US 7,321,594 B2
Router apparatus provided with output port circuit including storage unit, and method of controlling output port circuit of router apparatus
Koso Murakami, Osaka (Japan); Hideki Tode, Osaka (Japan); Kazuhiko Kinoshita, Osaka (Japan); and Katsuya Minami, Tokyo (Japan)
Assigned to Semiconductor Technology Academic Research Center, Kanagawa (Japan)
Filed on Dec. 17, 2003, as Appl. No. 10/736,984.
Claims priority of application No. P2002-365494 (JP), filed on Dec. 17, 2002.
Prior Publication US 2004/0179542 A1, Sep. 16, 2004
Int. Cl. H04L 12/28 (2006.01); H04L 12/56 (2006.01)
U.S. Cl. 370—412  [370/395.41; 370/468; 370/230] 21 Claims
OG exemplary drawing
 
1. An output port circuit of a router apparatus for routing and transmitting a packet received through an input port circuit to each of adjacent nodes through the output port circuit by a switch fabric circuit, each of flows being constituted by a plurality of continuous packets and belonging to either one of a bandwidth-guaranteed class and a best-effort class, said output port circuit comprising:
a storage unit for temporarily storing a packet to be transmitted; and
a controller for controlling storage and reading out of the packet into and from said storage unit,
wherein upon allocating a basic volume that is a criterion of a memory size which can be stored in said storage unit to each of the flows to which the packet to be transmitted belongs, said controller is configured to manage the basic volume of each flow of the packet belonging to the bandwidth-guaranteed class by individually allocating the basic volume by as much as the memory size required by each of the flows, and to manage the basic volume of each of the flows of the packets belonging to the best-effort class by collectively allocating the memory size obtained by subtracting a sum of each the basic volume allocated to said bandwidth-guaranteed class from an entire memory size of said storage unit,
wherein said controller is configured to calculate a product of a priority and a number of flows belonging to a class for the each best-effort class, calculates a total priority of the best-effort class by calculating a sum of the products for the number of best-effort classes, calculate a basic volume allocation ratio for the received packet by dividing the priority of the class to which the flow of the received packet belongs by said calculated total priority, and calculate the basic volume of the flow of the received packet by calculating the product of said calculated basic volume allocation ratio and the basic volume of the best-effort class.