The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS and GMPLS
draft-ietf-pce-hierarchy-fwk-02

The information below is for an old version of the document
Document Type Active Internet-Draft (pce WG)
Authors Daniel King  , Adrian Farrel 
Last updated 2012-05-10
Replaces draft-king-pce-hierarchy-fwk
Stream IETF
Intended RFC status (None)
Formats pdf htmlized (tools) htmlized bibtex
Reviews
Stream WG state WG Document
Document shepherd None
IESG IESG state I-D Exists
Consensus Boilerplate Unknown
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                      D. King (Ed.)
Internet-Draft                                        Old Dog Consulting
Intended Status: Informational                           A. Farrel (Ed.)
Expires: 10 October 2012                              Old Dog Consulting
                                                             10 May 2012   

   The Application of the Path Computation Element Architecture to the
        Determination of a Sequence of Domains in MPLS and GMPLS

                   draft-ietf-pce-hierarchy-fwk-02.txt

Abstract

   Computing optimum routes for Label Switched Paths (LSPs) across
   multiple domains in MPLS Traffic Engineering (MPLS-TE) and GMPLS
   networks presents a problem because no single point of path
   computation is aware of all of the links and resources in each
   domain. A solution may be achieved using the Path Computation
   Element (PCE) architecture.

   Where the sequence of domains is known a priori, various techniques
   can be employed to derive an optimum path. If the domains are
   simply-connected, or if the preferred points of interconnection are
   also known, the Per-Domain Path Computation technique can be used.
   Where there are multiple connections between domains and there is
   no preference for the choice of points of interconnection, the
   Backward Recursive Path Computation Procedure (BRPC) can be used to
   derive an optimal path.

   This document examines techniques to establish the optimum path when
   the sequence of domains is not known in advance. The document
   shows how the PCE architecture can be extended to allow the optimum
   sequence of domains to be selected, and the optimum end-to-end path
   to be derived through the use of a hierarchical relationship between
   domains.

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

King and Farrel                                                [Page 1]

draft-ietf-pce-hierarchy-fwk-02.txt                            May 2012

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   This Internet-Draft will expire on 10 October 2012. 

Copyright Notice

   Copyright (c) 2012 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
   (http://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.

Contents

   1. Introduction..................................................3
      1.1 Problem Statement.........................................4
      1.2 Definition of a Domain............. ......................5
      1.3 Assumptions and Requirements..............................5
          1.3.1 Metric Objectives...................................6
          1.3.2 Domain Diversity....................................7
          1.3.3 Existing Traffic Engineering Constraints............7
          1.3.4 Commercial Constraints..............................7
          1.3.5 Domain Confidentiality..............................7
          1.3.6 Limiting Information Aggregation....................7
          1.3.7 Domain Interconnection Discovery....................8
      1.4 Terminology...............................................8
   2. Examination of Existing PCE Mechanisms........................9
      2.1 Per Domain Path Computation...............................9
      2.2 Backward Recursive Path Computation.......................10
          2.2.1 Applicability of BRPC when the Domain Path is not 
              Known.................................................10
   3. Hierarchical PCE..............................................11
   4. Hierarchical PCE Procedures...................................12
      4.1 Objective Functions and Policy............................12
Show full document text