Network Working Group E. Oki
Request for Comments: 5623 University of Electro-Communications
Category: Informational T. Takeda
NTT
JL. Le Roux
France Telecom
A. Farrel
Old Dog Consulting
September 2009
Framework for PCE-Based Inter-Layer MPLS and GMPLS Traffic Engineering
Abstract
A network may comprise multiple layers. It is important to globally
optimize network resource utilization, taking into account all layers
rather than optimizing resource utilization at each layer
independently. This allows better network efficiency to be achieved
through a process that we call inter-layer traffic engineering. The
Path Computation Element (PCE) can be a powerful tool to achieve
inter-layer traffic engineering.
This document describes a framework for applying the PCE-based
architecture to inter-layer Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) traffic engineering. It provides
suggestions for the deployment of PCE in support of multi-layer
networks. This document also describes network models where PCE
performs inter-layer traffic engineering, and the relationship
between PCE and a functional component called the Virtual Network
Topology Manager (VNTM).
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
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Table of Contents
1. Introduction ....................................................3
1.1. Terminology ................................................3
2. Inter-Layer Path Computation ....................................4
3. Inter-Layer Path Computation Models .............................7
3.1. Single PCE Inter-Layer Path Computation ....................7
3.2. Multiple PCE Inter-Layer Path Computation ..................7
3.3. General Observations ......................................10
4. Inter-Layer Path Control .......................................10
4.1. VNT Management ............................................10
4.2. Inter-Layer Path Control Models ...........................11
4.2.1. PCE-VNTM Cooperation Model .........................11
4.2.2. Higher-Layer Signaling Trigger Model ...............13
4.2.3. NMS-VNTM Cooperation Model .........................16
4.2.4. Possible Combinations of Inter-Layer Path
Computation and Inter-Layer Path Control Models ....21
5. Choosing between Inter-Layer Path Control Models ...............22
5.1. VNTM Functions ............................................22
5.2. Border LSR Functions ......................................23
5.3. Complete Inter-Layer LSP Setup Time .......................24
5.4. Network Complexity ........................................24
5.5. Separation of Layer Management ............................25
6. Stability Considerations .......................................25
7. Manageability Considerations ...................................26
7.1. Control of Function and Policy ............................27
7.1.1. Control of Inter-Layer Computation Function ........27
7.1.2. Control of Per-Layer Policy ........................27
7.1.3. Control of Inter-Layer Policy ......................27
7.2. Information and Data Models ...............................28
7.3. Liveness Detection and Monitoring .........................28
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