The paper presents and compares various unicast non-blocking architectures to be used into space-domain photonic switching networks. All the analyzed architectures have been evaluated and compared considering a possible physical implementation based on guided-wave structures realized with integrated optics technology. Some properties including number of switching elements required, blocking performance, number of waveguide crossovers, system attenuation, and signal-to-noise ratio are evaluated and analyzed. The main purpose of this work is to review the state-of-the-art of optical guided-wave space-switching architectures and to provide a relevant set of technical elements useful in the selection of architectures to be used in all-optical cross-connect implementation.