Dual failure resiliency on single failure protected packet optical integrated networks

A simulation study on four packet optical integrated networks shows that flows are fully restorable on 41%–94% dual fiber-cut scenarios where single failure restoration is enabled on the packet layer and no protection is available on the optical layer. This ratio increases to 94%-99.7% after the optical layer adds the path protection. This demonstrates the incompetence of simple combination of single failure protections on both layers using existing techniques, and the necessity of protection coordination across layers for full dual failure restorability.