TELEPHONY SYSTEM, CONNECTION CONTROL METHOD, CONNECTION CONTROL DEVICE AND RECORDING MEDIUM

• US 20080043989A1
• Filed: 08/15/2007
• Published: 02/21/2008
• Est. Priority Date: 08/17/2006
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: TANAKA, Masahiro, CHIGUSA, Kaori, NISHIDA, Minoru, FURUTONO, Tomoyuki, HIROSHIGE, Norimichi, KOGA, Akio, FUKUHARA, Ryuji, TAGANE, Junji, ODA, Ryuji
• Granted Patent: US 8,832,307 B2
• Time in Patent Office: Days
• US Class Current: 379/269
• CPC Class Codes: H04M 3/367 Traffic or load control
• CPC Class Codes: H04M 3/42195 Arrangements for calling back a calling subscriber when the wanted subscriber ceases to be busy H04M3/48
• CPC Class Codes: H04M 3/5238 with waiting time or load prediction arrangements

Abstract

When a connection control device determines that the connection control device is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value, the CPU of the connection control device forcefully disconnects an established call connection after a connection available time elapses, and, when an INVITE message is transmitted from a terminal device, the CPU of the connection control device receives the INVITE message, calculates the wait time, creates and transmits a response message stating the wait time, and stores the message as a reserved call on a reservation list.

Claims

1. A telephony system comprising:

a plurality of terminal devices; and

a connection control device capable of communicating with the terminal devices, wherein

one terminal device includes a transmitting section for transmitting a connection request for requesting establishment of a call connection with other terminal device to said connection control device,

said connection control device includes;

a storage section;

a receiving section for receiving the connection request;

a controller capable of;

establishing a call connection corresponding to the received connection request;

determining whether or not the connection control device is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

setting a connection available time until disconnecting an established call connection, when determined that the connection control device is in a congested state;

measuring a connection time of an established call connection;

disconnecting an established call connection when the connection time exceeds the connection available time;

if a connection request is received from one terminal device when determined that the connection control device is in a congested state, storing connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request in the storage section according to an order in which connection requests are received; and

calculating a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which connection requests are received; and

a transmitting section for transmitting time information indicating the wait time to other device.

2. The telephony system according to claim 1, wherein said controller of said connection control device is further capable of:

storing the time information indicating the wait time in the storage section for each stored connection information;

determining whether or not the wait time has elapsed; and

establishing a call connection between the corresponding terminal devices when determined that the wait time has elapsed.

3. The telephony system according to claim 1, comprising a plurality of said connection control devices, wherein

if a connection request is received from one terminal device when determined that one connection control device is in a congested state, the transmitting section of the one connection control device transmits to other connection control device the connection information and time information indicating the wait time corresponding to the received connection request,

said controller of other connection control device is further capable of:

storing the connection information and time information received from said one connection control device in the storage section;

determining, when a connection request from one terminal device is received, whether or not the terminal identification information about originating and destination terminal devices corresponding to the received connection request matches that in the stored connection information;

when determined that they match, determining whether or not the corresponding wait time has elapsed; and

discarding the received connection request if the wait time has not elapsed.

4. The telephony system according to claim 1, further comprising a storing device capable of communicating with said connection control device and storing connection information, wherein

said connection control device further transmits the stored connection information and time information corresponding to the connection information to said storing device, and

said storing device includes:

a receiving section for receiving connection information and time information corresponding to the connection information from said connection control device;

a storage section for storing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection information and the time information corresponding to the connection information as a connection list; and

a transmitting section for transmitting the connection list to said connection control device.

5. The telephony system according to claim 4, wherein

the receiving section of said connection control device receives the connection list from the storing device when it receives a connection request from one terminal device,

said controller of said connection control device is further capable of:

determining whether or not the terminal identification information about originating and destination terminal devices corresponding to the received connection request matches that in the connection information included in the received connection list;

when determined that they match, reading the corresponding time information from the received connection list;

determining whether or not the wait time shown by the read time information has elapsed; and

discarding the received connection request if the wait time has not elapsed.

6. The telephony system according to claim 1, wherein

said controller of said connection control device is further capable of:

measuring a post connection time since the establishment of a call connection between terminal devices corresponding to the stored connection information;

determining whether or not the post connection time has exceeded a predetermined time; and

deleting the stored connection information after a determination is made that the predetermined time has elapsed.

