Abstract: Disclosed is a switching system for pooling a predetermined number of pairs of individual voice and individual data signal lines to serve on a demand basis a greater number of lines that simultaneously transfer voice and data signals. Each pair of lines includes a line for transferring a voice signal and another line for transferring a data signal. The switching system includes a plurality of interface units each coupled to a pair of lines for transferring a voice signal between the individual voice signal line in the coupled pair of lines and a simultaneous voice and data signals line interconnected with the interface unit. Each unit also transfers a data signal between the individual data signal line in the coupled pair and the interconnected simultaneous voice and data signals line. The switching system also includes a switching network for interconnecting an interface unit and a simultaneous voice and data signals line requesting service.