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Versions: 00 01 02 03 draft-ietf-pce-pcep-service-aware

PCE Working Group                                                  Q. Wu
Internet-Draft                                                  D. Dhody
Intended status: Standards Track                                  Huawei
Expires: December 26, 2014                                    S. Previdi
                                                      Cisco Systems, Inc
                                                           June 24, 2014


Extensions to Path Computation Element Communication Protocol (PCEP) for
                handling the Link Bandwidth Utilization
                draft-wu-pce-pcep-link-bw-utilization-03

Abstract

   The Path Computation Element Communication Protocol (PCEP) provides
   mechanisms for Path Computation Elements (PCEs) to perform path
   computations in response to Path Computation Clients (PCCs) requests.

   The Link bandwidth utilization (the total bandwidth of a link in
   current use for the forwarding) is an important factor to consider
   during path computation.  [OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS]
   define mechanisms that distribute this information via OSPF and ISIS
   respectively.  This document describes extensions to PCEP to use them
   as new constraints during path computation.

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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on December 26, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





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

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Link Bandwidth Utilization (LBU)  . . . . . . . . . . . . . .   4
   4.  Link Reserved Bandwidth Utilization (LRBU)  . . . . . . . . .   4
   5.  PCEP Requirements . . . . . . . . . . . . . . . . . . . . . .   5
   6.  PCEP Extensions . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  BU Object . . . . . . . . . . . . . . . . . . . . . . . .   5
       6.1.1.  Elements of Procedure . . . . . . . . . . . . . . . .   6
     6.2.  New Objective Functions . . . . . . . . . . . . . . . . .   7
     6.3.  PCEP Message Extension  . . . . . . . . . . . . . . . . .   8
       6.3.1.  The PCReq message . . . . . . . . . . . . . . . . . .   8
       6.3.2.  The PCRep message . . . . . . . . . . . . . . . . . .   9
   7.  Other Considerations  . . . . . . . . . . . . . . . . . . . .  10
     7.1.  Reoptimization Consideration  . . . . . . . . . . . . . .  10
     7.2.  Inter-domain Consideration  . . . . . . . . . . . . . . .  10
       7.2.1.  Inter-AS Link . . . . . . . . . . . . . . . . . . . .  10
     7.3.  P2MP Consideration  . . . . . . . . . . . . . . . . . . .  10
     7.4.  Stateful PCE  . . . . . . . . . . . . . . . . . . . . . .  10
       7.4.1.  PCEP Message Extension  . . . . . . . . . . . . . . .  11
         7.4.1.1.  The PCRpt message . . . . . . . . . . . . . . . .  11
   8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  11
     8.1.  New PCEP Object . . . . . . . . . . . . . . . . . . . . .  11
     8.2.  BU Object . . . . . . . . . . . . . . . . . . . . . . . .  12
     8.3.  Objective Functions . . . . . . . . . . . . . . . . . . .  12
   9.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
   10. Manageability Considerations  . . . . . . . . . . . . . . . .  12
     10.1.  Control of Function and Policy . . . . . . . . . . . . .  12
     10.2.  Information and Data Models  . . . . . . . . . . . . . .  12
     10.3.  Liveness Detection and Monitoring  . . . . . . . . . . .  13
     10.4.  Verify Correct Operations  . . . . . . . . . . . . . . .  13
     10.5.  Requirements On Other Protocols  . . . . . . . . . . . .  13
     10.6.  Impact On Network Operations . . . . . . . . . . . . . .  13
   11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .  13
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
     12.1.  Normative References . . . . . . . . . . . . . . . . . .  13



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     12.2.  Informative References . . . . . . . . . . . . . . . . .  13
   Appendix A.  Contributor Addresses  . . . . . . . . . . . . . . .  15

1.  Introduction

   The link bandwidth utilization based on real time traffic along the
   path is becoming critical during path computation in some networks.
   Thus it is important that the link bandwidth utilization is factored
   in during path computation.  A PCC can request a PCE to provide a
   path such that it selects under-utilized links.  This document
   extends PCEP [RFC5440] for this purpose.

