Cell scheduling method of input and output buffered switch using simple iterative matching algorithm

Abstract

A method for scheduling an input and output buffered ATM or packet switch and, more particularly, to a method for cell-scheduling an input and output buffered switch that is adapted to a high-speed large switch is provided. The input and output buffered switch has multiple switching planes, and its structure is used to compensated for decreasing performance of the input buffered switch resulting from HOL (head-of-line) blocking of the input buffered switch. The input and output buffered switch consists of input buffer modules grouping several input ports and output ports and output buffer modules, and each input buffer module has several FIFO queues for the associated module output buffer modules. In the input and output buffered switch having multiple switching planes, cell scheduling is carried out using a simple iterative matching (SIM) method. The SIM method consists of three operations, those are, request operation, grant operation, and accepting operation, and in the SIM method, the operations are iteratively carried out several times in one cell period, thereby matching efficiency can be increased. Each input buffered module determines simultaneously multiple FIFO queues served in one cell period, so that the SIM method with multiple selection ability has higher speed operations and better performance than conventional scheduling methods.