Visual communication server, visual communication program and visual communication method

摘要

A VC server 1 has a call management unit 14 which detects a line connection state of telephone terminals based on an event signal received from an exchange 3 and registers the line connection state in a call information DB 11, a client information DB 10 in which telephone numbers of the telephone terminals and IDs of VC clients are stored in correspondence, a client connection information DB 12 in which session states between VC clients are stored, and a client session controller 15 which, when a change in line state between the telephone terminals is detected in the call information DB 11, refers to the client information DB 10, specifies a pair of corresponding VC clients, and instructs to establish or terminate a session between the VC clients according to the change in line state.