JP4417222B2 - Voice quality control system and method, bandwidth control apparatus, and computer program - Google Patents

Description

  The present invention relates to a voice quality control system and method, a bandwidth control device, and a computer program.

A conventional telephone exchange used for an existing telephone network such as a PSTN (Public Switched Telephone Networks) employs a circuit switching system. In the circuit switching system, if congestion occurs due to calls exceeding the number of lines, call loss processing is performed for newly generated calls, so the call volume does not increase beyond a certain level and voice quality deteriorates. There is nothing.
On the other hand, Patent Document 1 describes a technique for selecting a codec to be used in accordance with the state of channel quality at the start of a call.
JP 2001-175282 A

As described above, the conventional telephone exchange employs a circuit switching system, and when a call exceeding the number of lines occurs and congestion occurs, call loss processing is performed for a newly generated call. The call volume does not increase beyond a certain level and the voice quality does not deteriorate. However, in the telephone service using the Internet protocol that has been widespread in recent years, that is, IP telephone (or VoIP: Voice over IP), even if the number of calls and the call volume increase and the network bandwidth is insufficient, New calls were not lost. As a result, network congestion is not eliminated, voice data delay or packet loss occurs, and voice quality degradation becomes obvious.
However, although the technology of Patent Document 1 selects a codec at the start of a call according to the state of the line quality, when the voice quality deteriorates, the congestion of the network is eliminated and the voice quality is improved. I have not done that.

  The present invention has been made in view of such circumstances, and its object is to improve the voice quality by eliminating the network bandwidth shortage when detecting that the voice quality of the IP telephone has deteriorated. A voice quality control system and method, a bandwidth control device, and a computer program are provided.

In order to achieve the above object, the present invention provides a voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol, comprising: establishing a call between terminals connected to the network; Call control means for performing disconnection, voice quality evaluation means for evaluating call voice quality between measurement points on the network to which the terminal belongs, and voice quality as a result of the voice quality evaluation means evaluating between the measurement points And a predetermined voice quality threshold value determined in advance, and it is detected that the voice quality between the measurement points is deteriorated from the predetermined voice quality, the voice quality deterioration is detected. Bandwidth control means for instructing the call control means to reduce the bandwidth used at the measurement point, and the call control means is used by the bandwidth control means. Belonging to the measurement point reduction is instructed band, and, to the terminal being established call, and instructs the reduction in the usable band of a voice packet containing the voice data of the call, the bandwidth control means If the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, a new voice quality degradation is generated from the terminal belonging to the measurement point where the voice quality is detected. The voice quality control system according to claim 1, wherein the call control unit is instructed to regulate a call to reduce a band used by the measurement point .

The present invention also relates to a voice quality control system for maintaining the voice quality of a call on a network using a packet communication protocol, and call control means for establishing and disconnecting a call between terminals connected to the network. Voice quality evaluation means for evaluating the voice quality of a call between measurement points on the network to which the terminal belongs, and voice quality as a result of the voice quality evaluation means evaluating between the measurement points; When it is detected that the voice quality between the measurement points is deteriorated below the predetermined voice quality by comparing with a predetermined voice quality threshold, the bandwidth of the measurement point where the voice quality deterioration is detected is determined. Bandwidth control means for instructing the call control means to reduce the bandwidth, and the call control means is instructed to reduce the bandwidth used by the bandwidth control means. The belonging to the measurement point was, and to the terminal that the call is established, and instructs the reduction in the usable band of a voice packet containing the voice data of the call, the bandwidth control means, the use of the measuring points If the voice quality evaluated as a result of the band reduction instruction has not been improved to a predetermined voice quality, the call established for the terminal belonging to the measurement point where the voice quality degradation is detected is disconnected, and A voice quality control system characterized in that the call control means is instructed to reduce a band used for a measurement point.

Further, the present invention provides a voice quality control system described above, the band control means instructs the call control means to reduce the bandwidth used with lower-priority call, and wherein the.

The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call The bandwidth control device used in the above-mentioned, wherein the voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs, and a predetermined predetermined voice When it is detected that the voice quality between the measurement points is degraded from a predetermined voice quality by comparing with a quality threshold Instructing means for instructing the call control apparatus to reduce a bandwidth used for a voice packet including voice data of a call for the terminal belonging to the measurement point in which deterioration of voice quality is detected and the call is established And when the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the measurement point at which degradation of voice quality is detected The bandwidth control device is characterized in that the call control device is instructed to restrict a call newly generated from a terminal belonging to and to reduce the bandwidth used at the measurement point .
The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call The bandwidth control device used in the above-mentioned, wherein the voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs, and a predetermined predetermined voice When it is detected that the voice quality between the measurement points is degraded from a predetermined voice quality by comparing with a quality threshold Instructing means for instructing the call control apparatus to reduce a bandwidth used for a voice packet including voice data of a call for the terminal belonging to the measurement point in which deterioration of voice quality is detected and the call is established And when the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the measurement point at which degradation of voice quality is detected The bandwidth control device is characterized in that the call control device is instructed to disconnect a call established for a terminal belonging to, and reduce the bandwidth used at the measurement point.

The present invention is also a voice quality control method used in a voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol, wherein the call control means is a terminal connected to the network. A call control step for establishing and disconnecting a call between, a voice quality evaluation means, a voice quality evaluation step for evaluating the voice quality of a call between measurement points on the network to which the terminal belongs, and a bandwidth control means, The voice quality as a result of the evaluation between the measurement points in the voice quality evaluation step is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control means so as to reduce the use band of the measurement point where the degradation of the voice quality is detected Instructed bandwidth control step, and the call control means belongs to the measurement point instructed to reduce the used bandwidth in the bandwidth control step, and the voice data of the call to the terminal for which the call is established A bandwidth reduction instructing step for instructing a reduction in the usage bandwidth of the voice packet including the voice quality, and the speech quality evaluated as a result of the bandwidth control means after the instruction to reduce the usage bandwidth of the measurement point is improved to a predetermined speech quality If not, a call restriction instruction for instructing the call control means to restrict a newly generated call from a terminal belonging to the measurement point in which deterioration of voice quality is detected and to reduce a band used by the measurement point A voice quality control method comprising: steps .
The present invention is also a voice quality control method used in a voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol, wherein the call control means is a terminal connected to the network. A call control step for establishing and disconnecting a call between, a voice quality evaluation means, a voice quality evaluation step for evaluating the voice quality of a call between measurement points on the network to which the terminal belongs, and a bandwidth control means, The voice quality as a result of the evaluation between the measurement points in the voice quality evaluation step is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control means so as to reduce the use band of the measurement point where the degradation of the voice quality is detected Instructed bandwidth control step, and the call control means belongs to the measurement point instructed to reduce the used bandwidth in the bandwidth control step, and the voice data of the call to the terminal for which the call is established A bandwidth reduction instructing step for instructing a reduction in the usage bandwidth of the voice packet including the voice quality, and the speech quality evaluated as a result of the bandwidth control means after the instruction to reduce the usage bandwidth of the measurement point is improved to a predetermined speech quality If not, a call disconnection instructing step for instructing the call control means to disconnect a call established for a terminal belonging to the measurement point where voice quality degradation has been detected and to reduce the bandwidth used by the measurement point And a voice quality control method characterized by comprising:

