带外控制接口，用于在主节点和备用节点之间交换状态信息。
Discussion: The State Control Interface may be used for Redundant Node Protection. The State Control Interface should be out-of-band. It is possible to have Redundant Node Protection in which there is no state control or state control is provided in-band. The State Control Interface between the Primary and Standby Node may be one or more hops.
讨论：状态控制接口可用于冗余节点保护。状态控制接口应在带外。可以具有冗余节点保护，其中不存在状态控制或在频带内提供状态控制。主节点和备用节点之间的状态控制接口可以是一个或多个跃点。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Node Standby Node
另请参见：主节点备用节点
Definition: An interface along the Primary Path that is protected by a Backup Path.
定义：主路径上受备份路径保护的接口。
Discussion: A Protected Interface is an interface protected by a Protection-Switching System that provides Link Protection, Node Protection, Path Protection, Local Link Protection, and Redundant Node Protection.
讨论：受保护接口是由保护交换系统保护的接口，该系统提供链路保护、节点保护、路径保护、本地链路保护和冗余节点保护。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path
另请参见：主路径备份路径
Definition: A DUT/SUT that is capable of Failure Detection and Failover from a Primary Path to a Backup Path or Standby Node when a Failover Event occurs.
定义：一种DUT/SUT，当发生故障转移事件时，它能够检测故障并从主路径故障转移到备份路径或备用节点。
Discussion: The Protection-Switching System must include either a Primary Path and Backup Path, as shown in Figures 1 through 4, or a Primary Node and Standby Node, as shown in Figure 5. The Backup Path may be a Standby Backup Path or a Dynamic Backup Path. The Protection-Switching System includes the mechanisms for both Failure Detection and Failover.
讨论：保护交换系统必须包括主路径和备用路径，如图1至图4所示，或主节点和备用节点，如图5所示。备份路径可以是备用备份路径或动态备份路径。保护交换系统包括故障检测和故障切换机制。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path Failover
另请参见：主路径备份路径故障切换
Definition: The occurrence of a planned or unplanned action in the network that results in a change in the Path that data traffic traverses.
定义：在网络中发生计划内或计划外操作，导致数据流量所经过的路径发生变化。
Discussion: Failover Events include, but are not limited to, link failure and router failure. Routing changes are considered Convergence Events [6] and are not Failover Events. This restricts Failover Events to sub-IP layers. Failover may be at the PLR or at the ingress. If the failover is at the ingress, it is generally on a disjoint path from the ingress to egress.
讨论：故障转移事件包括但不限于链路故障和路由器故障。路由更改被视为聚合事件[6]，而不是故障转移事件。这将故障转移事件限制到子IP层。故障切换可能在PLR或入口。如果故障切换位于入口，则它通常位于从入口到出口的不相交路径上。
Failover Events may result from failures such as link failure or router failure. The change in path after Failover may have a Backup Span of one or more nodes. Failover Events are distinguished from routing changes and Convergence Events [6] by the detection of the failure and subsequent protection switching at a sub-IP layer. Failover occurs at a PLR or Primary Node.
故障转移事件可能由链路故障或路由器故障等故障引起。故障转移后路径的更改可能具有一个或多个节点的备份范围。故障转移事件与路由更改和聚合事件[6]的区别在于在子IP层检测故障和随后的保护切换。故障转移发生在PLR或主节点上。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Path Failure Detection Disjoint Path
另请参见：路径故障检测不相交路径
Definition: The process to identify at a sub-IP layer a Failover Event at a Primary Node or along the Primary Path.
定义：在子IP层识别主节点或主路径上的故障转移事件的过程。
Discussion: Failure Detection occurs at the Primary Node or ingress node of the Primary Path. Failure Detection occurs via a sub-IP mechanism such as detection of a link down event or timeout for receipt of a control packet. A failure may be completely isolated. A failure
讨论：故障检测发生在主路径的主节点或入口节点。故障检测通过子IP机制发生，例如检测链路断开事件或接收控制数据包的超时。故障可能被完全隔离。失败
may affect a set of links that share a single SRLG (e.g., port with many sub-interfaces). A failure may affect multiple links that are not part of the SRLG.
