Internet Engineering Task Force (IETF) K. Raza
Request for Comments: 6667 S. Boutros
Category: Standards Track C. Pignataro
ISSN: 2070-1721 Cisco Systems
July 2012
Internet Engineering Task Force (IETF) K. Raza
Request for Comments: 6667 S. Boutros
Category: Standards Track C. Pignataro
ISSN: 2070-1721 Cisco Systems
July 2012
LDP 'Typed Wildcard' Forwarding Equivalence Class (FEC) for PWid and Generalized PWid FEC Elements
PWid和广义PWid FEC元素的LDP“类型通配符”转发等价类（FEC）
Abstract
摘要
The "Typed Wildcard Forwarding Equivalence Class (FEC) Element" defines an extension to the Label Distribution Protocol (LDP) that can be used when requesting, withdrawing, or releasing all label bindings for a given FEC Element type is desired. However, a Typed Wildcard FEC Element must be individually defined for each FEC Element type. This specification defines the Typed Wildcard FEC Elements for the Pseudowire Identifier (PWid) (0x80) and Generalized PWid (0x81) FEC Element types.
“类型化通配符转发等价类（FEC）元素”定义了标签分发协议（LDP）的扩展，当需要请求、撤消或释放给定FEC元素类型的所有标签绑定时，可以使用该扩展。但是，必须为每个FEC元素类型单独定义一个类型化通配符FEC元素。本规范定义了伪线标识符（PWid）（0x80）和广义PWid（0x81）FEC元素类型的类型化通配符FEC元素。
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/rfc6667.
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/rfc6667.
Copyright Notice
版权公告
Copyright (c) 2012 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2012 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
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。从该文档中提取的代码组件必须
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.
包括信托法律条款第4.e节中所述的简化BSD许可证文本，且不提供简化BSD许可证中所述的担保。
This document may not be modified, and derivative works of it may not be created, except to format it for publication as an RFC or to translate it into languages other than English.
不得修改本文件，也不得创建其衍生作品，除非将其格式化为RFC出版或将其翻译为英语以外的其他语言。
Table of Contents
目录
1. Introduction ....................................................2
2. Typed Wildcard for PW FEC Elements ..............................3
3. Applicability Statement .........................................4
4. Operation .......................................................4
4.1. PW Consistency Check .......................................5
4.2. PW Graceful Shutdown .......................................5
4.3. Wildcard PW Status .........................................5
4.4. Typed Wildcard MAC Withdrawal in VPLS ......................6
5. Security Considerations .........................................6
6. Acknowledgments .................................................7
7. References ......................................................7
7.1. Normative References .......................................7
7.2. Informative References .....................................7
1. Introduction ....................................................2
2. Typed Wildcard for PW FEC Elements ..............................3
3. Applicability Statement .........................................4
4. Operation .......................................................4
4.1. PW Consistency Check .......................................5
4.2. PW Graceful Shutdown .......................................5
4.3. Wildcard PW Status .........................................5
4.4. Typed Wildcard MAC Withdrawal in VPLS ......................6
5. Security Considerations .........................................6
6. Acknowledgments .................................................7
7. References ......................................................7
7.1. Normative References .......................................7
7.2. Informative References .....................................7
An extension to the Label Distribution Protocol (LDP) [RFC5036] defines the general notion of a "Typed Wildcard Forwarding Equivalence Class (FEC) Element" [RFC5918]. This can be used when requesting, releasing, or withdrawing all label bindings for a given type of FEC Element is desired. However, a Typed Wildcard FEC Element must be individually defined for each type of FEC Element.