The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call The voice quality control method used in the bandwidth control apparatus in claim 1, wherein the measurement means obtained as a result of evaluating the measurement results between the measurement points on the network to which the terminal belongs is indicated by the instruction means of the bandwidth control apparatus The audio quality between the measurement points by comparing the audio quality between the points and a predetermined audio quality threshold value determined in advance. Is detected that the voice quality is deteriorated from the predetermined voice quality, and the voice that includes the voice data of the call belongs to the measurement point where the voice quality deterioration is detected and the call is established for the terminal. If the call control apparatus is instructed to reduce the bandwidth used for the packet, and the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point is not improved to a predetermined voice quality, the voice quality is deteriorated. The voice quality control method is characterized in that a call newly generated from a terminal belonging to the measurement point in which the detection is detected is regulated to instruct the call control device to reduce a use band of the measurement point. .
The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call The voice quality control method used in the bandwidth control apparatus in claim 1, wherein the measurement means obtained as a result of evaluating the measurement results between the measurement points on the network to which the terminal belongs is indicated by the instruction means of the bandwidth control apparatus The audio quality between the measurement points by comparing the audio quality between the points and a predetermined audio quality threshold value determined in advance. Is detected that the voice quality is deteriorated from the predetermined voice quality, and the voice that includes the voice data of the call belongs to the measurement point where the voice quality deterioration is detected and the call is established for the terminal. If the call control apparatus is instructed to reduce the bandwidth used for the packet, and the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point is not improved to a predetermined voice quality, the voice quality is deteriorated. The voice quality control method is characterized in that the call control apparatus is instructed to disconnect a call established with respect to a terminal belonging to the measurement point at which detection is detected, and to reduce a use band of the measurement point.

The present invention also provides a computer used in a voice quality control system that maintains the voice quality of a call on a network using a packet communication protocol to establish and disconnect a call between terminals connected to the network. Call control means for instructing the terminal to which a call has been established belonging to a measurement point on the network instructed to reduce the use band and to reduce the use band of a voice packet, to the terminal on the network Voice quality evaluation means for evaluating the voice quality of a call between measurement points, and comparing the voice quality as a result of the voice quality evaluation means evaluating between the measurement points and a predetermined predetermined voice quality threshold When it is detected that the voice quality between the measurement points is lower than the predetermined voice quality, the voice quality deterioration is detected. If the instructed to said call control means to reduce the bandwidth used for the measurement point, the sound quality of the results of the evaluation after the indication of reduction in the usable band of the measurement point is not improved to a predetermined speech quality, Functioning as a bandwidth control means for instructing the call control means to reduce a use bandwidth of the measurement point by restricting a call newly generated from a terminal belonging to the measurement point in which deterioration of voice quality is detected Is a computer program characterized by
The present invention also provides a computer used in a voice quality control system that maintains the voice quality of a call on a network using a packet communication protocol to establish and disconnect a call between terminals connected to the network. Call control means for instructing the terminal to which a call has been established belonging to a measurement point on the network instructed to reduce the use band and to reduce the use band of a voice packet, to the terminal on the network Voice quality evaluation means for evaluating the voice quality of a call between measurement points, and comparing the voice quality as a result of the voice quality evaluation means evaluating between the measurement points and a predetermined predetermined voice quality threshold When it is detected that the voice quality between the measurement points is lower than the predetermined voice quality, the voice quality deterioration is detected. Instructing the call control means to reduce the used bandwidth of the measurement point, and the voice quality as a result of the evaluation after the instruction to reduce the used bandwidth of the measurement point is not improved to a predetermined voice quality, Functioning as a bandwidth control means for instructing the call control means to disconnect a call established for a terminal belonging to the measurement point in which degradation of voice quality has been detected and to reduce the bandwidth used at the measurement point. It is a computer program characterized.

The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call A voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs, and a predetermined predetermined voice Compared with the quality threshold value, the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control device so as to reduce a use band of a voice packet including voice data of a call belonging to the measurement point at which degradation of voice quality is detected and a call is established. If the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point is not improved to a predetermined voice quality, a new one is added from the terminal belonging to the measurement point where the voice quality degradation is detected. The computer program is configured to function as an instruction means for instructing the call control apparatus to restrict calls generated in the network to reduce the bandwidth used at the measurement point .
The present invention also provides a call control apparatus for establishing and disconnecting a call between terminals connected to the network via a network using a packet communication protocol, and the network of measurement items used for voice quality evaluation. A voice quality control system that maintains a voice quality of a call on the network, by connecting a measurement device that collects measurement results in the network and a bandwidth control device that controls a bandwidth of a voice packet that includes voice data of a call A voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs, and a predetermined predetermined voice Compared with the quality threshold value, the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control device so as to reduce a use band of a voice packet including voice data of a call belonging to the measurement point at which degradation of voice quality is detected and a call is established. If the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point is not improved to a predetermined voice quality, the terminal belonging to the measurement point where the voice quality degradation is detected is established. The computer program is configured to function as an instruction unit that instructs the call control device to disconnect a received call and reduce the bandwidth used at the measurement point.

According to the above invention, in the IP telephone service, which is a telephone service using the Internet protocol, when the network quality becomes insufficient due to an increase in the number of calls and the call volume or a failure of the equipment, the voice quality deteriorates. It is possible to reduce network bandwidth by reducing the bandwidth used for voice packets for carrying data. As a result, voice packet delay and packet loss can be eliminated, and voice quality can be improved.
In addition, the bandwidth used for voice packets should be reduced without disconnecting existing calls by changing the codec for calls in progress, changing the voice packet transmission interval, or restricting newly generated calls. It can also be performed by disconnecting a call during a call. Further, by reducing the use bandwidth of voice packets in order from the call with the lowest priority, the influence on the call with the higher priority can be reduced as much as possible.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of a voice quality control system according to an embodiment of the present invention. In the figure, a network N which is an IP (Internet Protocol) network is configured by connecting a plurality of routers and the like, and a router to which a terminal 1 as an IP telephone terminal is connected is a router 2. The router 2, the call control device 3 that controls the IP phone call, and the bandwidth control device 5 that controls the voice data use bandwidth of the IP phone are connected via the network N. The measuring device 4 is connected to the network N via the router 2 and is arranged for each voice quality measuring point. The measurement point can be set to an arbitrary range in which voice quality is desired to be managed collectively, such as the Tokyo area, the Kansai area, and so on.

The terminal 1 is an IP telephone terminal, receives call control from the call control device 3, and makes a call with another terminal 1. Therefore, the terminal 1 establishes a voice path via the network N with another terminal 1 that performs a call, and transmits / receives voice packets through the established voice path. The voice packet is an IP packet including voice data, and the voice data is data obtained by encoding analog voice. The terminal 1 uses a predetermined codec, a codec negotiated between the incoming and outgoing terminals 1, or a codec instructed from the call control device 3 for audio encoding. The codec is an encoding method used when converting voice into data. G711 uses a band of 64 kbps (kbps = kilobits / second) per call, and G729a uses a band of 8 kbps per call. There are G723.1 and the like which use a bandwidth of 6.3 kbps or 5.3 kbps per call.
For call control, SIP (Session Initiation Protocol), H.264, etc. RTP (Real-Time Transport Protocol) can be used as a voice path for a general IP telephone protocol such as H.323.

FIG. 2 is a block diagram showing an internal configuration of the measuring apparatus 4 shown in FIG. 1, and only functional blocks related to the present invention are extracted and shown.
The measuring device 4 includes a control unit 41, a communication unit 42, and a voice quality measuring unit 43. The control means 41 includes a central processing unit (CPU) and various memories, and controls each part, temporarily stores data, transfers data, and the like. The communication unit 42 transmits and receives data via the network N.

