Patent ID: 7746775

Claim:
An instant service method for servicing packets in deficit-round-robin (DRR) data packet scheduling, the method comprising: servicing a current flow according to packet scheduling of a current round; activating a new flow according to an input of a new data packet; if the current flow is not the last flow scheduled to be serviced in the current round, servicing the new flow immediately when the current flow service is completed; and servicing a next flow after the new flow service is completed, wherein each of the servicing the current flow, the servicing the new flow, and the servicing the next flow comprises: reading out information relating to a current packet pointer, a current flow pointer, a quanta value, a deficit value, and a current packet size of the flow to be serviced from a flow information storage; if the current packet size is smaller than or equal to a sum of the quanta value and the deficit value, forming and providing a corresponding data packet to be serviced; and if the current packet size is larger than the sum of the quanta value and the deficit value, storing the sum of the quanta value and the deficit value as a new deficit value, and servicing the flow on a next round, and wherein at least one of the servicing the current flow, the activating the new flow, the servicing the new flow, and the servicing the next flow, is performed by a tangible controller.