Internet Engineering Task Force (IETF) P. Jain, Ed.
Request for Comments: 8339 Cisco Systems, Inc.
Category: Standards Track S. Boutros
ISSN: 2070-1721 VMWare, Inc.
S. Aldrin
Google Inc.
March 2018
Internet Engineering Task Force (IETF) P. Jain, Ed.
Request for Comments: 8339 Cisco Systems, Inc.
Category: Standards Track S. Boutros
ISSN: 2070-1721 VMWare, Inc.
S. Aldrin
Google Inc.
March 2018
Definition of P2MP PW TLV for Label Switched Path (LSP) Ping Mechanisms
标签交换路径（LSP）Ping机制的P2MP PW TLV定义
Abstract
摘要
Label Switched Path (LSP) Ping is a widely deployed Operation, Administration, and Maintenance (OAM) mechanism in MPLS networks. This document describes a mechanism to verify connectivity of Point-to-Multipoint (P2MP) Pseudowires (PWs) using LSP Ping.
标签交换路径（LSP）Ping是MPLS网络中广泛部署的操作、管理和维护（OAM）机制。本文档描述了一种使用LSP Ping验证点对多点（P2MP）伪线（PWs）连接的机制。
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 7841.
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 7841第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8339.
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https://www.rfc-editor.org/info/rfc8339.
Copyright Notice
版权公告
Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2018 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 (https://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(https://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
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Specification of Requirements . . . . . . . . . . . . . . 3
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
3. Identifying a P2MP PW . . . . . . . . . . . . . . . . . . . . 5
3.1. P2MP Pseudowire Sub-TLV . . . . . . . . . . . . . . . . . 5
4. Encapsulation of OAM Ping Packets . . . . . . . . . . . . . . 6
5. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Controlling Echo Responses . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Specification of Requirements . . . . . . . . . . . . . . 3
2.2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . 4
3. Identifying a P2MP PW . . . . . . . . . . . . . . . . . . . . 5
3.1. P2MP Pseudowire Sub-TLV . . . . . . . . . . . . . . . . . 5
4. Encapsulation of OAM Ping Packets . . . . . . . . . . . . . . 6
5. Operations . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Controlling Echo Responses . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 8
9.1. Normative References . . . . . . . . . . . . . . . . . . 8
9.2. Informative References . . . . . . . . . . . . . . . . . 9
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 10
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
A Point-to-Multipoint (P2MP) Pseudowire (PW) emulates the essential attributes of a unidirectional P2MP Telecommunications service such as P2MP ATM over a Public Switched Network (PSN). Requirements for P2MP PWs are described in [RFC7338]. P2MP PWs are carried over a P2MP MPLS LSP. The procedures for P2MP PW signaling using BGP are described in [RFC7117]; LDP for single segment P2MP PWs is described in [RFC8338]. Many P2MP PWs can share the same P2MP MPLS LSP; this arrangement is called an "Aggregate P2MP Tree". An Aggregate P2MP Tree requires an upstream-assigned label so that on the Leaf PE (L-PE), the traffic can be associated with a Virtual Private Network (VPN) or a Virtual Private LAN Service (VPLS) instance. When a P2MP MPLS LSP carries only one VPN or VPLS service instance, the arrangement is called an "Inclusive P2MP Tree". For an Inclusive P2MP Tree, the P2MP MPLS LSP label itself can uniquely identify the VPN or VPLS service being carried over the P2MP MPLS LSP. The P2MP MPLS LSP can also be used in the Selective P2MP Tree arrangement to carry multicast traffic. In a Selective P2MP Tree arrangement, traffic to each multicast group in a VPN or VPLS instance is carried by a separate unique P2MP LSP. In an Aggregate Selective P2MP Tree arrangement, traffic to a set of multicast groups from different VPN or VPLS instances is carried over the same shared P2MP LSP.
