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Network Working Group                                      G. Bernstein
Internet Draft                                        Grotto Networking
Intended status: Standards Track                                 Y. Lee
Expires: November 2013                                            D. Li
                                                                 Huawei
                                                             W. Imajuku
                                                                    NTT


                                                            May 6, 2013

     General Network Element Constraint Encoding for GMPLS Controlled
                                 Networks


             draft-ietf-ccamp-general-constraint-encode-11.txt


Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with
   the provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   This Internet-Draft will expire on November 6, 2013.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.






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   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 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.

Abstract

   Generalized Multiprotocol Label Switching can be used to control a
   wide variety of technologies. In some of these technologies network
   elements and links may impose additional routing constraints such as
   asymmetric switch connectivity, non-local label assignment, and
   label range limitations on links.

   This document provides efficient, protocol-agnostic encodings for
   general information elements representing connectivity and label
   constraints as well as label availability. It is intended that
   protocol-specific documents will reference this memo to describe how
   information is carried for specific uses.



Conventions used in this document

   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 RFC-2119 [RFC2119].

Table of Contents


   1. Introduction...................................................3
      1.1. Node Switching Asymmetry Constraints......................4
      1.2. Non-Local Label Assignment Constraints....................4
      1.3. Change Log................................................5
   2. Encoding.......................................................6
      2.1. Link Set Field............................................6
      2.2. Label Set Field...........................................8
         2.2.1. Inclusive/Exclusive Label Lists......................9
         2.2.2. Inclusive/Exclusive Label Ranges.....................9
         2.2.3. Bitmap Label Set....................................10
      2.3. Available Labels Sub-TLV.................................11



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      2.4. Shared Backup Labels Sub-TLV.............................11
      2.5. Connectivity Matrix Sub-TLV..............................12
      2.6. Port Label Restriction sub-TLV...........................13
         2.6.1. SIMPLE_LABEL........................................14
         2.6.2. CHANNEL_COUNT.......................................15
         2.6.3. LABEL_RANGE1........................................15
         2.6.4. SIMPLE_LABEL & CHANNEL_COUNT........................16
         2.6.5. Link Label Exclusivit...............................16
   3. Security Considerations.......................................17
   4. IANA Considerations...........................................17
   5. Acknowledgments...............................................17
   APPENDIX A: Encoding Examples....................................18
      A.1. Link Set Field...........................................18
      A.2. Label Set Field..........................................18
      A.3. Connectivity Matrix Sub-TLV..............................19
      A.4. Connectivity Matrix with Bi-directional Symmetry.........22
      A.5. Priority Flags in Available/Shared Backup Labels sub-TLV.24
   6. References....................................................26
      6.1. Normative References.....................................26
      6.2. Informative References...................................26
   7. Contributors..................................................28
   Authors' Addresses...............................................29
   Intellectual Property Statement..................................30
   Disclaimer of Validity...........................................30

1. Introduction

   Some data plane technologies that wish to make use of a GMPLS
   control plane contain additional constraints on switching capability
   and label assignment. In addition, some of these technologies must
   perform non-local label assignment based on the nature of the
   technology, e.g., wavelength continuity constraint in WSON [WSON-
   Frame]. Such constraints can lead to the requirement for link by
   link label availability in path computation and label assignment.

   This document provides efficient encodings of information needed by
   the routing and label assignment process in technologies such as
   WSON and are potentially applicable to a wider range of
   technologies. Such encodings can be used to extend GMPLS signaling
   and routing protocols. In addition these encodings could be used by
   other mechanisms to convey this same information to a path
   computation element (PCE).







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1.1. Node Switching Asymmetry Constraints

   For some network elements the ability of a signal or packet on a
   particular ingress port to reach a particular egress port may be
   limited. In addition, in some network elements the connectivity
   between some ingress ports and egress ports may be fixed, e.g., a
   simple multiplexer. To take into account such constraints during
   path computation we model this aspect of a network element via a
   connectivity matrix.

