Abstract: A data communication control apparatus for use in association with a facsimile transmission device, comprising: a memory for storage of telephone number data, private network protocol information and telephone line communicable data; an off-hook detector for determining when the facsimile device is placing an outgoing call; a controller for controlling the outgoing call in response to an instruction from the off-hook detector, the controller comparing the number of the outgoing call with the telephone number data in the memory and determining whether that number is served by the private network; and a fax-tone detector in association with the off-hook detector and memory for determining the time-out parameter of the facsimile device placing the outgoing call; wherein when the outgoing call is placed by the facsimile device, the off-hook detector instructs the controller which first determines whether or not the outgoing call is a long distance number and, if so, whether the long distance area code is serviced