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Network Working Group                                         I. Bryskin
Request for Comments: 4397                        Independent Consultant
Category: Informational                                        A. Farrel
                                                      Old Dog Consulting
                                                           February 2006


   A Lexicography for the Interpretation of Generalized Multiprotocol
     Label Switching (GMPLS) Terminology within the Context of the
   ITU-T's Automatically Switched Optical Network (ASON) Architecture

Status of This Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   Generalized Multiprotocol Label Switching (GMPLS) has been developed
   by the IETF to facilitate the establishment of Label Switched Paths
   (LSPs) in a variety of data plane technologies and across several
   architectural models.  The ITU-T has specified an architecture for
   the control of Automatically Switched Optical Networks (ASON).

   This document provides a lexicography for the interpretation of GMPLS
   terminology within the context of the ASON architecture.

   It is important to note that GMPLS is applicable in a wider set of
   contexts than just ASON.  The definitions presented in this document
   do not provide exclusive or complete interpretations of GMPLS
   concepts.  This document simply allows the GMPLS terms to be applied
   within the ASON context.














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RFC 4397                GMPLS ASON Lexicography            February 2006


Table of Contents

   1. Introduction ....................................................3
   2. Terminology .....................................................3
      2.1. GMPLS Terminology Sources ..................................3
      2.2. ASON Terminology Sources ...................................4
      2.3. Common Terminology Sources .................................4
   3. Lexicography ....................................................4
      3.1. Network Presences ..........................................4
      3.2. Resources ..................................................5
      3.3. Layers .....................................................6
      3.4. Labels .....................................................7
      3.5. Data Links .................................................7
      3.6. Link Interfaces ............................................8
      3.7. Connections ................................................9
      3.8. Switching, Termination, and Adaptation Capabilities .......10
      3.9. TE Links and FAs ..........................................11
      3.10. TE Domains ...............................................13
      3.11. Component Links and Bundles ..............................13
      3.12. Regions ..................................................14
   4. Guidance on the Application of this Lexicography ...............14
   5. Management Considerations ......................................15
   6. Security Considerations ........................................15
   7. Acknowledgements ...............................................15
   8. Normative References ...........................................16
   9. Informative References .........................................16

























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1.  Introduction

   Generalized Multiprotocol Label Switching (GMPLS) has been developed
   by the IETF to facilitate the establishment of Label Switched Paths
   (LSPs) in a variety of data plane technologies such as Packet
   Switching Capable (PSC), Layer Two Switching Capable (L2SC), Time
   Division Multiplexing (TDM), Lambda Switching Capable (LSC), and
   Fiber Switching Capable (FSC).

   The ITU-T has specified an architecture for the control of
   Automatically Switched Optical Networks (ASON).  This architecture
   forms the basis of many Recommendations within the ITU-T.

   Because the GMPLS and ASON architectures were developed by different
   people in different standards bodies, and because the architectures
   have very different historic backgrounds (the Internet, and transport
   networks respectively), the terminology used is different.

   This document provides a lexicography for the interpretation of GMPLS
   terminology within the context of the ASON architecture.  This allows
   GMPLS documents to be generally understood by those familiar with
   ASON Recommendations.  The definitions presented in this document do
   not provide exclusive or complete interpretations of the GMPLS
   concepts.

2.  Terminology

   Throughout this document, angle brackets ("<" and ">") are used to
   indicate the context in which a term applies.  For example, "<Data
   Plane>" as part of a description of a term means that the term
   applies within the data plane.

2.1.  GMPLS Terminology Sources

   GMPLS terminology is principally defined in [RFC3945].  Other
   documents provide further key definitions including [RFC4201],
   [RFC4202], [RFC4204], and [RFC4206].

   The reader is recommended to become familiar with these other
   documents before attempting to use this document to provide a more
   general mapping between GMPLS and ASON.

   For details of GMPLS signaling, please refer to [RFC3471] and
   [RFC3473].  For details of GMPLS routing, please refer to [RFC4203]
   and [RFC4205].






