Internet Engineering Task Force (IETF) G. Mirsky
Request for Comments: 7189 Ericsson
Category: Standards Track March 2014
ISSN: 2070-1721
Internet Engineering Task Force (IETF) G. Mirsky
Request for Comments: 7189 Ericsson
Category: Standards Track March 2014
ISSN: 2070-1721
Virtual Circuit Connectivity Verification (VCCV) Capability Advertisement for MPLS Transport Profile (MPLS-TP)
MPLS传输配置文件（MPLS-TP）的虚拟电路连接验证（VCCV）能力公告
Abstract
摘要
This document specifies how signaling and selection processes for Pseudowire (PW) Virtual Circuit Connectivity Verification (VCCV) are modified to ensure backward compatibility and allow use of proactive Connectivity Verification (CV), Continuity Check (CC), and Remote Defect Indication (RDI) over MPLS Transport Profile (MPLS-TP) PWs. This document introduces four new CV types and, to accommodate them, a new VCCV Extended CV parameter for PW Interface Parameters Sub-TLV is defined.
本文件规定了如何修改伪线（PW）虚拟电路连接验证（VCCV）的信令和选择过程，以确保向后兼容性，并允许在MPLS传输配置文件（MPLS-TP）PWs上使用主动连接验证（CV）、连续性检查（CC）和远程缺陷指示（RDI）。本文档介绍了四种新的CV类型，为了适应它们，定义了PW接口参数子TLV的新VCCV扩展CV参数。
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/rfc7189.
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/rfc7189.
Copyright Notice
版权公告
Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2014 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. Conventions Used in This Document . . . . . . . . . . . . 2
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 2
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3
2. MPLS-TP CC-CV on Pseudowires . . . . . . . . . . . . . . . . 3
2.1. VCCV Extended CV Advertisement Sub-TLV . . . . . . . . . 3
2.2. MPLS-TP CC-CV Types . . . . . . . . . . . . . . . . . . . 3
2.3. MPLS-TP CC-CV Type Operation . . . . . . . . . . . . . . 4
2.4. CV Type Selection . . . . . . . . . . . . . . . . . . . . 4
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
3.1. VCCV Extended CV Types . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 7
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Conventions Used in This Document . . . . . . . . . . . . 2
1.1.1. Terminology . . . . . . . . . . . . . . . . . . . . . 2
1.1.2. Requirements Language . . . . . . . . . . . . . . . . 3
2. MPLS-TP CC-CV on Pseudowires . . . . . . . . . . . . . . . . 3
2.1. VCCV Extended CV Advertisement Sub-TLV . . . . . . . . . 3
2.2. MPLS-TP CC-CV Types . . . . . . . . . . . . . . . . . . . 3
2.3. MPLS-TP CC-CV Type Operation . . . . . . . . . . . . . . 4
2.4. CV Type Selection . . . . . . . . . . . . . . . . . . . . 4
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
3.1. VCCV Extended CV Types . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 6
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
6.1. Normative References . . . . . . . . . . . . . . . . . . 6
6.2. Informative References . . . . . . . . . . . . . . . . . 7
Proactive Connectivity Verification (CV), Continuity Check (CC), and Remote Defect Indication (RDI) for the MPLS Transport Profile [RFC6428] are applicable to all constructs of the MPLS-TP, including pseudowires (PWs). If the control plane is used to operate and manage PWs then the procedures defined in [RFC5085] and [RFC5885] should be used to select the proper type of Control Channel and the corresponding type of Connectivity Verification. This document specifies how signaling and selection processes are modified to ensure backward compatibility and allow use of proactive CV-CC-RDI over MPLS-TP PWs.
MPLS传输配置文件[RFC6428]的主动连接验证（CV）、连续性检查（CC）和远程缺陷指示（RDI）适用于MPLS-TP的所有结构，包括伪线（PWs）。如果控制平面用于操作和管理PWs，则应使用[RFC5085]和[RFC5885]中定义的程序选择适当类型的控制通道和相应类型的连接验证。本文件规定了如何修改信令和选择过程，以确保向后兼容性，并允许在MPLS-TP PWs上使用主动CV-CC-RDI。
BFD: Bidirectional Forwarding Detection
双向转发检测
CC: Continuity Check
连续性检查
CV: Connectivity Verification
连接验证
PE: Provider Edge
PE：提供程序边缘
VCCV: Virtual Circuit Connectivity Verification
虚拟电路连通性验证
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 [RFC2119].
