Patent ID: 6501731
Filing Date: 2002-12-31
Classification: G06F,H04L

Abstract:
A network device, coupled to one or more networks, for shaping cell transmission traffic for a plurality of variable bit rate (VBR) and constant bit rate (CBR) virtual channels (VCs), the device comprising:a plurality of traffic shapers, wherein each shaper is connected to one of a plurality of clock sources, each clock source having a different clock cycle, wherein each shaper is capable of shaping traffic for CBR and VBR VCs, and wherein each shaper includes: a pointer to a first VC in a link list of one or more VCs; a first counter initialized to a first starting value, wherein the first counter is decremented continuously on each clock cycle of the associated clock source; and an arbitration counter; and a priority encoder, coupled to each of the plurality of arbitration counters, for determining transmission priority between the plurality of shapers; wherein, for each shaper, when the first counter is decremented to a value of zero, the arbitration counter is initialized to a second starting value and enabled for selection by the priority encoder, and wherein, for each shaper, the arbitration counter is decremented after a cell transmission time associated with the shaper; and wherein when one or more arbitration counters are enabled, the priority encoder selects for cell transmission the shaper that has the lowest value in its enabled arbitration counter.