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2.2.  ASON Terminology Sources

   The ASON architecture is specified in ITU-T Recommendation G.8080
   [G-8080].  This is developed from generic functional architectures
   and requirements specified in [G-805], [G-807], and [G-872].  The
   ASON terminology is defined in several Recommendations in the ASON
   family such as [G-8080], [G-8081], [G-7713], [G-7714], and [G-7715].
   The reader must be familiar with these documents before attempting to
   apply the lexicography set out in this document.

2.3.  Common Terminology Sources

   The work in this document builds on the shared view of ASON
   requirements and requirements expressed in [RFC4139], [RFC4258], and
   [RFC4394].

3.  Lexicography

3.1.  Network Presences

3.1.1.  GMPLS Terms

   Transport node <Data Plane> is a logical network device that is
      capable of originating and/or terminating of a data flow and/or
      switching it on the route to its destination.

   Controller <Control Plane> is a logical entity that models all
      control plane intelligence (routing, traffic engineering (TE), and
      signaling protocols, path computation, etc.).  A single controller
      can manage one or more transport nodes.  Separate functions (such
      as routing and signaling) may be hosted at distinct sites and
      hence could be considered as separate logical entities referred
      to, for example, as the routing controller, the signaling
      controller, etc.

   Label Switching Router (LSR) <Control & Data Planes> is a logical
      combination of a transport node and the controller that manages
      the transport node.  Many implementations of LSRs collocate all
      control plane and data plane functions associated with a transport
      node within a single physical presence making the term LSR
      concrete rather than logical.

      In some instances, the term LSR may be applied more loosely to
      indicate just the transport node or just the controller function
      dependent on the context.

   Node <Control & Data Planes> is a synonym for an LSR.




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   Control plane network <Control Plane> is an IP network used for
      delivery of control plane (protocol) messages exchanged by
      controllers.

3.1.2.  ASON Terms

   A GMPLS transport node is an ASON network element.

   A GMPLS controller is the set of ASON functional components
   controlling a given ASON network element (or partition of a network
   element).  In ASON, this set of functional components may exist in
   one place or multiple places.

   A GMPLS node is the combination of an ASON network element (or
   partition of a network element) and its associated control
   components.

   The GMPLS control plane network is the ASON Signaling Communication
   Network (SCN).  Note that both routing and signaling exchanges are
   carried by the SCN.

3.2.  Resources

3.2.1.  GMPLS Terms

   Non-packet-based resource <Data Plane> is a channel of a certain
      bandwidth that could be allocated in a network data plane of a
      particular technology for the purpose of user traffic delivery.
      Examples of non-packet-based resources are timeslots, lambda
      channels, etc.

   Packet-based resource <Data Plane> is an abstraction hiding the means
      related to the delivery of traffic with particular parameters
      (most importantly, bandwidth) with particular quality of service
      (QoS) over PSC media.  Examples of packet-based resources are
      forwarding queues, schedulers, etc.

   Layer Resource (Resource) <Data Plane>.  A non-packet-based data
      plane technology may yield resources in different network layers
      (see section 3.3).  For example, some TDM devices can operate with
      VC-12 timeslots, some with VC-4 timeslots, and some with VC4-4c
      timeslots.  There are also multiple layers of packet-based
      resources (i.e., one per label in the label stack).  Therefore, we
      define layer resource (or simply resource) irrespective of the
      underlying data plane technology as a basic data plane construct.
      It is defined by a combination of a particular data encoding type





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      and a switching/terminating bandwidth granularity.  Examples of
      layer resources are: PSC1, PSC4, ATM VP, ATM VC, Ethernet, VC-12,
      VC-4, Lambda 10G, and Lambda 40G.

   These three definitions give rise to the concept of Resource Type.
   Although not a formal term, this is useful shorthand to identify how
   and where a resource can be used dependent on the switching type,
   data encoding type, and switching/terminating bandwidth granularity
   (see section 3.8).

   All other descriptions provided in this memo are tightly bound to the
   resource.

3.2.2.  ASON Terms

   ASON terms for resource:

   - In the context of link discovery and resource management
     (allocation, binding into cross-connects, etc.), a GMPLS resource
     is one end of a link connection.

   - In the context of routing, path computation, and signaling, a GMPLS
     resource is a link connection or trail termination.

   Resource type is identified by a client CI (Characteristics
   Information) that could be carried by the resource.

