To provide a network switch for eliminating inconveniences where a port having much amount of transmission of frames can transmit many frames in congestion.
A frame discrimination section 11 discriminates the priority of a received frame and accumulates the frame in queues Q0-Q3 for each priority according to the discrimination result. A memory monitor 22 obtains the total capacity of frames accumulated in the queues Q0-Q3 of queue managements 10-1 to 10-N, and instructs an abort section 23 to abort frames starting from those corresponding to a queue in which the priority of a port having a high occupancy rate of a buffer memory 21 is low, when the total capacity of frames reaches a threshold, thus preventing the frame transmission of a port having a low occupancy rate of the buffer memory 21 from being blocked.
Toshio Morita
Yoshihei Nakamura
Yutaka Horii
Hisato Noda
Masayuki Sakai