[Docs] [txt|pdf] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-ceccarelli-teas-gneralized-scsi) 00 01 02 03 04

TEAS Working Group                                         D. Ceccarelli
Internet-Draft                                                  Ericsson
Intended status: Standards Track                               L. Berger
Expires: March 3, 2018                           LabN Consulting, L.L.C.
                                                         August 30, 2017


   Generalized Interface Switching Capability Descriptor - Switching
                    Capability Specific Information
                     draft-ietf-teas-gmpls-scsi-04

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 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 associate
   protocol standards.

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 March 3, 2018.

Copyright Notice

   Copyright (c) 2017 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



Ceccarelli & Berger       Expires March 3, 2018                 [Page 1]


Internet-Draft              Generalized SCSI                 August 2017


   (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
   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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Generalized SCSI Formats  . . . . . . . . . . . . . . . . . .   3
   4.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   6
     8.3.  URIs  . . . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   The context for this document is Generalized MPLS, and the reader is
   expected to be familiar with the GMPLS architecture, associate
   terminology and protocol standards.  Notably, but not limited to,
   [RFC3945], [RFC4202], [RFC4203] and [RFC5307].

   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 [1] 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



Ceccarelli & Berger       Expires March 3, 2018                 [Page 2]


Internet-Draft              Generalized SCSI                 August 2017


   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", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   [RFC2119].

   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].

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].  Please also refer to
   [RFC3630] for the treatment of malformed Link TLVs.

   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.

   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




Ceccarelli & Berger       Expires March 3, 2018                 [Page 3]


Internet-Draft              Generalized SCSI                 August 2017


      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 definition
      indicated by value of the Type field.  This field can be omitted
      for certain types.

4.  Procedures

   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.

   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
   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 the the "Generalized Multi-Protocol Label
   Switching (GMPLS) Signaling Parameters" registry.




Ceccarelli & Berger       Expires March 3, 2018                 [Page 4]


Internet-Draft              Generalized SCSI                 August 2017


   The definition of the new registry is as follows:


       Value       SCSI-TLV                Switching Type   Reference
       ---------   ----------------------- --------------   ---------
       0           Reserved                                 [This ID]
       1-65535     Unassigned              (value list)     [This ID]


   New allocation requests to this registry must indicate the value or
   values to be used in the Switching Type column.

   The registry should be established with registration policies of
   "Specification Required", see [RFC5226].

   REMOVE THIS AFTER PUBLICATION: The designated expert will be
   appointed by the Routing AD.  It is suggested to appoint any current
   TEAS WG chair.

7.  Acknowledgments

   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.

8.  References

8.1.  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, <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>.

   [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>.

   [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>.



Ceccarelli & Berger       Expires March 3, 2018                 [Page 5]


Internet-Draft              Generalized SCSI                 August 2017


   [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>.

8.2.  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-10 (work in progress), August 2017.

   [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>.

   [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>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", RFC 5226,
              DOI 10.17487/RFC5226, May 2008, <https://www.rfc-
              editor.org/info/rfc5226>.

   [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>.

   [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>.

   [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>.

8.3.  URIs

   [1] http://www.iana.org/assignments/gmpls-sig-parameters/gmpls-sig-
       parameters.xml#gmpls-sig-parameters-3




Ceccarelli & Berger       Expires March 3, 2018                 [Page 6]


Internet-Draft              Generalized SCSI                 August 2017


Authors' Addresses

   Daniele Ceccarelli
   Ericsson
   Torshamnsgatan 21
   Kista - Stockholm
   Sweden

   Email: daniele.ceccarelli@ericsson.com


   Lou Berger
   LabN Consulting, L.L.C.

   Email: lberger@labn.net




































Ceccarelli & Berger       Expires March 3, 2018                 [Page 7]


Html markup produced by rfcmarkup 1.124, available from https://tools.ietf.org/tools/rfcmarkup/