JP2006014071A - Ip telephone network system, voip exchange, voip telephone control terminal, and alternative speech communication method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an IP telephone having high reliability and speech communication quality as a system matchable to a fixed telephone. <P>SOLUTION: A VoIP telephone exchange 10 determines the case where speech communication failure test information transmitted from a VoIP telephone control terminal 20 every prescribed time is not received as a speech communication failure, and when there is a connection request for speech communication with the VoIP telephone control terminal determined to have a failure, the VoIP exchange 10 transfers the speech communication to the VoIP telephone control terminal 20 through a public switched telephone network 50. The VoIP telephone control terminal 20 includes an IP communication packet priority transfer control part 26, attaches information instructing the priority transfer to an information packet relating to IP speech communication and transfers the packet more preferentially than a packet transmitted from a personal computer or the like. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an IP telephone network system, a VoIP exchange, a VoIP telephone control terminal, and a bypass communication method for realizing an IP (Internet Protocol) telephone using VoIP (Voice over Internet Protocol) technology.

  In recent years, with the spread of broadband IP networks, IP phones have begun to spread rapidly. IP telephones were initially called Internet telephones, and their call quality was not good due to the delay time of packetized transmission of voice data. Since then, Internet telephones that use a dedicated IP network separated from the public Internet network as the IP network of the part that becomes the communication path have been particularly called IP telephones. Since the dedicated IP network is usually configured using an optical fiber capable of high-speed communication of 100 Mbps or higher, the packetized transmission delay time and the like are greatly reduced. By using such a high-speed optical fiber network, the IP telephone call quality has been remarkably improved.

  On the other hand, IP telephones have just been put into practical use, and their use has been much less than conventional fixed telephones. Therefore, at present, IP telephones have not yet achieved high user trust. Actually, even if an IP telephone is connected to a dedicated IP network, various servers and personal computers are connected to the IP network, and various data are transmitted and received between them. Such data transmission / reception between the server and the personal computer acts as a negative factor on the call quality of the IP phone. In addition, in such an IP telephone network, there is still no actual data on what kind of failure occurs.

  Therefore, various techniques have been developed for improving the reliability and call quality of IP telephones.

  For example, Patent Document 1 discloses that when an IP phone is transmitted, the IP network serving as the IP phone call path is very congested, and when a predetermined call quality cannot be ensured, PBX (Private Branch eXchange) An example of call control for diverting a call to be transmitted to an IP network to a conventional public switched telephone network is shown. Further, Patent Document 2 shows an example of a method for detouring a call to the public switched telephone network or a gateway device without disconnecting the call when a failure occurs in the IP network during the call. Yes. That is, in Patent Document 1 and Patent Document 2, when a failure occurs in an IP telephone including an IP network, the failure is backed up by a fixed telephone using a conventional public switched telephone network.

  Non-Patent Document 1 and Non-Patent Document 2 describe a Diffserv (Differentiated Service) technique related to standardization of transmission control of IP packets transmitted and received in an IP network. According to the Diffserv technique, attributes such as reliability of the IP packet can be attached to the TOS (Type of Service) field of the header of the IP packet. According to this, priority transmission / reception control of IP packets can be performed by the value of the TOS field in the network switch at a lower level than the router. Therefore, for example, if a high priority value is assigned to the TOS field of the IP packet of the voice information related to the IP phone, the IP packet of the voice information is transmitted and received with priority. Therefore, even if the IP network is congested, the transmission delay of the IP packet of voice information is small, and the influence on the deterioration of the call quality can be suppressed.

JP-A-11-308345 (paragraphs 0012 to 0038, FIGS. 1 and 2) JP 2003-329027 A (paragraphs 0022 to 0098, FIGS. 1 to 16) K. Nichols, 3 others, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", Dec. 1998, [On line], [Search May 26, 2004], Internet <http : //www.ietf.org/rfc/rfc2474.txt> S. Blake, 5 others, "An Architecture for Differentiated Services", Dec. 1998, [On line], [Search May 26, 2004], Internet <http://www.ietf.org/rfc/ rfc2475.txt>

  Generally, the disadvantage that a user suffers when a failure occurs in an IP network is greater when a call is received than when a call is made. At the time of outgoing call, the user can know that there is no response from the exchange, etc., by simply performing the outgoing call operation, and can know at least that the outgoing call cannot be made. At that time, the user can immediately make a call using, for example, a conventional landline telephone. On the other hand, when a call cannot be received due to a failure in the IP network, the user cannot obtain any information because the user cannot obtain any information. For this reason, a situation may occur in which a call from an important customer is lost.

  However, in the example of Patent Document 1, a call that is a detour target is an outgoing call. Further, in the example of Patent Document 2, when an IP network failure occurs during a call, only the call is targeted for detouring. Therefore, none of the examples detects a failure of the IP network and bypasses the call when a call cannot be received due to a failure in the IP network. That is, in the prior art, no means or method for detecting an incoming call failure of a call that has a great disadvantage for the user and making an incoming call bypassing the failure has not yet been presented.

  In addition, regarding the technology for suppressing the deterioration of the call quality in the IP phone, only the concept of IP packet priority transmission control is shown in the Diffserv technology shown in Non-Patent Document 1 and Non-Patent Document 2, It was not shown how to achieve it.

  In view of the above-mentioned problems of the prior art, an object of the present invention is to provide an IP phone having high reliability and call quality as a system comparable to a fixed phone. A more specific problem of the present invention is that a failure of the IP network is detected when a call arrives, and if a failure is detected in the IP network at that time, the call is bypassed to the public switched telephone network. It is an object of the present invention to provide an IP telephone network system, a VoIP exchange, a VoIP telephone control terminal, a bypass call method, and a VoIP telephone control terminal that enables priority transmission control of voice information related to a call.

  In order to solve the above-mentioned problem, in the invention according to claim 1, an IP telephone network system includes an IP network, a VoIP telephone control terminal connected to the IP network and a key telephone, and controls the key telephone, and an IP It is configured to include a VoIP exchange that is connected to an IP telephone control terminal via a network and is connected to a public switched telephone network and performs a call exchange process. Then, the VoIP telephone control terminal transmits, to the VoIP exchange, call failure inspection information for detecting the presence or absence of a call failure on the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal to the VoIP exchange. The communication failure inspection information transmission means is provided. Further, the VoIP exchange detects a call failure in the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal based on the call failure inspection information transmitted from the VoIP telephone control terminal, and based on the detection result, the IP call Call failure detection means for setting a call failure flag indicating the presence or absence of a call failure on the line, a call failure flag set by the call failure detection means, and the IP call line when there is a call failure in the IP call line Failure information storage means for storing the telephone number of the public switching telephone network of the transfer destination for transferring the telephone call in association with the telephone number assigned to the IP telephone line, and a call exchange process for the VoIP exchange When requested, the telephone number assigned to the IP telephone line scheduled for connection in the exchange processing request with reference to the failure information storage means A corresponding call failure flag is read, and a call failure determination means for determining whether or not there is a call failure in the IP call line scheduled for connection based on the read call failure flag, and the IP call scheduled for connection by the call failure determination means When it is determined that the line has a call failure, the failure information storage means is referred to, and the telephone number of the public switched telephone network corresponding to the telephone number assigned to the IP call line scheduled to be connected in the exchange processing request is read. A call transfer means for transferring a call for which an exchange processing request has been made to a public switched telephone line having a telephone number of the read public switched telephone network is provided.

