[Docs] [txt|pdf|xml|html] [Tracker] [Email] [Nits]

Versions: 00 01 02 03

Network Working Group                                              C. Li
Internet-Draft                                                   M. Chen
Intended status: Experimental                                    J. Dong
Expires: December 22, 2018                                         Z. Li
                                                                D. Dhody
                                                     Huawei Technologies
                                                           June 20, 2018


                        PCE Controlled ID Space
                  draft-li-pce-controlled-id-space-00

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 Stateful PCE extensions allow stateful control of Multiprotocol
   Label Switching (MPLS) Traffic Engineering (TE) Label Switched Paths
   (LSPs) using PCEP.  Furthermore, PCEP can be used for computing paths
   in SR networks.

   Stateful PCE provide active control of MPLS-TE LSPs via PCEP, for a
   model where the PCC delegates control over one or more locally
   configured LSPs to the PCE.  Further, stateful PCE could also create
   and delete PCE-initiated LSPs itself.  A PCE-based central controller
   (PCECC) simplify the processing of a distributed control plane by
   blending it with elements of Software-Defined Networking (SDN) and
   without necessarily completely replacing it.

   In some use cases, such as PCECC, Binding Segment Identifier (SID),
   SR Path Identification, there is a requirement for a stateful PCE to
   make allocation of labels, SID, Path-ID respectively.  These use
   cases require for the PCE to be aware of the various identifier space
   from which to make allocations on behalf of PCC.  This documents
   specify a mechanism for a PCC to inform the PCE of the identifier
   space under its control via PCEP.  The identifier could be MPLS
   label, SID, Path ID or another future identifier to be allocated by a
   PCE.

Requirements Language

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




Li, et al.              Expires December 22, 2018               [Page 1]


Internet-Draft           PCE Controlled ID Space               June 2018


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 https://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 December 22, 2018.

Copyright Notice

   Copyright (c) 2018 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
   (https://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Use cases . . . . . . . . . . . . . . . . . . . . . . . . . .   4
     3.1.  PCE-based Central Control . . . . . . . . . . . . . . . .   4
     3.2.  Binding SID Allocation  . . . . . . . . . . . . . . . . .   5
     3.3.  Path ID Allocation  . . . . . . . . . . . . . . . . . . .   5
   4.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   5.  Objects . . . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  Open Object . . . . . . . . . . . . . . . . . . . . . . .   7
       5.1.1.  LABEL-CONTROL-SPACE TLV . . . . . . . . . . . . . . .   7
       5.1.2.  SRv6-PATH-ID-CONTROL-SPACE TLV  . . . . . . . . . . .   8
   6.  Other Considerations  . . . . . . . . . . . . . . . . . . . .   9
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  10
   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  10



Li, et al.              Expires December 22, 2018               [Page 2]


Internet-Draft           PCE Controlled ID Space               June 2018


   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  10
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  10
     10.1.  Normative References . . . . . . . . . . . . . . . . . .  10
     10.2.  Informative References . . . . . . . . . . . . . . . . .  11
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  12

1.  Introduction

   [RFC5440] defines the stateless Path Computation Element
   communication Protocol (PCEP) for Path Computation Elements (PCEs) to
   perform path computations in response to Path Computation Clients
   (PCCs) requests.  For supporting stateful operations, [RFC8231]
   specifies a set of extensions to PCEP to enable stateful control of
   LSPs within and across PCEP sessions in compliance with [RFC4657].
   Furthermore, [RFC8281] describes the setup, maintenance, and teardown
   of PCE-initiated LSPs under the stateful PCE model, without the need
   for local configuration on the PCC, thus allowing for a dynamic
   network that is centrally controlled and deployed.

   [RFC8283] introduces the architecture for PCE as a central
   controller, it examines the motivations and applicability for PCEP as
   a control protocol in this environment, and introduces the
   implications for the protocol.  Also,
   [I-D.zhao-pce-pcep-extension-for-pce-controller] specifies the
   procedures and PCEP protocol extensions for using the PCE as the
   central controller, where LSPs are calculated/setup/initiated and
   label forwarding entries are downloaded through extending PCEP.
   However, the document assumes that label range to be used by a PCE is
   known and set on both PCEP peers.  This extension adds the capability
   to advertise the range via a PCEP extension.