点对多点（P2MP）伪线（PW）模拟单向P2MP电信服务的基本属性，例如公共交换网络（PSN）上的P2MP ATM。[RFC7338]中描述了P2MP PWs的要求。P2MP PW通过P2MP MPLS LSP传输。[RFC7117]中描述了使用BGP的P2MP PW信令程序；[RFC8338]中描述了单段P2MP PWs的LDP。多个P2MP PW可以共享同一个P2MP MPLS LSP；这种安排称为“聚合P2MP树”。聚合P2MP树需要上游分配的标签，以便在叶PE（L-PE）上，流量可以与虚拟专用网络（VPN）或虚拟专用LAN服务（VPLS）实例相关联。当P2MP MPLS LSP仅承载一个VPN或VPLS服务实例时，这种安排称为“包含P2MP树”。对于包含性P2MP树，P2MP MPLS LSP标签本身可以唯一标识通过P2MP MPLS LSP承载的VPN或VPLS服务。P2MP MPLS LSP还可用于选择性P2MP树安排中，以承载多播业务。在选择性P2MP树安排中，VPN或VPLS实例中每个多播组的流量由单独的唯一P2MP LSP承载。在聚合选择性P2MP树安排中，来自不同VPN或VPLS实例的到一组多播组的流量通过相同的共享P2MP LSP进行传输。
The P2MP MPLS LSPs are setup using either P2MP RSVP-TE [RFC4875] or Multipoint LDP (mDLP) [RFC6388]. Mechanisms for fault detection and isolation for data-plane failures for P2MP MPLS LSPs are specified in [RFC6425]. This document describes a mechanism to detect data-plane failures for P2MP PW carried over P2MP MPLS LSPs.
P2MP MPLS LSP使用P2MP RSVP-TE[RFC4875]或多点LDP（mDLP）[RFC6388]进行设置。[RFC6425]中规定了P2MP MPLS LSP数据平面故障的故障检测和隔离机制。本文档描述了检测P2MP MPLS LSP上携带的P2MP PW数据平面故障的机制。
This document defines a new P2MP Pseudowire sub-TLV for the Target Forwarding Equivalence Class (FEC) Stack for P2MP PWs. The P2MP Pseudowire sub-TLV is added in the Target FEC Stack TLV by the originator of the echo request at the Root PE (R-PE) to inform the receiver at the Leaf PE (L-PE) of the P2MP PW being tested.
本文档为P2MP PWs的目标转发等价类（FEC）堆栈定义了一个新的P2MP伪线子TLV。P2MP伪线子TLV由根PE（R-PE）处回声请求的发起人添加到目标FEC堆栈TLV中，以通知叶PE（L-PE）处的接收器正在测试的P2MP PW。
Support for multi-segment PWs is out of scope of this document.
对多段PWs的支持超出了本文档的范围。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”在所有大写字母出现时（如图所示）应按照BCP 14[RFC2119][RFC8174]所述进行解释。
ACH: Associated Channel Header
ACH：关联通道头
AGI: Attachment Group Identifier
AGI:附件组标识符
ATM: Asynchronous Transfer Mode
异步传输模式
CE: Customer Edge
行政长官：顾客优势
FEC: Forwarding Equivalence Class
转发等价类
GAL: Generic Associated Channel Label
GAL：通用关联通道标签
LDP: Label Distribution Protocol
标签分发协议
L-PE: Leaf PE (one of many destinations of the P2MP MPLS LSP, i.e., egress PE)
L-PE：叶PE（P2MP MPLS LSP的许多目的地之一，即出口PE）
LSP: Label Switched Path
标签交换路径
LSR: Label Switching Router
标签交换路由器
mLDP: Multipoint LDP
多点LDP
MPLS-OAM: MPLS Operations, Administration, and Maintenance
MPLS-OAM：MPLS操作、管理和维护
P2MP: Point-to-Multipoint
P2MP：点对多点
P2MP-PW: Point-to-Multipoint Pseudowire
P2MP-PW：点对多点伪线
PE: Provider Edge
PE：提供程序边缘
PSN: Public Switched Network
公共交换网
PW: Pseudowire
伪线
R-PE: Root PE (ingress PE, PE initiating P2MP PW setup)
R-PE：根PE（入口PE，PE启动P2MP PW设置）
RSVP: Resource Reservation Protocol
资源预留协议
TE: Traffic Engineering
交通工程
TLV: Type, Length, Value
TLV：类型、长度、值
VPLS: Virtual Private LAN Service
虚拟专用局域网服务
This document introduces a new LSP Ping Target FEC Stack sub-TLV, the P2MP Pseudowire sub-TLV, to identify the P2MP PW under test at the P2MP Leaf PE (L-PE).
