Network Working Group

Internet Engineering Task Force (IETF)                       Y. Lee, Ed.
Internet Draft                                      Huawei Technologies

Intended status: Standard
Request for Comments: 8780                           Samsung Electronics
Category: Standards Track                               R. Casellas, Ed.
Expires: September 1, 2019
ISSN: 2070-1721                                                     CTTC

                                                          March 1, 2019

PCEP
                                                               July 2020

The Path Computation Element Communication Protocol (PCEP) Extension for WSON
   Wavelength Switched Optical Network (WSON) Routing and Wavelength
                            Assignment

                      draft-ietf-pce-wson-rwa-ext-17 (RWA)

Abstract

   This document provides the Path Computation Element communication Communication
   Protocol (PCEP) extensions for the support of Routing and Wavelength
   Assignment (RWA) in Wavelength Switched Optical Networks (WSON). (WSONs).
   Path provisioning in WSONs requires a routing and wavelength
   assignment (RWA) an RWA process.  From a path
   computation perspective, wavelength assignment is the process of
   determining which wavelength can be used on each hop of a path and
   forms an additional routing constraint to optical path computation.

Status of this 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 an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum
   (IETF).  It represents the consensus of six
   months the IETF community.  It has
   received public review and may be updated, replaced, or obsoleted has been approved for publication by other documents
   at any time.  It the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is inappropriate to use Internet-Drafts as
   reference material or to cite them other than as "work available in progress."

   The list Section 2 of RFC 7841.

   Information about the current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt
   The list status of Internet-Draft Shadow Directories can this document, any errata,
   and how to provide feedback on it may be accessed obtained at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on September 1, 2019.
   https://www.rfc-editor.org/info/rfc8780.

Copyright Notice

   Copyright (c) 2019 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info)
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Terminology....................................................3  Introduction
   2. Requirements Language..........................................3  Terminology
   3. Introduction...................................................3  Requirements Language
   4.  Encoding of a an RWA Path Request.................................6 Request
     4.1.  Wavelength Assignment (WA) Object.........................7 Object
     4.2.  Wavelength Selection TLV..................................9 TLV
     4.3.  Wavelength Restriction Constraint TLV.....................9 TLV
       4.3.1.  Link Identifier Field...............................12 Field
       4.3.2.  Wavelength Restriction Field........................14 Constraint Field
     4.4.  Signal Processing Capability Restrictions................15 Restrictions
       4.4.1.  Signal Processing Exclusion.........................16 Exclusion
       4.4.2.  Signal Processing Inclusion.........................18 Inclusion
   5.  Encoding of a an RWA Path Reply..................................19 Reply
     5.1.  Wavelength Allocation TLV................................19 TLV
     5.2.  Error Indicator..........................................20 Indicator
     5.3.  NO-PATH Indicator........................................21 Indicator
   6.  Manageability Considerations..................................22 Considerations
     6.1.  Control of Function and Policy...........................22 Policy
     6.2.  Liveness Detection and Monitoring........................22 Monitoring
     6.3.  Verifying Correct Operation..............................22 Operation
     6.4.  Requirements on Other Protocols and Functional Components22 Components
     6.5.  Impact on Network Operation..............................23 Operation
   7.  Security Considerations.......................................23 Considerations
   8.  IANA Considerations...........................................23 Considerations
     8.1.  New PCEP Object: Wavelength Assignment Object............23 Object
     8.2.  WA Object Flag Field.....................................23 Field
     8.3.  New PCEP TLV: Wavelength Selection TLV...................24 TLV
     8.4.  New PCEP TLV: Wavelength Restriction Constraint TLV......24 TLV
     8.5.  Wavelength Restriction Constraint TLV Action Values......25 Values
     8.6.  New PCEP TLV: Wavelength Allocation TLV..................25 TLV
     8.7.  Wavelength Allocation TLV Flag Field.....................25 Field
     8.8.  New PCEP TLV: Optical Interface Class List TLV...........26 TLV
     8.9.  New PCEP TLV: Client Signal TLV..........................26 Information TLV
     8.10. New No-Path Reasons.....................................27 Bit Flag for NO-PATH-VECTOR TLV
     8.11. New Error-Types and Error-Values........................27 Error-Values
     8.12. New Subobjects for the Exclude Route Object.............28 Object
     8.13. New Subobjects for the Include Route Object.............28 Object
     8.14. Request for Updated Note for LMP TE Link Object Class Type
      ..............................................................28
   9. Acknowledgments...............................................29
   10. References...................................................29
      10.1.  References
     9.1.  Normative References....................................29
      10.2. References
     9.2.  Informative References..................................30
   11. Contributors.................................................32 References
   Acknowledgments
   Contributors
   Authors' Addresses...............................................33 Addresses

1. Terminology

   This document uses  Introduction

   [RFC5440] specifies the terminology defined in [RFC4655], and
   [RFC5440].

2. Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3. Introduction

   [RFC5440] specifies the Path Computation Element (PCE) Communication
   Protocol (PCEP) for communications between a Path Computation Client
   (PCC) Path Computation Element Communication
   Protocol (PCEP) for communications between a Path Computation Client
   (PCC) and a PCE, or between two PCEs.  Such interactions include
   path computation requests Path
   Computation Requests (PCReqs) and path computation replies Path Computation Replies (PCReps)
   as well as notifications of specific states related to the use of a
   PCE in the context of Multiprotocol Label Switching (MPLS) and
   Generalized MPLS (GMPLS) Traffic Engineering. Engineering (TE).

   A PCC is said to be any network component that makes such a request
   and may be, for instance, an Optical Switching Element optical switching element within a
   Wavelength Division Multiplexing (WDM) network.  The PCE, itself, can
   be located anywhere within the network, network and may be within an optical
   switching element, a Network Management System (NMS) (NMS), or an
   Operational Support System (OSS), or it may be an independent network
   server.

   This document provides the PCEP extensions for the support of Routing
   and Wavelength Assignment (RWA) in Wavelength Switched Optical
   Networks (WSON) (WSONs) based on the requirements specified in [RFC6163] and
   [RFC7449].

   WSON refers to WDM based WDM-based optical networks in which switching is
   performed selectively based on the wavelength of an optical signal.
   The devices used in WSONs that are able to switch signals based on
   signal wavelength are known as Lambda Switch Capable (LSC).  WSONs
   can be transparent or translucent.  A transparent optical network is
   made up of optical devices that can switch but not convert from one
   wavelength to another, all within the optical domain.  On the other
   hand, translucent networks include 3R regenerators (Re-
   amplification, Re-shaping, Re-timing) (reamplification,
   reshaping, and retiming) that are sparsely placed.  The main function
   of the 3R regenerators is to convert one optical wavelength to
   another.

   A Lambda Switch Capable (LSC)

   An LSC Label Switched Path (LSP) may span one or several transparent
   segments, which are delimited by 3R regenerators typically with
   electronic regenerator and optional wavelength conversion.  Each
   transparent segment or path in WSON is referred to as an optical
   path.  An optical path may span multiple fiber links links, and the path
   should be assigned the same wavelength for each link.  In such a case, the
   optical path is said to satisfy the wavelength-continuity constraint.
   Figure 1 illustrates the relationship between a an LSC LSP and
   transparent segments (optical paths).

