Revised Definition of the GMPLS Switching Capability and Type Fields
RFC 7074

Internet Engineering Task Force (IETF)                         L. Berger
Request for Comments: 7074                                          LabN
Updates: 3471, 4202, 4203, 5307                                J. Meuric
Category: Standards Track                                         Orange
ISSN: 2070-1721                                            November 2013

  Revised Definition of the GMPLS Switching Capability and Type Fields

Abstract

   GMPLS provides control for multiple switching technologies and for
   hierarchical switching within a technology.  GMPLS routing and
   signaling use common values to indicate the type of switching
   technology.  These values are carried in routing protocols via the
   Switching Capability field, and in signaling protocols via the
   Switching Type field.  While the values used in these fields are the
   primary indicators of the technology and hierarchy level being
   controlled, the values are not consistently defined and used across
   the different technologies supported by GMPLS.  This document is
   intended to resolve the inconsistent definition and use of the
   Switching Capability and Type fields by narrowly scoping the meaning
   and use of the fields.  This document updates all documents that use
   the GMPLS Switching Capability and Types fields, in particular RFCs
   3471, 4202, 4203, and 5307.

Status of This Memo

   This is an Internet Standards Track document.

   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 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7074.

Berger & Meuric              Standards Track                    [Page 1]
RFC 7074        GMPLS Switching and Type Fields Revision   November 2013

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1.  Introduction

   Generalized Multiprotocol Label Switching (GMPLS) provides control
   for multiple switching technologies.  It also supports hierarchical
   switching within a technology.  The original GMPLS Architecture, per
   [RFC3945], included support for five types of switching capabilities.
   An additional type was also defined in [RFC6002].  The switching
   types defined in these documents include:

   1. Packet Switch Capable (PSC)

   2. Layer-2 Switch Capable (L2SC)

   3. Time-Division Multiplex Capable (TDM)

   4. Lambda Switch Capable (LSC)

   5. Fiber-Switch Capable (FSC)

   6. Data Channel Switching Capable (DCSC)

   Support for the original types was defined for routing in [RFC4202],
   [RFC4203], and [RFC5307], where the types were represented in the
   Switching Capability (Switching Cap) field.  In general, hierarchy
   within a type is addressed in a type-specific fashion, and a single
   Switching Capability field value is defined per type.  The exception
   to this is PSC, which was assigned four values to indicate four
   levels of hierarchy: PSC-1, PSC-2, PSC-3, and PSC-4.  The same values
   used in routing are defined for signaling in [RFC3471], and are
   carried in the Switching Type field.  Following the IANA registry, we
   refer to the values used in the routing Switching Capability field
   and signaling Switching Type field as Switching Types.

Berger & Meuric              Standards Track                    [Page 2]
RFC 7074        GMPLS Switching and Type Fields Revision   November 2013

   In general, a Switching Type does not indicate a specific data-plane
   technology; this needs to be inferred from context.  For example,
   L2SC was defined to cover Ethernet and ATM, and TDM was defined to
   cover both SONET/SDH [RFC4606] and G.709 [RFC4328].  The basic
   assumption was that different technologies of the same type would
   never operate within the same control, i.e., signaling and routing
   domains.