Abstract: An input/output module for use in a communications system including a plurality of interface cells, with each cell including circuitry for interfacing with either an optical or an electrical transmission media. An optical or electrical media connector, as needed, is connected to the interface circuitry. The input/output module further includes an inter-module connector for connecting the interface circuitry of the module to other similar modules or other circuit boards in the communications system. The disclosed input/output module is especially useful in a communications switch where a plurality of input/output modules are interconnected to each other through a crosspoint module.