According to one embodiment, a server includes a control unit which instructs establishment and end of connection for the video data communications between the client computers corresponding to the telephone terminals, in accordance with the call information event received by the call information event receiving unit, and a connection information transmitting unit which transmits connection information between the plurality of client computers for which one of the establishment and the end of connection is executed by the control unit, wherein even if the connection information transmitting unit receives a notification of completion or end of the connection from the client computers, when the connection information transmitting unit receives a notification which accompanies change of connection states of the client computers, the connection information transmitting unit transmits the connection information after waiting for the change of the connection states.