In an automation-communication network, at least one distribution node comprises input/output interfaces each connected to at least one network segment. In a first network segment a first subscriber and in a second network segment a second subscriber are arranged. Data are exchanged between the first and the second subscriber by telegrams realized as scheduled telegrams and unscheduled telegrams. The distribution node receives an unscheduled telegram on an input/output interface and sends an unscheduled telegram on a further input/output interface. The distribution node determines a transmission duration for transmission of the unscheduled telegram. The distribution node transmits the unscheduled telegram. Prior to transmission, the distribution node deposits a first telegram information in a data field. The distribution node fragments the unscheduled telegram if the telegram cannot be transmitted within a time slot. Prior to transmission of the unscheduled telegram, the distribution node enters a second telegram information into the data field.