Network Working Group Y. Lee
Request for Comments: 5557 Huawei
Category: Standards Track JL. Le Roux
France Telecom
D. King
Old Dog Consulting
E. Oki
University of Electro Communications
July 2009
Path Computation Element Communication Protocol (PCEP) Requirements
and Protocol Extensions in Support of Global Concurrent Optimization
Abstract
The Path Computation Element Communication Protocol (PCEP) allows
Path Computation Clients (PCCs) to request path computations from
Path Computation Elements (PCEs), and lets the PCEs return responses.
When computing or reoptimizing the routes of a set of Traffic
Engineering Label Switched Paths (TE LSPs) through a network, it may
be advantageous to perform bulk path computations in order to avoid
blocking problems and to achieve more optimal network-wide solutions.
Such bulk optimization is termed Global Concurrent Optimization
(GCO). A GCO is able to simultaneously consider the entire topology
of the network and the complete set of existing TE LSPs, and their
respective constraints, and look to optimize or reoptimize the entire
network to satisfy all 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 a Network Management System (NMS) solution.
This document provides application-specific requirements and the PCEP
extensions in support of GCO applications.
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Lee, et al. Standards Track [Page 1]
RFC 5557 PCEP Requirements & Protocol Extensions for GCO July 2009
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Lee, et al. Standards Track [Page 2]
RFC 5557 PCEP Requirements & Protocol Extensions for GCO July 2009
Table of Contents
1. Introduction ....................................................4
2. Terminology .....................................................6
3. Applicability of Global Concurrent Optimization (GCO) ...........6
3.1. Application of the PCE Architecture ........................7
3.2. Greenfield Optimization ....................................8
3.2.1. Single-Layer Traffic Engineering ....................8
3.2.2. Multi-Layer Traffic Engineering .....................8
3.3. Reoptimization of Existing Networks ........................8
3.3.1. Reconfiguration of the Virtual Network
Topology (VNT) ......................................9
3.3.2. Traffic Migration ...................................9
4. PCECP Requirements .............................................10
5. Protocol Extensions for Support of Global Concurrent
Optimization ...................................................13
5.1. Global Objective Function (GOF) Specification .............14
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