Patent ID: 7333436

Claim:
A network device having bandwidth control functions to transport cells, comprising: (a) a cell buffer that stores received cells and outputs one of the stored cells each time a cell output request signal becomes active; (b) a cell count manager that provides a stored cell count indicating the number of cells stored in said cell buffer; (c) a leaky bucket controller that controls bandwidth usage at a source end by using a leaky bucket algorithm, comprising: a leaky bucket counter that calculates a leaky bucket (LB) count at predetermined cell slot intervals by adding an output rate parameter to a modified LB count, and by subtracting therefrom a full rate parameter if the cell output request signal is active, an upper limit calculator that determines an upper limit for the LB count, a count modifier that produces a new value of the modified LB count by limiting the LB count not to exceed the upper limit, and a comparator that activates an output timing signal when the modified LB count from the count modifier equals or exceeds an output reference value; and (d) a cell output enable logic that activates the cell output request signal when the output timing signal is active and when the stored cell count is one or more.