7. The telephony system according to claim 1, wherein

said controller of said connection control device is further capable of:

determining, when a connection request from one terminal device is received, whether or not the connection request contains priority call information representing a priority call given priority for connection;

when determined that the connection request contains priority call information, switching an order of the stored connection information to give priority to the received connection request; and

trying to establish a call connection corresponding to the received connection request irrespectively of whether or not said connection control device is in a congested state.

8. The telephony system according to claim 1, wherein

the transmitting section of said connection control device transmits disconnection information indicating the connection available time to a terminal device corresponding to the connection request for a call connection to be disconnected.

9. The telephony system according to claim 1, wherein

said controller of said connection control device is further capable of setting a time obtained by dividing the number of call connections capable of being simultaneously established by the number of call connections capable of being call-processed within a certain time as the connection available time when a determination is made that said connection control device is in a congested state.

10. The telephony system according to claim 1, wherein

said controller of said connection control device is further capable of calculating a time until expiration of a connection available time set for an established call connection, or a time until expiration of the connection available time for a call connection corresponding to connection information received earlier, as the wait time.

11. A telephony system comprising:

a plurality of terminal devices; and

a connection control device capable of communicating with the terminal devices, wherein

one terminal device includes means for transmitting a connection request for requesting establishment of a call connection with other terminal device to said connection control device, and

said connection control device includes;

means for receiving the connection request;

means for establishing a call connection corresponding to the received connection request;

congestion determining means for determining whether or not the connection control device is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

setting means for setting a connection available time until disconnecting an established call connection, when said congestion determining means determines that the connection control device is in a congested state;

means for measuring a connection time of an established call connection;

means for disconnecting an established call connection when the connection time exceeds the connection available time;

means for storing, if a connection request is received from one terminal device when the congestion determining means determines that the connection control device is in a congested state, connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request according to an order in which connection requests are received;

calculating means for calculating a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which connection requests are received; and

means for transmitting time information indicating the wait time to other device.

12. The telephony system according to claim 11, wherein said connection control device further includes:

means for storing the time information indicating the wait time for each stored connection information;

determining means for determining whether or not the wait time has elapsed; and

means for establishing a call connection between the corresponding terminal devices when said determining means determines that the wait time has elapsed.

13. The telephony system according to claim 11, comprising a plurality of said connection control devices, wherein

one connection control device includes means for transmitting, if a connection request is received from one terminal device when said congestion determining means determines that the connection control device is in a congested state, the connection information and time information indicating a wait time corresponding to the received connection request to other connection control device, and

other connection control device includes:

means for storing the connection information and time information received from said one connection control device;

means for determining, when a connection request from one terminal device is received, whether or not terminal identification information about the originating and destination terminal devices corresponding to the received connection request matches that in the stored connection information;

means for determining whether or not the corresponding wait time has elapsed, when determined that they match; and

means for discarding the received connection request if the wait time has not elapsed.

14. The telephony system according to claim 11, further comprising a storing device capable of communicating with said connection control device and storing connection information, wherein

said connection control device further transmits the stored connection information and time information corresponding to the connection information to said storing device, and

said storing device includes:

means for receiving connection information and time information corresponding to the connection information from said connection control device;

means for storing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection information and the time information corresponding to the connection information as a connection list; and

means for transmitting the connection list to said connection control device.

15. The telephony system according to claim 14, wherein

said connection control device includes:

means for receiving the connection list from the storing device when it receives a connection request from one terminal device;

means for determining whether or not the terminal identification information about the originating and destination terminal devices corresponding to the received connection request matches that in the connection information included in the received connection list;

means for reading the corresponding time information from the received connection list when determined that they match;

means for determining whether or not a wait time shown by the read time information has elapsed; and

means for discarding the received connection request if the wait time has not elapsed.

16. The telephony system according to claim 11, wherein

said connection control device includes:

means for measuring a post connection time since establishment of a call connection between terminal devices corresponding to the stored connection information;

progress determining means for determining whether or not the post connection time has exceeded a predetermined time; and

means for deleting the stored connection information after said progress determining means determines that the predetermined time has elapsed.

