A packet communication method of facilitating packet communication between nodes in a network, comprising: - selecting one of a working communication path connected by two switching nodes (101, 102) via nodes (103, 104, 105); - selecting one of a backup communication path connected by the two switching nodes (101, 102) via backup nodes (106, 107, 108), the backup nodes (106, 107, 108) being nodes other than the switching nodes (101, 102) included in the backup communication path; - transmitting first traffic between the two switching nodes (101, 102) via the selected communication path; - causing the two switching nodes (101, 102) to select the working communication path as a communication path through which the first traffic passes when the working communication path operates under normal conditions, and to select the backup communication path as a communication path through which the first traffic passes when a failure occurs in the working communication path; characterized in that the method further comprises: - transmitting a switching control packet between the two switching nodes (101, 102) via the backup communication path, the switching control packet including working communication path identification information representing whether the first traffic passes through the working communication path; - causing the backup nodes (106, 107, 108) included in the backup communication path to determine whether the first traffic passes through the working communication path on the basis of the working communication path identification information included in the switching control packet; and - causing one of the backup nodes (106, 107, 108) to receive second traffic from the outside of the backup communication path,the second traffic being different from the first traffic, and to transmit the received second traffic to other backup node(s) (106, 107, 108) when the first traffic passes through the working communication path. - selecting one of a working communication path connected by two switching nodes (101, 102) via nodes (103, 104, 105); - selecting one of a backup communication path connected by the two switching nodes (101, 102) via backup nodes (106, 107, 108), the backup nodes (106, 107, 108) being nodes other than the switching nodes (101, 102) included in the backup communication path; - transmitting first traffic between the two switching nodes (101, 102) via the selected communication path; - causing the two switching nodes (101, 102) to select the working communication path as a communication path through which the first traffic passes when the working communication path operates under normal conditions, and to select the backup communication path as a communication path through which the first traffic passes when a failure occurs in the working communication path; - transmitting a switching control packet between the two switching nodes (101, 102) via the backup communication path, the switching control packet including working communication path identification information representing whether the first traffic passes through the working communication path; - causing the backup nodes (106, 107, 108) included in the backup communication path to determine whether the first traffic passes through the working communication path on the basis of the working communication path identification information included in the switching control packet; and - causing one of the backup nodes (106, 107, 108) to receive second traffic from the outside of the backup communication path,the second traffic being different from the first traffic, and to transmit the received second traffic to other backup node(s) (106, 107, 108) when the first traffic passes through the working communication path.