本文档介绍了一种新的LSP Ping目标FEC堆栈子TLV，即P2MP伪线子TLV，用于识别P2MP叶PE（L-PE）处测试的P2MP PW。
The P2MP Pseudowire sub-TLV has the format shown in Figure 1. This TLV is included in the echo request sent over P2MP PW by the originator of the request.
P2MP伪线子TLV的格式如图1所示。该TLV包含在请求发起人通过P2MP PW发送的回显请求中。
The Attachment Group Identifier (AGI), as described in Section 3.4.2 of [RFC4446], in P2MP Pseudowire sub-TLV identifies the VPLS instance. The Originating Router's IP address is the IPv4 or IPv6 address of the P2MP PW root. The address family of the IP address is determined by the IP Addr Len field.
如[RFC4446]第3.4.2节所述，P2MP伪线子TLV中的附件组标识符（AGI）标识VPLS实例。发起路由器的IP地址是P2MP PW根的IPv4或IPv6地址。IP地址的地址系列由IP Addr Len字段确定。
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AGI Type | AGI Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
~ AGI Value ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Addr Len | |
+-+-+-+-+-+-+-+ |
~ Originating Routers IP Addr ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| AGI Type | AGI Length | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
~ AGI Value ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| IP Addr Len | |
+-+-+-+-+-+-+-+ |
~ Originating Routers IP Addr ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: P2MP Pseudowire Sub-TLV Format
图1:P2MP伪线子TLV格式
For Inclusive and Selective P2MP Trees, the echo request is sent using the P2MP MPLS LSP label.
对于包含和选择性P2MP树，使用P2MP MPLS LSP标签发送回显请求。
For Aggregate Inclusive and Aggregate Selective P2MP Trees, the echo request is sent using a label stack of [P2MP MPLS LSP label, upstream assigned P2MP PW label]. The P2MP MPLS LSP label is the outer label and the upstream assigned P2MP PW label is the inner label.
对于聚合包容性和聚合选择性P2MP树，使用标签堆栈[P2MP MPLS LSP label，上游分配的P2MP PW label]发送回显请求。P2MP MPLS LSP标签是外部标签，上游分配的P2MP PW标签是内部标签。
The LSP Ping echo request packet is encapsulated with the MPLS label stack as described in previous sections, followed by one of the two encapsulation options:
如前几节所述，LSP Ping echo请求数据包由MPLS标签堆栈封装，然后是两个封装选项之一：
o GAL [RFC6426] followed by an IPv4 (0x0021) or IPv6 (0x0057) type Associated Channel Header (ACH) [RFC4385]
o GAL[RFC6426]后跟IPv4（0x0021）或IPv6（0x0057）类型的关联信道头（ACH）[RFC4385]
o PW ACH [RFC4385]
o PW ACH[RFC4385]
To ensure interoperability, implementations of this document MUST support both encapsulations.
为了确保互操作性，本文档的实现必须支持这两种封装。
In this section, we explain the operation of the LSP Ping over a P2MP PW. Figure 2 shows a P2MP PW PW1 setup from Root PE R-PE1, to Leaf PEs (L-PE2, L-PE3, and L-PE4). The transport LSP associated with the P2MP PW1 can be mLDP P2MP MPLS LSP or P2MP TE tunnel.
