| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent failure in switching control by efficiently performing channel selection by applying a device number specific to each device. SOLUTION: When this digital switchboard 1a is started, this digital switchboard 1a and an adjacent opposite device 1b transfer the device number of each device through the Dch of a digital network I/F part 11, so that the master and slave relation between the adjacent devices can be preliminarily decided. At that point of time, even when call requests from respective telephone terminals 16a-16d and a call request from the opposite device 1b are issued, and those respective messages collide, an other channel selecting method is used between the digital switchboard 1a and the adjacent opposite device 1b based on master and slave relation between those devices. Therefore, when each call request is issued, channels to be selected by a channel managing part 13 can be made different, and the selection of the channels to be used can be efficiently performed.</p> |
