A YANG Data Model for Path Computation Element Communications Protocol (PCEP)
draft-pkd-pce-pcep-yang-06

PCE Working Group                                            R. Pobbathi
Internet-Draft                                                 V. KumarS
Intended status: Standards Track                           D. Dhody, Ed.
Expires: April 12, 2015                              Huawei Technologies
                                                             J. Hardwick
                                                              Metaswitch
                                                         October 9, 2014


 A YANG Data Model for Path Computation Element Communications Protocol
                                 (PCEP)
                       draft-pkd-pce-pcep-yang-00

Abstract

   This document defines a YANG data model for the management of Path
   Computation Element communications Protocol (PCEP) for communications
   between a Path Computation Client (PCC) and a Path Computation
   Element (PCE), or between two PCEs.  The data model includes
   configuration data and state data (status information and counters
   for the collection of statistics).

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 April 12, 2015.

Copyright Notice

   Copyright (c) 2014 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  Terminology and Notation  . . . . . . . . . . . . . . . . . .   3
     3.1.  Tree Diagrams . . . . . . . . . . . . . . . . . . . . . .   4
     3.2.  Prefixes in Data Node Names . . . . . . . . . . . . . . .   4
   4.  Objectives  . . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  The Design of PCEP Data Model . . . . . . . . . . . . . . . .   5
     5.1.  The Entity Lists  . . . . . . . . . . . . . . . . . . . .   8
     5.2.  The Peer Lists  . . . . . . . . . . . . . . . . . . . . .   9
     5.3.  The Session Lists . . . . . . . . . . . . . . . . . . . .   9
   6.  Advanced PCE Features . . . . . . . . . . . . . . . . . . . .  10
   7.  PCEP YANG Module  . . . . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  40
   9.  Manageability Considerations  . . . . . . . . . . . . . . . .  40
     9.1.  Control of Function and Policy  . . . . . . . . . . . . .  41
     9.2.  Information and Data Models . . . . . . . . . . . . . . .  41
     9.3.  Liveness Detection and Monitoring . . . . . . . . . . . .  41
     9.4.  Verify Correct Operations . . . . . . . . . . . . . . . .  41
     9.5.  Requirements On Other Protocols . . . . . . . . . . . . .  41
     9.6.  Impact On Network Operations  . . . . . . . . . . . . . .  41
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  41
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  41
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  41
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  41
     12.2.  Informative References . . . . . . . . . . . . . . . . .  41
   Appendix A.  Contributor Addresses  . . . . . . . . . . . . . . .  43

1.  Introduction

   The Path Computation Element (PCE) defined in [RFC4655] is an entity
   that is capable of computing a network path or route based on a
   network graph, and applying computational constraints.  A Path
   Computation Client (PCC) may make requests to a PCE for paths to be
   computed.

   PCEP is the communication protocol between a PCC and PCE and is
   defined in [RFC5440].  PCEP interactions include path computation
   requests and path computation replies as well as notifications of
   specific states related to the use of a PCE in the context of




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   Multiprotocol Label Switching (MPLS) and Generalized MPLS (GMPLS)
   Traffic Engineering (TE).

   This document defines a YANG [RFC6020] data model for the management
   of PCEP speakers.  It is important to establish a common data model
   for how PCEP speakers are identified, configured, and monitored.  The
   data model includes configuration data and state data (status
   information and counters for the collection of statistics).

   This document contains a specification of the base PCEP YANG module,
   "ietf-pcep" which provides the basic PCEP [RFC5440] data model.

   [Editor's Note: Further modules augmenting the data model with
   advanced features maybe handled in a future revision or a separate
   document.]

2.  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].

3.  Terminology and Notation

   This document uses the terminology defined in [RFC4655] and
   [RFC5440].  In particular, it uses the following acronyms.

   o  Path Computation Request message (PCReq).

   o  Path Computation Reply message (PCRep).

   o  Notification message (PCNtf).

   o  Error message (PCErr).

   o  Request Parameters object (RP).

   o  Synchronization Vector object (SVEC).

   o  Explicit Route object (ERO).

   This document also uses the following term defined in
   [I-D.ietf-pce-pcep-mib]:

   o  PCEP entity: a local PCEP speaker.

   o  PCEP peer: to refer to a remote PCEP speaker.




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   o  PCEP speaker: where it is not necessary to distinguish between
      local and remote.

3.1.  Tree Diagrams

   A graphical representation of the complete data tree is presented in
   Section 5.  The meaning of the symbols in these diagrams is as
   follows and as per [I-D.ietf-netmod-rfc6087bis]:

   o  Brackets "[" and "]" enclose list keys.

   o  Curly braces "{" and "}" contain names of optional features that
      make the corresponding node conditional.

   o  Abbreviations before data node names: "rw" means configuration
      (read-write), and "ro" state data (read-only).

   o  Symbols after data node names: "?" means an optional node and "*"
      denotes a "list" or "leaf-list".

   o  Parentheses enclose choice and case nodes, and case nodes are also
      marked with a colon (":").

   o  Ellipsis ("...") stands for contents of subtrees that are not
      shown.

3.2.  Prefixes in Data Node Names

   In this document, names of data nodes and other data model objects
   are often used without a prefix, as long as it is clear from the
   context in which YANG module each name is defined.  Otherwise, names
   are prefixed using the standard prefix associated with the
   corresponding YANG module, as shown in Table 1.

                 +--------+-----------------+-----------+
                 | Prefix | YANG module     | Reference |
                 +--------+-----------------+-----------+
                 | yang   | ietf-yang-types | [RFC6991] |
                 | inet   | ietf-inet-types | [RFC6991] |
                 +--------+-----------------+-----------+

             Table 1: Prefixes and corresponding YANG modules

4.  Objectives

   This section describes some of the design objectives for the model:





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   o  In case of existing implementations, it needs to map the data
      model defined in this document to their proprietary native data
      model.  To facilitate such mappings, the data model should be
      simple.

   o  The data model should be suitable for new implementations to use
      as is.

   o  Mapping to the PCEP MIB Module should be clear.

   o  The data model should allow for static configurations of peers.

   o  The data model should include read-only counters in order to
      gather statistics for sent and received PCEP messages, received
      messages with errors, and messages that could not be sent due to
      errors.

   o  It should be fairly straight forward to augment the base data
      model for advanced PCE features.

