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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
   working documents as Internet-Drafts.  The list of current Internet-
   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
   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



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   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.


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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