part then the spare bandwidth for the queue is reduced no weight update is necessary if the demand cannot be met spare bandwidth is extracted from all queues in equal proportion and a new weight is calculated for the queue when bandwidth is returned to a queue through a connection release the queue weight is not changed and the spare bandwidth for the queue is increased by the released bandwidth a feature of this algorithm is that spare bandwidth is allocated to queues which have most recently used that bandwidth this is an adaptive characteristic in which the switch converges to a spare bandwidth distribution which reflects actual demand the initialization of wfq control is performed by cac which configures the number of service queues the total free bandwidth to be shared by all service queues and the service type of each service queue real time or non real time the free bandwidth is distributed equally within the transient and steady state pools and the weights for all queues are downloaded to the arbiter driver fig2 illustrates this initialization fig3 illustrates the algorithm performed by wfq control when additional bandwidth is requested by cac in this figure ssspare i and trspare i represent respectively the steady state and transient spare bandwidth allocated to queue i sstnrt is the total bandwidth in the steady state pool allocated to non real time queues sssparetotal and trsparetotal are the total spare bandwidth in the steady state and transient pools respectively ssbw i and trbw i represent respectively the steady state and transient bandwidth allocated to queue.