在本节中，我们将解释P2MP PW上LSP Ping的操作。图2显示了从根PE R-PE1到叶PE（L-PE2、L-PE3和L-PE4）的P2MP PW PW1设置。与P2MP PW1相关联的传输LSP可以是mLDP P2MP MPLS LSP或P2MP TE隧道。
|<--------------P2MP PW---------------->|
Native | | Native
Service | |<--PSN1->| |<--PSN2->| | Service
(AC) V V V V V V (AC)
| +-----+ +------+ +------+ |
| | | | P1 |=========|L-PE2 |AC3 | +---+
| | | | .......PW1.........>|-------->|CE3|
| |R-PE1|=========| . |=========| | | +---+
| | .......PW1........ | +------+ |
| | . |=========| . | +------+ |
| | . | | . |=========|L-PE3 |AC4 | +---+
+---+ |AC1 | . | | .......PW1.........>|-------->|CE4|
|CE1|------->|... | | |=========| | | +---+
+---+ | | . | +------+ +------+ |
| | . | +------+ +------+ |
| | . |=========| P2 |=========|L-PE4 |AC5 | +---+
| | .......PW1..............PW1.........>|-------->|CE5|
| | |=========| |=========| | | +---+
| +-----+ +------+ +------+ |
|<--------------P2MP PW---------------->|
Native | | Native
Service | |<--PSN1->| |<--PSN2->| | Service
(AC) V V V V V V (AC)
| +-----+ +------+ +------+ |
| | | | P1 |=========|L-PE2 |AC3 | +---+
| | | | .......PW1.........>|-------->|CE3|
| |R-PE1|=========| . |=========| | | +---+
| | .......PW1........ | +------+ |
| | . |=========| . | +------+ |
| | . | | . |=========|L-PE3 |AC4 | +---+
+---+ |AC1 | . | | .......PW1.........>|-------->|CE4|
|CE1|------->|... | | |=========| | | +---+
+---+ | | . | +------+ +------+ |
| | . | +------+ +------+ |
| | . |=========| P2 |=========|L-PE4 |AC5 | +---+
| | .......PW1..............PW1.........>|-------->|CE5|
| | |=========| |=========| | | +---+
| +-----+ +------+ +------+ |
Figure 2: P2MP PW
图2:P2MP PW
When an operator wants to perform a connectivity check for the P2MP PW1, the operator initiates an LSP Ping echo request from Root PE R-PE1, with the Target FEC Stack TLV containing the P2MP Pseudowire sub-TLV in the echo request packet. For an Inclusive P2MP Tree arrangement, the echo request packet is sent over the P2MP MPLS LSP with one of the following two encapsulation options:
当运营商希望对P2MP PW1执行连接检查时，运营商从根PE R-PE1发起LSP Ping回显请求，目标FEC堆栈TLV包含回显请求包中的P2MP伪线子TLV。对于包含式P2MP树安排，回送请求数据包通过P2MP MPLS LSP发送，具有以下两种封装选项之一：
o {P2MP LSP label, GAL} MPLS label stack and IPv4 or IPv6 ACH.
o {P2MP LSP标签，GAL}MPLS标签堆栈和IPv4或IPv6 ACH。
o {P2MP LSP label} MPLS label stack and PW ACH.
o {P2MP LSP label}MPLS标签堆栈和PW ACH。
For an Aggregate Inclusive Tree arrangement, the echo request packet is sent over the P2MP MPLS LSP with one of the following two encapsulation options:
对于聚合包含树安排，使用以下两种封装选项之一通过P2MP MPLS LSP发送回显请求数据包：
o {P2MP LSP label, P2MP PW upstream assigned label, GAL} MPLS label stack and IPv4 or IPv6 ACH.
o {P2MP LSP标签、P2MP PW上游分配标签、GAL}MPLS标签堆栈和IPv4或IPv6 ACH。
o {P2MP LSP label, P2MP PW upstream assigned label} MPLS label stack and PW ACH.
o {P2MP LSP标签，P2MP PW上游分配标签}MPLS标签堆栈和PW ACH。
The intermediate P routers do MPLS label swap and replication based on the incoming MPLS LSP label. Once the echo request packet reaches L-PEs, L-PEs use the GAL and the IPv4/IPv6 ACH Channel header or PW ACH as the case may be, to determine that the packet is an OAM Packet. The L-PEs process the packet and perform checks for the P2MP Pseudowire sub-TLV present in the Target FEC Stack TLV as described in Section 4.4 in [RFC8029] and respond according to the processing rules in that document.
中间路由器根据传入的MPLS LSP标签进行MPLS标签交换和复制。一旦echo请求分组到达L-PEs，L-PEs使用GAL和IPv4/IPv6 ACH信道报头或PW ACH（视情况而定）来确定该分组是OAM分组。L-PEs处理数据包，并按照[RFC8029]第4.4节所述检查目标FEC堆栈TLV中存在的P2MP伪线子TLV，并根据该文档中的处理规则进行响应。
The procedures described in [RFC6425] for preventing congestion of Echo Responses (Echo Jitter TLV in Section 3.3 of [RFC6425]) and limiting the echo reply to a single L-PE (Node Address P2MP Responder Identifier TLV in Section 3.2 of [RFC6425]) should be applied to P2MP PW LSP Ping.
[RFC6425]中描述的用于防止回波响应拥塞（第[RFC6425]第3.3节中的回波抖动TLV）和将回波响应限制为单个L-PE（第[RFC6425]第3.2节中的节点地址P2MP响应器标识符TLV）的程序应适用于P2MP PW LSP Ping。
The proposal introduced in this document does not introduce any new security considerations beyond those that already apply to [RFC6425].
