Packet switch that converts variable length packets to fixed length packets and uses fewer qos categories in the input queues that in the outout queues

Abstract

To achieve QoS control, drop control and multicast control of a variable-length packet at high speed in small scale hardware, a packet divider divides a variable-length packet into fixed-length packets, and an input buffer section stores the divided fixed-length packets into queues by output lines and by QoS classes. A large number of QoS classes are mapped into only two kinds of classes including a guaranteed bandwidth class for which an assigned bandwidth is guaranteed and a best effort class for which a surplus bandwidth is allocated, thereby to achieve scheduling at the input side by an inter-line scheduler. An output buffer section assembles a variable-length packet from fixed-length packets that have been obtained by switching at a switch section in an output buffer section. A QoS control is performed based on a packet length.