5.  The Design of PCEP Data Model

   The module, "ietf-pcep", defines the basic components of a PCE
   speaker.

   module ietf-pcep
    +--rw pcep
    |  +--rw entity* [addr-type addr]
    |     +--rw addr-type             inet:ip-version
    |     +--rw addr                  inet:ip-address
    |     +--rw enabled?              boolean
    |     +--rw role                  pcep-role
    |     +--rw description?          string
    |     +--rw connect-timer?        uint32
    |     +--rw connect-max-retry?    uint32
    |     +--rw init-backoff-timer?   uint32
    |     +--rw max-backoff-timer?    uint32
    |     +--rw open-wait-timer?      uint32
    |     +--rw keep-wait-timer?      uint32
    |     +--rw keep-alive-timer?     uint32
    |     +--rw dead-timer?           uint32
    |     +--rw allow-negotiation?    boolean
    |     +--rw max-keep-alive-timer? uint32
    |     +--rw max-dead-timer?       uint32
    |     +--rw min-keep-alive-timer? uint32
    |     +--rw min-dead-timer?       uint32
    |     +--rw sync-timer?           uint32
    |     +--rw request-timer?        uint32



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    |     +--rw max-sessions?         uint32
    |     +--rw max-unknown-reqs?     uint32
    |     +--rw max-unknown-msgs?     uint32
    |     +--rw peers
    |        +--rw peer* [addr-type addr]
    |           +--rw addr-type    inet:ip-version
    |           +--rw addr         inet:ip-address
    |           +--rw description? string
    +--ro pcep-state
       +--ro entity* [addr-type addr]
          +--ro index?                uint32
          +--ro addr-type             inet:ip-version
          +--ro addr                  inet:ip-address
          +--ro admin-status?         pcep-admin-status
          +--ro oper-status?          pcep-admin-status
          +--ro role?                 pcep-role
          +--ro connect-timer?        uint32
          +--ro connect-max-retry?    uint32
          +--ro init-backoff-timer?   uint32
          +--ro max-backoff-timer?    uint32
          +--ro open-wait-timer?      uint32
          +--ro keep-wait-timer?      uint32
          +--ro keep-alive-timer?     uint32
          +--ro dead-timer?           uint32
          +--ro allow-negotiation?    boolean
          +--ro max-keep-alive-timer? uint32
          +--ro max-dead-timer?       uint32
          +--ro min-keep-alive-timer? uint32
          +--ro min-dead-timer?       uint32
          +--ro sync-timer?           uint32
          +--ro request-timer?        uint32
          +--ro max-sessions?         uint32
          +--ro max-unknown-reqs?     uint32
          +--ro max-unknown-msgs?     uint32
          +--ro peers
             +--ro peer* [addr-type addr]
                +--ro addr-type                 inet:ip-version
                +--ro addr                      inet:ip-address
                +--ro role?                     pcep-role
                +--ro discontinuity-time?       yang:timestamp
                +--ro initiate-session?         boolean
                +--ro session-exists?           boolean
                +--ro num-sess-setup-ok?        yang:counter32
                +--ro num-sess-setup-fail?      yang:counter32
                +--ro session-up-time?          yang:timestamp
                +--ro session-fail-time?        yang:timestamp
                +--ro session-fail-up-time?     yang:timestamp
                +--ro avg-rsp-time?             uint32



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                +--ro lwm-rsp-time?             uint32
                +--ro hwm-rsp-time?             uint32
                +--ro num-pcreq-sent?           yang:counter32
                +--ro num-pcreq-rcvd?           yang:counter32
                +--ro num-pcrep-sent?           yang:counter32
                +--ro num-pcrep-rcvd?           yang:counter32
                +--ro num-pcerr-sent?           yang:counter32
                +--ro num-pcerr-rcvd?           yang:counter32
                +--ro num-pcntf-sent?           yang:counter32
                +--ro num-pcntf-rcvd?           yang:counter32
                +--ro num-keepalive-sent?       yang:counter32
                +--ro num-keepalive-rcvd?       yang:counter32
                +--ro num-unknown-rcvd?         yang:counter32
                +--ro num-corrupt-rcvd?         yang:counter32
                +--ro num-req-sent?             yang:counter32
                +--ro num-svec-sent?            yang:counter32
                +--ro num-svec-req-sent?        yang:counter32
                +--ro num-req-sent-pend-rep?    yang:counter32
                +--ro num-req-sent-ero-rcvd?    yang:counter32
                +--ro num-req-sent-nopath-rcvd? yang:counter32
                +--ro num-req-sent-cancel-rcvd? yang:counter32
                +--ro num-req-sent-error-rcvd?  yang:counter32
                +--ro num-req-sent-timeout?     yang:counter32
                +--ro num-req-sent-cancel-sent? yang:counter32
                +--ro num-req-rcvd?             yang:counter32
                +--ro num-svec-rcvd?            yang:counter32
                +--ro num-svec-req-rcvd?        yang:counter32
                +--ro num-req-rcvd-pend-rep?    yang:counter32
                +--ro num-req-rcvd-ero-sent?    yang:counter32
                +--ro num-req-rcvd-nopath-sent? yang:counter32
                +--ro num-req-rcvd-cancel-sent? yang:counter32
                +--ro num-req-rcvd-cancel-rcvd? yang:counter32
                +--ro num-rep-rcvd-unknown?     yang:counter32
                +--ro num-req-rcvd-unknown?     yang:counter32
                +--ro num-req-sent-closed?      yang:counter32
                +--ro num-req-rcvd-closed?      yang:counter32
                +--ro sessions
                   +--ro session* [initiator]
                      +--ro initiator                 pcep-initiator
                      +--ro state-last-change?        yang:timestamp
                      +--ro state?                    pcep-sess-state
                      +--ro connect-retry?            yang:counter32
                      +--ro local-id?                 uint32
                      +--ro remote-id?                uint32
                      +--ro keepalive-timer?          uint32
                      +--ro peer-keepalive-timer?     uint32
                      +--ro dead-timer?               uint32
                      +--ro peer-dead-timer?          uint32



