Network Working Group                                          Y. Tanaka
Internet-Draft                                                 Y. Kamite
Intended status: Standards Track                      NTT Communications
Expires: January 16, 2014                                       I. Minei
                                                  Juniper Networks, Inc.
                                                            Jul 15, 2013


    Stateful PCE Extensions for Data Plane Switchover and Balancing
               draft-tanaka-pce-stateful-pce-data-ctrl-00

Abstract

   Stateful PCE (Path Computation Element) and its corresponding
   protocol extensions provide a mechanism that enables PCE to do
   stateful control of MPLS Traffic Engineering Label Switched Paths (TE
   LSP).  One application that stateful PCE can realize is data traffic
   reoptimization.  Data traffic traversed in a LSP can be switched to
   another PCE-initiated LSP.  Moreover, data traffic can also be
   balanced to multiple PCE-initiated LSPs using stateful PCE.

   This document specifies the extensions to Path Computation Element
   Protocol (PCEP) that allow a stateful PCE to do switchover and
   balancing of data traffic with PCE-initiated LSPs.  This document
   also specifies the usage and handling of stateful PCEP (PCE
   Communication Protocol) messages and the expected behavior of PCC as
   the RSVP-TE headend.

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 January 16, 2014.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the



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   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
   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
   2.  Conventions used in this document  . . . . . . . . . . . . . .  4
   3.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   4.  PCEP Operation for Data Switchover and Balancing . . . . . . .  4
   5.  TLVs in LSP Objects  . . . . . . . . . . . . . . . . . . . . .  6
     5.1.  ASSOCIATION-GROUP TLV in LSP Objects . . . . . . . . . . .  6
     5.2.  DATA-CONTROL TLV in LSP Objects  . . . . . . . . . . . . .  7
   6.  Operation Examples . . . . . . . . . . . . . . . . . . . . . .  9
     6.1.  Data switchover operation (100:0 => 0:100) . . . . . . . .  9
     6.2.  Load balancing operation (100:0 => 50:50)  . . . . . . . . 11
   7.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 12
     7.1.  PCEP TLV Indicators  . . . . . . . . . . . . . . . . . . . 12
     7.2.  PCEP Error Objects . . . . . . . . . . . . . . . . . . . . 12
   8.  Security Considerations  . . . . . . . . . . . . . . . . . . . 13
   9.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 13
   10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
     10.1. Normative References . . . . . . . . . . . . . . . . . . . 13
     10.2. Informative References . . . . . . . . . . . . . . . . . . 14
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14

















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1.  Introduction

   [I-D.ietf-pce-stateful-pce] describes the stateful Path Computation
   Elements(PCE).  Stateful PCE defines the extensions to PCEP to enable
   stateful control of LSPs between and across PCEP sessions, and it
   also describes mechanisms to effect LSP state synchronization between
   PCCs and PCEs, and PCE control of timing and sequence of path
   computations within and across PCEP sessions.  A PCE can update LSP
   settings (such as bandwidth, priority) using update messages calle
   PCUpd.

   [I-D.crabbe-pce-pce-initiated-lsp] defines the exensions to PCEP to
   allow a PCE to create new LSPs (PCE-Initiated LSP).  Before these
   extensions, the LSP egress point had to be preconfigured at the head
   end Label Edge Router (LER), the LSP would be set up with default
   parameters and then its settings (e.g., initial bandwidth, priority)
   could be modified via PCUpd messages.  The extensions for PCE-
   initated LSPs eliminate the need for preconfiguration, and allow more
   flexible operation.  Stateful-PCE with LSP instantiation is
   attracting attention as an enabler for Software Defined Networking
   (SDN) operation of MPLS networks.

   In SDN, it is highly expected to support intelligent and interactive
   control of the traffic amount of the network by means of a logically-
   centralized controller.  Optimizing the path and bandwidth of MPLS-TE
   LSP by using stateful PCE is a leading use case of SDN applications.
   A PCE is able to calculate an optimized route from the topology and
   bandwidth information in the TED and the LSP state database and it
   can integrate with a controller that takes into account additional
   information such as historical trending and service orders in order
   to trigger PCE action.  For example, when data traffic on a LSP
   counts plenty of bandwidth utilization and if there is no capacity
   left in the currently signaled path (i.e., no remaining bandwidth of
   links), a PCE is able to update the existing LSP's parameters (PCE-
   updated LSP) or create a totally new LSP (PCE-initiated LSP).

   The former method is oriented for keeping the existing instance of
   LSP tunnel, so it does not change a pair of source and destination.
   Meanwhile, the latter method is oriented for adding a new instance of
   LSP tunnel.

