Abstract: The invention relates to a method and a system for the transferring of packet-switched information in a telecommunication system which comprises a router (R) to which an optical cable (LC) is connected that consists of optical fibres (LF) to which two wavelengths of light are sent and which is connected to the telecommunication network (CN), in which method, at the router (R), the piece of address information is received from the address wavelength (AWL) of the optical fibre (LF); and the payload information is received at the router (R) from the payload wavelength (DWL) of the optical fibre (LF). In the method, the payload wavelength (DWL) is routed based on the received piece of address information.