Abstract: When a telephone a belonging to an office a calls up a telephone b belonging to an office b, a subscriber of the telephone a operates a WS a connected to a computer network and edits camp-on request information when the telephone b is busy. The camp-on request information is transferred from the WS a to a CTI server b belonging to the office b connected to the computer network. The CTI server unit b performs camp-on control between the telephone b belonging to the office b and the telephone a belonging to the office a by controlling a private branch exchange b based on a schedule corresponding to the received camp-on request information.

Abstract: When a telephone a belonging to an office a calls up a telephone b belonging to an office b, a subscriber of the telephone a operates a WS a connected to a computer network and edits camp-on request information when the telephone b is busy. The camp-on request information is transferred from the WS a to a CTI server b belonging to the office b connected to the computer network. The CTI server unit b performs camp-on control between the telephone b belonging to the office b and the telephone a belonging to the office a by controlling a private branch exchange b based on a schedule corresponding to the received camp-on request information.

Abstract: When a telephone a belonging to an office a calls up a telephone b belonging to an office b, a subscriber of the telephone a operates a WS a connected to a computer network and edits camp-on request information when the telephone b is busy. The camp-on request information is transferred from the WS a to a CTI server b belonging to the office b connected to the computer network. The CTI server unit b performs camp-on control between the telephone b belonging to the office b and the telephone a belonging to the office a by controlling a private branch exchange b based on a schedule corresponding to the received camp-on request information.

Abstract: A LAN-to-LAN connecting unit sends a node-status confirmation packet PKTC to LAN terminals under its command to confirm the status of each terminal. Upon receiving the confirmation packet, a normal terminal sends a response packet PKTR back to the LAN-to-LAN connecting unit. However, a LAN terminal incapable of receiving data because of a pulled cable or some other problem cannot send back the response packet. The LAN-to-LAN connecting unit identifies and stores information indicating whether a LAN terminal is capable or incapable of reception depending upon whether the response packet is received. In a case where an incoming call has been terminated at a prescribed LAN terminal and this terminal is capable of reception, the LAN-to-LAN connecting unit receives the data sent from the other party's LAN terminal and transmits this data to the LAN. In a case where the prescribed LAN terminal is incapable of reception, the connecting unit disconnects the line immediately.