Abstract: The broad applications and extensive research interests have been placed on ring networks due to its excellent performance in network survivability and its simplicity. A three-node, bi-directional, two-fiber ring network is implemented on the basis of PTDS platform, and a simulation for single fiber failure can be realized through changing the fiber loss and then the receiving power of powermeter of the simulation system. The survivability of the ring network on a single fiber failure is simulated under the given policy for RWA(routing and wavelength assignment). The analysis of simulation result indicates that the ring network introduced in this paper has excellent survivability and the result is helpful in designing the ring network.