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”应按照[RFC2119]中的说明进行解释。
PW VCCV can support several CV Types, and it can support an arbitrary combination of CV modes advertised in the CV Types field of the VCCV Interface Parameter sub-TLV [RFC4446] [RFC4447]. Currently, six types of CV have been defined for PW VCCV. This document introduces four new CV types and, to accommodate them, a new VCCV Extended CV parameter for the PW Interface Parameters Sub-TLV is defined.
PW VCCV可以支持多种CV类型，并且可以支持VCCV接口参数sub-TLV[RFC4446][RFC4447]的CV类型字段中公布的CV模式的任意组合。目前，已为PW VCCV定义了六种类型的CV。本文档介绍了四种新的CV类型，为了适应它们，定义了PW接口参数子TLV的新VCCV扩展CV参数。
The format of the VCCV Extended CV Advertisement is a TLV where the format is as follows:
VCCV扩展CV广告的格式为TLV，格式如下：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x19 | Length | CV Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type = 0x19 | Length | CV Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: VCCV Extended CV Parameter Format
图1:VCCV扩展CV参数格式
The Length field is the length of the sub-TLV, including type and the Length field itself. The minimum length is 4. It is recommended that extensions to the sub-TLV be done in 4-byte increments.
长度字段是子TLV的长度，包括类型和长度字段本身。最小长度为4。建议以4字节的增量对子TLV进行扩展。
The Reserved field MUST be set to zeroes on transmit and ignored on receive.
传输时保留字段必须设置为零，接收时忽略。
The CV Type field is a bitmask that lists types of CV monitoring that a PE is capable of supporting. The VCCV Extended CV parameter sub-TLV MUST appear in combination with the VCCV parameter sub-TLV. If the VCCV parameter sub-TLV is missing, then the VCCV Extended CV parameter sub-TLV SHOULD be ignored.
CV类型字段是一个位掩码，列出PE能够支持的CV监控类型。VCCV扩展CV参数sub TLV必须与VCCV参数sub TLV一起出现。如果缺少VCCV参数sub TLV，则应忽略VCCV扩展CV参数sub TLV。
[RFC6428] defines coordinated and independent modes of monitoring point-to-point bidirectional connection that can be applied to monitoring PWs. At the same time, [RFC6310] defines how BFD-based
[RFC6428]定义可应用于监测PWs的监测点对点双向连接的协调和独立模式。同时，[RFC6310]定义了如何基于BFD
Operations, Administration, and Maintenance (OAM) can map to the status of an Attachment Circuit. Thus, there could be four MPLS-TP CV types for each combination of mode and functionality:
操作、管理和维护（OAM）可以映射到连接回路的状态。因此，对于模式和功能的每个组合，可能有四种MPLS-TP CV类型：
+----------------+-------------------+------------------------------+
| Modes | Fault Detection | Fault Detection and Status |
| | Only | Signaling |
+----------------+-------------------+------------------------------+
| Independent | 0x01 | 0x02 |
| Mode | | |
| Coordinated | 0x04 | 0x08 |
| Mode | | |
+----------------+-------------------+------------------------------+
+----------------+-------------------+------------------------------+
| Modes | Fault Detection | Fault Detection and Status |
| | Only | Signaling |
+----------------+-------------------+------------------------------+
| Independent | 0x01 | 0x02 |
| Mode | | |
| Coordinated | 0x04 | 0x08 |
| Mode | | |
+----------------+-------------------+------------------------------+
Table 1: Bitmask Values for MPLS-TP CV Types
表1:MPLS-TP CV类型的位掩码值
According to [RFC6428], connectivity verification is part of MPLS-TP CC/CV operation that can be used with VCCV Control Channel Type 1 [RFC5085]. If VCCV Control Channel Type 1 is selected, then PEs MAY select one of the MPLS-TP CC-CV types as the VCCV CV mechanism to be used for this PW.
