BUFFERING OF POINT-TO-POINT AND/OR POINT-TO-MULTIPOINT ATM CELLS

摘要

An Asynchronous Transfer Mode (ATM) switching device (20) has ATM cells (both point-to-point and point-to-multipoint) routed therethrough to one or more physical output links (31 - 38). The switching device (20) includes a cell buffer memory (92) which is the sole storage area on an egress exchange terminal for all cells, including point-to-multipoint cells, regardless of to which physical output link the cell is destinated. For point-to-multipoint cells, pointers to the location of the cell in the cell buffer memory (92) are stored in one or more pointer queues (114), the pointer queues (114) corresponding to physical output links over which the point-to-multipoint cells are expected to be propagated. As each physical output link is selected, the pointer in the corresponding pointer queue is used to obtain the cell from the cell buffer memory (92) for readout on the selected link.