| 摘要 |
<p>PURPOSE:To reduce the load on each node control processor and to quicken informing operation by sending an actual communication packet back on trouble detection with a logical channel number obtained by adding a trouble flag to the logical channel number of a forward actual communication path. CONSTITUTION:If trouble occurs to a packet exchange 14, a transmission line corresponding part on the trouble side of a packet exchange 13 adds the trouble detection flag FG to the logical channel number LCN''' of the forward actual path 31 and sends the actual communication packet back to a backward actual path 32. Consequently, while an exchange 11 sets the actual paths with a forward incoming-side logical channel number LCN and an outgoing-side logical channel number LCN', the actual paths are set with a backward incoming-side logical channel number LCN'+FG and an outgoing-side logical channel number LCN+FG. An exchange 12 also makes similar settings. Consequently, a transmission-side terminal 21 is informed of the trouble with the logical channel number LCN+FG of the path 32. Then a call is released and another call is set to restart a communication.</p> |
