METHOD FOR REDUCING LOCAL/EXTENSION PORT WRONG OPERATIONS IN AN IP-BASED KEYPHONE SYSTEM, PARTICULARLY CORRELATED TO MINIMIZING THE WRONG OPERATIONS EVEN THOUGH A PACKET TRANSMITTED TO INFORM OF STATE CHANGES OF EACH GATEWAY IS LOST

摘要

PURPOSE: A method for reducing local/extension port wrong operations in an IP-based keyphone system is provided to minimize the probability of wrong operations caused when local and extension access gateways wrongly recognize mutual states owing to packet loss, thereby increasing the stability of a keyphone system. CONSTITUTION: A main control gateway transmits an access confirm request signal to local/extension access gateways. The local/extension access gateways transmit an access confirm response signal including information on current states of each port to the main control gateway. The main control gateway compares the information on each port state with information on each port state of the local/extension access gateways stored in a self memory, and corrects each port state stored in the self memory if the compared information is not identical.