可能影响共享单个SRLG的一组链路（例如，具有多个子接口的端口）。故障可能会影响不属于SRLG的多个链路。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path
另请参见：主路径
Definition: The process to switch data traffic from the protected Primary Path to the Backup Path upon Failure Detection of a Failover Event.
定义：在检测到故障转移事件时，将数据流量从受保护的主路径切换到备份路径的过程。
Discussion: Failover to a Backup Path provides Link Protection, Node Protection, or Path Protection. Failover is complete when Packet Loss [6], Out-of-order Packets [4], and Duplicate Packets [4] are no longer observed. Forwarding Delay [4] may continue to be observed.
讨论：故障切换到备份路径可提供链路保护、节点保护或路径保护。当不再观察到数据包丢失[6]、无序数据包[4]和重复数据包[4]时，故障转移完成。转发延迟[4]可能会继续被观察到。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path Failover Event
另请参见：主路径备份路径故障切换事件
Definition: The state of failover recovery in which the Primary Path has recovered from a Failover Event, but is not yet forwarding packets because the Backup Path remains the Working Path.
定义：故障转移恢复的状态，其中主路径已从故障转移事件中恢复，但由于备份路径仍然是工作路径，因此尚未转发数据包。
Discussion: Restoration must occur while the Backup Path is the Working Path. The Backup Path is maintained as the Working Path during Restoration. Restoration produces a Primary Path that is
讨论：必须在备份路径为工作路径时进行恢复。恢复期间，备份路径作为工作路径进行维护。恢复将生成一个主路径，该路径是
recovered from failure, but is not yet forwarding traffic. Traffic is still being forwarded by the Backup Path functioning as the Working Path.
已从故障中恢复，但尚未转发流量。作为工作路径的备份路径仍在转发通信量。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Failover Event Failure Recovery Working Path Backup Path
另请参见：主路径故障切换事件故障恢复工作路径备份路径
Definition: The state of failover recovery in which the Primary Path has become the Working Path so that it is forwarding packets.
定义：故障转移恢复的状态，其中主路径已成为工作路径，因此它正在转发数据包。
Discussion: Protection-Switching Systems may or may not support Reversion. Reversion, if supported, must occur after Restoration. Packet forwarding on the Primary Path resulting from Reversion may occur either fully or partially over the Primary Path. A potential problem with Reversion is the discontinuity in end-to-end delay when the Forwarding Delays [4] along the Primary Path and Backup Path are different, possibly causing Out-of-order Packets [4], Duplicate Packets [4], and increased Jitter [4].
讨论：保护开关系统可能支持也可能不支持反向。恢复（如果支持）必须在恢复后进行。由于恢复而在主路径上产生的分组转发可以全部或部分地在主路径上发生。反向的一个潜在问题是，当沿主路径和备份路径的转发延迟[4]不同时，端到端延迟不连续，可能导致无序数据包[4]、重复数据包[4]和抖动增加[4]。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Protection-Switching System Working Path Primary Path
另请参见：保护开关系统工作路径主路径
Definition: A node that is capable of participating in a Protection Switching System.
定义：能够参与保护切换系统的节点。
Discussion: The Protection-Switching Node may be an ingress or egress for a Primary Path or Backup Path, such as used for MPLS Fast Reroute configurations. The Protection-Switching Node may provide Redundant Node Protection as a Primary Node in a Redundant chassis configuration with a Standby Node, such as used for VRRP and HA configurations.
讨论：保护交换节点可以是主路径或备份路径的入口或出口，例如用于MPLS快速重路由配置。保护交换节点可以在具有备用节点的冗余机箱配置中作为主节点提供冗余节点保护，例如用于VRRP和HA配置。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Protection-Switching System
另见：保护开关系统
Definition: A node that is not capable of participating in a Protection Switching System, but may exist along the Primary Path or Backup Path.
定义：不能参与保护交换系统的节点，但可能存在于主路径或备份路径上。
Discussion: None.
讨论：无。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Protection-Switching System Primary Path Backup Path
另请参见：保护交换系统主路径备份路径
Definition: The ingress node of the Primary Path.
定义：主路径的入口节点。
Discussion: The Headend Node may also be a PLR when it is serving in the dual role as the ingress to the Backup Path.
