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Versions: (draft-dhodylee-pce-pcep-te-data-extn) 00 01 02 03 04 05 06 07 08 09 10 11 12 13

PCE Working Group                                               D. Dhody
Internet-Draft                                                    Y. Lee
Intended status: Standards Track                     Huawei Technologies
Expires: March 24, 2016                                    D. Ceccarelli
                                                                Ericsson
                                                      September 21, 2015


   PCEP Extension for Distribution of Link-State and TE Information.
                     draft-dhodylee-pce-pcep-ls-00

Abstract

   In order to compute and provide optimal paths, Path Computation
   Elements (PCEs) require an accurate and timely Traffic Engineering
   Database (TED).  Traditionally this TED has been obtained from a link
   state (LS) routing protocol supporting traffic engineering
   extensions.

   This document extends the Path Computation Element Communication
   Protocol (PCEP) with Link-State and TE Information.

Status of This Memo

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

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on March 24, 2016.

Copyright Notice

   Copyright (c) 2015 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) in effect on the date of
   publication of this document.  Please review these documents



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   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   4
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Applicability . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Requirements for PCEP extension . . . . . . . . . . . . . . .   5
   5.  New Functions to distribute link-state (and TE) via PCEP  . .   5
   6.  Overview of Extension to PCEP . . . . . . . . . . . . . . . .   6
     6.1.  New Messages  . . . . . . . . . . . . . . . . . . . . . .   6
     6.2.  Capability Advertisement  . . . . . . . . . . . . . . . .   6
     6.3.  Initial Link-State (and TE) Synchronization . . . . . . .   7
       6.3.1.  Optimizations for LS Synchronization  . . . . . . . .   9
     6.4.  LS Report . . . . . . . . . . . . . . . . . . . . . . . .  10
   7.  Transport . . . . . . . . . . . . . . . . . . . . . . . . . .  10
   8.  PCEP Messages . . . . . . . . . . . . . . . . . . . . . . . .  10
     8.1.  LS Report Message . . . . . . . . . . . . . . . . . . . .  10
     8.2.  The PCErr Message . . . . . . . . . . . . . . . . . . . .  11
   9.  Objects and TLV . . . . . . . . . . . . . . . . . . . . . . .  11
     9.1.  Open Object . . . . . . . . . . . . . . . . . . . . . . .  12
       9.1.1.  LS Capability TLV . . . . . . . . . . . . . . . . . .  12
     9.2.  LS Object . . . . . . . . . . . . . . . . . . . . . . . .  12
       9.2.1.  Routing Universe TLV  . . . . . . . . . . . . . . . .  14
       9.2.2.  Local Node Descriptors TLV  . . . . . . . . . . . . .  15
       9.2.3.  Remote Node Descriptors TLV . . . . . . . . . . . . .  16
       9.2.4.  Node Descriptors Sub-TLVs . . . . . . . . . . . . . .  16
       9.2.5.  Multi-Topology ID TLV . . . . . . . . . . . . . . . .  17
       9.2.6.  Link Descriptors TLV  . . . . . . . . . . . . . . . .  17
       9.2.7.  Prefix Descriptors  . . . . . . . . . . . . . . . . .  19
       9.2.8.  PCEP-LS Attributes TLV  . . . . . . . . . . . . . . .  19
         9.2.8.1.  Node Attributes TLV . . . . . . . . . . . . . . .  19
         9.2.8.2.  Link Attributes TLV . . . . . . . . . . . . . . .  20
         9.2.8.3.  Prefix Attributes TLV . . . . . . . . . . . . . .  22
   10. Other Considerations  . . . . . . . . . . . . . . . . . . . .  23
     10.1.  Inter-AS Links . . . . . . . . . . . . . . . . . . . . .  23
   11. Security Considerations . . . . . . . . . . . . . . . . . . .  23
   12. Manageability Considerations  . . . . . . . . . . . . . . . .  23
     12.1.  Control of Function and Policy . . . . . . . . . . . . .  23
     12.2.  Information and Data Models  . . . . . . . . . . . . . .  23
     12.3.  Liveness Detection and Monitoring  . . . . . . . . . . .  23
     12.4.  Verify Correct Operations  . . . . . . . . . . . . . . .  23
     12.5.  Requirements On Other Protocols  . . . . . . . . . . . .  24



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     12.6.  Impact On Network Operations . . . . . . . . . . . . . .  24
   13. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  24
   14. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . . .  24
   15. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  26
   16. References  . . . . . . . . . . . . . . . . . . . . . . . . .  26
     16.1.  Normative References . . . . . . . . . . . . . . . . . .  27
     16.2.  Informative References . . . . . . . . . . . . . . . . .  27
   Appendix A.  Contributor Addresses  . . . . . . . . . . . . . . .  29
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  29

1.  Introduction

   In Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS),
   a Traffic Engineering Database (TED) is used in computing paths for
   connection oriented packet services and for circuits.  The TED
   contains all relevant information that a Path Computation Element
   (PCE) needs to perform its computations.  It is important that the
   TED be complete and accurate each time, the PCE performs a path
   computation.

   In MPLS and GMPLS, interior gateway routing protocols (IGPs) have
   been used to create and maintain a copy of the TED at each node
   running the IGP.  One of the benefits of the PCE architecture
   [RFC4655] is the use of computationally more sophisticated path
   computation algorithms and the realization that these may need
   enhanced processing power not necessarily available at each node
   participating in an IGP.

   Section 4.3 of [RFC4655] describes the potential load of the TED on a
   network node and proposes an architecture where the TED is maintained
   by the PCE rather than the network nodes.  However, it does not
   describe how a PCE would obtain the information needed to populate
   its TED.  PCE may construct its TED by participating in the IGP
   ([RFC3630]  and [RFC5305]  for MPLS-TE; [RFC4203]  and [RFC5307] for
   GMPLS).  An alternative is offered by BGP-LS
   [I-D.ietf-idr-ls-distribution] .

   [I-D.lee-pce-transporting-te-data] proposes some other approaches for
   creating and maintaining the TED directly on a PCE as an alternative
   to IGPs and BGP flooding and investigate the impact from the PCE,
   routing protocol, and node perspectives.

   [RFC5440] describes the specifications for the Path Computation
   Element Communication Protocol (PCEP).  PCEP specifies the
   communication between a Path Computation Client (PCC) and a Path
   Computation Element (PCE), or between two PCEs based on the PCE
   architecture [RFC4655].