   The connectivity matrix (ConnectivityMatrix) represents either the
   potential connectivity matrix for asymmetric switches or fixed
   connectivity for an asymmetric device such as a multiplexer. Note
   that this matrix does not represent any particular internal blocking
   behavior but indicates which ingress ports and labels (e.g.,
   wavelengths) could possibly be connected to a particular output
   port. Representing internal state dependent blocking for a node is
   beyond the scope of this document and due to it's highly
   implementation dependent nature would most likely not be subject to
   standardization in the future. The connectivity matrix is a
   conceptual M by N matrix representing the potential switched or
   fixed connectivity, where M represents the number of ingress ports
   and N the number of egress ports.



1.2. Non-Local Label Assignment Constraints

   If the nature of the equipment involved in a network results in a
   requirement for non-local label assignment we can have constraints
   based on limits imposed by the ports themselves and those that are
   implied by the current label usage. Note that constraints such as
   these only become important when label assignment has a non-local
   character. For example in MPLS an LSR may have a limited range of
   labels available for use on an egress port and a set of labels
   already in use on that port and hence unavailable for use. This
   information, however, does not need to be shared unless there is
   some limitation on the LSR's label swapping ability. For example if
   a TDM node lacks the ability to perform time-slot interchange or a
   WSON lacks the ability to perform wavelength conversion then the
   label assignment process is not local to a single node and it may be
   advantageous to share the label assignment constraint information
   for use in path computation.

   Port label restrictions (PortLabelRestriction) model the label
   restrictions that the network element (node) and link may impose on



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   a port. These restrictions tell us what labels may or may not be
   used on a link and are intended to be relatively static. More
   dynamic information is contained in the information on available
   labels. Port label restrictions are specified relative to the port
   in general or to a specific connectivity matrix for increased
   modeling flexibility. Reference [Switch] gives an example where both
   switch and fixed connectivity matrices are used and both types of
   constraints occur on the same port.

1.3. Change Log

   Changes from 03 version:

   (a)  Removed informational BNF from section 1.

   (b)   Removed section on "Extension Encoding Usage Recommendations"

   Changes from 04,05 versions:

   No changes just refreshed document that was expiring.

   Changes from 06 version:

   Added priority information to available wavelength encodings.

   Changes from 07 version:

   In port label constraint changed reserved field to Switching
   Capability and Encoding to allow for self description of labels used
   and interface capability.

   Changes from 08 version:

   Switching Capability and Encoding applied to all sub-cases for Port
   Label Restriction sub-TLV in Section 2.6.

   Eliminated A (Availability) Bit from Available Labels Sub-TLV and
   Shared Backup Labels Sub-TLV.

   Changes from 09 version:

   Editorial change: Action field can be set to 0x01(Inclusive Range)
   for Link Set Field Encoding in Section 2.1.

   Changes from 10 version:




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   Editorial change: A.5 example was corrected to be consistent to
   Sections 2.3 and 2.4.





2. Encoding

   A type-length-value (TLV) encoding of the general connectivity and
   label restrictions and availability extensions is given in this
   section. This encoding is designed to be suitable for use in the
   GMPLS routing protocols OSPF [RFC4203] and IS-IS [RFC5307] and in
   the PCE protocol PCEP [PCEP]. Note that the information distributed
   in [RFC4203] and [RFC5307] is arranged via the nesting of sub-TLVs
   within TLVs and this document makes use of such constructs. First,
   however we define two general purpose fields that will be used
   repeatedly in the subsequent TLVs.



2.1. Link Set Field

   We will frequently need to describe properties of groups of links.
   To do so efficiently we can make use of a link set concept similar
   to the label set concept of [RFC3471]. This Link Set Field is used
   in the <ConnectivityMatrix> sub-TLV, which is defined in Section
   2.5.  The information carried in a Link Set is defined by:

       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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |    Action     |Dir|  Format   |         Length                |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Link Identifier 1                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      :                               :                               :
      :                               :                               :
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Link Identifier N                       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


     Action: 8 bits

         0 - Inclusive List



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   Indicates that one or more link identifiers are included in the Link
   Set. Each identifies a separate link that is part of the set.

         1 - Inclusive Range

   Indicates that the Link Set defines a range of links.  It contains
   two link identifiers. The first identifier indicates the start of
   the range (inclusive). The second identifier indicates the end of
   the range (inclusive). All links with numeric values between the
   bounds are considered to be part of the set. A value of zero in
   either position indicates that there is no bound on the
   corresponding portion of the range. Note that the Action field can
   be set to 0x01(Inclusive Range) only when unnumbered link identifier
   is used.