   +---+       +-----+       +-----+      +-----+         +-----+
   |   |I1     |     |       |     |      |     |       I2|     |
   |   |o------|     |-------[(3R) ]------|     |--------o|     |
   |   |       |     |       |     |      |     |         |     |
   +---+       +-----+       +-----+      +-----+         +-----+
       (X  LSC)     (LSC  LSC)    (LSC  LSC)     (LSC  X)
        <------->   <------->       <----->     <------->
        <-----------------------><---------------------->
         Transparent Segment         Transparent Segment
       <------------------------------------------------->
                              LSC LSP

       Figure 1 1: Illustration of a an LSC LSP and transparent segments Transparent Segments

   Note that two transparent segments within a WSON LSP do not need to
   operate on the same wavelength (due to the wavelength conversion
   capabilities).  Two optical channels that share a common fiber link
   cannot be assigned the same wavelength; Otherwise, otherwise, the two signals
   would interfere with each other.  Note that advanced additional
   multiplexing techniques such as polarization based polarization-based multiplexing are
   not addressed in this document since the physical layer physical-layer aspects are
   not currently standardized.  Therefore, assigning the proper
   wavelength on a path is an essential requirement in the optical path
   computation process.

   When a switching node has the ability to perform wavelength
   conversion, the wavelength-continuity constraint can be relaxed, and
   a LSC Label Switched Path (LSP)
   an LSP may use different wavelengths on different links along its
   route from origin to destination.  It is, however, to be noted that
   wavelength converters may be limited due to their relatively high
   cost, while the number of WDM channels that can be supported in a
   fiber is also limited.  As a WSON can be composed of network nodes
   that cannot perform wavelength conversion, nodes with limited
   wavelength conversion, and nodes with full wavelength conversion
   abilities, wavelength assignment is an additional routing constraint
   to be considered in all optical path computation.

   For example (see Figure 1), within a translucent WSON, a an LSC LSP may
   be established between interfaces I1 and I2, spanning 2 two transparent
   segments (optical paths) where the wavelength continuity constraint
   applies (i.e. (i.e., the same unique wavelength must be assigned to the LSP
   at each TE link of the segment).  If the LSC LSP induced a Forwarding
   Adjacency / TE link, the switching capabilities of the TE link would
   be (X X) X), where X refers to the switching capability of I1 and I2.
   For example, X can be Packet Switch Capable (PSC), Time Division Time-Division
   Multiplexing (TDM), etc.

   This document aligns with GMPLS extensions for PCEP [PCEP-GMPLS] [RFC8779] for generic properties such as
   label, label-set label set, and label assignment assignment, noting that a wavelength is a
   type of label.  Wavelength restrictions and constraints are also
   formulated in terms of labels per [RFC7579].

   The optical modulation properties, which are also referred to as
   signal compatibility, are already considered in the signaling in
   [RFC7581] and [RFC7688].  In order to improve the signal quality and
   limit some optical effects effects, several advanced modulation processing
   capabilities are used by the mechanisms specified in this document.
   These modulation capabilities contribute not only contribute to optical signal
   quality checks but also constrain the selection of sender and
   receiver, as they should have matching signal processing
   capabilities.  This document includes signal compatibility
   constraints as part of RWA path computation.  That is, the signal
   processing capabilities (e.g., modulation and Forward Error
   Correction (FEC)) indicated by means of optical interface class the Optical Interface Class
   (OIC) must be compatible between the sender and the receiver of the
   optical path across all optical elements.

   This document, however, does not address optical impairments as part
   of RWA path computation.  See [RFC6566] for the framework for optical
   impairments.

2.  Terminology

   This document uses the terminology defined in [RFC4655] and
   [RFC5440].

3.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

4.  Encoding of a an RWA Path Request

   Figure 2 shows one typical PCE based PCE-based implementation, which is
   referred to as the Combined Process (R&WA).  With this architecture,
   the two processes of routing and wavelength assignment are accessed
   via a single PCE.  This architecture is the base architecture
   specified in [RFC6163] [RFC6163], and the PCEP extensions that are specified in
   this document are based on this architecture.

                          +----------------------------+
            +-----+       |     +-------+     +--+     |
            |     |       |     |Routing|     |WA|     |
            | PCC |<----->|     +-------+     +--+     |
            |     |       |                            |
            +-----+       |             PCE            |
                          +----------------------------+

               Figure 2 2: Combined Process (R&WA) architecture Architecture

4.1.  Wavelength Assignment (WA) Object

   Wavelength allocation can be performed by the PCE by different
   means:

   (a) By means of of:

   (a)  Explicit Label Control [RFC3471] where the PCE allocates which
        label to use for each interface/node along the path.  The
        allocated labels MAY appear after an interface route subobject.

   (b) By means of a  A Label Set where the PCE provides a range of potential labels
        to allocate be allocated by each node along the path.

   Option (b) allows distributed label allocation (performed during
   signaling) to complete wavelength assignment.

   Additionally, given a range of potential labels to allocate, a PC
   Request PCReq
   SHOULD convey the heuristic / or mechanism used for the allocation.

   The

   Per [RFC5440], the format of a PCReq message per [RFC5440] after incorporating the
   Wavelength Assignment (WA) object is as follows:

   <PCReq Message> ::= <Common Header>

                          [<svec-list>]

                          <request-list>

   Where:

         <request-list>::=<request>[<request-list>]

         <request>::= <RP>
                      <END-POINTS>

                      <WA>

                      [other optional objects...]

   If the WA object is present in the request, it MUST be encoded after
   the END-POINTS object as defined in [PCEP-GMPLS]. [RFC8779].  The WA Object object is
   mandatory in this document.  Orderings for the other optional objects
   are irrelevant.

   For the WA object, the Object-Class is (TBD1) (To be assigned by IANA).

   WA 42, and the Object-Type is 1.

   The format of the WA object body is 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          Reserved             |            Flags            |M|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                                                               |
   //                            TLVs                             //
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                            Figure 3 3: WA Object

   o

   Reserved (16 bits):  Reserved for future use and SHOULD be zeroed and
      ignored on receipt.

   o

   Flags field (16 bits) bits):  One flag bit is allocated as follows:

     -

      M (Mode - 1 (1 bit):  Wavelength Allocation Mode.  The M bit is used to
         indicate the mode of wavelength assignment.  When the M bit is
         set to 1, this indicates that the label assigned by the PCE
         must be explicit.  That is, the selected way to convey the
         allocated wavelength is by means of Explicit Label Control for
         each hop of a computed LSP.  Otherwise (M bit is set to 0), the
         label assigned by the PCE need not be explicit (i.e., it can be
         suggested in the form of
        label set Label Set objects in the corresponding
         response, to allow distributed WA.  If M is 0, the PCE MUST
         return a Label Set Field as described in Section 2.6 of
         [RFC7579] in the response.  See Section 5 of this document for
         the encoding discussion of a Label Set Field in a PCRep
         message.

      All unused flags SHOULD be zeroed.  IANA is to create has created a new
      registry to manage the Flag Flags field of the WA object.

   o

   TLVs (variable). (variable):  In the TLVs field, the following two TLVs are
      defined.  At least one TLV MUST be present.

     -

      Wavelength Selection TLV: A TLV of  The type (TBD2) with of this TLV is 8, and it has a
         fixed length of 32 bits indicating bits.  This TLV indicates the wavelength
         selection.  See Section 4.2 for details.

