Internet Engineering Task Force (IETF) D. Ceccarelli
Request for Comments: 8258 Ericsson
Category: Standards Track L. Berger
ISSN: 2070-1721 LabN Consulting, L.L.C.
October 2017
Internet Engineering Task Force (IETF) D. Ceccarelli
Request for Comments: 8258 Ericsson
Category: Standards Track L. Berger
ISSN: 2070-1721 LabN Consulting, L.L.C.
October 2017
Generalized SCSI: A Generic Structure for Interface Switching Capability Descriptor (ISCD) Switching Capability Specific Information (SCSI)
通用SCSI：接口交换能力描述符（ISCD）交换能力特定信息（SCSI）的通用结构
Abstract
摘要
This document defines a generic information structure for information carried in routing protocol Interface Switching Capability Descriptor (ISCD) Switching Capability Specific Information (SCSI) fields. This "Generalized SCSI" can be used with routing protocols that define GMPLS ISCDs and any specific technology. This document does not modify any existing technology-specific formats and is defined for use in conjunction with new GMPLS Switching Capability types. The context for this document is Generalized MPLS, and the reader is expected to be familiar with the GMPLS architecture and associated protocol standards.
本文档为路由协议接口交换能力描述符（ISCD）交换能力特定信息（SCSI）字段中携带的信息定义了通用信息结构。这种“通用SCSI”可用于定义GMPLS ISCD和任何特定技术的路由协议。本文件不修改任何现有的技术特定格式，定义为与新的GMPLS交换能力类型一起使用。本文档的上下文为通用MPLS，读者应熟悉GMPLS体系结构和相关协议标准。
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/rfc8258.
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/rfc8258.
Copyright Notice
版权公告
Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2017 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 . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Generalized SCSI Formats . . . . . . . . . . . . . . . . . . 3
4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Generalized SCSI Formats . . . . . . . . . . . . . . . . . . 3
4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 6
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
The context for this document is Generalized MPLS, and the reader is expected to be familiar with the GMPLS architecture, associated terminology, and protocol standards: notably, but not limited to, [RFC3945], [RFC4202], [RFC4203] and [RFC5307].
本文档的上下文为通用MPLS，读者应熟悉GMPLS体系结构、相关术语和协议标准：尤其是但不限于[RFC3945]、[RFC4202]、[RFC4203]和[RFC5307]。
The Interface Switching Capability Descriptor (ISCD) [RFC4202] allows routing protocols such as OSPF and ISIS to carry technology-specific information in the Switching Capability-specific information field, see [RFC4203] and [RFC5307]. The format of an SCSI field is dictated by the specific technology being represented as indicated by the ISCD Switching Capability field. Existing Switching Capabilities are managed by IANA in the "Switching Types" registry <http://www.iana.org/assignments/gmpls-sig-parameters> and the related "IANA-GMPLS-TC-MIB" definitions.
接口交换能力描述符（ISCD）[RFC4202]允许OSPF和ISIS等路由协议在交换能力特定信息字段中携带特定于技术的信息，请参见[RFC4203]和[RFC5307]。SCSI字段的格式由特定技术决定，如ISCD交换能力字段所示。现有的交换功能由IANA在“交换类型”注册表中管理<http://www.iana.org/assignments/gmpls-sig-parameters>以及相关的“IANA-GMPLS-TC-MIB”定义。
[RFC7138] introduced a "sub-TLV" structure to its technology-specific SCSI field. The sub-TLV-based approach allows for greater flexibility in the structure, ordering, and ability to support extensions of the SC-specific format. This Sub-TLV approach is also used in [RFC7688].
[RFC7138]在其特定于技术的SCSI字段中引入了“子TLV”结构。基于子TLV的方法允许在结构、顺序和支持SC特定格式扩展的能力方面具有更大的灵活性。[RFC7688]中也使用了这种子TLV方法。
This document generalizes this approach and defines a new generalized SCSI field format for use by future specific technologies and Switching Capability types. The generalized SCSI carries SCSI-TLVs that may be defined within the scope of a specific technology or shared across multiple technologies (e.g., [AVAIL-EXT]). This document also establishes a registry for SCSI-TLV definitions that may be shared across multiple technologies.