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   This document describes a mechanism by which Link State and TE
   information can be collected from networks and shared with PCE using
   the PCEP itself.  This is achieved using a new PCEP message format.
   The mechanism is applicable to physical and virtual links as well as
   further subjected to various policies.

   A router maintains one or more databases for storing link-state and
   TE information about nodes and links in any given area.  Link
   attributes stored in these databases include: local/remote IP
   addresses, local/ remote interface identifiers, link metric and TE
   metric, link bandwidth, reservable bandwidth, per CoS class
   reservation state, preemption and Shared Risk Link Groups (SRLG).
   The router's PCEP process can retrieve topology from these databases
   and distribute it to a PCE, either directly or via another PCEP
   Speaker, using the encoding specified in this document.

1.1.  Requirements Language

   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 [RFC2119].

2.  Terminology

   The terminology is as per [RFC4655] and [RFC5440].

3.  Applicability

   As per [I-D.lee-pce-transporting-te-data], the mechanism specified in
   this draft is applicable to:

   o  Where there is no IGP or BGP-LS running at the PCE to learn link-
      state and TE information.

   o  Where there is IGP or BGP-LS running but with a need for a faster
      TE and link-state population and convergence at the PCE.

      *  A PCE may receive partial information (say basic TE, link-
         state) from IGP and other information (optical and impairment)
         from PCEP.

      *  A PCE may receive full information from both existing mechanism
         (IGP or BGP) and PCEP.

   A PCC may further choose to send only local information or both local
   and remote learned information.





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   How a PCE manages the link-state (and TE) information is
   implementation specific and thus out of scope of this document.

4.  Requirements for PCEP extension

   Following key requirements associated with link-state (and TE)
   distribution are identified for PCEP:

   1.  The PCEP speaker supporting this draft MUST be a mechanism to
       advertise the Link-State (and TE) distribution capability.

   2.  PCC supporting this draft MUST have the capability to report the
       link-state (and TE) information to the PCE.  This includes self
       originated information and remote information learned via routing
       protocols.  PCC MUST be capable to do the initial bulk sync at
       the time of session initialization as well as changes after.

   3.  A PCE MAY learn link-state (and TE) from PCEP as well as from
       existing mechanism like IGP/BGP-LS.  PCEP extension MUST have a
       mechanism to link the information learned via other means.  There
       MUST NOT be any changes to the existing link-state (and TE)
       population mechanism via IGP/BGP-LS.  PCEP extension SHOULD keep
       the properties in a protocol (IGP or BGP-LS) neutral way, such
       that an implementation maynot need to know about any OSPF or IS-
       IS or BGP protocol specifics.

   4.  It SHOULD be possible to encode only the changes in link-state
       (and TE) properties (after the initial sync) in PCEP messages.

   5.  The same mechanism should be used for both MPLS TE as well as
       GMPLS, optical and impairment aware properties.

   6.  The extension in this draft SHOULD be extensible to support
       various architecture options listed in
       [I-D.lee-pce-transporting-te-data].

5.  New Functions to distribute link-state (and TE) via PCEP

   Several new functions are required in PCEP to support distribution of
   link-state (and TE) information.  A function can be initiated either
   from a PCC towards a PCE (C-E) or from a PCE towards a PCC (E-C).
   The new functions are:

   o  Capability advertisement (E-C,C-E): both the PCC and the PCE must
      announce during PCEP session establishment that they support PCEP
      extensions for distribution of link-state (and TE) information
      defined in this document.




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   o  Link-State (and TE) synchronization (C-E): after the session
      between the PCC and a PCE is initialized, the PCE must learn Link-
      State (and TE) information before it can perform path
      computations.  In case of stateful PCE it is RECOMENDED that this
      operation be done before LSP state synchronization.

   o  Link-State (and TE) Report (C-E): a PCC sends a LS report to a PCE
      whenever the Link-State (and TE) information changes.

6.  Overview of Extension to PCEP

6.1.  New Messages

   In this document, we define a new PCEP messages called LS Report
   (LSRpt), a PCEP message sent by a PCC to a PCE to report link-state
   (and TE) information.  Each LS Report in a LSRpt message can contain
   the node or link properties.  An unique PCEP specific LS identifier
   (LS-ID) is also carried in the message to identify a node or link and
   that remains constant for the lifetime of a PCEP session.  This
   identifier on its own is sufficient when no IGP or BGP-LS running in
   the network for PCE to learn link-state (and TE) information.  Incase
   PCE learns some information from PCEP and some from the existing
   mechanism, the PCC SHOULD include the mapping of IGP or BGP-LS
   identifier to map the information populated via PCEP with IGP/BGP-LS.
   See Section 8.1 for details.

6.2.  Capability Advertisement

   During PCEP Initialization Phase, PCEP Speakers (PCE or PCC)
   advertise their support of LS (and TE) distribution via PCEP
   extensions.  A PCEP Speaker includes the "LS Capability" TLV,
   described in Section 9.1.1, in the OPEN Object to advertise its
   support for PCEP-LS extensions.  The presence of the LS Capability
   TLV in PCC's OPEN Object indicates that the PCC is willing to send LS
   Reports whenever local link-state (and TE) information changes.  The
   presence of the LS Capability TLV in PCE's OPEN message indicates
   that the PCE is interested in receiving LS Reports whenever local
   link-state (and TE) information changes.

   The PCEP protocol extensions for LS (and TE) distribution MUST NOT be
   used if one or both PCEP Speakers have not included the LS Capability
   TLV in their respective OPEN message.  If the PCE that supports the
   extensions of this draft but did not advertise this capability, then
   upon receipt of a LSRpt message from the PCC, it SHOULD generate a
   PCErr with error-type 19 (Invalid Operation), error-value TBD1
   (Attempted LS Report if LS capability was not advertised) and it will
   terminate the PCEP session.




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   The LS reports sent by PCC MAY carry the remote link-state (and TE)
   information learned via existing means like IGP and BGP-LS only if
   both PCEP Speakers set the R (remote) Flag in the "LS Capability" TLV
   to 'Remote Allowed (R Flag = 1)'.  If this is not the case and LS
   reports carry remote link-state (and TE) information, then a PCErr
   with error-type 19 (Invalid Operation) and error-value TBD1
   (Attempted LS Report if LS remote capability was not advertised) and
   it will terminate the PCEP session.

