Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Benefits of p-Cycles in a Mixed Protection and Restoration Approach François Blouin, Anthony Sack, Wayne D. Grover, Hadi Nasrallah Fourth International Workshop on the Design of Reliable Communication Networks (DRCN 2003) October Banff, Alberta, Canada October 21, 2003

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Introduction Multiple protection and restoration methods may co-exist in optical mesh networks – Automatic protection switching (APS), shared backup path protection (SBPP), mesh span restoration, redial, etc. Benefits of adding p-cycles to a set of these methods? Benefits of planning network capacity jointly for these methods? New joint planning model

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Capacity redundancy vs. Restoration time Restoration time Capacity redundancy APS 1+1 p-Cycles Shared Backup Path Protection True Mesh Path Restoration Mesh Span Restoration

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Fixed CoP selection (without p-cycles) Service model Other possible CoPs, e.g. Unprotected and Redial, not included in analysis. Class of Protection (CoP) APS ms Restoration time p-Cycles80 ms SBPP200 ms Network services Restoration time requirement 15% Demand mix (example case) 30% 55% Applications ≤ 60 ms ≤ 80 ms ≤ 200 ms

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Fixed CoP selection (with p-cycles) Service model Other possible CoPs, e.g. Unprotected and Redial, not included in analysis. Class of Protection (CoP) APS ms Restoration time p-Cycles80 ms SBPP200 ms Network services Restoration time requirement 15% Demand mix (example case) 30% 55% Applications ≤ 60 ms ≤ 80 ms ≤ 200 ms

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Automatic CoP selection with upgrades Service model Other possible CoPs, e.g. Unprotected and Redial, not included in analysis. Class of Protection (CoP) APS ms Restoration time p-Cycles80 ms SBPP200 ms Network services Restoration time requirement 15% Demand mix (example case) 30% 55% Applications ≤ 60 ms ≤ 80 ms ≤ 200 ms

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Planning models Integer Linear Programming general model (AMPL, CPLEX) Minimal capacitydistance for full restorability under single failures Selection of fastest CoPs Separate optimization (fixed CoP selection) Joint optimization (automatic CoP selection) With p-Cycles Without p-Cycles (benchmark) or Min Upgrade to faster CoP whenever economical With p-Cycles

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Two network models U.S. Europe Average nodal degree = 4.73 Average nodal degree = 3.26

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Results – U.S. network Benchmark -3.4% -8.7% CoP upgraded demands: 32% 123

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Results – Europe network -11.6% -14% Benchmark CoP upgraded demands: 24% 123

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Class of Protection upgrade examples Upgrade from p-cycle to APS 1+1 Upgrade from SBPP to p-cycle working p-cycle A C B D E

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Class of Protection upgrade examples Upgrade from p-cycle to APS 1+1 Upgrade from SBPP to p-cycle working p-cycle cap = 10 A C B D E APS “spare” w1 cap = 10 w2 = 10 A C B D E w3 = 20

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Conclusions p-Cycles could replace APS 1+1 for some traffic demands – where slight restoration time penalty is acceptable

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Conclusions p-Cycles could replace APS 1+1 for some traffic demands – where slight restoration time penalty is acceptable New capacity planning model allowing automatic selection of protection & restoration method – Upgrade demand to faster CoP whenever economical

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Conclusions p-Cycles could replace APS 1+1 for some traffic demands – where slight restoration time penalty is acceptable New capacity planning model allowing automatic selection of protection & restoration method – Upgrade demand to faster CoP whenever economical Mixed protection & restoration: – Adding p-cycles: 1% - 19% capacity savings – Jointly plan all CoPs: 4% - 22% capacity savings – Upgrades to faster CoP: % Provide better service for some traffic without adding capacity

Benefits of p-Cycles in a Mixed Protection and Restoration Approach DRCN Thank you