Daniel King, Old Dog Consulting Adrian Farrel, Old Dog Consulting The Application of the Path Computation Element Architecture to the Determination of a Sequence of Domains in MPLS & GMPLS draft-king-pce-hierarchy-fwk-02.txt Daniel King, Old Dog Consulting Adrian Farrel, Old Dog Consulting 76th IETF Hiroshima

Motivation Using a PCE to compute a path between nodes within a single domain is relatively straightforward Using a PCE to compute paths across multiple domains requires an additional technique This document examines techniques to: Establish the optimum path when the sequence of domains is not known in advance, whilst providing: Path Diversity Domain diversity, allowing the selection of paths that share ingress and egress domains, but do not share transit domains Domain path selection should provide the capability to include or exclude specific border nodes Utilize typical traffic engineering constraints (hop count, bandwidth, lambda continuity, path cost, etc.) 76th IETF Hiroshima

Hierarchical PCE (recap) The Parent PCE maintains a topology map The nodes are the Child domains The map contains the inter-domain links The TE capabilities of the links are also known Parent PCE knows the identify and location of the child PCEs responsible for the Child domains Statically configured Domain confidentiality A Parent PCE is aware of the topology and connections between domains, but is not aware of the contents of the domains Child domains are completely confidential One child cannot know the topology of another Child. Child domains do not know the general domain mesh connectivity 76th IETF Hiroshima

Applicability Inter-domain Path Computation When the Domain Path is Not Known ASON architecture (G-7715-2) H-PCE mechanism fits well within the ASON routing architecture Multiple Routing Areas Multi-level IGP Areas Path computation across multi-area networks consisting of a backbone area and various peripheral areas P2MP and Inter-layer For future study. All applications will require further study and the document will be updated accordingly

Manageability Control of Function and Policy Parent PCE Child PCE Policy Control Need to manage authorization between Parent and Child PCEs Information and Data Models Monitoring of parent/child relationships, the use of PCEP between the parent and child Verifying Correct Operation Number of Child PCE requests Number of successful hierarchical PCE procedures completions on a per-PCE-peer basis Number of hierarchical PCE procedure completion failures on a per- PCE-peer basis Number of hierarchical PCE procedure requests from unauthorized Child PCEs

Summary & Next Steps Good feedback from IETF 75 and OIF Lannion (October) The authors intend this work to be scoped within the current charter. The initial will focus on the application of this model within a small group of domains The authors believe that this work is now stable We would like to move the work into the working group 76th IETF Hiroshima