3.3.  Layers

3.3.1.  GMPLS Terms

   Layer <Data Plane> is a set of resources of the same type that could
      be used for establishing a connection or used for connectionless
      data delivery.

   Note.  In GMPLS, the existence of non-blocking switching function in
   a transport node in a particular layer is modeled explicitly as one
   of the functions of the link interfaces connecting the transport node
   to its data links.

   A GMPLS layer is not the same as a GMPLS region.  See section 3.12.

3.3.2.  ASON Terms

   A GMPLS layer is an ASON layer network.






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RFC 4397                GMPLS ASON Lexicography            February 2006


3.4.  Labels

3.4.1.  GMPLS Terms

   Label <Control Plane> is an abstraction that provides an identifier
      for use in the control plane in order to identify a transport
      plane resource.

3.4.2.  ASON Terms

      A GMPLS label is the portion of an ASON SNP name that follows the
      SNPP name.

3.5.  Data Links

3.5.1.  GMPLS Terms

   Unidirectional data link end <Data Plane> is a set of resources that
      belong to the same layer and that could be allocated for the
      transfer of traffic in that layer from a particular transport node
      to the same neighboring transport node in the same direction.  A
      unidirectional data link end is connected to a transport node by
      one or more link interfaces (see section 3.6).

   Bidirectional data link end <Data Plane> is an association of two
      unidirectional data link ends that exist in the same layer and
      that could be used for the transfer of traffic in that layer
      between a particular transport node and the same neighbor in both
      directions.  A bidirectional data link end is connected to a
      transport node by one or more link interfaces (see section 3.6).

   Unidirectional data link <Data Plane> is an association of two
      unidirectional data link ends that exist in the same layer, that
      are connected to two transport nodes adjacent in that layer, and
      that could be used for the transfer of traffic between the two
      transport nodes in one direction.

   Bidirectional data link <Data Plane> is an association of two
      bidirectional data link ends that exist in the same layer, that
      are connected to two transport nodes adjacent in that layer, and
      that could be used for the transfer of traffic between the two
      transport nodes in both directions.









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RFC 4397                GMPLS ASON Lexicography            February 2006


3.5.2.  ASON Terms

   A GMPLS unidirectional data link end is a collection of connection
   points from the same client layer that are supported by a single
   trail termination (access point).

   A GMPLS data link is an ASON link supported by a single server trail.

3.6.  Link Interfaces

3.6.1.  GMPLS Terms

   Unidirectional link interface <Data Plane> is an abstraction that
      connects a transport node to a unidirectional data link end and
      represents (hides) the data plane intelligence like switching,
      termination, and adaptation in one direction.  In GMPLS, link
      interfaces are often referred to as "GMPLS interfaces" and it
      should be understood that these are data plane interfaces and the
      term does not refer to the ability of a control plane interface to
      handle GMPLS protocols.

      A single unidirectional data link end could be connected to a
      transport node by multiple link interfaces with one of them, for
      example, realizing switching function, while others realize the
      function of termination/adaptation.

   Bidirectional link interface <Data Plane> is an association of two or
      more unidirectional link interfaces that connects a transport node
      to a bidirectional data link end and represents the data plane
      intelligence like switching, termination, and adaptation in both
      directions.

   Link interface type <Data Plane> is identified by the function the
      interface provides.  There are three distinct functions --
      switching, termination, and adaptation; hence, there are three
      types of link interface.  Thus, when a Wavelength Division
      Multiplexing (WDM) link can do switching for some lambda channels,
      and termination and TDM OC48 adaptation for some other lambda
      channels, we say that the link is connected to the transport node
      by three interfaces each of a separate type: switching,
      termination, and adaptation.

3.6.2.  ASON Terms

   A GMPLS interface is the set of trail termination and adaptation
   functions between one or more server layer trails and a specific
   client layer subnetwork (which commonly is a matrix in a network
   element).



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   The GMPLS interface type may be identified by the ASON adapted client
   layer, or by the terminated server layer, or a combination of the
   two, depending on the context.  In some cases, a GMPLS interface
   comprises a set of ASON trail termination/adaptation functions, for
   which some connection points are bound to trail terminations and
   others to matrices.

