Network Working Group H. Ould-Brahim
Request for Comments: 5543 Nortel Networks
Category: Standards Track D. Fedyk
Alcatel-Lucent
Y. Rekhter
Juniper Networks
May 2009
Network Working Group H. Ould-Brahim
Request for Comments: 5543 Nortel Networks
Category: Standards Track D. Fedyk
Alcatel-Lucent
Y. Rekhter
Juniper Networks
May 2009
BGP Traffic Engineering Attribute
流量工程属性
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2009 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 in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document.
本文件受BCP 78和IETF信托在本文件出版之日生效的与IETF文件有关的法律规定的约束(http://trustee.ietf.org/license-info). 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。
Abstract
摘要
This document defines a new BGP attribute, the Traffic Engineering attribute, that enables BGP to carry Traffic Engineering information.
本文档定义了一个新的BGP属性，即流量工程属性，该属性使BGP能够承载流量工程信息。
The scope and applicability of this attribute currently excludes its use for non-VPN reachability information.
此属性的范围和适用性目前不包括对非VPN可达性信息的使用。
In certain cases (e.g., Layer-1 VPNs (L1VPNs) [RFC5195]), it may be useful to augment the VPN reachability information carried in BGP with Traffic Engineering information.
在某些情况下（例如，第1层VPN（L1VPN）[RFC5195]），可以使用流量工程信息来增强BGP中携带的VPN可达性信息。
This document defines a new BGP attribute, the Traffic Engineering attribute, that enables BGP [RFC4271] to carry Traffic Engineering information.
本文档定义了一个新的BGP属性，即流量工程属性，该属性使BGP[RFC4271]能够承载流量工程信息。
Section 4 of [RFC5195] describes one possible usage of this attribute.
[RFC5195]的第4节描述了此属性的一种可能用法。
The scope and applicability of this attribute currently excludes its use for non-VPN reachability information.
此属性的范围和适用性目前不包括对非VPN可达性信息的使用。
Procedures for modifying the Traffic Engineering attribute, when re-advertising a route that carries such an attribute, are outside the scope of this document.
当重新发布带有交通工程属性的路线时，修改交通工程属性的步骤不在本文档的范围内。
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 Traffic Engineering attribute is an optional, non-transitive BGP attribute.
流量工程属性是可选的、不可传递的BGP属性。
The information carried in this attribute is identical to what is carried in the Interface Switching Capability Descriptor, as specified in [RFC4203] and [RFC5307].
此属性中包含的信息与[RFC4203]和[RFC5307]中指定的接口交换能力描述符中包含的信息相同。
The attribute contains one or more of the following:
该属性包含以下一项或多项：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Cap | Encoding | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Capability specific information |
| (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Cap | Encoding | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 2 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 3 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 5 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 6 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Max LSP Bandwidth at priority 7 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Switching Capability specific information |
| (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Switching Capability (Switching Cap) field contains one of the values specified in Section 3.1.1 of [RFC3471].
切换能力（切换上限）字段包含[RFC3471]第3.1.1节中规定的值之一。
The Encoding field contains one of the values specified in Section 3.1.1 of [RFC3471].
编码字段包含[RFC3471]第3.1.1节中规定的值之一。
The Reserved field SHOULD be set to 0 on transmit and MUST be ignored on receive.
传输时保留字段应设置为0，接收时必须忽略。
Maximum LSP (Label Switched Path) Bandwidth is encoded as a list of eight 4-octet fields in the IEEE floating point format [IEEE], with priority 0 first and priority 7 last. The units are bytes (not bits!) per second.
最大LSP（标签交换路径）带宽编码为IEEE浮点格式[IEEE]中八个4-octet字段的列表，优先级为0，优先级为7。单位为每秒字节（不是位！）。
The content of the Switching Capability specific information field depends on the value of the Switching Capability field.
交换能力特定信息字段的内容取决于交换能力字段的值。
When the Switching Capability field is PSC-1, PSC-2, PSC-3, or PSC-4, the Switching Capability specific information field includes Minimum LSP Bandwidth and Interface MTU.
当交换能力字段为PSC-1、PSC-2、PSC-3或PSC-4时，交换能力特定信息字段包括最小LSP带宽和接口MTU。
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Minimum LSP Bandwidth is encoded in a 4-octet field in the IEEE floating point format. The units are bytes (not bits!) per second. Interface MTU is encoded as a 2-octet integer.
最小LSP带宽以IEEE浮点格式编码在4个八位组字段中。单位为每秒字节（不是位！）。接口MTU编码为2个八位整数。
When the Switching Capability field is Layer-2 Switch Capable (L2SC), there is no Switching Capability specific information field present.
当交换能力字段为第2层交换能力（L2SC）时，不存在特定于交换能力的信息字段。
When the Switching Capability field is Time-Division-Multiplex (TDM) capable, the Switching Capability specific information field includes Minimum LSP Bandwidth and an indication of whether the interface supports Standard or Arbitrary SONET/SDH (Synchronous Optical Network / Synchronous Digital Hierarchy).
当交换能力字段具有时分复用（TDM）能力时，交换能力特定信息字段包括最小LSP带宽和接口是否支持标准或任意SONET/SDH（同步光网络/同步数字体系）的指示。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Indication |
+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Minimum LSP Bandwidth |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Indication |
+-+-+-+-+-+-+-+-+
Minimum LSP Bandwidth is encoded in a 4-octet field in the IEEE floating point format. The units are bytes (not bits!) per second. The indication of whether the interface supports Standard or Arbitrary SONET/SDH is encoded as 1 octet. The value of this octet is 0 if the interface supports Standard SONET/SDH, and 1 if the interface supports Arbitrary SONET/SDH.
