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Versions: (draft-ali-pce-remote-initiated-gmpls-lsp) 00 01 02 03 04 05 06 draft-ietf-pce-pcep-stateful-pce-gmpls

PCE Working Group                                                 Z. Ali
Internet-Draft                                              S. Sivabalan
Intended status: Standards Track                             C. Filsfils
Expires: August 27, 2019                                   Cisco Systems
                                                                R. Varga
                                                   Pantheon Technologies
                                                                V. Lopez
                                                     O. Gonzalez de Dios
                                                              Telefonica
                                                                H. Zheng
                                                                X. Zhang
                                                     Huawei Technologies
                                                       February 23, 2019


 Path Computation Element Communication Protocol (PCEP) Extensions for
                    remote-initiated GMPLS LSP Setup
            draft-ietf-pce-remote-initiated-gmpls-lsp-06.txt

Abstract

   [RFC8281] specifies procedures that can be used for creation and
   deletion of PCE-initiated LSPs in the active stateful PCE model.
   However, this specification focuses on MPLS networks, and does not
   cover remote instantiation of paths in GMPLS-controlled networks.
   This document complements [RFC8281] by addressing the requirements
   for remote-initiated GMPLS LSPs.

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].

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."



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   This Internet-Draft will expire on August 27, 2019.

Copyright Notice

   Copyright (c) 2019 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  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements for Remote-Initiated GMPLS LSPs  . . . . . . . .   3
   3.  PCEP Extensions for Remote-Initiated GMPLS LSPs . . . . . . .   4
   3.1.  Generalized Endpoint in LSP Initiate Message  . . . . . . .   4
   3.2.  GENERALIZED-BANDWIDTH object in LSP Initiate Message  . . .   4
   3.3.  Protection Attributes in LSP Initiate Message . . . . . . .   5
   3.4.  ERO in LSP Initiate Object  . . . . . . . . . . . . . . . .   5
   3.4.1.  ERO with explicit label control . . . . . . . . . . . . .   5
   3.4.2.  ERO with Path Keys  . . . . . . . . . . . . . . . . . . .   6
   3.4.3.  Switch Layer Object . . . . . . . . . . . . . . . . . . .   6
   3.5.  LSP delegation and cleanup  . . . . . . . . . . . . . . . .   6
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   5.1.  PCEP-Error Object . . . . . . . . . . . . . . . . . . . . .   7
   6.  Contributors  . . . . . . . . . . . . . . . . . . . . . . . .   7
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   7
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
   8.1.  Normative References  . . . . . . . . . . . . . . . . . . .   7
   8.2.  Informational References  . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9

1.  Introduction

   The Path Computation Element communication Protocol (PCEP) provides
   mechanisms for Path Computation Elements (PCEs) to perform route
   computations in response to Path Computation Clients (PCCs) requests.
   PCEP Extensions for PCE-initiated LSP Setup in a Stateful PCE Model
   draft [RFC8231] describes a set of extensions to PCEP to enable
   active control of MPLS-TE and GMPLS network.



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   [RFC8281] describes the setup and teardown of PCE-initiated LSPs
   under the active stateful PCE model, without the need for local
   configuration on the PCC.  This enables realization of a dynamic
   network that is centrally controlled and deployed.  However, this
   specification is focused on MPLS networks, and does not cover the
   GMPLS networks (e.g., WSON, OTN, SONET/ SDH, etc. technologies).
   This document complements [RFC8281] by addressing the requirements
   for remote-initiated GMPLS LSPs.  These requirements are covered in
   Section 2 of this draft.  The PCEP extensions for remote initiated
   GMPLS LSPs are specified in Section 3.