   Similarly, [I-D.zhao-pce-pcep-extension-pce-controller-sr] specifies
   the procedures and PCEP protocol extensions when a PCE-based
   controller is also responsible for configuring the forwarding actions
   on the routers (SR SID distribution in this case), in addition to
   computing the paths for packet flows in a segment routing network and
   telling the edge routers what instructions to attach to packets as
   they enter the network.  However, the document assumes that label
   range to be used by a PCE is known and set on both PCEP peers.  This
   extension adds the capability to advertise the range (from SRGB or
   SRLB of the node) via a PCEP extension.

   [I-D.li-pce-sr-path-segment] defines a procedure for path ID in PCEP
   for SR by defining the PATH-ID TLV.  The path ID can be a path
   segment in SR-MPLS [I-D.cheng-spring-mpls-path-segment], or a path ID
   in SRv6 [I-D.li-spring-passive-pm-for-srv6-np], or other IDs that can
   identify an SR path.  This document specify the extension to support
   advertisement of the various ID space to the PCE to control.



Li, et al.              Expires December 22, 2018               [Page 3]


Internet-Draft           PCE Controlled ID Space               June 2018


   The usecase are described in Section 3.  The ID space range
   information can be advertised via the TLVs in the Open message.  The
   detailed procedures will be described in Section 4, and the objects'
   format will be introduced in Section 5.

2.  Terminology

   This memo makes use of the terms defined in [RFC5440], [RFC8231],
   [RFC8283] and [I-D.ietf-spring-segment-routing].

3.  Use cases

3.1.  PCE-based Central Control

   A PCE-based central controller (PCECC) can simplify the processing of
   a distributed control plane by blending it with elements of SDN and
   without necessarily completely replacing it.  Thus, the LSP can be
   calculated/setup/initiated and the label forwarding entries can also
   be downloaded through a centralized PCE server to each network
   devices along the path while leveraging the existing PCE technologies
   as much as possible.

   [I-D.zhao-pce-pcep-extension-for-pce-controller] describe a mode
   where LSPs are provisioned as explicit label instructions at each hop
   on the end-to-end path.  Each router along the path must be told what
   label forwarding instructions to program and what resources to
   reserve.  The controller uses PCEP to communicate with each router
   along the path of the end-to-end LSP.  For this to work, the PCE-
   based controller will take responsibility for managing some part of
   the MPLS label space for each of the routers that it controls as
   described in section 3.1.2. of [RFC8283].  A mechanism for a PCC to
   inform the PCE of such a label space to control is needed within
   PCEP.

   [I-D.ietf-pce-segment-routing] specifies extensions to PCEP that
   allow a stateful PCE to compute, update or initiate SR-TE paths.
   [I-D.zhao-pce-pcep-extension-pce-controller-sr] describes the
   mechanism for PCECC to allocate and provision the node/prefix/
   adjacency label (SID) via PCEP.  To make such allocation PCE needs to
   be aware of the label space from Segment Routing Global Block (SRGB)
   or Segment Routing Local Block (SRLB)
   [I-D.ietf-spring-segment-routing] of the node that it controls.  A
   mechanism for a PCC to inform the PCE of such a label space to
   control is needed within PCEP.  The full SRGB/SRLB of a node could be
   learned via existing IGP or BGP-LS mechanism.






Li, et al.              Expires December 22, 2018               [Page 4]


Internet-Draft           PCE Controlled ID Space               June 2018


3.2.  Binding SID Allocation

   The headend of an SR Policy binds a binding SID to its policy
   [I-D.ietf-spring-segment-routing].  The instantiation of which may
   involve a list of SIDs.  Currently binding SID are allocated by the
   node, but there is an inherent advantage in the binding SID to be
   allocated by a PCE to allow SR policies to be dynamically created,
   updated according to the network status and operations.  Therefore, a
   PCE needs to obtain the authority and control to allocate binding SID
   actively from the PCC's label space as described in above use case.

3.3.  Path ID Allocation

   Path identification is needed for several use cases such as
   performance measurement in Segment Routing (SR) network.  For
   identifying an SR path, [I-D.cheng-spring-mpls-path-segment]
   introduces a new segment that is referred to as Path Segment, and
   [I-D.li-spring-passive-pm-for-srv6-np] introduces the path ID in
   SRv6.