   Specifically regarding the latter method, PCE-initiated LSP, there
   are some operational scenarios in the network: one is that PCE
   creates a new LSP that have alternate route with increased-bandwidth
   LSP and performs switchover from old LSP.  Another is that PCE
   creates one or more additional LSPs and performs load balancing of
   data traffic.  Today, however, there is no detailed procedure
   specified as to how to control data traffic switching from an old LSP



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   to new PCE-Initiated LSP(s).

   This document specifies the procedures that stateful PCE controls
   data traffic switchover and load balancing with multiple PCE-
   Initiated LSPs.  This document also specifies the usage and handling
   of stateful PCEP ( PCE Communication Protocol) messages and the
   expected behavior of PCC as an RSVP-TE headend.


2.  Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC2119[RFC2119].


3.  Terminology

   This document uses the following terms defined in [RFC5440]: PCC,
   PCE, PCEP Peer.

   This document uses the following terms defined in
   [I-D.ietf-pce-stateful-pce]: Stateful PCE, LSP State Request, LSP
   Update Request.

   This document uses the following terms defined in
   [I-D.crabbe-pce-pce-initiated-lsp]: LSP Create Request message.

   The message formats in this document are specified using Backus-Naur
   Format (BNF) encoding as specified in [RBNF].


4.  PCEP Operation for Data Switchover and Balancing

   There are two typical operations for explaining the functionality of
   data switchover and balancing.  One is whole data switchover, where a
   PCC switches all data traffic from one LSP tunnel to another.  The
   other is load balancing of multi-pathing LSP tunnels, where a PCC
   (headend) balances data traffic among two tunnels equally (fifty
   percent each, for instance).  Both operational cases are completed by
   the messaging over a single protocol, PCEP, so this is a simple and
   straightforward solution for MPLS networks.

   Support of the procedures listed in this document is negotiated at
   session init time.  The capability negotiation will be speleld out in
   a future version of this document.

   Data switchover and balancing for an MPLS-TE LSP is available once a



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   PCEP session is established and then a PCC delegates its LSPs to a
   PCE.

   First step is LSP creation.  In this step, a PCE sends as many
   PCInitiate messages as PCE-Initiated LSP as it demands.  Once the PCC
   receives them and successfully establishes PCE-Initiated LSPs, it
   sends PCRpt messages in reply to the PCInitiate messages and
   delegates the newly established LSP to the PCE.  Message formats and
   behaviors of the PCC and the PCE are described in detail in
   [I-D.crabbe-pce-pce-initiated-lsp].

   Second step is LSP association.  After the PCE-Initiated LSP
   sucessfully established and delegated the PCE sends a PCUpd message
   that contains the ASSOCIATION-GROUP TLV in the LSP Object in order to
   assemble the members of an association group of LSPs to take over the
   traffic.  Once a PCC receives the PCUpd message with ASSOCIATION-
   GROUP TLV, the PCC sends back a PCRpt message that contains the
   ASSOCIATION-GROUP TLV with current operational status.

   The option of specifying the association at LSP instantiation time
   (as part of the PCInitiate message) will be evaluated in a future
   version of this document.

   Third step is executing the data switchover and/or load balancing.
   In this step, the PCE sends a single PCUpd message which updates the
   operational status of the LSP from "up and carrying traffic" to just
   "up".  This Update request message for data plane switchover/
   balancing execution MUST contain DATA-CONTROL TLV in LSP Object.  The
   associated group of traffic origin and that of target to take over
   the traffic are listed in the DATA-CONTROL TLV.  The PCC (LSP
   headend) load-balances between LSPs in the same association group
   based on their respective bandwidths.  If one of the LSPs does not
   come up, the traffic would load balance correctly over the others.
   The switchover case is supported since there will be an association
   of a single LSP, so that LSP will get hundred percent of data
   traffic.

   The PCC MUST send a PCRpt message to the PCE in order to notify of
   the result of the data switchover/balancing.  The PCRpt message MUST
   have the DATA-CONTROL TLV that indicates the actual assigned
   percentages of each member of association group after the execution
   of the data switchover/balancing operation.  The LSP object in the
   PCRpt will have the reserved PLSP-ID of 0.

   The final step is the deletion of old LSP.  It is OPTIONAL to carry
   out this step.  The PCE sends PCInitiate message requesting deletion
   of the LSP that does not carry data traffic anymore after data
   switchover/balancing execution.  Once the PCC tears down the LSP, a



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   PCRpt message MUST be sent from the PCC to the PCE in order to notify
   that the LSP is no longer used and return delegation.