   The Traffic Engineering Database (TED) as populated by the Interior
   Gateway Protocol (IGP) contains the Maximum bandwidth, the Maximum
   reservable bandwidth and the Unreserved bandwidth ([RFC3630] and
   [RFC3784]).  [OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] further populate
   the Residual bandwidth, the Available bandwidth and the Utilized
   bandwidth.

   The links in the path MAY be monitored for changes in the link
   bandwidth utilization, re-optimization of such path MAY be further
   requested.

   [OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS] also include parameters
   related to link latency, latency variation and packet loss.
   [PCE-SERVICE-AWARE] describes extensions to PCEP to consider them.

1.1.  Requirements Language

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

2.  Terminology

   The following terminology is used in this document.

   IGP:  Interior Gateway Protocol.  Either of the two routing
      protocols, Open Shortest Path First (OSPF) or Intermediate System
      to Intermediate System (IS-IS).

   LBU:  Link Bandwidth Utilization.  (See Section 3.)

   LRBU:  Link Reserved Bandwidth Utilization.  (See Section 4.)

   MRUP:  Maximum Reserved Under-Utilized Path.  (See Section 6.2.)

   MUP:  Maximum Under-Utilized Path.  (See Section 6.2.)



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   OF:  Objective Function.  A set of one or more optimization criteria
      used for the computation of a single path (e.g., path cost
      minimization) or for the synchronized computation of a set of
      paths (e.g., aggregate bandwidth consumption minimization, etc).
      (See [RFC5541].)

   PCC:  Path Computation Client: any client application requesting a
      path computation to be performed by a Path Computation Element.

   PCE:  Path Computation Element.  An entity (component, application,
      or the network node) that is capable of computing a network path
      or the route based on a network graph and applying computational
      constraints.

   PCEP:  Path Computation Element Communication Protocol.

   RSVP:  Resource Reservation Protocol

   TE LSP:  Traffic Engineering Label Switched Path.

3.  Link Bandwidth Utilization (LBU)

   The bandwidth utilization on a link, forwarding adjacency, or bundled
   link is populated in the TED (Utilized Bandwidth in [OSPF-TE-EXPRESS]
   and [ISIS-TE-EXPRESS]).  For a link or forwarding adjacency, the
   bandwidth utilization represents the actual utilization of the link
   (i.e., as measured in the router).  For a bundled link, the bandwidth
   utilization is defined to be the sum of the component link bandwidth
   utilization.  This includes traffic for both RSVP and non-RSVP.

   LBU Percentage is described as the (LBU / Maximum bandwidth) * 100.

4.  Link Reserved Bandwidth Utilization (LRBU)

   The reserved bandwidth utilization on a link, forwarding adjacency,
   or bundled link can be calculated from the TED.  This includes
   traffic for only RSVP-TE LSPs.

   LRBU can be calculated by using the Residual bandwidth, the Available
   bandwidth and LBU.  The actual bandwidth by non-RSVP TE traffic can
   be calculated by subtracting the Available Bandwidth from the
   Residual Bandwidth.  Once we have the actual bandwidth for non-RSVP
   TE traffic, subtracting this from LBU would result in LRBU.

   LRBU Percentage is described as the (LRBU / (Maximum reservable
   bandwidth)) * 100.





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5.  PCEP Requirements

   The following requirements associated with the bandwidth utilization
   are identified for PCEP:

   1.  The PCE supporting this document MUST have the capability to
       compute end-to-end path with the bandwidth utilization
       constraints.  It MUST also support the combination of the
       bandwidth utilization constraint with the existing constraints
       (cost, hop-limit...).

   2.  The PCC MUST be able to request for the bandwidth utilization
       constraint in PCReq message as the upper limit that should not be
       crossed for each link in the path.

   3.  The PCC MUST be able to request for the bandwidth utilization
       constraint in PCReq message as an Objective function (OF)
       [RFC5541] to be optimized.

