Abstract: The network access node of a digital communication system for the bidirectional transmission of message signals between, for example, a switching center and subscribers as an electrically switchable connection between the lines to the switching centers with a first interface and the lines to the subscribers with a second interface. The first interface is preferably an interface for a time-division multiplex signal with a transmission rate of 2 Mbit/s; the second interface is preferably an interface for signals in multiple access with time-division multiplex (TDM/TDMA). The buffer memory of the TDM/TDMA system is made up of partial memories arranged as a matrix. The partial memories are used simultaneously as a buffer memory for the circuit of the paths.