Recognition manner and ISDN network response mode and ISDN terminal unit null of

摘要

PURPOSE:To prevent a result in which an opponent is made awaited from occurring by judging a state that a terminal designated by a sub address is set at an unresponsible state at the time of receiving a call setting message again by the time-out of a response awaiting timer for the sending of the call setting message at a network side. CONSTITUTION:When the call setting messages 151 and 152 are received in idling time, a processing is shifted to an incoming call processing when its own terminal is not designated, and regular control is completed. When the sub address is not addressed to its own, the content of an area 154 for substitution response flag in a RAM 150 is checked, and when no flag is set, a state is recovered to an idling state, then, is set at a standby state. When the substitution response flag is set, buffers 151 and 152 for call setting message in a RAM 150 are checked, and it is judged whether or not the same message exists. When no same message exists, the message is stored in the air buffers of the buffers 151 and 152, then, a timer 140 is started.