     Dir: Directionality of the Link Set (2 bits)

         0 -- bidirectional

         1 -- ingress

         2 -- egress

   For example in optical networks we think in terms of unidirectional
   as well as bidirectional links. For example, label restrictions or
   connectivity may be different for an ingress port, than for its
   "companion" egress port if one exists. Note that "interfaces" such
   as those discussed in the Interfaces MIB [RFC2863] are assumed to be
   bidirectional. This also applies to the links advertised in various
   link state routing protocols.

     Format: The format of the link identifier (6 bits)

         0 -- Link Local Identifier

   Indicates that the links in the Link Set are identified by link
   local identifiers. All link local identifiers are supplied in the
   context of the advertising node.

         1 -- Local Interface IPv4 Address

         2 -- Local Interface IPv6 Address

   Indicates that the links in the Link Set are identified by Local
   Interface IP Address. All Local Interface IP Address are supplied in
   the context of the advertising node.



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         Others TBD.

   Note that all link identifiers in the same list must be of the same
   type.

     Length: 16 bits

   This field indicates the total length in bytes of the Link Set field.

     Link Identifier: length is dependent on the link format

   The link identifier represents the port which is being described
   either for connectivity or label restrictions. This can be the link
   local identifier of [RFC4202], GMPLS routing, [RFC4203] GMPLS OSPF
   routing, and [RFC5307] IS-IS GMPLS routing. The use of the link
   local identifier format can result in more compact encodings when
   the assignments are done in a reasonable fashion.

2.2. Label Set Field

   Label Set Field is used within the <AvailableLabels> sub-TLV or the
   <SharedBackupLabels> sub-TLV, which is defined in Section 2.3. and
   2.4. ,respectively.

   The general format for a label set is given below. This format uses
   the Action concept from [RFC3471] with an additional Action to
   define a "bit map" type of label set. The second 32 bit field is a
   base label used as a starting point in many of the specific formats.

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | Action|    Num Labels         |          Length               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          Base Label                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Additional fields as necessary per action                 |
     |



   Action:

         0  - Inclusive List

         1  - Exclusive List



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         2  - Inclusive Range

         3  - Exclusive Range

         4  - Bitmap Set

   Num Labels is only meaningful for Action value of 4 (Bitmap Set). It
   indicates the number of labels represented by the bit map. See more
   detail in section 3.2.3.

   Length is the length in bytes of the entire field.

   2.2.1.                         Inclusive/Exclusive Label Lists

   In the case of the inclusive/exclusive lists the wavelength set
   format is given by:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 or 1 | Num Labels (not used) |          Length               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Base Label                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Last  Label                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where:

   Num Labels is not used in this particular format since the Length
   parameter is sufficient to determine the number of labels in the
   list.

   2.2.2.                         Inclusive/Exclusive Label Ranges

   In the case of inclusive/exclusive ranges the label set format is
   given by:









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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |2 or 3 | Num Labels(not used)  |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    Start Label                                |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     End Label                                 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



   Note that the start and end label must in some sense "compatible" in
   the technology being used.

   2.2.3.                         Bitmap Label Set

   In the case of Action = 4, the bitmap the label set format is given
   by:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  4    |   Num Labels          |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         Base Label                            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Bit Map Word #1 (Lowest numerical labels)                  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |    Bit Map Word #N (Highest numerical labels)                 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where Num Labels in this case tells us the number of labels
   represented by the bit map. Each bit in the bit map represents a
   particular label with a value of 1/0 indicating whether the label is
   in the set or not. Bit position zero represents the lowest label and
   corresponds to the base label, while each succeeding bit position
   represents the next label logically above the previous.

   The size of the bit map is Num Label bits, but the bit map is padded
   out to a full multiple of 32 bits so that the TLV is a multiple of
   four bytes. Bits that do not represent labels (i.e., those in




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   positions (Num Labels) and beyond SHOULD be set to zero and MUST be
   ignored.

2.3. Available Labels Sub-TLV

   The Available Labels sub-TLV link consists of priority flags, and a
   single variable length label set field as follows:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     PRI       |              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field                           |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where

   PRI (Priority Flags, 8 bits): Indicates priority level applied to
   Label Set Field. Bit 8 corresponds to priority level 0 and bit 15
   corresponds to priority level 7.