3.7.  Connections

3.7.1.  GMPLS Terms

   In GMPLS a connection is known as a Label Switched Path (LSP).

   Unidirectional LSP (connection) <Data Plane> is a single resource or
      a set of cross-connected resources of a particular layer that
      could deliver traffic in that layer between a pair of transport
      nodes in one direction.

   Unidirectional LSP (connection) <Control Plane> is the signaling
      state necessary to maintain a unidirectional data plane LSP.

   Bidirectional LSP (connection) <Data Plane> is an association of two
      unidirectional LSPs (connections) that could simultaneously
      deliver traffic in a particular layer between a pair of transport
      nodes in opposite directions.

      In the context of GMPLS, both unidirectional constituents of a
      bidirectional LSP (connection) take identical paths in terms of
      data links, are provisioned concurrently, and require a single
      (shared) control state.

   Bidirectional LSP (connection) <Control Plane> is the signaling state
      necessary to maintain a bidirectional data plane LSP.

   LSP (connection) segment <Data Plane> is a single resource or a set
      of cross-connected resources that constitutes a segment of an LSP
      (connection).

3.7.2.  ASON Terms

   A GMPLS LSP (connection) is an ASON network connection.

   A GMPLS LSP segment is an ASON serial compound link connection.








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RFC 4397                GMPLS ASON Lexicography            February 2006


3.8.  Switching, Termination, and Adaptation Capabilities

3.8.1.  GMPLS Terms

   Switching capability <Data Plane> is a property (and defines a type)
      of a link interface that connects a particular data link to a
      transport node.  This property/type characterizes the interface's
      ability to cooperate with other link interfaces connecting data
      links within the same layer to the same transport node for the
      purpose of binding resources into cross-connects.  Switching
      capability is advertised as an attribute of the TE link local end
      associated with the link interface.

   Termination capability <Data Plane> is a property of a link interface
      that connects a particular data link to a transport node.  This
      property characterizes the interface's ability to terminate
      connections within the layer that the data link belongs to.

   Adaptation capability <Data Plane> is a property of a link interface
      that connects a particular data link to a transport node.  This
      property characterizes the interface's ability to perform a
      nesting function -- to use a locally terminated connection that
      belongs to one layer as a data link for some other layer.

   The need for advertisement of adaptation and termination capabilities
   within GMPLS has been recognized, and work is in progress to
   determine how these will be advertised.  It is likely that they will
   be advertised as a single combined attribute, or as separate
   attributes of the TE link local end associated with the link
   interface.

3.8.2.  ASON Terms

   In ASON applications:

   The GMPLS switching capability is a property of an ASON link end
   representing its association with a matrix.

   The GMPLS termination capability is a property of an ASON link end
   representing potential binding to a termination point.

   The GMPLS adaptation capability is a property of an ASON link end
   representing potential adaptation to/from a client layer network.








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3.9.  TE Links and FAs

3.9.1.  GMPLS Terms

   TE link end <Control Plane> is a grouping for the purpose of
      advertising and routing of resources of a particular layer.

      Such a grouping allows for decoupling of path selection from
      resource assignment.  Specifically, a path could be selected in a
      centralized way in terms of TE link ends, while the resource
      assignment (resource reservation and label allocation) could be
      performed in a distributed way during the connection setup.  A TE
      link end may reflect zero, one or more data link ends in the data
      plane.  A TE link end is associated with exactly one layer.

   TE link <Control Plane> is a grouping of two TE link ends associated
      with two neighboring transport nodes in a particular layer.

      In contrast to a data link, which provides network flexibility in
      a particular layer and, therefore, is a "real" topological
      element, a TE link is a logical routing element.  For example, an
      LSP path is computed in terms of TE links (or more precisely, in
      terms of TE link ends), while the LSP is provisioned over (that
      is, resources are allocated from) data links.

   Virtual TE link is a TE link associated with zero data links.