     -

      Wavelength Restriction Constraint TLV: A TLV of  The type (TBD3)
        with of this TLV is 9, and it has
         a variable length indicating length.  This TLV indicates wavelength restrictions.
         See Section 4.3 for details.

4.2.  Wavelength Selection TLV

   The Wavelength Selection TLV is used to indicate the wavelength
   selection constraint in regard to the order of wavelength assignment
   to be returned by the PCE.  This TLV is only applied when the M bit
   is set in the WA Object object specified in Section 4.1.  This TLV MUST NOT
   be used when the M bit is cleared.

   The encoding of this TLV is specified as the Wavelength Selection
   Sub-TLV WavelengthSelection sub-
   TLV in Section 4.2.2 of [RFC7689].  IANA is to allocate has allocated a new TLV
   type, type
   for the Wavelength Selection TLV type (TBD2). (Type 8).

4.3.  Wavelength Restriction Constraint TLV

   For any request that contains a wavelength assignment, the requester
   (PCC) MUST specify a restriction on the wavelengths to be used.  This
   restriction is to be interpreted by the PCE as a constraint on the
   tuning ability of the origination laser transmitter or on any other
   maintenance related
   maintenance-related constraints.  Note that if the LSP LSC LSP spans
   different segments, the PCE must have mechanisms to know the
   tunability restrictions of the involved wavelength converters / converters/
   regenerators, e.g. e.g., by means of the Traffic Engineering Database
   (TED) either via either IGP or Network Management System (NMS). NMS.  Even if the PCE knows the tunability of
   the transmitter, the PCC must be able to apply additional constraints
   to the request.

   The format of the Wavelength Restriction Constraint TLV is as follows:

   <Wavelength Restriction Constraint> Restriction> ::=

                  (<Action> <Count> <Reserved>

                  <Link Identifiers> <Wavelength Restriction>)...

   Where Constraint>)...

   Where:

   <Link Identifiers> ::= <Link Identifier> [<Link Identifiers>]

   See Section 4.3.1. 4.3.1 for the encoding of the Link Identifiers Field. Identifier field.

   These fields (i.e., <Action>, <Link Identifiers> Identifiers>, and <Wavelength
   Restriction>,
   Constraint>, etc.)  MAY appear together more than once to be able to
   specify multiple actions and their restrictions.

   IANA is to allocate has allocated a new TLV type, type for the Wavelength Restriction
   Constraint TLV type (TBD3).
   (Type 9).

   The TLV data is defined 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Action        |    Count      |           Reserved            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Link Identifiers Field                         |
   //                          . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Wavelength Restriction Field Constraint                      |
   //                        . . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   ~                         . . . .                               ~
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | Action        |    Count      |           Reserved            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Link Identifiers Field                         |
   //                          . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Wavelength Restriction Field Constraint                      |
   //                        . . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 4 4: Wavelength Restriction Constraint TLV Encoding

   o

   Action (8 bits):

        o 0 -
      0:  Inclusive List indicates List.  Indicates that one or more link identifiers
         are included in the Link Set. Each identifies a separate link
         that is part of the set.

        o 1 -

      1:  Inclusive Range indicates 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.

        o 2-255 - For future use

      2-255:  Unassigned.

      IANA is to create has created a new registry to manage the Action values of the
      Wavelength Restriction Constraint TLV.

      If a PCE receives an unrecognized Action value, the PCE MUST send
      a
   PCErr PCEP Error (PCErr) message with a PCEP-ERROR Object (Error-Type=TBD8) object with Error-
      Type=27 and an
   Error-value (Error-value=3). Error-value=3.  See Section 5.2 for details.

      Note that "links" are assumed to be bidirectional.

   o

   Count (8 bits):
      The number of the link identifiers identifiers.

      Note that a PCC MAY add a Wavelength restriction that applies to
      all links by setting the Count field to zero and specifying just a
      set of wavelengths.

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

       o

   Reserved (16 bits):
      Reserved for future use and SHOULD be zeroed and ignored on
      receipt.

       o

   Link Identifiers:
      Identifies each link ID for which restriction is applied.  The
      length is dependent on the link format and the Count field.  See
      Section 4.3.1. 4.3.1 for encoding of the Link Identifier encoding.

       o field.

   Wavelength Restriction: Constraint:
      See Section 4.3.2. 4.3.2 for the encoding of the Wavelength
          Restriction Field encoding. Constraint
      field.

   Various encoding errors are possible with this TLV (e.g., not exactly
   two link identifiers with the range case, unknown identifier types,
   no matching link for a given identifier, etc.).  To indicate errors
   associated with this encoding, a PCEP speaker MUST send a PCErr
   message with Error-Type=TBD8 Error-Type=27 and Error-value=3.  See Section
   5.1 5.2 for the
   details.

4.3.1.  Link Identifier Field

   The link identifier Link Identifier field can be an IPv4 [RFC3630], IPv6 [RFC5329] [RFC5329],
   or unnumbered interface ID [RFC4203].

   <Link Identifier> ::=

               <IPv4 Address> | <IPv6 Address> | <Unnumbered IF ID>

   The encoding of each case is as follows:

      IPv4 Address Field 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Type = 1     |    Reserved  (24 bits)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | IPv4 address (4 bytes)                                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      IPv6

                        Figure 5: IPv4 Address Field

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Type = 2     |    Reserved  (24 bits)                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | IPv6 address (16 bytes)                                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | IPv6 address (continued)                                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | IPv6 address (continued)                                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   | IPv6 address (continued)                                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Unnumbered Interface ID

                        Figure 6: IPv6 Address Field

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Type = 3     |    Reserved (24 bits)                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        TE Node ID (32 bits)                   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        Interface ID (32 bits)                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

       o

              Figure 7: Unnumbered Interface ID Address Field

   Type (8 bits): It indicates  Indicates the type of the link identifier.

       o

   Reserved (24 bits):  Reserved for future use and SHOULD be zeroed and
      ignored on receipt.

       o

   Link Identifier:  When the Type field is 1, 4-bytes a 4-byte IPv4 address is
      encoded; when the Type field is 2, 16-bytes a 16-byte IPv6 address is
      encoded; and when the Type field is 3, a tuple of 4-bytes a 4-byte TE node
      ID and 4-bytes a 4-byte interface ID is encoded.

   The Type field is extensible and matches to the IANA "TE_LINK Object Class
   type name space (Value 11)" registry created for the Link Management
   Protocol (LMP) [RFC4204] for "TE Link
   Object Class Type name space": https://www.iana.org/assignments/lmp-
   parameters/lmp-parameters.xhtml#lmp-parameters-15. See Section 8.14
   for the request to update the (see [LMP-PARAM]).  IANA has added an
   introductory text of note before the aforementioned registry to note stating that the
   values have additional usage for the Link Identifier Type field.  See
   Section 8.14.

4.3.2.  Wavelength Restriction Constraint Field

   The Wavelength Restriction Field Constraint field of the Wavelength Restriction
   Constraint TLV is
   encoded as a Label Set field Field as specified in Section 2.6 in of [RFC7579]
   with the base label encoded as a 32 bit 32-bit LSC label, as defined in
   [RFC6205].  The Label Set format is repeated here for convenience,
   with the base label internal structure included.  See [RFC6205] for a
   description of Grid, C.S, Identifier Channel Spacing (C.S.), Identifier, and n, as
   well as and
   see [RFC7579] for the details of each action.