   4.  PCEs are not required to support the bandwidth utilization
       constraint.  Therefore, it MUST be possible for a PCE to reject a
       PCReq message with a reason code that indicates no support for
       the bandwidth utilization constraint.

   5.  PCEP SHOULD provide a mechanism to handle the bandwidth
       utilization constraint in multi-domain (e.g., Inter-AS, Inter-
       Area or Multi-Layer) environment.

6.  PCEP Extensions

   This section defines extensions to PCEP [RFC5440] to meet
   requirements outlined in Section 5.  The proposed solution is used to
   consider the bandwidth utilization during path computation.

6.1.  BU Object

   The BU (the Bandwidth Utilization) is used to indicate the upper
   limit of the acceptable link bandwidth utilization percentage.

   The BU object may be carried within the PCReq message and PCRep
   messages.

   BU Object-Class is TBD.

   BU Object-Type is 1.

   The format of the BU object body is as follows:




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       0                   1                   2                   3
       0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |              Reserved                         |    Type       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Bandwidth Utilization                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                           BU Object Body Format

   Reserved (24 bits):  This field MUST be set to zero on transmission
      and MUST be ignored on receipt.

   Type (8 bits):  Represents the bandwidth utilization type.  Link
      Bandwidth Utilization (LBU) Type is 1 and Link Reserved Bandwidth
      Utilization (LRBU) Type is 2.

   Bandwidth utilization (32 bits):  Represents the bandwidth
      utilization quantified as a percentage (as described in Section 3
      and Section 4).  The basic unit is 0.000000023%, with the maximum
      value 4,294,967,295 representing 98.784247785% (4,294,967,295 *
      0.000000023%).  This value is the maximum Bandwidth utilization
      percentage that can be expressed.

   The BU object body has a fixed length of 8 bytes.

6.1.1.  Elements of Procedure

   A PCC SHOULD request the PCE to factor in the bandwidth utilization
   during path computation by including a BU object in the PCReq
   message.

   Multiple BU objects MAY be inserted in a PCReq or a PCRep message for
   a given request but there MUST be at most one instance of the BU
   object for each type.  If, for a given request, two or more instances
   of a BU object with the same type are present, only the first
   instance MUST be considered and other instances MUST be ignored.

   BU object MAY be carried in a PCRep message in case of unsuccessful
   path computation along with a NO-PATH object to indicate the
   constraints that could not be satisfied.

   If the P bit is clear in the object header and PCE does not
   understand or does not support the bandwidth utilization during path
   computation it SHOULD simply ignore BU object.





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   If the P Bit is set in the object header and PCE receives BU object
   in path request and it understands the BU object, but the PCE is not
   capable of the bandwidth utilization check during path computation,
   the PCE MUST send a PCErr message with a PCEP-ERROR Object Error-Type
   = 4 (Not supported object) [RFC5440].  The path computation request
   MUST then be cancelled.

   If the PCE does not understand the BU object, then the PCE MUST send
   a PCErr message with a PCEP-ERROR Object Error-Type = 3 (Unknown
   object) [RFC5440].

6.2.  New Objective Functions

   This document defines two additional objective functions -- namely,
   MUP (the Maximum Under-Utilized Path) and MRUP (the Maximum Reserved
   Under-Utilized Path).  Hence two new objective function codes have to
   be defined.

   Objective functions are formulated using the following terminology:

   o  A network comprises a set of N links {Li, (i=1...N)}.

   o  A path P is a list of K links {Lpi,(i=1...K)}.

   o  The Bandwidth Utilization on link L is denoted u(L).

   o  The Reserved Bandwidth Utilization on link L is denoted ru(L).

   o  The Maximum bandwidth on link L is denoted M(L).

   o  The Maximum Reserved bandwidth on link L is denoted R(L).

   The description of the two new objective functions is as follows.