6.3.  Initial Link-State (and TE) Synchronization

   The purpose of LS Synchronization is to provide a checkpoint-in- time
   state replica of a PCC's link-state (and TE) data base in a PCE.
   State Synchronization is performed immediately after the
   Initialization phase (see [RFC5440]]).  In case of stateful PCE
   ([I-D.ietf-pce-stateful-pce]) it is RECOMENDED that the LS
   synchronization should be done before LSP state synchronization.

   During LS Synchronization, a PCC first takes a snapshot of the state
   of its database, then sends the snapshot to a PCE in a sequence of LS
   Reports.  Each LS Report sent during LS Synchronization has the SYNC
   Flag in the LS Object set to 1.  The end of synchronization marker is
   a LSRpt message with the SYNC Flag set to 0 for an LS Object with LS-
   ID equal to the reserved value 0.  If the PCC has no link-state to
   synchronize, it will only send the end of synchronization marker.

   Either the PCE or the PCC MAY terminate the session using the PCEP
   session termination procedures during the synchronization phase.  If
   the session is terminated, the PCE MUST clean up state it received
   from this PCC.  The session re-establishment MUST be re-attempted per
   the procedures defined in [RFC5440], including use of a back-off
   timer.

   If the PCC encounters a problem which prevents it from completing the
   LS syncronization, it MUST send a PCErr message with error-type TBD2
   (LS Synchronization Error) and error-value 5 (indicating an internal
   PCC error) to the PCE and terminate the session.

   The PCE does not send positive acknowledgements for properly received
   LS synchronization messages.  It MUST respond with a PCErr message
   with error-type TBD2 (LS Synchronization Error) and error-value 1
   (indicating an error in processing the LSRpt) if it encounters a
   problem with the LS Report it received from the PCC and it MUST
   terminate the session.

   The LS reports can carry local as well as remote link-state (and TE)
   information depending on the R flag in LS capability TLV.




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   The successful LS Synchronization sequences is shown in Figure 1.


         +-+-+                    +-+-+
         |PCC|                    |PCE|
         +-+-+                    +-+-+
           |                        |
           |-----LSRpt, SYNC=1----->| (Sync start)
           |                        |
           |-----LSRpt, SYNC=1----->|
           |            .           |
           |            .           |
           |            .           |
           |-----LSRpt, SYNC=1----->|
           |            .           |
           |            .           |
           |            .           |
           |                        |
           |-----LSRpt, SYNC=0----->| (End of sync marker
           |                        |  LS Report
           |                        |  for LS-ID=0)
           |                        | (Sync done)


                  Figure 1: Successful LS synchronization

   The sequence where the PCE fails during the LS Synchronization phase
   is shown in Figure 2.























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         +-+-+                    +-+-+
         |PCC|                    |PCE|
         +-+-+                    +-+-+
           |                        |
           |-----LSRpt, SYNC=1----->|
           |                        |
           |-----LSRpt, SYNC=1----->|
           |            .           |
           |            .           |
           |            .           |
           |-----LSRpt, SYNC=1----->|
           |                        |
           |---LSRpt,SYNC=1         |
           |         \    ,-PCErr---|
           |          \  /          |
           |           \/           |
           |           /\           |
           |          /   `-------->| (Ignored)
           |<--------`              |


             Figure 2: Failed LS synchronization (PCE failure)

   The sequence where the PCC fails during the LS Synchronization phase
   is shown in Figure 3.

         +-+-+                    +-+-+
         |PCC|                    |PCE|
         +-+-+                    +-+-+
           |                        |
           |-----LSRpt, SYNC=1----->|
           |                        |
           |-----LSRpt, SYNC=1----->|
           |            .           |
           |            .           |
           |            .           |
           |-------- PCErr--------->|
           |                        |


             Figure 3: Failed LS synchronization (PCC failure)

6.3.1.  Optimizations for LS Synchronization

   A seperate document is created for this.






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6.4.  LS Report

   The PCC MUST report any changes in the link-state (and TE)
   information to the PCE by sending a LS Report carried on a LSRpt
   message to the PCE.  Each node and Link would be uniquely identified
   by a PCEP LS identifier (LS-ID).  The LS reports may carry local as
   well as remote link-state (and TE) information depending on the R
   flag in LS capability TLV.  In case R flag is set, It MAY also
   include the mapping of IGP or BGP-LS identifier to map the
   information populated via PCEP with IGP/BGP-LS.

   More details about LSRpt message are in Section 8.1.

7.  Transport

   A permanent PCEP session MUST be established between a PCE and PCC
   supporting link-state (and TE) distribution via PCEP.  In the case of
   session failure, session re-establishment MUST be re-attempted per
   the procedures defined in [RFC5440].

8.  PCEP Messages

   As defined in [RFC5440], a PCEP message consists of a common header
   followed by a variable-length body made of a set of objects that can
   be either mandatory or optional.  An object is said to be mandatory
   in a PCEP message when the object must be included for the message to
   be considered valid.  For each PCEP message type, a set of rules is
   defined that specify the set of objects that the message can carry.
   An implementation MUST form the PCEP messages using the object
   ordering specified in this document.

8.1.  LS Report Message

   A PCEP LS Report message (also referred to as LSRpt message) is a
   PCEP message sent by a PCC to a PCE to report the link-state (and TE)
   information.  A LSRpt message can carry more than one LS Reports.
   The Message-Type field of the PCEP common header for the LSRpt
   message is set to [TBD3].

   The format of the LSRpt message is as follows:

   <LSRpt Message> ::= <Common Header>
                       <ls-report-list>
   Where:

   <ls-report-list> ::= <LS>[<ls-report-list>]





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   The LS object is a mandatory object which carries LS information of a
   node or a link.  Each LS object has an unique LS-ID as described in
   Section 9.2.  If the LS object is missing, the receiving PCE MUST
   send a PCErr message with Error-type=6 (Mandatory Object missing) and
   Error-value=[TBD4] (LS object missing).

   A PCE may choose to implement a limit on the LS information a single
   PCC can populate.  If a LSRpt is received that causes the PCE to
   exceed this limit, it MUST send a PCErr message with error-type 19
   (invalid operation) and error-value 4 (indicating resource limit
   exceeded) in response to the LSRpt message triggering this condition
   and SHOULD terminate the session.

8.2.  The PCErr Message

   If a PCEP speaker has advertised the LS capability on the PCEP
   session, the PCErr message MAY include the LS object.  If the error
   reported is the result of an LS report, then the LS-ID number MUST be
   the one from the LSRpt that triggered the error.

