| 摘要 |
PURPOSE:To prevent data transmission time from being prolonged by detecting whether or not congestion is occurred in a packet exchange network based on difference between the transmission time of the communication telegraphic message of a communication equipment and the reception time of the communication message of the other equipment and selecting either a packet exchange system or a line exchange system corresponding to the result. CONSTITUTION:For the communication message in the packet exchange system due to a packet communication equipment 3, the transmission time data of the communication message is included by a time data generator 5. When the difference between the transmission time data contained in the communication message and the reception time exceeds prescribed time, the data communication equipment receiving this communication message transmits a down telegraphic message while switching the system to the line system due to a line communication equipment 4. Therefore, when the congestion is generated in the packet network of a public telephone network 2 and the time from the transmission of the up communication message from one data communication equipment 1 to the reception at the other data communication equipment 1 is prolonged, the transmission/reception of the communication message is changed form the packet exchange system to the line exchange system. |
