draft-ietf-pce-global-concurrent-optimization-09.txt   draft-ietf-pce-global-concurrent-optimization-10.txt 
Network Working Group Y. Lee Network Working Group Y. Lee
Internet-Draft Huawei Internet-Draft Huawei
Intended status: Standards Track JL. Le Roux Intended status: Standards Track JL. Le Roux
Expires: Aug 2009 France Telecom Expires: Aug 2009 France Telecom
D. King D. King
Old Dog Consulting Old Dog Consulting
E. Oki E. Oki
Univeristy of Electro Communications Univeristy of Electro Communications
March 24, 2009 March 29, 2009
Path Computation Element Communication Protocol (PCEP) Requirements and Path Computation Element Communication Protocol (PCEP) Requirements and
Protocol Extensions In Support of Global Concurrent Optimization Protocol Extensions In Support of Global Concurrent Optimization
draft-ietf-pce-global-concurrent-optimization-09.txt draft-ietf-pce-global-concurrent-optimization-10.txt
Status of this Memo Status of this Memo
This Internet-Draft is submitted to IETF in full conformance with the This Internet-Draft is submitted to IETF in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on August 24, 2009. This Internet-Draft will expire on August 29, 2009.
Abstract Abstract
The Path Computation Element (PCE) is a network component, The Path Computation Element Communication Protocol (PCEP) allows
application, or node that is capable of performing path computations Path Computation Clients (PCCs) to request path computations from
at the request of Path Computation Clients (PCCs). The PCE is Path Computation Elements (PCEs), and lets the PCEs return responses.
applied in Multiprotocol Label Switching Traffic Engineering
(MPLS-TE) networks and in Generalized MPLS (GMPLS) networks to
determine the routes of Label Switched Paths (LSPs) through the
network. In this context a PCC may be a Label Switching Router
(LSR), a Network Management System (NMS), or another PCE. The Path
Computation Element Communication Protocol (PCEP) is specified for
communications between PCCs and PCEs, and between cooperating PCEs.
When computing or re-optimizing the routes of a set of TE LSPs When computing or re-optimizing the routes of a set of TE LSPs
through a network it may be advantageous to perform bulk path through a network it may be advantageous to perform bulk path
computations in order to avoid blocking problems and to achieve more computations in order to avoid blocking problems and to achieve more
optimal network-wide solutions. Such bulk optimization is termed optimal network-wide solutions. Such bulk optimization is termed
Global Concurrent Optimization (GCO). A GCO is able to Global Concurrent Optimization (GCO). A GCO is able to
simultaneously consider the entire topology of the network and the simultaneously consider the entire topology of the network and the
complete set of existing TE LSPs, and their respective constraints, complete set of existing TE LSPs, and their respective constraints,
and look to optimize or re-optimize the entire network to satisfy all and look to optimize or re-optimize the entire network to satisfy all
constraints for all TE LSPs. A GCO may also be applied to some constraints for all TE LSPs. A GCO may also be applied to some
subset of the TE LSPs in a network. The GCO application is primarily subset of the TE LSPs in a network. The GCO application is primarily
a Network Management System (NMS) solution. a Network Management System (NMS) solution.
While GCO is applicable to any simultaneous request for multiple TE
LSPs (for example, a request for end-to-end protection), it is not
envisaged that global concurrent reoptimization would be applied in a
network (such as an MPLS-TE network) that contains a very large
number of very low bandwidth or zero bandwidth TE LSPs since the
large scope of the problem and the small benefit of concurrent
reoptimization relative to single TE LSP reoptimization is unlikely
to make the process worthwhile. Further, applying global concurrent
reoptimization in a network with a high rate of change of TE LSPs
(churn) is not advised because of the likelihood that TE LSPs would
change before they could be globally reoptimized. Global
reoptimization is more applicable to stable networks such as
transport networks or those with long-term TE LSP tunnels.
This document provides application-specific requirements and the PCEP This document provides application-specific requirements and the PCEP
extensions in support of GCO applications. extensions in support of GCO applications.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6
3. Applicability of Global Concurrent Optimization (GCO) . . . . 7 3. Applicability of Global Concurrent Optimization (GCO) . . . . 7
3.1. Application of the PCE Architecture . . . . . . . . . . . 7 3.1. Application of the PCE Architecture . . . . . . . . . . . 7
3.2. Greenfield Optimization . . . . . . . . . . . . . . . . . 8 3.2. Greenfield Optimization . . . . . . . . . . . . . . . . . 8
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