1. PCE Applicability for Inter-Layer MPLS and GMPLS Traffic Engineering draft-oki-pce-inter-layer-app-00.txt
Mar. 20, 2006
Eiji Oki (NTT)
Jean-Louis Le Roux (France Telecom)
Adrian Farrel (Old Dog Consulting)

2. Draft overview
The applicability of the PCE-based path computation architecture to inter-layer traffic engineering.
Inter-layer path computation models
Single PCE inter-layer path computation
Multiple PCE inter-layer path computation
Inter-layer path control models
Higher-layer signaling trigger model
Cooperation model between PCE and Virtual Network Topology Manager (VNTM)
Text related to the applicability of PCEs for inter-layer path computation was moved from the inter-layer requirement draft to this applicability draft.

3. Inter-layer PCE deployment scenarios
Single PCE with multi-layer visibility
Cooperating single-layer PCEs
PCE
High-layer network
Router
Lower-layer network
OXC
High-layer network
Router
PCE_Hi
Lower-layer network
PCE_Lo
OXC

4. Mono-layer path and multi-layer path
The PCE computes and returns a path to the PCC that the PCC can use to build a higher-layer or lower-layer LSP. There are two options.
Mono-layer path
A path that includes only TE-links from the same layer.
Multi-layer path
A path that includes TE links from distinct layers.

5. Inter-Layer Path Control Models
Higher-Layer Signaling Trigger Model
PCE performs inter-layer path computation.
Higher-layer signaling triggers lower-layer path setup.
PCE
Multi-layer path: H1-H2-L3-H4-H5 1 2
High-layer network
Egress
Ingress 3 H1 H5 H2 H3 H4
Higher-layer
signaling trigger L1 L2
Lower-layer network L3 4

6. Inter-Layer Path Control Models (cont’d)
Cooperation model between PCE and Virtual Network Topology Manager (VNTM)
VNTM is considered as a functional element.
PCE performs inter-layer path computation.
VNTM controls lower-layer path setup. 2
VNT
Manager
PCE
Mono-layer path:
H1-H2-H4-H5 6 1 7 5 3
Egress
High-layer network
Ingress 5 H1 H5 H2 H3 H4
Lower-layer network L1 L2 L3 4

7. Next step… Adopt as WG document.
Existing protocol evaluation to see whether some protocol extensions are required to support inter-layer path control models.
Requests for feedback.