The voice quality measurement unit 43 includes a measurement unit 44 and a measurement result notification unit 45.
The measurement means 44 transmits / receives a pseudo voice packet to / from the measurement device 4 installed at the measurement point to be evaluated for voice quality via the router 2, and the measurement result of each measurement item used for voice quality evaluation is obtained. obtain. Measurement items include packet loss, fluctuation (jitter), and delay. Packet loss means that a transmitted packet is lost. Fluctuation refers to fluctuations in packet reception intervals when packets are transmitted at regular intervals. The term “delay” refers to a delay in time from when a packet is transmitted until it is received.

  The measurement result notifying unit 45 transmits to the band control device 5 measurement result information indicating information such as identification information of the arrival / departure measurement points and measurement results of each measurement item by the measurement unit 44. For the identification information of the measurement point, a part of the address information of the terminal 1 such as the telephone number of the terminal 1 belonging to the measurement point and the upper digit of the IP address, and the router identification information such as the IP address and name of the router 2 are used. You can also.

FIG. 3 is a block diagram showing an internal configuration of the bandwidth control device 5 shown in FIG. 1, and only functional blocks related to the present invention are extracted and shown.
The band control device 5 includes a control unit 51, a communication unit 52, a voice quality evaluation unit 53, and a band control unit 56. The control unit 51 includes a CPU and various memories, and controls each unit, temporarily stores data, transfers data, and the like. The communication unit 52 transmits and receives data via the network N.

The voice quality evaluation unit 53 includes a measurement result reception unit 54 and an evaluation calculation unit 55.
The measurement result receiving unit 54 receives measurement result information from the measurement device 4.
The evaluation calculation means 55 calculates the voice quality evaluation based on the measurement result of each measurement item indicated by the received measurement result information, and the calculated evaluation information and the identification information of the measurement point in the measurement result information The evaluation result information including is generated. For the evaluation method of voice quality, R value, PSQM (perceptual speech quality master), PSQM +, PESQ (perceptual evaluation of speech quality), etc. defined by ITU-T (International Telecommunication Union-Telecommunication sector) recommendation are used. Is done. The R value is an objective evaluation method indicated by a value calculated from a cause of deterioration in voice quality, for example, encoding distortion, delay, echo, packet loss, and the like. PSQM is an objective evaluation method for estimating the quality of speech from the difference between signal features of the original speech and degraded speech. PSQM + is an objective evaluation method based on PSQM and further considering degradation due to packet loss, delay, and the like. PSEQ is an objective evaluation method that incorporates effects on packet fluctuation and loss in PSQM.

  The band control unit 56 includes an instruction unit 57. When the instruction unit 57 detects that the voice quality is deteriorated based on the evaluation result information generated by the evaluation calculation unit 55, the instruction unit 57 instructs the reduction of the use band of the voice packet. The instructions for reducing the used bandwidth of voice packets include changing to a codec with a smaller used bandwidth, changing the transmission interval of voice packets, restricting newly generated calls, and disconnecting calls during a call. Also, the instruction to reduce the bandwidth used for the voice packet is given step by step until the voice quality is improved from a call with a low priority to a call with a high priority.

  The reason why the use band is reduced by changing the voice packet transmission interval is as follows. A packet flowing through the network includes a header in which information for routing the packet such as an IP address is set, and a payload in which actual data is set. Therefore, by increasing the voice packet transmission interval, the amount of payload data for setting the actual voice data does not change, but the overhead of the header portion is reduced, so the bandwidth used is reduced.

FIG. 4 is a block diagram showing an internal configuration of the call control device 3 shown in FIG. 1, and only functional blocks related to the present invention are extracted and shown.
The call control device 3 includes control means 31, communication means 32, storage means 33, and call control means 34. The control unit 31 includes a CPU and various memories, and controls each unit, temporarily stores data, transfers data, and the like. The communication means 32 transmits and receives data via the network N.

The storage means 33 stores a priority table and a session table.
The priority table holds priority condition information indicating priority call conditions and priority information. The priority condition information is indicated by a part or all of an outgoing or incoming telephone number, a domain name, an IP address, or any combination thereof.
The session table includes the address information of the caller 1 and callee 1 of the call that is currently being made, the state of the call during a call, ringing, etc., the codec being used, the priority of the call, and the measurement point to which the terminal 1 belongs The identification information of As address information of the terminal 1 on the calling side and the called side, a telephone number, a domain name, an IP address, a combination of an IP address and a port number, and the like are used.

The call control unit 34 includes a call establishment unit 35, a band change instruction receiving unit 36, a band change instruction unit 37, and a call release unit 38.
The call establishing means 35 receives a call request from the calling terminal 1 and establishes a call with the called terminal 1 when the call is not a call subject to call restriction. Then, the requested call information is registered in the session table.
The band change instruction receiving unit 36 receives an instruction to reduce the used band of the voice packet from the band control device 5.
The band change instructing unit 37 instructs the terminal 1 to change to a codec with a smaller used band, to extend a voice packet transmission interval, etc., in order to reduce the used band of the voice packet.
The call release means 38 disconnects a call in an arbitrary state.

FIG. 5 is a diagram illustrating a setting example of the priority table stored in the storage unit 33 of the call control device 3. In the priority table, priority condition information and priority information are set. In the figure, the priority condition information is indicated by a telephone number, a domain name, an IP address, etc. of outgoing or incoming call. For example, a call to a special number such as the called numbers “11x” and “11y” has a priority “1”. In addition, the outgoing call from any calling number starting with “01” indicating the Hokkaido area code, the IP address of the called party is “xxx. ***. ***. ***” (“*” A call having an arbitrary character) and a call having a domain name of the called party “xxx.xxx.go.jp” are indicated to have a priority “2”. Further, it is indicated that a call having “045xxxxxxxx” as a calling number or called number has a priority “3”. Calls with the caller's IP address “yyy. Yyy. ***. ***” and the callee's IP address “zzz.zzz. ***. ***” have priority. The degree is “4”.
By using the above priority table, the highest priority is given to incoming calls to special numbers such as the police and fire department, and important calls such as outgoing and incoming calls from government offices and calls originating from areas where disasters such as earthquakes have occurred. It is possible to increase the priority by assigning stages depending on the type of call, such as making communication the next highest priority. Calls that do not match the conditions registered in the priority table are general calls with the lowest priority.

Next, the operation of the voice quality control system will be described.
FIG. 6 is a diagram showing a connection configuration when attention is paid to two measurement points in the voice quality control system. Here, let two measurement points be measurement point a and measurement point b, respectively. The router 2 at the measurement point a is the router 2a, the measurement device 4 is the measurement device 4a, the router 2 at the measurement point b is the router 2b, and the measurement device 4 is the measurement device 4b.

  The call control device 3 controls a call requested from the terminal 1. The call control means 34 of the call control device 3 stores the address information of the call originating and terminating terminals 1, the call state, the codec in use, the priority, the originating side and the terminating side in the session table in the storage means 33. The identification information of the measurement point indicated by the identification information of the router 2 to which the terminal 1 is connected is written. The terminal 1 can use three types of codecs, G711 (64 kbps), G729a (8 kbps), and G723.1 (6.3 kbps / 5.3 kbps), and normally makes a call using the G711. Shall.

On the other hand, the measuring device 4 periodically measures the voice quality between the router 2 to which it is connected and the other router 2 and notifies the bandwidth control device 5 of the voice quality.
For example, in FIG. 6, the measuring means 44 of the measuring device 4a sends a pseudo voice packet for voice quality evaluation to the measuring device 4b. The pseudo voice packet is an IP packet having the same protocol, the same format, and the same length as the voice packet transmitted and received between the terminal 1 and the terminal. This pseudo voice packet reaches the measuring device 4b via the router 2a and the router 2b. When receiving the pseudo voice packet from the measuring device 4a, the measuring device 4b returns it. In this way, the measuring device 4a receives the pseudo voice packet transmitted from the measuring device 4b via the router 2b and the router 2a. The measuring unit 44 of the measuring device 4a compares the pseudo voice packet transmitted by itself with the pseudo voice packet returned from the measuring device 4b, and obtains the measurement result of each measurement item such as packet loss, fluctuation, and delay. .
The measurement result notifying unit 45 of the measurement device 4a transmits measurement result information including the identification of the measurement point a and the measurement point b and the measurement result information of each measurement item to the bandwidth control device 5.