   The format of a PCErr message from [RFC5440] is extended as follows:

   The format of the PCErr message is as follows:

   <PCErr Message> ::= <Common Header>
                     ( <error-obj-list> [<Open>] ) | <error>
                     [<error-list>]

   <error-obj-list>::=<PCEP-ERROR>[<error-obj-list>]

   <error>::=[<request-id-list> | <ls-id-list>]
              <error-obj-list>

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

   <ls-id-list>::=<LS>[<ls-id-list>]

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

9.  Objects and TLV

   The PCEP objects defined in this document are compliant with the PCEP
   object format defined in [RFC5440].  The P flag and the I flag of the
   PCEP objects defined in this document MUST always be set to 0 on
   transmission and MUST be ignored on receipt since these flags are
   exclusively related to path computation requests.





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9.1.  Open Object

   This document defines a new optional TLV for use in the OPEN Object.

9.1.1.  LS Capability TLV

   The LS-CAPABILITY TLV is an optional TLV for use in the OPEN Object
   for link-state (and TE) distribution via PCEP capability
   advertisement.  Its format is shown in the following figure:

    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=[TBD5]     |            Length=4           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                             Flags                           |R|
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The type of the TLV is [TBD5] and it has a fixed length of 4 octets.

   The value comprises a single field - Flags (32 bits):

   o  R (remote - 1 bit): if set to 1 by a PCC, the R Flag indicates
      that the PCC allows reporting of remote LS information learned via
      other means like IGP and BGP-LS; if set to 1 by a PCE, the R Flag
      indicates that the PCE is capable of receiving remote LS
      information (from the PCC point of view).  The R Flag must be
      advertised by both a PCC and a PCE for LSRpt messages to report
      remote as well as local LS information on a PCEP session.  The
      TLVs related to IGP/BGP-LS identifier MUST be encoded when both
      PCEP speakers have the R Flag set.

   Unassigned bits are considered reserved.  They MUST be set to 0 on
   transmission and MUST be ignored on receipt.

   Advertisement of the LS capability implies support of local link-
   state (and TE) distribution, as well as the objects, TLVs and
   procedures defined in this document.

9.2.  LS Object

   The LS (link-state) object MUST be carried within LSRpt messages and
   MAY be carried within PCErr messages.  The LS object contains a set
   of fields used to specify the target node or link.  It also contains
   a flag indicating to a PCE that the LS synchronization is in
   progress.  The TLVs used with the LS object correlate with the IGP/
   BGP-LS encodings.




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   LS Object-Class is [TBD6].

   Four Object-Type values are defined for the LS object so far:

   o  LS Node: LS Object-Type is 1.

   o  LS Link: LS Object-Type is 2.

   o  LS IPv4 Topology Prefix: LS Object-Type is 3.

   o  LS IPv6 Topology Prefix: LS Object-Type is 4.

   The format of all types of LS object 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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  Protocol-ID  |          Flag                             |R|S|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                          LS-ID                                |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     //                         TLVs                                //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   Protocol-ID (8-bit): The field provide the source information.
   Incase PCC only provides local information (R flag is not set), it
   MUST use Protocol-ID as Direct.  The following values are defined
   (same as [I-D.ietf-idr-ls-distribution]):

            +-------------+----------------------------------+
            | Protocol-ID | Source protocol                  |
            +-------------+----------------------------------+
            |      1      | IS-IS Level 1                    |
            |      2      | IS-IS Level 2                    |
            |      3      | OSPFv2                           |
            |      4      | Direct                           |
            |      5      | Static configuration             |
            |      6      | OSPFv3                           |
            +-------------+----------------------------------+

   Flags (32-bit):

   o  S (SYNC - 1 bit): the S Flag MUST be set to 1 on each LSRpt sent
      from a PCC during LS Synchronization.  The S Flag MUST be set to 0
      in other LSRpt messages sent from the PCC.




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   o  R (Remove - 1 bit): On LSRpt messages the R Flag indicates that
      the node/link/prefix has been removed from the PCC and the PCE
      SHOULD remove from its database.  Upon receiving an LS Report with
      the R Flag set to 1, the PCE SHOULD remove all state for the
      node/link/prefix identified by the LS Identifiers from its
      database.

   LS-ID(64-bit): A PCEP-specific identifier for the node or link or
   prefix information.  A PCC creates an unique LS-ID for each
   node/link/prefix that is constant for the lifetime of a PCEP session.
   The PCC will advertise the same LS-ID on all PCEP sessions it
   maintains at a given times.  All subsequent PCEP messages then
   address the node/link/prefix by the LS-ID.  The values of 0 and
   0xFFFFFFFFFFFFFFFF are reserved.

   Unassigned bits are considered reserved.  They MUST be set to 0 on
   transmission and MUST be ignored on receipt.

   TLVs that may be included in the LS Object are described in the
   following sections.

9.2.1.  Routing Universe TLV

   In case of remote link-state (and TE) population when existing IGP/
   BGP-LS are also used, OSPF and IS-IS may run multiple routing
   protocol instances over the same link as described in
   [I-D.ietf-idr-ls-distribution].  See [RFC6822] and [RFC6549] for more
   information.  These instances define independent "routing universes".
   The 64-Bit 'Identifier' field is used to identify the "routing
   universe" where the LS object belongs.  The LS objects representing
   IGP objects (nodes or links or prefix) from the same routing universe
   MUST have the same 'Identifier' value; LS objects with different
   'Identifier' values MUST be considered to be from different routing
   universes.

   The format of the ROUTING-UNIVERSE TLV is shown in the following
   figure:

      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=[TBD7]         |           Length=8            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Identifier                          |
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+





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   Below table lists the 'Identifier' values that are defined as well-
   known in this draft (same as [I-D.ietf-idr-ls-distribution]).

            +------------+-----------------------------------+
            | Identifier | Routing Universe                  |
            +------------+-----------------------------------+
            |     0      | Default Layer 3 Routing topology  |
            |    1-31    | Reserved                          |
            +------------+-----------------------------------+

   If this TLV is not present the default value 0 is assumed.

9.2.2.  Local Node Descriptors TLV

   As described in [I-D.ietf-idr-ls-distribution], each link is anchored
   by a pair of Router-IDs that are used by the underlying IGP, namely,
   48 Bit ISO System-ID for IS-IS and 32 bit Router-ID for OSPFv2 and
   OSPFv3.  Incase of additional auxiliary Router-IDs used for TE, these
   MUST also be included in the link attribute TLV (see
   Section 9.2.8.2).

   It is desirable that the Router-ID assignments inside the Node
   Descriptor are globally unique.  Some considerations for globally
   unique Node/Link/Prefix identifiers are described in
   [I-D.ietf-idr-ls-distribution].