   Note that Label Set Field is defined in Section 2.2. See Appendix
   A.5. for illustrative examples.



2.4. Shared Backup Labels Sub-TLV

   The Shared Backup Labels sub-TLV consists of priority flags, and
   single variable length label set field as follows:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     PRI         |            Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field                           |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where




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   PRI (Priority Flags, 8 bits): Indicates priority level applied to
   Label Set Field. Bit 8 corresponds to priority level 0 and bit 15
   corresponds to priority level 7.





2.5. Connectivity Matrix Sub-TLV

   The Connectivity Matrix represents how ingress ports are connected
   to egress ports for network elements. The switch and fixed
   connectivity matrices can be compactly represented in terms of a
   minimal list of ingress and egress port set pairs that have mutual
   connectivity. As described in [Switch] such a minimal list
   representation leads naturally to a graph representation for path
   computation purposes that involves the fewest additional nodes and
   links.

   A TLV encoding of this list of link set pairs 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      | Connectivity  |   MatrixID    |             Reserved          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Link Set A #1                         |
      :                               :                               :
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                         Link Set B #1                         :
      :                               :                               :
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Additional Link set pairs as needed     |
      :                     to specify connectivity                   :
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where

   Connectivity is the device type.

         0 -- the device is fixed

         1 -- the device is switched(e.g., ROADM/OXC)





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   MatrixID represents the ID of the connectivity matrix and is an 8
   bit integer. The value of 0xFF is reserved for use with port
   wavelength constraints and should not be used to identify a
   connectivity matrix.

   Link Set A #1 and Link Set B #1 together represent a pair of link
   sets. There are two permitted combinations for the link set field
   parameter "dir" for Link Set A and B pairs:

   o  Link Set A dir=ingress, Link Set B dir=egress

     The meaning of the pair of link sets A and B in this case is that
     any signal that ingresses a link in set A can be potentially
     switched out of an egress link in set B.

   o  Link Set A dir=bidirectional, Link Set B dir=bidirectional

      The meaning of the pair of link sets A and B in this case is that
      any signal that ingresses on the links in set A can potentially
      egress on a link in set B, and any ingress signal on the links in
      set B can potentially egress on a link in set A.

   See Appendix A for both types of encodings as applied to a ROADM
   example.


2.6. Port Label Restriction sub-TLV

   Port Label Restriction tells us what labels may or may not be used
   on a link.

   The port label restriction of section 1.2.  can be encoded as a sub-
   TLV as follows. More than one of these sub-TLVs may be needed to
   fully specify a complex port constraint. When more than one of these
   sub-TLVs are present the resulting restriction is the intersection
   of the restrictions expressed in each sub-TLV. To indicate that a
   restriction applies to the port in general and not to a specific
   connectivity matrix use the reserved value of 0xFF for the MatrixID.











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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |   MatrixID    |RestrictionType| Switching Cap |     Encoding  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |     Additional Restriction Parameters per RestrictionType    |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   Where:

   MatrixID: either is the value in the corresponding Connectivity
   Matrix sub-TLV or takes the value OxFF to indicate the restriction
   applies to the port regardless of any Connectivity Matrix.

   RestrictionType can take the following values and meanings:

         0: SIMPLE_LABEL  (Simple label selective restriction)

         1: CHANNEL_COUNT (Channel count restriction)

         2: LABEL_RANGE1 (Label range device with a movable center
         label and width)

         3: SIMPLE_LABEL & CHANNEL_COUNT (Combination of SIMPLE_LABEL
         and CHANNEL_COUNT restriction. The accompanying label set and
         channel count indicate labels permitted on the port and the
         maximum number of channels that can be simultaneously used on
         the port)

         4: LINK_LABEL_EXCLUSIVITY (A label may be used at most once
         amongst a set of specified ports)

   Switching Capability is defined in [RFC4203] and Encoding in
   [RFC3471]. The combination of these fields defines the type of
   labels used in specifying the port label restrictions as well as the
   interface type to which these restrictions apply.

