JP2006304028A - Network control system and congestion control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid congestion when a congestion state is occurred as to a network control system which provides a telephone call by transferring speech packets through the Internet and a congestion control method. <P>SOLUTION: The network control system includes at least edge routers 3 and 5 and a repeater 4 for transferring speech information between telephone sets 1 and 8 in the form of speech packets through a network 6, an operation monitor server 9, an SIP server 10 making call settings, and a maintenance console 11, and one or both of the edge routers 3 and 5 and repeater 4 are equipped with a processing change means for encoding and decoding the speech packets at a compression rate corresponding to the congestion state of the network 6 when the network 6 occurs the congestion state. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a network control system and a congestion control method for transmitting voice packets over the Internet, also called an IP phone.

  A VoIP (Voice over Internet Protocol) system for transmitting voice packets over the Internet to make a call is also referred to as an IP phone as described above, and various methods have already been proposed and put into practical use. . In this case, QoS (Quality of Service) or the like is applied to preferentially transmit voice packets with respect to other data packets and maintain call voice quality. Further, when a disaster occurs or an event is held, a large number of calls are generated, and as a result, a significant delay in voice packets or voice packets are discarded, and normal calls cannot be made.

  In the conventional circuit switching system, when a large number of calls occur and the circuit switching network becomes congested, the switch is controlled so as not to accept a new call due to outgoing restrictions. In the VoIP system, when a large number of calls are generated and a congestion state occurs in which a large amount of voice packets are transmitted, the voice packets are significantly delayed or discarded, and normal calls cannot be made. In this case, the transfer amount (call amount) of voice packets can be monitored, and when a predetermined value is exceeded, it can be determined that a congestion state has occurred. Then, when congestion occurs, transmission restriction can be performed by the above-described QoS control, admission control, or the like. In that case, many users cannot receive Internet services. As a result, the user who cannot receive the service repeats transmission and disconnection until receiving the service, and further accelerates the congestion state. In order to avoid such a situation, it is conceivable to cope by adding an emergency line or setting a detour route. However, there is a problem that causes an increase in system cost.

As means for avoiding such congestion, conventionally, for example, means for changing a transfer route by notifying another network relay apparatus from a network relay apparatus by detecting a congestion state has been proposed (for example, Patent Documents). 1). In addition, means for monitoring a network state by an edge router and changing a VoIP parameter such as a voice encoding method and a coding rate in a VoIP gateway has been proposed (for example, see Patent Document 2). In addition, the reception side radio base station monitors congestion at the time of reception, and when it is determined that congestion occurs, the transmission side radio base station instructs the transmission side radio base station to change the compression ratio. Means for stabilizing the call quality when congestion occurs by changing the compression rate has been proposed (for example, see Patent Document 3). Further, a means for simply avoiding congestion before the occurrence of congestion has been proposed by changing the coding method when a congestion value of a network is added to a voice packet and transmitted to indicate a congestion state (for example, , See Patent Document 4).
JP 2002-252640 A Japanese Patent Laid-Open No. 2004-72242 JP 2002-354537 A JP 2002-217972 A

  The means proposed in, for example, Patent Document 1 for avoiding congestion in the VoIP system is to change the transfer route, but even if it is effective when a congestion state occurs due to the holding of a specific event, When a disaster occurs, most transfer routes become congested, so there is a problem that the effect of avoiding congestion is small even if the transfer route is changed. The means proposed in the above-mentioned Patent Document 2 detects congestion at the edge router, and controls VoIP parameter change at the VoIP gateway connected to the edge router. Can be unified by a common processing program, but it is not practical to unify all gateways corresponding to end terminals connected to the Internet belonging to the public network. That is, there is a problem that it is impossible to provide a means for avoiding congestion for all users connected to the Internet.

  The means proposed in the above-mentioned Patent Document 3 is for monitoring congestion at the receiving base station. When all other base stations do not have the same function, the voice compression is performed. I can't. Furthermore, when congestion is detected, the voice packet being relayed cannot be compressed by the relay device to reduce the network load. Therefore, when burst traffic occurs, it is necessary to wait for a large amount of voice packets staying in the relay network to flow and the network load to decrease. In addition, since it is necessary to synchronize the transfer rate between the transmitting and receiving base stations in order to acquire the compression rate information of the call packet between the base stations, the voice packet being relayed and transmitted that is transmitted during the synchronization There is a possibility that the receiving base station cannot demodulate the compression rate and lacks or the received voice is distorted. Furthermore, since the control is performed for each call, there is a problem that it is impossible to respond instantaneously at the time of bursty congestion, and synchronization processing is performed for each call, which may temporarily increase the network load.

