| 摘要 |
The present invention relates to a protection method based on preplanning duality of paths for a unicast and/or a multicast traffic, by extending a network into hierarchy of connected rings to form a hierarchical ring based tree (HRBT) structure. The present method enables a deterministic method to route a frame (or packet) when a primary path to destination is unavailable due to node/link failure, bandwidth crunch, mis-configuration, etc. If both primary and secondary (or alternate) path are pre-provisioned before traffic is allowed, the switch-over time from primary (P) path to secondary (S) path will be minimized, thus enabling 50 ms protection switching in packet network. |
