1. 67th IETF - San Diego, CA, USA November 8, 2006 PCECP Requirements for support of Global Concurrent Optimization Y. Lee, Huawei, D. King, Aria Networks, E. Oki, NTT

2. 67th IETF - San Diego, CA, USA November 8, 2006 What is Global Concurrent Optimization? An application of path computation in which we compute a large number of TE-paths concurrently to meet a global objective by looking at the entire set of network resources and topology.

3. 67th IETF - San Diego, CA, USA November 8, 2006 Motivation Sequential path computation may result in sub-optimal use of network resources in some applications. Efficient utilization of network resources from a global network perspective that would to translate operations cost saving For example, full network re-optimization A PCE supporting concurrent path computation would have the ability to consider global network capacities and properties, all service requirements and constraints, and then optimally place all services to meet the service requirements within the confines of the network infrastructure.

4. 67th IETF - San Diego, CA, USA November 8, 2006 A simple path computation trap problem Consider a simple network topology All links are 5Mbps Various link costs Node 1 Node 2 Node 3 Node 4 Node 5 Node 6 Cost 1 Cost 1 Cost 1 Cost 10 Cost 10 Cost 10 Cost 10 1.Request two least cost paths form Node-1 to Node-4 with bandwidth 3Mbps. 2.Sequential computation places first LSP on the path 1-2-3-4. Second LSP cannot be placed. 3.Parallel computation can place both LSPs as 1-5-3-4 and 1-2-6-4. Many more LSPs, many ingresses and egresses, and a more complex network make the problem much harder.

5. 67th IETF - San Diego, CA, USA November 8, 2006 Application Scenarios Greenfield Traffic Engineering Re-optimization of Existing Networks –Traffic Migration –Catastrophic Failure Pre-establishment of the H-LSP in Multi-Layer Traffic Engineering Reconfiguration of the VNT

6. 67th IETF - San Diego, CA, USA November 8, 2006 PCE-based Architecture for PCE Global Concurrent Optimization Application PCE TED Head End Nodes Adjacent Nodes NMS application request PCECP request/ response service requests Reference: RFC4655 Section 5.5 – Management-Based PCE Usage

7. 67th IETF - San Diego, CA, USA November 8, 2006 Application-Specific Protocol Requirements Indicator field for global concurrent optimization Global objective function field Global constraints field Global concurrent vector field Indicator for failure of global concurrent optimization Multi-session indicator List of existing LSP to be kept intact More to be identified

8. 67th IETF - San Diego, CA, USA November 8, 2006 Summary & Next Step This I-D provides application-specific PCECP requirements for support of global concurrent optimization This I-D supplements the PCECP generic requirements [RFC4657] and is compliant to PCE-based architecture [RFC4655] To be considered as WG document Solicit complete set of requirements Begin protocol work for this application upon consensus