   Note that, both RSVP-TE [RFC3209] Tunnel-ID and LSP-ID for PCE-
   Initiated LSP signaling is not allocated by a PCE.  A PCC locally
   assigns those IDs that are related to RSVP-TE parameters.  Therefore,
   the operations of data switchover and balancing specified in this
   document is the traffic control procedure across multiple RSVP-te
   Tunnels (i.e., different Tunnel instances).  Data switchover method
   across LSPs within a single RSVP-TE Tunnel, which is the switchover
   in the middle of make-before-break reoptimization, is covered by
   [I-D.tanaka-pce-stateful-pce-mbb].


5.  TLVs in LSP Objects

5.1.  ASSOCIATION-GROUP TLV in LSP Objects

   This section defines ASSOCIATION-GROUP TLV in LSP Objects.
   ASSOCIATION-GROUP TLV is used in the LSP Object in PCUpd messages
   when a PCE creates association group of LSPs on a PCC.


    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=TBD            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |        Flags                  |      Association Group ID     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+




                  Figure 1: ASSOCIATION-GROUP TLV format

   Flags and fields

      Association Group ID - 8 bit:   This field specifies a identifier
         of association group of LSPs.  The IDs are assigned by a PCE,
         however a PCC (RSVP headend) owns the association group. 0x0000
         and 0xFFFF is reserved for special use.
      Flags - 8 bit:   None defined.  MUST be set to zero.

   An association group is a group of LSPs that is referenced by a
   single identifier, by both the PCE and PCC.  This number is
   significant in the context of a single PCEP session.  An association
   group may have one or more LSPs.  Association groups with zero



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   members are removed and the id can be reused.  The PCE is the entity
   managing association, and this is considered PCE state that will be
   cleaned up when the State Timeout Interval expires.  An LSP can be
   associated with a single association group.  Extensions for support
   of multiple association groups are left for a future version of this
   document.

   To create a new association group on a PCC, a PCE sends a PCUpd
   message which contains the LSP Object(e.g.  PLSP-ID=100) and
   ASSOCIATION-GROUP TLV (Association Group ID=10) in the LSP object.
   Next, a PCE sends the another PCUpd message with another LSP
   Object(e.g.  PLSP-ID=200) and ASSOIATION-GROUP TLV(Association Group
   ID=10).  As a result, the PCC and PCE both recognize that Association
   Group ID 10 represents PLSP-ID=100 and 200.

   To remove a specific PLSP-ID from the association group, a PCE sends
   PCUpd message which contains the LSP Object(PLSP-ID=100) and
   ASSOCIATION-GROUP TLV (Association Group ID=0x0000).  Then a PCC
   removes the PLSP-ID 100 from any association groups on the PCC.

   To flush all association groups on a PCC, a PCE sends a PCUpd message
   which contains the LSP Object(PLSP-ID=0x0000) and ASSOCIATION-GROUP
   TLV(Association Group ID=0x0000).  Then a PCC flushes all association
   groups.

5.2.  DATA-CONTROL TLV in LSP Objects

   This document defines DATA-CONTROL TLV in LSP Objects.


    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=TBD            |           Length              |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Origin Association Group ID  |        Flags            |  O  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |  Target Association Group ID  |        Flags            |  O  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |               (OPTIONAL)  DATA-REPORT TLV                     |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                     Figure 2: DATA-CONTROL TLV format






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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=TBD            |           Length              |
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
   |      Member 1 (PLSP-ID )      |   MUST Zero   |   Percentage  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Member 2 (PLSP-ID )      |   MUST Zero   |   Percentage  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   //                                                              //
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |      Member N (PLSP-ID )      |   MUST Zero   |   Percentage  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                     Figure 3: DATA-REPORT TLV format

   Flags and fields

      Origin Association Group ID:   data traffic origin
      Target Association Group ID:   for taking over whole data traffic
         from origin.
      O (Operational - 3 bit):   This bit represents the requested
         operational status by a PCE.  The meanings of the values are
         defined in [I-D.ietf-pce-stateful-pce].
      Member in DATA-REPORT TLV:  This TLV is used in a PCRpt message
         and represents actual percentages of load balancing per
         respective PLSP-ID after load balancing execution.  Member
         field fills PLSP-ID that is member of target association group.
      Percentage in DATA-REPORT TLV - 8 bit:   This field specifies
         actual percentage of load balancing as an unsigned char.

