A modem which connects to a data terminal is connected to a telephone line capable of supporting multiple directory numbers with each number having a distinctive ring signal. The modem has a ring detector which indicates the presence of a ring signal associated with an incoming call from a remote device. The modem also includes a datapump unit capable of processing analog signals associated with a telephone line and digital data associated with the data terminal. A modem controller determines ring type from the ring signal of the incoming telephone call and alters the processing of the incoming telephone call based on the ring type. To that end, the controller may alter the processing of the incoming telephone call by configuring the datapump unit and/or configuring a controller compression/error-correction module based on the ring type before the incoming telephone call is answered. Further, the controller may direct the routing of the incoming telephone call via the data terminal based on the ring type.