Abstract <p>The paper briefly describes the phenomenon of total internal reflection of light fluxes at an interface formed by translucent dielectric media with different refractive indices. The features of the radiation fluxes transport within the framework of the multiple total internal reflection mechanism are described, and it is shown that this mechanism is not related to the nature of light propagation in a symmetric optical fiber. Based on a comparison of model representations and experimental data, a conclusion is drawn about the functioning of fiber-optic structures based on the mechanism of light fluxes waveguide-resonant propagation.</p>