PCE Working Group                                               D. Dhody
Internet-Draft                                       Huawei Technologies
Updates: 5440 (if approved)                                      D. King
Intended status: Standards Track                    Lancaster University
Expires: February 24, May 16, 2018                                          A. Farrel
                                                        Juniper Networks
                                                         August 23,
                                                       November 12, 2017

   Experimental Codepoint Allocation for the Path Computation Element
                     communication Protocol (PCEP)
                 draft-ietf-pce-pcep-exp-codepoints-02
                 draft-ietf-pce-pcep-exp-codepoints-03

Abstract

   IANA assigns values to the Path Computation Element (PCE)
   communication Protocol (PCEP) parameters (messages, objects, TLVs).
   IANA established a new top-level registry to contain all PCEP codepoints
   and sub-registries.  This top-level registry contains sub-registries
   for PCEP message, object and TLV types.  The allocation policy for
   each new
   registry of these sub-registries is by IETF Review.

   This document updates RFC 5440 by changing the allocation policies
   for these three registries to mark some of the code points as
   assigned for Experimental Use.

Status of This Memo

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  PCEP Messages . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  PCEP Objects  . . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  PCEP TLVs . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   5.  Handling of Unknown Experimentation . . . . . . . . . . . . .   4
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
     6.1.  New PCEP Messages . . . . . . . . . . . . . . . . . . . .   4
     6.2.  New PCEP Objects  . . . . . . . . . . . . . . . . . . . .   4
     6.3.  New PCEP TLVs . . . . . . . . . . . . . . . . . . . . . .   5
   7.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   8.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   5
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Appendix A.  Other PCEP Registries  . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   The Path Computation Element communication Protocol (PCEP) [RFC5440]
   provides mechanisms for Path Computation Elements (PCEs) to perform
   path computations in response to Path Computation Clients (PCCs)
   requests.

   Further, in order to support use cases described in [RFC8051],
   [I-D.ietf-pce-stateful-pce]
   [RFC8231] specifies a set of extensions to PCEP to enable stateful
   control of MPLS-TE and GMPLS LSPs via PCEP.
   [I-D.ietf-pce-pce-initiated-lsp] describes the setup, maintenance and
   teardown of PCE-initiated LSPs under the stateful PCE model.

   In section 9 of [RFC5440], IANA assigns values to the PCEP protocol
   parameters (messages, objects, TLVs).  IANA established a new top- level
   registry to contain all PCEP codepoints and sub-registries.  This
   top-level registry contains sub-registries for PCEP message, object
   and TLV types.  The allocation policy for each new registry of these sub-
   registries is by IETF Review as
   described in [RFC8126].  Also, early allocation
   [RFC7120] provides some latitude for allocation of these code points,
   but is reserved for features that are considered appropriately
   stable.

   With some recent advancement,

   Recently, there is have been rapid advancements in PCE technology, which
   has created an enhanced need to experiment with PCEP.  It is often
   necessary to use some sort of number or constant in order to actually
   test or experiment with the new function, even when testing in a
   closed environment.  In order to run experiments, it is important
   that the value won't collide not only with existing codepoints but
   any future allocation.

   This document updates [RFC5440] by changing the allocation policies
   for these three registries to mark some of the code points as
   assigned for Experimental Use.  See [RFC3692] for further discussion
   of the use of experimental codepoints.

2.  PCEP Messages

   PCEP message types are in the range 0 to 255.  This document sets
   aside message types 252-255 for experimentation as described in
   Section 6.1.

3.  PCEP Objects

   PCEP objects are identified by values in the range 0 to 255.  This
   document sets aside object identifiers 248-255 for experimentation as
   described in Section 6.2.

4.  PCEP TLVs

   PCEP TLV type codes are in the range 0 to 65535.  This document sets
   aside object identifiers 65504-65535 for experimentation as described
   in Section 6.2.

5.  Handling of Unknown Experimentation

   A PCEP implementation that receives an experimental PCEP message,
   that it does not recognize, would react as per section 6.9 of
   [RFC5440] by sending a PCErr message with Error-value=2 (capability
   not supported).

   A PCE that

   If a PCEP speaker does not recognize understand or support an experimental PCEP object, will
   reject
   object then the way it handles this situation depends on the entire PCEP message and send
   type.  For example, a PCE error message with
   Error- Type="Unknown Object" or "Not supported object" as described handles an unknown object in the Path
   Computation Request (PCReq) message according to the rules of
   [RFC5440].  A PCC handles an unknown object in an Update (PCUpd)
   message according to the rules of [RFC8231] and, in an LSP Initiate
   Request (PCInitiate) message, according to the rules of
   [I-D.ietf-pce-pce-initiated-lsp].  Any document that adds a new PCEP
   message type must specify how to handle unknown objects on that
   message.