标签分发协议（LDP）[RFC5036]的扩展定义了“类型化通配符转发等价类（FEC）元素”[RFC5918]的一般概念。当需要为给定类型的FEC元素请求、释放或撤消所有标签绑定时，可以使用此选项。但是，必须为每种类型的FEC元素单独定义一个类型化通配符FEC元素。
[RFC4447] defines the "PWid FEC Element" and "Generalized PWid FEC Element", but does not specify the Typed Wildcard format for these elements. This document specifies the format of the Typed Wildcard FEC Element for the "PWid FEC Element" and "Generalized PWid FEC Element". The procedures for Typed Wildcard processing for PWid and Generalized PWid FEC Elements are the same as described in [RFC5918] for any Typed Wildcard FEC Element type.
[RFC4447]定义了“PWid FEC元素”和“广义PWid FEC元素”，但未指定这些元素的类型化通配符格式。本文档指定了“PWid FEC元素”和“广义PWid FEC元素”的类型化通配符FEC元素的格式。PWid和广义PWid FEC元素的类型化通配符处理过程与[RFC5918]中描述的任何类型化通配符FEC元素类型相同。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照RFC 2119[RFC2119]中所述进行解释。
The format of the Typed Wildcard FEC Element for PWid and Generalized PWid is specified as:
PWid和广义PWid的类型化通配符FEC元素的格式指定为：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Typed Wcard=0x5| Type=PW FEC | Len = 2 |R| PW type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . . . |
+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Typed Wcard=0x5| Type=PW FEC | Len = 2 |R| PW type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| . . . |
+-+-+-+-+-+-+-+-+
Figure 1: Format of Typed Wildcard FEC Element for PW FEC Element Types
图1:PW FEC元素类型的类型化通配符FEC元素的格式
Where:
哪里：
Typed Wcard (one octet): Typed Wildcard FEC Element type (0x05) as specified in [RFC5918].
类型化Wcard（一个八位字节）：按照[RFC5918]中的规定，类型化的通配符FEC元素类型（0x05）。
[FEC Element] Type (one octet): PW FEC Element type:
[FEC元件]类型（一个八位组）：PW FEC元件类型：
PWid: (type 0x80 [RFC4447]) Generalized PWid: (type 0x81 [RFC4447])
PWid:（类型0x80[RFC4447]）广义PWid:（类型0x81[RFC4447]）
Len [FEC Type Info] (one octet): Two. (There is additional FEC info to scope the Typed Wildcard.)
Len[FEC Type Info]（一个八位组）：两个。（有附加的FEC信息用于限定键入的通配符的范围。）
R bit (Reserved bit): MUST be set to ZERO on transmit and ignored on receipt.
R位（保留位）：传输时必须设置为零，接收时忽略。
PW type (15-bits): PW type as specified in [RFC4447]. This field is used to scope the wildcard FEC operation to limit all PWs of a given type. This MUST be set to "Wildcard" type (0x7FFF), as defined in [IANA-PWE3], when referring PWs of all types (see Section 4 for its usage).
PW类型（15位）：在[RFC4447]中规定的PW类型。此字段用于确定通配符FEC操作的范围，以限制给定类型的所有PW。在引用所有类型的PWs时，必须将其设置为[IANA-PWE3]中定义的“通配符”类型（0x7FFF）（其用法见第4节）。
[RFC4447] defines the "PW Grouping ID TLV" that can be used for wildcard withdrawal or status messages related to Generalized PWid FECs. When the Typed Wildcard FEC for Generalized PWid FEC element is in use, the "PW Grouping ID TLV" MUST NOT be present in the same message. If present, the receiving Label Switching Router (LSR) MUST ignore this TLV silently and process the rest of the message.
[RFC4447]定义了“PW分组ID TLV”，可用于通配符撤销或与通用PWid FEC相关的状态消息。当通用PWid FEC元素的类型化通配符FEC正在使用时，“PW分组ID TLV”不能出现在同一消息中。如果存在，接收标签交换路由器（LSR）必须以静默方式忽略此TLV并处理消息的其余部分。
The Typed Wildcard FEC Elements defined in this document for the PWid and Generalized PWid FEC Elements provide a finer degree of granularity when compared to the wildcard FEC mechanics defined in [RFC5036].