讨论：当前端节点充当备份路径入口的双重角色时，它也可以是PLR。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path PLR Failover
另请参见：主路径PLR故障切换
Definition: A node along the Backup Path.
定义：沿备份路径的节点。
Discussion: The Backup Node can be any node along the Backup Path. There may be one or more Backup Nodes along the Backup Path. A Backup Node may be the ingress, midpoint, or egress of the Backup Path. If the Backup Path has only one Backup Node, then that Backup Node is the ingress and egress of the Backup Path.
讨论：备份节点可以是备份路径上的任何节点。备份路径上可能有一个或多个备份节点。备份节点可以是备份路径的入口、中点或出口。如果备份路径只有一个备份节点，则该备份节点是备份路径的入口和出口。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Backup Path
另请参见：备份路径
Definition: A node along the Primary Path where Backup Path terminates.
定义：主路径上备份路径终止的节点。
Discussion: The Merge Node can be any node along the Primary Path except the ingress node of the Primary Path. There can be multiple Merge Nodes along a Primary Path. A Merge Node can be the egress node for a single Backup Path or multiple Backup Paths. The Merge Node must be the egress to the Backup Path. The Merge Node may also be the egress of the Primary Path or Point of Local Repair (PLR).
讨论：合并节点可以是主路径上的任何节点，主路径的入口节点除外。沿主路径可以有多个合并节点。合并节点可以是单个备份路径或多个备份路径的出口节点。合并节点必须是备份路径的出口。合并节点还可以是主路径的出口或本地修复点（PLR）。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Path Backup Path PLR Failover
另请参见：主路径备份路径PLR故障切换
Definition: A node along the Primary Path that is capable of Failover to a redundant Standby Node.
定义：主路径上能够故障切换到冗余备用节点的节点。
Discussion: The Primary Node may be used for Protection-Switching Systems that provide Redundant Node Protection, such as VRRP and HA.
讨论：主节点可用于提供冗余节点保护的保护交换系统，如VRRP和HA。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Protection-Switching System Redundant Node Protection Standby Node
另见：保护开关系统冗余节点保护备用节点
Definition: A redundant node to a Primary Node; it forwards traffic along the Primary Path upon Failure Detection of the Primary Node.
定义：从冗余节点到主节点；当主节点检测到故障时，它沿着主路径转发通信量。
Discussion: The Standby Node must be used for Protection-Switching Systems that provide Redundant Node Protection, such as VRRP and HA. The Standby Node must provide protection along the same Primary Path. If the failover is to a Disjoint Path, then it is a Backup Node. The Standby Node may be configured for 1:1 or N:1 protection.
讨论：备用节点必须用于提供冗余节点保护的保护交换系统，如VRRP和HA。备用节点必须沿同一主路径提供保护。如果故障切换到不相交的路径，则它是备份节点。备用节点可以配置为1:1或N:1保护。
The communication between the Primary Node and Standby Node may be in-band or across an out-of-band State Control Interface. The Standby Node may be geographically dispersed from the Primary Node. When geographically dispersed, the number of hops of separation may increase failover time.
主节点和备用节点之间的通信可以是带内的或跨带外状态控制接口的。备用节点可以在地理上分散于主节点。在地理位置分散时，分离跳数可能会增加故障切换时间。
The Standby Node may be passive or active. The Passive Standby Node is not offered traffic and does not forward traffic until Failure Detection of the Primary Node. Upon Failure Detection of the Primary Node, traffic offered to the Primary Node is instead offered to the Passive Standby Node. The Active Standby Node is offered traffic and forwards traffic along the Primary Path while the Primary Node is also active. Upon Failure Detection of the Primary Node, traffic offered to the Primary Node is switched to the Active Standby Node.
备用节点可以是被动的或主动的。被动备用节点不提供流量，并且在主节点检测到故障之前不转发流量。在主节点检测到故障时，提供给主节点的通信量被提供给被动备用节点。主备节点被提供流量并沿主路径转发流量，而主节点也处于活动状态。在主节点检测到故障时，提供给主节点的业务被切换到主备节点。
Measurement Units: n/a
计量单位：不适用
Issues: None.