   [I-D.li-pce-sr-path-segment] defines a procedure for path ID in PCEP
   for SR.  It describes a mode in which PCE could allocate path ID and
   inform the ingress and egress PCC.  To make such an allocation a PCE
   needs to be aware of the path ID space under its control.  A
   mechanism for a PCC to inform the PCE of such a path ID space is
   needed within PCEP.

4.  Overview

   During PCEP Initialization Phase, Open messages are exchanged between
   PCCs and PCEs.  The OPEN object may also contain a set of TLVs used
   to convey capabilities in the Open message.  The ID could be a MPLS
   label, SRv6 path ID or any other future ID space for PCE to allocate.
   A PCC can include a corresponding ID-CONTROL-SPACE TLVs, in the OPEN
   Object to inform the corresponding ID space information that it wants
   the PCE to control.  This TLV MUST NOT be included by the PCE and
   MUST be ignored on receipt by a PCC.  This is an optional TLV, the
   PCE could be aware of the ID space from some other means outside of
   PCEP.

   For delegating multiple types of ID space, multiple TLVs
   corresponding to each ID type MUST be included in a Open message.
   Each TLV (corresponding to each ID type) SHOULD be included only once
   in a Open Message.  On receipt, only the first instance is processed
   and others MUST be ignored.  The ID type can be MPLS label, SRv6 path
   ID [I-D.li-spring-passive-pm-for-srv6-np] or other ID.  The following
   ID-CONTROL-SPACE TLVs are defined in this document -




Li, et al.              Expires December 22, 2018               [Page 5]


Internet-Draft           PCE Controlled ID Space               June 2018


   o  LABEL-CONTROL-SPACE - for MPLS Labels (including for SR-MPLS)

   o  SRv6-PATH-ID-CONTROL-SPACE - for SRv6 Path ID

   The procedure of ID space control to PCE is shown below:

              +-+-+                                     +-+-+
              |PCC|                                     |PCE|
              +-+-+                                     +-+-+
                |                                         |
                | Open msg (LABEL-CONTROL-SPACE, and/or   |
                |           SRv6-PATH-ID-CONTROL-SPACE)   |
                |--------                                 |
                |        \                     Open msg   |
                |         \  -----------------------------|
                |          \/                             |
                |          /\                             |
                |         /  ---------------------------->|
                |        /                                |
                |<------                       Keepalive  |
                |             ----------------------------|
                |Keepalive   /                            |
                |--------   /                             |
                |        \/                               |
                |        /\                               |
                |<------   ------------------------------>|
                |                                         |


                     Figure 1: ID space control to PCE

   If the ID space control procedure is successful, the PCE will return
   a KeepAlive message to the PCC.  If there is any error in processing
   the corresponding TLV, an Error (PCErr) message will be sent to the
   PCC with Error-Type=1 (PCEP session establishment failure) and Error-
   value=TBD (ID space control failure).

   After this process, a stateful PCE can learn the PCE controlled ID
   spaces of a node (PCC) under its control.  A PCE can then allocate
   IDs within the control ID space.  For example, a PCE can actively
   allocate labels and download forwarding instructions for the PCECC
   LSP as described in [I-D.zhao-pce-pcep-extension-for-pce-controller].
   A PCE can also allocate labels from SRGB/SRLB for PCECC-SR
   [I-D.zhao-pce-pcep-extension-pce-controller-sr], binding segments,
   and path segments [I-D.cheng-spring-mpls-path-segment].  The full
   SRGB/SRLB of a node could be learned via existing IGP or BGP-LS
   mechanism.  Similarly a PCE can allocate SRv6 Path ID




Li, et al.              Expires December 22, 2018               [Page 6]


Internet-Draft           PCE Controlled ID Space               June 2018


   [I-D.li-spring-passive-pm-for-srv6-np] according to the SRv6 Path ID
   space under its control.

5.  Objects

5.1.  Open Object

   For advertising the PCE controlled ID space to a PCE, this document
   defines several TLVs within the Open object.

5.1.1.  LABEL-CONTROL-SPACE TLV

   For a PCC to inform the label space under the PCE control, this
   document defines a new LABEL-CONTROL-SPACE TLV.