  By configuring the IP telephone network system as described above, the VoIP exchange monitors the call failure inspection information transmitted by the call failure inspection information transmission unit of the VoIP telephone control terminal at predetermined intervals by the call failure detection unit. When the predetermined call failure inspection information is not received within a predetermined time, it is possible to detect that there is a call failure on the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal. Further, the information on the IP communication line in which the call failure is detected is stored in the failure information storage means in association with the telephone number assigned to the IP call line as a call failure flag. Therefore, when there is a call exchange processing request, the VoIP exchange can know whether or not there is a call failure in the IP call line to be connected by referring to the failure information storage means. At that time, if there is a call failure in the IP call line scheduled to be connected, the VoIP exchange refers again to the failure information storage means, and the public number associated with the telephone number assigned to the IP call line. The telephone number of the exchange telephone network is read, and the call for which the exchange processing request is made is transferred to the public exchange telephone line having the read telephone number of the public exchange telephone network. As described above, it is possible to bypass the faulty IP telephone line.

  According to a second aspect of the present invention, in the IP telephone network system according to the first aspect, the VoIP telephone control terminal further includes a public switched telephone network connection means for connecting to the public switched telephone network. The failure information storage means in the VoIP exchange is used as the telephone number of the public switching telephone network of the transfer destination corresponding to the telephone number assigned to the IP telephone line connected to the VoIP telephone control terminal. The telephone number is assigned to the public switched telephone line connected to the public switched telephone network connection means.

  By configuring the IP telephone network system in this way, the connection destination of the public switched telephone network to which the call is transferred by the call transfer means when there is a call failure on the IP call line connected to the VoIP telephone control terminal is: It becomes the public switched telephone network connection means of the VoIP telephone control terminal itself. Therefore, an incoming call when there is a call failure on the IP call line is diverted to the public switched telephone network and arrives at the public switched telephone network connection means.

  The invention described in claim 3 claims the IP telephone network system of the invention described in claim 1 as an invention of a bypass call method, and has the same operational effects as in claim 1. The invention described in claim 4 and claim 5 claims that the VoIP switch constituting the IP telephone network system of the invention described in claim 1 is independent and is claimed as a VoIP switch invention. . The invention described in claim 6 claims that the VoIP telephone control terminal constituting the IP telephone network system of the invention described in claim 1 is independent and claimed as the invention of the VoIP telephone control terminal. .

  The VoIP telephone control terminal according to the sixth aspect of the invention further includes the VoIP exchange and the VoIP exchange based on response information from the VoIP exchange to information transmitted from the VoIP telephone control terminal. An outgoing call failure detection means for detecting a call failure in an IP call line connecting to an IP phone control terminal is provided. By configuring the VoIP telephone control terminal in this way, it is possible to detect when a call is made from the VoIP telephone control terminal.

  According to an eighth aspect of the present invention, the VoIP telephone control terminal according to the sixth or seventh aspect of the present invention further includes a public switched telephone network connection means for connecting a button telephone and a public switched telephone network. The configuration was as follows. By configuring the VoIP telephone control terminal in this way, when a call failure in the IP telephone line connected to the VoIP telephone control terminal is detected by the outgoing call failure detection means, the public switched telephone network connection means performs public switching telephone call A detour call via the network is possible.

  In the VoIP telephone control terminal according to the eighth aspect of the present invention, when a call failure is detected by the outgoing call failure detection means, the call originated from the key telephone is A detour connection is made to the public exchange telephone network via the public exchange telephone network connection means. By configuring the VoIP telephone control terminal in this way, even when there is a call failure on the IP telephone line connected to the VoIP telephone control terminal, the telephone call originated from the button telephone is connected to the public switched telephone network connection means. It is possible to make a call to the public switched telephone network via the Internet.

  Further, in the invention described in claim 10, the IP network is connected to the key telephone, the personal computer and the IP network, and is connected to the IP telephone control terminal via the IP network. In addition, in an IP telephone network system including a VoIP exchange that is connected to a public switched telephone network and performs call exchange processing, a VoIP telephone control terminal is located between a button telephone and an IP network, and a voice related to a telephone call. VoIP line control means for converting and controlling signal and control signal protocols; routing control means for controlling routing of information transferred between the personal computer and the IP network; and IP network and VoIP Line control means or Preferential transfer instruction information indicating that priority transfer control is to be performed is added to information input from the VoIP line control means between the routing control means and information input from the VoIP line control means is added from the routing control means. VoIP call information priority output means for giving priority to input information and outputting to the IP network is provided.

  In the invention of claim 10, since the VoIP telephone control terminal is configured to include the VoIP call information priority output means, the information inputted by the VoIP line control means, that is, the information of the voice signal and control signal of the IP telephone, The information input by the routing control means, that is, the information transmitted from the personal computer or the like can be prioritized and output to the IP network. For this reason, even if the IP network is congested due to information transmitted from a personal computer or the like, it is possible to suppress an increase in transmission delay related to the voice information of the IP phone, and to ensure a predetermined call quality.

  The invention described in claim 11 is the VoIP telephone control terminal according to claim 10, wherein the VoIP call information priority output means is connected to the VoIP line control means or the routing control means. It has a plurality of connection terminals set in advance, and information inputted from the connection terminals set to be connected to the VoIP line control means is inputted from the connection terminals set to be connected to the routing control means. The information is output to the IP network with priority over the information.

  Further, in the invention described in claim 12, in the VoIP telephone control terminal according to claim 10 or 11, the VoIP call information priority output means is connected to the VoIP line control means or connected to the routing control means. For a connection terminal that is set to be connected to the VoIP line control means, priority is given to adding priority transfer instruction information to information input from the connection terminal. The transfer instruction information adding means is provided.

  In the inventions according to the eleventh and twelfth aspects, the VoIP call information priority output means performs priority transfer control based on the type of the connection terminal to which the information is input, not the input information. Therefore, the VoIP call information priority output means can perform priority transfer control of information only based on the type of the input connection terminal without referring to or determining the content of the input information. Therefore, since the hardware scale (circuit scale) for realizing the VoIP call information priority output means and the priority transfer instruction information addition means can be reduced, the present invention can contribute to the reduction of the manufacturing cost of the VoIP telephone control terminal. it can.

