Voice messaging system with ability to prevent hung calls

• US 6,608,887 B1
• Filed: 11/30/1999
• Issued: 08/19/2003
• Est. Priority Date: 11/30/1999
• Status: Expired due to Term

• Current Assignee: Unisys Corporation
• Original Assignee: Unisys Corporation
• Inventors: Davis, Jonathan Paul, Reksten, Harald Samuel
• Primary Examiner(s): Hoosain, Allan
• Application Number:
  US09/451,077
• Time in Patent Office: 1,358 Days
• Field of Search: 379/67.1, 379/81, 379/88.07, 379/88.22, 379/88.25, 379/88.08, 379/93.31, 379/100.05, 379/72, 379/73, 379/84, 379/88.04, 379/88.12, 379/88.13, 379/88.14, 379/88.17, 379/88.18, 379/88.19, 379/88.2, 379/88.21, 379/93.35
• US Class Current: 379/67.1
• CPC Class Codes: H04M 3/12 Marking faulty circuits "busy"; Enabling equipment to disengage itself from faulty circuits ; Using redundant circuits; Response of a circuit, apparatus or system to an error
• CPC Class Codes: H04M 3/16 with lock-out or secrecy provision in party-line systems
• CPC Class Codes: H04M 3/533 Voice mail systems

Abstract

A method and system for preventing hung calls on a channel of a network interface device of a voice messaging system is described. A channel of the network interface device receives a new incoming call from the telephone network. If no other call is in progress on the same channel as the one on which the new call was received, the new incoming call is accepted. On the other hand, if another call is already in progress on this channel, the other call is terminated and the new incoming call is rejected. At this point, the network interface device is ready to accept any subsequent calls received on that channel.

Claims

1. A method for preventing hung calls on a channel of a network interface device (NID), the NID being interfaced from at least one host to a telephone network, the method comprising the acts of:

receiving on a channel of the network interface device a new incoming call from the telephone network;

assigning a substantially unique and host independent data structure (Call ID) to said new incoming call;

determining whether another call is already in progress on said channel; and

if no other call is in progress on said channel, accepting the new incoming call for processing on said channel;

if another call is already in progress on said channel, terminating the other call and rejecting the new incoming call, whereby said channel is made ready to accept any subsequent calls received on said channel.

2. A method as recited in claim 1, wherein the NID is part of a telephony-based voice messaging system.

3. A method as recited in claim 1, wherein the NID is a Network Interface Unit (NIU).

4. A method as recited in claim 1, wherein the NID is a Telephony Services Platform (TSP).

5. A method as recited in claim 4, wherein the method is used in a shared TSP environment.

6. A method as recited in claim 1, wherein the method is used in a voice messaging system of the type in which said at least one host computers is interfaced to the telephone network by the NID, and wherein a prescribed operation (Allow Group) involves a one of said at least one host computers providing a first data structure (Call ID) to the NID, wherein the first data structure further includes a first bit (Start) and a second bit (Stop), which the NID employs to determine whether to permit the new call to be processed on said channel or instead to terminate said other call and reject the new incoming call.

7. A method as recited in claim 6, wherein the first data structure (Call ID) comprises a first field (Host ID) that is host unique by uniquely identifying a one of said at least one host computers and wherein a second field provides said substantial uniqueness by providing a unique 32-bit integer that uniquely identifies a telephone call.

8. A method as recited in claim 6, wherein the first (Start) bit identifies a call that is new, and the second (Stop) bit identifies a call that is terminated.

9. A method as recited in claim 6, wherein, if a new call is sent to the NID on a given channel (Channel X) and there is no call in progress, than the call is accepted and the NID allows voice to be played using the given channel (Channel X).

10. A method as recited in claim 9, wherein, if a first Call ID (A) exists on the NID on the given channel and if the NID is provided an Allow Group with the same Call ID (A) and the first bit (Start) is set for the given channel, then the call in progress is maintained and the new call is rejected, whereas, if the NID is provided an Allow Group with a new Call ID (B) with the first bit (Start) set for the given channel, then the call in progress corresponding to the first Call ID (A) is cleared and the new call is rejected.