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                      +--ro ka-hold-time-rem?         uint32
                      +--ro overloaded?               boolean
                      +--ro overload-time?            uint32
                      +--ro peer-overloaded?          boolean
                      +--ro peer-overload-time?       uint32
                      +--ro discontinuity-time?       yang:timestamp
                      +--ro avg-rsp-time?             uint32
                      +--ro lwm-rsp-time?             uint32
                      +--ro hwm-rsp-time?             uint32
                      +--ro num-pcreq-sent?           yang:counter32
                      +--ro num-pcreq-rcvd?           yang:counter32
                      +--ro num-pcrep-sent?           yang:counter32
                      +--ro num-pcrep-rcvd?           yang:counter32
                      +--ro num-pcerr-sent?           yang:counter32
                      +--ro num-pcerr-rcvd?           yang:counter32
                      +--ro num-pcntf-sent?           yang:counter32
                      +--ro num-pcntf-rcvd?           yang:counter32
                      +--ro num-keepalive-sent?       yang:counter32
                      +--ro num-keepalive-rcvd?       yang:counter32
                      +--ro num-unknown-rcvd?         yang:counter32
                      +--ro num-corrupt-rcvd?         yang:counter32
                      +--ro num-req-sent?             yang:counter32
                      +--ro num-svec-sent?            yang:counter32
                      +--ro num-svec-req-sent?        yang:counter32
                      +--ro num-req-sent-pend-rep?    yang:counter32
                      +--ro num-req-sent-ero-rcvd?    yang:counter32
                      +--ro num-req-sent-nopath-rcvd? yang:counter32
                      +--ro num-req-sent-cancel-rcvd? yang:counter32
                      +--ro num-req-sent-error-rcvd?  yang:counter32
                      +--ro num-req-sent-timeout?     yang:counter32
                      +--ro num-req-sent-cancel-sent? yang:counter32
                      +--ro num-req-rcvd?             yang:counter32
                      +--ro num-svec-rcvd?            yang:counter32
                      +--ro num-svec-req-rcvd?        yang:counter32
                      +--ro num-req-rcvd-pend-rep?    yang:counter32
                      +--ro num-req-rcvd-ero-sent?    yang:counter32
                      +--ro num-req-rcvd-nopath-sent? yang:counter32
                      +--ro num-req-rcvd-cancel-sent? yang:counter32
                      +--ro num-req-rcvd-cancel-rcvd? yang:counter32
                      +--ro num-rep-rcvd-unknown?     yang:counter32
                      +--ro num-req-rcvd-unknown?     yang:counter32

5.1.  The Entity Lists

   The PCEP yang module may contain status information for multiple
   logical local PCEP entities.  There are several scenarios in which
   there may be more than one local PCEP entity, it is listed in
   [I-D.ietf-pce-pcep-mib].



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   The data model for PCEP presented in this document uses a flat list
   of entities.  Each entity in the list is identified by its IP address
   (addr-type, addr).  Furthermore, each entity has a mandatory "role"
   leaf (the local entity PCEP role).  The ietf-inet-types [RFC6991] is
   used.

   There is one list for configuration ("/pcep/entity"), and a separate
   list for the operational state of all entities ("/pcep-state/
   entity").

   The PCEP MIB module [I-D.ietf-pce-pcep-mib] uses a system generated
   entity index as a primary index to the read only entity table.  If
   the device implements the PCEP MIB, the "index" leaf MUST contain the
   value of the corresponding pcePcepEntityIndex.

5.2.  The Peer Lists

   The peer list contains peer that the local PCEP entity knows about.
   A PCEP speaker is identified by its IP address.  If there is a PCEP
   speaker in the network that uses multiple IP addresses then it looks
   like multiple distinct peers to the other PCEP speakers in the
   network.

   Since PCEP sessions can be ephemeral, the peer list tracks a peer
   even when no PCEP session currently exists to that peer.  The
   statistics contained are an aggregate of the statistics for all
   successive sessions to that peer.

   To limit the quantity of information that is stored, an
   implementation MAY choose to discard this information if and only if
   no PCEP session exists to the corresponding peer.

   The data model for PCEP peer presented in this document uses a flat
   list of peers.  Each peer in the list is identified by its IP address
   (addr-type, addr).

   There is one list for static peer configuration ("/pcep/entity/
   peers"), and a separate list for the operational state of all peers
   (i.e.  static as well as discovered)("/pcep-state/entity/peers").

5.3.  The Session Lists

   The session list contains PCEP session that the PCEP entity (PCE or
   PCC) is currently participating in.  The statistics in session are
   semantically different from those in peer since the former apply to
   the current session only, whereas the latter are the aggregate for
   all sessions that have existed to that peer.




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   Although [RFC5440] forbids there from being more than one active PCEP
   session between a given pair of PCEP entities at any one time, there
   is a window during session establishment where two sessions may exist
   for a given peer, one representing a session initiated by the local
   PCEP entity and one representing a session initiated by the peer.  If
   either of these sessions reaches active state, then the other is
   discarded.

   The data model for PCEP session presented in this document uses a
   flat list of sessions.  Each session in the list is identified by its
   initiator.  This index allows two sessions to exist transiently for a
   given peer, as discussed above.

   There is only one list for the operational state of all sessions
   ("/pcep-state/entity/peers/peer/sessions/session").

6.  Advanced PCE Features

   This document contains a specification of the base PCEP YANG module,
   "ietf-pcep" which provides the basic PCEP [RFC5440] data model.

   A means and procedure to handle to following PCE features needs to be
   decided:

   o  Capability and Scope

   o  Domain information (local/neighbour)

   o  Path-Key

   o  OF

   o  GCO

   o  P2MP

   o  GMPLS

   o  Inter-Layer

   o  Stateful PCE

7.  PCEP YANG Module

   RFC Ed.: In this section, replace all occurrences of 'XXXX' with the
   actual RFC number and all occurrences of the revision date below with
   the date of RFC publication (and remove this note).




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   <CODE BEGINS> file "ietf-pcep@2014-10-09.yang"

   module ietf-pcep {
       namespace "urn:ietf:params:xml:ns:yang:ietf-pcep";
       prefix pcep;

       import ietf-inet-types {
           prefix inet;
       }

       import ietf-yang-types {
           prefix yang;
       }

       organization
           "IETF PCE (Path Computation Element) Working Group";

       contact
           "WG Web:   <http://tools.ietf.org/wg/pce/>
            WG List:  <mailto:pce@ietf.org>

            WG Chair: JP Vasseur
                      <mailto:jpv@cisco.com>

            WG Chair: Julien Meuric
                      <mailto:julien.meuric@orange.com>

            Editor:   Dhruv Dhody
                      <mailto:dhruv.ietf@gmail.com>";

       description
           "The YANG module defines a generic configuration and
            operational model for PCEP common across all of the
            vendor implementations.";


       revision 2014-10-09 {
           description "Initial revision.";
           reference
               "RFC XXXX:  A YANG Data Model for Path Computation
                           Element Communications Protocol
                           (PCEP)";
       }

       /*
        * Identities
        */




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       identity pcep {
           description "Identity for the PCEP protocol.";
       }

       /*
        * Typedefs
        */
       typedef pcep-role {
           type enumeration {
               enum unknown {
                   value "0";
                   description
                   "An unknown role";
               }
               enum pcc {
                   value "1";
                   description
                   "The role of a Path Computation Client";
               }
               enum pce {
                   value "2";
                   description
                   "The role of Path Computation Element";
               }
               enum pcc-and-pce {
                   value "3";
                   description
                   "The role of both Path Computation Client and
                    Path Computation Element";
               }
           }

           description
               "The role of a PCEP speaker.
                Takes one of the following values
                - unknown(0): the role is not known.
                - pcc(1): the role is of a Path Computation
                  Client (PCC).
                - pce(2): the role is of a Path Computation
                  Server (PCE).
                - pccAndPce(3): the role is of both a PCC and
                  a PCE.";

