Network Working Group                                       S. Sivabalan
Internet-Draft                                                 J. Medved
Intended status: Standards Track                             C. Filsfils
Expires: September 22, 2016                          Cisco Systems, Inc.
                                                               E. Crabbe

                                                               R. Raszuk
                                                           Mirantis Inc.
                                                                V. Lopez
                                                          Telefonica I+D
                                                             J. Tantsura
                                                                Ericsson
                                                           W. Henderickx
                                                          Alcatel Lucent
                                                             J. Hardwick
                                                     Metaswitch Networks
                                                          March 21, 2016


                  PCEP Extensions for Segment Routing
                 draft-ietf-pce-segment-routing-07.txt

Abstract

   Segment Routing (SR) enables any head-end node to select any path
   without relying on a hop-by-hop signaling technique (e.g., LDP or
   RSVP-TE).  It depends only on "segments" that are advertised by Link-
   State Interior Gateway Protocols (IGPs).  A Segment Routed Path can
   be derived from a variety of mechanisms, including an IGP Shortest
   Path Tree (SPT), explicit configuration, or a Path Computation
   Element (PCE).  This document specifies extensions to the Path
   Computation Element Protocol (PCEP) that allow a stateful PCE to
   compute and initiate Traffic Engineering (TE) paths, as well as a PCC
   to request a path subject to certain constraint(s) and optimization
   criteria in SR networks.

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.





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Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   4
   3.  Overview of PCEP Operation in SR Networks . . . . . . . . . .   5
   4.  SR-Specific PCEP Message Extensions . . . . . . . . . . . . .   7
   5.  Object Formats  . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  The OPEN Object . . . . . . . . . . . . . . . . . . . . .   7
       5.1.1.  The SR PCE Capability TLV . . . . . . . . . . . . . .   7
     5.2.  The RP/SRP Object . . . . . . . . . . . . . . . . . . . .   8
     5.3.  ERO Object  . . . . . . . . . . . . . . . . . . . . . . .   8
       5.3.1.  SR-ERO Subobject  . . . . . . . . . . . . . . . . . .   9
       5.3.2.  NAI Associated with SID . . . . . . . . . . . . . . .  11
       5.3.3.  ERO Processing  . . . . . . . . . . . . . . . . . . .  12
     5.4.  RRO Object  . . . . . . . . . . . . . . . . . . . . . . .  13
       5.4.1.  RRO Processing  . . . . . . . . . . . . . . . . . . .  14
     5.5.  METRIC Object . . . . . . . . . . . . . . . . . . . . . .  14
   6.  Backward Compatibility  . . . . . . . . . . . . . . . . . . .  15
   7.  Management Considerations . . . . . . . . . . . . . . . . . .  15
     7.1.  Policy  . . . . . . . . . . . . . . . . . . . . . . . . .  15
     7.2.  The PCEP Data Model . . . . . . . . . . . . . . . . . . .  15



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   8.  Security Considerations . . . . . . . . . . . . . . . . . . .  15
   9.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  15
     9.1.  PCEP Objects  . . . . . . . . . . . . . . . . . . . . . .  16
     9.2.  PCEP-Error Object . . . . . . . . . . . . . . . . . . . .  16
     9.3.  PCEP TLV Type Indicators  . . . . . . . . . . . . . . . .  17
     9.4.  New Path Setup Type . . . . . . . . . . . . . . . . . . .  17
     9.5.  New Metric Type . . . . . . . . . . . . . . . . . . . . .  17
   10. Contributors  . . . . . . . . . . . . . . . . . . . . . . . .  17