Patent ID: 7522525

Claim:
An ingress L2 switch comprising: a VLAN functional portion mapping a frame to a predetermined VLAN; a frame classifying portion assigning to the frame a first tag indicating a priority preset with respect to the frame; a policing portion comparing a detected transmission rate of the frame with a preset transmission rate, and assigning to the frame a second tag indicating whether or not the frame can be discarded, wherein the VLAN functional portion assigns to the frame a VLAN tag identifying the mapped VLAN; a switch fabric switching the frame based on the VLAN tag; and a shaper outputting the frame based on the priority indicated by the first tag and discarding the frame having congested based on the second tag, wherein the shaper includes: a plurality of queues, each of which corresponds to the priority and queues the frame based on the priority indicated by the first tag for each VLAN; a first scheduler taking out the queued frame based on the priority of the queue for each VLAN; and a second scheduler taking out the frame taken out by the first scheduler by a weighted round-robin method.