   TE link end advertising <Control Plane>.  A controller managing a
      particular transport node advertises local TE link ends.  Any
      controller in the TE domain makes a TE link available for its
      local path computation if it receives consistent advertisements of
      both TE link ends.  Strictly speaking, there is no such thing as
      TE link advertising -- only TE link end advertising.  TE link end
      advertising may contain information about multiple switching
      capabilities.  This, however, should not be interpreted as
      advertising of a multi-layer TE link end, but rather as joint
      advertisement of ends of multiple parallel TE links, each
      representing resources in a separate layer.  The advertisement may
      contain attributes shared by all TE links in the group (for
      example, protection capabilities, Shared Risk Link Groups (SRLGs),
      etc.), separate information related to each TE link (for example,
      switching capability, data encoding, unreserved bandwidth, etc.)
      as well as information related to inter-layer relationships of the
      advertised resources (for example, termination and adaptation
      capabilities) should the control plane decide to use them as the
      termination points of higher-layer data links.  These higher-layer
      data links, however, are not real yet -- they are abstract until
      the underlying connections are established in the lower layers.



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      LSPs created in lower layers for the purpose of providing data
      links (extra network flexibility) in higher layers are called
      hierarchical connections or LSPs (H-LSPs), or simply hierarchies.
      LSPs created for the purpose of providing data links in the same
      layer are called stitching segments.  H-LSPs and stitching
      segments could, but do not have to, be advertised as TE links.
      Naturally, if they are advertised as TE links (LSPs advertised as
      TE links are often referred to as TE-LSPs), they are made
      available for path computations performed on any controller within
      the TE domain into which they are advertised.  H-LSPs and
      stitching segments could be advertised either individually or in
      TE bundles.  An H-LSP or a stitching segment could be advertised
      as a TE link either into the same or a separate TE domain compared
      to the one within which it was provisioned.

      A set of H-LSPs that is created (or could be created) in a
      particular layer to provide network flexibility (data links) in
      other layers is called a Virtual Network Topology (VNT).  A single
      H-LSP could provide several (more than one) data links (each in a
      different layer).

   Forwarding Adjacency (FA) <Control Plane> is a TE link that does not
      require a direct routing adjacency (peering) between the
      controllers managing its ends in order to guarantee control plane
      connectivity (a control channel) between the controllers.  An
      example of an FA is an H-LSP or stitching segment advertised as a
      TE link into the same TE domain within which it was dynamically
      provisioned.  In such cases, the control plane connectivity
      between the controllers at the ends of the H-LSP/stitching segment
      is guaranteed by the concatenation of control channels
      interconnecting the ends of each of its constituents.  In
      contrast, an H-LSP or stitching segment advertised as a TE link
      into a TE domain (different than one where it was provisioned)
      generally requires a direct routing adjacency to be established
      within the TE domain where the TE link is advertised in order to
      guarantee control plane connectivity between the TE link ends.
      Therefore, is not an FA.

3.9.2.  ASON Terms

   The ITU term for a TE link end is Subnetwork Point (SNP) pool (SNPP).

   The ITU term for a TE link is SNPP link.

   The ITU term for an H-LSP is trail.






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3.10.  TE Domains

3.10.1 GMPLS Terms

   TE link attribute is a parameter of the set of resources associated
      with a TE link end that is significant in the context of path
      computation.

   Full TE visibility is a situation when a controller receives all
      unmodified TE advertisements from every other controller in a
      particular set of controllers.

   Limited TE visibility is a situation when a controller receives
      summarized TE information, or does not receive TE advertisements
      from at least one of a particular set of controllers.

   TE domain is a set of controllers each of which has full TE
      visibility within the set.

   TE database (TED) is a memory structure within a controller that
      contains all TE advertisements generated by all controllers within
      a particular TE domain.

   Vertical network integration is a set of control plane mechanisms and
      coordinated data plane mechanisms that span multiple layers.  The
      control plane mechanisms exist on one or more controllers and
      operate either within a single control plane instance or between
      control plane instances.  The data plane mechanisms consist of
      collaboration and adaptation between layers within a single
      transport node.

   Horizontal network integration is a set of control plane mechanisms
      and coordinated data plane mechanisms that span multiple TE
      domains within the same layer.  The control plane mechanisms exist
      on one or more controllers and operate either within a single
      control plane instance or between control plane instances.  The
      data plane mechanisms consist of collaboration between TE domains.

3.11.  Component Links and Bundles

3.11.1.  GMPLS Terms

   Component link end <Control Plane> is a grouping of resources of a
      particular layer that is not advertised as an individual TE link
      end.  A component link end could represent one or more data link
      ends or any subset of resources that belong to one or more data
      link ends.