根据[RFC6428]，连接验证是MPLS-TP CC/CV操作的一部分，可与VCCV控制通道类型1[RFC5085]一起使用。如果选择VCCV控制信道类型1，则PEs可选择MPLS-TP CC-CV类型之一作为用于此PW的VCCV机制。
CV selection rules that have been defined in Section 7 of [RFC5085] and updated in Section 4 of [RFC5885] are augmented in this document.
本文件对[RFC5085]第7节中定义并在[RFC5885]第4节中更新的CV选择规则进行了补充。
If VCCV Control Channel Type 1 is chosen according to Section 7 of [RFC5085] and a common set of proactive CV types that are advertised by both PEs includes MPLS-TP CC-CV types and some BFD CV types, then MPLS-TP CC-CV takes precedence over any type of BFD CV. If multiple MPLS-TP CV types are advertised by both PEs, then the following list (ordered by descending priority) is used:
如果根据[RFC5085]第7节选择VCCV控制信道类型1，并且两个PEs公布的一组常见主动CV类型包括MPLS-TP CC-CV类型和一些BFD CV类型，则MPLS-TP CC-CV优先于任何类型的BFD CV。如果两个PE都公布了多个MPLS-TP CV类型，则使用以下列表（按优先级降序排列）：
1. 0x08 - Coordinated mode for PW Fault Detection and AC/PW Fault Status Signaling
1. 0x08-PW故障检测和AC/PW故障状态信号的协调模式
2. 0x04 - Coordinated mode for PW Fault Detection only
2. 0x04-仅用于PW故障检测的协调模式
3. 0x02 - Independent mode for PW Fault Detection and AC/PW Fault Status Signaling
3. 0x02-PW故障检测和AC/PW故障状态信号的独立模式
4. 0x01 - Independent mode for PW Fault Detection only
4. 0x01-仅用于PW故障检测的独立模式
The PW Interface Parameters Sub-TLV registry is defined in [RFC4446].
PW接口参数子TLV注册表在[RFC4446]中定义。
IANA has reserved a new PW Interface Parameters Sub-TLV type as follows:
IANA保留了一个新的PW接口参数子TLV类型，如下所示：
+-----------+----------+----------------------------+---------------+
| Parameter | Length | Description | Reference |
| ID | | | |
+-----------+----------+----------------------------+---------------+
| 0x19 | variable | VCCV Extended CV Parameter | This document |
+-----------+----------+----------------------------+---------------+
+-----------+----------+----------------------------+---------------+
| Parameter | Length | Description | Reference |
| ID | | | |
+-----------+----------+----------------------------+---------------+
| 0x19 | variable | VCCV Extended CV Parameter | This document |
+-----------+----------+----------------------------+---------------+
Table 2: New PW Interface Parameters Sub-TLV
表2：新PW接口参数子TLV
IANA has set up a registry of VCCV Extended CV Types. These are 8-bit values. Extended CV Type values 0x01, 0x02, 0x04, and 0x08 are specified in Section 2.2 of this document. The remaining values (0x10 through 0x80) are to be assigned by IANA using the "IETF Review" policy defined in [RFC5226]. A VCCV Extended Connectivity Verification Type description and a reference to an RFC approved by the IESG are required for any assignment from this registry.
IANA已经建立了VCCV扩展CV类型的注册表。这些是8位值。本文件第2.2节规定了扩展CV类型值0x01、0x02、0x04和0x08。IANA将使用[RFC5226]中定义的“IETF审查”策略分配剩余值（0x10至0x80）。此注册表中的任何分配都需要VCCV扩展连接验证类型说明和IESG批准的RFC参考。
+--------------+----------------------------------------------------+
| Bit(Value) | Description |
+--------------+----------------------------------------------------+
| Bit 0 (0x01) | Independent mode for PW Fault Detection only |
| Bit 1 (0x02) | Independent mode for PW Fault Detection and AC/PW |
| | Fault Status Signaling |
| Bit 2 (0x04) | Coordinated mode for PW Fault Detection only |
| Bit 3 (0x08) | Coordinated mode for PW Fault Detection and AC/PW |
| | Fault Status Signaling |
| Bit 4 (0x10) | Unassigned |
| Bit 5 (0x20) | Unassigned |
| Bit 6 (0x40) | Unassigned |
| Bit 7 (0x80) | Unassigned |
+--------------+----------------------------------------------------+
+--------------+----------------------------------------------------+
| Bit(Value) | Description |
+--------------+----------------------------------------------------+
| Bit 0 (0x01) | Independent mode for PW Fault Detection only |
| Bit 1 (0x02) | Independent mode for PW Fault Detection and AC/PW |
| | Fault Status Signaling |
| Bit 2 (0x04) | Coordinated mode for PW Fault Detection only |
| Bit 3 (0x08) | Coordinated mode for PW Fault Detection and AC/PW |
| | Fault Status Signaling |
| Bit 4 (0x10) | Unassigned |
| Bit 5 (0x20) | Unassigned |
| Bit 6 (0x40) | Unassigned |
| Bit 7 (0x80) | Unassigned |
+--------------+----------------------------------------------------+
Table 3: VCCV Extended Connectivity Verification (CV) Types
表3:VCCV扩展连接验证（CV）类型
Routers that implement the additional CV Type defined herein are subject to the same security considerations as defined in [RFC5085], [RFC5880], [RFC5881], and [RFC6428]. This specification does not raise any additional security issues beyond those.