   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               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |Grid | C.S C.S.  |    Identifier   |              n                |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     Additional fields as necessary per action                 |
   |                                                               |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                   Figure 8: Wavelength Constraint Field

   Action (4 bits):

            0  -
      0:  Inclusive List
            1  -

      1:  Exclusive List

            2  -

      2:  Inclusive Range

            3  -

      3:  Exclusive Range

            4  -

      4:  Bitmap Set

   Num Labels (12 bits):
      It is generally the number of labels.  It has a specific meaning
      depending on the action value.

   Length (16 bits):
      It is the length in bytes of the entire Wavelength
   Restriction Constraint
      field.

   Identifier (9 bits):
      The Identifier is always set to 0.  If PCC receives the value of
      the identifier other than 0, it will ignore.

   See Sections 2.6.1 - 2.6.3 2.6.1-2.6.3 of [RFC7579] for details on additional field
   discussion for each action.

4.4.  Signal Processing Capability Restrictions

   Path computation for WSON includes the checking of signal processing
   capabilities at each interface against requested capability; the PCE
   MUST have mechanisms to know the signal processing capabilities at
   each interface, e.g. e.g., by means of the Traffic Engineering Database (TED) either via either IGP or Network Management System (NMS). NMS.
   Moreover, a PCC should be able to indicate additional restrictions to
   signal processing compatibility, either on either the endpoint or any given
   link.

   The supported signal processing capabilities considered in the RWA
   Information Model [RFC7446] are:

      o

   *  Optical Interface Class List

      o

   *  Bit Rate

      o

   *  Client Signal

   The Bit Rate bit rate restriction is already expressed in [PCEP-GMPLS] in the BANDWIDTH object. object
   in [RFC8779].

   In order to support the Optical Interface Class optical interface class information and the
   Client Signal information
   client signal information, new TLVs are introduced as endpoint-
   restriction endpoint
   restrictions in the END-POINTS type Generalized endpoint:

      o Endpoint:

   *  Client Signal Information TLV

      o

   *  Optical Interface Class List TLV

   The END-POINTS type generalized endpoint Generalized Endpoint is extended as follows:

   <endpoint-restriction> ::=
                         <LABEL-REQUEST> <label-restriction-list>

   <label-restriction-list> ::= <label-restriction>
                                [<label-restriction-list>]

   <label-restriction> ::= (<LABEL-SET>|
                           [<Wavelength Restriction Constraint>] Restriction>]
                           [<signal-compatibility-restriction>])
   Where

   Where:

   <signal-compatibility-restriction> ::=
       [<Optical Interface Class List>] [<Client Signal>] Signal Information>]

   The Wavelength Restriction Constraint TLV is defined in Section 4.3.

   A new TLV for the Optical Interface Class List TLV (TBD5) (Type 11) is
   defined, and defined; the
   encoding of the value part of the Optical Interface
   Class List this TLV is described in Section 4.1 of
   [RFC7581].

   A new TLV for the Client Signal Information TLV (TBD6) (Type 12) is defined,
   and defined; the
   encoding of the value part of the Client Signal Information this TLV is described in Section 4.2 of
   [RFC7581].

4.4.1.  Signal Processing Exclusion

   The PCC/PCE should be able to exclude particular types of signal
   processing along the path in order to handle client restriction or
   multi-domain path computation. [RFC5440]  [RFC5521] defines how the Exclude
   Route Object (XRO) subobject is used.  In this draft, document, we add two
   new XRO Signal Processing Exclusion Subobjects. subobjects.

   The first XRO subobject type (TBD9) (8) is the Optical Interface Class
   List Field List,
   which is defined 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |X|  Type=TBD9  Type=8     |     Length    |   Reserved    | Attribute     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   //              Optical Interface Class List                   //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 5 9: Optical Interface Class List XRO Subobject

   Refer to [RFC5521] for the definition definitions of X, Length Length, and Attribute.

   Type (7 bits):  The Type type of the Signaling Processing Exclusion Field.
   The TLV Type value (TBD9) is to be assigned by the field.
      IANA has assigned value 8 for the Optical Interface Class List XRO Subobject Type.
      subobject type.

   Reserved bits (8 bits) bits):  These are for future use and SHOULD be
      zeroed and ignored on receipt.

   The

   Attribute field (8 bits):  [RFC5521] defines several Attribute values; the
      only permitted Attribute values for this field are 0 (Interface)
      or 1 (Node).

   The

   Optical Interface Class List List:  This field is encoded as described in
      Section 4.1 of [RFC7581].

   The second XRO subobject type (TBD10) (9) is the Client Signal
   Information Information,
   which is defined 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |X|  Type=TBD10  Type=9     |     Length    |   Reserved    |  Attribute    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   //                Client Signal Information                    //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

             Figure 6 10: Client Signal Information XRO Subobject

   Refer to [RFC5521] for the definition definitions of X, Length Length, and Attribute.

   Type (7 bits):  The Type type of the Signaling Processing Exclusion Field.
   The TLV Type value (TBD10) is to be assigned by the field.
      IANA has assigned value 9 for the Client Signal Information XRO Subobject Type.
      subobject type.

   Reserved bits (8 bits) bits):  These are for future use and SHOULD be
      zeroed and ignored on receipt.

   The

   Attribute field (8 bits):  [RFC5521] defines several Attribute values; the
      only permitted Attribute values for this field are 0 (Interface)
      or 1 (Node).

   The

   Client Signal Information Information:  This field is encoded as described in
      Section 4.2 of [RFC7581].

   The XRO needs to support the new Signaling Processing Exclusion XRO
   Subobject
   subobject types:

         Type     XRO Subobject Type

         TBD9

      8:  Optical Interface Class List

         TBD10

      9:  Client Signal Information

4.4.2.  Signal Processing Inclusion

   Similar to the XRO subobject, the PCC/PCE should be able to include
   particular types of signal processing along the path in order to
   handle client restriction or multi-domain path computation.
   [RFC5440] defines how the Include Route Object (IRO) subobject is
   used.  In this draft, document, we add two new Signal Processing Inclusion
   Subobjects.
   subobjects.

   The IRO needs to support the new IRO Subobject subobject types (TBD11 (8 and
   TBD12) 9) for
   the PCEP IRO object [RFC5440]:

         Type     IRO Subobject Type
         TBD11

      8:  Optical Interface Class List

         TBD12

      9:  Client Signal Information

   The encoding of the Signal Processing Inclusion subobjects is similar
   to the process in Section 4.4.1 where the 'X' field is replaced with
   the 'L'
   field, field; all the other fields remains remain the same.  The 'L' field
   is described in [RFC3209].

5.  Encoding of a an RWA Path Reply

   This section provides the encoding of a an RWA Path Reply for a
   wavelength allocation request as discussed in Section 4.

5.1.  Wavelength Allocation TLV

   Recall that wavelength allocation can be performed by the PCE by
   different means:

   (a)  By
   means of of:

   (a)  Explicit Label Control (ELC) where the PCE allocates which label
        to use for each interface/node along the path.

   (b)  By means of a  A Label Set where the PCE provides a range of potential labels
        to allocate be allocated by each node along the path.

   Option (b) allows distributed label allocation (performed during
   signaling) to complete wavelength allocation.