  Further, in the invention described in claim 13, in the VoIP telephone control terminal according to any one of claims 10 to 12, the number of telephone lines simultaneously processed by the VoIP line control means is 32 lines or less. It was supposed to be. That is, by limiting the number of telephone lines simultaneously processed by the VoIP line control means to 32 lines or less, the IP network is prevented from being excessively congested (congested) for information transmission related to IP telephone calls. It is possible to suppress a decrease in call quality due to voice information transmission delay caused by congestion.

According to the first to sixth aspects of the present invention, the VoIP exchange can detect the presence / absence of a failure in the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal when attempting to receive a call to the connection destination. Therefore, the call can be diverted to the public switched telephone network and received by the VoIP telephone control terminal.
According to the seventh to ninth aspects of the present invention, the VoIP telephone control terminal can detect the presence or absence of a failure in the IP telephone line connecting the VoIP telephone control terminal and the VoIP exchange when attempting to make a call. Therefore, the call can be made to be diverted to the public switched telephone network.
Furthermore, according to the inventions of claims 10 to 13, congestion of the IP network can be avoided or voice information packets can be preferentially transferred, so that deterioration of the IP phone call quality is suppressed, and a predetermined call quality is set. Can be secured.

  As described above, according to the present invention, even if there is a failure in the IP network, it is possible to make a call that is bypassed to the public switched telephone network without any problem in both outgoing and incoming calls. Also, predetermined call quality can be ensured by priority transfer of voice information packets. Therefore, an IP phone having high reliability and call quality equivalent to that of a fixed phone can be realized.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a diagram showing an example of the configuration of an IP telephone network system in the first embodiment. In FIG. 1, the IP telephone network system in the first embodiment includes a VoIP exchange 10, a VoIP telephone control terminal 20, a key telephone 30, and an IP network 40. In addition, a public switched telephone network (PSTN) 50 exists on the outside, and the VoIP exchange 10 is connected to the public switched telephone network 50.

  In this embodiment, the IP network 40 is a network separated from the public Internet, and is a high-speed optical IP network using an optical fiber cable. The IP network 40 is usually connected to one VoIP exchange 10 and a number of VoIP telephone control terminals 20. Based on such a configuration, the VoIP telephone control terminal 20 and the VoIP exchange 10 will be described in more detail below.

<VoIP telephone control terminal 20>
The VoIP telephone control terminal 20 includes a VoIP line control unit 21, a button telephone control unit 22, a call failure inspection information transmission unit 23, an outgoing call failure detection unit 24, a PSTN connection unit 25, and other blocks (not shown). As a PBX function and a protocol conversion processing function. Here, the call failure inspection information transmission unit 23 is a call failure inspection information transmission unit in the claims, and similarly, the outgoing call failure detection unit 24 is an outgoing call failure detection unit, and the PSTN connection unit 25 is The public switched telephone network connection means.

  The button telephone control unit 22 is a block that executes the PBX function. The key telephone control unit 22 is provided with, for example, a housing unit for 60 extension telephone lines and, for example, 6 external telephone lines. A key telephone 30 is connected to the extension telephone line side, and the external telephone line side is connected to the key telephone control unit 22. Is connected to a signal line corresponding to an external telephone line output from the VoIP line control unit 21. The button telephone control unit 22 performs line exchange processing between the extension telephone lines or between the extension telephone line and the external telephone line.

  On the other hand, the VoIP line control unit 21 is a block that performs protocol conversion processing. The VoIP line control unit 21 is connected to a signal line corresponding to an external telephone line output from the button telephone control unit 22 and via a media converter (device for converting an optical signal and an electric signal) (not shown). Connected to the optical fiber cable of the IP network 40. At this time, the specification of the signal corresponding to the external telephone line connecting the key telephone control unit 22 and the VoIP line control unit 21 is based on the conventional analog signal, while the transmission of information in the IP network 40 is H . 323, SIP (Session Initiation Protocol), and other IP protocols.

  Therefore, the VoIP line control unit 21 performs signal and protocol conversion between a signal corresponding to the external telephone line connected to the button telephone control unit 22 and a signal line connected to the IP network 40. That is, the VoIP line control unit 21 receives an analog dial signal or voice signal emitted from the key telephone 30 via the key telephone control unit 22, converts it into a digital signal, and packetizes it based on a predetermined protocol. . Then, the packetized dial signal data and voice signal data are transmitted to the IP network 40. The VoIP line control unit 21 returns the packetized dial signal data and voice signal data input from the IP network 40 according to a predetermined protocol to the original analog signal, and uses the button telephone control unit as a line signal. 22 is supplied.

  The VoIP line control unit 21 can simultaneously control, for example, calls on six external telephone lines. The signals of the six external telephone lines are time multiplexed (TDM) and connected to the IP network 40 by a single optical fiber cable. Therefore, the VoIP line control unit 21 also performs time multiplexing processing.

  In the VoIP telephone control terminal 20, the call failure inspection information transmission unit 23, the outgoing call failure detection unit 24, and the PSTN connection unit 25 execute a function of detecting a failure in the IP telephone line and forming a bypass communication path at the time of failure. The details will be described later. The IP telephone line is a telephone line that connects the VoIP exchange 10 and the user's IP telephone. However, in this embodiment, since the VoIP telephone control terminal 20 has a PBX function, the IP telephone line is a line connecting the VoIP switch 10 to the VoIP telephone control terminal 20.

<VoIP switch 10>
In FIG. 1, a VoIP exchange 10 includes a VoIP line switching unit 12, an IP network interface unit 13, a PSTN interface unit 11, a call failure detection unit 14, a call failure determination unit 15, a call transfer unit 16, a failure information storage unit 17, and an illustration. Not composed of other blocks. Here, the call failure detection unit 14 is a call failure detection unit in the claims. Similarly, the call failure determination unit 15 is a call failure determination unit, the call transfer unit 16 is a call transfer unit, and a failure information storage. The unit 17 is a failure information storage unit.

  The VoIP exchange 10 is connected to the IP network 40 and the public switched telephone network 50, and performs a call exchange process between IP telephone lines assigned to each VoIP telephone control terminal 20 connected to the IP network 40, and is connected to the IP network 40. Call exchange processing is performed between an IP telephone line assigned to each connected VoIP telephone control terminal 20 and a conventional fixed telephone line connected to the public switched telephone network 50.

