Patent ID: 6721324
Filing Date: 2004-04-13
Classification: H04L,H04Q

Abstract:
An ATM switching system comprising:two or more input ports; an output port; an input buffer section corresponding to each input port, said input buffer section including a logical queue, the logical queue corresponding to the output port; an arbiter section that determines to which input port an output port connection right is given; a crossbar type switch through which an ATM (asynchronous transfer mode) cell is exchanged between the input ports and the output port; a candidate selection processing unit that performs a candidate selection process that determines which of the logical queues issuing a connection request will be given the output port connection right, the candidate selection process including searching the logical queues in a first predetermined order for a logical queue that holds a predetermined number of cells, the search beginning with a first logical queue located next in the first predetermined order to a second logical queue, said second logical queue being the last logical queue to have obtained an output port connection right, and selecting the logical queue first found to hold the predetermined number of cells; and a competition arbitration processing unit that performs a competition arbitration process that determines which of the input ports issuing a connection request will be given an output port connection right when two or more of the input ports are selected during the candidate selection process to connect to the same output port at the same time the competition arbitration process including searching the input ports in a second predetermined order for the input port belonging to the highest priority class, the search beginning with a first input port located next in the second predetermined order to a second input port, said second input port being the last input port to have obtained an output port connection right, and selecting the input port belonging to the highest priority class.