  Further, the means proposed by the above-mentioned Patent Document 4 monitors the degree of congestion at the repeater, adds the congestion value to the voice packet and transfers it, and encodes it according to the congestion value of the received voice packet at the terminal. Since the method is selected, it is necessary to arrange all terminals to have the same processing function as in the means proposed by Patent Document 2 described above. However, since the terminal has a function according to a user's arbitrary selection, this means for avoiding congestion has an unrealistic problem.

  The present invention solves the above-mentioned problems of the conventional example, and does not depend on the device type of the end terminal, does not need to synchronize the compression rate between the transmission and reception sides, and is effective even during burst traffic. An object is to provide a control means for avoiding high congestion.

  The network control system according to the present invention is a network control system including at least an edge router and a relay device for transferring the voice information between telephones as a voice packet, and either the edge router or the relay device. Or both include processing change means for encoding and decoding the voice packet at a compression rate corresponding to a congestion state in the network.

  A call setting server including at least an edge router and a relay device for transferring the voice information between the telephones as a voice packet and having a call setting means and a call information notification receiving means in the network; In a network control system including an operation monitoring server having a traffic information notification receiving means and a maintenance console, the maintenance console is based on a call congestion notification from the call setting server or a traffic congestion notification from the operation monitoring server. Means for sending a congestion control request to the call setting server, wherein the call setting server receives the congestion control request and notifies either one or both of the edge router and the relay device. The edge router or the relay device includes the congestion control notification. The compression rate in accordance includes a processing means for changing the encoding and decoding of the voice packet.

  Further, the maintenance console can be configured to include means for sending a congestion control request to the call setting server based on disaster detection information from the disaster detection system.

  The congestion control method according to the present invention includes at least an edge router and a relay device for transferring voice information between telephones as voice packets, and performs congestion avoidance when a congestion state occurs in the network. In this case, either or both of the edge router and the relay device include a process of changing the encoding and decoding processing for the voice packet at a compression rate corresponding to the congestion state of the network.

  Further, at least an edge router and a relay device for transferring voice information between telephones as voice packets, a call setting server having call setting means and call information notification receiving means in the network, and traffic information of the network In a congestion control method that includes an operation monitoring server having a notification receiving means and a maintenance console, and performs congestion avoidance when a congestion state of the network occurs, a call congestion notification from the call setting server or from the operation monitoring server Based on the traffic congestion notification, a congestion control request is sent from the maintenance console to the call setting server, and the call setting server responds to one or both of the edge router and the relay device according to the congestion control request. Congestion control notification is performed, and the edge router or the previous In either or both of the relay device, in which includes the step of changing the processing of the encoding and decoding of the voice packet with compressed rate in accordance with the congestion control notification.

  When the congestion state of the network occurs, either one or both of the edge router and the relay device changes the compression rate of the voice packet, and performs the encoding and decoding processes, so that the ADSL modem, the ADSL router, the IP gateway The terminal-side device such as the above does not need to have a configuration for dealing with the occurrence of the congestion state, so that congestion can be avoided without increasing the cost of the system and without performing call regulation. If a congestion state can be predicted in the event of a disaster, a voice packet is sent even if the congestion state is avoided by making a congestion control request from the maintenance console, or even if a congestion state occurs. By changing the encoding and decoding processes for the above, it can be quickly avoided.

  Referring to FIG. 1, the network control system of the present invention is a network control system including at least edge routers 3 and 5 and a relay device 4 for transferring network 6 as voice packets with voice information between telephones 1 and 8. In this case, either one or both of the edge routers 3 and 5 and the relay apparatus 4 are provided with processing change means for encoding and decoding voice packets at a compression rate corresponding to a congestion state in the network.

  The congestion control method of the present invention includes at least the edge routers 3 and 5 and the relay device 4 for transferring the voice information between the telephones 1 and 8 through the network 6 as voice packets, and when the congestion state occurs in the network 6. A congestion control method for performing congestion avoidance, in which one or both of the edge routers 3 and 5 and the relay device 4 perform encoding and decoding processing on voice packets at a compression rate corresponding to the congestion state of the network. It includes the process of changing.

