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Versions: 00 draft-ietf-teas-gmpls-scsi
TEAS Working Group D. Ceccarelli
Internet-Draft Ericsson
Intended status: Standards Track L. Berger
Expires: April 30, 2017 LabN Consulting, L.L.C.
October 27, 2016
Generalized Routing Interface Switching Capability Descriptor Switching
Capability Specific Information
draft-ceccarelli-teas-gneralized-scsi-00
Abstract
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 an existing technology specific formats and is defined for use
in conjunction with new GMPLS Switching Capability types.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
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Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 30, 2017.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
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publication of this document. Please review these documents
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to this document. Code Components extracted from this document must
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described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Generalized SCSI Formats . . . . . . . . . . . . . . . . . . . 3
4. Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
7.1. Normative References . . . . . . . . . . . . . . . . . . . 6
7.2. Informative References . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7
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1. Introduction
The Interface Switching Capability Descriptor (ISCD) [RFC4202] allows
routing protocols such as OSPF and ISIS to carry technology specific
information in the the Switching Capability-specific information
(SCSI) 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 (SC) type field. Existing
Switching Capabilities are managed by IANA in the Switching Types
registry and the related "IANA-GMPLS-TC-MIB" definitions.
[RFC7138] introduced a "sub-TLV" structure to its technology specific
SCSI field. The Sub-Type-Length-Value (TLV) based approach allows
for greater flexibility in the structure, ordering, and ability to
support extensions of the SC (technology) specific format. This Sub-
TLV approach is also used in [RFC7688].
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.,
[I-D.ietf-ccamp-ospf-availability-extension]). This document also
establishes a registry for SCSI-TLV definitions that may be shared
across multiple technologies.
2. Terminology
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 [RFC2119].
3. Generalized SCSI Formats
The Generalized SCSI is composed of zero or more variable length
type-length-value fields which are each called a SCSI-TLV. There are
no specific size restrictions on these SCSI-TLV. Size and other
formatting restrictions may be imposed by the routing protocol ISCD
field, refer to [RFC4203] and [RFC5307].
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The SCSI-TLV format is:
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
Type (2 octets):
This field indicates the type and structure of the information
contained in the Value field. Note that the value range of this
field has been split in two. The lower range is used to indicated
technology specific formats, while the higher range is reserved
for formats that can be used with more than one technology. See
Section 6
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.
Value (variable):
A variable length field, formatted according to the value of the
Type field. This field can be omitted for certain types.
4. Procedures
The Generalized SCSI is used with ISCDs (defined in [RFC4203] and
[RFC5307]) of technologies whose Switching Capability definition
reference 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.
The Generalized SCSI MAY contain a sequence of zero or more SCSI-
TLVs. Sub-TLV parsing (format) errors, such as an underrun or
overrun, 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
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on the definition on the type.
5. Security Considerations
This document does not introduce any security issue beyond those
discussed in [RFC4203] and [RFC5307]. As discussed there, the
information carried in ISCDs are not used for SPF computation or
normal routing and the extensions here defined do not have direct
effect on IP routing. Tampering with GMPLS TE LSAs may have an
effect on the underlying transport network. Mechanisms such as
[RFC2154] and [RFC5304] to protect the transmission of this
information are suggested.
6. IANA Considerations
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.
IANA is requested to create and maintain a new registry, the
"Generalized SCSI (Switching Capability Specific Information) TLVs
Types" registry under either the the "Generalized Multi-Protocol
Label Switching (GMPLS) Signaling Parameters" registry or a new
"Generalized Multi-Protocol Label Switching (GMPLS) Routing
Parameters" registry.
The definition of the new registry is as follows:
Value SCSI-TLV SwitchCap Reference
--------- -------------------------- --------- ---------
0 Reserved [This ID]
1-32768 Unassigned, for use by [per value]
specific technology [This ID]
32768-65535 Unassigned, for others (Any, or
value list) [This ID]
New allocation requests to this registry SHALL indicate the value or
values to be used in the SwitchCap column.
The registry should be established with registration policies of
"Standards Action" for Standards Track documents, and "Specification
Required" for other documents, see [RFC5226]. The designated expert
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is any current TEAS WG chair.
7. References
7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/
RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[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,
<http://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,
<http://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,
<http://www.rfc-editor.org/info/rfc5307>.
7.2. Informative References
[I-D.ietf-ccamp-ospf-availability-extension]
Long, H., Ye, M., Mirsky, G., D'Alessandro, A., and H.
Shah, "OSPF-TE Link Availability Extension for Links with
Variable Discrete Bandwidth",
draft-ietf-ccamp-ospf-availability-extension-08 (work in
progress), October 2016.
[RFC2154] Murphy, S., Badger, M., and B. Wellington, "OSPF with
Digital Signatures", RFC 2154, DOI 10.17487/RFC2154,
June 1997, <http://www.rfc-editor.org/info/rfc2154>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>.
[RFC5304] Li, T. and R. Atkinson, "IS-IS Cryptographic
Authentication", RFC 5304, DOI 10.17487/RFC5304,
October 2008, <http://www.rfc-editor.org/info/rfc5304>.
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[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,
<http://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,
<http://www.rfc-editor.org/info/rfc7688>.
Authors' Addresses
Daniele Ceccarelli
Ericsson
Torshamnsgatan 21
Kista - Stockholm
Sweden
Email: daniele.ceccarelli@ericsson.com
Lou Berger
LabN Consulting, L.L.C.
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