PURPOSE: To avoid a trouble due to a phone call such as a mischievous phone call completely by providing an identification signal generating section sending an identification signal via a telephone line.

CONSTITUTION: A caller side equipment 10 consists of an identification request signal discrimination section 11 and an identification signal generating section 12. Thus, even if a call signal reaches by dialing from the caller, an identification signal sent from the caller side equipment 10 reaches the called party equipment and so long as the content is not a prescribed signal, since the acceptance of the incoming call is not allowed, an undesired call to the called subscriber is rejected entirely positively.