Abstract: Telephone network comprised of a plurality of nodes which are coupled to each other by means of transmission lines, each node comprising a switching module, a central module and at least one peripheral module and an operational maintenance control unit, which can supply a command consisting of a sequence of sub-commands for changing the data in one or more nodes in the network being coupled to one of the nodes, there being coupled to one of the nodes a central back-up memory containing a network register for the sub-commands which are common to all the nodes of the network, local registers for specific sub-commands for always one node, one local register being provided for each node, and also a sequence number Table from which a unique sequence number can be assigned to each sub-command intended for storage either in the network register or in one of the local registers and a last relevant sequence number Table of the sub-command last registered for each of the node units being included, the sub-commands bein