The Cisco ONS 15500 Series Protection Switch Module (PSM) provides fiber trunk protection in a point-to-point Metro dense wavelength division multiplexing (DWDM) network. The PSM provides protection against a fiber cut by optically splitting the data streams over two diverse paths. This new protection scheme now offers disaster recovery and business continuance solutions based on the Cisco ONS 15530 and ONS 15540 at even more competitive price points.