A method and arrangement for transferring synchronizing information in a data transmission system includes modem connections. The arrangement includes a modulator (207) arranged to generate an analog signal (222) modulated by synchronizing information, the frequency spectrum of the signal being located in a frequency range that falls outside the data transmission bands of the modem line connected to the network element. The arrangement includes a switching circuit (208) arranged to connect the analog signal to a data transmission cable (206) that forms part of the modem line connected to a network element. The arrangement includes a second switching circuit (209) arranged to receive the analog signal from a data transmission cable that forms part of the modem line connected to the second network element. The arrangement also includes a regenerator (209-arranged to regenerate the synchronizing information from the analog signal.