  FIG. 1 is an explanatory diagram of a first embodiment of the present invention, in which 1, 8 are telephones, 2 and 7 are terminal devices such as ADSL modems, ADSL routers, or IP gateways, 3 and 5 are edge routers, 4 Is a relay network, 6 is a core network, 9 is an operation monitoring server, 10 is a SIP server as a call setting server, 11 is a maintenance console, and 12 is a maintenance person. A case where the maintenance console 11 is operated by the maintenance person 12 to enable setting control of the operation monitoring server 9 and the SIP server 10 is shown.

  The SIP server 10 is a server that performs call setting control using SIP (Session Initiation Protocol). The server that performs this call setting control uses, for example, MGCP (Media Gateway Control Protocol) as a call setting control protocol. It is also possible to use a server having the same configuration. The present invention can also be applied to a network configuration that does not include the relay device 4. Further, a larger number of relay devices 4, edge routers 3 and 5, terminal side devices 2 and 7, and telephones 1 and 8 can be provided.

  For example, by dialing the telephone number of the partner telephone 8 from the telephone 1, the telephone number information is transferred to the SIP server 10, and the SIP server 10 searches the address of the partner telephone 8 from the telephone number information. A call can be made between the telephones 1 and 8 by notifying the edge router 3 and calling the other telephone 8 and responding to this call. In addition, one or both of the operation monitoring server 9 and the SIP server 10 are provided with a determination means for occurrence of congestion. In addition, either or both of the edge routers 3 and 5 and the relay device 4 are provided with encoding and decoding means capable of changing the compression rate for the voice packet. Furthermore, means for recognizing the occurrence of a network congestion state can be provided.

  The edge routers 3 and 5 and the relay device 4 change the coding rate and the packet length of the voice packet when the congestion state occurs. For example, the coding rate of the voice data is changed from 64 kbps to 32 kbps when the congestion state occurs. , 16 bps, 8 kbps, etc., and correspondingly, the packet length is also shortened to avoid congestion without restricting the call. It is possible to continue. In that case, congestion can be avoided by adding the above functions to the relay device 4 and the edge routers 3 and 5 as devices on the network side, and the terminal devices 2 and 7 have a unified processing function. There is no need to do this, and various conventional configurations for users are sufficient. When a network congestion state occurs between one of the edge routers 2 and 5 and the relay device 4, only the voice packet transferred in the congestion state occurrence section is changed to a high compression rate and transferred. It is also possible to do.

  FIG. 2 is an explanatory diagram of main parts of the edge routers 3 and 5 in FIG. 1 according to the first embodiment of the present invention, 21 is the edge router, 22 is a connection line, 23 is a packet receiving unit, and 24 is congestion. A determination unit, 25 is a decoding unit, 26 is an encoding unit, 27 is a congestion setting unit, 28 is a transfer function unit, 29 is a packet transmission unit, and 30 is a connection line. The packet receiving unit 23 receives packets from the terminal side devices 2 and 7, and the packet transmitting unit 29 is configured to transmit packets to the core network 6. And a packet transmission unit for transmitting packets to the terminal side devices 2 and 7 are shown, but these configurations are not shown. The relay device 4 can also be configured to have a main part similar to the main part of the edge routers 3 and 5. The configuration including the congestion determination unit 24, the decoding unit 25, the encoding unit 26, and the congestion setting unit 27 constitutes an encoding / decoding process changing unit.

  The packet received by the packet receiving unit 23 is transferred to the congestion determining unit 24. When the congestion determining unit 24 does not determine that the packet is in the congestion state, the packet is transferred to the packet transmitting unit 29 under the control of the transfer function unit 28. Then, the packet transmission unit 29 transmits the packet. When the congestion determination unit 24 determines that the packet is a congestion control notification from the SIP server 10 (see FIG. 1) and determines that the network congestion state has occurred according to the congestion mode of the packet data, the decoding unit 25 is instructed to change the setting of the congestion mode, and the congestion setting unit 27 is instructed to register the address of the receiving edge router obtained from the packet data. Upon receiving the congestion mode setting change instruction, the decoding unit 25 changes to the congestion mode according to the congestion state. This congestion mode corresponds to the congestion information set by the congestion setting unit 27 on a one-to-one basis. The congestion setting unit 27 registers the address of the receiving edge router in the internal setting value. In addition, due to the occurrence of a congestion state, the compression coding of the audio data by the decoding unit 25 and the encoding unit 26 is changed to a high compression rate so that the information can be recognized by the relay device and the other edge router. Is notified in the congestion mode.