  In the VoIP exchange 10, the IP network interface unit 13 receives dial signal data and voice signal data packetized in accordance with a predetermined protocol with the VoIP telephone control terminal 20, and sends it to the VoIP line exchange unit 12. Request a call exchange. When receiving a call exchange request, the VoIP circuit exchange unit 12 obtains the IP address of the other party of the call or a telephone number in the public switched telephone network 50 based on the information of the dial signal. Then, the IP network interface unit 13 or the PSTN interface unit 11 is instructed to add the IP address or dial signal data of the call partner and connect the call to the call partner.

  Upon receiving the call connection instruction, the IP network interface unit 13 establishes a call path to the call destination in the IP network 40 according to a predetermined protocol based on the attached IP address of the call destination, Control transmission and reception. Similarly, when receiving a call connection instruction, the PSTN interface unit 11 sends dial signal information to a relay exchange (not shown) in the public switched telephone network 50 and requests a call exchange process. When a response for establishing a route in the public exchange telephone network 50 is received from the relay exchange, the call data is transmitted / received to / from the relay exchange.

  In the VoIP exchange 10, the call failure detection unit 14, the call failure determination unit 15, the call transfer unit 16, and the failure information storage unit 17 have a function of detecting a failure in the IP telephone line and forming a bypass communication path at the time of the failure. The details will be described later.

<How to bypass call failure when receiving a call>
Next, a method for bypassing a call failure at the time of incoming call will be described with reference to FIGS. 2 to 4 in addition to FIG. Here, FIG. 2 is a diagram showing a procedure for detecting a call failure in advance in order to bypass the call when a call is received. FIG. 3 is a diagram illustrating a configuration of a failure storage information storage unit that stores a result of detecting a call failure in advance in order to bypass the call when a call is received. FIG. 4 is a diagram showing a procedure for bypassing the call failure based on the result of detecting the call failure in advance.

  In FIG. 2, as an initial process, the VoIP exchange 10 first stores in the failure information storage unit 17 the telephone number of the transfer destination public switched telephone network 50 to which a call is to be transferred when using an IP telephone line (step S10). That is, as shown in FIG. 3, the telephone number of the public switched telephone network 50 is stored in correspondence with each telephone number of the IP telephone line. In this case, when a plurality of IP telephone lines are connected to the VoIP telephone control terminal 20, the same telephone number of the public switched telephone network 50 may be associated with all of them.

  The telephone number of the public switched telephone network 50 stored in the failure information storage unit 17 is input by the user from the key telephone 30 to the VoIP telephone control terminal 20 in a predetermined sequence, for example, and the VoIP telephone control terminal 20 inputs the telephone number. The received telephone number may be sent to the VoIP exchange 10 according to a predetermined protocol.

  When the process of step S10 is completed, the VoIP exchange 10 starts detecting a call failure on the IP telephone line from the VoIP exchange 10 to the VoIP telephone control terminal 20. In order to detect the call failure, the VoIP exchange 10 receives call failure inspection information from the VoIP telephone control terminal 20 every predetermined time. If the VoIP exchange 10 does not receive the call failure inspection information within a predetermined time, the VoIP exchange 10 or the VoIP telephone control terminal 20 itself has a problem with the IP telephone line between the VoIP exchange 10 and the VoIP telephone control terminal 20. Judge that there was.

  Note that the call failure inspection information transmitted by the VoIP telephone control terminal 20 may be any information as long as it is information indicating that the VoIP telephone control terminal 20 has transmitted for the call failure inspection. The call failure inspection information includes expiration date information indicating a time limit during which the call failure inspection information is valid. Therefore, in this case, the VoIP exchange 10 receives the call failure inspection information including the expiration date information, and receives the call failure inspection information including the next new expiration date information within the expiration date. If not, it is determined that there is a failure in the IP telephone line.

  Steps S20 and S21 show a procedure in which the VoIP telephone control terminal 20 transmits call failure inspection information every predetermined time. In the VoIP telephone control terminal 20, the call failure inspection information transmission unit 23 generates expiration date information and embeds the expiration date information in the call failure inspection information. Then, call failure inspection information is transmitted to the VoIP exchange 10 (step 20). After that, it waits for a predetermined time that does not exceed the expiration date (No in step S21), and when the predetermined time elapses (Yes in step S21), step S20 and step S21 are repeated again. .

  On the other hand, the procedure from step S11 to step S15 shows a procedure for the VoIP exchange 10 to detect a call failure. First, the call failure detection unit 14 of the VoIP exchange 10 determines whether or not the expiration date included in the call failure inspection information sent before has passed (step S11). As a result of the determination, if the expiration date has not yet elapsed (No in step S11), it is determined whether new call failure inspection information for extending the expiration date has been received (step S12). . As a result of the determination, if new call failure inspection information has been received (Yes in step S12), the call failure flag is reset (step S13), and the call failure flag is stored in the failure information storage unit 17. (Step S15). And it returns to step S11 and performs the process after step S11 repeatedly. Further, as a result of the determination in step S12, if new call failure inspection information has not been received (No in step S12), the process returns to step S11 as it is, and the processes in and after step S11 are repeatedly executed.

On the other hand, if the expiration date has already passed in the determination of the expiration date in step S11 (Yes in step S11), a call failure flag is set (step S14), and the call failure flag is set to the failure information storage unit 17. (Step S15). And it returns to step S11 and performs the process after step S11 repeatedly.
In step 15, the failure information storage unit 17 stores “0” when the call failure flag is reset, and “1” when the call failure flag is set. Remember.

  The above procedure is executed for all the IP telephone lines connecting the VoIP exchange 10 and each VoIP telephone control terminal 20. As a result, it is determined whether or not there is a call failure for all the IP telephone lines connecting the VoIP switch 10 and each VoIP telephone control terminal 20 every predetermined time, and the result is the telephone number of the IP telephone line. It is stored in the failure information storage unit 17 as the corresponding call failure flag.

  Next, referring to FIG. 1 and FIG. 4, a procedure for detouring a call when there is a call failure on the IP call line to which the VoIP exchange 10 tried to connect the call will be described.

  When the VoIP circuit switching unit 12 receives a call exchange processing request via the IP network interface unit 13 or the PSTN interface unit 11, the VoIP circuit switching unit 12 is scheduled to connect with the exchange processing request based on the information of the dial signal attached to the exchange processing request. The telephone number of the IP telephone line is extracted (step S30). Then, the call failure determination unit 15 refers to the failure information storage unit 17 based on the extracted telephone number of the IP call line scheduled to be connected, and sets a call failure flag associated with the phone number of the IP call line. Read (step S31). Further, the call failure determination unit 15 determines the presence or absence of a call failure based on the value of the read call failure flag (step S32).

  As a result of the determination in step S32, when it is determined that there is a call failure (Yes in step S32), the call failure determination unit 15 refers to the failure information storage unit 17 again, and the IP call of the exchange process target The telephone number of the public switched telephone network associated with the telephone number of the line is read (step S33). Then, the call transfer unit 16 transfers the call to be exchanged to the public exchange telephone line of the telephone number of the public exchange telephone network read by the call failure determination unit 15 (step S34). On the other hand, if the result of determination in step S32 is that there is no call failure (No in step S32), normal exchange processing is performed (step S35). That is, the call is connected to the IP call line that is initially scheduled for connection.

