| 摘要 |
<p>PURPOSE:To avoid the increase in the operating load of a processor by counting number of times of detection when the reception of an illegal packet is detected and closing the line as the counted value reaches a prescribed value for a prescribed time. CONSTITUTION:When illegal packets P1-P5, P1', P2' arrive from lines t2, t3, a monitoring section A detect them and number of times of reception count is registered at every lines t2, t3 and when each counted value is increased from an initial value '0' to '1', a timer B provided on each line is started. When it expires and the counted value reaches a prescribed value till a prescribed time elapses, the line t2 has a high error occurrence frequency and is discriminated to be an improper line, a processor PC1 sends a carrier stop command(CSP) to the line t2 to close the line t2. Thus, the station PS4 selects a bypass path via the lines t4, t5 in response to the reception of the CSP, thereby switching the line having less error occurrence frequency in itself.</p> |
