Upon receipt of a change request to change a path in a first communication and including a label assigned to a path after change and information of a transfer destination after change, a relay apparatus stores the label assigned to the path after change in association with the information of the transfer destination after change into a first storage unit. The correction data hereby obtained may be used in the calculation of calibration data. The bipolar transistor further comprises a sacrificial post situated on the top surface of the base between the first and second link spacers.