   The LABEL-CONTROL-SPACE TLV is an optional TLV for use in the OPEN
   object, and its format is shown in the following figure:

      0                   1                   2                   3
      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |            Type=TBA           |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Flags                           |A|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    Start (1)                  |   Reserved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    Range (1)                  |   Reserved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              ...                              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              ...                              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    Start (n)                  |   Reserved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                    Range (n)                  |   Reserved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                     Figure 2: LABEL-CONTROL-SPACE TLV

   The type (16 bits) of the TLV is TBA.  The length field (16 bits) and
   has a variable value.

   Flags (32 bits): Following flags are currently defined

   o  A-flag: All space flag, set when all the label space is delegated
      to a PCE.  When A-flag is set, the pair of Start and End SHOULD



Li, et al.              Expires December 22, 2018               [Page 7]


Internet-Draft           PCE Controlled ID Space               June 2018


      NOT appear unless the PCC needs to notify the entire ID space to a
      PCE.

   The unassigned bits of Flags field MUST be set to 0 on transmission
   and MUST be ignored on receipt.

   Start(i) (24 bits): indicates the beginning of the label block i.

   Range(i) (24 bits): indicates the range of the label block i.

   Reserved: SHOULD be set to 0 on transmission and MUST be ignored on
   reception.

   The number of label blocks can be calculated according to value of
   the length field in the TLV.

   A stateful PCE can actively allocate labels and download forwarding
   instructions for the PCECC LSP as described in
   [I-D.zhao-pce-pcep-extension-for-pce-controller].  A PCE can also
   allocate labels from SRGB/SRLB for PCECC-SR
   [I-D.zhao-pce-pcep-extension-pce-controller-sr] and binding segments
   can be selected for the PCE controlled space.  Also, Path segment
   [I-D.cheng-spring-mpls-path-segment] can be allocated by a stateful
   PCE in a similar same way as described in [I-D.li-pce-sr-path-
   segment].

5.1.2.  SRv6-PATH-ID-CONTROL-SPACE TLV

   For a PCC to inform the SRv6 path ID space under the PCE control,
   this document defines a new SRv6-PATH-ID-CONTROL-SPACE TLV.

   The SRv6-PATH-ID-CONTROL-SPACE TLV is an optional TLV for use in the
   OPEN object, and its format is shown in the following figure:


















Li, et al.              Expires December 22, 2018               [Page 8]


Internet-Draft           PCE Controlled ID Space               June 2018


      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=TBA           |            Length             |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                             Flags                           |A|
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Start (1)                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Range (1)                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              ...                              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                              ...                              |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Start (n)                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           Range (n)                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+



                 Figure 3: SRv6-PATH-ID-CONTROL-SPACE TLV

   The type (16 bits) of the TLV is TBA.  The length field (16 bits) and
   has a variable value.

   Flags (32 bits): is of same format as LABEL-CONTROL-SPACE TLV.  Any
   bits assigned in the LABEL-CONTROL-SPACE TLV are also applicable for
   this.

   Start(i) (32 bits): indicates the beginning of the SRv6 Path ID block
   i.

   Range(i) (32 bits): indicates the range of the SRv6 Path ID block i.

   The number of Path ID blocks can be calculated according to the
   length field in the TLV.  Given the controlled ID spaces, a stateful
   PCE can actively allocate path IDs to SRv6 paths from the controlled
   ID spaces as described in [I-D.li-pce-sr-path-segment].

6.  Other Considerations

   In case of multiple PCEs, a PCC MAY decide to give control over
   different ID space to each instance of the PCE.  In case a PCC
   includes the same ID space to multiple PCEs, the PCE SHOULD use
   synchronization mechanism (such as [I-D.litkowski-pce-state-sync]) to
   avoid allocating the same ID.



Li, et al.              Expires December 22, 2018               [Page 9]


Internet-Draft           PCE Controlled ID Space               June 2018


7.  IANA Considerations

   TBA.

8.  Security Considerations

   TBA.

9.  Acknowledgements

   TBA.

10.  References

10.1.  Normative References

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

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

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

   [RFC8231]  Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for Stateful PCE", RFC 8231,
              DOI 10.17487/RFC8231, September 2017,
              <https://www.rfc-editor.org/info/rfc8231>.