问题：没有。
See Also: Primary Node State Control Interface
另请参见：主节点状态控制接口
Definition: The amount of packet loss produced by a Failover Event until Failover completes, where the measurement begins when the last unimpaired packet is received by the Tester on the Protected Primary Path and ends when the first unimpaired packet is received by the Tester on the Backup Path.
定义：故障转移完成前故障转移事件产生的数据包丢失量，其中测量从测试仪在受保护的主路径上收到最后一个未损坏的数据包开始，到测试仪在备份路径上收到第一个未损坏的数据包结束。
Discussion: Packet loss can be observed as a reduction of forwarded traffic from the maximum forwarding rate. Failover Packet Loss includes packets that were lost, reordered, or delayed. Failover Packet Loss may reach 100% of the offered load.
讨论：数据包丢失可以看作是从最大转发速率减少了转发流量。故障转移数据包丢失包括丢失、重新排序或延迟的数据包。故障转移数据包丢失可能达到所提供负载的100%。
Measurement Units: Number of Packets
测量单位：数据包数
Issues: None.
问题：没有。
See Also: Failover Event Failover
另请参见：故障转移事件故障转移
Definition: The amount of packet loss produced by Reversion, where the measurement begins when the last unimpaired packet is received by the Tester on the Backup Path and ends when the first unimpaired packet is received by the Tester on the Protected Primary Path.
定义：恢复产生的数据包丢失量，当测试仪在备份路径上收到最后一个未损坏的数据包时，测量开始，当测试仪在受保护的主路径上收到第一个未损坏的数据包时，测量结束。
Discussion: Packet loss can be observed as a reduction of forwarded traffic from the maximum forwarding rate. Reversion Packet Loss includes packets that were lost, reordered, or delayed. Reversion Packet Loss may reach 100% of the offered load.
讨论：数据包丢失可以看作是从最大转发速率减少了转发流量。恢复数据包丢失包括丢失、重新排序或延迟的数据包。反向数据包丢失可能达到所提供负载的100%。
Measurement Units: Number of Packets
测量单位：数据包数
Issues: None.
问题：没有。
See Also: Reversion
另见：回归
Definition: The amount of time it takes for Failover to successfully complete.
定义：故障转移成功完成所需的时间。
Discussion: Failover Time can be calculated using the Time-Based Loss Method (TBLM), Packet-Loss-Based Method (PLBM), or Timestamp-Based Method (TBM). It is RECOMMENDED that the TBM is used.
讨论：可以使用基于时间的丢失方法（TBLM）、基于数据包丢失的方法（PLBM）或基于时间戳的方法（TBM）计算故障转移时间。建议使用TBM。
Measurement Units: milliseconds
测量单位：毫秒
Issues: None.
问题：没有。
See Also: Failover Failover Time Time-Based Loss Method (TBLM) Packet-Loss-Based Method (PLBM) Timestamp-Based Method (TBM)
另请参见：故障转移基于时间的丢失方法（TBLM）基于数据包丢失的方法（PLBM）基于时间戳的方法（TBM）
Definition: The amount of time it takes for Reversion to complete so that the Primary Path is restored as the Working Path.
定义：完成恢复所需的时间量，以便将主路径恢复为工作路径。
Discussion: Reversion Time can be calculated using the Time-Based Loss Method (TBLM), Packet-Loss-Based Method (PLBM), or Timestamp-Based Method (TBM). It is RECOMMENDED that the TBM is used.
讨论：可以使用基于时间的丢失方法（TBLM）、基于分组丢失的方法（PLBM）或基于时间戳的方法（TBM）来计算恢复时间。建议使用TBM。
Measurement Units: milliseconds
测量单位：毫秒
Issues: None.
问题：没有。
See Also: Reversion Primary Path Working Path Reversion Packet Loss
另请参见：恢复主路径工作路径恢复数据包丢失
Time-Based Loss Method (TBLM) Packet-Loss-Based Method (PLBM) Timestamp-Based Method (TBM)
基于时间的丢失方法（TBLM）基于分组丢失的方法（PLBM）基于时间戳的方法（TBM）
Definition: The amount of increased Forwarding Delay [4] resulting from data traffic traversing the Backup Path instead of the Primary Path.
