Activation of multiple xDSL modems with implicit channel probe

摘要

A communication apparatus that is selectively connectable to a communication device. A communicator executes a first communication mode to transmit a first predetermined signal to a communication device that designates a specific mode, and the communication device responds by issuing a second predetermined signal. The communicator executes a second communication mode to transmit a third predetermined signal to the communication device that requests a transmission of the first predetermined signal from the communication device, and upon receipt of the first predetermined signal from the communication device, transmits the second predetermined signal to the communication device. A controller controls the execution of either the first communication mode or the second communication mode upon initializing a communication with the communication device.