The problem of dynamically establishing dependable connections for multi-granularity traffic streams in wavelength division multiplexing(WDM) networks is investigated.A grooming shared sub-path protection(GSSP) scheme is proposed.To establish a dependable connection,GSSP first searches a primary path for each connection request,and then it segments the found path into several equal-length sub-paths,and computes their corresponding backup paths,respectively.If two sub-paths in GSSP are fiber-disjoint then their backup paths can share backup resources to obtain optimal spare capacity.Based on dynamic traffic with different load,the performance of GSSP has been investigated via simulations.The results show that GSSP can make the tradeoffs between resource utilization and restoration time.