2.  Requirements for Remote-Initiated GMPLS LSPs

   [RFC8281] specifies procedures that can be used for creation and
   deletion of PCE-initiated LSPs under the active stateful PCE model.
   However, this specification does not address GMPLS requirements
   outlined in the following:

   o  GMPLS support multiple switching capabilities on per TE link
      basis.  GMPLS LSP creation requires knowledge of LSP switching
      capability (e.g., TDM, L2SC, OTN-TDM, LSC, etc.) to be used
      [RFC3471] , [RFC3473] .

   o  GMPLS LSP creation requires knowledge of the encoding type (e.g.,
      lambda photonic, Ethernet, SONET/ SDH, G709 OTN, etc.) to be used
      by the LSP [RFC3471] , [RFC3473].

   o  GMPLS LSP creation requires information of the generalized payload
      (G-PID) to be carried by the LSP [RFC3471] , [RFC3473].

   o  GMPLS LSP creation requires specification of data flow specific
      traffic parameters (also known as Tspec), which are technology
      specific.

   o  GMPLS also specifics support for asymmetric bandwidth requests
      [RFC6387] .

   o  GMPLS extends the addressing to include unnumbered interface
      identifiers, as defined in [RFC3477] .

   o  In some technologies path calculation is tightly coupled with
      label selection along the route.  For example, path calculation in
      a WDM network may include lambda continuity and/ or lambda
      feasibility constraints and hence a path computed by the PCE is
      associated with a specific lambda (label).  Hence, in such
      networks, the label information needs to be provided to a PCC in
      order for a PCE to initiate GMPLS LSPs under the active stateful
      PCE model.  I.e., explicit label control may be required.



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   o  GMPLS specifics protection context for the LSP, as defined in
      [RFC4872] , [RFC4873].

3.  PCEP Extensions for Remote-Initiated GMPLS LSPs

   LSP initiate (PCInitiate) message defined in [RFC8281] needs to be
   extended to include GMPLS specific PCEP objects as follows:

3.1.  Generalized Endpoint in LSP Initiate Message

   This document does not modify the usage of END-POINTS object for PCE
   initiated LSPs as specified in [RFC8281] . It augments the usage as
   specified below.

   END-POINTS object has been extended by
   [I-D.ietf-pce-gmpls-pcep-extensions] to include a new object type
   called "Generalized Endpoint".  PCInitiate message sent by a PCE to a
   PCC to trigger a GMPLS LSP instantiation SHOULD include the END-
   POINTS with Generalized Endpoint object type.  Furthermore, the END-
   POINTS object MUST contain "label request" TLV.  The label request
   TLV is used to specify the switching type, encoding type and GPID of
   the LSP being instantiated by the PCE.

   If the END-POINTS Object of type Generalized Endpoint is missing the
   label request TLV, the PCC MUST send a PCErr message with Error-
   type=6 (Mandatory Object missing) and Error-value= TBA (label request
   TLV missing).

   If the PCC does not support the END-POINTS Object of type Generalized
   Endpoint, the PCC MUST send a PCErr message with Error-type = 3
   (Unknown Object), Error-value = 2(unknown object type).

   The unnumbered endpoint TLV can be used to specify unnumbered
   endpoint addresses for the LSP being instantiated by the PCE.  The
   END-POINTS MAY contain other TLVs defined in
   [I-D.ietf-pce-gmpls-pcep-extensions].

3.2.  GENERALIZED-BANDWIDTH object in LSP Initiate Message

   LSP initiate message defined in [RFC8281] can optionally include the
   BANDWIDTH object.  However, the following possibilities cannot be
   represented in the BANDWIDTH object:

   o  Asymmetric bandwidth (different bandwidth in forward and reverse
      direction), as described in [RFC6387] .

   o  Technology specific GMPLS parameters (e.g., Tspec for SDH/SONET,
      G.709, ATM, MEF, etc.) are not supported.



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   GENERALIZED-BANDWIDTH object has been defined in
   [I-D.ietf-pce-gmpls-pcep-extensions] to address the above-mentioned
   limitation of the BANDWIDTH object.

   This document specifies the use of GENERALIZED-BANDWIDTH object in
   PCInitiate message.  Specifically, GENERALIZED-BANDWIDTHobject MAY be
   included in the PCInitiate message.  The GENERALIZED-BANDWIDTH object
   in PCInitiate message is used to specify technology specific Tspec
   and asymmetrical bandwidth values for the LSP being instantiated by
   the PCE.

3.3.  Protection Attributes in LSP Initiate Message

   This document does not modify the usage of LSPA object for PCE
   initiated LSPs as specified in [RFC8281] . It augments the usage of
   LSPA object in LSP Initiate Message to carry the end-to-end
   protection context this also includes the protection state
   information.

   The LSP Protection Information TLV of LSPA in the PCInitiate message
   can be used to specify protection attributes of the LSP being
   instantiated by the PCE.