11. A computer readable storage medium comprising executable program code for carrying out the following method to prevent hung calls on a channel of a network interface device (NID) interfaced to a telephone network and to at least one host computer, the method comprising:

receiving on a channel of the network interface device a new incoming call from the telephone network;

assigning a substantially unique and host independent data structure (Call ID) to said new incoming call;

determining whether another call is already in progress on said channel; and

if no other call is in progress on said channel, accepting the new incoming call for processing on said channel;

if another call is already in progress on said channel, terminating the other call and rejecting the new incoming call, whereby said channel is made ready to accept any subsequent calls received on said channel.

12. A computer readable storage medium as recited in claim 11, wherein the host computer is interfaced to the telephone network by the NID, and wherein a prescribed operation (Allow Group) involves at least one of said at least one host computers providing a first data structure (Call ID) to the NID, wherein the first data structure includes a first bit (Start) and a second bit (Stop), and a unique across all hosts Call ID which the NID employs to determine whether to permit the new call to be processed on said channel or instead to terminate said other call and reject the new incoming call.

13. A computer readable storage medium as recited in claim 12, wherein the first data structure (Call ID) comprises a first field (Host ID) that uniquely identifies the host computer and a second field containing a unique 32-bit integer that uniquely identifies a telephone call.

14. A computer readable storage medium as recited in claim 12, wherein the first (Start) bit identifies a call that is new, and the second (Stop) bit identifies a call that is terminated.

15. A computer readable storage medium as recited in claim 12, wherein, if a new call is sent to the NID on a given channel and there is no call in progress, then the call is accepted and the NID allows voice to be played using the given channel.

16. A computer readable storage medium as recited in claim 15, wherein, if a first Call ID (A) exists on the NID on the given channel and if the NID is provided an Allow Group with the same Call ID (A) and the first bit (Start) is set for the given channel, then the call in progress is maintained and the new call is rejected, whereas, if the NID is provided an Allow Group with a new Call ID (B) with the first bit (Start) set for the given channel, then the call in progress corresponding to the first Call ID (A) is cleared and the new call is rejected.

17. A telephony-based voice messaging system, comprising:

a host computer; and

a network interface device (NID) operatively coupled to the host computer,

wherein the system is programmed to prevent hung calls on a channel of the NID when the NID is interfaced to a telephone network, the programmed process for preventing hung calls comprising the acts of;

receiving on a channel of the NID a new incoming call from the telephone network;

assigning a substantially unique and host independent data structure (Call ID) to said new incoming call;

determining whether another call is already in progress on said channel; and

if no other call is in progress on said channel, accepting the new incoming call for processing on said channel;

if another call is already in progress on said channel, terminating the other call and rejecting the new incoming call, whereby said channel is made ready to accept any subsequent calls received on said channel.

18. A system as recited in claim 17, wherein the NID is a Telephony Services Platform (TSP).

19. A system as recited in claim 18, further comprising a second NID interfaced to the host computer.

20. A system as recited in claim 17, wherein a prescribed operation (Allow Group) of the system involves the host computer providing the first data structure (Call ID) to the NID, wherein the first data structure includes a first bit (Start) and a second bit (Stop), which the NID employs to determine whether to permit the new call to be processed on said channel or instead to terminate said other call and reject the new incoming call.

21. A system as recited in claim 20, wherein the first data structure (Call ID) comprises a first field (Host ID) that uniquely identifies the host computer and a second field containing a unique 32-bit integer that uniquely identifies a telephone call.

22. A system as recited in claim 20, wherein the first (Start) bit identifies a call that is new, and the second (Stop) bit identifies a call that is terminated.

23. A system as recited in claim 20, wherein, if a new call is sent to the NID on a given channel (Channel X) and there is no call in progress, then the call is accepted and the NID allows voice to be played using the given channel (Channel X).

24. A system as recited in claim 23, wherein, if a first Call ID (A) exists on the NID on the given channel and if the NID is provided an Allow Group with the same Call ID (A) and the first bit (Start) is set for the given channel, then the call in progress is maintained and the new call is rejected, whereas, if the NID is provided an Allow Group with a new Call ID (B) with the first bit (Start) set for the given channel, then the call in progress corresponding to the first Call ID (A) is cleared and the new call is rejected.