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   Component link <Control Plane> is a grouping of two or more component
      link ends associated with neighboring transport nodes (that is,
      directly interconnected by one or more data links) in a particular
      layer.  Component links are equivalent to TE links except that the
      component link ends are not advertised separately.

   TE bundle <Control Plane> is an association of several parallel (that
      is, connecting the same pair of transport nodes) component links
      whose attributes are identical or whose differences are
      sufficiently negligible that the TE domain can view the entire
      association as a single TE link.  A TE bundle is advertised in the
      same way as a TE link, that is, by representing the associated
      component link ends as a single TE link end (TE bundle end) which
      is advertised.

3.12.  Regions

3.12.1.  GMPLS Terms

   TE region <Control Plane> is a set of one or more layers that are
      associated with the same type of data plane technology.  A TE
      region is sometimes called an LSP region or just a region.
      Examples of regions are: IP, ATM, TDM, photonic, fiber switching,
      etc.  Regions and region boundaries are significant for the
      signaling sub-system of the control plane because LSPs are
      signaled substantially differently (i.e., use different signaling
      object formats and semantics) in different regions.  Furthermore,
      advertising, routing, and path computation could be performed
      differently in different regions.  For example, computation of
      paths across photonic regions requires a wider set of constraints
      (e.g., optical impairments, wavelength continuity, etc) and needs
      to be performed in different terms (e.g., in terms of individual
      resources -- lambda channels, rather than in terms of TE links)
      compared to path computation in other regions like IP or TDM.

4.  Guidance on the Application of this Lexicography

   As discussed in the introduction to this document, this lexicography
   is intended to bring the concepts and terms associated with GMPLS
   into the context of the ITU-T's ASON architecture.  Thus, it should
   help those familiar with ASON to see how they may use the features
   and functions of GMPLS in order to meet the requirements of an ASON.
   For example, service providers wishing to establish a protected end-
   to-end service might read [SEG-PROT] and [E2E-PROT] and wish to
   understand how the GMPLS terms used relate to the ASON architecture
   so that they can confirm that they will satisfy their requirements.





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   This lexicography should not be used in order to obtain or derive
   definitive definitions of GMPLS terms.  To obtain definitions of
   GMPLS terms that are applicable across all GMPLS architectural
   models, the reader should refer to the RFCs listed in the references
   sections of this document.  [RFC3945] provides an overview of the
   GMPLS architecture and should be read first.

5.  Management Considerations

   Both GMPLS and ASON networks require management.  Both GMPLS and ASON
   specifications include considerable efforts to provide operator
   control and monitoring, as well as Operations and Management (OAM)
   functionality.

   These concepts are, however, out of scope of this document.

6.  Security Considerations

   Security is also a significant requirement of both GMPLS and ASON
   architectures.

   Again, however, this informational document is intended only to
   provide a lexicography, and the security concerns are, therefore, out
   of scope.

7.  Acknowledgements

   The authors would like to thank participants in the IETF's CCAMP
   working group and the ITU-T's Study Group 15 for their help in
   producing this document.  In particular, all those who attended the
   Study Group 15 Question 14 Interim Meeting in Holmdel, New Jersey
   during January 2005.  Further thanks to all participants of Study
   Group 15 Questions 12 and 14 who have provided valuable discussion,
   feedback and suggested text.

   Many thanks to Ichiro Inoue for his useful review and input, and to
   Scott Brim and Dimitri Papadimitriou for lengthy and constructive
   discussions.  Ben Mack-Crane and Jonathan Sadler provided very
   helpful reviews and discussions of ASON terms.  Thanks to Deborah
   Brungard and Kohei Shiomoto for additional review comments.











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8.  Normative References

   [RFC3945]        Mannie, E., Ed., "Generalized Multi-Protocol Label
                    Switching (GMPLS) Architecture", RFC 3945, October
                    2004.

   [RFC4201]        Kompella, K., Rekhter, Y., and L. Berger, "Link
                    Bundling in MPLS Traffic Engineering (TE)", RFC
                    4201, October 2005.