   2.6.1.                         SIMPLE_LABEL

   In the case of the SIMPLE_LABEL the GeneralPortRestrictions (or
   MatrixSpecificRestrictions) format is given by:






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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | MatrixID      | RstType = 0   | Switching Cap |   Encoding    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Label Set Field                     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   In this case the accompanying label set indicates the labels
   permitted on the port.


   2.6.2.                         CHANNEL_COUNT

   In the case of the CHANNEL_COUNT the format is given by:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | MatrixID      | RstType = 1   | Switching Cap |   Encoding    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        MaxNumChannels                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   In this case the accompanying MaxNumChannels indicates the maximum
   number of channels (labels) that can be simultaneously used on the
   port/matrix.


   2.6.3.                         LABEL_RANGE1

   In the case of the LABEL_RANGE1 the GeneralPortRestrictions (or
   MatrixSpecificRestrictions) format is given by:















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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | MatrixID      | RstType = 2   |Switching Cap |   Encoding     |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          MaxLabelRange                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        Label Set Field                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   In this case the accompanying MaxLabelRange indicates the maximum
   range of the labels. The corresponding label set is used to indicate
   the overall label range. Specific center label information can be
   obtained from dynamic label in use information. It is assumed that
   both center label and range tuning can be done without causing
   faults to existing signals.


   2.6.4.                         SIMPLE_LABEL & CHANNEL_COUNT

   In the case of the SIMPLE_LABEL & CHANNEL_COUNT the format is given
   by:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | MatrixID      | RstType = 3   | Switching Cap |   Encoding    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        MaxNumChannels                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        Label Set Field                        |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   In this case the accompanying label set and MaxNumChannels indicate
   labels permitted on the port and the maximum number of labels that
   can be simultaneously used on the port.

   2.6.5.                         Link Label Exclusivity

   In the case of the Link Label Exclusivity the format is given by:







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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     | MatrixID      | RstType = 4   | Switching Cap |   Encoding    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                        Link Set Field                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


   In this case the accompanying port set indicate that a label may be
   used at most once among the ports in the link set field.



3. Security Considerations

   This document defines protocol-independent encodings for WSON
   information and does not introduce any security issues.

   However, other documents that make use of these encodings within
   protocol extensions need to consider the issues and risks associated
   with, inspection, interception, modification, or spoofing of any of
   this information. It is expected that any such documents will
   describe the necessary security measures to provide adequate
   protection.

4. IANA Considerations

   TBD. Once our approach is finalized we may need identifiers for the
   various TLVs and sub-TLVs.

5. Acknowledgments

   This document was prepared using 2-Word-v2.0.template.dot.















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APPENDIX A: Encoding Examples

   Here we give examples of the general encoding extensions applied to
   some simple ROADM network elements and links.

A.1. Link Set Field

   Suppose that we wish to describe a set of ingress ports that are
   have link local identifiers number 3 through 42. In the link set
   field we set the Action = 1 to denote an inclusive range; the Dir =
   1 to denote ingress links; and, the Format = 0 to denote link local
   identifiers. In particular we have:

     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Action=1     |0 1|0 0 0 0 0 0|             Length = 12       |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Link Local Identifier = #3                |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Link Local Identifier = #42               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


A.2. Label Set Field

   Example:

   A 40 channel C-Band DWDM system with 100GHz spacing with lowest
   frequency 192.0THz (1561.4nm) and highest frequency 195.9THz
   (1530.3nm). These frequencies correspond to n = -11, and n = 28
   respectively. Now suppose the following channels are available:

   Frequency (THz)       n Value      bit map position
   --------------------------------------------------
      192.0             -11                  0
      192.5              -6                  5
      193.1               0                 11
      193.9               8                 19
      194.0               9                 20
      195.2              21                 32
      195.8              27                 38

   With the Grid value set to indicate an ITU-T G.694.1 DWDM grid, C.S.
   set to indicate 100GHz this lambda bit map set would then be encoded
   as follows:





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      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  4    | Num Wavelengths = 40  |    Length = 16 bytes          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = -11 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 0 0 0 0 0 1 0|   Not used in 40 Channel system (all zeros)   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   To encode this same set as an inclusive list we would have:

      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  0    | Num Wavelengths = 40  |    Length = 20 bytes          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = -11 |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = -6  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = -0  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = 8   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = 9   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = 21  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |Grid |  C.S. |      Reserved   | n  for lowest frequency = 27  |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+




A.3. Connectivity Matrix Sub-TLV

   Example:

   Suppose we have a typical 2-degree 40 channel ROADM. In addition to
   its two line side ports it has 80 add and 80 drop ports. The picture
   below illustrates how a typical 2-degree ROADM system that works
   with bi-directional fiber pairs is a highly asymmetrical system
   composed of two unidirectional ROADM subsystems.



