Protection of Long-Reach PON Traffic through Router Database Synchronization

A resilience strategy is introduced for networks implementing dual homing (dual parenting) of customers, specifically those employing Long-Reach PONs (LR-PONs). Assuming that some mechanism exists to detect network element failures, the discussion concentrates on protocols that propagate information about customer reachability and how this information reroutes traffic in the event of a fault. Each router holds a database indicating which other routers, and which LR-PONs are available within the network, and these are synchronized between routers using IP. This information is used to reroute traffic in the event of failure. Simulation and analysis show that signalling time lies well within 50 ms, leaving sufficient time for redirection of user traffic.