Network telephone system

• US 20060133356A1
• Filed: 11/30/2005
• Published: 06/22/2006
• Est. Priority Date: 11/30/2004
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Suzukawa, Rumi
• Application Number:
  US11/289,310
• Publication Number:
  US 20060133356A1
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 65/1073 Registration or de-registration
• CPC Class Codes: H04L 65/1101 Session protocols
• CPC Class Codes: H04L 65/1104 Session initiation protocol [SIP]
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/147 Signalling methods or messages providing extensions to protocols defined by standardisation

Abstract

An SIP server continuously monitors the registration information of each of SIP terminals in a terminal registration state table. When the registration state of the SIP terminal is changed to “unregistered” as the Expires date is exceeded or a failure occurs in the SIP server, the SIP server transmits a REGISTER request message to the SIP terminal. When REGISTER comes from the SIP terminal in response to the REGISTER request message, the SIP server again sets the registration state of the SIP terminal in the terminal registration state table to “registered.”

Claims

1. A network telephone system comprising:

a plurality of telephone terminals connected to a communication network for transmitting a voice packet; and

a server for connecting the plurality of telephone terminals through the communication network and allowing the plurality of telephone terminals to communicate with each other,

wherein the server comprises;

a storage unit that stores in a recording medium a plurality of pieces of registration information indicating that communications are available to be conducted through the communication network in association with identification information indicating each of the plurality of telephone terminals connected to the communication network;

a detection unit that detects whether or not at least one of the plurality of pieces of registration information stored in the recording medium has been erased;

a request transmission unit that transmits, when the detection unit detects that at least one of the plurality of pieces of registration information is erased, a registration information acquisition request to the telephone terminal corresponding to the erased registration information; and

a processing unit that receives the registration information and the identification information sent from the requested telephone terminal in response to the registration information acquisition request and recording the registration information and the identification information in the recording medium, and

wherein each of the plurality of telephone terminals comprises an information transmission unit that transmits the registration information together with the identification information to the server in response to the acquisition request when the acquisition request is sent from the server.

2. The network telephone system according to claim 1, wherein the storage unit stores expiration date information that indicates expiration date of the registration information in association with the identification information in addition to the registration information,

wherein the detection unit detects that the registration information is erased from the recording medium according to the expiration date information, and

wherein when the registration information is erased from the recording medium, the request transmission unit transmits a registration information acquisition request to the corresponding telephone terminal.

3. The network telephone system according to claim 1, wherein when the acquisition request is sent from the server, the information transmission unit of the telephone terminal transmits a refusal signal for refusing registration to the server as required, and

wherein upon reception of the refusal signal sent from the requested telephone terminal, the processing unit of the server sets the corresponding telephone terminal to an unregistered state.

4. The network telephone system according to claim 1, wherein when the registration information and the identification information are unable to be received from the corresponding telephone terminal within a predetermined time period from the timing of sending the acquisition request, the processing unit sets the corresponding telephone terminal to an unregistered state.

5. The network telephone system according to claim 1, wherein the server further comprises:

an error transmission unit that sends a registration information acquisition request after sending an error message indicating that the communication network is unavailable to be used to the requesting telephone terminal when a request to use the communication network is sent from the telephone terminal being recorded in the recording medium as an unregistered state, and

wherein when the registration information and the identification information are sent from the requested telephone terminal in response to the registration information acquisition request, the processing unit records the registration information in the recording medium in association with the corresponding identification information.

6. A server for use in a network telephone system having a plurality of telephone terminals connected to a communication network to transmit a voice packet, and for connecting the plurality of telephone terminals through the communication network and allowing the plurality of telephone terminals to communicate with each other, the server comprising:

a storage unit that stores in a recording medium a plurality of pieces of registration information indicating that communications are available to be conducted through the communication network in association with identification information indicating each of the plurality of telephone terminals connected to the communication network;

a detection unit that detects whether or not at least one of the plurality of pieces of registration information stored in the recording medium has been erased;

a request transmission unit that transmits, when the detection unit detects that at least one of the plurality of pieces of registration information is erased, a registration information acquisition request to the telephone terminal corresponding to the erased registration information; and

a processing unit that receives the registration information and the identification information sent from the requested telephone terminal in response to the registration information acquisition request and recording the registration information and the identification information in the recording medium.

7. The server according to claim 6, wherein the storage unit stores expiration date information that indicates expiration date of the registration information in association with the identification information in addition to the registration information,

wherein the detection unit detects that the registration information is erased from the recording medium according to the expiration date information, and

wherein when the registration information is erased from the recording medium, the request transmission unit transmits a registration information acquisition request to the corresponding telephone terminal.

8. The server according to claim 6, wherein upon reception of a refusal signal sent from the requested telephone terminal, the processing unit of the server sets the corresponding telephone terminal to an unregistered state.

9. The server according to claim 6, wherein when the registration information and the identification information are unable to be received from the corresponding telephone terminal within a predetermined time period from the timing of sending the acquisition request, the processing unit sets the corresponding telephone terminal to an unregistered state.

10. The server according to claim 6, further comprising an error transmission unit that sends a registration information acquisition request after sending an error message indicating that the communication network is unavailable to be used to the requesting telephone terminal when a request to use the communication network is sent from the telephone terminal being recorded in the recording medium as an unregistered state,

wherein when the registration information and the identification information are sent from the requested telephone terminal in response to the registration information acquisition request, the processing unit records a registration information in the recording medium in association with the corresponding identification information.

11. A telephone terminal for use in a network telephone system having:

a plurality of the telephone terminals connected to a communication network; and

a server for connecting the plurality of telephone terminals through the communication network and allowing the plurality of telephone terminals to communicate with each other, the telephone terminal comprising;

a voice packet processing unit that converts a voice signal and a voice packet into one another for transmitting the voice packet through the communication network; and

an information transmission unit that transmits the registration information together with the identification information to the server in response to the acquisition request when the acquisition request is sent from the server.

12. The telephone terminal according to claim 11, wherein when an acquisition request is sent from the server, the information transmission unit of the telephone terminal transmits a refusal signal for refusing registration to the server as required.