  As described above, by executing the procedure shown in FIG. 2 and FIG. 4, the VoIP exchange 10 can detect whether or not there is a call failure in the IP call line to which the call to be exchanged is connected. If there is a failure, the call can be transferred to the public switched telephone line of the public switched telephone network 50.

  Here, the public exchange telephone line as the transfer destination is connected to the PSTN connection unit 25 provided in the VoIP telephone control terminal 20 connected to the IP telephone line in which the telephone call has been failed. In order to realize this, in the failure information storage unit 17 of FIG. 3, the public switched telephone line connected to the PSTN connecting unit 25 is used as the telephone number of the destination public switched telephone network corresponding to the telephone number of the IP telephone line. May be stored in the phone number. Further, an independent fixed telephone (not shown) may be connected to the PSTN connection unit 25. Alternatively, the PSTN connection unit 25 is connected to a signal corresponding to the outside line of the key telephone control unit 22. In this way, even if there is a failure in the IP telephone line connected to his / her VoIP telephone control terminal 20, the user can make a call to be received on the IP telephone line by using the public switched telephone network 50. Since the incoming call is received by the public switched telephone line connected to the PSTN connection unit 25, it is possible to make a call using an independent fixed telephone or the key telephone 30.

<Call bypassing method when making a call>
FIG. 5 is a diagram showing a procedure for bypassing a call failure when a call failure occurs when a call is made from the key telephone 30. In this case, when a call is made, whether or not there is a call failure on the IP call line is determined based on whether or not there is a response from the VoIP exchange 10.

  First, the VoIP telephone control terminal 20 (see FIG. 1) transmits connection request information such as a dial signal transmitted from the key telephone 30 to the VoIP exchange 10 according to a predetermined protocol (step S51). Then, the outgoing call failure detection unit 24 determines whether or not there is a response to the transmission (step S52). As a result, when any response is received from the VoIP exchange 10 (Yes in step S52), a request for connection of a normal IP telephone line is requested to the VoIP exchange 10 (step S57).

  On the other hand, when there is no response from the VoIP exchange 10 in step S52 (No in step S52), an output line corresponding to the outside line of the key telephone control unit 22 is connected to the PSTN connection unit 25 (step S53). At this time, it is assumed that at least one public switched telephone line from the public switched telephone network 50 is connected to the PSTN connection unit 25. Then, the key telephone control unit 22 transmits a connection request again with the same telephone number (step S54). Then, in this case, since the call line is forcibly connected to the PSTN connection unit 25, the outgoing connection request is sent to the public switched telephone network 50 side. Accordingly, when the connection request is accepted, a call is made via the public switched telephone network 50 (step S55). When the call is completed, the output line corresponding to the outside line of the key telephone control unit 22 is restored and connected to the VoIP line control unit 21 (step S56).

  According to the above procedure, when a call is made from the key telephone 30, the VoIP telephone control terminal 20 can detect a call failure on the IP call line to be sent, and when a call failure is detected. Can bypass the outgoing call to the public switched telephone network 50 without placing an extra burden on the user.

<< Second Embodiment >>
Next, a second embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 6 is a diagram showing an example of the configuration of the IP telephone network system in the second embodiment. In FIG. 6, the IP telephone network system in the second embodiment includes a VoIP exchange 10, a VoIP telephone control terminal 20a, a key telephone 30, a personal computer 60, and an IP network 40. A public switched telephone network 50 exists outside the VoIP switch 10 and is connected to the public switched telephone network 50.

  In this embodiment, as in the case of the first embodiment, the IP network 40 is a network separated from the public Internet, and is a high-speed optical IP network using an optical fiber cable. Suppose there is. In FIG. 6 and subsequent drawings including FIG. 6, components denoted by the same reference numerals as those in FIG. 1 indicate the same components, and description of the components is omitted.

  In FIG. 6, the personal computer 60 does not necessarily have to be a personal computer, and may be a server that manages various systems or a terminal device of the server. Any information device may be connected.

<VoIP telephone control terminal 20a>
In FIG. 6, the VoIP telephone control terminal 20a includes a VoIP line control unit 21a, a button telephone control unit 22, a VoIP call packet priority transfer control unit 26, a router 27, and other blocks not shown. That is, the VoIP telephone control terminal 20a in the present embodiment has a configuration in which the VoIP telephone call packet priority transfer control unit 26 and the router 27 are added to the VoIP telephone control terminal 20 (see FIG. 1) in the first embodiment. . The VoIP call packet priority transfer control unit 26 corresponds to the VoIP call information priority output means in the claims, and the router 27 corresponds to the routing control means in the claims.

  In the present embodiment, the VoIP telephone control terminal 20a includes a call failure inspection information transmission unit 23, an outgoing call failure detection unit 24, and the VoIP telephone control terminal 20 included in the first embodiment (see FIG. 1). Although the PSTN connection unit 25 is not included, a configuration including them may be used.

  In FIG. 6, the router 27 is normally connected to a plurality of personal computers 60 and the IP network 40, and performs information transfer control and routing control related to the information transfer in the plurality of personal computers 60 and the IP network 40. In the present embodiment, the router 27 is not directly connected to the IP network 40 but is connected via the VoIP call packet priority transfer control unit 26. The VoIP call packet priority transfer control unit 26 is connected to the IP network 40, the VoIP line control unit 21a, and the router 27, and controls the transfer of IP packets between the IP network 40 and the VoIP line control unit 21a or the router 27. Do. In the transfer control, the VoIP call packet priority transfer control unit 26 transfers the IP packet transmitted from the VoIP line control unit 21 a to the IP network 40 with priority over the packet transmitted from the router 27.

<VoIP call packet priority transfer control unit 26>
Next, the configuration and function of the VoIP call packet priority transfer control unit 26 will be described in more detail with reference to FIG. FIG. 7 is a diagram showing the configuration of the VoIP call packet priority transfer control unit in the VoIP telephone control terminal. In FIG. 7, a VoIP call packet priority transfer control unit 26 includes a VoIP call packet priority output unit 261, an output packet queue 262, a priority transfer instruction information addition unit 263, a VoIP call line connection port 264, and an Internet line connection port. H.265.

  The priority transfer instruction information adding unit 263 corresponds to priority transfer instruction information adding means in the claims. Further, in FIG. 7, for the convenience of explanation, blocks that are not related to the priority transfer control of the VoIP call packet, that is, IP packet input control from the IP network 40 side to the VoIP line control unit 21a and the router 27 side are controlled. The description of such blocks is omitted.

