PCEP Extensions for Segment Routing
draft-ietf-pce-segment-routing-15

Document Type Active Internet-Draft (pce WG)
Last updated 2019-02-12
Replaces draft-sivabalan-pce-segment-routing
Stream IETF
Intended RFC status Proposed Standard
Formats plain text xml pdf html bibtex
Reviews
Stream WG state Submitted to IESG for Publication
Document shepherd Dhruv Dhody
Shepherd write-up Show (last changed 2018-10-13)
IESG IESG state IESG Evaluation::AD Followup
Consensus Boilerplate Yes
Telechat date
Has a DISCUSS. Needs one more YES or NO OBJECTION position to pass.
Responsible AD Deborah Brungard
Send notices to Dhruv Dhody <dhruv.ietf@gmail.com>
IANA IANA review state Version Changed - Review Needed
IANA action state None
PCE                                                         S. Sivabalan
Internet-Draft                                               C. Filsfils
Updates: 8408 (if approved)                          Cisco Systems, Inc.
Intended status: Standards Track                             J. Tantsura
Expires: August 16, 2019                                    Apstra, Inc.
                                                           W. Henderickx
                                                                   Nokia
                                                             J. Hardwick
                                                     Metaswitch Networks
                                                       February 12, 2019

                  PCEP Extensions for Segment Routing
                   draft-ietf-pce-segment-routing-15

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 Routing 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 Communication 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 constraints and
   optimization criteria in SR networks.

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.

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/.

Sivabalan, et al.        Expires August 16, 2019                [Page 1]
Internet-Draft     PCEP Extensions for Segment Routing     February 2019

   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."

   This Internet-Draft will expire on August 16, 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  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  Overview of PCEP Operation in SR Networks . . . . . . . . . .   5
   4.  Object Formats  . . . . . . . . . . . . . . . . . . . . . . .   7
     4.1.  The OPEN Object . . . . . . . . . . . . . . . . . . . . .   7
       4.1.1.  The Path Setup Type Capability TLV  . . . . . . . . .   7
       4.1.2.  The SR PCE Capability sub-TLV . . . . . . . . . . . .   8
     4.2.  The RP/SRP Object . . . . . . . . . . . . . . . . . . . .   9
     4.3.  ERO . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
       4.3.1.  SR-ERO Subobject  . . . . . . . . . . . . . . . . . .   9
       4.3.2.  NAI Associated with SID . . . . . . . . . . . . . . .  12
     4.4.  RRO . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
     4.5.  METRIC Object . . . . . . . . . . . . . . . . . . . . . .  14
   5.  Procedures  . . . . . . . . . . . . . . . . . . . . . . . . .  14
     5.1.  Exchanging the SR PCE Capability  . . . . . . . . . . . .  14
     5.2.  ERO Processing  . . . . . . . . . . . . . . . . . . . . .  16
       5.2.1.  SR-ERO Validation . . . . . . . . . . . . . . . . . .  16
       5.2.2.  Interpreting the SR-ERO . . . . . . . . . . . . . . .  18
     5.3.  RRO Processing  . . . . . . . . . . . . . . . . . . . . .  20
   6.  Backward Compatibility  . . . . . . . . . . . . . . . . . . .  20
   7.  Management Considerations . . . . . . . . . . . . . . . . . .  21
Show full document text