定义：由于数据通信量通过备份路径而不是主路径而增加的转发延迟量[4]。
Discussion: Additive Backup Delay is calculated using Equation 1 as shown below:
讨论：使用方程式1计算附加备份延迟，如下所示：
(Equation 1) Additive Backup Delay = Forwarding Delay(Backup Path) - Forwarding Delay(Primary Path)
（方程式1）附加备份延迟=转发延迟（备份路径）-转发延迟（主路径）
Measurement Units: milliseconds
测量单位：毫秒
Issues: Additive Backup Latency may be a negative result. This is theoretically possible but could be indicative of a sub-optimum network configuration.
问题：附加备份延迟可能是负面结果。这在理论上是可能的，但可能表明网络配置处于次优状态。
See Also: Primary Path Backup Path Primary Path Latency Backup Path Latency
另请参见：主路径备份路径主路径延迟备份路径延迟
The following Methods may be assessed on a per-flow basis using at least 16 flows spread over the routing table (using more flows is better). Otherwise, the impact of a prefix-dependency in the implementation of a particular protection technology could be missed. However, the test designer must be aware of the number of packets per second sent to each prefix, as this establishes sampling of the path and the time resolution for measurement of Failover time on a per-flow basis.
可以使用路由表中至少16个流（使用更多的流更好）在每个流的基础上评估以下方法。否则，可能会忽略特定保护技术实现中前缀依赖性的影响。但是，测试设计者必须知道每秒发送到每个前缀的数据包的数量，因为这建立了路径的采样和时间分辨率，以便在每个流的基础上测量故障转移时间。
Definition: The method to calculate Failover Time (or Reversion Time) using a time scale on the Tester to measure the interval of Failover Packet Loss.
定义：使用测试仪上的时间刻度计算故障转移时间（或恢复时间）的方法，以测量故障转移数据包丢失的间隔。
Discussion: The Tester must provide statistics that show the duration of failure on a time scale based on occurrence of packet loss on a time scale. This is indicated by the duration of non-zero packet loss. The TBLM includes failure detection time and time for data traffic to begin traversing the Backup Path. Failover Time and Reversion Time are calculated using the TBLM as shown in Equation 2:
讨论：测试人员必须提供统计数据，根据时间尺度上发生的数据包丢失，在时间尺度上显示故障持续时间。这由非零数据包丢失的持续时间表示。TBLM包括故障检测时间和数据流量开始穿越备份路径的时间。故障转移时间和恢复时间使用TBLM计算，如等式2所示：
(Equation 2) (Equation 2a) TBLM Failover Time = Time(Failover) - Time(Failover Event)
（方程式2）（方程式2a）TBLM故障转移时间=时间（故障转移）-时间（故障转移事件）
(Equation 2b)
TBLM Reversion Time = Time(Reversion) - Time(Restoration)
(Equation 2b)
TBLM Reversion Time = Time(Reversion) - Time(Restoration)
Where
哪里
Time(Failover) = Time on the tester at the receipt of the first unimpaired packet at egress node after the backup path became the working path
时间（故障转移）=备份路径成为工作路径后，在出口节点接收到第一个未损坏数据包时测试仪上的时间
Time(Failover Event) = Time on the tester at the receipt of the last unimpaired packet at egress node on the primary path before failure
时间（故障转移事件）=故障发生前，测试仪在主路径上的出口节点接收到最后一个未损坏数据包时的时间
Measurement Units: milliseconds
测量单位：毫秒
Issues: None.
问题：没有。
See Also: Failover Packet-Loss-Based Method
另请参见：基于故障转移数据包丢失的方法
Definition: The method used to calculate Failover Time (or Reversion Time) from the amount of Failover Packet Loss.
定义：用于根据故障转移数据包丢失量计算故障转移时间（或恢复时间）的方法。
Discussion: PLBM includes failure detection time and time for data traffic to begin traversing the Backup Path. Failover Time can be calculated using PLBM from the amount of Failover Packet Loss as shown below in Equation 3. Note: If traffic is sent to more than 1 destination, PLBM gives the average loss over the measured destinations.