本文档概括了这种方法，并定义了一种新的通用SCSI字段格式，供未来特定的技术和交换能力类型使用。通用SCSI携带SCSI TLV，这些TLV可以在特定技术范围内定义，也可以跨多种技术（例如，[AVAIL-EXT]）共享。本文档还为可跨多种技术共享的SCSI-TLV定义建立了注册表。
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。
The reader is expected to be familiar with GMPLS terminology (e.g., as found in [RFC3945]) as well as the terminology used in [RFC4202], [RFC4203], and [RFC5307].
读者应熟悉GMPLS术语（如[RFC3945]中的术语）以及[RFC4202]、[RFC4203]和[RFC5307]中使用的术语。
The Generalized SCSI is composed of zero or more variable-length TLV fields each of which is called an "SCSI-TLV". There are no specific size restrictions on these SCSI-TLVs. Size and other formatting restrictions may be imposed by the routing protocol ISCD field (refer to [RFC4203] and [RFC5307]). Please refer to [RFC3630] for the treatment of malformed Link TLVs.
通用SCSI由零个或多个可变长度TLV字段组成，每个字段称为“SCSI-TLV”。这些SCSI TLV没有具体的大小限制。路由协议ISCD字段可能会施加大小和其他格式限制（请参阅[RFC4203]和[RFC5307]）。请参考[RFC3630]了解错误链路TLV的处理方法。
The SCSI-TLV format is:
SCSI-TLV格式为：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Value ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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 | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
... Value ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: TLV Format
图1:TLV格式
Type (2 octets): This field indicates the type and structure of the information contained in the Value field.
类型（2个八位字节）：此字段指示值字段中包含的信息的类型和结构。
Length (2 octets): This field MUST be set to the size, in octets (bytes), of the Value field. The value of the field MUST be zero or divisible by 4. Note that this implies that the Value field can be omitted or contain padding.
长度（2个八位字节）：此字段必须设置为值字段的大小，以八位字节（字节）为单位。字段的值必须为零或可被4整除。请注意，这意味着值字段可以省略或包含填充。
Value (variable): A variable-length field, formatted according to the definition indicated by value of the Type field. This field can be omitted for certain types.
值（变量）：一个可变长度字段，根据类型字段的值指示的定义格式化。对于某些类型，可以省略此字段。
The ISCD can include a Generalized SCSI when advertising technologies whose Switching Capability definition references this document. The corollary of this is that the Generalized SCSI MUST NOT be used for ISCDs of technologies whose Switching Capability definition do not reference this document.
ISCD可以包括一个通用的SCSI，用于宣传其交换能力定义引用本文档的技术。由此产生的推论是，通用SCSI不得用于交换能力定义未参考本文档的ISCD技术。
The Generalized SCSI MAY contain a sequence of zero or more SCSI-TLVs. Sub-TLV parsing (format) errors MUST be treated as a malformed ISCD. SCSI-TLVs MUST be processed in the order received and, if re-originated, ordering MUST be preserved. Unknown SCSI-TLVs MUST be ignored and transparently processed, i.e., re-originated when appropriate. Processing related to multiple SCSI-TLVs of the same type may be further refined based on the definition on the type.
通用SCSI可能包含零个或多个SCSI TLV序列。必须将子TLV解析（格式）错误视为格式错误的ISCD。SCSI TLV必须按照收到的顺序进行处理，如果重新发起，则必须保留顺序。必须忽略未知的SCSI TLV并进行透明处理，即在适当时重新启动。与同一类型的多个SCSI TLV相关的处理可以根据该类型的定义进一步细化。
This document does not introduce any security issue beyond those discussed in [RFC4203] and [RFC5307]. As discussed there, the information carried in ISCDs is not used for Shortest Path First (SPF) computation or normal routing, and the extensions here defined do not have a direct effect on IP routing. Tampering with GMPLS Traffic Engineering (TE) Link State Advertisements (LSAs) may have an effect on the underlying transport network. Mechanisms such as those described in [RFC2154] and [RFC5304] to protect the transmission of this information are suggested.