       }

       typedef pcep-admin-status {
           type enumeration {
                   enum admin-status-up {



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                   value "1";
                   description
                   "Admin Status is Up";
               }
               enum admin-status-down {
                   value "2";
                   description
                   "Admin Status is Down";
               }
           }

           description
           "The Admin Status of the PCEP entity.
            Takes one of the following values
                - admin-status-up(1): Admin Status is Up.
                - admin-status-down(2): Admin Status is Down";
       }

       typedef pcep-oper-status {
           type enumeration {
               enum oper-status-up {
                   value "1";
                   description
                   "The PCEP entity is active";
               }
               enum oper-status-down {
                   value "2";
                   description
                   "The PCEP entity is inactive";
               }
               enum oper-status-going-up {
                   value "3";
                   description
                   "The PCEP entity is activating";
               }
               enum oper-status-going-down {
                   value "4";
                   description
                   "The PCEP entity is deactivating";
               }
               enum oper-status-failed {
                   value "5";
                   description
                   "The PCEP entity has failed and will recover
                    when possible.";
               }
               enum oper-status-failed-perm {
                   value "6";



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                   description
                   "The PCEP entity has failed and will not recover
                    without operator intervention";
               }
           }
           description
           "The operational status of the PCEP entity.
            Takes one of the following values
                - oper-status-up(1): Active
                - oper-status-down(2): Inactive
                - oper-status-going-up(3): Activating
                - oper-status-going-down(4): Deactivating
                - oper-status-failed(5): Failed
                - oper-status-failed-perm(6): Failed Permanantly";
       }

       typedef pcep-initiator {
           type enumeration {
               enum local {
                   value "1";
                   description
                   "The local PCEP entity initiated the session";
               }

               enum remote {
                   value "2";
                   description
                   "The remote PCEP peer initiated the session";
               }
           }
           description
           "The initiator of the session, that is, whether the TCP
            connection was initiated by the local PCEP entity or
            the remote peer.
            Takes one of the following values
                - local(1): Initiated locally
                - remote(2): Initiated remotely";
       }

       typedef pcep-sess-state {
           type enumeration {
               enum tcp-pending {
                   value "1";
                   description
                       "The tcp-pending state of PCEP session.";
               }

               enum open-wait {



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                   value "2";
                   description
                       "The open-wait state of PCEP session.";
               }

               enum keep-wait {
                   value "3";
                   description
                       "The keep-wait state of PCEP session.";
               }

               enum session-up {
                   value "4";
                   description
                       "The session-up state of PCEP session.";
               }
           }
           description
               "The current state of the session.

                The set of possible states excludes the idle state
                since entries do not exist in the idle state.
                Takes one of the following values
                   - tcp-pending(1): PCEP TCP Pending state
                   - open-wait(2): PCEP Open Wait state
                   - keep-wait(3): PCEP Keep Wait state
                   - session-up(4): PCEP Session Up state";
       }


       /*
        * Features - TBD
        */

       /*
        * Groupings
        */
       grouping  pcep-entity-identifier{
           description
               "This grouping defines the identifier for PCEP entity.";
           leaf addr-type {
               type inet:ip-version;
               description
                   "The type of the PCEP entity's Internet address.
                    This object specifies how the value of the
                    addr leaf should be interpreted.";
           }




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           leaf addr {
               type inet:ip-address;
               description
                   "The local Internet address of this PCEP entity.
                    The type is given by addr-type.

                    If operating as a PCE server, the PCEP entity
                    listens on this address.

                    If operating as a PCC, the PCEP entity binds
                    outgoing TCP connections to this address.

                    It is possible for the PCEP entity to operate
                    both as a PCC and a PCE Server, in which case it
                    uses this address both to listen for incoming
                    TCP connections and to bind outgoing TCP
                    connections.";
           }
       }

       grouping  pcep-peer-identifier{
           description
               "This grouping defines the identifier for PCEP peer.";
           leaf addr-type {
               type inet:ip-version;
               description
                   "The type of the PCEP peer's Internet address.
                    This object specifies how the value of the
                    addr leaf should be interpreted.";
           }

           leaf addr {
               type inet:ip-address;
               description
                   "The local Internet address of this PCEP peer.
                    The type is given by addr-type.";
           }
       }


       grouping pcep-entity-info{
           description
               "This grouping defines the attributes for PCEP entity.";
           leaf connect-timer {
               type uint32 {
                   range "1..65535";
               }
               units "seconds";



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               default 60;
               description
                   "The time in seconds that the PCEP entity will wait
                    to establish a TCP connection with a peer.  If a
                    TCP connection is not established within this time
                    then PCEP aborts the session setup attempt.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf connect-max-retry {
               type uint32;
               default 5;
               description
                   "The maximum number of times the system tries to
                    establish a TCP connection to a peer before the
                    session with the peer transitions to the idle
                    state.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf init-backoff-timer {
               type uint32 {
                   range "1..65535";
               }
               units "seconds";
               description
                  "The initial back-off time in seconds for retrying
                   a failed session setup attempt to a peer.

                   The back-off time increases for each failed
                   session setup attempt, until a maximum back-off
                   time is reached.  The maximum back-off time is
                   max-backoff-timer.";
           }

           leaf max-backoff-timer {
               type uint32;
               units "seconds";
               description
                  "The maximum back-off time in seconds for retrying
                   a failed session setup attempt to a peer.

                   The back-off time increases for each failed session
                   setup attempt, until this maximum value is reached.



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                   Session setup attempts then repeat periodically
                   without any further increase in back-off time.";
           }

           leaf open-wait-timer {
               type uint32 {
                   range "1..65535";
               }
               units "seconds";
               default 60;
               description
                  "The time in seconds that the PCEP entity will wait
                   to receive an Open message from a peer after the
                   TCP connection has come up.

                   If no Open message is received within this time then
                   PCEP terminates the TCP connection and deletes the
                   associated sessions.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf keep-wait-timer {
               type uint32 {
                   range "1..65535";
               }
               units "seconds";
               default 60;
               description
                   "The time in seconds that the PCEP entity will wait
                    to receive a Keepalive or PCErr message from a peer
                    during session initialization after receiving an
                    Open message.  If no Keepalive or PCErr message is
                    received within this time then PCEP terminates the
                    TCP connection and deletes the associated
                    sessions.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf keep-alive-timer {
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               default 30;



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               description
                   "The keep alive transmission timer that this PCEP
                    entity will propose in the initial OPEN message of
                    each session it is involved in.  This is the
                    maximum time between two consecutive messages sent
                    to a peer. Zero means that the PCEP entity prefers
                    not to send Keepalives at all.