  In FIG. 7, a VoIP call line connection port 264 is a terminal for receiving a signal output from the VoIP line control unit 21a, through which voice information related to IP telephone calls and IP packets for control information are transferred. The The Internet line connection port 265 is connected to an output signal from the router 27, and IP packets of various information handled by the personal computer 60 are transferred through this terminal.

  Next, the priority transfer instruction information adding unit 263 adds the priority transfer instruction information with the highest priority to the IP packet transferred from the VoIP line control unit 21a via the VoIP call line connection port 264. Here, the priority transfer instruction information is set in a TOS (Type of Service) field of the header portion of the IP packet, as will be described next.

  FIG. 8 is a diagram showing the head part of the header part of IPv4 (Internet Protocol Version 4). In the head part 81 of the IPv4 header part, an 8-bit TOS field 82 is secured following 4-bit version information (version) and 4-bit header length information (header length). The TOS field 82 originally contains information representing the attributes of the IP packet, and the first 3 bits b1, b2, and b3 are called “precedence” and represent information representing the importance or priority of the IP packet. Arrangements were made for accommodation. Conventionally, however, the TOS field is rarely used because it is assumed that the definition and usage of the TOS field are ambiguous or only used in a closed system.

Therefore, in this embodiment, the first 3 bits b1, b2, and b3 (that is, precedence) of the TOS field 82 are used as the priority transfer instruction information 83. The priority transfer instruction information 83 is assumed to be 3-bit information indicating priority, that is, a numerical value from 0 to 7. In this case, the larger the numerical value, the higher the priority, and the numerical value 7 (binary “111”) is the highest priority.
These agreements are common agreements used in the entire IP telephone network system of this embodiment.

Next, returning to FIG. 7, the description of the VoIP call packet priority transfer control unit 26 will be continued.
The priority transfer instruction information adding unit 263, in accordance with the definition of the priority transfer instruction information 83 shown in FIG. 8, is the top 3 of the TOS field of the IP packet transferred from the VoIP line control unit 21a via the VoIP call line connection port 264. A binary number “111” is set in the bits b1, b2, and b3.

  On the other hand, since the priority transfer instruction information adding unit 263 is not provided on the Internet line connection port 265 side, an IP packet transferred from the personal computer 60 via the Internet line connection port 265 contains information on the TOS field. No setting operation is performed. Therefore, in this case, the value initially set in the personal computer 60 is stored as it is as the value of the TOS field.

  As described above, the binary number “111” is set as the priority transfer instruction information 83 in the IP packet transferred from the VoIP line control unit 21a via the VoIP call line connection port 264, and the PC 60 sends the Internet line. In the IP packet transferred via the connection port 265, the priority transfer instruction information 83 becomes the value set in the personal computer 60 as it is.

  Next, the IP packet transferred from the VoIP line control unit 21a via the VoIP call line connection port 264 and the IP packet transferred from the personal computer 60 via the Internet line connection port 265 are output packets. Stored in the queue 262. Here, each of the output packet queues 262 is usually configured by a FIFO (First in First Out) type memory.

  When an IP packet to be output is stored in any of the output packet queues 262, the VoIP call packet priority output unit 261 immediately reads it and outputs it to the IP network 40. However, if IP packets are simultaneously stored in a plurality of output packet queues 262 or reading from the output packet queue 262 is delayed due to processing delays in protocol communication, the IP packets to be output stay in the plurality of output packet queues 262. Will do. In this case, the VoIP call packet priority output unit 261 reads out the staying IP packet in accordance with a predetermined priority assigned to each output packet queue 262 and outputs it to the IP network 40.

  In this embodiment, the read priority of the output packet queue 262 connected to the VoIP call line connection port 264 is set higher than the read priority of the output packet queue 262 connected to the Internet line connection port 265. In this case, the priority order is not set based on the priority transfer instruction information 83 attached to the IP packet, but the input side connection port to which the output packet queue 262 is connected is the VoIP telephone line connection port 264. The Internet connection port 265 is set. By doing so, it is not necessary to read the priority transfer instruction information 83 attached to the IP packet and determine the priority thereof, and accordingly, the configuration of the VoIP call packet priority output unit 261 is simplified.

  As described above, the VoIP call packet priority output unit 261 stays in the output packet queue 262 connected to the Internet line connection port 265, while staying in the output packet queue 262 connected to the VoIP call line connection port 264. The data is read out with priority over the IP packet and output to the IP network 40. That is, the VoIP call packet priority transfer control unit 26 sets the priority transfer instruction information 83 to the highest priority for the IP packet input via the VoIP call line connection port 264 by the priority transfer instruction information 83, and at the same time, the VoIP call The packet priority output unit 261 performs control to preferentially output IP packets input via the VoIP call line connection port 264 over IP packets input via the Internet line connection port 265.

  In FIG. 7 illustrating the present embodiment, the VoIP call packet priority transfer control unit 26 includes only one Internet line connection port 265, but includes a plurality of Internet line connection ports 265. It doesn't matter.

  Further, when IP packets to be output are accumulated in a plurality of output packet queues 262 set with the same level of priority, for example, from the output packet queue 262 selected by a known FIFO method or round robin method. What is necessary is just to read an IP packet.

  In the present embodiment, the personal computer 60 does not assume that priority is given to the priority transfer instruction information 83 in the TOS field of the IP packet, but 0 to 7 depending on the type of information transmitted by the personal computer 60. Priorities up to may be attached. However, even if the priority is 7, the VoIP call packet priority output unit 261 does not perform priority control based on the information, and therefore, the VoIP call packet priority output unit 261 outputs priority in particular. Never happen.

  As described above, in the present embodiment, the IP packet related to the IP telephone call transferred from the VoIP line control unit 21 a is transferred in preference to the IP packets of various information transferred from the personal computer 60. Therefore, even when the amount of IP packets transferred from the personal computer 60 increases, the transmission of IP packets related to the IP telephone call is not delayed, and the call quality deteriorates due to the transmission delay of the IP packet. Can be prevented.

  In the present embodiment, another measure is taken to prevent a decrease in call quality. The countermeasure is to limit the number of IP telephone lines that can be simultaneously processed by the VoIP line controller 21a to 32 in FIG. That is, in one VoIP line control unit 21a, the number of generation sources that simultaneously generate IP packets related to a call is suppressed to 32 or less.

  FIG. 9 is a diagram for explaining the reason why the maximum value of the number of IP telephone lines that can be simultaneously processed by the VoIP line control unit is set to 32. FIG. 9 is a diagram showing the configuration of the same IP telephone network system as FIG. 6, but FIG. 9 shows an access point node 45 which is not shown in FIG. The access point node 45 is connected to a plurality of VoIP telephone control terminals 20a by an optical fiber cable called an access line, and is connected to the IP network 40 by a similar optical fiber cable.