讨论：PLBM包括故障检测时间和数据流量开始穿越备份路径的时间。故障转移时间可以使用PLBM从故障转移数据包丢失量计算得出，如下式3所示。注意：如果流量发送到多个目的地，PLBM会给出测量目的地的平均损失。
(Equation 3) (Equation 3a) PLBM Failover Time = (Number of packets lost / Offered Load rate) * 1000)
（等式3）（等式3a）PLBM故障转移时间=（丢失的数据包数/提供的负载率）*1000）
(Equation 3b) PLBM Restoration Time = (Number of packets lost / Offered Load rate) * 1000)
（方程式3b）PLBM恢复时间=（丢失的数据包数/提供的负载率）*1000）
Units are packets/(packets/second) = seconds
Units are packets/(packets/second) = seconds
Measurement Units: milliseconds
测量单位：毫秒
Issues: None.
问题：没有。
See Also: Failover Time-Based Loss Method
另请参见：基于故障转移时间的丢失方法
Definition: The method to calculate Failover Time (or Reversion Time) using a time scale to quantify the interval between unimpaired packets arriving in the test stream.
定义：使用时间标度计算故障转移时间（或恢复时间）的方法，以量化到达测试流的未损坏数据包之间的间隔。
Discussion: The purpose of this method is to quantify the duration of failure or reversion on a time scale based on the observation of unimpaired packets. The TBM is calculated from Equation 2 with the values obtained from the timestamp in the packet payload, rather than from the Tester clock (which are used with the TBLM).
讨论：该方法的目的是基于对未损坏数据包的观察，在时间尺度上量化故障或恢复的持续时间。TBM由等式2计算，其值来自数据包有效载荷中的时间戳，而不是测试仪时钟（与TBLM一起使用）。
Unimpaired packets are normal packets that are not lost, reordered, or duplicated. A reordered packet is defined in Section 3.3 of [7]. A duplicate packet is defined in Section 3.3.5 of [4]. Unimpaired packets may be detected by checking a
未损坏的数据包是未丢失、重新排序或重复的正常数据包。[7]第3.3节定义了重新排序的数据包。[4]第3.3.5节定义了重复数据包。未损坏的数据包可以通过检查
sequence number in the payload, where the sequence number equals the next expected number for an unimpaired packet. A sequence gap or sequence reversal indicates impaired packets.
有效负载中的序列号，其中序列号等于未损坏数据包的下一个预期编号。序列间隔或序列反转表示数据包受损。
For calculating Failover Time, the TBM includes failure detection time and time for data traffic to begin traversing the Backup Path. For calculating Reversion Time, the TBM includes Reversion Time and time for data traffic to begin traversing the Primary Path.
为了计算故障切换时间，TBM包括故障检测时间和数据流量开始穿越备份路径的时间。为了计算恢复时间，TBM包括恢复时间和数据流量开始穿越主路径的时间。
Measurement Units: milliseconds
测量单位：毫秒
Issues: None.
问题：没有。
See Also: Failover Failover Time Reversion Reversion Time
另请参见：故障转移时间恢复恢复时间
Benchmarking activities as described in this memo are limited to technology characterization using controlled stimuli in a laboratory environment, with dedicated address space and the constraints specified in the sections above.
本备忘录中所述的基准测试活动仅限于在实验室环境中使用受控刺激进行技术表征，具有专用地址空间和上述章节中规定的约束条件。
The benchmarking network topology will be an independent test setup and MUST NOT be connected to devices that may forward the test traffic into a production network or misroute traffic to the test management network.
基准网络拓扑将是一个独立的测试设置，不得连接到可能将测试流量转发到生产网络或将流量错误路由到测试管理网络的设备。
Further, benchmarking is performed on a "black-box" basis, relying solely on measurements observable external to the DUT/SUT.
此外，基准测试是在“黑盒”的基础上进行的，仅依赖于DUT/SUT外部可观察到的测量。
Special capabilities SHOULD NOT exist in the DUT/SUT specifically for benchmarking purposes. Any implications for network security arising from the DUT/SUT SHOULD be identical in the lab and in production networks.
DUT/SUT中不应存在专门用于基准测试的特殊能力。DUT/SUT对网络安全的任何影响应在实验室和生产网络中相同。
[1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP 9, RFC 2026, October 1996.