                    Note that the actual Keepalive transmission
                    intervals, in either direction of an active PCEP
                    session, are determined by negotiation between the
                    peers as specified by RFC 5440, and so may differ
                    from this configured value.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf dead-timer {
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               must ". >= ../keep-alive-timer" {
                   description
                       "This value MUST be greater than
                        keep-alive-timer.";

               }
               default 120;
               description
                   "The dead timer that this PCEP entity will propose
                    in the initial OPEN message of each session it is
                    involved in. This is the time after which a peer
                    should declare a session down if it does not
                    receive any PCEP messages. Zero suggests that the
                    peer does not run a dead timer at all." ;
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf allow-negotiation{
               type boolean;
               description
                   "Whether the PCEP entity will permit negotiation of
                    session parameters.";
           }



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           leaf max-keep-alive-timer{
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               description
                   "In PCEP session parameter negotiation in seconds,
                    the maximum value that this PCEP entity will
                    accept from a peer for the interval between
                    Keepalive transmissions. Zero means that the PCEP
                    entity will allow no Keepalive transmission at
                    all." ;
           }

           leaf max-dead-timer{
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               description
                   "In PCEP session parameter negotiation in seconds,
                    the maximum value that this PCEP entity will accept
                    from a peer for the Dead timer.  Zero means that
                    the PCEP entity will allow not running a Dead
                    timer.";
           }

           leaf min-keep-alive-timer{
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               description
                   "In PCEP session parameter negotiation in seconds,
                    the minimum value that this PCEP entity will
                    accept for the interval between Keepalive
                    transmissions. Zero means that the PCEP entity
                    insists on no Keepalive transmission at all.";
           }

           leaf min-dead-timer{
               type uint32 {
                   range "0..255";
               }
               units "seconds";
               description
                    "In PCEP session parameter negotiationin in
                     seconds, the minimum value that this PCEP entity



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                     will accept for the Dead timer.  Zero means that
                     the PCEP entity insists on not running a Dead
                     timer.";
           }

           leaf sync-timer{
               type uint32 {
                   range "0..65535";
               }
               units "seconds";
               default 60;
               description
                   "The value of SyncTimer in seconds is used in the
                    case of synchronized path computation request
                    using the SVEC object. Consider the case where a
                    PCReq message is received by a PCE that contains
                    the SVEC object referring to M synchronized path
                    computation requests.  If after the expiration of
                    the SyncTimer all the M path computation requests
                    have not been, received a protocol error is
                    triggered and the PCE MUST cancel the whole set
                    of path computation  requests.

                    The aim of the SyncTimer is to avoid the storage
                    of unused synchronized requests should one of
                    them get lost for some reasons (for example, a
                    misbehaving PCC).

                    Zero means that the PCEP entity does not use the
                    SyncTimer.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf request-timer{
               type uint32 {
                   range "1..65535";
               }
               units "seconds";
               description
                   "The maximum time that the PCEP entity will wait
                    for a response to a PCReq message.";
           }

           leaf max-sessions{
               type uint32;
               description



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                  "Maximum number of sessions involving this PCEP
                   entity that can exist at any time.";
           }

           leaf max-unknown-reqs{
               type uint32;
               default 5;
               description
                 "The maximum number of unrecognized requests and
                  replies that any session on this PCEP entity is
                  willing to accept per minute before terminating
                  the session.

                  A PCRep message contains an unrecognized reply
                  if it contains an RP object whose request ID
                  does not correspond to any in-progress request
                  sent by this PCEP entity.

                  A PCReq message contains an unrecognized request
                  if it contains an RP object whose request ID is
                  zero.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }

           leaf max-unknown-msgs{
               type uint32;
               default 5;
               description
                "The maximum number of unknown messages that any
                 session on this PCEP entity is willing to accept
                 per minute before terminating the session.";
               reference
                   "RFC 5440: Path Computation Element (PCE)
                              Communication Protocol (PCEP)";
           }
       }//pcep-entity-info

       grouping  pcep-stats{
           description
               "This grouping defines statistics for PCEP. It is used
                for both peer and current session.";
           leaf avg-rsp-time{
               type uint32;
               units "milliseconds";
               description
                 "The average response time.



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                  If an average response time has not been
                  calculated then this leaf has the value zero.

                  If role is pcc then this leaf is meaningless
                  and is set to zero.";
           }

           leaf lwm-rsp-time{
               type uint32;
               units "milliseconds";
               description
                "The smallest (low-water mark) response time seen.

                 If no responses have been received then this
                 leaf has the value zero.

                 If role is pcc then this leaf is meaningless
                 and is set to zero.";
           }

           leaf hwm-rsp-time{
               type uint32;
               units "milliseconds";
               description
                "The greatest (high-water mark) response time seen.

                 If no responses have been received then this object
                 has the value zero.

                 If role is pcc then this field is meaningless and
                 is set to zero.";
           }

           leaf num-pcreq-sent{
               type yang:counter32;
               description
                "The number of PCReq messages sent.";
           }

           leaf num-pcreq-rcvd{
               type yang:counter32;
               description
                 "The number of PCReq messages received.";
           }

           leaf num-pcrep-sent{
               type yang:counter32;
               description



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                 "The number of PCRep messages sent.";
           }

           leaf num-pcrep-rcvd{
               type yang:counter32;
               description
                 "The number of PCRep messages received.";
           }

           leaf num-pcerr-sent{
               type yang:counter32;
               description
                 "The number of PCErr messages sent.";
           }

           leaf num-pcerr-rcvd{
               type yang:counter32;
               description
                 "The number of PCErr messages received.";
           }

           leaf num-pcntf-sent{
               type yang:counter32;
               description
                 "The number of PCNtf messages sent.";
           }

           leaf num-pcntf-rcvd{
               type yang:counter32;
               description
                 "The number of PCNtf messages received.";
           }

           leaf num-keepalive-sent{
               type yang:counter32;
               description
                 "The number of Keepalive messages sent.";
           }

           leaf num-keepalive-rcvd{
               type yang:counter32;
               description
                 "The number of Keepalive messages received.";
           }

           leaf num-unknown-rcvd{
               type yang:counter32;
               description



