| 摘要 |
<p>A client terminal arranged at one location "a" is contained in an edge node (gateway) having a redundant configuration formed by a main system and an auxiliary system. In a normal mode, the edge node PE A of the main system is used to enable communication with a partner client terminal at locations "b" and "c" via opposing edge nodes PE B and PE C. Moreover, in the normal mode, a database containing information on a label used by the main edge node is synchronized with a database of the auxiliary system edge node. Moreover, the edge node of the auxiliary system stores a loopback address of the main system and disables it. When the edge node of the main system has failed, the loopback address of the main system edge node is enabled by the auxiliary system edge node. By using the information stored in the database containing the label information used by the main system, the auxiliary system edge node resumes communication with the opposing edge node by using the same label as the main system edge node.</p> |