   The type for the Wavelength Allocation TLV type is TBD4 (See 10 (see Section 8.4).
   Note that this TLV is used for both (a) and (b). (b) above.  The TLV data
   is defined 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
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            Reserved           |          Flag          Flags              |M|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       Link Identifier Field                         |
   //                          . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                    Allocated Wavelength(s)                    |
   //                        . . . .                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

               Figure 7 11: Wavelength Allocation TLV Encoding

   o

   Reserved (16 bits):  Reserved for future use.

   o

   Flags field (16 bits) bits):  One flag bit is allocated as follows:

      .

      M (Mode): 1 bit

      -  0 indicates (1 bit):  Wavelength Allocation Mode.

         0:  Indicates the allocation is under Explicit relies on the use of Label Control.
      -  1 indicates Sets.

         1:  Indicates the allocation is expressed in done using Explicit Label Sets.
            Control.

      IANA is to create has created a new registry to manage the Flag Flags field (TBD14) of the
      Wavelength Allocation TLV.

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

        o

   Link Identifier:  Identifies the interface to which the assignment
      wavelength(s) is applied.  See Section 4.3.1. 4.3.1 for encoding of the
      Link Identifier encoding.

        o field.

   Allocated Wavelength(s):  Indicates the allocated wavelength(s) to be
      associated with the Link Identifier. link identifier.  See Section 4.3.2 for
      encoding details.

   This TLV is carried in a PCRep message as an attribute Attribute TLV [RFC5420]
   in the Hop Attribute Subobjects subobjects [RFC7570] in the ERO Explicit Route
   Object (ERO) [RFC5440].

5.2.  Error Indicator

   To indicate errors associated with the RWA request, a new Error Type
   (TBD8) Error-Type
   27 (WSON RWA Error) and subsequent error-values Error-values are defined as
   follows for inclusion in the PCEP-ERROR Object:

   A new Error-Type (TBD8) and subsequent error-values are defined as
   follows:

      o Error-Type=TBD8; object:

   *  Error-Type=27; Error-value=1: if If a PCE receives a an RWA request and
      the PCE is not capable of processing the request due to
      insufficient memory, the PCE MUST send a PCErr message with a
      PCEP-ERROR Object (Error-Type=TBD8) object with Error-Type=27 and an Error-value (Error-
        value=1). Error-value=1.  The PCE
      stops processing the request.  The corresponding RWA request MUST
      be cancelled canceled at the PCC.

      o Error-Type=TBD8;

   *  Error-Type=27; Error-value=2: if If a PCE receives a an RWA request and
      the PCE is not capable of RWA computation, the PCE MUST send a
      PCErr message with a PCEP-ERROR Object (Error-Type=TBD8) object with Error-Type=27 and an Error-value (Error-value=2).
      Error-value=2.  The PCE stops processing the request.  The
      corresponding RWA computation MUST be
        cancelled canceled at the PCC.

      o Error-Type=TBD8;

   *  Error-Type=27; Error-value=3: if If a PCE receives a an RWA request and
      there are syntactical encoding errors (e.g., not exactly two link
      identifiers with the range case, unknown identifier types, no
      matching link for a given identifier, unknown Action value, etc.),
      the PCE MUST send a PCErr message with a PCEP-
        ERROR Object (Error-Type=TBD8) PCEP-ERROR object with
      Error-Type=27 and an Error-value (Error-
        value=3). Error-value=3.

5.3.  NO-PATH Indicator

   To communicate the reason(s) for not being able to find RWA for the
   path request, the NO-PATH object can be used in the corresponding
   response.  The format of the NO-PATH object body is defined in
   [RFC5440].  The object may contain a NO-PATH-VECTOR TLV to provide
   additional information about why a path computation has failed.

   One

   This document defines a new bit flag is defined to be carried in the Flags field
   in the NO-PATH-VECTOR TLV TLV, which is carried in the NO-PATH Object.

        o object:

   Bit TBD7: 23:  When set, the PCE indicates no feasible route was found that
      meets all the constraints (e.g., wavelength restriction, signal
      compatibility, etc.) associated with RWA.

6.  Manageability Considerations

   Manageability of WSON Routing and Wavelength Assignment (RWA) RWA with PCE must address the considerations in
   the following considerations: subsections.

6.1.  Control of Function and Policy

   In addition to the parameters already listed in Section 8.1 of
   [RFC5440], a PCEP implementation SHOULD allow configuration of the
   following PCEP session parameters on a PCC:

        o

   *  The ability to send a WSON RWA request.

   In addition to the parameters already listed in Section 8.1 of
   [RFC5440], a PCEP implementation SHOULD allow configuration of the
   following PCEP session parameters on a PCE:

        o

   *  The support for WSON RWA.

        o

   *  A set of WSON RWA specific WSON-RWA-specific policies (authorized sender, request
      rate limiter, etc).

   These parameters may be configured as default parameters for any PCEP
   session the PCEP speaker participates in, or they may apply to a
   specific session with a given PCEP peer or a specific group of
   sessions with a specific group of PCEP peers.

6.2.  Liveness Detection and Monitoring

   Mechanisms defined in this document do not imply any new liveness
   detection and monitoring requirements in addition to requirements, aside from those already
   listed in section Section 8.3 of [RFC5440].

6.3.  Verifying Correct Operation

   Mechanisms defined in this document do not imply any new verification requirements in addition to
   requirements, aside from those already listed in
   section Section 8.4 of [RFC5440]
   [RFC5440].

6.4.  Requirements on Other Protocols and Functional Components

   The PCEP Link-State mechanism [PCEP-LS] may be used to advertise WSON
   RWA path computation capabilities to PCCs.

6.5.  Impact on Network Operation

   Mechanisms defined in this document do not imply any new network
   operation requirements in addition to requirements, aside from those already listed in
   section
   Section 8.6 of [RFC5440].

7.  Security Considerations

   The security considerations discussed in [RFC5440] are relevant for
   this document, document; this document does not introduce any new security
   issues.  If an operator wishes to keep private the information distributed by WSON,
   WSON private, PCEPS (Usage of TLS to Provide a Secure Transport for
   PCEP) [RFC8253] SHOULD be used.

8.  IANA Considerations

   IANA maintains a registry of PCEP parameters.  IANA has made
   allocations from the sub-registries subregistries as described in the following
   sections.

8.1.  New PCEP Object: Wavelength Assignment Object

   As described in Section 4.1, a new PCEP Object object is defined to carry
   wavelength assignment related
   wavelength-assignment-related constraints.  IANA is to allocate has allocated the
   following from in the "PCEP Objects" sub-registry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-objects):

   Object Class subregistry [PCEP-NUMBERS]:

   +====================+======+==========================+===========+
   | Object-Class Value | Name  Object | Object-Type              | Reference
   Value                Type
   ---------------------------------------------------------

   TBD1 |
   +====================+======+==========================+===========+
   | 42                 | WA   | 0: Reserved              | RFC 8780  |
   +--------------------+------+--------------------------+-----------+
   |                    |      | 1: Wavelength Assignment   [This.I-D] | RFC 8780  |
   +--------------------+------+--------------------------+-----------+

                                 Table 1

8.2.  WA Object Flag Field

   As described in Section 4.1, IANA is to create a has created the "WA Object Flag
   Field" subregistry under the "Path Computation Element Protocol
   (PCEP) Numbers" registry [PCEP-NUMBERS] to manage the Flag Flags field of
   the WA object.  New values are to be assigned by Standards Action
   [RFC8126].  Each bit should be tracked with the following qualities:

       o

   *  Bit number (counting from bit 0 as the most significant bit)

       o

   *  Capability description

       o

   *  Defining RFC

   The following values are defined in initial contents of this document: registry are shown below.  One bit is defined has
   been allocated for the WA Object flag defined in this document:

   Codespace of the Flag field (WA Object)

   +======+============================+===========+
   | Bit  | Description                | Reference
   ------------------------------------------------- |
   +======+============================+===========+
   | 0-14 | Unassigned                    [This.I-D]                 |           |
   +------+----------------------------+-----------+
   | 15       Explicit Label Control        [This.I-D]   | Wavelength Allocation Mode | RFC 8780  |
   +------+----------------------------+-----------+

                        Table 2

8.3.  New PCEP TLV: Wavelength Selection TLV

   As described in Sections

   In Section 4.2, a new PCEP TLV is defined to indicate wavelength
   selection constraints.  IANA is to allocate this new TLV
   from has made the following allocation in the
   "PCEP TLV Type Indicators" subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
   indicators). [PCEP-NUMBERS]:

   +=======+======================+===========+
   | Value | Description          | Reference
   ---------------------------------------------------------
   TBD2 |
   +=======+======================+===========+
   | 8     | Wavelength Selection       [This.I-D] | RFC 8780  |
   +-------+----------------------+-----------+

                     Table 3

8.4.  New PCEP TLV: Wavelength Restriction Constraint TLV

   As described in Sections

   In Section 4.3, a new PCEP TLV is defined to indicate wavelength restriction constraints.
   restrictions.  IANA is to allocate this new TLV
   from has made the following allocation in the "PCEP
   TLV Type Indicators" subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
   indicators). [PCEP-NUMBERS]:

   +=======+========================+===========+
   | Value | Description            | Reference
   ---------------------------------------------------------
   TBD3 |
   +=======+========================+===========+
   | 9     | Wavelength Restriction     [This.I-D]
                     Constraint | RFC 8780  |
   +-------+------------------------+-----------+

                      Table 4

8.5.  Wavelength Restriction Constraint TLV Action Values

   As described in Section 4.3, IANA is to allocate a has created the new "Wavelength
   Restriction TLV Action Values" subregistry under the "Path
   Computation Element Protocol (PCEP) Numbers" registry [PCEP-NUMBERS]
   to manage the Action values of the Action field in of the Wavelength
   Restriction Constraint TLV.  New values are assigned by Standards Action
   [RFC8126].  Each value should be tracked with the following
   qualities: value, meaning, and defining RFC. The following values
   are defined in this document:

   *  Value

   *  Meaning              Reference

   ---------------------------------------------------------

   0                 Inclusive List       [This.I-D]

   1                 Inclusive

   *  Defining RFC

   The initial contents of this registry are shown below:

   +=======+=================+===========+
   | Value | Meaning         | Reference |
   +=======+=================+===========+
   | 0     | Inclusive List  | RFC 8780  |
   +-------+-----------------+-----------+
   | 1     | Inclusive Range      [This.I-D] | RFC 8780  |
   +-------+-----------------+-----------+
   | 2-255             Reserved             [This.I-D] | Unassigned      |           |
   +-------+-----------------+-----------+

                   Table 5

8.6.  New PCEP TLV: Wavelength Allocation TLV

   As described in

   In Section 5.1, a new PCEP TLV is defined to indicate the allocation
   of the wavelength(s) by the PCE in response to a request by the PCC.
   IANA is to allocate this new TLV from has made the following allocation in "PCEP TLV Type Indicators"
   subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
   indicators). [PCEP-NUMBERS]:

   +=======+=======================+===========+
   | Value | Description           | Reference
   ---------------------------------------------------------
   TBD4 |
   +=======+=======================+===========+
   | 10    | Wavelength Allocation      [This.I-D] | RFC 8780  |
   +-------+-----------------------+-----------+

                      Table 6

8.7.  Wavelength Allocation TLV Flag Field

   As described in Section 5.1, IANA is to allocate has created a new "Wavelength
   Allocation TLV Flag Field" subregistry under the "Path Computation
   Element Protocol (PCEP) Numbers" registry [PCEP-NUMBERS] to manage
   the Flag Flags field of the Wavelength Allocation TLV.  New values are to
   be assigned by Standards Action [RFC8126].  Each bit should be
   tracked with the following qualities:

     o

   *  Bit number (counting from bit 0 as the most significant bit)
     o

   *  Capability description

     o

   *  Defining RFC

   One bit is defined for the Wavelength Allocation flag defined in this -
   document:

   Codespace document.  The
   initial contents of the Flag field (Wavelength Allocation TLV) this registry are shown below:

   +======+============================+===========+
   | Bit  | Description                | Reference
   ------------------------------------------------- |
   +======+============================+===========+
   | 0-14 | Unassigned                    [This.I-D]                 |           |
   +------+----------------------------+-----------+
   | 15   | Wavelength Allocation Mode    [This.I-D] | RFC 8780  |
   +------+----------------------------+-----------+

                        Table 7

8.8.  New PCEP TLV: Optical Interface Class List TLV

   As described in

   In Section 4.4, a new PCEP TLV is defined to indicate the optical interface class list. Optical
   Interface Class List.  IANA is to allocate this new TLV
   from has made the following allocation in the
   "PCEP TLV Type Indicators" subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
   indicators). [PCEP-NUMBERS]:

   +=======+==============================+===========+
   | Value | Description                  | Reference
   ---------------------------------------------------------
   TBD5 |
   +=======+==============================+===========+
   | 11    | Optical Interface          [This.I-D] Class List | RFC 8780  |
   +-------+------------------------------+-----------+

                         Table 8

8.9.  New PCEP TLV: Client Signal Information TLV

   As described in

   In Section 4.4, a new PCEP TLV is defined to indicate the client signal information. Client
   Signal Information.  IANA is to allocate this new TLV from has made the following allocation in the
   "PCEP TLV Type Indicators" subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-tlv-type-
   indicators). [PCEP-NUMBERS]:

   +=======+===========================+===========+
   | Value | Description               | Reference
   ---------------------------------------------------------
   TBD6 |
   +=======+===========================+===========+
   | 12    | Client Signal Information  [This.I-D] | RFC 8780  |
   +-------+---------------------------+-----------+

                        Table 9

8.10.  New No-Path Reasons

   As described in Bit Flag for NO-PATH-VECTOR TLV

   In Section 5.3, a new bit flag are is defined to be carried in the Flags
   field in the NO-PATH-VECTOR TLV TLV, which is carried in the NO-PATH Object.
   object.  This flag, when set, indicates that no feasible route was
   found that meets all the RWA constraints (e.g., wavelength
   restriction, signal compatibility, etc.) associated with a an RWA path
   computation request.

   IANA is to allocate has made the following allocation for this new bit flag from in the "PCEP NO-PATH-VECTOR
   "NO-PATH-VECTOR TLV Flag Field" subregistry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#no-path-vector-
   tlv). [PCEP-NUMBERS]:

   +=====+========================+===========+
   | Bit | Description            | Reference
   -----------------------------------------------------
   TBD7 |
   +=====+========================+===========+
   | 23  | No RWA constraints met     [This.I-D] | RFC 8780  |
   +-----+------------------------+-----------+

                     Table 10

8.11.  New Error-Types and Error-Values

   As described in

   In Section 5.2, new PCEP error codes are defined for WSON RWA errors.
   IANA is to allocate from has made the following allocations in the ""PCEP-ERROR "PCEP-ERROR Object
   Error Types and Values" sub-registry
   (http://www.iana.org/assignments/pcep/pcep.xhtml#pcep-error-object).