  FIG. 3 is an explanatory diagram of the main part of the SIP server according to the first embodiment of the present invention, 41 is a SIP server (10 in FIG. 1), 42 is a connection line, 43 is a receiving unit, 44 is a call congestion monitoring unit, 45 denotes a congestion notification unit, 46 denotes a transmission unit, 47 denotes a connection line, and 48 denotes a congestion control unit. The call information is received by the receiving unit 43 and transferred to the call congestion monitoring unit 44 and the congestion control unit 48. The call congestion monitoring unit 44 monitors whether the call is in a congested state based on the call information and exceeds the predetermined value. In the case of the amount, it is determined that a congestion state has occurred, the congestion notification unit 45 instructs to send a congestion control request, and the sending unit 46 sends it to the maintenance console 11 (see FIG. 1). Note that a known configuration can be applied to the configuration for call setting control between the telephones 1 and 8.

  4 is an explanatory diagram of the maintenance console according to the first embodiment of the present invention, in which 61 is a maintenance console (9 in FIG. 1), 62 is a connection line, 63 is an external input unit, 64 is a congestion display unit, and 65 is an external unit. An output unit, 66 is a connection line, and 67 is a congestion notification unit. When the external input unit 63 receives the congestion notification by the operation monitoring server 9, the SIP server 10, or the maintenance person, the congestion display unit 64 transfers the congestion notification to the congestion notification unit 67. The congestion display unit 64 receives the congestion notification unit 67 and the external output. The congestion notification is transferred to the unit 65, and the external output unit 65 displays the occurrence of congestion for the maintenance person. Congestion avoidance control at the time of congestion occurrence can be set to be performed automatically, or can be set to perform control based on the judgment of the maintenance person. It is possible to perform a control input operation in accordance with the display content.

  FIG. 5 shows a congestion notification flowchart from the SIP server 10 or the operation monitoring server 9 to the edge router. The call congestion notification (A1) from the call congestion monitoring unit 44 of the SIP server 10 or the traffic congestion monitoring of the operation monitoring server 9 is shown. The traffic congestion notification (A2) from the control unit is received by the external input unit 63 of the maintenance console 11 and transferred to the congestion display unit 64, and the call congestion / traffic congestion is displayed on the screen of the display device (A3). The presence or absence of the control setting is determined, and when the automatic congestion control is not set, the maintenance person 12 inputs a congestion control request. When the congestion control request is input or the automatic congestion control is set, the congestion notification unit 67 of the maintenance console 11 sends the congestion control request from the external output unit 65 (A5), and the congestion control unit 48 of the SIP server 10 In response to the congestion control request transferred from the receiver 43, a notification of the congestion mode is sent from the transmitter 46 to the edge router (A6).

  FIG. 6 is a flowchart of processing of the edge router, showing processing at the time of receiving the congestion control notification. If the edge router 3 of FIG. 1 is an edge router on the transmission side, the packet receiving unit 23 of the edge router 2 The received packet is transferred to the congestion determination unit 24. Upon receiving the congestion control notification from the SIP server 10 (B1), the congestion determination unit 24 of the edge router 2 analyzes the congestion control notification to obtain a congestion mode. (B2). If there is no change, the process is terminated (B5). If there is a change, the decoder 25 of the edge router 2 is instructed to change the setting of the congestion mode (B3). ) The address of the receiving edge router for the transmitting edge router is set in the congestion setting unit 27 (B4), and the process is terminated (B5).

  FIG. 7 shows a flowchart of processing of the edge router. When a packet is received by the packet receiving unit 23 of the edge router 3 on the transmission side (C1), the packet is transferred to the congestion determining unit 24, and the congestion determining unit 24 Analysis is performed to determine whether or not the packet is a voice packet (C2). If it is not a voice packet, the process proceeds to step (C8). If it is a voice packet, it is transferred to the decoding unit 25, and the congestion mode setting is decoded to determine whether or not there is congestion (C3). If not, the process proceeds to step (C8). When congestion is indicated, the decoding unit 25 performs decoding processing (C4), and the congestion mode is transferred to the encoding unit 26 together with the decoded packet. The compression rate is, for example, G.I. 711 (64 kbps) and G. 729 (8 kbps) or the like can be applied.

