| 摘要 |
<p>PURPOSE:To immediately switch a defective using route to another set route at the failure of the using route and to continue data transfer by previously setting up a logical channel also in a stand-by route similarly to a main route at the setting of a call. CONSTITUTION:It is supposed that a fault is generated in a circuit between a PS 15 and a PS 16 when a logical channel with a logical channel No. LCN#0 is using a route #0. At that time, fault information is transmitted to a point, e.g. the PS 15, branched from other routes out of exchanges on the route #0 of the LCN#0. Thereby, the PS 15 selects a route #1 to avert the defective circuit. In this case, the using route can be switched to the set route #1 only by updating PN in a using route table. When a data packet of the LCN#0 is received, the data packet may be sent to the output route, i.e. a PS 17, of PN#1 by using two tables. Although data transfer is interrupted at the PS 15 during the period, an originating terminal can continue data transfer.</p> |