   [RFC8281]  Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path
              Computation Element Communication Protocol (PCEP)
              Extensions for PCE-Initiated LSP Setup in a Stateful PCE
              Model", RFC 8281, DOI 10.17487/RFC8281, December 2017,
              <https://www.rfc-editor.org/info/rfc8281>.

   [RFC8283]  Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An
              Architecture for Use of PCE and the PCE Communication
              Protocol (PCEP) in a Network with Central Control",
              RFC 8283, DOI 10.17487/RFC8283, December 2017,
              <https://www.rfc-editor.org/info/rfc8283>.




Li, et al.              Expires December 22, 2018              [Page 10]


Internet-Draft           PCE Controlled ID Space               June 2018


10.2.  Informative References

   [RFC4657]  Ash, J., Ed. and J. Le Roux, Ed., "Path Computation
              Element (PCE) Communication Protocol Generic
              Requirements", RFC 4657, DOI 10.17487/RFC4657, September
              2006, <https://www.rfc-editor.org/info/rfc4657>.

   [I-D.ietf-pce-segment-routing]
              Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W.,
              and J. Hardwick, "PCEP Extensions for Segment Routing",
              draft-ietf-pce-segment-routing-11 (work in progress),
              November 2017.

   [I-D.ietf-spring-segment-routing]
              Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B.,
              Litkowski, S., and R. Shakir, "Segment Routing
              Architecture", draft-ietf-spring-segment-routing-15 (work
              in progress), January 2018.

   [I-D.zhao-pce-pcep-extension-for-pce-controller]
              Zhao, Q., Li, Z., Dhody, D., Karunanithi, S., Farrel, A.,
              and C. Zhou, "PCEP Procedures and Protocol Extensions for
              Using PCE as a Central Controller (PCECC) of LSPs", draft-
              zhao-pce-pcep-extension-for-pce-controller-08 (work in
              progress), June 2018.

   [I-D.zhao-pce-pcep-extension-pce-controller-sr]
              Zhao, Q., Li, Z., Dhody, D., Karunanithi, S., Farrel, A.,
              and C. Zhou, "PCEP Procedures and Protocol Extensions for
              Using PCE as a Central Controller (PCECC) of SR-LSPs",
              draft-zhao-pce-pcep-extension-pce-controller-sr-03 (work
              in progress), June 2018.

   [I-D.litkowski-pce-state-sync]
              Litkowski, S., Sivabalan, S., and D. Dhody, "Inter
              Stateful Path Computation Element communication
              procedures", draft-litkowski-pce-state-sync-03 (work in
              progress), April 2018.

   [I-D.cheng-spring-mpls-path-segment]
              Cheng, W., Wang, L., Li, H., Chen, M., Zigler, R., and S.
              Zhan, "Path Segment in MPLS Based Sement Routing Network",
              draft-cheng-spring-mpls-path-segment-01 (work in
              progress), March 2018.







Li, et al.              Expires December 22, 2018              [Page 11]


Internet-Draft           PCE Controlled ID Space               June 2018


   [I-D.li-spring-passive-pm-for-srv6-np]
              Li, C. and M. Chen, "Passive Performance Measurement for
              SRv6 Network Programming", draft-li-spring-passive-pm-for-
              srv6-np-00 (work in progress), March 2018.

Authors' Addresses

   Cheng Li
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   EMail: chengli13@huawei.com


   Mach(Guoyi) Chen
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   EMail: Mach.chen@huawei.com


   Jie Dong
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   EMail: jie.dong@huawei.com


   Zhenbin Li
   Huawei Technologies
   Huawei Campus, No. 156 Beiqing Rd.
   Beijing  100095
   China

   EMail: lizhenbin@huawei.com










Li, et al.              Expires December 22, 2018              [Page 12]


Internet-Draft           PCE Controlled ID Space               June 2018


   Dhruv Dhody
   Huawei Technologies
   Divyashree Techno Park, Whitefield
   Bangalore, Karnataka  560066
   India

   EMail: dhruv.ietf@gmail.com












































Li, et al.              Expires December 22, 2018              [Page 13]


Html markup produced by rfcmarkup 1.129c, available from https://tools.ietf.org/tools/rfcmarkup/