  The encoding unit 26 performs encoding processing at a compression rate according to the congestion mode (C5) and transfers the encoded data to the congestion setting unit 27. The congestion setting unit 27 sets the congestion information as the above-described congestion mode in the transmission packet (C6). For example, in the case of IPv4, this congestion information is set to a value other than that currently used in the protocol field of the header. In the case of IPv6, for example, “00”; no congestion, “01”; light congestion, “10”; medium congestion, using the last 2 bits of the traffic class field (8-bit structure) of the header. “11”; the congestion state can be notified by setting such as severe congestion.

  Then, the congestion setting unit 27 edits the protocol such as changing the packet length value of the IP header or setting the address of the receiving edge router obtained from the setting value in the new header (C7). The packet is transferred to the transfer function unit 28. The transfer function unit 28 selects a transmission destination (C8), transfers the packet to the packet transmission unit 29, and transmits from the packet transmission unit 29 (C9).

  FIG. 8 shows a flowchart of the processing of the relay device. The relay device 4 is configured to have a main part similar to the main part of the edge router shown in FIG. 2, and when the packet is received by the packet receiving unit 23 (D1) Then, it is transferred to the congestion judgment unit 24 of the relay device 4 to determine whether or not it is a voice packet (D2). If it is not a voice packet, the process proceeds to step (D9). Then, it is determined whether or not there is congestion (D3). If it is not congestion, the process proceeds to step (D9). In the case of congestion, the transfer function unit 28 of the relay device 4 is notified of the transfer destination of the transmission packet (D4), and the congestion judgment unit 24 of the relay device 4 decodes the address of the receiving edge router, It is determined whether or not the packet transfer destination is congested (D5). If it is congested, the process proceeds to step (D10). If not congested, the decoding unit 25 of the relay apparatus 4 sets the compression rate corresponding to the congested state. The decoding process is performed (D6), and the encoding unit 26 of the relay apparatus 4 encodes the decoded packet at a normal compression rate because the packet transfer destination is not congestion (D7), and the congestion setting unit 27 Forward to. The congestion setting unit 27 edits the protocol including the change of the packet length value of the IP header (D8) and transfers the packet to the packet transmission unit 29.

  If the received packet in the packet receiving unit 23 of the relay device 4 is not a voice packet or does not indicate a congestion state, the transfer function unit 28 of the relay device 4 selects the transfer destination of the transmission packet (D9 In addition, a packet when the transfer destination of the transmission packet is not congested and a packet subjected to protocol editing are transmitted from the packet transmission unit 29 to the adjacent relay device or the receiving edge router (D10). .

  FIG. 9 shows a flowchart of the reception processing of the edge router. The receiving edge router (the edge router 3 in FIG. 1 is the transmitting side, the edge router 5 is the receiving side) Similar to the edge router, the packet receiving unit 23 receives the packet (E1), and the congestion judgment unit 24 determines whether the packet is a voice packet (E2). If not, the process proceeds to step (E7). If the packet is a voice packet, the congestion information of the packet is decoded to determine whether or not the packet is congested (E3). If it is not congested, the process proceeds to step (E7). If congested, it is transferred to the decoding unit 25 to perform decoding processing corresponding to the congestion state (E4), and the audio data of the decoded audio packet is encoded. 26, and encode (E5), transfer to the congestion setting unit 27, edit the protocol (E6), transfer to the transfer function unit 28, select the transfer destination of the transmission packet (E7), Transmission is performed from the transmission unit 29 (E8).

  Even when no congestion control request is input from the maintenance person 12, the maintenance console 11 can notify the call congestion from the SIP server 10 or the operation monitoring server if automatic congestion control is set in the congestion display unit 64. When the traffic congestion notification from 9 is received by the external input unit 63 and transferred to the congestion display unit 64, the congestion display unit 64 confirms the setting of the automatic congestion control. The request is transferred to the congestion notification unit 67. The congestion notification unit 67 processes the congestion control request and transfers it to the external output unit 65. The external output unit 65 can be configured to transmit a congestion control request to the SIP server 10.

