A method of handling telephone signals supplied by an analog telephone set and data supplied by a data terminal in a subscriber line circuit of a digital telephone switching system used at least in subregions for data transmission includes directly connecting a telephone set and a data terminal with a modem to the digital telephone switching system through a common analog subscriber line, at least one of subjecting data supplied by the data terminal to a sampling operation at a sampling rate above a sampling rate required for telephone information during analog/digital conversion and coding sampling values representing data supplied by the data terminal according to a linear characteristic during analog/digital conversion, and feeding data originating from and handled by the data terminal directly to a data transmission network. A subscriber line circuit for handling telephone signals supplied by an analog telephone set and data supplied by a data terminal is also provided.