除[RFC4203]和[RFC5307]中讨论的安全问题外，本文件不引入任何安全问题。如上所述，ISCDs中携带的信息不用于最短路径优先（SPF）计算或正常路由，此处定义的扩展对IP路由没有直接影响。篡改GMPLS流量工程（TE）链路状态广告（LSA）可能会对底层传输网络产生影响。建议采用[RFC2154]和[RFC5304]中所述的机制来保护该信息的传输。
This document defines a new SCSI-TLV that is carried in the SCSI field of the ISCDs defined in [RFC4203] and [RFC5307]. The SCSI-TLV includes a 16-bit type identifier (the Type field). The same Type field values are applicable to the new SCSI-TLV.
本文档定义了在[RFC4203]和[RFC5307]中定义的ISCD的SCSI字段中携带的新SCSI-TLV。SCSI-TLV包含一个16位类型标识符（类型字段）。相同类型的字段值适用于新的SCSI-TLV。
IANA has created and will maintain a new registry, the "Generalized SCSI (Switching Capability Specific Information) TLV Types" registry under the "Generalized Multi-Protocol Label Switching (GMPLS) Signaling Parameters" registry.
IANA已经创建并将维护一个新的注册表，即“通用多协议标签交换（GMPLS）信令参数”注册表下的“通用SCSI（交换能力特定信息）TLV类型”注册表。
The initial contents of this registry are as follows:
本登记册的初始内容如下：
Value SCSI-TLV Switching Type Reference
--------- ----------------------- -------------- ---------
0 Reserved [RFC8258]
1-65535 Unassigned (value list)
Value SCSI-TLV Switching Type Reference
--------- ----------------------- -------------- ---------
0 Reserved [RFC8258]
1-65535 Unassigned (value list)
New allocation requests to this registry must indicate the value or values to be used in the Switching Type column.
对此注册表的新分配请求必须指明要在“切换类型”列中使用的一个或多个值。
The registry should be established with registration policies of "Specification Required", see [RFC8126].
注册中心的注册策略应为“要求规范”，请参见[RFC8126]。
[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>.
[RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, DOI 10.17487/RFC3630, September 2003, <https://www.rfc-editor.org/info/rfc3630>.
[RFC3630]Katz，D.，Kompella，K.，和D.Yeung，“OSPF版本2的交通工程（TE）扩展”，RFC 3630，DOI 10.17487/RFC3630，2003年9月<https://www.rfc-editor.org/info/rfc3630>.
[RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, <https://www.rfc-editor.org/info/rfc4202>.
[RFC4202]Kompella，K.，Ed.和Y.Rekhter，Ed.，“支持通用多协议标签交换（GMPLS）的路由扩展”，RFC 4202，DOI 10.17487/RFC4202，2005年10月<https://www.rfc-editor.org/info/rfc4202>.
[RFC4203] Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005, <https://www.rfc-editor.org/info/rfc4203>.
[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，DOI 10.17487/RFC4203，2005年10月<https://www.rfc-editor.org/info/rfc4203>.
[RFC5307] Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008, <https://www.rfc-editor.org/info/rfc5307>.
[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，DOI 10.17487/RFC5307，2008年10月<https://www.rfc-editor.org/info/rfc5307>.
[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>.
[AVAIL-EXT] Long, H., Ye, M., Mirsky, G., D'Alessandro, A., and H. Shah, "OSPF-TE Link Availability Extension for Links with Variable Discrete Bandwidth", Work in Progress, draft-ietf-ccamp-ospf-availability-extension-10, August 2017.