FIG. 7 is a flowchart showing the operation of the bandwidth control device 5.
The measurement result receiving unit 54 of the bandwidth control device 5 receives the measurement result information from the measurement device 4a (step S100). Then, the evaluation calculation means 55 calculates the voice quality evaluation based on the measurement result of each measurement item indicated by the received measurement result information, and generates evaluation result information (step S150). The instruction unit 57 compares the voice quality indicated by the evaluation result information with a predetermined voice quality threshold value determined in advance, and determines whether or not the voice quality has deteriorated (step S200). If the voice quality indicated by the evaluation result information is better than a predetermined voice quality threshold value determined in advance (step S200: NO), the process ends.

On the other hand, when it is determined that the voice quality indicated by the evaluation result information is lower than a predetermined predetermined voice quality threshold (step S200: YES), the instruction unit 57 measures the measurement point indicated by the evaluation result information. Instruct the terminal 1 in communication belonging to a or the measurement point b to switch to a codec with a smaller bandwidth (step S300). The call control device 3 executes this codec switching instruction to the terminal 1 in response to an instruction from the bandwidth control device 5.
First, the instruction unit 57 instructs the terminal 1 of the call with a low priority to switch the codec to G729a. If it is determined that the voice quality has not improved, the terminal 1 of the call with the next highest priority is instructed to switch the codec to G729a. Thus, until the voice quality is improved, the terminal 1 of the call having a higher priority in a stepwise manner is instructed to switch the codec to G729a. If the voice quality does not improve even if the codec switching to G729a is instructed to the highest priority call that can be instructed to switch the codec, the codec to G723.1 is again sent to the terminal 1 of the low priority call. Instruct switching. If the voice quality does not improve, the codec switching to G723.1 is instructed in a stepwise manner for calls with higher priority until the voice quality is improved or the highest priority at which the codec switching instruction is possible is reached.

If the voice quality is not improved by the codec switching in step S300, the instructing unit 57 instructs the terminal 1 during a call belonging to the measurement point a or the measurement point b to increase the voice packet transmission interval (step S400). ). The call control device 3 executes a packet transmission interval change instruction for extending the voice packet transmission interval to the terminal 1 in response to an instruction from the bandwidth control device 5.
First, the instructing unit 57 instructs the terminal 1 of the low priority call to increase the voice packet transmission interval. When it is determined that the voice quality has not improved, the terminal 1 of the call with the next highest priority is instructed to lengthen the voice packet transmission interval. In this way, the instruction unit 57 transmits voice packets in a stepwise manner to a call with a higher priority until the voice quality is improved or the highest priority at which the voice packet transmission interval can be changed is reached. Instruct to change the interval.

  If the voice quality is not improved due to the change of the voice packet transmission interval in step S400, the instruction unit 57 instructs the call control device 3 from the terminal 1 belonging to the measurement point a or the measurement point b to regulate the incoming traffic. An instruction is given to restrict a newly generated call (step S500). At this time, the instructing unit 57 first instructs to restrict outgoing calls for low priority calls. If it is determined that the voice quality has not improved, the call control device 3 is instructed to restrict the call for the next highest priority call. In this way, the call control of the high priority call is instructed step by step until the voice quality is improved or the highest priority at which the call can be controlled is reached.

  If the voice quality does not improve due to the restriction of the inflow traffic in step S500, the instruction means 57 instructs the call control device 3 to disconnect the terminal 1 that is in communication belonging to the measurement point a or the measurement point b (step S600). At this time, the instructing unit 57 first instructs the call having a low priority to be disconnected. If the voice quality is not improved, the call control device 3 is instructed to disconnect the call with the next highest priority. In this way, instructions for disconnecting calls with higher priority are given step by step until the voice quality is improved or the highest priority that can be disconnected is reached.

FIG. 8 is a flowchart showing the detailed operation of the codec switching instruction in step 300 of FIG.
The instruction unit 57 of the bandwidth control device 5 first determines the first switching codec (step S310). That is, G729a having the next smallest bandwidth after G711 that is normally used is determined as the first switching codec. Subsequently, the instructing unit 57 pays attention to the first priority of the codec switching target (step S320). Here, it is assumed that the lowest priority indicating a general call is the priority for codec switching.

The instructing unit 57 passes the information on the switching codec and the priority currently focused on and the identification information of the router 2a and the router 2b to the call control device 3, and instructs the codec switching control (step S330).
The band change instruction receiving unit 36 of the call control device 3 receives a codec switching control instruction from the band control device 5. Then, the band change instructing unit 37 refers to the session information, and becomes the call terminal or the call terminal of the call of the priority level currently focused on among the active terminals 1 belonging to the measurement point a or the measurement point b. A terminal 1 is identified. Then, the address information of the originating and called terminals 1 in the session information corresponding to the specified call and the priority condition information in the priority table are inquired, and the priority indicated by the bandwidth control device 5 is obtained. Identify the call. Here, since the lowest priority indicating a general call is designated, a call that does not match any priority condition information indicated in the priority table is specified. The band change instruction unit 37 extracts the address information of the terminal 1 on the call origination side and the call destination side of the identified call from the session information. At this time, priority information obtained by the above process may be written in the session table.

  If the priority obtained by referring to the priority table at the time of call establishment request from the terminal 1 is registered in the session table in advance, the priority information in the session table and the bandwidth control device 5 are instructed. The priority information may be queried.

  The band change instructing unit 36 uses the extracted address information to instruct the terminal 1 that is in a call belonging to the measurement point a or the measurement point b to switch the codec to the G729a. Upon receiving the codec switching instruction from the call control device 3 to G729a, the terminal 1 changes the currently used codec from G711 to G729a.

  The instruction means 57 of the bandwidth control device 5 determines whether or not the voice quality has been improved within a predetermined time after instructing the call control device 3 to perform the codec switching control in step S330 (step S340). In other words, the measurement result receiving unit 54 of the bandwidth control device 5 receives measurement result information from the measurement device 4 after the codec switching control instruction. The evaluation calculation means 55 calculates evaluation based on the received measurement result information and generates evaluation result information. The instruction unit 57 compares the voice quality between the measurement point a and the measurement point b indicated by the evaluation result information generated by the evaluation calculation unit 55 with a predetermined voice quality threshold value. If the voice quality indicated by the evaluation result information is better than a predetermined voice quality threshold value determined in advance (step S340: YES), the process is terminated assuming that the voice quality has been improved.

On the other hand, when the voice quality indicated by the evaluation result information is still below the predetermined voice quality threshold value (step S340: NO), it is determined that the voice quality is not improved. In this case, the instructing unit 57 determines whether or not the priority currently focused on is the highest upper limit priority among the priorities that are allowed to be subjected to codec switching (step S350). .
By appropriately setting the upper limit priority allowed for codec switching, codec switching can be performed including or excluding very high priority calls corresponding to police, firefighting, priority / important communications, etc. The scope of the target call can be set to do so.

