System for providing automatic voice messaging in a digital network environment

A line interface unit for controlling receipt and delivery of voice messages over a telephone system having a voice message facility, the voice message facility connectable to at least one calling station and a called station and normally having access prevention means for preventing storage and forwarding of voice messages unless predetermined access codes are received and verified by the access prevention means, the calling station connected to a central office, the line interface unit comprising:

• a switch connected to the central office and having first and second positions and wherein signals are connected directly between the calling station and the central office when the switch is in the first position;
• means for signaling the voice message facility;
• means for monitoring call progress upon call initiation to the called station;
• means connected to the monitoring means for detecting a predetermined condition at the called station upon call initiation to the called station, for detecting receipt of a first predetermined code from the calling station indicating that the caller desires to leave a voice message for the called station at the caller's expense, and for detecting receipt of a second predetermined code from the voice message facility;
• and
• control means connected to the detecting means and the switch, the control means responsive to receipt of the first predetermined code from the calling station for switching the switch from its first position to its second position to enable the signaling means to signal the voice message facility;
• wherein after signaling the voice message facility, the control means is responsive to receipt of the second predetermined code from the voice message facility for switching the switch from its second position back to its first position to connect the calling station to the voice message facility.

A method, using a line interface unit, for controlling receipt and delivery of voice messages over a telephone system having a voice message facility connectable to at least one calling station and a called station via acentral office, the voice message facility normally having access prevention means for preventing storage of voice messages unless predetermined access codes are received and verified by the access prevention means, wherein the line interface unit includes a monitor circuit for monitoring tip and ring lines of the calling station, a speech circuit for issuing a predetermined prompt to a caller at the calling station, a signaling circuit for signaling the voice message facility, a detector circuit connected to the monitor circuit for detecting signals on the tip and ring lines and a control circuit for controlling the operation of the line interface unit, the method comprising the steps of:

• determining whether a predetermined condition exists at the called station upon call initiation to the called station;
• if the predetermined condition exists, connecting the speech circuit to the calling station to thereby enable the speech circuit to issue the prompt;
• activating the speech circuit to issue the prompt to the caller at the calling station;
• determining whether a predetermined code has been received from the calling station, indicating that the caller desires to leave a voice message for the called station;
• if the predetermined code has been received from the calling station, connecting the signaling circuit to the central office to thereby enable the signaling circuit to signal the voice message facility;
• and
• activating the signaling circuit to signal the voice message facility.

A method, using a line interface unit, for controlling receipt and delivery of voice messages over a telephone system having a voice message facility connectable to at least one calling station and a called station via a central office, the line interface unit including a monitor circuit from monitoring tip and ring lines of the calling station, a speech circuit for issuing a predetermined prompt to a caller at the calling station, a signaling circuit for signaling the voice message facility, a detector circuit for detecting signals on the tip and ring lines and a control circuit for controlling the operation of the line interface unit, the method comprising the steps of:

• determining whether a busy or ring/no answer condition exists at the called station upon call initiation to the called station;
• if a busy or ring/no answer condition exists, connecting the speech circuit to the calling station to thereby enable the speech circuit to issue the prompt;
• activating the speech circuit to issue the prompt to the caller at the calling station;
• determining whether a predetermined code has been received from the calling station, indicating that the caller desires to leave a voice message for the called station;
• if the predetermined code has been received from the calling station, connecting the signaling circuit to the central office to thereby enable the signaling circuit to signal the voice message facility;
• and
• activating the signaling circuit to signal the voice message facility.