QUEUE CONTROL APPARATUS AND CONTROL METHOD THEREOF

PROBLEM TO BE SOLVED: To implement priority transfer control corresponding to priorities even with packets of a plurality of priorities mixed in a single queue. SOLUTION: When packets colored in a plurality of different colors based on transfer priorities are stored in a logic queue storage 11 and queued using a single queue by a priority control 31, in the case of packet flow-in, "flow-in packet length", "waiting packet sequence length" and "flow-in packet priority" are managed by a queue storage 21 for management for each priority, packets stored in the logic queue storage 11 are discarded and if packets to be discarded can not be secured from the stored packets, flow-in packets are discarded with a probability corresponding to the packets which can not be discarded. In particular, when discarding stored packets, a packet of a priority lower than that of the flow-in packet is targeted, stored packets are managed as a list for each priority, and all the packets in the queue are discarded sequentially from the lowest priority. COPYRIGHT: (C)2011,JPO&INPIT