   Error- subregistry [PCEP-NUMBERS]:

   +============+================+========================+===========+
   | Error-Type | Meaning           Error-Value        | Error-value            | Reference
   Type
   ---------------------------------------------------------------

   TBD8 |
   +============+================+========================+===========+
   | 27         | WSON RWA Error error | 0: Unassigned        [This.I-D]          | RFC 8780  |
   +------------+----------------+------------------------+-----------+
   |            |                | 1: Insufficient      [This.I-D]
                                    Memory memory | RFC 8780  |
   +------------+----------------+------------------------+-----------+
   |            |                | 2: RWA computation   [This.I-D]
                                    Not not | RFC 8780  |
   |            |                | supported              |           |
   +------------+----------------+------------------------+-----------+
   |            |                | 3: Syntactical       [This.I-D]
                                    Encoding         | RFC 8780  |
   |            |                | encoding error         |           |
   +------------+----------------+------------------------+-----------+
   |            |                | 4-255: Unassigned    [This.I-D]      | RFC 8780  |
   +------------+----------------+------------------------+-----------+

                                 Table 11

8.12.  New Subobjects for the Exclude Route Object

   As described in Section 4.4.1, the "PCEP Parameters"

   The "Path Computation Element Protocol (PCEP) Numbers" registry
   contains a subregistry "PCEP Objects" with an entry for the Exclude
   Route Object (XRO). titled "XRO Subobjects" [PCEP-NUMBERS].  Per
   Section 4.4.1, IANA is requested to add further has added the following subobjects that can be
   carried in the XRO as follows:

      Subobject      Type XRO:

   +=======+==============================+===========+
   | Value | Description                  | Reference

      ----------------------------------------------------------

      TBD9 |
   +=======+==============================+===========+
   | 8     | Optical Interface Class List     [This.I-D]

      TBD10 | RFC 8780  |
   +-------+------------------------------+-----------+
   | 9     | Client Signal Information        [This.I-D]    | RFC 8780  |
   +-------+------------------------------+-----------+

                         Table 12

8.13.  New Subobjects for the Include Route Object

   As described in Section 4.4.2, the "PCEP Parameters"

   The "Path Computation Element Protocol (PCEP) Numbers" registry
   contains a subregistry "PCEP Objects" with an entry for the Include
   Route Object (IRO). titled "IRO Subobjects" [PCEP-NUMBERS].  Per
   Section 4.4.2, IANA is requested to add further has added the following subobjects that can be
   carried in the IRO as follows:

      Subobject      Type IRO:

   +=======+==============================+===========+
   | Value | Description                  | Reference

      ----------------------------------------------------------

      TBD11 |
   +=======+==============================+===========+
   | 8     | Optical Interface Class List     [This.I-D]

      TBD12 | RFC 8780  |
   +-------+------------------------------+-----------+
   | 9     | Client Signal Information        [This.I-D]    | RFC 8780  |
   +-------+------------------------------+-----------+

                         Table 13

8.14.  Request for Updated Note for LMP TE Link Object Class Type

   As discussed in Section 4.3.1, the

   The "TE_LINK Object Class type name space (Value 11)" registry was
   created for the Link Management Protocol (LMP) [RFC4204] for "TE Link Object Class Type
   name space": https://www.iana.org/assignments/lmp-parameters/lmp-
   parameters.xhtml#lmp-parameters-15 is requested for [RFC4204].  As
   discussed in Section 4.3.1, IANA has added the updated
   introductory following note that at the
   top of the "TE_LINK Object Class type name space (Value 11)" registry
   [LMP-PARAM]:

      These values have additional usage for the Link Identifier Type
      field.

9. Acknowledgments

   The authors would like to thank Adrian Farrel, Julien Meuric, Dhruv
   Dhody and Benjamin Kaduk for many helpful comments that greatly
   improved the contents of this draft.

10.  References

10.1.

9.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997. 1997,
              <https://www.rfc-editor.org/info/rfc2119>.

   [RFC3209] D.  Awduche, L. D., Berger, D. L., Gan, T. D., Li, V. T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, DOI 10.17487/RFC3209, December 2001. 2001,
              <https://www.rfc-editor.org/info/rfc3209>.

   [RFC3630] D.  Katz, K. D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630,
              DOI 10.17487/RFC3630, September 2003. 2003,
              <https://www.rfc-editor.org/info/rfc3630>.

   [RFC5329]  Ishiguro, K., Manral, V., Davey, A., and A. Lindem, Ed.,
              "Traffic Engineering Extensions to OSPF Version 3",
              RFC 5329, DOI 10.17487/RFC5329, September 2008. 2008,
              <https://www.rfc-editor.org/info/rfc5329>.

   [RFC5440] JP.  Vasseur, Ed., JP., Ed. and JL. Le Roux, Ed., "Path Computation
              Element (PCE) Communication Protocol (PCEP)", RFC 5440,
              DOI 10.17487/RFC5440, March 2009. 2009,
              <https://www.rfc-editor.org/info/rfc5440>.

   [RFC6205] Tomohiro, O.  Otani, T., Ed. and D. Li, Ed., "Generalized Labels for Lambda-
             Switching Capable
              Lambda-Switch-Capable (LSC) Label Switching Routers",
              RFC 6205,
             January, 2011. DOI 10.17487/RFC6205, March 2011,
              <https://www.rfc-editor.org/info/rfc6205>.

   [RFC7570] C.  Margaria, et al., C., Ed., Martinelli, G., Balls, S., and B.
              Wright, "Label Switched Path (LSP) Attribute in the
              Explicit Route Object (ERO)", RFC 7570,
              DOI 10.17487/RFC7570, July 2015. 2015,
              <https://www.rfc-editor.org/info/rfc7570>.

   [RFC7579] G. Bernstein and Y.  Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
              J. Han, "General Network Element Constraint Encoding for GMPLS Controlled
              GMPLS-Controlled Networks", RFC 7579,
              DOI 10.17487/RFC7579, June 2015. 2015,
              <https://www.rfc-editor.org/info/rfc7579>.

   [RFC7581] G. Bernstein and Y.  Bernstein, G., Ed., Lee, Y., Ed., Li, D., Imajuku, W., and
              J. Han, "Routing and Wavelength Assignment Information
              Encoding for Wavelength Switched Optical Networks", RFC7581, June 2015.

   [RFC7689] Bernstein et al., "Signaling Extensions for Wavelength
             Switched Optical Networks",
              RFC 7689, November 2015. 7581, DOI 10.17487/RFC7581, June 2015,
              <https://www.rfc-editor.org/info/rfc7581>.

   [RFC7688] Y.  Lee, Y., Ed. and G. Bernstein, "OSPF Ed., "GMPLS OSPF
              Enhancement for Signal and Network Element Compatibility
              for Wavelength Switched Optical Networks", RFC 7688,
              DOI 10.17487/RFC7688, November 2015,
              <https://www.rfc-editor.org/info/rfc7688>.

   [RFC7689]  Bernstein, G., Ed., Xu, S., Lee, Y., Ed., Martinelli, G.,
              and H. Harai, "Signaling Extensions for Wavelength
              Switched Optical Networks", RFC 7689,
              DOI 10.17487/RFC7689, November 2015. 2015,
              <https://www.rfc-editor.org/info/rfc7689>.