  If the instructing unit 57 determines that the priority currently focused on is lower than the upper limit priority allowed for the codec switching target, the instruction unit 57 newly sets a priority one higher than the current priority. (Step S360). Here, the instructing unit 57 pays attention to a priority one higher than the priority of the lowest general call. Then, the information from the newly noticed priority and switching codec (G729a) and the identification information of the measurement point a and the measurement point b are transferred to the call control device 3, and the processing from step S330 instructing the codec switching control is performed. Repeat again. Thereby, the band change instructing unit 37 of the call control device 3 is a terminal that is a call terminal or a call terminal of a call with a newly noticed priority among the terminals 1 connected to the router 2a or the router 2b. 1 is specified, and the specified terminal 1 is instructed to switch the codec to G729a. Upon receiving the codec switching instruction from the call control device 3 to G729a, the terminal 1 changes the currently used codec from G711 to G729a.

  The instruction means 57 of the bandwidth control device 5 determines that the voice quality has not been improved to a predetermined threshold value or more within a predetermined time after instructing the codec switching control (step S340: NO), and pays attention now. Is determined to be the upper limit priority allowed as a target for codec switching (step S350: YES), the codec that is instructed to switch among the codecs that can be supported by the terminal 1. Further, it is determined whether or not there is a codec with a smaller bandwidth (step S370). If there is a codec with a lower use band (step S370: YES), the codec with the next lower use band is determined as the switching codec (step S380). That is, G723.1 having a smaller bandwidth than G729a is determined as the switching codec. The bandwidth control device 5 repeats the processing from step S320 for the new switching codec.

  If it is determined in step S370 that there is no codec whose usable band is smaller than the codec instructed to switch among the codecs that can be supported by the terminal 1 (step S370: NO), the instruction unit 57 performs the process shown in FIG. The voice packet transmission interval change process shown in FIG.

FIG. 9 is a flowchart showing the detailed operation of the voice packet transmission interval changing process in step 400 of FIG.
The instruction unit 57 of the bandwidth control device 5 first pays attention to the first priority of the voice packet transmission interval change target (step S410). That is, it is assumed that the lowest priority indicating a general call is the priority of the voice packet transmission interval change target.
The instructing unit 57 passes the voice packet transmission interval and the priority information currently focused on and the identification information of the router 2a and the router 2b to the call control device 3, and instructs the voice packet transmission interval change control (step S420). ). It is assumed that the voice packet transmission interval delivered to the call control device 3 is longer than the voice packet transmission interval currently being executed by the terminal 1.

The bandwidth change instruction receiving means 36 of the call control device 3 receives the voice packet transmission interval change control instruction from the bandwidth control device 5. Then, similarly to step S330 in FIG. 8, the band change instructing means 37 is the calling terminal or the receiving terminal of the call of the priority level currently focused on among the terminals 1 that are in communication belonging to the measurement point a or the measurement point b. And the address information of the terminal 1 on the call origination side and the call destination side of the identified call is obtained.
The bandwidth change instructing means 36 uses the extracted address information of the terminal 1 to deliver the information of the voice packet transmission interval instructed from the bandwidth control device 5 to the terminal 1 in communication belonging to the measurement point a or the measurement point b. Instruct to change the voice packet transmission interval. The terminal 1 that has received the instruction to change the voice packet transmission interval from the call control device 3 changes the voice packet transmission interval to the instructed interval.

  The instruction means 57 of the bandwidth control device 5 determines whether or not the voice quality has been improved within a predetermined time after instructing the call control device 3 to change the voice packet transmission interval in step S420 (step S430). Similar to step S340 in FIG. 8, this is the measurement point a or measurement point indicated by the evaluation result information generated based on the measurement result information received from the measurement after the voice packet transmission interval change control instruction. The voice quality between b and a predetermined voice quality threshold value determined in advance are determined by comparison. When the voice quality indicated by the evaluation result information is better than a predetermined voice quality threshold value determined in advance (step S430: YES), the process ends as the voice quality is improved.

  On the other hand, if the voice quality indicated by the evaluation result information is still below the predetermined voice quality threshold value (step S430: NO), it is determined that the voice quality is not improved. In this case, the instructing unit 57 determines whether or not the priority that is currently focused on is the highest upper limit priority among the priorities that are permitted as a target for changing the voice packet transmission interval ( Step S440).

  When the instructing unit 57 determines that the priority currently focused on is lower than the upper limit priority permitted for changing the voice packet transmission interval, the priority is one higher than the current priority. Attention is newly paid every time (step S450). Then, the information on the priority and the voice packet transmission interval change newly noticed and the identification information of the measurement point a and the measurement point b are transferred to the call control device 3, and the voice packet transmission interval change control is instructed from step S420. Repeat the process again. As a result, the band change instructing unit 37 of the call control device 3 is the terminal 1 that is the call terminal or the call reception terminal of the call with the newly noticed priority among the busy terminals 1 belonging to the measurement point a or the measurement point b. And instruct the specified terminal 1 to change the voice packet transmission interval. The terminal 1 that has received the voice packet transmission interval change from the call control device 3 changes the voice packet transmission interval to the instructed interval.

The instruction means 57 of the bandwidth control device 5 determines that the voice quality has not been improved to a predetermined threshold value or more within a predetermined time after instructing the voice packet transmission interval change control (step S430: NO), and is currently If it is determined that the priority level of interest is the upper limit priority level that is permitted as a target for changing the voice packet transmission interval (step S440: YES), the inflow traffic restriction process shown in FIG. 10 is performed.
Note that the terminal 1 may be instructed to increase the voice packet transmission interval stepwise by appropriately repeating the process of FIG. 9 for longer voice packet transmission intervals.

FIG. 10 is a flowchart showing the detailed operation of the inflow traffic restriction process in step 500 of FIG.
The instruction means 57 of the bandwidth control device 5 first pays attention to the first priority of the inflow traffic restriction target (step S510). In other words, it is assumed that the lowest priority indicating a general call is the priority of the inflow traffic restriction target. The instructing means 57 delivers the priority information currently focused on and the identification information of the measurement point a and the measurement point b to the call control device 3, and instructs inflow traffic regulation (step S520).

  The band change instruction receiving means 36 of the call control device 3 receives an inflow traffic restriction instruction from the band control device 5. Thereby, the call control means 34 considers the call below the received priority among the calls requested | required from the terminal 1 which belongs to the measurement point a or the measurement point b as a call loss. Specifically, it operates as follows. The call control means 34 of the call control device 3 receives a call request signal from the terminal 1 belonging to the measurement point a or the measurement point b. Then, the priority level of the requested call is acquired by referring to the priority table in the storage means 33 based on the address information of the call origination side and the call destination side indicated in the call request signal. If the acquired priority is equal to or lower than the priority instructed from the bandwidth control device 5, the requested call is not accepted and the call is lost.

  The instructing means 57 of the bandwidth control device 5 determines whether or not the voice quality has been improved within a predetermined time after instructing the inflow traffic restriction to the call control device 3 in step S520 (step S530). This is the same as step S340 in FIG. 8. The measurement result information by the measurement after the inflow traffic regulation instruction is received, and between the measurement point a and the measurement point b indicated by the evaluation result information generated based on the measurement result information. The voice quality and a predetermined voice quality threshold value determined in advance are determined by comparison. If the voice quality indicated by the evaluation result information is better than a predetermined voice quality threshold value determined in advance (step S530: YES), the process is terminated as it is because the voice quality is improved.

  On the other hand, when the voice quality indicated by the evaluation result information is still below the predetermined voice quality threshold value (step S530: NO), it is determined that the voice quality is not improved. In this case, the instructing unit 57 determines whether or not the priority currently focused on is the highest upper limit priority among the priorities permitted as a target for inflow traffic regulation (step S540). ).