最小LSP带宽以IEEE浮点格式编码在4个八位组字段中。单位为每秒字节（不是位！）。接口是否支持标准或任意SONET/SDH的指示编码为1个八位字节。如果接口支持标准SONET/SDH，则此八位字节的值为0；如果接口支持任意SONET/SDH，则此八位字节的值为1。
When the Switching Capability field is Lambda Switch Capable (LSC), there is no Switching Capability specific information field present.
当切换能力字段为Lambda Switch Capable（LSC）时，不存在特定于切换能力的信息字段。
Routes that carry the Traffic Engineering attribute have additional semantics that could affect traffic-forwarding behavior. Therefore, such routes SHALL NOT be aggregated unless they share identical Traffic Engineering attributes.
带有流量工程属性的路由具有可能影响流量转发行为的附加语义。因此，除非这些路线具有相同的交通工程属性，否则不得对其进行聚合。
Constructing the Traffic Engineering attribute when aggregating routes with identical Traffic Engineering attributes follows the procedure of [RFC4201].
聚合具有相同流量工程属性的路由时，按照[RFC4201]的过程构造流量工程属性。
The use of the Traffic Engineering attribute does not increase the number of routes, but may increase the number of BGP Update messages required to distribute the routes, depending on whether or not these routes share the same BGP Traffic Engineering attribute (see below).
流量工程属性的使用不会增加路由数，但可能会增加分发路由所需的BGP更新消息数，具体取决于这些路由是否共享相同的BGP流量工程属性（见下文）。
When the routes differ other than in the Traffic Engineering attribute (e.g., differ in the set of Route Targets and/or NEXT_HOP), use of the Traffic Engineering attribute has no impact on the number of BGP Update messages required to carry the routes. There is also no impact when routes share all other attribute information and have an aggregated or identical Traffic Engineering attribute. When routes share all other attribute information and have different Traffic Engineering attributes, routes must be distributed in per-route BGP Update messages, rather than in a single message.
当路由不同于流量工程属性（例如，路由目标集和/或下一跳不同）时，使用流量工程属性不会影响承载路由所需的BGP更新消息的数量。当路由共享所有其他属性信息且具有聚合或相同的流量工程属性时，也不会产生影响。当路由共享所有其他属性信息并具有不同的流量工程属性时，路由必须分布在每个路由BGP更新消息中，而不是单个消息中。
This document defines a new BGP attribute, Traffic Engineering. This attribute is optional and non-transitive.
本文档定义了一个新的BGP属性，即流量工程。此属性是可选的且不可传递。
This extension to BGP does not change the underlying security issues currently inherent in BGP. BGP security considerations are discussed in RFC 4271.
BGP的这一扩展并没有改变BGP目前固有的基本安全问题。RFC 4271中讨论了BGP安全注意事项。
The authors would like to thank John Scudder and Jeffrey Haas for their review and comments.
作者要感谢John Scudder和Jeffrey Haas的评论和评论。
[IEEE] IEEE, "IEEE Standard for Binary Floating-Point Arithmetic", Standard 754-1985, 1985 (ISBN 1-5593-7653-8).
[IEEE]IEEE，“二进制浮点运算的IEEE标准”，标准754-19851985（ISBN 1-5593-7653-8）。
[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。
[RFC3471] Berger, L., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Functional Description", RFC 3471, January 2003.
[RFC3471]Berger，L.，Ed.“通用多协议标签交换（GMPLS）信令功能描述”，RFC 3471，2003年1月。
[RFC4201] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in MPLS Traffic Engineering (TE)", RFC 4201, October 2005.
[RFC4201]Kompella，K.，Rekhter，Y.，和L.Berger，“MPLS流量工程（TE）中的链路捆绑”，RFC 42012005年10月。
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006.
[RFC4271]Rekhter，Y.，Ed.，Li，T.，Ed.，和S.Hares，Ed.，“边境网关协议4（BGP-4）”，RFC 42712006年1月。
[RFC4203] Kompella, K., Ed., and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, October 2005.
[RFC4203]Kompella，K.，Ed.，和Y.Rekhter，Ed.，“支持通用多协议标签交换（GMPLS）的OSPF扩展”，RFC 4203，2005年10月。
[RFC5195] Ould-Brahim, H., Fedyk, D., and Y. Rekhter, "BGP-Based Auto-Discovery for Layer-1 VPNs", RFC 5195, June 2008.
[RFC5195]Ould Brahim，H.，Fedyk，D.，和Y.Rekhter，“基于BGP的第一层VPN自动发现”，RFC 51952008年6月。
[RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 5307, October 2008.
[RFC5307]Kompella，K.，Ed.，和Y.Rekhter，Ed.，“支持通用多协议标签交换（GMPLS）的IS-IS扩展”，RFC 5307，2008年10月。
Authors' Addresses
作者地址
Hamid Ould-Brahim Nortel Networks EMail: hbrahim@nortel.com
哈米德·乌尔德·布拉希姆北电网络电子邮件：hbrahim@nortel.com
Don Fedyk Alcatel-Lucent EMail: donald.fedyk@alcatel-lucent.com Phone: 978-467-5645
唐·费迪克·阿尔卡特·朗讯电子邮件：唐纳德。fedyk@alcatel-朗讯网电话：978-467-5645
Yakov Rekhter Juniper Networks, Inc. EMail: yakov@juniper.net
Yakov Rekhter Juniper Networks，Inc.电子邮件：yakov@juniper.net