   [RFC4202]        Kompella, K. and Y. Rekhter, "Routing Extensions in
                    Support of Generalized Multi-Protocol Label
                    Switching (GMPLS)", RFC 4202, October 2005.

   [RFC4204]        Lang, J., Ed., "Link Management Protocol (LMP)", RFC
                    4204, October 2005.

   [RFC4206]        Kompella, K. and Y. Rekhter, "Label Switched Paths
                    (LSP) Hierarchy with Generalized Multi-Protocol
                    Label Switching (GMPLS) Traffic Engineering (TE)",
                    RFC 4206, October 2005.

9.  Informative References

   [RFC3471]        Berger, L., Ed., "Generalized Multi-Protocol Label
                    Switching (GMPLS) Signaling Functional Description",
                    RFC 3471, January 2003.

   [RFC3473]        Berger, L., Ed., "Generalized Multi-Protocol Label
                    Switching (GMPLS) Signaling Functional Description",
                    RFC 3471, January 2003.

   [RFC4139]        Papadimitriou, D., Drake, J., Ash, J., Farrel, A.,
                    and L. Ong, "Requirements for Generalized MPLS
                    (GMPLS) Signaling Usage and Extensions for
                    Automatically Switched Optical Network (ASON)", RFC
                    4139, July 2005.

   [RFC4203]        Kompella, K., Ed. and Y. Rekhter, Ed., "OSPF
                    Extensions in Support of Generalized Multi-Protocol
                    Label Switching (GMPLS)", RFC 4203, October 2005.

   [RFC4205]        Kompella, K., Ed. and Y. Rekhter, Ed., "Intermediate
                    System to Intermediate System (IS-IS) Extensions in
                    Support of Generalized Multi-Protocol Label
                    Switching (GMPLS)", RFC 4205, October 2005.





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   [RFC4258]        Brungard, D., Ed., "Requirements for Generalized
                    Multi-Protocol Label Switching (GMPLS) Routing for
                    the Automatically Switched Optical Network (ASON)",
                    RFC 4258, November 2005.

   [RFC4394]        Fedyk, D., Aboul-Magd, O., Brungard, D., Lang, J.,
                    and D. Papadimitriou, "A Transport Network View of
                    the Link Management Protocol (LMP)", RFC 4394,
                    February 2006.

   [E2E-PROT]       Lang, J., Ed., Rekhter, Y., Ed., and D.
                    Papadimitriou, D., Ed., "RSVP-TE Extensions in
                    support of End-to-End Generalized Multi-Protocol
                    Label Switching (GMPLS)-based Recovery", Work in
                    Progress, April 2005.

   [SEG-PROT]       Berger, L., Bryskin, I., Papadimitriou, D., and A.
                    Farrel, "GMPLS Based Segment Recovery", Work in
                    Progress, May 2005.

   For information on the availability of the following documents,
   please see http://www.itu.int.

   [G-8080]         ITU-T Recommendation G.8080/Y.1304, Architecture for
                    the automatically switched optical network (ASON).

   [G-805]          ITU-T Recommendation G.805 (2000), Generic
                    functional architecture of transport networks.

   [G-807]          ITU-T Recommendation G.807/Y.1302 (2001),
                    Requirements for the automatic switched transport
                    network (ASTN).

   [G-872]          ITU-T Recommendation G.872 (2001), Architecture of
                    optical transport networks.

   [G-8081]         ITU-T Recommendation G.8081 (2004), Terms and
                    definitions for Automatically Switched Optical
                    Networks (ASON).

   [G-7713]         ITU-T Recommendation G.7713 (2001), Distributed Call
                    and Connection Management.

   [G-7714]         ITU-T Recommendation G.7714 Revision (2005),
                    Generalized automatic discovery techniques.






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   [G-7715]         ITU-T Recommendation G.7715 (2002), Architecture and
                    Requirements for the Automatically Switched Optical
                    Network (ASON).

Authors' Addresses

   Igor Bryskin
   Independent Consultant

   EMail:  i_bryskin@yahoo.com


   Adrian Farrel
   Old Dog Consulting

   Phone:  +44 (0) 1978 860944
   EMail:  adrian@olddog.co.uk


































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Full Copyright Statement

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Acknowledgement

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