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                 "The number of unknown messages received.";
           }

           leaf num-corrupt-rcvd{
               type yang:counter32;
               description
                 "The number of corrupted PCEP message received.";
           }

           leaf num-req-sent{
               type yang:counter32;
               description
                 "The number of requests sent.  A request corresponds
                  1:1 with an RP object in a PCReq message. This might
                  be greater than num-pcreq-sent because multiple
                  requests can be batched into a single PCReq
                  message.";
           }

           leaf num-svec-sent{
               type yang:counter32;
               description
                 "The number of SVEC objects sent in PCReq messages.
                  An SVEC object represents a set of synchronized
                  requests.";
           }

           leaf num-svec-req-sent{
               type yang:counter32;
               description
                 "The number of requests sent that appeared in one
                  or more SVEC objects.";
           }

           leaf num-req-sent-pend-rep{
               type yang:counter32;
               description
                 "The number of requests that have been sent for
                  which a response is still pending.";
           }

           leaf num-req-sent-ero-rcvd{
               type yang:counter32;
               description
                  "The number of requests that have been sent for
                   which a response with an ERO object was received.
                   Such responses indicate that a path was
                   successfully computed by the peer.";



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           }

           leaf num-req-sent-nopath-rcvd{
               type yang:counter32;
               description
                 "The number of requests that have been sent for
                  which a response with a NO-PATH object was
                  received. Such responses indicate that the peer
                  could not  find a path to satisfy the
                  request.";
           }

           leaf num-req-sent-cancel-rcvd{
               type yang:counter32;
               description
                 "The number of requests that were cancelled with
                  a PCNtf message.

                  This might be different than num-pcntf-rcvd because
                  not all PCNtf messages are used to cancel requests,
                  and a single PCNtf message can cancel multiple
                  requests.";
           }

           leaf num-req-sent-error-rcvd{
               type yang:counter32;
               description
                "The number of requests that were rejected with a
                 PCErr message.

                 This might be different than num-pcerr-rcvd because
                 not all PCErr messages are used to reject requests,
                 and a single PCErr message can reject multiple
                 requests.";
           }

           leaf num-req-sent-timeout{
               type yang:counter32;
               description
                "The number of requests that have been sent to a peer
                and have been abandoned because the peer has taken too
                long to respond to them.";
           }

           leaf num-req-sent-cancel-sent{
               type yang:counter32;
               description
                "The number of requests that were sent to the peer and



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                 explicitly cancelled by the local PCEP entity sending
                 a PCNtf.";
           }

           leaf num-req-rcvd{
               type yang:counter32;
               description
                "The number of requests received.  A request
                 corresponds 1:1 with an RP object in a PCReq
                 message.

                 This might be greater than num-pcreq-rcvd because
                 multiple requests can be batched into a single
                 PCReq message.";
           }

           leaf num-svec-rcvd{
               type yang:counter32;
               description
                "The number of SVEC objects received in PCReq
                 messages. An SVEC object represents a set of
                 synchronized requests.";
           }

           leaf num-svec-req-rcvd{
               type yang:counter32;
               description
                 "The number of requests received that appeared in one
                  or more SVEC objects.";
           }

           leaf num-req-rcvd-pend-rep{
               type yang:counter32;
               description
                "The number of requests that have been received for
                 which a response is still pending.";
           }

           leaf num-req-rcvd-ero-sent{
               type yang:counter32;
               description
                "The number of requests that have been received for
                 which a response with an ERO object was sent.  Such
                 responses indicate that a path was successfully
                 computed by the local PCEP entity.";
           }

           leaf num-req-rcvd-nopath-sent{



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               type yang:counter32;
               description
                "The number of requests that have been received for
                 which a response with a NO-PATH object was sent. Such
                 responses indicate that the local PCEP entity could
                 not find a path to satisfy the request.";
           }

           leaf num-req-rcvd-cancel-sent{
               type yang:counter32;
               description
                "The number of requests received that were cancelled
                 by the local PCEP entity sending a PCNtf message.

                 This might be different than num-pcntf-sent because
                 not all PCNtf messages are used to cancel requests,
                 and a single PCNtf message can cancel multiple
                 requests.";
           }

           leaf  num-req-rcvd-cancel-rcvd{
               type yang:counter32;
               description
                "The number of requests that were received from the
                 peer and explicitly cancelled by the peer sending
                 a PCNtf.";
           }

           leaf  num-rep-rcvd-unknown{
               type yang:counter32;
               description
                 "The number of responses to unknown requests
                  received. A response to an unknown request is a
                  response whose RP object does not contain the
                  request ID of any request that is currently
                  outstanding on the session.";
           }

           leaf  num-req-rcvd-unknown{
               type yang:counter32;
               description
                 "The number of unknown requests that have been
                  received. An unknown request is a request
                  whose RP object contains a request ID of
                  zero.";
           }

       }//pcep-stats



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       /*
        * Configuration data nodes
        */
       container pcep{

           description
               "Parameters for list of configured PCEP entities
                on the device.";

           list entity{
               key "addr-type addr";

               description
                   "The configured PCEP entity on the device.";

               uses  pcep-entity-identifier {
                   description
                       "The configured PCEP entity Identifier.";
               }

               leaf enabled {
                   type boolean;
                   default true;
                   description
                       "The administrative status of this PCEP
                        Entity.";
               }

               leaf role {
                   type pcep-role;
                   mandatory true;
                   description
                       "The role that this entity can play.
                        Takes one of the following values.
                        - unknown(0): this PCEP Entity role is not
                          known.
                        - pcc(1): this PCEP Entity is a PCC.
                        - pce(2): this PCEP Entity is a PCE.
                        - pcc-and-pce(3): this PCEP Entity is both
                          a PCC and a PCE.";
               }

               leaf description {
                   type string;
                   description
                       "Description of the PCEP entity configured
                        by the user";
               }



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               uses pcep-entity-info {
                   description
                       "The configuration related to the PCEP
                        entity.";
               }

               container peers{
                   description
                           "The list of configured peers for the
                            entity";

                   list peer{
                       key "addr-type addr";

                       description
                           "The peer configured for the entity.";

                        uses pcep-peer-identifier{
                           description
                               "The configured PCEP peer's
                                Identifier.";
                        }

                        leaf description {
                           type string;
                           description
                               "Description of the PCEP peer
                                configured by the user";
                       }
                   }//peer
               }//peers
           }//entity
       }//pcep

       /*
        * Operational data nodes
        */

       container pcep-state{
           config false;
           description
               "The list of operational PCEP entities on the
                device.";

           list entity{
               key "addr-type addr";
               unique "index";