   An LSP Object in PCCUpd message MUST have DATA-CONTROL TLV when a PCE
   operates data switchover and balancing on a PCC.  DATA-CONTROL TLV is
   sub-TLV of an LSP Object and is used in both PCUpd and PCRpt message.

   An operation of data switchover/balancing is the action of
   transferring traffic from an origin association group to a target
   association group.  A PCUpd message with reserved LSP Object (PLSP-
   ID=0x0000) and DATA-CONTROL TLV (a set of an origin and a target
   association group) MUST triggers data switchover/balancing execution.

   A PCC replies to a PCE a PCRpt message as a notification of data '
   switchover/balancing result.  The PCRpt message MUST have reserved
   LSP Object(PLSP-ID=0x0000) and DATA-CONTROL TLV with DATA-REPORT
   inside.




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6.  Operation Examples

   For easy understanding this section introduces typical operation
   examples of data switchover/balancing.

6.1.  Data switchover operation (100:0 => 0:100)

   A PCE instructs a PCC to switchover 100% traffic from association
   group ID 1 to association group ID 2.  A PCE sends single PCUpd
   message containing the reserved LSP Objects with DATA-CONTROL TLV.

   Expected PCUpd,PCRpt messages to create association group and to
   trigger data switchover follow.






































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    PCE                         PCC(Ingress)     Egress
   [LSP Association for existing LSP]
     |                           |                |
     | --PCUpd ----------------->|                |
     |   LSP Obj: PLSP-ID=1      |                |
     |   + ASSOC-G: Assoc-G-ID 10|                |
     |                           |                |
     |<--PCRpt ----------------- |                |
     |   LSP Obj: PLSP-ID=1      |                |
     |   + ASSOC-G: Assoc-G-ID 10|                |

   [LSP Creation]
     |                           |                |
     | --PCInitiate ------------>|                |
     |                           | --Path ------->|
     |                           |<------- Resv-- | Establish a new
     |<--PCRpt ----------------- |                | PCE-Initiated LSP
     |   LSP Obj: PLSP-ID=2      |                |
     |                           |                |

   [LSP Association for PCE-Initiated LSP]
     |                           |                |
     | --PCUpd ----------------->|                |
     |   LSP Obj: PLSP-ID=2      |                |
     |   + ASSOC-G: Assoc-G-ID 20|                |
     |                           |                |
     |<--PCRpt ----------------- |                |
     |   LSP Obj: PLSP-ID=2      |                |
     |   + ASSOC-G: Assoc-G-ID 20|                |
     |                           |                |

   [Switchover Execution]
     |                           |                |
     | --PCUpd ----------------->|                |
     |   LSP Obj: PLSP-ID=0x0000 |                |
     |   + D-CTRL:               |        :       |
     |    Origin Assoc-G-ID 10(O=up)      :       |
     |    Target Assoc-G-ID 20(O=active)  :       |
     |                           |))))))))))))))))| Switchover
     |                           |}}}}}}}}}}}}}}}}| Execution
     |<--PCRpt------------------ |        :       |
     |   LSP Obj: PLSP-ID=0x0000 |        :       |
     |   + D-CTRL:               |        :       |
     |    Origin Assoc-G-ID 10(O=up)              |
     |    Target Assoc-G-ID 20(O=active)          |
     |    + D-REPORT:            |                |
     |      PLSP-ID 2, 100%      |                |
     |                           |                |



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                  Figure 4: Switchover Operation Example

6.2.  Load balancing operation (100:0 => 50:50)

   The scenario is one where the starting state is a single LSP (of
   bandwidth 100 M) is carrying the traffic.  To enable better bin-
   packing, the PCE may want to create two smaller LSPs instead, each of
   50M, and load balance the traffic over them.  To accomplish this, two
   association groups are used, the first (say association group ID 10)
   contains the LSP carrying the traffic, and the second (say
   association group ID 30) contains the two new smaller LSPs.  Expected
   PCUpd,PCRpt messages to create association group and to trigger load-
   balance follow (The instantiation of the original LSP of bandwidth
   100M and its association into group ID 10 is not shown)

    PCE                         PCC(Ingress)     Egress

   [LSP Creation]
     |                           |                |
     | --PCInitiate x2---------->|                |
     |      BW: 50M              | --Path x2----->|
     |                           |<-----Resv x2-- | Establish two new
     |<--PCRpt ----------------- |                | PCE-Initiated LSP
     |   LSP Obj: PLSP-ID=3      |                |
     |<--PCRpt ----------------- |                |
     |   LSP Obj: PLSP-ID=4      |                |
     |                           |                |