  Further, in the edge routers 3 and 5, by providing a function capable of recognizing the occurrence of the congestion state of the network by increasing or discarding the transmission delay of the voice packet, without receiving the congestion control notification from the SIP server 10, Means for avoiding congestion by changing the compression rate for voice packets can be provided.

  FIG. 10 is an explanatory diagram of Embodiment 2 of the present invention. The same reference numerals as those in FIG. 1 denote the same parts, and 13 is a disaster detection system. When the disaster detection system 13 collects various types of disaster occurrence information and detects the occurrence of a disaster, the disaster detection system 13 notifies the maintenance console 11 of the disaster information. The maintenance console 11 displays this disaster information and notifies the maintenance person 12 and starts the congestion control by the operation of the maintenance person 12 or determines the received disaster information and automatically starts the congestion control. Can be configured to. The disaster information includes, for example, a narrow range of disasters and a wide range of disasters. When a narrow range of disasters occur, congestion control is started only when call congestion / traffic congestion occurs, and a wide range of disasters occur. At the time of occurrence, it is expected that congestion will occur, so it is also possible to control to start congestion control.

  FIG. 11 shows a sequence chart when the first condition is satisfied. This first condition is a condition for inputting a congestion control request from the maintenance person 12 to the maintenance console 11. The telephone 1 in FIG. 10 is the telephone on the transmission side, and the edge router 3 is the transmission side. An edge router, an edge router 5 is a receiving-side edge router, and a telephone 8 is a receiving-side telephone. The transmitting-side telephone 1 and the receiving-side telephone 8 are also shown. Similarly, a terminal-side device (ADSL modem / (ADSL router / IP gateway) 2 and 7 are also shown as both the transmitting side and the receiving side, and the receiving side edge router 5 and the transmitting side edge router are used separately for sending and receiving. And information transfer among the SIP server 10, the operation monitoring server 9, the maintenance console 11, and the maintenance person 12. The first condition is a condition in which no disaster information is received from the disaster detection system, and can be applied to the configuration shown in FIG.

  Call information is notified from the IP network to the SIP server 10, and traffic information is notified to the operation monitoring server 9. If the SIP server 10 determines that call congestion has occurred when the call volume exceeds a predetermined value according to the call information, it notifies the maintenance console 11 of the call congestion. If the operation monitoring server 9 determines that traffic congestion occurs when the traffic information exceeds a predetermined value based on the traffic information, the operation monitoring server 9 notifies the maintenance console 11 of traffic congestion. The maintenance console 11 displays call congestion and traffic congestion on the congestion display section 64 (see FIG. 4).

  The maintenance person 12 recognizes the congestion of the IP network based on the display contents of the maintenance console 11 and presses a send button for the congestion control request provided in the maintenance console 11 or sends a congestion control request. By inputting, a congestion control request is input to the maintenance console 11. In this case, it is also possible to make a congestion control request in a plurality of stages corresponding to the degree of the congestion state. The maintenance console 11 transmits a congestion control request to the SIP server 10 in response to a congestion control request from the maintenance person 12.

  At this time, when the telephone number of the receiving telephone 8 is dialed from the transmitting telephone 1, the SIP server 10 performs call setting processing, which is not shown. The terminal device 2 on the transmission side encodes the voice signal and transfers it to the edge router 3 on the transmission side. The edge router 3 has the configuration shown in FIG. 2 described above. When the congestion state does not occur, the edge router 3 transmits an encoded voice packet similar to that in the conventional example, and receives the receiving edge router 5 and the terminal side device. 7 is transferred to the telephone 8 on the receiving side to make a call. Further, as described above, when the edge router 3 receives the congestion control notification from the SIP server 10 due to the occurrence of the congestion state, the voice data encoded from the terminal side device 2 is decoded, and high compression is performed according to the content of the congestion control notification. The voice packet including the congestion information is transmitted to the edge router 5 or the relay device 4 on the receiving side after encoding at the rate.