实现本文定义的附加CV类型的路由器受到与[RFC5085]、[RFC5880]、[RFC5881]和[RFC6428]中定义的相同安全考虑的约束。除此之外，本规范不会提出任何其他安全问题。
The author gratefully acknowledges the thoughtful review, comments, and explanations provided by Dave Allan and Carlos Pignataro.
作者感谢Dave Allan和Carlos Pignataro提供的深思熟虑的评论、评论和解释。
[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。
[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)", BCP 116, RFC 4446, April 2006.
[RFC4446]Martini，L.，“伪线边到边仿真（PWE3）的IANA分配”，BCP 116，RFC 4446，2006年4月。
[RFC4447] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006.
[RFC4447]Martini，L.，Rosen，E.，El Aawar，N.，Smith，T.，和G.Heron，“使用标签分发协议（LDP）的伪线设置和维护”，RFC 4447，2006年4月。
[RFC5085] Nadeau, T. and C. Pignataro, "Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires", RFC 5085, December 2007.
[RFC5085]Nadeau，T.和C.Pignataro，“伪线虚拟电路连接验证（VCCV）：伪线的控制通道”，RFC 5085，2007年12月。
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD)", RFC 5880, June 2010.
[RFC5880]Katz，D.和D.Ward，“双向转发检测（BFD）”，RFC 58802010年6月。
[RFC5881] Katz, D. and D. Ward, "Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, June 2010.
[RFC5881]Katz，D.和D.Ward，“IPv4和IPv6（单跳）的双向转发检测（BFD）”，RFC 58812010年6月。
[RFC5885] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)", RFC 5885, June 2010.
[RFC5885]Nadeau，T.和C.Pignataro，“伪线虚拟电路连接验证（VCCV）的双向转发检测（BFD）”，RFC 58852010年6月。
[RFC6310] Aissaoui, M., Busschbach, P., Martini, L., Morrow, M., Nadeau, T., and Y(J). Stein, "Pseudowire (PW) Operations, Administration, and Maintenance (OAM) Message Mapping", RFC 6310, July 2011.
[RFC6310]Aissaoui，M.，Busschbach，P.，Martini，L.，Morrow，M.，Nadeau，T.，和Y（J）。Stein，“伪线（PW）操作、管理和维护（OAM）消息映射”，RFC63102011年7月。
[RFC6428] Allan, D., Swallow Ed. , G., and J. Drake Ed. , "Proactive Connectivity Verification, Continuity Check, and Remote Defect Indication for the MPLS Transport Profile", RFC 6428, November 2011.
[RFC6428]Allan，D.，Swallow Ed.，G.，和J.Drake Ed.，“MPLS传输配置文件的主动连接验证、连续性检查和远程缺陷指示”，RFC 6428，2011年11月。
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.
[RFC5226]Narten，T.和H.Alvestrand，“在RFCs中编写IANA注意事项部分的指南”，BCP 26，RFC 5226，2008年5月。
Author's Address
作者地址
Greg Mirsky Ericsson
格雷格·米尔斯基·爱立信
EMail: gregory.mirsky@ericsson.com
EMail: gregory.mirsky@ericsson.com