与[RFC5036]中定义的通配符FEC机制相比，本文档中为PWid和广义PWid FEC元素定义的类型化通配符FEC元素提供了更精细的粒度。
The PWid FEC Element as defined in [RFC4447] contains a Group ID field. This field is defined as an arbitrary 32-bit value that represents a group of PWs and is used to create groups in the PW space, including potentially a single group of all PWs for a given FEC Element type. This grouping enables an LSR to send "wildcard" label withdrawals and/or status notification messages corresponding to a PW group upon physical port failures. Similarly, [RFC4447] defines the "PW Grouping ID TLV" used in the same fashion for the Generalized PWid FEC Element.
[RFC4447]中定义的PWid FEC元素包含一个组ID字段。此字段定义为表示一组PW的任意32位值，用于在PW空间中创建组，可能包括给定FEC元素类型的所有PW的单个组。此分组使LSR能够在物理端口故障时发送与PW组对应的“通配符”标签撤回和/或状态通知消息。类似地，[RFC4447]定义了“PW分组ID TLV”，以相同的方式用于广义PWid FEC元素。
The PWid Typed Wildcard FEC Elements defined in this document help us achieve similar functionality as the "Group ID" field or "PW Grouping ID TLV" for label withdrawal and status notification messages. Additionally, the Typed Wildcard procedures [RFC5918] provide a more generalized and comprehensive solution by allowing:
本文档中定义的PWid类型通配符FEC元素有助于我们实现与标签撤销和状态通知消息的“组ID”字段或“PW分组ID TLV”类似的功能。此外，类型化通配符过程[RFC5918]提供了一个更通用、更全面的解决方案，允许：
1. Typed Wildcard Label Request messages
1. 类型化通配符标签请求消息
2. Label TLVs in label messages to further constrain the wildcard to all FECs of the specified FEC type [and its specific filter] that are also bound to the specified label.
2. 在标签消息中标记TLV，以进一步将通配符约束到指定FEC类型[及其特定筛选器]且也绑定到指定标签的所有FEC。
This document allows use of the Typed Wildcard PW FEC Element in any LDP message that specifies a FEC TLV as a mandatory or optional parameter of the message. In addition to LDP label messages, this also applies to notification messages (containing PW Status) and Address Withdraw (for MAC address withdrawal [RFC4762]) messages in the context of LDP PW signaling. When a Typed Wildcard PW FEC Element is used in an Address Withdraw message for Virtual Private LAN Service (VPLS) Media Access Control (MAC) address withdrawal, the MAC List TLV MUST contain an empty list.
本文档允许在任何LDP消息中使用类型通配符PW FEC元素，该LDP消息将FEC TLV指定为消息的强制或可选参数。除了LDP标签消息外，这也适用于LDP PW信令上下文中的通知消息（包含PW状态）和地址撤回（对于MAC地址撤回[RFC4762]）。当在虚拟专用LAN服务（VPLS）媒体访问控制（MAC）地址撤回的地址撤回消息中使用键入的通配符PW FEC元素时，MAC列表TLV必须包含空列表。
The use of Typed Wildcard FEC Elements for PW can be useful under several scenarios. This section describes some use cases to illustrate their application. The following use cases consider two LSR nodes, A and B, with an LDP session between them to exchange Layer 2 Virtual Private Network (L2VPN) PW bindings.