  When the receiving edge router receives the voice packet encoded at this high compression rate, it decodes the high compression rate according to the congestion information added to the voice packet, encodes it to the normal compression rate, To the terminal side device. The terminal device on the receiving side sends out the voice data by the reverse processing in the terminal device on the transmitting side to the telephone on the receiving side. Therefore, when the congestion state occurs, the edge routers 3, 5 or the relay device 4 encode the voice data at a high compression rate according to the congestion information added to the voice packet, and further shorten the packet length. Since voice packets are transferred by such processing, congestion can be avoided in the IP network without restricting calls.

  FIG. 12 shows a sequence chart when the second condition is satisfied. This second condition is a case where automatic congestion control is set in the maintenance console. The maintenance console 11 performs display by the congestion display unit 64 (see FIG. 4) for the maintenance person 12 when congestion occurs. Even if the congestion control request from 12 is not input, the congestion control request is sent to the SIP server 10 by the determination processing in the congestion display unit 64. Other processing operations are the same as in the case shown in FIG. Therefore, even when the maintenance person 12 is not present, it is possible to avoid congestion by controlling the decoding and encoding of the edge router and the relay device to be changed according to the congestion state when the congestion state of the IP network occurs. In the case of the second condition, as in the case of the first condition, the disaster occurrence information from the disaster detection system 13 is not received by the maintenance console 11, so the configuration shown in FIG. It can also be applied to cases.

  FIG. 13 shows a sequence chart when the third condition is satisfied. The third condition is a condition in which the edge routers 3 and 5 have a processing function corresponding to the congestion state and enable congestion control without receiving a congestion control request from the SIP server 10. 3 and 5 have a function of decoding and encoding corresponding to the congestion mode. For example, when the edge routers 3 and 5 receive the congestion control notification from the SIP server 10 and the congestion mode setting has already been changed to the content corresponding to the congestion state, the congestion control notification from the SIP server 10 is received. This is a case where it is not necessary. Further, regarding the terminal side device such as a telephone, an ADSL modem, the receiving side edge router, the transmitting side edge router, the SIP server, the operation monitoring server, the maintenance console, and the maintenance person, the same relationship as the case shown in FIGS. It is what you have.

  The sending edge router is equipped with a function that can determine that the IP network is congested based on the transmission delay information of the voice packet, etc., and the voice packet decoding process and high compression according to the congestion mode Encoding is performed according to the rate, and the protocol is edited, and the voice packet with the congestion information added is transmitted to the relay apparatus or the receiving edge router. The receiving edge router performs a decoding process of the voice packet at a high compression rate according to the congestion information added to the received voice packet, and subsequently performs an encoding process at a normal compression rate. Further, the protocol is edited, and after returning to a protocol such as RTP (Realtime Transport Protocol) used in the IP network, the voice packet is transmitted to the terminal side device (ADSL modem / ADSL router / IP gateway). This terminal side device decodes the voice packet at a normal compression rate and transmits it to the telephone on the receiving side.

  Call information is notified from the IP network to the SIP server 10, and traffic information is notified to the operation monitoring server 9. When the SIP server 10 detects call congestion from the call information, a call congestion notification is sent to the maintenance console 11, and when the operation monitoring server 9 detects traffic congestion from the traffic information, the traffic congestion notification is sent to the maintenance console 11. Done. The maintenance console 11 displays call congestion and traffic congestion to the maintenance person, but does not transmit a congestion control request to the SIP server 10. Such processing is performed, and congestion can be avoided by the processing function of the edge router. In the case of the third condition, as in the case of the first condition, the disaster occurrence information from the disaster detection system 13 is not received by the maintenance console 11, so that the configuration shown in FIG. It can also be applied to cases.

  FIG. 14 shows a sequence chart when the fourth condition is satisfied. The fourth condition is that, in FIG. 10, when the maintenance console 10 has not received the traffic congestion notification from the operation monitoring server 9 and has not received the call congestion notification from the SIP server 10, When a disaster occurrence notification is received from the system 13 and a congestion state is predicted, the maintenance operator 12 operates the maintenance console 11 to input a congestion control request. In the case of the fourth condition, a disaster occurrence notification is received from the disaster detection system 13 by the maintenance console 11, and the disaster occurrence state is displayed on the congestion display section 64 (see FIG. 4) of the maintenance console 11, and this display content is displayed. Based on this, when the maintenance person 12 predicts the occurrence of a congestion state, the maintenance person 12 inputs a congestion control request to the maintenance console 11.