本文件中介绍的提案未引入任何新的安全注意事项，超出了[RFC6425]已经适用的安全注意事项。
This document defines a new sub-TLV type included in the Target FEC Stack TLV (TLV Type 1) [RFC8029] in LSP Ping.
本文档定义了LSP Ping中目标FEC堆栈TLV（TLV类型1）[RFC8029]中包含的新子TLV类型。
IANA has assigned the following sub-TLV type value from the "Sub-TLVs for TLV Types 1, 16, and 21" sub-registry within the "Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) Ping Parameters" registry:
IANA已从“多协议标签交换（MPLS）标签交换路径（LSP）Ping参数”注册表中的“TLV类型1、16和21的子TLV”子注册表中分配了以下子TLV类型值：
37 P2MP Pseudowire
37 P2MP假丝
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<https://www.rfc-editor.org/info/rfc2119>.
[RFC4385] Bryant, S., Swallow, G., Martini, L., and D. McPherson, "Pseudowire Emulation Edge-to-Edge (PWE3) Control Word for Use over an MPLS PSN", RFC 4385, DOI 10.17487/RFC4385, February 2006, <https://www.rfc-editor.org/info/rfc4385>.
[RFC4385]Bryant，S.，Swallow，G.，Martini，L.，和D.McPherson，“用于MPLS PSN的伪线仿真边到边（PWE3）控制字”，RFC 4385，DOI 10.17487/RFC4385，2006年2月<https://www.rfc-editor.org/info/rfc4385>.
[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)", BCP 116, RFC 4446, DOI 10.17487/RFC4446, April 2006, <https://www.rfc-editor.org/info/rfc4446>.
[RFC4446]Martini，L.，“伪线边到边仿真（PWE3）的IANA分配”，BCP 116，RFC 4446，DOI 10.17487/RFC4446，2006年4月<https://www.rfc-editor.org/info/rfc4446>.
[RFC6425] Saxena, S., Ed., Swallow, G., Ali, Z., Farrel, A., Yasukawa, S., and T. Nadeau, "Detecting Data-Plane Failures in Point-to-Multipoint MPLS - Extensions to LSP Ping", RFC 6425, DOI 10.17487/RFC6425, November 2011, <https://www.rfc-editor.org/info/rfc6425>.
[RFC6425]Saxena，S.，Ed.，Swallow，G.，Ali，Z.，Farrel，A.，Yasukawa，S.，和T.Nadeau，“检测点对多点MPLS中的数据平面故障-LSP Ping扩展”，RFC 6425，DOI 10.17487/RFC6425，2011年11月<https://www.rfc-editor.org/info/rfc6425>.
[RFC6426] Gray, E., Bahadur, N., Boutros, S., and R. Aggarwal, "MPLS On-Demand Connectivity Verification and Route Tracing", RFC 6426, DOI 10.17487/RFC6426, November 2011, <https://www.rfc-editor.org/info/rfc6426>.
[RFC6426]Gray，E.，Bahadur，N.，Boutros，S.，和R.Aggarwal，“MPLS按需连接验证和路由跟踪”，RFC 6426，DOI 10.17487/RFC6426，2011年11月<https://www.rfc-editor.org/info/rfc6426>.
[RFC7117] Aggarwal, R., Ed., Kamite, Y., Fang, L., Rekhter, Y., and C. Kodeboniya, "Multicast in Virtual Private LAN Service (VPLS)", RFC 7117, DOI 10.17487/RFC7117, February 2014, <https://www.rfc-editor.org/info/rfc7117>.
[RFC7117]Aggarwal，R.，Ed.，Kamite，Y.，Fang，L.，Rekhter，Y.，和C.Kodeboniya，“虚拟专用局域网服务（VPLS）中的多播”，RFC 7117，DOI 10.17487/RFC71172014年2月<https://www.rfc-editor.org/info/rfc7117>.
[RFC8029] Kompella, K., Swallow, G., Pignataro, C., Ed., Kumar, N., Aldrin, S., and M. Chen, "Detecting Multiprotocol Label Switched (MPLS) Data-Plane Failures", RFC 8029, DOI 10.17487/RFC8029, March 2017, <https://www.rfc-editor.org/info/rfc8029>.