   The Local Node Descriptors TLV contains Node Descriptors for the node
   anchoring the local end of the link.  This TLV MUST be included in
   the LS Report when during a given PCEP session a node/link/prefix is
   first reported to a PCE.  A PCC sends to a PCE the first LS Report
   either during State Synchronization, or when a new node/link/prefix
   is learned at the PCC.  The value contains one or more Node
   Descriptor Sub-TLVs, which allows specification of a flexible key for
   any given node/link/prefix information such that global uniqueness of
   the node/link/prefix is ensured.

      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=[TBD8]         |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //              Node Descriptor Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The value contains one or more Node Descriptor Sub-TLVs defined in
   Section 9.2.4.



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9.2.3.  Remote Node Descriptors TLV

   The Remote Node Descriptors contains Node Descriptors for the node
   anchoring the remote end of the link.  This TLV MUST be included in
   the LS Report when during a given PCEP session a link is first
   reported to a PCE.  A PCC sends to a PCE the first LS Report either
   during State Synchronization, or when a new link is learned at the
   PCC.  The length of this TLV is variable.  The value contains one or
   more Node Descriptor Sub-TLVs defined in Section 9.2.4.

      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=[TBD9]         |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //              Node Descriptor Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

9.2.4.  Node Descriptors Sub-TLVs

   The Node Descriptor Sub-TLV type Type and lengths are listed in the
   following table:

           +--------------------+-------------------+----------+
           | Sub-TLV            | Description       |   Length |
           +--------------------+-------------------+----------+
           |        TBD10       | Autonomous System |        4 |
           |        TBD11       | BGP-LS Identifier |        4 |
           |        TBD12       | OSPF Area-ID      |        4 |
           |        TBD13       | IGP Router-ID     | Variable |
           |        TBD44       | Multi-Topology-ID | Variable |
           +--------------------+-------------------+----------+

   The sub-TLV values in Node Descriptor TLVs are defined as follows
   (similar to [I-D.ietf-idr-ls-distribution]):

   o  Autonomous System: opaque value (32 Bit AS Number)

   o  BGP-LS Identifier: opaque value (32 Bit ID).  In conjunction with
      ASN, uniquely identifies the BGP-LS domain as described in
      [I-D.ietf-idr-ls-distribution].  This sub-TLV is present only if
      the node implements BGP-LS and the ID is set by the operator.

   o  OSPF Area ID: It is used to identify the 32 Bit area to which the
      LS object belongs.  Area Identifier allows the different LS
      objects of the same router to be discriminated.



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   o  IGP Router ID: opaque value.  Usage is described in
      [I-D.ietf-idr-ls-distribution] for IGP Router ID.  In case only
      local information is transported and PCE learns link-state (and
      TE) information only from PCEP, it contain the unique local TE
      IPv4 or IPv6 router ID.

   o  Multi-Topology-ID: Usage is described in
      [I-D.ietf-idr-ls-distribution] for MT-ID.

   o  There can be at most one instance of each sub-TLV type present in
      any Node Descriptor.

9.2.5.  Multi-Topology ID TLV

   The Multi-Topology ID (MT-ID) TLV carries one or more IS-IS or OSPF
   Multi-Topology IDs for a link, node or prefix.  The semantics of the
   IS-IS MT-ID are defined in Section 7.2 of [RFC5120].  The MT-ID TLV
   MAY be present in a Link Descriptor, a Prefix Descriptor, or in the
   attribute of a node (Node Attributes TLV) in LS object.

   The format and handling of the MT-ID TLV is as defined in
   [I-D.ietf-idr-ls-distribution].

   In a Link or Prefix Descriptor, only a single MT-ID TLV containing
   the MT-ID of the topology where the link or the prefix is reachable
   is allowed.  In case one wants to advertise multiple topologies for a
   given Link Descriptor or Prefix Descriptor, multiple reports need to
   be generated where each LS object contains an unique MT-ID.  In the
   attribute of a node (Node Attributes TLV) in LS object, one MT-ID TLV
   containing the array of MT-IDs of all topologies where the node is
   reachable is allowed.

9.2.6.  Link Descriptors TLV

   The Link Descriptors TLV contains Link Descriptors for each link.
   This TLV MUST be included in the LS Report when during a given PCEP
   session a link is first reported to a PCE.  A PCC sends to a PCE the
   first LS Report either during State Synchronization, or when a new
   link is learned at the PCC.  The length of this TLV is variable.  The
   value contains one or more Link Descriptor Sub-TLVs.

   The 'Link descriptor' TLVs uniquely identify a link among multiple
   parallel links between a pair of anchor routers similar to
   [I-D.ietf-idr-ls-distribution].







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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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           Type=[TBD14]        |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //              Link Descriptor Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Link Descriptor Sub-TLV type and lengths are listed in the
   following table:

   +-----------+---------------------+---------------+-----------------+
   |  Sub-TLV  | Description         |   IS-IS TLV   | Value defined   |
   |           |                     |    /Sub-TLV   | in:             |
   +-----------+---------------------+---------------+-----------------+
   |    TBD15  | Link Local/Remote   |      22/4     | [RFC5307]/1.1   |
   |           | Identifiers         |               |                 |
   |    TBD16  | IPv4 interface      |      22/6     | [RFC5305]/3.2   |
   |           | address             |               |                 |
   |    TBD17  | IPv4 neighbor       |      22/8     | [RFC5305]/3.3   |
   |           | address             |               |                 |
   |    TBD18  | IPv6 interface      |     22/12     | [RFC6119]/4.2   |
   |           | address             |               |                 |
   |    TBD19  | IPv6 neighbor       |     22/13     | [RFC6119]/4.3   |
   |           | address             |               |                 |
   |    TBD44  | Multi-Topology      |       -       | [I-D.ietf-idr-  |
   |           | identifier          |               | ls-distribution]|
   |           |                     |               | /3.2.1.5        |
   +-----------+---------------------+---------------+-----------------+

   The format and semantics of the 'value' fields in most 'Link
   Descriptor' sub-TLVs correspond to the format and semantics of value
   fields in IS-IS Extended IS Reachability sub-TLVs, defined in
   [RFC5305], [RFC5307] and [RFC6119].  Although the encodings for 'Link
   Descriptor' TLVs were originally defined for IS-IS, the TLVs can
   carry data sourced either by IS-IS or OSPF or direct.

