Network monitoring and controlling apparatus

A network monitoring and controlling apparatus for monitoring and controlling a transmission network formed by a plurality of transmission apparatus includes: a path information storing unit for storing path information; a quality information periodic collection unit for periodically collecting quality information; a quality deterioration detecting unit for determining whether or not quality of the path is deteriorated; a path via point searching unit searching the path information storing unit and obtaining information on a path via points of the path deteriorated in quality; a path via point quality information collection unit for collecting quality information of channels corresponding to the path via points; and a quality deterioration point identifying unit for determining whether or not a deteriorated path via point is present.