   Objective Function Code:  TBD



         Name: Maximum Under-Utilized Path (MUP)

         Description: Find a path P such that (Min {(M(Lpi)- u(Lpi)) /
         M(Lpi), i=1...K } ) is maximized.

   Objective Function Code:  TBD



         Name: Maximum Reserved Under-Utilized Path (MRUP)



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         Description: Find a path P such that (Min {(R(Lpi)- ru(Lpi)) /
         R(Lpi), i=1...K } ) is maximized.

   These new objective functions are used to optimize paths based on the
   bandwidth utilization as the optimization criteria.

   If the objective function defined in this document are unknown/
   unsupported, the procedure as defined in [RFC5541] is followed.

6.3.  PCEP Message Extension

6.3.1.  The PCReq message

   The new optional BU objects MAY be specified in the PCReq message.
   As per [RFC5541], an OF object specifying a new objective function
   MAY also be specified.

   The format of the PCReq message (with [RFC5541] as a base) is updated
   as follows:

      <PCReq Message> ::= <Common Header>
                           [<svec-list>]
                           <request-list>
      where:
           <svec-list> ::= <SVEC>
                           [<OF>]
                           [<metric-list>]
                           [<svec-list>]

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

           <request> ::= <RP>
                         <END-POINTS>
                         [<LSPA>]
                         [<BANDWIDTH>]
                         [<bu-list>]
                         [<metric-list>]
                         [<OF>]
                         [<RRO>[<BANDWIDTH>]]
                         [<IRO>]
                         [<LOAD-BALANCING>]

      and where:
           <bu-list>::=<BU>[<bu-list>]
           <metric-list> ::= <METRIC>[<metric-list>]






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6.3.2.  The PCRep message

   The BU objects MAY be specified in the PCRep message, in case of an
   unsuccessful path computation, to indicate the bandwidth utilization
   as a reason for failure.  The OF object MAY be carried within a PCRep
   message to indicate the objective function used by the PCE during
   path computation.

   The format of the PCRep message (with [RFC5541] as a base) is updated
   as follows:

      <PCRep Message> ::= <Common Header>
                          [<svec-list>]
                          <response-list>

      where:

            <svec-list> ::= <SVEC>
                            [<OF>]
                            [<metric-list>]
                            [<svec-list>]

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

           <response> ::= <RP>
                          [<NO-PATH>]
                          [<attribute-list>]
                          [<path-list>]

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

           <path> ::= <ERO>
                      <attribute-list>

      and where:

           <attribute-list> ::= [<OF>]
                                [<LSPA>]
                                [<BANDWIDTH>]
                                [<bu-list>]
                                [<metric-list>]
                                [<IRO>]

           <bu-list>::=<BU>[<bu-list>]
           <metric-list> ::= <METRIC> [<metric-list>]






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7.  Other Considerations

7.1.  Reoptimization Consideration

   PCC can monitor the link bandwidth utilization of an LSP by
   monitoring changes in the bandwidth utilization parameters of one or
   more links on the path in the TED.  In case of drastic change, it MAY
   ask PCE for reoptimization as per [RFC5440].

7.2.  Inter-domain Consideration

   [RFC5441] describes the Backward-Recursive PCE-Based Computation
   (BRPC) procedure to compute end to end optimized inter-domain path by
   cooperating PCEs.  The new BU object defined in this document can be
   applied to end to end path computation, in similar manner as existing
   METRIC object.

   All domains should have the same understanding of the BU object for
   end-to-end inter-domain path computation to make sense.

7.2.1.  Inter-AS Link

   The IGP in each neighbor domain can advertise its inter-domain TE
   link capabilities, this has been described in [RFC5316] (ISIS) and
   [RFC5392] (OSPF).  The bandwidth related network performance link
   properties are described in [OSPF-TE-EXPRESS] and [ISIS-TE-EXPRESS],
   the same properties must be advertised using the mechanism described
   in [RFC5392] (OSPF) and [RFC5316] (ISIS).

7.3.  P2MP Consideration

   They are currently out of scope of this document.