  If the instructing unit 57 determines that the priority that is currently focused on is lower than the priority of the upper limit that is permitted as a target for inflow traffic regulation (step S540: No), the priority is currently greater than the priority that is currently focused on. A new attention is paid to the next higher priority (step S550). Then, the priority information and the identification information of the measurement point a and the measurement point b that are newly noticed are transferred to the call control device 3, and the process from step S520 for instructing inflow traffic restriction is repeated again. As a result, when the call control means 34 of the call control device 3 receives a call request signal from the terminal 1 belonging to the measurement point a or the measurement point b, the call of the priority or lower that has been newly noticed is regarded as a call loss. To do.

  The instructing means 57 of the bandwidth control device 5 determines that the voice quality has not been improved to a predetermined threshold value or more within a predetermined time after instructing the inflow traffic regulation (step S530: NO), and pays attention now. When it is determined that the priority level is the upper limit priority level that is permitted as a target for inflow traffic regulation (step S540: YES), the busy-call disconnecting process shown in FIG. 11 is performed.

FIG. 11 is a flowchart showing the detailed operation of the call disconnection process in step 600 of FIG.
First, the instruction unit 57 of the bandwidth control device 5 pays attention to the first priority of the call disconnection target (step S610). In other words, it is assumed that the lowest priority indicating a general call is the priority for disconnection of a busy call. The instructing unit 57 delivers the priority information currently focused on and the identification information of the measurement point a and the measurement point b to the call control device 3, and instructs to disconnect the call in progress (step S620).

The band change instruction receiving unit 36 of the call control device 3 receives an instruction for disconnecting a busy call from the band control device 5. Then, similarly to step S330 in FIG. 8, the call release means 38 is the calling terminal or the receiving terminal of the call of the priority level currently focused on among the terminals 1 that are in communication belonging to the measurement point a or the measurement point b. The specified terminal 1 is identified, and the address information of the terminal 1 of the identified caller and destination is obtained.
The call release means 38 uses the extracted address information of the terminal 1 to instruct the disconnecting terminal 1 belonging to the measurement point a or the measurement point b to disconnect the call and release the session. The terminal 1 that has received the disconnection instruction from the call control device 3 releases the call.

  The instruction means 57 of the bandwidth control device 5 determines whether or not the voice quality has been improved within a predetermined time since the call control device 3 was instructed to disconnect the call in step S620 (step S630). This is the same as step S340 in FIG. 8. The measurement point information and the measurement point b indicated by the evaluation result information generated based on this measurement result information are received after receiving the measurement result information after the disconnection instruction of the busy call. And the predetermined voice quality threshold value determined in advance is determined by comparison. If the voice quality indicated by the evaluation result information is better than a predetermined voice quality threshold value determined in advance (step S630: YES), the process is terminated as it is because the voice quality has been improved.

  On the other hand, when the voice quality indicated by the evaluation result information is still below the predetermined voice quality threshold value (step S630: NO), it is determined that the voice quality is not improved. In this case, the instructing unit 57 determines whether or not the priority currently focused on is the highest upper limit priority among the priorities that are permitted as a target for disconnecting a busy call ( Step S640).

  If the instructing unit 57 determines that the priority that is currently focused on is lower than the upper limit priority that is permitted as a target for disconnecting a busy call, the priority is one higher than the priority that is currently focused on. Attention is renewed every time (step S650). Then, the priority information and the identification information of the measurement point a and the measurement point b that are newly noticed are transferred to the call control device 3, and the process from step S620 for instructing disconnection of the busy call is repeated again. As a result, the call release means 38 of the call control device 3 selects the terminal 1 that is the calling terminal or the receiving terminal of the newly focused priority among the terminals 1 that are in communication belonging to the measurement point a or the measurement point b. The specified terminal 1 is instructed to disconnect the call. The terminal 1 that has received the disconnection instruction from the call control device 3 releases the call.

  Then, the instruction unit 57 of the bandwidth control device 5 determines that the voice quality has not been improved to a predetermined threshold value or more within a predetermined time after instructing the voice packet transmission interval change control (step S630: NO), and When it is determined that the priority level currently focused on is the upper limit priority level that is permitted as a target for changing the voice packet transmission interval (step S640: YES), the process is terminated.

Next, a specific method for specifying a call using the quality degradation route is shown below.
<Method using segment to which each terminal belongs>
When the terminal 1 is managed and controlled for each segment or domain, a NAT (Network Address Translation) device is installed in a measurement point corresponding to the segment or domain. The NAT device converts the IP address and port number of the IP packet sent from the device connected to the network under its own to the own IP address and port number and sends it to the external network. It has a NAT function or a NAPT (Network Address Port Translation) function that performs the reverse conversion on the IP packet received from the network and passes it to a device connected to the network under its control.
Then, the measurement device 4 and the terminal 1 are connected under the NAT device, and the measurement device 4 and the terminal 1 are connected to the router 2 via the NAT. As a result, all IP packets (including IP packets including call control signals and voice data) transmitted from the measurement device 4 or the terminal 1 at the same measurement point become the IP address or domain of the NAT device to be connected. To do. In this case, NAT device identification information such as the IP address or domain of the NAT device can be used as the measurement point identification information. For example, if the call between address “172.xxx.xxx.xxx” and address “10.xxx.xxx.xxx” is degraded, a NAT device with address “172.xxx.xxx.xxx” is installed. It is determined that the call between the measured measurement point “Tokyo” and the measurement point “Osaka” where the NAT device with the address “10.xxx.xxx.xxx” is installed is deteriorated.

When restricting the connection restriction of new incoming calls, the call control means 34 of the call control device 3 specifies that the deterioration has occurred due to the IP address of the NAT device set as the address information of arrival and departure in the header of the SIP signal. It is determined whether the call is for the terminal 1 belonging to the measurement point.
When the codec of an existing call whose voice quality is degraded, the packet transmission interval is changed, and the call is disconnected, the IP address of the NAT device set as the address information of arrival / departure in the header of the SIP signal is 1 is registered in the session table as identification information of the measurement point to which 1 belongs, and thereby, it is determined whether or not the call is for the terminal 1 belonging to the measurement point identified as degraded.

<Method using the address of each terminal>
When control is performed for each call, the address information of the terminal 1 belonging to each measurement point is held in the storage unit 33 of the call control device 3. The address information of the terminal 1 is, for example, an IP address, a port number, a telephone number, a domain, and a MAC address.
In the case of restricting the connection restriction of new incoming calls, the call control means 34 of the call control device 3 uses the address information (IP address or calling / departing number) of the incoming / outgoing terminal 1 set in the header of the SIP signal. The information of the measurement point to which 1 belongs is obtained, and it is determined whether or not it is a call of the terminal 1 belonging to the measurement point specified as being deteriorated.
When the codec of an existing call whose voice quality is deteriorated, the packet transmission interval is changed, or the call is disconnected, the measurement point is determined from the address of the terminal 1 set as the arrival / departure address information in the header of the SIP signal. It is acquired and registered in the session table, thereby determining whether or not the call is for the terminal 1 belonging to the measurement point identified as degraded.

  Alternatively, the bandwidth control device 5 specifies address information of a call belonging to a measurement point whose quality is degraded. For example, when it is detected that the voice quality is deteriorated between the measurement point “Tokyo” and the measurement point “Osaka”, the telephone number “03-****-**” of the terminal 1 belonging to the measurement point “Tokyo”. ** ”,..., And the telephone number“ 06-****-**** ”,... Of the terminal 1 belonging to the measurement point“ Osaka ”are identified as degraded. Then, it is compared with the telephone number set as the incoming / outgoing address information in the header of the SIP signal, and it is determined whether or not the call is for the terminal 1 belonging to the measurement point specified as degraded.