  In the present embodiment, the access point node 45 is connected to 100 VoIP telephone control terminals 20a as design values. That is, the access point node 45 is connected to the IP network 40 by combining 100 access line optical fiber cables into one optical fiber. Therefore, here, assuming that the number of access lines connected to one access point node 45 is N, 1 / N is referred to as a line concentration rate. Therefore, in the present embodiment, the line concentration rate is 1/100.

  Here, the access line bandwidth of the access line in this embodiment is 100 Mbps, and the used bandwidth used by one IP telephone line is 85 kbps. Therefore, the line capacity of one optical fiber cable is 1176 (= 100 Mbps / 85 kbps) line. On the other hand, since the line bandwidth of the optical fiber cable in which the access point node 45 is connected to the IP network 40 is 100 Mbps, which is the same as that of the access line, when the line concentration rate is 1/100, one VoIP telephone control terminal 20a The line capacity allocated to the access line is 11.76 lines.

  By the way, 100% of the call line is not occupied by the call. In general, the rate at which a call line is occupied by a call (call) is called a call concentration rate. It is known that when this call concentration rate exceeds 37%, new calls cannot be made to the line, that is, troubles such as difficulty in making a call increase. In other words, this means that the line can be used until the call concentration rate reaches 37%.

  Therefore, when the line capacity allocated to the access line of one VoIP telephone control terminal 20a is 11.76 lines and the call concentration rate is 37%, the line capacity of the access line is substantially 31. .8 lines (= 11.76 / 0.37). Therefore, the maximum number of IP telephone lines that can be processed simultaneously by one VoIP telephone control terminal 20a can be set to 32.

  Therefore, if the maximum number of IP call lines that can be processed simultaneously by one VoIP telephone control terminal 20a is 32, even if all 100 VoIP telephone control terminals 20a process 32 line calls simultaneously, access In the fiber cable connecting the point node 45 and the IP network 40, the IP packet related to the call does not overflow. Therefore, transmission delay of the IP packet related to the call does not newly occur, and a predetermined call quality can be ensured.

  In addition, the numerical value demonstrated in the above embodiment can be generalized with a symbol as follows. That is, M is the maximum number of IP call lines that can be processed simultaneously in the VoIP telephone control terminal 20a, C is the call capacity of the communication line connecting the access point node 45 and the IP network 40, and the line concentration rate in the access point node 45 is If p and the call concentration rate are s, M is given by the equation M = C × p / s.

It is the figure which showed the example of the structure of the IP telephone network system in the 1st Embodiment of this invention. In the 1st Embodiment of this invention, it is the figure which showed the procedure which detects a telephone failure beforehand in order to detour a telephone call at the time of the incoming call. FIG. 3 is a diagram illustrating a configuration of a failure storage information storage unit that stores a result of detecting a call failure in advance in order to bypass a call when a call is received in the first embodiment of the present invention. In the 1st Embodiment of this invention, it is the figure which showed the procedure which bypasses a telephone call failure based on the result of having detected a telephone call failure beforehand. In the 1st Embodiment of this invention, it is the figure which showed the procedure which detours a telephone call failure, when there is a telephone call failure when calling from a button telephone. It is the figure which showed the example of the structure of the IP telephone network system in the 2nd Embodiment of this invention. It is the figure which showed the structure of the VoIP telephone call packet priority transfer control part of the VoIP telephone control terminal in the 2nd Embodiment of this invention. It is the figure which showed the head part of the header part of IPv4. In the 2nd Embodiment of this invention, it is a figure for demonstrating the reason which made the maximum value of the number of IP telephone communication lines which a VoIP line control part can process simultaneously into 32. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 VoIP exchange 11 PSTN interface part 12 VoIP line switching part 13 IP network interface part 14 Call failure detection part 15 Call failure determination part 16 Call transfer part 17 Failure information storage part 20, 20a VoIP telephone control terminal 21, 21a VoIP line control part 22 Button Telephone Control Unit 23 Call Failure Inspection Information Transmitting Unit 24 Outgoing Call Failure Detection Unit 25 PSTN Connection Unit 30 Button Telephone 40 IP Network 45 Access Point Node 50 Public Switched Telephone Network 60 Personal Computer 82 TOS Field 83 Priority Transfer Instruction Information 261 VoIP Call Packet priority output unit 262 Output packet queue 263 Priority transfer instruction information addition unit 264 VoIP call line connection port 265 Internet line connection port

Claims (13)

