PACKET COMMUNICATION SYSTEM AND ATM EXCHANGE

摘要

PROBLEM TO BE SOLVED: To minimize the high load state of an ATM network by preferentially outputting an ATM cell inputted from a specified input port in the case that the transmission waiting time of an already transmitted high transmission priority ATM cell is long when no more high transmission priority ATM cell to be preferentially outputted is present and a low transmission priority ATM cell is to be transmitted. SOLUTION: This ATM exchange 1 stores the received ATM cells in an ATM cell storage buffer part 12 and preferentially outputs the high transmission priority ATM cells. In the case that no more high transmission priority ATM cell is present and information for indicating that the transmission waiting time of the high transmission priority ATM cell is long is stored in a transmission state detection/information storage part 15, the ATM cells inputted through the input port in an order for the input ports #1-#3 within the low transmission priority ATM waiting for output are preferentially outputted. Thus, retransmission by the time-out of packet constitution time at a transmission destination is minimized and the loads of a communication channel are suppressed.