17. The telephony system according to claim 11, wherein

said connection control device includes:

means for determining, when a connection request from one terminal device is received, whether or not the connection request contains priority call information representing a priority call given priority for connection;

means for switching an order of the stored connection information to give priority to the received connection request when determined that the connection request contains priority call information; and

means for trying to establish a call connection corresponding to the received connection request irrespectively of whether or not said connection control device is in a congested state.

18. The telephony system according to claim 11, wherein

said connection control device includes means for transmitting disconnection information indicating the connection available time to a terminal device corresponding to the connection request for a call connection to be disconnected.

19. The telephony system according to claim 11, wherein

when said congestion determining means determines that said connection control device is in a congested state, said setting means sets a time obtained by dividing the number of call connections capable of being simultaneously established by the number of call connections capable of being call-processed within a certain time as the connection available time.

20. The telephony system according to claim 11, wherein

said calculating means calculates a time until expiration of a connection available time set for an established call connection by said setting means, or a time until expiration of the connection available time for a call connection corresponding to connection information received earlier, as the wait time.

21. A connection control method by receiving from one terminal device a connection request for requesting establishment of a call connection with other terminal device, and establishing a call connection corresponding to the received connection request, comprising the steps of:

determining whether or not it is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

setting a connection available time until disconnecting an established call connection, when determined that it is in a congested state;

measuring a connection time of an established call connection;

disconnecting an established call connection when the connection time exceeds the connection available time;

if a connection request is received from one terminal device when determined that it is in a congested state, storing connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request according to an order in which connection requests are received;

calculating a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which connection requests are received; and

transmitting information indicating the wait time to other device.

22. A connection control device comprising:

a storage section;

a receiving section for receiving from one terminal device a connection request for requesting establishment of a call connection with other terminal device;

a controller capable of;

establishing a call connection corresponding to the received connection request;

determining whether or not the connection control device is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

setting a connection available time until disconnecting an established call connection, when determined that the connection control device is in a congested state;

measuring a connection time of an established call connection;

disconnecting an established call connection when the connection time exceeds the connection available time;

if a connection request is received when determined that the connection control device is in a congested state, storing connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request in the storage section according to an order in which connection requests are received; and

calculating a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which connection requests are received; and

a transmitting section for transmitting time information indicating the wait time.

23. The connection control device according to claim 22, wherein said controller is further capable of:

storing the time information indicating the wait time in the storage section for each stored connection information;

determining whether or not the wait time has elapsed; and

establishing a call connection between the corresponding terminal devices when determined that the wait time has elapsed.

24. The connection control device according to claim 22, wherein said receiving section and said transmitting section transmit or receive the connection information and the time information to or from outside, and

said controller is further capable of:

storing the connection information and time information received from outside in said storage section;

when a connection request is received, determining whether or not terminal identification information about originating and destination terminal devices corresponding to the received connection request matches that in the stored connection information;

when determined that they match, determining whether or not the corresponding wait time has elapsed; and

discarding the received connection request if the wait time has not elapsed.

25. The connection control device according to claim 22, wherein said controller is further capable of:

measuring a post connection time since establishment of a call connection between terminal devices corresponding to the stored connection information;

determining whether the post connection time has exceeded a predetermined time; and

deleting the stored connection information after a determination is made that the predetermined time has elapsed.

26. The connection control device according to claim 22, wherein said controller is further capable of;

determining, when a connection request is received, whether or not the connection request contains priority call information representing a priority call given priority for connection;

when determined that the connection request contains priority call information, switching an order of the stored connection information to give priority to the received connection request; and

trying to establish a call connection corresponding to the received connection request irrespectively of whether or not said connection control device is in a congested state.

27. The connection control device according to claim 22, wherein the transmitting section transmits disconnection information indicating the connection available time.

28. A connection control device comprising:

means for receiving from one terminal device a connection request for requesting establishment of a call connection with other terminal device;

means for establishing a call connection corresponding to the received connection request;

congestion determining means for determining whether or not the connection control device is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

setting means for setting a connection available time until disconnecting an established call connection, when said congestion determining means determines that the connection control device is in a congested state;

means for measuring a connection time of an established call connection;

means for disconnecting an established call connection when the connection time exceeds the connection available time;

means for storing, if a connection request is received from one terminal device when the congestion determining means determines that the connection control device is in a congested state, connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request according to an order in which connection requests are received;

calculating means for calculating a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which the connection requests are received; and

means for transmitting time information indicating the wait time.