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                         (Tributary) Ports #3-#42
                     Ingress added to    Egress dropped from
                     West Line Egress    East Line Ingress
                           vvvvv          ^^^^^
                          | |||.|       | |||.|
                    +-----| |||.|--------| |||.|------+
                    |    +----------------------+     |
                    |    |                      |     |
        Egress      |    | Unidirectional ROADM |     |    Ingress
   -----------------+    |                      |     +--------------
   <=====================|                      |===================<
   -----------------+    +----------------------+     +--------------
                    |                                 |
        Port #1     |                                 |   Port #2
   (West Line Side) |                                 |(East Line Side)
   -----------------+    +----------------------+     +--------------
   >=====================|                      |===================>
   -----------------+    | Unidirectional ROADM |     +--------------
        Ingress     |    |                      |     |    Egress
                    |    |              _       |     |
                    |    +----------------------+     |
                    +-----| |||.|--------| |||.|------+
                          | |||.|        | |||.|
                           vvvvv          ^^^^^
                     (Tributary) Ports #43-#82
                Egress dropped from    Ingress added to
                West Line ingress      East Line egress


   Referring to the figure we see that the ingress direction of ports
   #3-#42 (add ports) can only connect to the egress on port #1. While
   the ingress side of port #2 (line side) can only connect to the
   egress on ports #3-#42 (drop) and to the egress on port #1 (pass
   through). Similarly, the ingress direction of ports #43-#82 can only
   connect to the egress on port #2 (line). While the ingress direction
   of port #1 can only connect to the egress on ports #43-#82 (drop) or
   port #2 (pass through). We can now represent this potential
   connectivity matrix as follows. This representation uses only 30 32-
   bit words.








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     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |    Conn = 1   |    MatrixID   |      Reserved                 |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                          Note: adds to line
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |0 1|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #3                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #42               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |1 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line to drops
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 1|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |1 0|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #3                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #42               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line to line
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 1|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |1 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                Note: adds to line
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |0 1|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #43               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



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    |                     Link Local Identifier = #82               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |1 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line to drops
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 1|0 0 0 0 0 0||          Length = 8          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |1 0|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #43               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #82               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line to line
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 1|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |1 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


A.4. Connectivity Matrix with Bi-directional Symmetry

   If one has the ability to renumber the ports of the previous example
   as shown in the next figure then we can take advantage of the bi-
   directional symmetry and use bi-directional encoding of the
   connectivity matrix. Note that we set dir=bidirectional in the link
   set fields.












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                                (Tributary)
                     Ports #3-42         Ports #43-82
                     West Line Egress    East Line Ingress
                           vvvvv          ^^^^^
                          | |||.|        | |||.|
                    +-----| |||.|--------| |||.|------+
                    |    +----------------------+     |
                    |    |                      |     |
        Egress      |    | Unidirectional ROADM |     |    Ingress
   -----------------+    |                      |     +--------------
   <=====================|                      |===================<
   -----------------+    +----------------------+     +--------------
                    |                                 |
        Port #1     |                                 |   Port #2
   (West Line Side) |                                 |(East Line Side)
   -----------------+    +----------------------+     +--------------
   >=====================|                      |===================>
   -----------------+    | Unidirectional ROADM |     +--------------
        Ingress     |    |                      |     |    Egress
                    |    |              _       |     |
                    |    +----------------------+     |
                    +-----| |||.|--------| |||.|------+
                          | |||.|        | |||.|
                           vvvvv          ^^^^^
                     Ports #3-#42            Ports #43-82
                Egress dropped from    Ingress added to
                West Line ingress      East Line egress






















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     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
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |    Conn = 1   |    MatrixID   |      Reserved                 |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                          Add/Drops #3-42 to Line side #1
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |0 0|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #3                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #42               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line #2 to add/drops #43-82
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=1     |0 0|0 0 0 0 0 0|          Length = 12          |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #43               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #82               |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                       Note: line to line
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #1                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |  Action=0     |0 0|0 0 0 0 0 0|          Length = 8           |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    |                     Link Local Identifier = #2                |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


A.5. Priority Flags in Available/Shared Backup Labels sub-TLV

   If one wants to make a set of labels (indicated by Label Set Field
   #1) available only for highest priority level (Priority Level 0)
   while allowing a set of labels (indicated by Label Set Field #2)



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   available to all priority levels (Priority Level 7), the following
   encoding will express such need.