3.4.  ERO in LSP Initiate Object

   This document does not modify the usage of ERO object for PCE
   initiated LSPs as specified in [RFC8281].  It augments the usage as
   specified in the following sections.

3.4.1.  ERO with explicit label control

   As mentioned earlier, there are technologies and scenarios where
   active stateful PCE requires explicit label control in order to
   instantiate an LSP.

   Explicit label control (ELC) is a procedure supported by RSVP-TE,
   where the outgoing label(s) is (are) encoded in the ERO.
   [I-D.ietf-pce-gmpls-pcep-extensions] extends the ERO object of PCEP
   to include explicit label control.  The ELC procedure enables the PCE
   to provide such label(s) directly in the path ERO.

   The extended ERO object in PCInitiate message can be used to specify
   label along with ERO to PCC for the LSP being instantiated by the
   active stateful PCE.







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3.4.2.  ERO with Path Keys

   There are many scenarios in packet and optical networks where the
   route information of an LSP may not be provided to the PCC for
   confidentiality reasons.  A multi-domain or multi-layer network is an
   example of such networks.  Similarly, a GMPLS User- Network Interface
   (UNI) [RFC4208] is also an example of such networks.

   In such scenarios, ERO containing the entire route cannot be provided
   to PCC (by PCE).  Instead, PCE provides an ERO with Path Keys to the
   PCC.  For example, in the case UNI interface between the router and
   the optical nodes, the ERO in the LSP Initiate Message may be
   constructed as follows:

   o  The first hop is a strict hop that provides the egress interface
      information at PCC.  This interface information is used to get to
      a network node that can extend the rest of the ERO.  (Please note
      that in the cases where the network node is not directly connected
      with the PCC, this part of ERO may consist of multiple hops and
      may be loose).

   o  The following(s) hop in the ERO may provide the network node with
      the path key [RFC5520] that can be resolved to get the contents of
      the route towards the destination.

   o  There may be further hops but these hops may also be encoded with
      the path keys (if needed).

   This document does not change encoding or processing roles for the
   path keys, which are defined in [RFC5520].

3.4.3.  Switch Layer Object

   [I-D.ietf-pce-inter-layer-ext] specifies the SWITCH-LAYER object
   which defines and specifies the switching layer (or layers) in which
   a path MUST or MUST NOT be established.  A switching layer is
   expressed as a switching type and encoding type.
   [I-D.ietf-pce-gmpls-pcep-extensions], which defines the GMPLS
   extensions for PCEP, suggests using the SWITCH-LAYER object.  Thus,
   SWITCH-LAYER object can be used in the PCInitiate message to specify
   the switching layer (or layers) of the LSP being remotely initiated.

3.5.  LSP delegation and cleanup

   LSP delegation and cleanup procedure specified in
   [I-D.ietf-pce-gmpls-pcep-extensions] are equally applicable to GMPLS
   LSPs and this document does not modify the associated usage.




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4.  Security Considerations

   The security considerations described in [RFC8281] apply to the
   extensions described in this document.

5.  IANA Considerations

5.1.  PCEP-Error Object

   This document defines the following new Error-Value:


 Error-type              Error Value                 Reference
  6       Error-value = TBA: Label Request TLV Missing       this document


6.  Contributors

   Sajal Agarwal
   Cisco Systems
   Email: sajaagar@cisco.com

7.  Acknowledgements

   The authors would like to thank George Swallow and Jan Medved for
   their comments.

8.  References

8.1.  Normative References

   [I-D.ietf-pce-gmpls-pcep-extensions]
              Margaria, C., Dios, O., and F. Zhang, "PCEP extensions for
              GMPLS", draft-ietf-pce-gmpls-pcep-extensions-13 (work in
              progress), January 2019.

   [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>.






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   [RFC5623]  Oki, E., Takeda, T., Le Roux, JL., and A. Farrel,
              "Framework for PCE-Based Inter-Layer MPLS and GMPLS
              Traffic Engineering", RFC 5623, DOI 10.17487/RFC5623,
              September 2009, <https://www.rfc-editor.org/info/rfc5623>.

   [RFC6107]  Shiomoto, K., Ed. and A. Farrel, Ed., "Procedures for
              Dynamically Signaled Hierarchical Label Switched Paths",
              RFC 6107, DOI 10.17487/RFC6107, February 2011,
              <https://www.rfc-editor.org/info/rfc6107>.