An IP network, connected to the IP network and a key telephone, and connected to the IP telephone control terminal via the IP network and connected to the public switched telephone network. In an IP telephone network system equipped with a VoIP exchange that performs call exchange processing,
The VoIP telephone control terminal transmits, to the VoIP exchange, call failure inspection information for detecting whether or not there is a call failure in the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal to the VoIP exchange. With call failure inspection information transmission means,
Based on the call failure inspection information transmitted from the VoIP telephone control terminal, the VoIP exchange detects a call failure in an IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal, and based on the detection result, the IP A call failure detection means for setting a call failure flag indicating the presence or absence of a call failure on the call line;
The call failure flag set by the call failure detection means, and the telephone number of the public switched telephone network of the transfer destination for transferring a call to the IP call line when there is a call failure in the IP call line Fault information storage means for storing the information in association with the telephone number assigned to the IP telephone line;
When a call exchange processing request is made to the VoIP exchange, a call failure flag corresponding to the telephone number assigned to the IP telephone line scheduled to be connected in the exchange processing request is read with reference to the failure information storage means Call failure determination means for determining whether or not there is a call failure in the IP call line scheduled to be connected based on the read call failure flag;
When the call failure determination means determines that there is a call failure in the IP call line scheduled for connection, the telephone assigned to the IP call line scheduled for connection in the exchange processing request with reference to the failure information storage means Call transfer means for reading out the telephone number of the public switched telephone network corresponding to the number and transferring the call for which the exchange processing request has been made to the public switched telephone line having the read telephone number of the public switched telephone network. An IP telephone network system characterized by the above. The VoIP telephone control terminal further comprises public switched telephone network connection means connected to a public switched telephone network,
The telephone number of the destination public exchange telephone network that the failure information storage means in the VoIP exchange stores in correspondence with the telephone number assigned to the IP telephone line connected to the VoIP telephone control terminal is the VoIP telephone 2. The IP telephone network system according to claim 1, wherein the IP telephone network system is a telephone number assigned to a public switched telephone line connected to the public switched telephone network connecting means of a control terminal. An IP network, connected to the IP network and a key telephone, and connected to the IP telephone control terminal via the IP network and connected to the public switched telephone network. A detour call method executed in an IP telephone network system including a VoIP exchange that performs call exchange processing,
The VoIP telephone control terminal is
Performing a step of transmitting call failure inspection information for detecting whether or not there is a call failure in an IP communication line connecting the VoIP switch and the VoIP telephone control terminal to the VoIP switch at a predetermined time;
The VoIP exchange is
For each IP call line from the VoIP exchange to the VoIP telephone control terminal, a transfer destination public exchange telephone network for transferring a call to the IP call line when there is a call failure in the IP call line Storing a telephone number in a failure information storage unit provided in the VoIP exchange in association with a telephone number assigned to the IP telephone line;
Based on the call failure inspection information transmitted from the VoIP telephone control terminal, a call failure of the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal is detected, and based on the detection result, the call on the IP telephone line is detected. Setting a call failure flag indicating whether there is a failure;
Storing the call failure flag set by the call failure detection means in the failure information storage means in association with a telephone number assigned to the IP call line;
When a call exchange processing request is made to the VoIP exchange, a call failure flag corresponding to the telephone number assigned to the IP telephone line scheduled to be connected in the exchange processing request is read with reference to the failure information storage means Determining whether or not there is a call failure in the IP call line scheduled to be connected based on the read call failure flag;
When the call failure determination means determines that there is a call failure in the IP call line scheduled for connection, the telephone assigned to the IP call line scheduled for connection in the exchange processing request with reference to the failure information storage means Reading the telephone number of the public switched telephone network corresponding to the number, and transferring the call for which the exchange processing request has been made to the public switched telephone line having the read telephone number of the public switched telephone network. A featured detour call method. An IP network, connected to the IP network and a key telephone, and connected to the IP telephone control terminal via the IP network and connected to the public switched telephone network. A VoIP exchange in an IP telephone network system comprising a VoIP exchange that performs call exchange processing,
Based on the call failure inspection information transmitted from the VoIP telephone control terminal, a call failure of the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal is detected, and based on the detection result, the call on the IP telephone line is detected. A call failure detection means for setting a call failure flag indicating whether there is a failure; and
The call failure flag set by the call failure detection means, and the telephone number of the public switched telephone network of the transfer destination for transferring a call to the IP call line when there is a call failure in the IP call line Fault information storage means for storing the information in association with the telephone number assigned to the IP telephone line;
When a call exchange processing request is made to the VoIP exchange, a call failure flag corresponding to the telephone number assigned to the IP telephone line scheduled to be connected in the exchange processing request is read with reference to the failure information storage means Call failure determination means for determining whether or not there is a call failure in the IP call line scheduled to be connected based on the read call failure flag;
When the call failure determination means determines that there is a call failure in the IP call line scheduled for connection, the telephone assigned to the IP call line scheduled for connection in the exchange processing request with reference to the failure information storage means Call transfer means for reading out the telephone number of the public switched telephone network corresponding to the number and transferring the call for which the exchange processing request has been made to the public switched telephone line having the read telephone number of the public switched telephone network. A VoIP exchange in an IP telephone network system. The call failure detection means receives expiration date information included in call failure inspection information transmitted from the VoIP telephone control terminal,
If the call failure inspection information including the next expiration date information is not received within the expiration date indicated by the expiration date information, there is a call failure on the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal. Determining that there is a call failure flag in the call failure flag corresponding to the telephone number assigned to the IP call line in the call failure flag information storage means,
When call failure inspection information including the next expiration date information is received within the expiration date indicated by the expiration date information, there is no call failure on the IP telephone line connecting the VoIP exchange and the VoIP telephone control terminal. The information indicating "no call failure" is set in the call failure flag corresponding to the telephone number assigned to the IP call line in the call failure flag information storage means in the determination. A VoIP exchange in the described IP telephone network system. An IP network, connected to the IP network and a key telephone, and connected to the IP telephone control terminal via the IP network and connected to the public switched telephone network. A VoIP telephone control terminal in an IP telephone network system comprising a VoIP exchange for performing a call exchange process,
Call failure inspection information transmitting means for transmitting, to the VoIP exchange, call failure inspection information for detecting the presence or absence of a call failure in an IP communication line connecting the VoIP exchange and the VoIP telephone control terminal to the VoIP exchange. A VoIP telephone control terminal in an IP telephone network system, comprising: Further comprising outgoing call failure detection means for detecting a call failure in an IP telephone line connecting the VoIP switch and the IP phone control terminal based on response information from the VoIP switch to information sent from the VoIP phone control terminal. The VoIP telephone control terminal in the IP telephone network system according to claim 6. The VoIP telephone control terminal in the IP telephone network system according to claim 6 or 7, further comprising public switched telephone network connection means for connecting the button telephone and the public switched telephone network.   When a call failure is detected by the outgoing call failure detection means, the call originated from the key telephone is detoured to the public switched telephone network via the public switched telephone network connecting means. A VoIP telephone control terminal in the IP telephone network system according to claim 8. Connected to the IP network, the IP network, the key telephone and the personal computer, the VoIP telephone control terminal for controlling the key telephone, the IP telephone control terminal via the IP network and the public switched telephone network A VoIP telephone control terminal in an IP telephone network system comprising a VoIP exchange for performing a call exchange process,
VoIP line control means that is between the button telephone and the IP network and performs conversion and control of protocols of voice signals and control signals related to telephone calls;
Routing control means connected to the personal computer and performing routing control of information transferred between the personal computer and the IP network;
Priority transfer instruction information between the IP network and the VoIP line control means or the routing control means is added to the information input from the VoIP line control means and indicates that priority transfer control is performed, and the VoIP line VoIP telephone information control in an IP telephone network system, comprising: VoIP call information priority output means for outputting information inputted from the control means to the IP network in preference to information inputted from the routing control means Terminal. The VoIP telephone control terminal in the IP telephone network system according to claim 10, wherein the VoIP telephone call information priority output means is:
It is provided with a plurality of connection terminals that are set in advance to be connected to the VoIP line control means or to the routing control means,
The IP network prioritizes information input from a connection terminal set to be connected to the VoIP line control means over information input from a connection terminal set to be connected to the routing control means. A VoIP telephone control terminal in an IP telephone network system. 12. The VoIP telephone control terminal in the IP telephone network system according to claim 10 or 11, wherein the VoIP call information priority output means is:
It is provided with a plurality of connection terminals that are set in advance to be connected to the VoIP line control means or to the routing control means,
For a connection terminal set to be connected to the VoIP line control means, a priority transfer instruction information adding means for adding the priority transfer instruction information to information input from the connection terminal is provided. A VoIP telephone control terminal in a telephone network system. In the VoIP telephone control terminal in the IP telephone network system according to any one of claims 10 to 12,
The VoIP telephone control terminal in an IP telephone network system, wherein the number of IP telephone lines simultaneously processed by the VoIP line control means is 32 lines or less.

Images