Updated Rules for Processing Stateful PCE Request Parameters Flags
RFC 8786

Document Type RFC - Proposed Standard (May 2020; No errata)
Updates RFC 8231
Last updated 2020-05-31
Replaces draft-farrel-pce-stateful-flags
Stream IETF
Formats plain text html xml pdf htmlized bibtex
Reviews
Stream WG state Submitted to IESG for Publication
Document shepherd Hariharan Ananthakrishnan
Shepherd write-up Show (last changed 2019-12-07)
IESG IESG state RFC 8786 (Proposed Standard)
Consensus Boilerplate Yes
Telechat date
Responsible AD Deborah Brungard
Send notices to Hariharan Ananthakrishnan <hari@netflix.com>
IANA IANA review state Version Changed - Review Needed
IANA action state RFC-Ed-Ack


Internet Engineering Task Force (IETF)                         A. Farrel
Request for Comments: 8786                            Old Dog Consulting
Updates: 8231                                                   May 2020
Category: Standards Track                                               
ISSN: 2070-1721

   Updated Rules for Processing Stateful PCE Request Parameters Flags

Abstract

   Extensions to the Path Computation Element Communication Protocol
   (PCEP) to support stateful Path Computation Elements (PCEs) are
   defined in RFC 8231.  One of the extensions is the Stateful PCE
   Request Parameters (SRP) object.  That object includes a Flags field
   that is a set of 32 bit flags, and RFC 8281 defines an IANA registry
   for tracking assigned flags.  However, RFC 8231 does not explain how
   an implementation should set unassigned flags in transmitted
   messages, nor how an implementation should process unassigned,
   unknown, or unsupported flags in received messages.

   This document updates RFC 8231 by defining the correct behaviors.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   https://www.rfc-editor.org/info/rfc8786.

Copyright Notice

   Copyright (c) 2020 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.  Requirements Language
   3.  Updated Procedures
     3.1.  Advice for Specification of New Flags
     3.2.  Flags Field of the SRP Object
   4.  Compatibility Considerations
   5.  Management Considerations
   6.  Security Considerations
   7.  IANA Considerations
   8.  References
     8.1.  Normative References
     8.2.  Informative References
   Acknowledgements
   Author's Address

1.  Introduction

   [RFC5440] describes the Path Computation Element Communication
   Protocol (PCEP).  PCEP defines the communication between a Path
   Computation Client (PCC) and a Path Computation Element (PCE), or
   between PCEs, enabling computation of Multiprotocol Label Switching
   (MPLS) for Traffic Engineering Label Switched Path (TE LSP)
   characteristics.

   [RFC8231] specifies a set of extensions to PCEP to enable stateful
   control of LSPs within and across PCEP sessions in compliance with
   [RFC4657].  It includes mechanisms to effect Label Switched Path
   (LSP) State Synchronization between PCCs and PCEs, delegation of
   control over LSPs to PCEs, and PCE control of timing and sequence of
   path computations within and across PCEP sessions.

   One of the extensions defined in [RFC8231] is the Stateful PCE
   Request Parameters (SRP) object.  That object includes a Flags field
   that is a set of 32 bit flags, and RFC 8281 defines an IANA registry
   for tracking assigned flags.  However, RFC 8231 does not explain how
   an implementation should set unassigned flags in transmitted
   messages, nor how an implementation should process unassigned or
   unknown flags in received messages.

   Furthermore, [RFC8231] gives no guidance to the authors of future
   specifications about how to describe the interaction between flags
   that have already been defined and flags being defined in the new
   specifications.

   This document updates RFC 8231 by defining the correct behaviors.

2.  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.

3.  Updated Procedures

3.1.  Advice for Specification of New Flags

   Section 7 of [RFC8231] introduces changes to existing PCEP objects
   and defines new PCEP objects and TLVs in support of stateful PCE
   functionality.  That text does not advise future specifications on
   how to describe the interaction between flags that may be defined.
Show full document text