| 摘要 |
<p>PURPOSE:To bypass a call simply without interrupting the communication even when a fault takes place in a relay line by providing a bypass table to each packet exchange and revising path information in a packet according to the bypass table when a fault takes place in a call during communication passing through a relay line. CONSTITUTION:Each of packet exchanges 1a-1d is provided with a bypass table (6a-6d) representing the correspondence between a current path number and a bypass number to be replaced therewith. When a fault takes place in relay lines 2a-2e designated by path information of packets 5a, 5b to be relayed, the current path number of a packet is replaced with a bypass number obtained by referencing the bypass table (6a-6d) and routing is implemented based on the path number. Thus, communication is not interrupted even in the occurrence of a relay line fault during communication and the call is simply bypassed.</p> |