   [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>.

8.2.  Informational References

   [I-D.ietf-pce-inter-layer-ext]
              Oki, E., Takeda, T., Farrel, A., and F. Zhang, "Extensions
              to the Path Computation Element communication Protocol
              (PCEP) for Inter-Layer MPLS and GMPLS Traffic
              Engineering", draft-ietf-pce-inter-layer-ext-12 (work in
              progress), January 2017.

   [RFC3471]  Berger, L., Ed., "Generalized Multi-Protocol Label
              Switching (GMPLS) Signaling Functional Description",
              RFC 3471, DOI 10.17487/RFC3471, January 2003,
              <https://www.rfc-editor.org/info/rfc3471>.

   [RFC3473]  Berger, L., Ed., "Generalized Multi-Protocol Label
              Switching (GMPLS) Signaling Resource ReserVation Protocol-
              Traffic Engineering (RSVP-TE) Extensions", RFC 3473,
              DOI 10.17487/RFC3473, January 2003,
              <https://www.rfc-editor.org/info/rfc3473>.

   [RFC3477]  Kompella, K. and Y. Rekhter, "Signalling Unnumbered Links
              in Resource ReSerVation Protocol - Traffic Engineering
              (RSVP-TE)", RFC 3477, DOI 10.17487/RFC3477, January 2003,
              <https://www.rfc-editor.org/info/rfc3477>.





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   [RFC4208]  Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
              "Generalized Multiprotocol Label Switching (GMPLS) User-
              Network Interface (UNI): Resource ReserVation Protocol-
              Traffic Engineering (RSVP-TE) Support for the Overlay
              Model", RFC 4208, DOI 10.17487/RFC4208, October 2005,
              <https://www.rfc-editor.org/info/rfc4208>.

   [RFC4872]  Lang, J., Ed., Rekhter, Y., Ed., and D. Papadimitriou,
              Ed., "RSVP-TE Extensions in Support of End-to-End
              Generalized Multi-Protocol Label Switching (GMPLS)
              Recovery", RFC 4872, DOI 10.17487/RFC4872, May 2007,
              <https://www.rfc-editor.org/info/rfc4872>.

   [RFC4873]  Berger, L., Bryskin, I., Papadimitriou, D., and A. Farrel,
              "GMPLS Segment Recovery", RFC 4873, DOI 10.17487/RFC4873,
              May 2007, <https://www.rfc-editor.org/info/rfc4873>.

   [RFC5520]  Bradford, R., Ed., Vasseur, JP., and A. Farrel,
              "Preserving Topology Confidentiality in Inter-Domain Path
              Computation Using a Path-Key-Based Mechanism", RFC 5520,
              DOI 10.17487/RFC5520, April 2009,
              <https://www.rfc-editor.org/info/rfc5520>.

   [RFC6387]  Takacs, A., Berger, L., Caviglia, D., Fedyk, D., and J.
              Meuric, "GMPLS Asymmetric Bandwidth Bidirectional Label
              Switched Paths (LSPs)", RFC 6387, DOI 10.17487/RFC6387,
              September 2011, <https://www.rfc-editor.org/info/rfc6387>.

Authors' Addresses

   Zafar Ali
   Cisco Systems

   Email: zali@cisco.com


   Siva Sivabalan
   Cisco Systems

   Email: msiva@cisco.com


   Clarence Filsfils
   Cisco Systems

   Email: cfilsfil@cisco.com





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   Robert Varga
   Pantheon Technologies

   Email: nite@hq.sk


   Victor Lopez
   Telefonica

   Email: victor.lopezalvarez@telefonica.com


   Oscar Gonzalez de Dios
   Telefonica

   Email: oscar.gonzalezdedios@telefonica.com


   Haomian Zheng (Editor)
   Huawei Technologies
   H1-1-A043S Huawei Industrial Base, Songshanhu
   Dongguan, Guangdong  523808
   P.R.China

   Email: zhenghaomian@huawei.com


   Xian Zhang
   Huawei Technologies
   G1-2, Huawei Industrial Base, Bantian, Longgang District
   Shenzhen, Guangdong  518129
   P.R.China

   Email: zhang.xian@huawei.com

















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