   The information about a link present in the LSA/LSP originated by the
   local node of the link determines the set of sub-TLVs in the Link
   Descriptor of the link as described in
   [I-D.ietf-idr-ls-distribution].








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9.2.7.  Prefix Descriptors

   The 'Prefix Descriptor' field is a set of Type/Length/Value (TLV)
   triplets.  'Prefix Descriptor' TLVs uniquely identify an IPv4 or IPv6
   Prefix originated by a Node.  The following TLVs are valid as Prefix
   Descriptors in the IPv4/IPv6 Prefix-


   +--------------+-----------------------+----------+-----------------+
   |   TLV Code   | Description           |  Length  | Value defined   |
   |    Point     |                       |          | in:             |
   +--------------+-----------------------+----------+-----------------+
   |   TBD44      | Multi-Topology        | variable | [I-D.ietf-idr-  |
   |              | Identifier            |          | ls-distribution]|
   |              |                       |          | /3.2.1.5        |
   |   TBD45      | OSPF Route Type       |    1     | [I-D.ietf-idr-  |
   |              |                       |          | ls-distribution]|
   |              |                       |          | /3.2.3.1        |
   |   TBD46      | IP Reachability       | variable | [I-D.ietf-idr-  |
   |              | Information           |          | ls-distribution]|
   |              |                       |          | /3.2.3.2        |
   +--------------+-----------------------+----------+-----------------+

9.2.8.  PCEP-LS Attributes TLV

9.2.8.1.  Node Attributes TLV

   This is an optional attribute that is used to carry node attributes.
   The node attribute TLV may be encoded in the LS node Object.

      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=[TBD20]        |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //              Node Attributes Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The Node Attributes Sub-TLV type and lengths are listed in the
   following table:









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   +--------------+-----------------------+----------+-----------------+
   |   Sub TLV    | Description           |   Length | Value defined   |
   |              |                       |          | in:             |
   +--------------+-----------------------+----------+-----------------+
   |     TBD44    | Multi-Topology        | variable | [I-D.ietf-idr-  |
   |              | Identifier            |          | ls-distribution]|
   |              |                       |          | /3.2.1.5        |
   |     TBD21    | Node Flag Bits        |        1 | [I-D.ietf-idr-  |
   |              |                       |          | ls-distribution]|
   |              |                       |          | /3.3.1.1        |
   |     TBD22    | Opaque Node           | variable | [I-D.ietf-idr-  |
   |              | Properties            |          | ls-distribution]|
   |              |                       |          | /3.3.1.5        |
   |     TBD23    | Node Name             | variable | [I-D.ietf-idr-  |
   |              |                       |          | ls-distribution]|
   |              |                       |          | /3.3.1.3        |
   |     TBD24    | IS-IS Area Identifier | variable | [I-D.ietf-idr-  |
   |              |                       |          | ls-distribution]|
   |              |                       |          | /3.3.1.2        |
   |     TBD25    | IPv4 Router-ID of     |        4 | [RFC5305]/4.3   |
   |              | Local Node            |          |                 |
   |     TBD26    | IPv6 Router-ID of     |       16 | [RFC6119]/4.1   |
   |              | Local Node            |          |                 |
   +--------------+-----------------------+----------+-----------------+

9.2.8.2.  Link Attributes TLV

   Link attribute TLV may be encoded in the LS Link Object.  The format
   and semantics of the 'value' fields in some 'Link Attribute' sub-TLVs
   correspond to the format and semantics of value fields in IS-IS
   Extended IS Reachability sub-TLVs, defined in [RFC5305], [RFC5307]
   and [I-D.ietf-idr-ls-distribution].  Although the encodings for 'Link
   Attribute' TLVs were originally defined for IS-IS, the TLVs can carry
   data sourced either by IS-IS or OSPF or direct.

      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=[TBD27]        |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //              Link Attributes Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The following 'Link Attribute' sub-TLVs are are valid :





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   +-----------+---------------------+--------------+------------------+
   |  Sub-TLV  | Description         |  IS-IS TLV   | Defined in:      |
   |           |                     |   /Sub-TLV   |                  |
   |           |                     |  BGP-LS TLV  |                  |
   +-----------+---------------------+--------------+------------------+
   |    TBD25  | IPv4 Router-ID of   |   134/---    | [RFC5305]/4.3    |
   |           | Local Node          |              |                  |
   |    TBD26  | IPv6 Router-ID of   |   140/---    | [RFC6119]/4.1    |
   |           | Local Node          |              |                  |
   |    TBD30  | IPv4 Router-ID of   |   134/---    | [RFC5305]/4.3    |
   |           | Remote Node         |              |                  |
   |    TBD31  | IPv6 Router-ID of   |   140/---    | [RFC6119]/4.1    |
   |           | Remote Node         |              |                  |
   |    TBD32  | Link Local/Remote   |     22/4     | [RFC5307]/1.1    |
   |           | Identifiers         |              |                  |
   |    TBD33  | Administrative      |     22/3     | [RFC5305]/3.1    |
   |           | group (color)       |              |                  |
   |    TBD34  | Maximum link        |     22/9     | [RFC5305]/3.3    |
   |           | bandwidth           |              |                  |
   |    TBD35  | Max. reservable     |    22/10     | [RFC5305]/3.5    |
   |           | link bandwidth      |              |                  |
   |    TBD36  | Unreserved          |    22/11     | [RFC5305]/3.6    |
   |           | bandwidth           |              |                  |
   |    TBD37  | TE Default Metric   |    22/18     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.2.3         |
   |    TBD38  | Link Protection     |    22/20     | [RFC5307]/1.2    |
   |           | Type                |              |                  |
   |    TBD39  | MPLS Protocol Mask  |     1094     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.2.2         |
   |    TBD40  | IGP Metric          |     1095     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.2.4         |
   |    TBD41  | Shared Risk Link    |     1096     | [I-D.ietf-idr-   |
   |           | Group               |              | ls-distribution] |
   |           |                     |              | /3.3.2.5         |
   |    TBD42  | Opaque link         |     1097     | [I-D.ietf-idr-   |
   |           | attributes          |              | ls-distribution] |
   |           |                     |              | /3.3.2.6         |
   |    TBD43  | Link Name attribute |     1098     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.2.7         |
   +-----------+---------------------+--------------+------------------+







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9.2.8.3.  Prefix Attributes TLV

   Prefix attribute TLV may be encoded in the LS Prefix Object.
   Prefixes are learned from the IGP (IS-IS or OSPF) or BGP topology
   with a set of IGP attributes (such as metric, route tags, etc.).
   This section describes the different attributes related to the IPv4/
   IPv6 prefixes.  Prefix Attributes TLVs SHOULD be encoded in the LS
   Prefix Object.

