A switching node for use in connection with a computer network includes an input interface, a buffer and a control element. The input interface receives cells from at least one input communication link. The buffer buffers selected cells prior to transmission over at least one output communication link. The control element selectively enables cells received by the input interface to be buffered in the buffer. The control element discards cells if the cell occupancy of the buffer exceeds a predetermined threshold level and a credit value indicates that the switching node has loaded a number of cells into the buffer for transmission which exceeds a cell loss ratio guarantee provided by the switching node.