[RFC8029]Kompella，K.，Swallow，G.，Pignataro，C.，Ed.，Kumar，N.，Aldrin，S.，和M.Chen，“检测多协议标签交换（MPLS）数据平面故障”，RFC 8029，DOI 10.17487/RFC8029，2017年3月<https://www.rfc-editor.org/info/rfc8029>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8174]Leiba，B.，“RFC 2119关键词中大写与小写的歧义”，BCP 14，RFC 8174，DOI 10.17487/RFC8174，2017年5月<https://www.rfc-editor.org/info/rfc8174>.
[RFC8338] Boutros, S., Ed. and S. Sivabalan, Ed., "Signaling Root-Initiated Point-to-Multipoint Pseudowire Using LDP", RFC 8338, DOI 10.17487/RFC8338, March 2018, <https://www.rfc-editor.org/info/rfc8338>.
[RFC8338]Boutros，S.，Ed.和S.Sivabalan，Ed.，“使用LDP发送根发起的点对多点伪线”，RFC 8338，DOI 10.17487/RFC8338，2018年3月<https://www.rfc-editor.org/info/rfc8338>.
[RFC4875] Aggarwal, R., Ed., Papadimitriou, D., Ed., and S. Yasukawa, Ed., "Extensions to Resource Reservation Protocol - Traffic Engineering (RSVP-TE) for Point-to-Multipoint TE Label Switched Paths (LSPs)", RFC 4875, DOI 10.17487/RFC4875, May 2007, <https://www.rfc-editor.org/info/rfc4875>.
[RFC4875]Aggarwal，R.，Ed.，Papadimitriou，D.，Ed.，和S.Yasukawa，Ed.，“资源预留协议的扩展-点对多点TE标签交换路径（LSP）的流量工程（RSVP-TE）”，RFC 4875，DOI 10.17487/RFC4875，2007年5月<https://www.rfc-editor.org/info/rfc4875>.
[RFC6388] Wijnands, IJ., Ed., Minei, I., Ed., Kompella, K., and B. Thomas, "Label Distribution Protocol Extensions for Point-to-Multipoint and Multipoint-to-Multipoint Label Switched Paths", RFC 6388, DOI 10.17487/RFC6388, November 2011, <https://www.rfc-editor.org/info/rfc6388>.
[RFC6388]Wijnands，IJ.，Ed.，Minei，I.，Ed.，Kompella，K.和B.Thomas，“点对多点和多点对多点标签交换路径的标签分发协议扩展”，RFC 6388，DOI 10.17487/RFC6388，2011年11月<https://www.rfc-editor.org/info/rfc6388>.
[RFC7338] Jounay, F., Ed., Kamite, Y., Ed., Heron, G., and M. Bocci, "Requirements and Framework for Point-to-Multipoint Pseudowires over MPLS Packet Switched Networks", RFC 7338, DOI 10.17487/RFC7338, September 2014, <https://www.rfc-editor.org/info/rfc7338>.
[RFC7338]Jounay，F.，Ed.，Kamite，Y.，Ed.，Heron，G.，和M.Bocci，“MPLS分组交换网络上点对多点伪线的要求和框架”，RFC 7338，DOI 10.17487/RFC7338，2014年9月<https://www.rfc-editor.org/info/rfc7338>.
Acknowledgments
致谢
The authors would like to thank Shaleen Saxena, Greg Mirsky, Andrew G. Malis, and Danny Prairie for their valuable input and comments.
作者要感谢Shaleen Saxena、Greg Mirsky、Andrew G.Malis和Danny Prairie的宝贵投入和评论。
Authors' Addresses
作者地址
Parag Jain (editor) Cisco Systems, Inc. 2000 Innovation Drive Kanata, ON K2K-3E8 Canada
Parag Jain（编辑）思科系统公司2000年创新大道卡纳塔，位于加拿大K2K-3E8
Email: paragj@cisco.com
Email: paragj@cisco.com
Sami Boutros VMWare, Inc. United States of America
Sami Boutros VMWare，Inc.美利坚合众国
Email: sboutros@vmware.com
Email: sboutros@vmware.com
Sam Aldrin Google Inc. United States of America
山姆·奥尔德林谷歌公司美利坚合众国
Email: aldrin.ietf@gmail.com
Email: aldrin.ietf@gmail.com