   As per section 7.1 of [RFC5440], unknown experimental PCEP TLV would
   be ignored.

6.  IANA Considerations

   IANA maintains the "Path Computation Element Protocol (PCEP) Numbers"
   at <http://www.iana.org/assignments/pcep>.

6.1.  New PCEP Messages

   Within this registry IANA maintains a sub-registry for PCEP Messages
   (see PCEP Messages at <http://www.iana.org/assignments/pcep>).

   IANA is requested to change the registration procedure for this
   registry to read as follows:

      0-251   IETF Review
      252-255 Experimental Use

   IANA is also requested to mark the values 252-255 in the registry
   accordingly.

6.2.  New PCEP Objects

   Within this registry IANA maintains a sub-registry for PCEP Objects
   (see PCEP Objects at <http://www.iana.org/assignments/pcep>).

   IANA is requested to change the registration procedure for this
   registry to read as follows:

      0-247   IETF Review
      248-255 Experimental Use

   IANA is also requested to mark the values 248-255 in the registry
   accordingly.

6.3.  New PCEP TLVs

   Within this registry IANA maintains a sub-registry for PCEP TLVs (see
   PCEP TLV Type Indicators at <http://www.iana.org/assignments/pcep>).

   IANA is requested to change the registration procedure for this
   registry to read as follows:

      0-65503     IETF Review
      65504-65535 Experimental Use

   IANA is also requested to mark the values 65504-65535 in the registry
   accordingly.

7.  Security Considerations

   This document does not introduce any new security considerations to
   the existing protocol.  Refer to [RFC5440] for further details of the
   specific security measures.

   [RFC3692] asserts that the existence of experimental code points
   introduce no new security considerations.  However, implementations
   accepting experimental codepoints need to take care in how they parse
   and process the messages, objects, and TLVs in case they come,
   accidentally
   accidentally, from another experiment.

8.  Acknowledgments

   The authors would like to thank Ramon Casellas, Jeff Tantsura,
   Jonathan Hardwick, Julien
   Mueric, Lou Berger, Michael Shroff, and Andrew Dolganow for their
   feedback and suggestions.

   We would like to thank Jonathan Hardwick for shepherding this
   document and providing comments with text suggestions.

9.  References

9.1.  Normative References

   [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>.
              <https://www.rfc-editor.org/info/rfc5440>.

   [RFC8126]  Cotton, M., Leiba, B., and T. Narten, "Guidelines for
              Writing an IANA Considerations Section in RFCs", BCP 26,
              RFC 8126, DOI 10.17487/RFC8126, June 2017,
              <https://www.rfc-editor.org/info/rfc8126>.

   [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>.

   [I-D.ietf-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-ietf-pce-pce-initiated-lsp-11 (work in
              progress), October 2017.

9.2.  Informative References

   [RFC3692]  Narten, T., "Assigning Experimental and Testing Numbers
              Considered Useful", BCP 82, RFC 3692,
              DOI 10.17487/RFC3692, January 2004, <https://www.rfc-
              editor.org/info/rfc3692>.
              <https://www.rfc-editor.org/info/rfc3692>.

   [RFC7120]  Cotton, M., "Early IANA Allocation of Standards Track Code
              Points", BCP 100, RFC 7120, DOI 10.17487/RFC7120, January
              2014, <https://www.rfc-editor.org/info/rfc7120>.

   [RFC8051]  Zhang, X., Ed. and I. Minei, Ed., "Applicability of a
              Stateful Path Computation Element (PCE)", RFC 8051,
              DOI 10.17487/RFC8051, January 2017, <https://www.rfc-
              editor.org/info/rfc8051>.

   [I-D.ietf-pce-stateful-pce]
              Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP
              Extensions for Stateful PCE", draft-ietf-pce-stateful-
              pce-21 (work in progress), June 2017.

   [I-D.ietf-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-ietf-pce-pce-initiated-lsp-10 (work in
              progress), June 2017.
              <https://www.rfc-editor.org/info/rfc8051>.

Appendix A.  Other PCEP Registries

   Based on the feedback from the PCE WG, it was decided to focus allocate an
   Experimental code point range only on
   the essentials in the scope of message, object and TLV
   sub-registries.  The justification for this documents.  For others,
   Experiments can decision is that, if an
   experiment finds that it wants to use a new code point in another
   PCEP sub-registry, it can implement the same function using a new
   experimental TLV/Object object or TLV instead.

Authors' Addresses

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

   EMail: dhruv.ietf@gmail.com

   Daniel King
   Lancaster University
   UK

   EMail: d.king@lancaster.ac.uk

   Adrian Farrel
   Juniper Networks
   UK

   EMail: afarrel@juniper.net