   [LSP Association for PCE-Initiated LSPs]
     |                           |                |
     | --PCUpd ----------------->|                | Create new
     |   LSP Obj: PLSP-ID=3      |                | Association Group
     |   + ASSOC-G: Assoc-G-ID 30|                | for PCE-Initiated
     |                           |                | LSP
     |<--PCRpt ----------------- |                |
     |   LSP Obj: PLSP-ID=3      |                |
     |   + ASSOC-G: Assoc-G-ID 30|                |
     |                           |                |
     | --PCUpd ----------------->|                | Add a new LSP
     |   LSP Obj: PLSP-ID=4      |                | to Association Group
     |   + ASSOC-G: Assoc-G-ID 30|                |
     |                           |                |
     |<--PCRpt ----------------- |                |
     |   LSP Obj: PLSP-ID=4      |                |
     |   + ASSOC-G: Assoc-G-ID 30|                |





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   [Load Balancing Execution]
     | --PCUpd------------------>|                |
     |   LSP Obj: PLSP-ID=0x0000 |                |
     |   + D-CTRL:               |        :       |
     |    Origin Assoc-G-ID 10(O=up)      :       |
     |    Target Assoc-G-ID 30(O=active)  :       |
     |                           |))))))))))))))))| Balancing
     |                           |)})})})})})})})}| Execution
     |                           |        :       |
     |<--PCRpt------------------ |        :       |
     |   LSP Obj: PLSP-ID=0x0000 |        :       |
     |   + D-CTRL:               |        :       |
     |    Origin Assoc-G-ID 10(O=up)              |
     |    Target Assoc-G-ID 30(O=active)          |
     |    + D-REPORT:            |                |
     |      PLSP-ID 3, 50%       |                |
     |      PLSP-ID 4, 50%       |                |
     |                           |                |




                 Figure 5: Load-Balance Operation Example


7.  IANA Considerations

7.1.  PCEP TLV Indicators

   This document defines the following new PCEP TLVs:

     Value     Meaning              Reference
       TBD     DATA-CONTROL         This document
       TBD     DATA-REPORT          This document



7.2.  PCEP Error Objects

   This document defines new Error-Type and Error-Value for the
   following new error conditions:










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    Error-Type  Meaning
       6        Mandatory Object missing
                 Error-value=TBD:  DATA-CONTROL TLV missing.
                 Error-value=TBD:  DATA-REPORT TLV missing.

       19       Invalid operation
                 Error-value=TBD:  No association group existing.
                 Error-value=TBD:  No association group specified.




8.  Security Considerations

   TBD


9.  Acknowledgments

   Many thanks to Adrian Farrel for his ideas and suggestions.


10.  References

10.1.  Normative References

   [I-D.crabbe-pce-pce-initiated-lsp]
              Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "PCEP
              Extensions for PCE-initiated LSP Setup in a Stateful PCE
              Model", draft-crabbe-pce-pce-initiated-lsp-02 (work in
              progress), July 2013.

   [I-D.ietf-pce-stateful-pce]
              Crabbe, E., Medved, J., Minei, I., and R. Varga, "PCEP
              Extensions for Stateful PCE",
              draft-ietf-pce-stateful-pce-05 (work in progress),
              July 2013.

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

   [RFC4872]  Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
              Extensions in Support of End-to-End Generalized Multi-
              Protocol Label Switching (GMPLS) Recovery", RFC 4872,
              May 2007.

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



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Internet-Draft       Data Control using Stateful PCE            Jul 2013


              March 2009.

10.2.  Informative References

   [I-D.tanaka-pce-stateful-pce-mbb]
              Tanaka, Y. and Y. Kamite, "Make-Before-Break MPLS-TE LSP
              restoration and reoptimization procedure using Stateful
              PCE", draft-tanaka-pce-stateful-pce-mbb-00 (work in
              progress), February 2013.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, December 2001.


Authors' Addresses

   Yosuke Tanaka
   NTT Communications Corporation
   Granpark Tower
   3-4-1 Shibaura, Minato-ku
   Tokyo  108-8118
   Japan

   Email: yosuke.tanaka@ntt.com


   Yuji Kamite
   NTT Communications Corporation
   Granpark Tower
   3-4-1 Shibaura, Minato-ku
   Tokyo  108-8118
   Japan

   Email: y.kamite@ntt.com


   Ina Minei
   Juniper Networks, Inc.
   1194 N. Mathilda Ave.
   Sunnyvale, CA  94089
   US

   Email: ina@juniper.net







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