      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=[TBD53]        |             Length            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                                                               |
     //            Prefix Attributes Sub-TLVs (variable)            //
     |                                                               |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The following 'Link Attribute' sub-TLVs are are valid :

   +-----------+---------------------+--------------+------------------+
   |  Sub-TLV  | Description         |  BGP-LS TLV  | Defined in:      |
   +-----------+---------------------+--------------+------------------+
   |    TBD47  | IGP Flags           |     1152     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.3.1         |
   |    TBD48  | Route Tag           |     1153     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.3.2         |
   |    TBD49  | Extended Tag        |     1154     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.3.3         |
   |    TBD50  | Prefix Metric       |     1155     | [I-D.ietf-idr-   |
   |           |                     |              | ls-distribution] |
   |           |                     |              | /3.3.3.4         |
   |    TBD51  | OSPF Forwarding     |     1156     | [I-D.ietf-idr-   |
   |           | Address             |              | ls-distribution] |
   |           |                     |              | /3.3.3.5         |
   |    TBD52  | Opaque Prefix       |     1157     | [I-D.ietf-idr-   |
   |           | Attribute           |              | ls-distribution] |
   |           |                     |              | /3.3.3.6         |
   +-----------+---------------------+--------------+------------------+








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10.  Other Considerations

10.1.  Inter-AS Links

   The main source of LS (and TE) information is the IGP, which is not
   active on inter-AS links.  In some cases, the IGP may have
   information of inter-AS links ([RFC5392], [RFC5316]).  In other
   cases, an implementation SHOULD provide a means to inject inter-AS
   links into PCEP.  The exact mechanism used to provision the inter-AS
   links is outside the scope of this document.

11.  Security Considerations

   This document extends PCEP for LS (and TE) distribution including a
   new LSRpt message with new object and TLVs.  Procedures and protocol
   extensions defined in this document do not effect the overall PCEP
   security model.  See [RFC5440], [I-D.ietf-pce-pceps].  Tampering with
   the LSRpt message may have an effect on path computations at PCE.  It
   also provides adversaries an opportunity to eavesdrop and learn
   sensitive information and plan sophisticated attacks on the network
   infrastructure.  The PCE implementation SHOULD provide mechanisms to
   prevent strains created by network flaps and amount of LS (and TE)
   information.  Thus it is suggested that any mechanism used for
   securing the transmission of other PCEP message be applied here as
   well.  As a general precaution, it is RECOMMENDED that these PCEP
   extensions only be activated on authenticated and encrypted sessions
   belonging to the same administrative authority.

12.  Manageability Considerations

12.1.  Control of Function and Policy

   TBD.

12.2.  Information and Data Models

   TBD.

12.3.  Liveness Detection and Monitoring

   TBD.

12.4.  Verify Correct Operations

   TBD.






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12.5.  Requirements On Other Protocols

   TBD.

12.6.  Impact On Network Operations

   TBD.

13.  IANA Considerations



14.  TLV/Sub-TLV Code Points Summary

   This section contains the global table of all TLVs/Sub-TLVs in LS
   object defined in this document.

   +-----------+---------------------+---------------+-----------------+
   |  Sub-TLV  | Description         |     Ref TLV   | Value defined   |
   |           |                     |    /Sub-TLV   | in:             |
   +-----------+---------------------+---------------+-----------------+
   |    TBD7   | Routing Universe    |       --      | Sec 9.2.1       |
   |    TBD8   | Local Node          |      256      | [I-D.ietf-idr-  |
   |           | Descriptors         |               | ls-distribution]|
   |           |                     |               | /3.2.1.2        |
   |    TBD9   | Remote Node         |      257      | [I-D.ietf-idr-  |
   |           | Descriptors         |               | ls-distribution]|
   |           |                     |               | /3.2.1.3        |
   |    TBD10  | Autonomous System   |      512      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.1.4        |
   |    TBD11  | BGP-LS Identifier   |      513      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.1.4        |
   |    TBD12  | OSPF Area-ID        |      514      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.1.4        |
   |    TBD13  | IGP Router-ID       |      515      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.1.4        |
   |    TBD44  | Multi-Topology-ID   |      263      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.1.5        |
   |    TBD14  | Link Descriptors    |      --       | Sec 9.2.6       |
   |    TBD15  | Link Local/Remote   |      22/4     | [RFC5307]/1.1   |
   |           | Identifiers         |               |                 |
   |    TBD16  | IPv4 interface      |      22/6     | [RFC5305]/3.2   |
   |           | address             |               |                 |



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   |    TBD17  | IPv4 neighbor       |      22/8     | [RFC5305]/3.3   |
   |           | address             |               |                 |
   |    TBD18  | IPv6 interface      |     22/12     | [RFC6119]/4.2   |
   |           | address             |               |                 |
   |    TBD19  | IPv6 neighbor       |     22/13     | [RFC6119]/4.3   |
   |           | address             |               |                 |
   |    TBD45  | OSPF Route Type     |      264      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.2.3.1        |
   |    TBD46  | IP Reachability     |      265      | [I-D.ietf-idr-  |
   |           | Information         |               | ls-distribution]|
   |           |                     |               | /3.2.3.2        |
   |    TBD20  | Node Attributes     |      --       | Sec 9.2.8.1     |
   |    TBD21  | Node Flag Bits      |      1024     | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.1.1        |
   |    TBD22  | Opaque Node         |      1025     | [I-D.ietf-idr-  |
   |           | Properties          |               | ls-distribution]|
   |           |                     |               | /3.3.1.5        |
   |    TBD23  | Node Name           |      1026     | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.1.3        |
   |    TBD24  | IS-IS Area          |      1027     | [I-D.ietf-idr-  |
   |           | Identifier          |               | ls-distribution]|
   |           |                     |               | /3.3.1.2        |
   |    TBD25  | IPv4 Router-ID of   |      134/--   | [RFC5305]/4.3   |
   |           | Local Node          |               |                 |
   |    TBD26  | IPv6 Router-ID of   |      140/--   | [RFC6119]/4.1   |
   |           | Local Node          |               |                 |
   |    TBD27  | Link Attributes     |      --       | Sec 9.2.8.2     |
   |    TBD30  | IPv4 Router-ID of   |      134/--   | [RFC5305]/4.3   |
   |           | Remote Node         |               |                 |
   |    TBD31  | IPv6 Router-ID of   |      140/--   | [RFC6119]/4.1   |
   |           | Remote Node         |               |                 |
   |    TBD32  | Link Local/Remote   |     22/4      | [RFC5307]/1.1   |
   |           | Identifiers         |               |                 |
   |    TBD33  | Administrative      |     22/3      | [RFC5305]/3.1   |
   |           | group (color)       |               |                 |
   |    TBD34  | Maximum link        |     22/9      | [RFC5305]/3.3   |
   |           | bandwidth           |               |                 |
   |    TBD35  | Max. reservable     |    22/10      | [RFC5305]/3.5   |
   |           | link bandwidth      |               |                 |
   |    TBD36  | Unreserved          |    22/11      | [RFC5305]/3.6   |
   |           | bandwidth           |               |                 |
   |    TBD37  | TE Default Metric   |    22/18      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.2.3        |
   |    TBD38  | Link Protection     |    22/20      | [RFC5307]/1.2   |



