TRANSMISSION NODE AND NETWORK SYSTEM

PROBLEM TO BE SOLVED: To surely switch a faulty transmission line by suppressing the effects on traffic and a user band. SOLUTION: A transmission node is provided with a transmission line monitor section 42-1, an OAM cell monitoring section 42-5 that monitors an OAM cell and transmits a detected OAM cell as it is or transmits the cell after correcting the cell into a switching trigger cell, a switching trigger discriminating section 42-2 that discriminates presence of the necessity of transmission of the switching trigger cell, on the basis of fault information from the transmission line monitor section 42-1 and discriminates whether or not the OAM cell detected by the OAM cell monitoring section 42-5 is a switching trigger cell, a switching processing section 41 that applies switching processing to a transmission line when the switching trigger discrimination section 42-2 discriminates the switching trigger cell, and a switching trigger information insert section 42-3 that inserts information required for switching processing to the detected OAM cell or switching trigger cell to correct the cell.