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               description
                   "The operational PCEP entity on the device.";

               leaf index{
                   type uint32;
                   description
                       "The index of the PECP operational
                        entity";
               }

               uses  pcep-entity-identifier {
                   description
                       "The PCEP entity Identifier.";
               }

               leaf admin-status {
                   type pcep-admin-status;
                   description
                       "The administrative status of this PCEP Entity.
                        This is the desired operational status as
                        currently set by an operator or by default in
                        the implementation.  The value of enabled
                        represents the current status of an attempt
                        to reach this desired status.";
               }

               leaf oper-status {
                   type pcep-admin-status;
                   description
                      "The operational status of the PCEP entity.
                       Takes one of the following values.
                       - oper-status-up(1): the PCEP entity is
                         active.
                       - oper-status-down(2): the PCEP entity is
                         inactive.
                       - oper-status-going-up(3): the PCEP entity is
                         activating.
                       - oper-status-going-down(4): the PCEP entity is
                         deactivating.
                       - oper-status-failed(5): the PCEP entity has
                         failed and will recover when possible.
                       - oper-status-failed-perm(6): the PCEP entity
                         has failed and will not recover without
                         operator intervention.";
               }

               leaf role {
                   type pcep-role;



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                   description
                       "The role that this entity can play.
                        Takes one of the following values.
                        - unknown(0): this PCEP entity role is
                          not known.
                        - pcc(1): this PCEP entity is a PCC.
                        - pce(2): this PCEP entity is a PCE.
                        - pcc-and-pce(3): this PCEP entity is
                          both a PCC and a PCE.";
               }


               uses pcep-entity-info{
                   description
                       "The operational information related to the
                        PCEP entity.";
               }

               container peers{
                   description
                           "The list of peers for the entity";

                   list peer{
                       key "addr-type addr";

                       description
                           "The peer for the entity.";

                        uses pcep-peer-identifier{
                           description
                               "The PCEP peer's Identifier.";
                        }

                        leaf role {
                           type pcep-role;
                           description
                               "The role of the PCEP Peer.
                                Takes one of the following values.
                                - unknown(0): this PCEP peer role
                                  is not known.
                                - pcc(1): this PCEP peer is a PCC.
                                - pce(2): this PCEP peer is a PCE.
                                - pcc-and-pce(3): this PCEP peer
                                  is both a PCC and a PCE.";
                       }

                       leaf discontinuity-time {
                           type yang:timestamp;



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                           description
                               "The timestamp of the time when the
                                information and statistics were
                                last reset.";
                       }

                       leaf initiate-session {
                           type boolean;
                           description
                               "Indicates whether the local PCEP
                                entity initiates sessions to this peer,
                                or waits for the peer to initiate a
                                session.";
                       }

                       leaf session-exists{
                           type boolean;
                           description
                               "Indicates whether a session with
                                this peer currently exists.";
                       }

                       leaf num-sess-setup-ok{
                           type yang:counter32;
                           description
                               "The number of PCEP sessions successfully
                                successfully established with the peer,
                                including any current session.  This
                                counter is incremented each time a
                                session with this peer is successfully
                                established.";
                       }

                       leaf num-sess-setup-fail{
                           type yang:counter32;
                           description
                              "The number of PCEP sessions with the peer
                               that have been attempted but failed
                               before being fully established. This
                               counter is incremented each time a
                               session retry to this peer fails.";
                       }

                       leaf session-up-time{
                           type yang:timestamp;
                           description
                              "The timestamp value of the last time a
                               session with this peer was successfully



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                               established.

                               If num-sess-setup-ok is zero, then this
                               leaf contains zero.";
                       }

                       leaf session-fail-time{
                           type yang:timestamp;
                           description
                             "The timestamp value of the last time a
                              session with this peer failed to be
                              established.

                              If num-sess-setup-fail is zero, then
                              this leaf contains zero.";
                       }

                       leaf session-fail-up-time{
                           type yang:timestamp;
                           description
                             "The timestamp value of the last time a
                             session with this peer failed from active.

                             If num-sess-setup-ok is zero, then this
                             leaf contains zero.";
                       }

                       uses pcep-stats{
                           description
                               "Since PCEP sessions can be ephemeral,
                                the peer statistics tracks a peer even
                                when no PCEP session currently exists
                                to that peer. The statistics contained
                                are an aggregate of the statistics for
                                all successive sessions to that peer.";
                       }

                       leaf num-req-sent-closed{
                           type yang:counter32;
                           description
                               "The number of requests that were sent
                                to the peer and implicitly cancelled
                                when the session they were sent over
                                was closed.";
                       }

                       leaf  num-req-rcvd-closed{
                           type yang:counter32;



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                           description
                               "The number of requests that were
                                received from the peer and implicitly
                                cancelled when the session they were
                                received over was closed.";
                       }

                       container sessions {
                           description
                               "This entry represents a single PCEP
                                session in which the local PCEP entity
                                participates.

                                This entry exists only if the
                                corresponding PCEP session has been
                                initialized by some event, such as
                                manual user configuration, auto-
                                discovery of a peer, or an incoming
                                TCP connection.";

                           list session {
                               key "initiator";

                               description
                                   "The list of sessions, note that
                                    for a time being two sessions
                                    may exist for a peer";

                               leaf initiator {
                                   type pcep-initiator;
                                   description
                                       "The initiator of the session,
                                        that is, whether the TCP
                                        connection was initiated by
                                        the local PCEP entity or the
                                        peer.

                                        There is a window during
                                        session initialization where
                                        two sessions can exist between
                                        a pair of PCEP speakers, each
                                        initiated by one of the
                                        speakers. One of these
                                        sessions is always discarded
                                        before it leaves OpenWait state.
                                        However, before it is discarded,
                                        two sessions to the given peer
                                        appear transiently in this MIB



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                                        module. The sessions are
                                        distinguished by who initiated
                                        them, and so this field is the
                                        key.";
                               }

                               leaf state-last-change {
                                   type yang:timestamp;
                                   description
                                       "The timestamp value at the
                                        time this session entered its
                                        current state as denoted by
                                        the state leaf.";
                               }

                               leaf state {
                                   type pcep-sess-state;
                                   description
                                       "The current state of the
                                        session.

                                        The set of possible states
                                        excludes the idle state since
                                        entries do not exist in the
                                        idle state.";
                               }

                               leaf connect-retry {
                                   type yang:counter32;
                                   description
                                        "The number of times that the
                                         local PCEP entity has
                                         attempted to establish a TCP
                                         connection for this session
                                         without success. The PCEP
                                         entity gives up when this
                                         reaches connect-max-retry.";
                               }

                               leaf local-id {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   description
                                        "The value of the PCEP session
                                         ID used by the local PCEP
                                         entity in the Open message
                                         for this session.



