| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an ATM communication path ISDN public network bypass system that reduces the communication cost. SOLUTION: When an ATM communication unit 100-1 uses a backup line 20 by an ISDN public network to apply bypass connection to an ATM communication path due to a fault of a leased relay line 10 between the ATM communication unit 100-1 and an ATM communication unit 100-2, the ATM communication unit 100-1 subtracts a band used for the ATM communication path from the available band of the backup line 20. When the band is deficient as a result, a communication channel of the ISDN public network for the required band is additionally connected. Furthermore, when the ATM communication path on the backup line is interrupted, the band of the ATM communication path interrupted on the backup line is added to the available band and when the band by one communication channel of the ISDN public network or over is idle, the channel is open.</p> |
