The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS and GMPLS
RFC 6805
Document | Type | RFC - Informational (November 2012; No errata) | |
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Authors | Daniel King , Adrian Farrel | ||
Last updated | 2018-12-20 | ||
Replaces | draft-king-pce-hierarchy-fwk | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | WG Document | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 6805 (Informational) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Stewart Bryant | ||
IESG note | Julien Meuric (julien.meuric@orange.com) is the document shepherd. | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) D. King, Ed. Request for Comments: 6805 A. Farrel, Ed. Category: Informational Old Dog Consulting ISSN: 2070-1721 November 2012 The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS and GMPLS 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 PCE-based Computation (BRPC) procedure 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 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. King & Farrel Informational [Page 1] RFC 6805 PCE Hierarchy Framework November 2012 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/rfc6805. 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. Table of Contents 1. Introduction ....................................................4 1.1. Problem Statement ..........................................5 1.2. Definition of a Domain .....................................5 1.3. Assumptions and Requirements ...............................6 1.3.1. Metric Objectives ...................................6 1.3.2. Diversity ...........................................7 1.3.2.1. Physical Diversity .........................7 1.3.2.2. Domain Diversity ...........................7 1.3.3. Existing Traffic Engineering Constraints ............7 1.3.4. Commercial Constraints ..............................8 1.3.5. Domain Confidentiality ..............................8 1.3.6. Limiting Information Aggregation ....................8 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 PCE-Based Computation ..................10 2.2.1. Applicability of BRPC When the Domain Path is Not Known .......................................11 3. Hierarchical PCE ...............................................12 4. Hierarchical PCE Procedures ....................................13 4.1. Objective Functions and Policy ............................13 4.2. Maintaining Domain Confidentiality ........................14 4.3. PCE Discovery .............................................14 4.4. Traffic Engineering Database for the Parent Domain ........15Show full document text