Patent ID: 6570848
Filing Date: 2003-05-27
Classification: H04L,H04Q

Abstract:
A network switch comprising:a port for the reception and transmission of data packets, and a receive buffer store connected to the port, means for detecting a predetermined state of fullness of the buffer store, means for initiating in response to the state of fullness, the production of control frames for signaling to at least a first source of said packets to pause the sending of packets to the switch, means for counting said frames to obtain a measure of congestion of the switch, and means responsive to a rate of change of said measure to enable the discarding of packets received by the buffer when said rate is higher than a first predetermined value and to disable the discarding of packets when the rate of change of the measure is below a second predetermined value; wherein said switch includes at least one other port and a transmit buffer associated with said port and wherein said switch causes said discarding of packets by causing packets to be transmitted across the switch from said receive buffer to said transmit buffer whereby said packets are discarded if said transmit buffer is full.