Abstract: A flexible multiplexer enables a liberal grouping and distribution of time slots of digital multiplex signals on dedicated lines with increasing numbers of connection units on the subscriber side and the line side. The accommodation of the numerous voice/data and signaling multiplex signal lines between the connection units thereby causes increasing numbers of problems. A reduction of the multiplex signal lines occurs when all channel units in the connection units of the subscriber side and all connection units of the line side are no longer connected to each multiplex line, but groups of connection units of the subscriber side and all connection units of the line side are each respectively connected via an incoming and an outgoing voice/data multiplex signal line to a voice/data switching matrix network and are connected via an incoming and an outgoing signaling multiplex signal line to an signaling switching matrix network.