在几种情况下，为PW使用类型化通配符FEC元素非常有用。本节描述一些用例来说明它们的应用。下面的用例考虑两个LSR节点A和B，它们之间具有LDP会话来交换层2虚拟专用网络（L2VPN）PW绑定。
A user may request a control-plane consistency check at LSR A for the Generalized PWid FEC bindings that it learned from LSR B over the LDP session. To perform this consistency check, LSR A marks all its learned Generalized PWid FEC bindings from LSR B as stale, and then sends a Label Request message towards LSR B for the Typed Wildcard FEC Element for Generalized PWid FEC Element type with the PW type set to "Wildcard" (0x7FFF). Upon receipt of such a request, LSR B replays its database related to the Generalized PWid FEC Element using one or more Label Mapping messages. As a PW binding is received at LSR A, the associated binding state is marked as refreshed (not stale). When replay completes for the Generalized PWid FEC type, LSR B marks the end of its replay by sending an End-of-LIB notification [RFC5919] corresponding to the Generalized PWid FEC Element type. Upon receipt of this notification at LSR A, any remaining stale PW binding of the Generalized PWid FEC type learned from the peer LSR B is cleaned up and removed from the database. This completes the consistency check with LSR B at LSR A for Generalized PWid FEC type.
用户可以请求在LSR A处对其在LDP会话期间从LSR B获悉的广义PWid FEC绑定进行控制平面一致性检查。要执行此一致性检查，LSR A将其从LSR B学习到的所有广义PWid FEC绑定标记为过时，然后向LSR B发送一个标签请求消息，用于广义PWid FEC元素类型的类型化通配符FEC元素，PW类型设置为“通配符”（0x7FFF）。在接收到这样的请求后，LSR B使用一个或多个标签映射消息重放其与通用PWid FEC元素相关的数据库。当在LSR a接收到PW绑定时，关联的绑定状态被标记为刷新（非过时）。当通用PWid FEC类型的重播完成时，LSR B通过发送对应于通用PWid FEC元素类型的库结束通知[RFC5919]来标记其重播的结束。在LSR A收到此通知后，从对等LSR B学习到的通用PWid FEC类型的任何剩余陈旧PW绑定将被清除并从数据库中删除。这就完成了针对通用PWid FEC类型在LSR A处与LSR B的一致性检查。
It may be desirable to perform shutdown/removal of existing PW bindings advertised towards a peer in a graceful manner -- i.e., all advertised PW bindings are to be removed from a peer without session flap. For example, to request a graceful delete of the PWid FEC and Generalized PWid FEC bindings at LSR A learned from LSR B, LSR A would send a Label Withdraw message towards LSR B with Typed Wildcard FEC Elements pertaining to the PWid FEC Element (with PW type set to 0x7FFF) and Generalized PWid FEC Element (with PW type set to 0x7FFF). Upon receipt of such a message, LSR B would delete all PWid and Generalized PWid bindings learned from LSR A. Afterwards, LSR B would send Label Release messages corresponding to received Label Withdraw messages with the Typed FEC Element.
可能需要以优雅的方式关闭/删除向对等方播发的现有PW绑定——即，所有播发的PW绑定都将在没有会话切换的情况下从对等方删除。例如，为了请求在LSR a处优雅地删除从LSR B学习到的PWid FEC和通用PWid FEC绑定，LSR a将向LSR B发送一个标签撤销消息，其中包含与PWid FEC元素相关的类型通配符FEC元素（PW type设置为0x7FFF）和通用PWid FEC元素（PW type设置为0x7FFF）。收到此类消息后，LSR B将删除从LSR a学习到的所有PWid和通用PWid绑定。之后，LSR B将发送与接收到的带有类型化FEC元素的标签撤销消息相对应的标签释放消息。
The Typed Wildcard FEC Elements for PW FECs can be very useful to convey PW status amongst LSRs. The Provider Edge (PE) devices can send the "PW Status TLV" in an LDP Notification message to indicate PW status (i.e., a Pseudowire Status Code denoting, for example, a particular fault) to their remote peers [RFC4447]. In case of a global failure affecting all PWs, an LSR typically sends one PW Status LDP Notification message per PW. This per-PW-Status message has scalability implications in a large-scale network with a large number of PWs.
