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US 6,721,324 B1Granted
Switch control system in ATM switching system
AssigneeNEC Corporation
InventorMasayuki Shinohara
Life of this patent
Estimating the term…
Abstract
In candidate selection to select the queue issuing the connection request to a certain output port out of a plurality of logic queues provided in an input buffer section of an input buffer type ATM switching system to store cells for each output port and each connection, whether a logic queue holds cells in predetermined order is checked, and the logic queue located next to the queue to which gained the right to connect to an output port last time is taken as a start point of the rotation priority control to select the logic queue holding the cell searched first.
Claims14
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.
5 more elements
An ATM switch comprising:
- an input buffer section installed for each of two or more input ports;
- an arbiter section that determines to which input port an output port connection right will be given, and which cross point of a crossbar type switch is to be turned on or off;
- a switch exchange that exchanges an ATM cell between an input port and an output port;
- and
- two or more logical queues, wherein a first logical queue is located next to a second logical queue, said second logical being the last logical queue to have obtained an output port connection right, and said first logical queue being taken as a start point of rotation priority selection control, said rotation priority control searching sequentially in a predetermined order to find which of the logical queues holds a predetermined number of cells, and selecting the first logical queue found to hold the predetermined number of cells, in a candidate selection process that selects one or more logical queues that are eligible to obtain an output port connection right.
2 more elements
Dependencies are inferred from the claim text.