Abstract: The invention provides for simultaneous local area networking and analog telephony using a single telephone line. The local area networking is carried out using two or more high-frequency modems, which when coupled to devices, can transfer data on high-frequency signals. These high-frequency signals may be carried on the telephone line along with the lower frequency signals used for analog telephony provided there is proper isolation. Thus, the invention utilizes selectively high-frequency bandpass and audio frequency bandpass filters coupled to the telephone line.