Shared sub-path protection algorithm for multi-link failures in WDM mesh networks

We propose a novel algorithm, called dynamic shared sub-path protection (DSSPP), for completely protecting the multi-link failures of the single shared risk link group (SRLG) breakdown in WDM mesh networks. DSSPP firstly searches a primary path for each connection request and segments the primary path into several equal-length sub-paths, and then it searches a SRLG-disjoint backup path for each sub-path. If two sub-paths are SRLG-disjoint, then their backup paths can share the common resources. When computing the paths, we consider the load balance and the backup resources sharing degree. Thus, the resource utilization ratio would be improved and the blocking ratio would be reduced. Under dynamic traffic with different load, the simulation results show that DSSPP not only can completely protect the multi-link failures of the single-SRLG breakdown but also can make the appreciated tradeoffs between the resource utilization ratio (or blocking ratio) and the protection-switching time.