As described above, according to the present embodiment, when an IP telephone has a shortage of network bandwidth due to an increase in the number of calls, an increase in call volume, or equipment failure, and voice quality deteriorates, the bandwidth used for voice packets To reduce network congestion. As a result, voice packet delay and packet loss can be eliminated, and voice quality can be improved.
In addition, the bandwidth used for voice packets should be reduced without disconnecting existing calls by changing the codec for calls in progress, changing the voice packet transmission interval, or restricting newly generated calls. It can also be performed by disconnecting a call during a call. Further, by reducing the use bandwidth of voice packets in order from the call with the lowest priority, the influence on the call with the higher priority can be reduced as much as possible.
In addition, the voice quality of the IP phone is measured between the start point and the end point (END-END) of the call, and the voice band is reduced according to the state. There is no need for complicated processing such as measurement.
Also, voice quality is measured, and abnormalities are detected based on the voice quality evaluation value to reduce the voice bandwidth. Therefore, the usable bandwidth is derived from the equipment capacity, and is controlled by comparing with the traffic volume in the network. There is no need, and the complexity of data management related to the registration and change of data related to equipment when the equipment is changed is eliminated.

In the above description, the bandwidth control device 5 calculates the voice quality evaluation based on the measurement results of the respective measurement items received from the measurement device 4, but is the same as the evaluation calculation means 55 of the bandwidth control device 5. By providing the function in the measurement device 4, the bandwidth control device 5 may receive information on evaluation of voice quality from the measurement device 4.
Also, in the above, the call control device 3 is instructed to switch the codec to the terminal 1, change the voice packet transmission interval, and call disconnection, but the bandwidth change instruction means 37 of the call control device 3, The bandwidth control device 5 may be implemented by providing the bandwidth control device 5 with the same means as the call release means 38. Further, each of the call control device 3 and the bandwidth control device 5 may be constituted by a plurality of devices, or these may be constituted by the same device.

  Note that the above-described terminal 1, router 2, call control device 3, measurement device 4, and bandwidth control device 5 have a computer system therein. And the above-mentioned terminal 1, router 2, storage means 33 and call control means 34 of the call control device 3, voice quality measurement means 43 of the measurement device 4, and voice quality evaluation means 53 and bandwidth control means of the bandwidth control device 5 The operation process 56 is stored in a computer-readable recording medium in the form of a program, and the above-described processing is performed by the computer system reading and executing the program. The computer system here includes an OS and hardware such as peripheral devices.

  In addition to ROM, “computer-readable recording medium” refers to a portable medium such as a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, or a storage device such as a hard disk built in a computer system. That means. Furthermore, the “computer-readable recording medium” refers to a volatile memory (RAM) inside a computer system that becomes a client or a system when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structure of the audio | voice quality control system by one embodiment of this invention. It is a block diagram which shows the structure of the measuring apparatus by the embodiment. It is a block diagram which shows the structure of the band control apparatus by the embodiment. It is a block diagram which shows the structure of the call control apparatus by the embodiment. It is a flowchart which shows the example of a setting of the priority table by the embodiment. It is a figure which shows the connection structure at the time of paying attention about the two measurement points in the audio | voice quality control system by the embodiment. It is a flowchart which shows operation | movement of the band control apparatus by the same embodiment. It is a flowchart which shows operation | movement of the band control apparatus by the same embodiment. It is a flowchart which shows operation | movement of the band control apparatus by the same embodiment. It is a flowchart which shows operation | movement of the band control apparatus by the same embodiment. It is a flowchart which shows operation | movement of the band control apparatus by the same embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Terminal 2, 2a, 2b ... Router 3 ... Call control apparatus 4, 4a, 4b ... Measuring apparatus 5 ... Bandwidth control apparatus 31, 41, 51 ... Control means 32, 42, 52 ... Communication means 33 ... Storage means 34 ... Call control means 35 ... Call establishment means 36 ... Band change instruction receiving means 37 ... Band change instruction means 38 ... Call release means 43 ... Voice quality measuring means 44 ... Measuring means 45 ... Measurement result notifying means 53 ... Voice quality evaluating means 54 ... Measurement result receiving means 55... Evaluation calculating means 56... Band control means 57.

Claims (13)

A voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol,
Call control means for establishing and disconnecting a call between terminals connected to the network;
Voice quality evaluation means for evaluating the voice quality of a call between measurement points on the network to which the terminal belongs;
The voice quality as a result of the evaluation between the measurement points by the voice quality evaluation means is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. Bandwidth control means for instructing the call control means to reduce the bandwidth used at the measurement point where voice quality degradation has been detected.
With
The call control means uses a voice packet including voice data of a call belonging to the measurement point instructed to reduce a use band by the band control means and to which the call is established. It indicates the reduction of bandwidth,
The band control means, if the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the terminals belonging to the measurement point where the voice quality deterioration is detected Instructing the call control means to restrict a newly generated call from the measurement point and reduce the bandwidth used by the measurement point;
A voice quality control system characterized by that. A voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol,
Call control means for establishing and disconnecting a call between terminals connected to the network;
Voice quality evaluation means for evaluating the voice quality of a call between measurement points on the network to which the terminal belongs;
The voice quality as a result of the evaluation between the measurement points by the voice quality evaluation means is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. Bandwidth control means for instructing the call control means to reduce the bandwidth used at the measurement point where voice quality degradation has been detected.
With
The call control means uses a voice packet including voice data of a call belonging to the measurement point instructed to reduce a use band by the band control means and to which the call is established. Instructing bandwidth reduction,
The band control means, if the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the terminals belonging to the measurement point where the voice quality deterioration is detected Instructing the call control means to disconnect the established call for reducing the bandwidth used by the measurement point;
Features and be Ruoto voice quality control system that. The bandwidth control means instructs the call control means to reduce the bandwidth used for a low priority call;
The voice quality control system according to claim 1 or 2 , characterized by the above. Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network and measurement items used for voice quality evaluation via a network using a packet communication protocol The bandwidth control used in the voice quality control system for connecting the measurement device and the bandwidth control device for controlling the bandwidth used for the voice packet including the voice data of the call and maintaining the voice quality of the call on the network A device,
The measurement point is compared by comparing the voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. The voice data of the call for the terminal belonging to the measurement point where the degradation of voice quality is detected and the call is established when it is detected that the voice quality during the period is degraded from a predetermined voice quality Instruction means for instructing the call control device to reduce the bandwidth used for voice packets including
Equipped with a,
When the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the instruction means receives from the terminals belonging to the measurement point where the voice quality deterioration is detected. Instructing the call control device to regulate a newly generated call and reduce the bandwidth used by the measurement point,
A bandwidth control apparatus characterized by that. Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network via a network using a packet communication protocol and measurement items used for voice quality evaluation The bandwidth control used in the voice quality control system for connecting the measurement device and a bandwidth control device for controlling the bandwidth used for the voice packet including the voice data of the call and maintaining the voice quality of the call on the network A device,
The measurement point is compared by comparing a voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. Call voice data for the terminal belonging to the measurement point where the voice quality degradation is detected and the call is established, when it is detected that the voice quality between them is degraded from a predetermined voice quality Instructing means for instructing the call control device to reduce a bandwidth used for a voice packet including:
With
When the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, the instruction unit is configured for terminals belonging to the measurement point where the voice quality deterioration is detected. Instructing the call controller to disconnect an established call and reduce the bandwidth used by the measurement point;
A bandwidth control apparatus characterized by that. A voice quality control method used in a voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol,
A call control step in which call control means establishes and disconnects a call between terminals connected to the network;
A voice quality evaluation step for evaluating a voice quality of a call between measurement points on the network to which the terminal belongs;
The bandwidth control means compares the voice quality as a result of the evaluation between the measurement points in the voice quality evaluation step with a predetermined voice quality threshold value determined in advance, and the voice quality between the measurement points is a predetermined voice. A bandwidth control step for instructing the call control means to reduce the bandwidth used at the measurement point where the degradation of voice quality is detected when it is detected that the quality is degraded.
The call control means belongs to the measurement point instructed to reduce the use band in the band control step, and uses a voice packet including call voice data for the terminal for which a call has been established. A bandwidth reduction instruction step for instructing bandwidth reduction;
If the audio quality as a result of the evaluation by the band control means after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined audio quality, the terminals belonging to the measurement point where the audio quality deterioration is detected A call restriction instruction step for instructing the call control means to restrict a newly generated call and reduce the bandwidth used by the measurement point;
A voice quality control method comprising: A voice quality control method used in a voice quality control system for maintaining voice quality of a call on a network using a packet communication protocol,
A call control step in which call control means establishes and disconnects a call between terminals connected to the network;
A voice quality evaluation step for evaluating a voice quality of a call between measurement points on the network to which the terminal belongs;
The bandwidth control means compares the voice quality as a result of the evaluation between the measurement points in the voice quality evaluation step with a predetermined voice quality threshold value determined in advance, and the voice quality between the measurement points is a predetermined voice. A bandwidth control step for instructing the call control means to reduce the bandwidth used at the measurement point where the degradation of voice quality is detected when it is detected that the quality is degraded.
The call control means belongs to the measurement point instructed to reduce the use band in the band control step, and uses a voice packet including call voice data for the terminal for which a call has been established. A bandwidth reduction instruction step for instructing bandwidth reduction;
If the audio quality as a result of the evaluation by the band control means after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined audio quality, the terminals belonging to the measurement point where the audio quality deterioration is detected A call disconnection instructing step for instructing the call control means to disconnect the established call for reducing the bandwidth used by the measurement point;
A voice quality control method comprising: Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network via a network using a packet communication protocol and measurement items used for voice quality evaluation The bandwidth control device in the voice quality control system that connects the measurement device and the bandwidth control device that controls the bandwidth used for the voice packet including the voice data of the call and maintains the voice quality of the call on the network. A voice quality control method used,
Instructing means of the bandwidth control device,
The measurement point is compared by comparing a voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. Call voice data for the terminal belonging to the measurement point where the voice quality degradation is detected and the call is established, when it is detected that the voice quality between them is degraded from a predetermined voice quality wherein instructs the call control device so as to reduce the bandwidth used for voice packet containing,
When the voice quality as a result of evaluation after the instruction to reduce the bandwidth used at the measurement point has not been improved to a predetermined voice quality, a call newly generated from a terminal belonging to the measurement point where the voice quality deterioration is detected To instruct the call control device to reduce the bandwidth used at the measurement point ,
A voice quality control method characterized by the above. Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network via a network using a packet communication protocol and measurement items used for voice quality evaluation The bandwidth control device in the voice quality control system that connects the measurement device and the bandwidth control device that controls the bandwidth used for the voice packet including the voice data of the call and maintains the voice quality of the call on the network. A voice quality control method used,
Instructing means of the bandwidth control device,
  The measurement point is compared by comparing a voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. Call voice data for the terminal belonging to the measurement point where the voice quality degradation is detected and the call is established, when it is detected that the voice quality between them is degraded from a predetermined voice quality Instructing the call control device to reduce the bandwidth used for voice packets including
If the voice quality as a result of the evaluation after the instruction to reduce the bandwidth used at the measurement point is not improved to a predetermined voice quality, a call established for the terminal belonging to the measurement point where the voice quality deterioration is detected Disconnect and instruct the call control device to reduce the bandwidth used by the measurement point;
A voice quality control method characterized by the above. A computer used in a voice quality control system that maintains voice quality of calls on a network using a packet communication protocol,
A voice packet is transmitted to the terminal that establishes and disconnects a call between terminals connected to the network, belongs to a measurement point on the network instructed to reduce the use band, and has a call established. Call control means for instructing the reduction of the use bandwidth of
Voice quality evaluation means for evaluating the voice quality of calls between the measurement points on the network;
The voice quality as a result of the evaluation between the measurement points by the voice quality evaluation means is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control means is instructed to reduce the bandwidth used at the measurement point where voice quality degradation is detected , and the result of evaluation after the instruction to reduce the bandwidth used at the measurement point is If the voice quality has not been improved to a predetermined voice quality, the call newly generated from the terminal belonging to the measurement point where the voice quality degradation is detected is regulated to reduce the use band of the measurement point. Bandwidth control means for instructing the call control means ;
A computer program that functions as a computer program.   A computer used in a voice quality control system that maintains voice quality of calls on a network using a packet communication protocol,
  A voice packet is transmitted to the terminal that establishes and disconnects a call between terminals connected to the network, belongs to a measurement point on the network instructed to reduce the use band, and has a call established. Call control means for instructing the reduction of the use bandwidth of
  Voice quality evaluation means for evaluating the voice quality of calls between the measurement points on the network;
  The voice quality as a result of the evaluation between the measurement points by the voice quality evaluation means is compared with a predetermined voice quality threshold value, and the voice quality between the measurement points is deteriorated from the predetermined voice quality. The call control means is instructed to reduce the bandwidth used at the measurement point where voice quality degradation is detected, and the result of evaluation after the instruction to reduce the bandwidth used at the measurement point is When the voice quality is not improved to a predetermined voice quality, the call established for the terminal belonging to the measurement point where the voice quality degradation is detected is disconnected to reduce the bandwidth used by the measurement point. Bandwidth control means for instructing the control means;
  A computer program that functions as a computer program. Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network via a network using a packet communication protocol and measurement items used for voice quality evaluation The bandwidth control device in the voice quality control system that connects the measurement device and the bandwidth control device that controls the bandwidth used for the voice packet including the voice data of the call and maintains the voice quality of the call on the network. The computer used,
The measurement point is compared by comparing a voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. Call voice data for the terminal belonging to the measurement point where the voice quality degradation is detected and the call is established, when it is detected that the voice quality between them is degraded from a predetermined voice quality When the call control apparatus is instructed to reduce the use bandwidth of the voice packet including the voice quality of the evaluation result after the instruction to reduce the use bandwidth of the measurement point is not improved to a predetermined voice quality, Before a call that is newly generated from a terminal belonging to the measurement point in which deterioration of voice quality is detected is restricted, the bandwidth used at the measurement point is reduced. Instruction means for instructing instructs the call control apparatus,
A computer program that functions as a computer program.   Collecting measurement results in the network of call control devices for establishing and disconnecting calls between terminals connected to the network via a network using a packet communication protocol and measurement items used for voice quality evaluation The bandwidth control device in the voice quality control system that connects the measurement device and the bandwidth control device that controls the bandwidth used for the voice packet including the voice data of the call and maintains the voice quality of the call on the network. The computer used,
  The measurement point is compared by comparing a voice quality between the measurement points obtained as a result of evaluating the measurement result between the measurement points on the network to which the terminal belongs and a predetermined voice quality threshold value determined in advance. Call voice data for the terminal belonging to the measurement point where the voice quality degradation is detected and the call is established, when it is detected that the voice quality between them is degraded from a predetermined voice quality When the call control apparatus is instructed to reduce the use bandwidth of the voice packet including the voice quality of the evaluation result after the instruction to reduce the use bandwidth of the measurement point is not improved to a predetermined voice quality, Prior to reducing the bandwidth used at the measurement point by disconnecting the call established for the terminal belonging to the measurement point where voice quality degradation is detected. Instruction means for instructing the call control apparatus,
A computer program that functions as a computer program.

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