The authors comprehensively review and discuss the vulnerability of optical networks towards various types of security threats that could appear in the network optical layer: passive eavesdropping attacks and active optical attacks like in-band jamming, out-of-band crosstalk. The authors comprehensively review and discuss the vulnerability of optical networks towards various types of security threats that could appear in the network optical layer: passive eavesdropping attacks and active optical attacks like in-band jamming, out-of-band crosstalk. Optical fiber communications are essential for all types of long- and short-distance transmissions. The aim of this paper is to analyze the previously presented security risks and, based on measurements, provide the risk level evaluation. The major risk is the possibility of inserting a splitter. Fiber optic tapping, also known as fiber optic eavesdropping or fiber optic interception, is a process where unauthorized parties intercept and monitor data as it travels through fiber optic cables. Unlike traditional copper cables, fiber optics use light signals to transmit data, making it. Abstract: This study addresses the issues of optical network survivability to attacks in the optical physical layer. With millions of miles of fiber optic cables stretching across the.