Patent ID: 7145918

Claim:
A bandwidth control device for a network switch having a plurality of client ports and at least one uplink port to switch packets among the client ports and the uplink port, each client port having a predefined bandwidth threshold, the bandwidth control device comprising: a first multiplier for multiplying a traffic rate TrΔ[n] of a client port in a time slot n by a first multiplicator g (g<1), where the time slot n is defined as a time interval from time t n to t n+1 , and the traffic rate represents length of transmitted packets; a second multiplier for multiplying an average traffic rate Tr[n] of the client port actually generated before time slot n and stored in a register by a second multiplicator 1−g; an adder for adding outputs from the first multiplier and the second multiplier, so as to obtain an average traffic rate of the client port before time slot n+1 as Tr[n+1]=g*TrΔ[n]+(1−g)*Tr[n]; the register provided for temporarily storing the average traffic rate Tr[n+1] of the client port generated before time slot n+1; and a comparator for comparing the average traffic rate Tr[n+1] of the client port generated before time slot n+1 and a bandwidth threshold Tr_pre of the client port, and if Tr[n+1] is smaller than Tr_pre, the client port being allowed to transmit packets.