When a communication path between a user site and a dual-homed data center is made redundant, a communication between the user site and a server within a data center can be continued. An edge node DCE-1 of a data center 40-1 and edge nodes TPE-1, TPE-2 of a transport network are connected to each other by a link TPE-1-1 and a link TPE-2-1, respectively. The edge nodes TPE-3 and TPE-1, TPE-2 that hold a node AE51 of a user site 50 are set with an LSP 110 of an active system, and an LSP 120 of a backup system, respectively. One of the links is active, and the other link is backup, and the LSP of the TPE node having the active link in the LSP 100 and the LSP 120 is made active. The respective links are prioritized, and the links are switched to an active state in order from the links higher in the order of priority when a link failure or an LSP failure occurs.