| 摘要 |
PURPOSE: To quickly execute alternative operation at the occurrence of a fault. CONSTITUTION: At the time of setting up a connection, each ATM exchange sets up converting header information for a normal path in a line interface routing table 21 and sets up header information for a by-pass in an alternative routing table 25. Each line interface inspects the existence of a fault in an output line while referring to a bit map memory for storing a fault line and a fault VPI at the arrival of a cell, applies the header information stored in the table 21 when there is no fault or applies the header information stored in the table 25 when a fault exists in the output line to execute header conversion, and then outputs the cell to an ATM switch. Since an alternative route can be quickly selected when a fault exists in a network, the number of canceled cells due to the occurrence of a fault can be reduced, and even at the occurrence of a multiple fault, the alternative operation can be executed. |