7.4.  Stateful PCE

   [STATEFUL-PCE] specifies a set of extensions to PCEP to enable
   stateful control of MPLS-TE and GMPLS LSPs via PCEP and maintaining
   of these LSPs at the stateful PCE.  It further distinguishes between
   an active and a passive stateful PCE.  A passive stateful PCE uses
   LSP state information learned from PCCs to optimize path computations
   but does not actively update LSP state.  In contrast, an active
   stateful PCE utilizes the LSP delegation mechanism to let PCCs
   relinquish control over some LSPs to the PCE.

   The passive stateful PCE implementation MAY use the extension of
   PCReq and PCRep messages as defined in Section 6.3.1 and
   Section 6.3.2 to enable the use of BU object.




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   The additional objective functions defined in this document can also
   be used with stateful PCE.

7.4.1.  PCEP Message Extension

7.4.1.1.  The PCRpt message

   A Path Computation LSP State Report message (also referred to as
   PCRpt message) is a PCEP message sent by a PCC to a PCE to report the
   current state or delegate control of an LSP.  The PCRpt message is
   extended to support BU object.  This optional BU object can specify
   the upper limit that should not be crossed.

   As per [STATEFUL-PCE], the format of the PCRpt message is as follows:

      <PCRpt Message> ::= <Common Header>
                          <state-report-list>

      where:

           <state-report-list> ::= <state-report> [<state-report-list>]

           <state-report> ::= [<SRP>]
                          <LSP>
                          <path>

           <path> ::= <ERO><attribute-list>[<RRO>]

   Where <attribute-list> is extended as per Section 6.3.2 for BU
   object.

   Thus a BU object can be used to specify the upper limit set at the
   PCC at the time of LSP delegation to an active stateful PCE.

8.  IANA Considerations

   IANA assigns values to PCEP parameters in registries defined in
   [RFC5440].  IANA has made the following additional assignments.

8.1.  New PCEP Object

   IANA assigned a new object class in the registry of PCEP Objects as
   follows.

         Object Object     Name                  Reference
         Class  Type
         --------------------------------------------------
         TBD    1          BU                    [This I.D.]



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8.2.  BU Object

   IANA created a registry to manage the codespace of the Type field of
   the METRIC Object.

   Codespace of the T field (Metric Object)

         Type     Name                           Reference
         --------------------------------------------------
         1        LBU (Link Bandwidth            [This I.D.]
                  Utilization
         2        LRBU (Link Residual            [This I.D.]
                  Bandwidth Utilization

8.3.  Objective Functions

   Two new Objective Functions have been defined.  IANA has made the
   following allocations from the PCEP "Objective Function" sub-
   registry:

         Code     Name                           Reference
         Point
         --------------------------------------------------
         TBA      Maximum Under-Utilized         [This I.D.]
                  Path (MUP)
         TBA      Maximum Reserved               [This I.D.]
                  Under-Utilized Path (MRUP)

9.  Security Considerations

   This document defines a new BU object and OF codes which do not add
   any new security concerns beyond those discussed in [RFC5440].

10.  Manageability Considerations

10.1.  Control of Function and Policy

   The only configurable item is the support of the new constraints on a
   PCE which MAY be controlled by a policy module.  If the new
   constraints are not supported/allowed on a PCE, it MUST send a PCErr
   message as specified in Section 6.1.1.

10.2.  Information and Data Models

   [PCEP-MIB] describes the PCEP MIB, there are no new MIB Objects for
   this document.





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10.3.  Liveness Detection and Monitoring

   Mechanisms defined in this document do not imply any new liveness
   detection and monitoring requirements in addition to those already
   listed in [RFC5440].

10.4.  Verify Correct Operations

   Mechanisms defined in this document do not imply any new operation
   verification requirements in addition to those already listed in
   [RFC5440].

10.5.  Requirements On Other Protocols

   PCE requires the TED to be populated with the bandwidth utilization.
   This mechanism is described in [OSPF-TE-EXPRESS] or
   [ISIS-TE-EXPRESS].