[1] Bradner，S.，“互联网标准过程——第3版”，BCP 9，RFC 2026，1996年10月。
[2] Bradner, S., "Benchmarking Terminology for Network Interconnection Devices", RFC 1242, July 1991.
[2] Bradner，S.，“网络互连设备的基准术语”，RFC 1242，1991年7月。
[3] Mandeville, R., "Benchmarking Terminology for LAN Switching Devices", RFC 2285, February 1998.
[3] Mandeville，R.，“局域网交换设备的基准术语”，RFC 2285，1998年2月。
[4] Poretsky, S., Perser, J., Erramilli, S., and S. Khurana, "Terminology for Benchmarking Network-layer Traffic Control Mechanisms", RFC 4689, October 2006.
[4] Poretsky，S.，Perser，J.，Erramilli，S.，和S.Khurana，“基准网络层流量控制机制的术语”，RFC 4689，2006年10月。
[5] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[5] Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[6] Poretsky, S., Imhoff, B., and K. Michielsen, "Terminology for Benchmarking Link-State IGP Data Plane Route Convergence", RFC 6412, November 2011.
[6] Poretsky，S.，Imhoff，B.，和K.Michielsen，“链路状态IGP数据平面路由收敛基准术语”，RFC 6412，2011年11月。
[7] Morton, A., Ciavattone, L., Ramachandran, G., Shalunov, S., and J. Perser, "Packet Reordering Metrics", RFC 4737, November 2006.
[7] Morton，A.，Ciavattone，L.，Ramachandran，G.，Shalunov，S.，和J.Perser，“数据包重新排序度量”，RFC 4737，2006年11月。
[8] Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6", RFC 5798, March 2010.
[8] Nadas，S.，编辑，“IPv4和IPv6的虚拟路由器冗余协议（VRRP）第3版”，RFC 5798，2010年3月。
[9] Pan, P., Ed., Swallow, G., Ed., and A. Atlas, Ed., "Fast Reroute Extensions to RSVP-TE for LSP Tunnels", RFC 4090, May 2005.
[9] Pan，P.，Ed.，Swallow，G.，Ed.，和A.Atlas，Ed.，“LSP隧道RSVP-TE快速重路由扩展”，RFC 40902005年5月。
[10] Nichols, K., Blake, S., Baker, F., and D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998.
[10] Nichols，K.，Blake，S.，Baker，F.，和D.Black，“IPv4和IPv6头中区分服务字段（DS字段）的定义”，RFC 2474，1998年12月。
We would like thank the BMWG and particularly Al Morton and Curtis Villamizar for their reviews, comments, and contributions to this work.
我们要感谢BMWG，特别是Al Morton和Curtis Villamizar对这项工作的审查、评论和贡献。
Authors' Addresses
作者地址
Scott Poretsky Allot Communications 300 TradeCenter Woburn, MA 01801 USA Phone: + 1 508 309 2179 EMail: sporetsky@allot.com
Scott Poretsky Allot Communications 300美国马萨诸塞州沃本贸易中心01801电话：+1 508 309 2179电子邮件：sporetsky@allot.com
Rajiv Papneja Huawei Technologies 2330 Central Expressway Santa Clara, CA 95050 USA Phone: +1 571 926 8593 EMail: rajiv.papneja@huawei.com
Rajiv Papneya华为技术公司2330美国加利福尼亚州圣克拉拉中央高速公路95050电话：+1 571 926 8593电子邮件：Rajiv。papneja@huawei.com
Jay Karthik Cisco Systems 300 Beaver Brook Road Boxborough, MA 01719 USA Phone: +1 978 936 0533 EMail: jkarthik@cisco.com
Jay Karthik Cisco Systems美国马萨诸塞州Boxborough市比弗布鲁克路300号电话：+1 978 936 0533电子邮件：jkarthik@cisco.com
Samir Vapiwala Cisco System 300 Beaver Brook Road Boxborough, MA 01719 USA Phone: +1 978 936 1484 EMail: svapiwal@cisco.com
Samir Vapiwala思科系统美国马萨诸塞州Boxborough市比弗布鲁克路300号电话：+1 978 936 1484电子邮件：svapiwal@cisco.com