PURPOSE: To reduce the number of cells to be abandoned by duplication of destinations by providing switching network circuits, which subjecting cells outputted from input cell buffers to routing processing to send them to destinations, to perform processing of the cells having the same destination by different circuits.
CONSTITUTION: Input cell buffers 10 to 13 where cells inputted from incoming lines are temporarily stored and output cell buffers 15 to 18 which control transmission of cells to outgoing lines are provided. Switching network circuits 23 and 24 which send sells, which are outputted from buffers 10 to 13, to buffers 15 to 18 for destinations of cells by prescribed routing processing and cell selectors S0 and S3 which select the circuits 23 and 24 are provided. A cell contention circuit 25 selects the cell to be out putted to the circuit 23 or 24 from cells in buffers 10 to 13 so that cells contending for a destination are not outputted to the same circuit 23 or 24. Outputs of circuits 23 and 24 are multiplexed and outputted with respect to each destination, Thus, the line use ratio of incoming lines is improved to reduce the number of cells to be abandoned.
SHIRAISHI OSAMU
NOIRI AKIRA