10.6.  Impact On Network Operations

   Mechanisms defined in this document do not have any impact on network
   operations in addition to those already listed in [RFC5440].

11.  Acknowledgments

   We would like to thank Alia Atlas, John E Drake and David Ward for
   their useful comments and suggestions.

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.

12.2.  Informative References

   [RFC3630]  Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering
              (TE) Extensions to OSPF Version 2", RFC 3630, September
              2003.

   [RFC3784]  Smit, H. and T. Li, "Intermediate System to Intermediate
              System (IS-IS) Extensions for Traffic Engineering (TE)",
              RFC 3784, June 2004.

   [RFC5316]  Chen, M., Zhang, R., and X. Duan, "ISIS Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS
              Traffic Engineering", RFC 5316, December 2008.



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   [RFC5392]  Chen, M., Zhang, R., and X. Duan, "OSPF Extensions in
              Support of Inter-Autonomous System (AS) MPLS and GMPLS
              Traffic Engineering", RFC 5392, January 2009.

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

   [RFC5441]  Vasseur, JP., Zhang, R., Bitar, N., and JL. Le Roux, "A
              Backward-Recursive PCE-Based Computation (BRPC) Procedure
              to Compute Shortest Constrained Inter-Domain Traffic
              Engineering Label Switched Paths", RFC 5441, April 2009.

   [RFC5541]  Le Roux, JL., Vasseur, JP., and Y. Lee, "Encoding of
              Objective Functions in the Path Computation Element
              Communication Protocol (PCEP)", RFC 5541, June 2009.

   [OSPF-TE-EXPRESS]
              Giacalone, S., Ward, D., Drake, J., Atlas, A., and S.
              Previdi, "OSPF Traffic Engineering (TE) Metric
              Extensions", draft-ietf-ospf-te-metric-extensions-05 (work
              in progress), December 2013.

   [ISIS-TE-EXPRESS]
              Previdi, S., Giacalone, S., Ward, D., Drake, J., Atlas,
              A., Filsfils, C., and W. Wu, "IS-IS Traffic Engineering
              (TE) Metric Extensions", draft-ietf-isis-te-metric-
              extensions-03 (work in progress), April 2014.

   [PCEP-MIB]
              Koushik, K., Emile, S., Zhao, Q., King, D., and J.
              Hardwick, "Path Computation Element Protocol (PCEP)
              Management Information Base", draft-ietf-pce-pcep-mib-08
              (work in progress), April 2014.

   [STATEFUL-PCE]
              Crabbe, E., Medved, J., Minei, I., and R. Varga, "PCEP
              Extensions for Stateful PCE", draft-ietf-pce-stateful-
              pce-08 (work in progress), February 2014.

   [PCE-SERVICE-AWARE]
              Dhody, D., Manral, V., Ali, Z., Swallow, G., and K.
              Kumaki, "Extensions to the Path Computation Element
              Communication Protocol (PCEP) to compute service aware
              Label Switched Path (LSP).", draft-ietf-pce-pcep-service-
              aware-04 (work in progress), March 2014.





Wu, et al.              Expires December 26, 2014              [Page 14]


Internet-Draft           TE Link BW Utilization                June 2014


Appendix A.  Contributor Addresses

   Udayasree Palle
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   INDIA
   EMail: udayasree.palle@huawei.com

   Avantika
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   INDIA
   EMail: avantika.sushilkumar@huawei.com

   Zafar Ali
   Cisco Systems

   EMail: zali@cisco.com

Authors' Addresses

   Qin Wu
   Huawei Technologies
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   EMail: sunseawq@huawei.com


   Dhruv Dhody
   Huawei Technologies
   Leela Palace
   Bangalore, Karnataka  560008
   INDIA

   EMail: dhruv.ietf@gmail.com


   Stefano Previdi
   Cisco Systems, Inc
   Via Del Serafico 200
   Rome  00191
   IT

   EMail: sprevidi@cisco.com



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