PCC-PCE Communication and PCE Discovery Requirements for Inter-Layer Traffic Engineering
RFC 6457

Internet Engineering Task Force (IETF)                    T. Takeda, Ed.
Request for Comments: 6457                                           NTT
Category: Informational                                        A. Farrel
ISSN: 2070-1721                                       Old Dog Consulting
                                                           December 2011

        PCC-PCE Communication and PCE Discovery Requirements for
                    Inter-Layer Traffic Engineering

Abstract

   The Path Computation Element (PCE) provides functions of path
   computation in support of traffic engineering in networks controlled
   by Multi-Protocol Label Switching (MPLS) and Generalized MPLS
   (GMPLS).

   MPLS and GMPLS networks may be constructed from layered client/server
   networks.  It is advantageous for overall network efficiency to
   provide end-to-end traffic engineering across multiple network
   layers.  PCE is a candidate solution for such requirements.

   Generic requirements for a communication protocol between Path
   Computation Clients (PCCs) and PCEs are presented in RFC 4657, "Path
   Computation Element (PCE) Communication Protocol Generic
   Requirements".  Generic requirements for a PCE discovery protocol are
   presented in RFC 4674, "Requirements for Path Computation Element
   (PCE) Discovery".

   This document complements the generic requirements and presents
   detailed sets of PCC-PCE communication protocol requirements and PCE
   discovery protocol requirements for inter-layer traffic engineering.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6457.

Takeda, et al.                Informational                     [Page 1]
RFC 6457              PCE Inter-Layer Requirements         December 2011

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   document authors.  All rights reserved.

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Table of Contents

   1. Introduction ....................................................2
      1.1. Terminology ................................................3
   2. Motivation for PCE-Based Inter-Layer Path Computation ...........4
   3. PCC-PCE Communication and Discovery Requirements for
      Inter-Layer .....................................................4
      3.1. PCC-PCE Communication ......................................5
           3.1.1. Control of Inter-Layer Path Computation .............5
           3.1.2. Control of the Type of Path to Be Computed ..........5
           3.1.3. Communication of Inter-Layer Constraints ............6
           3.1.4. Adaptation Capability ...............................7
           3.1.5. Cooperation between PCEs ............................7
           3.1.6. Inter-Layer Diverse Paths ...........................7
      3.2. Capabilities Advertisements for PCE Discovery ..............7
      3.3. Supported Network Models ...................................8
   4. Manageability Considerations ....................................8
      4.1. Control of Function and Policy .............................8
      4.2. Information and Data Models ................................8
      4.3. Liveness Detection and Monitoring ..........................8
      4.4. Verifying Correct Operation ................................9
      4.5. Requirements on Other Protocols and Functional Components ..9
      4.6. Impact on Network Operation ................................9
   5. Security Considerations ........................................10
   6. Acknowledgments ................................................10
   7. References .....................................................10