How transparent the future all-optical packet switched network should be?

"Transparent network" and "all-optical network" are not synonyms. Indeed, the optical transparency has to be sacrificed in optical logic elements, signal processing, packet switching, etc. As a consequence, the traditional "electronic opacity" meets its "optical" equivalent in all-optical packet switched network. The paper presents the author's original view on future (all) optical packet-switched network which is based on a clear distinction within the dual nature of optical signals: analogue and transparent features of the signal in optical frequency domain from one side, and the digital characteristics of temporal signals and opaque solutions for all-optical logic from the other one. The imminence of breakdown of the "transparency paradigm" in the all-optical packet switched network for a variety of networking functions is pointed out.