Most of the Routing and Wavelength Assignment（RWA）problems are related to blocking rate

load balancing

signal damage and physical attacks

and rarely involved with the dependency of services on the link working state.However

link failures will surely cause the deterioration of the traffic security performances of the entire network.From the perspective of traffic risks

this article describes the impacts of link failures on the entire network services and proposes a network risk-based RWA algorithm

i.e.R-RWA.In the phase of routing assignment

this algorithm allocates the routing scheme with minor network risks to lightpath requests so as to reduce the impacts of the link failures on the entire network services.The simulation results show that compared with the classical Dijkstra + FF

this algorithm can effectively reduce the network security risks and improve the network anti-risk ability.