A multiplexer capable of automatically and dynamically selecting a correct or the best input out of a pre-configurable set of alternative inputs, based on the current status of the alternative inputs. An input status-sensitive, dynamic, M-by-M digital cross-connect can be formed out of an arrangement of M (an integer) instances of such input-controllable dynamic M:1 multiplexers. An application is an SDH/SONET cross-connect system that is able to perform a protection-switch for any number, up to all, of its output paths, simultaneously, if necessary, thereby enabling a short and deterministic latency for individual-path-granular protection-switch process for cross-connects of unlimited capacity. Another application is an SDH/SONET path that can be dynamically shared, even at a single time-slot granularity, among multiple path sources. Such a multi-source-bus configuration of an SDH/SONET path enables allocating network resources dynamically based on the real-time capacity demand patterns, thereby maximizing the network throughput for bursty data traffic.