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   |           | Type                |               |                 |
   |    TBD39  | MPLS Protocol Mask  |     1094      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.2.2        |
   |    TBD40  | IGP Metric          |     1095      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.2.4        |
   |    TBD41  | Shared Risk Link    |     1096      | [I-D.ietf-idr-  |
   |           | Group               |               | ls-distribution]|
   |           |                     |               | /3.3.2.5        |
   |    TBD42  | Opaque link         |     1097      | [I-D.ietf-idr-  |
   |           | attributes          |               | ls-distribution]|
   |           |                     |               | /3.3.2.6        |
   |    TBD43  | Link Name attribute |     1098      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.2.7        |
   |    TBD53  | Prefix Attributes   |      --       | Sec 9.2.8.3     |
   |    TBD47  | IGP Flags           |     1152      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.3.1        |
   |    TBD48  | Route Tag           |     1153      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.3.2        |
   |    TBD49  | Extended Tag        |     1154      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.3.3        |
   |    TBD50  | Prefix Metric       |     1155      | [I-D.ietf-idr-  |
   |           |                     |               | ls-distribution]|
   |           |                     |               | /3.3.3.4        |
   |    TBD51  | OSPF Forwarding     |     1156      | [I-D.ietf-idr-  |
   |           | Address             |               | ls-distribution]|
   |           |                     |               | /3.3.3.5        |
   |    TBD52  | Opaque Prefix       |     1157      | [I-D.ietf-idr-  |
   |           | Attribute           |               | ls-distribution]|
   |           |                     |               | /3.3.3.6        |
   +-----------+---------------------+---------------+-----------------+

15.  Acknowledgments

   This document borrows some of the structure and text from the
   [I-D.ietf-idr-ls-distribution].

16.  References








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16.1.  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,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC5305]  Li, T. and H. Smit, "IS-IS Extensions for Traffic
              Engineering", RFC 5305, DOI 10.17487/RFC5305, October
              2008, <http://www.rfc-editor.org/info/rfc5305>.

   [RFC5307]  Kompella, K., Ed. and Y. Rekhter, Ed., "IS-IS Extensions
              in Support of Generalized Multi-Protocol Label Switching
              (GMPLS)", RFC 5307, DOI 10.17487/RFC5307, October 2008,
              <http://www.rfc-editor.org/info/rfc5307>.

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

   [RFC6119]  Harrison, J., Berger, J., and M. Bartlett, "IPv6 Traffic
              Engineering in IS-IS", RFC 6119, DOI 10.17487/RFC6119,
              February 2011, <http://www.rfc-editor.org/info/rfc6119>.

   [I-D.ietf-idr-ls-distribution]
              Gredler, H., Medved, J., Previdi, S., Farrel, A., and S.
              Ray, "North-Bound Distribution of Link-State and TE
              Information using BGP", draft-ietf-idr-ls-distribution-11
              (work in progress), June 2015.

16.2.  Informative References

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

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

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




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   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120,
              DOI 10.17487/RFC5120, February 2008,
              <http://www.rfc-editor.org/info/rfc5120>.

   [RFC5316]  Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS
              Traffic Engineering", RFC 5316, DOI 10.17487/RFC5316,
              December 2008, <http://www.rfc-editor.org/info/rfc5316>.

   [RFC5392]  Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS
              Traffic Engineering", RFC 5392, DOI 10.17487/RFC5392,
              January 2009, <http://www.rfc-editor.org/info/rfc5392>.

   [RFC6549]  Lindem, A., Roy, A., and S. Mirtorabi, "OSPFv2 Multi-
              Instance Extensions", RFC 6549, DOI 10.17487/RFC6549,
              March 2012, <http://www.rfc-editor.org/info/rfc6549>.

   [RFC6822]  Previdi, S., Ed., Ginsberg, L., Shand, M., Roy, A., and D.
              Ward, "IS-IS Multi-Instance", RFC 6822,
              DOI 10.17487/RFC6822, December 2012,
              <http://www.rfc-editor.org/info/rfc6822>.

   [I-D.ietf-pce-stateful-pce]
              Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP
              Extensions for Stateful PCE", draft-ietf-pce-stateful-
              pce-11 (work in progress), April 2015.

   [I-D.ietf-pce-pceps]
              Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure
              Transport for PCEP", draft-ietf-pce-pceps-04 (work in
              progress), May 2015.

   [I-D.lee-pce-transporting-te-data]
              Lee, Y. and z. zhenghaomian@huawei.com, "PCE in Support of
              Transporting Traffic Engineering Data", draft-lee-pce-
              transporting-te-data-01 (work in progress), October 2014.












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Appendix A.  Contributor Addresses

                 Udayasree Palle
                 Huawei Technologies
                 Divyashree Techno Park, Whitefield
                 Bangalore, Karnataka  560037
                 India

                 EMail: udayasree.palle@huawei.com

                 Sergio Belotti
                 Alcatel-Lucent
                 Italy

                 EMail: sergio.belotti@alcatel-lucent.com


Authors' Addresses

   Dhruv Dhody
   Huawei Technologies
   Divyashree Techno Park, Whitefield
   Bangalore, Karnataka  560037
   India

   EMail: dhruv.ietf@gmail.com


   Young Lee
   Huawei Technologies
   5340 Legacy Drive, Building 3
   Plano, TX  75023
   USA

   EMail: leeyoung@huawei.com


   Daniele Ceccarelli
   Ericsson
   Torshamnsgatan,48
   Stockholm
   Sweden

   EMail: daniele.ceccarelli@ericsson.com







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