The communication network system

A communication network system (100) in which a plurality of communication stations (10, 20, 30) are connected to each other so as to send or receive messages. The communication network system is characterized in that each of the communication stations is provided with at least one processing unit, and, in the case in which a request message containing a command to measure a transient transmission process time has been received, the processing unit stores in storing means provided to the processing unit a first time required by the processing unit to process the request message, and sends out the request message; and, in the case in which a response message, which is a response to the request message containing the command to measure the transient transmission process time, has been received, the processing unit stores in the storing means a second time required until the response message is received after the request message is sent, and also stores a third time required by the processing unit to process the response message, and sends out the response message.