   [RFC8174] B.  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017. 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8253] D.  Lopez, O. D., Gonzalez de Dios, Q. O., Wu, Q., and D. Dhody,
              "PCEPS: Usage of TLS to Provide a Secure Transport for the
              Path Computation Element Communication Protocol (PCEP)",
              RFC 8253, DOI 10.17487/RFC8253, October 2017.

   [PCEP-GMPLS] C. 2017,
              <https://www.rfc-editor.org/info/rfc8253>.

   [RFC8779]  Margaria, et al., "PCEP extensions C., Ed., Gonzalez de Dios, O., Ed., and F.
              Zhang, Ed., "Path Computation Element Communication
              Protocol (PCEP) Extensions for GMPLS",
             draft-ietf-pce-gmpls-pcep-extensions, work in progress.

10.2. RFC 8779,
              DOI 10.17487/RFC8779, July 2020,
              <https://www.rfc-editor.org/info/rfc8779>.

9.2.  Informative References

   [LMP-PARAM]
              IANA, "Link Management Protocol (LMP) Parameters",
              <https://www.iana.org/assignments/lmp-parameters/>.

   [PCEP-LS]  Lee, Y., Zheng, H., Ceccarelli, D., Wang, W., Park, P.,
              and B. Yoon, "PCEP Extension for Distribution of Link-
              State and TE information for Optical Networks", Work in
              Progress, Internet-Draft, draft-lee-pce-pcep-ls-optical-
              09, 9 March 2020, <https://tools.ietf.org/html/draft-lee-
              pce-pcep-ls-optical-09>.

   [PCEP-NUMBERS]
              IANA, "Path Computation Element Protocol (PCEP) Numbers",
              <https://www.iana.org/assignments/pcep/>.

   [RFC3471]  Berger, L. (Editor), L., Ed., "Generalized Multi-Protocol Label
              Switching (GMPLS) Signaling Functional Description",
              RFC
             3471. 3471, DOI 10.17487/RFC3471, January 2003. 2003,
              <https://www.rfc-editor.org/info/rfc3471>.

   [RFC4203] K.  Kompella, Ed., K., Ed. and Y. Rekhter, Ed., "OSPF Extensions in
              Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC 4203, DOI 10.17487/RFC4203, October 2005. 2005,
              <https://www.rfc-editor.org/info/rfc4203>.

   [RFC4204] J.  Lang, J., Ed., "Link Management Protocol (LMP)", RFC 4204,
              DOI 10.17487/RFC4204, October 2005. 2005,
              <https://www.rfc-editor.org/info/rfc4204>.

   [RFC4655] A.  Farrel, JP. A., Vasseur, G. J.-P., and J. Ash, "A Path
              Computation Element (PCE)-Based Architecture", RFC 4655,
              DOI 10.17487/RFC4655, August 2006. 2006,
              <https://www.rfc-editor.org/info/rfc4655>.

   [RFC5420]  Farrel, A., Ed., Papadimitriou, D., Vasseur, JP., and A.
              Ayyangar, "Encoding of Attributes for MPLS LSP
              Establishment Using Resource Reservation Protocol Traffic
              Engineering (RSVP-TE)", RFC5420, February 2009.

   [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
             Element (PCE) communication Protocol", RFC 5440, March
             2009.[RFC5521] 5420, DOI 10.17487/RFC5420,
              February 2009, <https://www.rfc-editor.org/info/rfc5420>.

   [RFC5521]  Oki, E, T. E., Takeda, T., and A. Farrel, "Extensions to the
              Path Computation Element Communication Protocol (PCEP) for
              Route Exclusions", RFC 5521, DOI 10.17487/RFC5521, April
             2009.
              2009, <https://www.rfc-editor.org/info/rfc5521>.

   [RFC6163]  Lee, Y. and Y., Ed., Bernstein, G. (Editors), G., Ed., and W. Imajuku,
              "Framework for GMPLS and PCE Path Computation Element (PCE)
              Control of Wavelength Switched Optical Networks", Networks (WSONs)",
              RFC 6163, March 2011. DOI 10.17487/RFC6163, April 2011,
              <https://www.rfc-editor.org/info/rfc6163>.

   [RFC6566]  Lee, Y. Y., Ed., Bernstein, G., Ed., Li, D., and Berstein, G. (Editors),
              Martinelli, "A Framework for the Control of Wavelength
              Switched Optical Networks (WSONs) with Impairments",
              RFC 6566, DOI 10.17487/RFC6566, March 2012. 2012,
              <https://www.rfc-editor.org/info/rfc6566>.

   [RFC7446] Y.  Lee, G. Y., Ed., Bernstein, (Editors), G., Ed., Li, D., and W. Imajuku,
              "Routing and Wavelength Assignment Information Model for
              Wavelength Switched Optical Networks", RFC 7446,
              DOI 10.17487/RFC7446, February 2015. 2015,
              <https://www.rfc-editor.org/info/rfc7446>.

   [RFC7449] Y.  Lee, G. Y., Ed., Bernstein, (Editors), G., Ed., Martensson, J., Takeda,
              T., Tsuritani, T., and O. Gonzalez de Dios, "Path
              Computation Element Communication Protocol (PCEP)
              Requirements for Wavelength Switched Optical Network
              (WSON) Routing and Wavelength Assignment", RFC 7449,
              DOI 10.17487/RFC7449, February 2015.

   [PCEP-LS] Y. Lee, et al., "PCEP Extension for Distribution of Link-
             State and TE information for Optical Networks", draft-lee-
             pce-pcep-ls-optical, work in progress. 2015,
              <https://www.rfc-editor.org/info/rfc7449>.

   [RFC8126] M.  Cotton, B. M., Leiba, T,.Narten, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017.

11. 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

Acknowledgments

   The authors would like to thank Adrian Farrel, Julien Meuric, Dhruv
   Dhody, and Benjamin Kaduk for many helpful comments that greatly
   improved the contents of this document.

Contributors

   Fatai Zhang
   Huawei Technologies

   Email: zhangfatai@huawei.com

   Cyril Margaria
   Nokia Siemens Networks
   St
   St. Martin Strasse 76
   Munich,
   81541 Munich
   Germany

   Phone: +49 89 5159 16934
   Email: cyril.margaria@nsn.com

   Oscar Gonzalez de Dios
   Telefonica Investigacion y Desarrollo
   C/ Emilio Vargas 6
   Madrid,
   28043 Madrid
   Spain

   Phone: +34 91 3374013
   Email: ogondio@tid.es

   Greg Bernstein
   Grotto Networking
   Fremont, CA, USA CA
   United States of America

   Phone: (510) 573-2237 +1 510 573 2237
   Email: gregb@grotto-networking.com

Authors' Addresses

   Young Lee, Editor
   Huawei Technologies
   5700 Tennyson Parkway Suite 600
   Plano, TX 75024, USA Lee (editor)
   Samsung Electronics

   Email: leeyoung@huawei.com younglee.tx@gmail.com

   Ramon Casellas, Editor (editor)
   CTTC PMT Ed B4 Av.
   Carl Friedrich Gauss 7
   PMT Ed B4 Av.
   08860 Castelldefels (Barcelona) Barcelona
   Spain

   Phone: (34) +34 936452916
   Email: ramon.casellas@cttc.es