Patent ID: 7023799

Claim:
A traffic shaper for transferring variable-length packets received from a plurality of input ports to one output port while guaranteeing preliminarily designated minimum bandwidths, comprising: a plurality of buffer memories for temporarily storing the variable-length packets received from said input ports; a bandwidth controller for specifying a buffer memory from which a packet is to be read out; and a read controller for reading out a variable-length packet from a buffer memory specified by said bandwidth controller and transmitting the packet to said output port, said bandwidth controller comprising: a plurality of leaky bucket units prepared in correspondence with said buffer memories; a plurality of level deviation detectors each for outputting a numerical value indicative of a difference between a level count value output from each of said leaky bucket units and a threshold corresponding to the preliminarily designated minimum guaranteed bandwidth; and an output queue designation unit for specifying a buffer memory from which a packet is to be read out on the basis of the difference values output from said level deviation detectors, and each of said leaky bucket units comprising: a level counter for decrementing the count value at a predetermined rate; and level raising means for increasing the count value of said level counter, in response to reading out of a packet from a corresponding buffer memory by said read controller, by a value proportional to the length of said packet.