[AVAIL-EXT]Long，H.，Ye，M.，Mirsky，G.，D'Alessandro，A.，和H.Shah，“可变离散带宽链路的OSPF-TE链路可用性扩展”，正在进行的工作，草稿-ietf-ccamp-OSPF-Availability-Extension-10，2017年8月。
[RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with Digital Signatures", RFC 2154, DOI 10.17487/RFC2154, June 1997, <https://www.rfc-editor.org/info/rfc2154>.
[RFC2154]Murphy，S.，Badger，M.，和B.Wellington，“具有数字签名的OSPF”，RFC 2154，DOI 10.17487/RFC2154，1997年6月<https://www.rfc-editor.org/info/rfc2154>.
[RFC3945] Mannie, E., Ed., "Generalized Multi-Protocol Label Switching (GMPLS) Architecture", RFC 3945, DOI 10.17487/RFC3945, October 2004, <https://www.rfc-editor.org/info/rfc3945>.
[RFC3945]Mannie，E.，Ed.“通用多协议标签交换（GMPLS）体系结构”，RFC 3945，DOI 10.17487/RFC3945，2004年10月<https://www.rfc-editor.org/info/rfc3945>.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic Authentication", RFC 5304, DOI 10.17487/RFC5304, October 2008, <https://www.rfc-editor.org/info/rfc5304>.
[RFC5304]Li，T.和R.Atkinson，“IS-IS加密认证”，RFC 5304，DOI 10.17487/RFC5304，2008年10月<https://www.rfc-editor.org/info/rfc5304>.
[RFC7138] Ceccarelli, D., Ed., Zhang, F., Belotti, S., Rao, R., and J. Drake, "Traffic Engineering Extensions to OSPF for GMPLS Control of Evolving G.709 Optical Transport Networks", RFC 7138, DOI 10.17487/RFC7138, March 2014, <https://www.rfc-editor.org/info/rfc7138>.
[RFC7138]Ceccarelli，D.，Ed.，Zhang，F.，Belotti，S.，Rao，R.，和J.Drake，“用于GMPLS控制不断发展的G.709光传输网络的OSPF流量工程扩展”，RFC 7138，DOI 10.17487/RFC7138，2014年3月<https://www.rfc-editor.org/info/rfc7138>.
[RFC7688] Lee, Y., Ed. and G. Bernstein, Ed., "GMPLS OSPF Enhancement for Signal and Network Element Compatibility for Wavelength Switched Optical Networks", RFC 7688, DOI 10.17487/RFC7688, November 2015, <https://www.rfc-editor.org/info/rfc7688>.
[RFC7688]Lee，Y.，Ed.和G.Bernstein，Ed.，“波长交换光网络信号和网元兼容性的GMPLS OSPF增强”，RFC 7688，DOI 10.17487/RFC7688，2015年11月<https://www.rfc-editor.org/info/rfc7688>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, <https://www.rfc-editor.org/info/rfc8126>.
[RFC8126]Cotton，M.，Leiba，B.，和T.Narten，“在RFC中编写IANA考虑事项部分的指南”，BCP 26，RFC 8126，DOI 10.17487/RFC8126，2017年6月<https://www.rfc-editor.org/info/rfc8126>.
Acknowledgments
致谢
The authors would like to thank Adrian Farrel and Julien Meuric for the careful review and suggestions. Thomas Heide Clausen provided useful comments as part of the Routing Directorate review.
作者要感谢Adrian Farrel和Julien Meuria的仔细审查和建议。托马斯·海德·克劳森（Thomas Heide Clausen）提供了有用的意见，作为路由理事会审查的一部分。
Authors' Addresses
作者地址
Daniele Ceccarelli Ericsson Torshamnsgatan 21 Kista - Stockholm Sweden
Daniele Ceccarelli Ericsson Torshamnsgatan 21基斯塔-瑞典斯德哥尔摩
Email: daniele.ceccarelli@ericsson.com
Email: daniele.ceccarelli@ericsson.com
Lou Berger LabN Consulting, L.L.C.
Lou Berger LabN咨询公司，L.L.C。
Email: lberger@labn.net
Email: lberger@labn.net