| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling a line so as to be capable of implementing a reliable call using an IP line with high line utilization efficiency at a low cost. ! SOLUTION: An IP line control method for performing transmission/reception between a general telephone set and an IP telephone terminal through a switch and a plurality of lines includes: transmission/reception of voice data using any one line of the plurality of lines after a termination of a call connection procedure between a device on the transmission side (transmission side device) and a device on the reception side (reception side device); a control unit of the transmission side device adding other lines of the plurality of lines, when detecting reduction in voice quality during the transmission/reception, to simultaneously transmit/receive the same voice data between the devices by using a plurality of lines; and the control unit of the transmission side device successively excluding lines from the added lines unt |
