| 摘要 |
PURPOSE:To facilitate the fault detection of a cell switch by discriminating that a fault takes place if no maintenance cell is outputted to an output communication line toward the maintenance cell even if a predetermined time elapses. CONSTITUTION:When contention take place in a cell switch 20, cell abort takes place in the entrance of input cell handling means 201a-201d and it is guaranteed no cell abort takes place in the inside of the cell switch 20. Thus, the discrimination whether a path of cell passing in the inside of the cell switch 20 is interrupted or not is executed with an easy condition that no maintenance cell is outputted from the cell switch 20 even when the maintenance cell is inputted to the cell switch 20 and a predetermined time elapses. Thus, the fault detection of the cell switch 20 formed by the hardware is facilitated. |