PW FEC的类型化通配符FEC元素对于在LSR之间传递PW状态非常有用。提供商边缘（PE）设备可以在LDP通知消息中发送“PW状态TLV”，以向其远程对等方指示PW状态（即，表示例如特定故障的伪线状态码）[RFC4447]。在全局故障影响所有PW的情况下，LSR通常为每个PW发送一条PW状态LDP通知消息。在具有大量PW的大规模网络中，此per PW Status消息具有可伸缩性影响。
Using Typed Wildcard FEC Element for a given type of PW FEC Element, the LSR will need to send only one PW Status Notification message with the Typed Wildcard PW FEC specified to notify about the common status applicable to all PWs as scoped by the PW Typed Wildcard FEC.
为给定类型的PW FEC元素使用类型化通配符FEC元素，LSR只需发送一条PW状态通知消息，其中指定类型化通配符PW FEC，以通知PW类型化通配符FEC范围内适用于所有PW的公共状态。
[RFC4762] defines a pseudowire-based solution to implement Virtual Private LAN Service (VPLS). Section 6.2 of RFC 4762 describes MAC Withdrawal procedures and extensions in a VPLS environment. These procedures use the LDP Address Withdraw message containing the FEC TLV (with the PW FEC element corresponding to the VPLS instance) and MAC List TLV (to specify addresses to be withdrawn). The procedures described in RFC 4762 also allow MAC address withdrawal wildcarding for a given VPLS instance.
[RFC4762]定义了一个基于伪线的解决方案，以实现虚拟专用LAN服务（VPLS）。RFC 4762第6.2节描述了VPLS环境中的MAC撤销程序和扩展。这些过程使用LDP地址撤销消息，该消息包含FEC TLV（PW FEC元素对应于VPLS实例）和MAC列表TLV（指定要撤销的地址）。RFC 4762中描述的过程还允许对给定VPLS实例进行MAC地址撤销通配符。
Using RFC 4762 procedures, a PE LSR can withdraw all MAC addresses for a given VPLS instance by sending an Address Withdraw message with a VPLS instance corresponding to the PW FEC element in a FEC TLV, and a MAC List TLV with an empty list of addresses. If there is more than one VPLS instance on a given PE LSR node, separate Address Withdraw messages need to be sent by the PE LSR if it wishes to withdraw MAC addresses for all or a subset of VPLS instances upon some global failure or configuration. Per-PW (VPLS instance) MAC Withdraw message may have some scalability implications in a large-scale network.
使用RFC 4762过程，PE LSR可以通过发送地址撤销消息（VPLS实例对应于FEC TLV中的PW FEC元素）和MAC列表TLV（地址列表为空），撤销给定VPLS实例的所有MAC地址。如果给定的PE LSR节点上有多个VPLS实例，如果PE LSR希望在某些全局故障或配置时提取所有或部分VPLS实例的MAC地址，则需要发送单独的地址提取消息。在大规模网络中，每PW（VPLS实例）MAC撤销消息可能具有一些可伸缩性影响。
As stated in Section 3, this document allows use of the Typed Wildcard PW FEC in Address Withdraw messages corresponding to VPLS MAC Withdrawal. The use of PW Typed Wildcard FEC enhances the scope of MAC withdrawal beyond just a single VPLS instance and allows a PE node to wildcard withdraw all MAC addresses for:
如第3节所述，本文件允许在与VPLS MAC撤回相对应的地址撤回消息中使用键入的通配符PW FEC。PW类型的通配符FEC的使用增强了MAC撤回的范围，而不仅仅是单个VPLS实例，并允许PE节点通配符撤回以下所有MAC地址：
o all VPLS instances; or o all VPLS instances corresponding to a given PW type.
o 所有VPLS实例；或o与给定PW类型对应的所有VPLS实例。
No new security considerations beyond those that apply to specifications [RFC5036], [RFC4447], [RFC4762], [RFC5918], and [RFC5920] apply to the use of the PW Typed Wildcard FEC Element types described in this document.