      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |0 0 0 1 0 0 0 0|              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field #1                        |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |1 1 1 1 0 0 0 0|              Reserved                         |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     Label Set Field #2                        |
     :                                                               :
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+































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6. References

6.1. Normative References

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2863] McCloghrie, K. and F. Kastenholz, "The Interfaces Group
             MIB", RFC 2863, June 2000.

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

   [G.694.1] ITU-T Recommendation G.694.1, "Spectral grids for WDM
             applications: DWDM frequency grid", June, 2002.

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

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



6.2. Informative References

   [G.694.1] ITU-T Recommendation G.694.1, Spectral grids for WDM
             applications: DWDM frequency grid, June 2002.

   [G.694.2] ITU-T Recommendation G.694.2, Spectral grids for WDM
             applications: CWDM wavelength grid, December 2003.

   [RFC5307] Kompella, K., Ed., and Y. Rekhter, Ed., "IS-IS Extensions
             in Support of Generalized Multi-Protocol Label Switching
             (GMPLS)", RFC 5307, October 2008.









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   [Switch] G. Bernstein, Y. Lee, A. Gavler, J. Martensson, " Modeling
         WDM Wavelength Switching Systems for Use in GMPLS and
         Automated Path Computation", Journal of Optical Communications
         and Networking, vol. 1, June, 2009, pp. 187-195.

   [PCEP]    Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
             Element (PCE) communication Protocol (PCEP) - Version 1",
             RFC5440.









































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7. Contributors

   Diego Caviglia
   Ericsson
   Via A. Negrone 1/A 16153
   Genoa Italy

   Phone: +39 010 600 3736
   Email: diego.caviglia@(marconi.com, ericsson.com)

   Anders Gavler
   Acreo AB
   Electrum 236
   SE - 164 40 Kista Sweden

   Email: Anders.Gavler@acreo.se

   Jonas Martensson
   Acreo AB
   Electrum 236
   SE - 164 40 Kista, Sweden

   Email: Jonas.Martensson@acreo.se

   Itaru Nishioka
   NEC Corp.
   1753 Simonumabe, Nakahara-ku, Kawasaki, Kanagawa 211-8666
   Japan

   Phone: +81 44 396 3287
   Email: i-nishioka@cb.jp.nec.com

   Rao Rajan
   Infinera

   Email: rrao@infinera.com

   Giovanni Martinelli
   CISCO

   Email: giomarti@cisco.com


   Remi Theillaud
   Marben



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   remi.theillaud@marben-products.com


Authors' Addresses

   Greg M. Bernstein (ed.)
   Grotto Networking
   Fremont California, USA

   Phone: (510) 573-2237
   Email: gregb@grotto-networking.com


   Young Lee (ed.)
   Huawei Technologies
   1700 Alma Drive, Suite 100
   Plano, TX 75075
   USA

   Phone: (972) 509-5599 (x2240)
   Email: ylee@huawei.com


   Dan Li
   Huawei Technologies Co., Ltd.
   F3-5-B R&D Center, Huawei Base,
   Bantian, Longgang District
   Shenzhen 518129 P.R.China

   Phone: +86-755-28973237
   Email: danli@huawei.com

   Wataru Imajuku
   NTT Network Innovation Labs
   1-1 Hikari-no-oka, Yokosuka, Kanagawa
   Japan

   Phone: +81-(46) 859-4315
   Email: imajuku.wataru@lab.ntt.co.jp










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   Jianrui Han
   Huawei Technologies Co., Ltd.
   F3-5-B R&D Center, Huawei Base,
   Bantian, Longgang District
   Shenzhen 518129 P.R.China

   Phone: +86-755-28972916
   Email: hanjianrui@huawei.com


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Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.













































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