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                                         If state is tcp-pending then
                                         this is the session ID that
                                         will be used in the Open
                                         message. Otherwise, this is
                                         the session ID that was sent
                                         in the Open message.";
                               }

                               leaf remote-id {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   description
                                        "The value of the PCEP session
                                         ID
    used by the peer in its
                                         Open message for this session.

                                         If state is tcp-pending or
                                         open-wait then this leaf is not
                                         used and MUST be set to zero.";
                               }

                               leaf keepalive-timer {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   units "seconds";
                                   description
                                        "The agreed maximum interval at
                                         which the local PCEP entity
                                         transmits PCEP messages on this
                                         PCEP session.  Zero means that
                                         the local PCEP entity never
                                         sends Keepalives on this
                                         session.

                                         This field is used if and only
                                         if state is session-up.
                                         Otherwise, it is not used and
                                         MUST be set to zero.";
                               }

                               leaf peer-keepalive-timer {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   units "seconds";



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                                   description
                                        "The agreed maximum interval at
                                         which the peer transmits PCEP
                                         messages on this PCEP session.
                                         Zero means that the peer never
                                         sends Keepalives on this
                                         session.

                                         This field is used if and only
                                         if state is session-up.
                                         Otherwise, it is not used and
                                         MUST be set to zero.";
                               }

                               leaf dead-timer {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   units "seconds";
                                   description
                                        "The dead timer interval for
                                         this PCEP session.";
                               }

                               leaf peer-dead-timer {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   units "seconds";
                                   description
                                        "The peer's dead-timer interval
                                         for this PCEP session.

                                         If state is tcp-pending or
                                         open-wait then this leaf is
                                         not used and MUST be set to
                                         zero.";
                               }

                               leaf ka-hold-time-rem {
                                   type uint32 {
                                     range "0..255";
                                   }
                                   units "seconds";
                                   description
                                        "The keep alive hold time
                                         remaining for this session.




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                                         If state is tcp-pending or
                                         open-wait then this field is
                                         not used and MUST be set to
                                         zero.";
                               }

                               leaf overloaded {
                                   type boolean;
                                   description
                                        "If the local PCEP entity has
                                         informed the peer that it is
                                         currently overloaded, then this
                                         is set to true.  Otherwise, it
                                         is set to false.";
                               }

                               leaf overload-time {
                                   type uint32;
                                   units "seconds";
                                   description
                                        "The interval of time that is
                                         remaining until the local PCEP
                                         entity will cease to be
                                         overloaded on this session.

                                         This field is only used if
                                         overloaded is set to true.
                                         Otherwise, it is not used and
                                         MUST be set to zero.";
                               }

                               leaf peer-overloaded {
                                   type boolean;
                                   description
                                        "If the peer has informed the
                                         local PCEP entity that it is
                                         currently overloaded, then this
                                         is set to true. Otherwise, it
                                         is set to false.";
                               }

                               leaf peer-overload-time {
                                   type uint32;
                                   units "seconds";
                                   description
                                        "The interval of time that is
                                         remaining until the peer will
                                         cease to be overloaded.  If it



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                                         is not known how long the peer
                                         will stay in overloaded state,
                                         this leaf is set to zero.

                                         This field is only used if
                                         peer-overloaded is set to true.
                                         Otherwise, it is not used and
                                         MUST be set to zero.";
                               }

                               leaf discontinuity-time {
                                   type yang:timestamp;
                                   description
                                        "The timestamp value of the time
                                         when the statistics were last
                                         reset.";
                               }

                               uses pcep-stats{
                                   description
                                       "The statistics contained are
                                        for the current sessions to that
                                        peer. These are lost when the
                                        session goes down.";

                               }

                           } // session
                       } // sessions
                   }//peer
               }//peers
           }//entity
       }//pcep-state
   }//module
   <CODE ENDS>
   /* To Do - Notifications, rpc (if any) */

8.  Security Considerations

   This document does not add any new security concerns beyond those
   discussed in [RFC5440].

9.  Manageability Considerations








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9.1.  Control of Function and Policy

9.2.  Information and Data Models

9.3.  Liveness Detection and Monitoring

9.4.  Verify Correct Operations

9.5.  Requirements On Other Protocols

9.6.  Impact On Network Operations

10.  IANA Considerations

11.  Acknowledgements

   The initial document is based on the PCEP MIB
   [I-D.ietf-pce-pcep-mib].  Further this document structure is based on
   Routing Yang Module [I-D.ietf-netmod-routing-cfg].  We would like to
   thank the authors of aforementioned documents.

12.  References

12.1.  Normative References

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

   [RFC5440]  Vasseur, JP. and JL. Le Roux, "Path Computation Element
              (PCE) Communication Protocol (PCEP)", RFC 5440, March
              2009.

   [RFC6020]  Bjorklund, M., "YANG - A Data Modeling Language for the
              Network Configuration Protocol (NETCONF)", RFC 6020,
              October 2010.

   [RFC6991]  Schoenwaelder, J., "Common YANG Data Types", RFC 6991,
              July 2013.

12.2.  Informative References

   [RFC4655]  Farrel, A., Vasseur, J., and J. Ash, "A Path Computation
              Element (PCE)-Based Architecture", RFC 4655, August 2006.








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   [I-D.ietf-pce-pcep-mib]
              Sreenivasa, K., Emile, S., Zhao, Q., King, D., and J.
              Hardwick, "Path Computation Element Communications
              Protocol (PCEP) Management Information Base (MIB) Module",
              draft-ietf-pce-pcep-mib-10 (work in progress), September
              2014.

   [I-D.ietf-netmod-routing-cfg]
              Lhotka, L., "A YANG Data Model for Routing Management",
              draft-ietf-netmod-routing-cfg-15 (work in progress), May
              2014.

   [I-D.ietf-netmod-rfc6087bis]
              Bierman, A., "Guidelines for Authors and Reviewers of YANG
              Data Model Documents", draft-ietf-netmod-rfc6087bis-00
              (work in progress), June 2014.



































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Appendix A.  Contributor Addresses

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

   Phone: (469) 277-5838
   EMail: leeyoung@huawei.com

   Udayasree Palle
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   India

   EMail: udayasree.palle@huawei.com

   Vishnu Pavan Beeram
   Juniper Networks
   USA

   EMail: vbeeram@juniper.net

Authors' Addresses

   Rohit Pobbathi
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   India

   EMail: rohit.pobbathi@huawei.com


   Vinod KumarS
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   India

   EMail: vinods.kumar@huawei.com









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   Dhruv Dhody (editor)
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   India

   EMail: dhruv.ietf@gmail.com


   Jonathan Hardwick
   Metaswitch
   100 Church Street
   Enfield  EN2 6BQ
   UK

   EMail: jonathan.hardwick@metaswitch.com



































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