除了适用于规范[RFC5036]、[RFC4447]、[RFC4762]、[RFC5918]和[RFC5920]的安全注意事项外，没有其他新的安全注意事项适用于本文档中描述的PW类型通配符FEC元素类型的使用。
The authors would like to thank Eric Rosen, Reshad Rahman, Siva Sivabalan, and Zafar Ali for their review and valuable comments. We also acknowledge Daniel Cohn for suggesting use of the Typed Wildcard PW FEC for VPLS MAC withdrawal.
作者要感谢Eric Rosen、Reshad Rahman、Siva Sivabalan和Zafar Ali的评论和宝贵意见。我们还感谢Daniel Cohn建议使用类型通配符PW FEC退出VPLS MAC。
This document was prepared using 2-Word-v2.0 template.dot.
本文件使用2-Word-v2.0 template.dot编制。
[RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., "LDP Specification", RFC 5036, October 2007.
[RFC5036]Andersson，L.，Ed.，Minei，I.，Ed.，和B.Thomas，Ed.，“LDP规范”，RFC 5036，2007年10月。
[RFC5918] Asati, R., Minei, I., and B. Thomas, "Label Distribution Protocol (LDP) 'Typed Wildcard' Forward Equivalence Class (FEC)", RFC 5918, August 2010.
[RFC5918]Asati，R.，Minei，I.，和B.Thomas，“标签分发协议（LDP）“类型通配符”前向等价类（FEC）”，RFC 59182010年8月。
[RFC5919] Asati, R., Mohapatra, P., Chen, E., and B. Thomas, "Signaling LDP Label Advertisement Completion", RFC 5919, August 2010.
[RFC5919]Asati，R.，Mohapatra，P.，Chen，E.，和B.Thomas，“信号LDP标签广告完成”，RFC 5919，2010年8月。
[RFC4447] Martini, L., Ed., 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.，Ed.，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。
[RFC4762] Lasserre, M., Ed., and V. Kompella, Ed., "Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling", RFC 4762, January 2007.
[RFC4762]Lasserre，M.，Ed.，和V.Kompella，Ed.，“使用标签分发协议（LDP）信令的虚拟专用LAN服务（VPLS）”，RFC 4762，2007年1月。
[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。
[RFC5920] Fang, L., Ed., "Security Framework for MPLS and GMPLS Networks", RFC 5920, July 2010.
[RFC5920]方，L.，编辑，“MPLS和GMPLS网络的安全框架”，RFC 5920，2010年7月。
[IANA-PWE3] Internet Assigned Numbers Authority, "Pseudo Wires Name Spaces (PWE3)", http://www.iana.org/assignments/pwe3-parameters, May 2011.
[IANA-PWE3]互联网分配号码管理局，“伪电线名称空间（PWE3）”，http://www.iana.org/assignments/pwe3-parameters，2011年5月。
Authors' Addresses
作者地址
Kamran Raza Cisco Systems, Inc. 2000 Innovation Drive Ottawa ON K2K-3E8 Canada EMail: skraza@cisco.com
Kamran Raza Cisco Systems，Inc.2000加拿大渥太华创新大道K2K-3E8电子邮件：skraza@cisco.com
Sami Boutros Cisco Systems, Inc. 3750 Cisco Way San Jose, CA 95134 USA EMail: sboutros@cisco.com
Sami Boutros Cisco Systems，Inc.地址：美国加利福尼亚州圣何塞市思科大道3750号邮编：95134电子邮件：sboutros@cisco.com
Carlos Pignataro Cisco Systems, Inc. 7200 Kit Creek Road Research Triangle Park, NC 27709-4987 USA EMail: cpignata@cisco.com
Carlos Pignataro Cisco Systems，Inc.地址：美国北卡罗来纳州Kit Creek Road Research Triangle Park 7200邮编：27709-4987电子邮件：cpignata@cisco.com