29. The connection control device according to claim 28, further comprising:

means for storing the time information indicating the wait time for each stored connection information;

determining means for determining whether or not the wait time has elapsed; and

means for establishing a call connection between the corresponding terminal devices when said determining means determines that the wait time has elapsed.

30. The connection control device according to claim 28, further comprising:

means for transmitting and receiving the connection information and the time information to or from outside;

means for storing the connection information and time information received from outside;

means for determining, when a connection request is received, whether or not the terminal identification information about originating and destination terminal devices corresponding to the received connection request matches that in the stored connection information;

means for determining whether or not the corresponding wait time has elapsed, when determined that they match; and

means for discarding the received connection request if the wait time has not elapsed.

31. The connection control device according to claim 28, further comprising:

means for measuring a post connection time since establishment of a call connection between terminal devices corresponding to the stored connection information;

progress determining means for determining whether or not the post connection time has exceeded a predetermined time; and

means for deleting the stored connection information after said progress determining means determines that the predetermined time has elapsed.

32. The connection control device according to claim 28, further comprising:

means for determining, when a connection request is received, whether or not the connection request contains priority call information representing a priority call given priority for connection;

means for switching an order of the stored connection information to give priority to the received connection request when determined that the connection request contains priority call information; and

means for trying to establish a call connection corresponding to the received connection request irrespectively of whether or not said connection control device is in a congested state.

33. The connection control device according to claim 28, further comprising means for transmitting disconnection information indicating the connection available time.

34. A recording medium storing a computer program for causing a computer capable of communicating with a plurality of terminal devices to receive from one terminal device a connection request for requesting establishment of a call connection with other terminal device and establish a call connection corresponding to the received connection request, said computer program comprising:

a step of causing the computer to determine whether or not it is in a congested state, based on whether a usage of at least one of hardware resources necessary for call processing to establish a call connection is equal to or more than a predetermined threshold value;

a step of causing the computer to set a connection available time until disconnecting an established call connection, when a determination is made that it is in a congested state;

a step of causing the computer to measure a connection time of an established call connection;

a step of causing the computer to disconnect the established call connection when the connection time exceeds the connection available time;

a step of causing the computer, if a connection request is received when determined that it is in a congested state, to store connection information containing terminal identification information identifying each of originating and destination terminal devices corresponding to the received connection request according to an order in which connection requests are received;

a step of causing the computer to calculate a wait time until establishment of a call connection between terminal devices corresponding to the stored connection information becomes available, based on the connection available time and the order in which connection requests are received; and

a step of causing the computer to transmit time information indicating the wait time.

35. The recording medium according to claim 34, wherein said computer program further comprises:

a step of causing the computer to store the time information indicating the wait time for each stored connection information;

a step of causing the computer to determine whether or not the wait time has elapsed; and

a step of causing the computer to establish a call connection between the corresponding terminal devices when determined that the wait time has elapsed.

36. The recording medium according to claim 34, wherein said computer program further comprises:

a step of causing the computer to transmit and receive the connection information and the time information to or from outside;

a step of causing the computer to store the connection information and time information received from outside;

a step of causing, when a connection request is received, the computer to determine whether or not the terminal identification information about originating and destination terminal devices corresponding to the received connection request matches that in the stored connection information;

a step of causing, when determined that they match, the computer to determine whether or not the corresponding wait time has elapsed; and

a step of causing the computer to discard the received connection request if the wait time has not elapsed.

37. The recording medium according to claim 34, wherein said computer program further comprises:

a step of causing the computer to measure a post connection time since establishment of a call connection between terminal devices corresponding to the stored connection information;

a step of causing the computer to determine whether or not the post connection time has exceeded a predetermined time; and

a step of causing the computer to delete the stored connection information after a determination is made that the predetermined time has elapsed.

38. The recording medium according to claim 34, wherein said computer program further comprises:

a step of causing, when a connection request is received, the computer to determine whether or not the connection request contains priority call information representing a priority call given priority for connection;

a step of causing, when determined that the connection request contains priority call information, the computer to switch an order of the stored connection information to give priority to the received connection request; and

a step of causing the computer to try to establish a call connection corresponding to the received connection request irrespectively of whether or not it is in a congested state.

39. The recording medium according to claim 34, wherein said computer program further comprises a step of causing the computer to transmit disconnection information indicating the connection available time.