  The maintenance console 11 sends a congestion control request to the SIP server 10, and the SIP server 10 sends a congestion control notification to the transmitting edge router 3 (see FIG. 10). As a result, the transmitting-side edge router 3 transfers the voice packet encoded at a high compression rate corresponding to the congestion state to the receiving-side edge router 5, and the receiving-side edge router 5 transmits the voice packet encoded at the high compression rate. Is encoded and transferred at a rate for a normal terminal device, and the terminal device decodes and transfers it to the telephone. The SIP server 10 receives a call information notification from the IP network, and the operation monitoring server 9 receives a traffic information notification.

  FIG. 15 shows a sequence chart when the fifth condition is satisfied. The fifth condition is that, in FIG. 10, when the maintenance console 10 has not received the traffic congestion notification from the operation monitoring server 9 and has not received the call congestion notification from the SIP server 10, This is a condition for receiving a disaster occurrence notification from the system 13 and performing congestion control by the judgment processing of the maintenance console 11. Therefore, even when the congestion control request from the maintenance person 12 in FIG. 14 is not input, the congestion control request is sent from the maintenance console 11 to the SIP server 10 by the disaster occurrence notification. Since the processing of each part is the same as that shown in FIG.

It is explanatory drawing of Example 1 of this invention. It is explanatory drawing of the principal part of the edge router of Example 1 of this invention. It is explanatory drawing of the principal part of the SIP server of Example 1 of this invention. It is explanatory drawing of the principal part of the maintenance console of Example 1 of this invention. It is a congestion notification flowchart to the edge router of Example 1 of the present invention. It is a flowchart of the process of the edge router of Example 1 of this invention. It is a flowchart of the process of the edge router of Example 1 of this invention. It is a flowchart of a process of the relay apparatus of Example 1 of this invention. It is a flowchart of the reception process of the edge router of Example 1 of this invention. It is explanatory drawing of Example 2 of this invention. It is a sequence chart at the time of 1st condition satisfaction. It is a sequence chart at the time of 2nd condition satisfaction. It is a sequence chart at the time of 3rd condition satisfaction. It is a sequence chart at the time of 4th condition satisfaction. It is a sequence chart at the time of 5th condition satisfaction.

Explanation of symbols

1,8 Telephone 2,7 Terminal side equipment (ADSL modem, ADSL router, IP gateway)
3, 5 Edge router 4 Relay device 6 Core network 9 Operation monitoring server 10 SIP server 11 Maintenance console

Claims (5)

In a network control system that includes at least an edge router and a relay device for transferring voice information between telephones as a voice packet,
Either one or both of the edge router and the relay device includes a processing change unit for encoding and decoding the voice packet at a compression rate corresponding to a congestion state in the network. . A call setting server including at least an edge router and a relay device for transferring voice information between telephones as voice packets in the network, and having call setting means and call information notification receiving means in the network; and traffic of the network In a network control system including an operation monitoring server having an information notification receiving means and a maintenance console,
The maintenance console includes means for sending a congestion control request to the call setting server based on a call congestion notification from the call setting server or a traffic congestion notification from the operation monitoring server,
The call setting server includes means for receiving the congestion control request and performing congestion control notification to either one or both of the edge router and the relay device,
The network control system according to claim 1, wherein the edge router or the relay apparatus includes processing change means for encoding and decoding the voice packet at a compression rate according to the congestion control notification.   3. The network control system according to claim 2, wherein the maintenance console includes means for sending a congestion control request to the call setting server based on disaster detection information from the disaster detection system. In a congestion control method that includes at least an edge router and a relay device for transferring a voice information between telephones as a voice packet, and that avoids congestion when a congestion state occurs in the network,
Congestion control characterized by including a process of changing encoding and decoding processing for the voice packet at a compression rate corresponding to the congestion state of the network in either one or both of the edge router and the relay device Method. At least an edge router and a relay device for transferring voice information between telephones as voice packets, a call setting server having call setting means and call information notification receiving means in the network, and traffic information notification of the network In a congestion control method including an operation monitoring server having a receiving means and a maintenance console, and performing congestion avoidance when a congestion state of the network occurs,
A congestion control request is sent from the maintenance console to the call setting server based on a call congestion notification from the call setting server or a traffic congestion notification from the operation monitoring server, and the call setting server sends the congestion control request according to the congestion control request. Congestion control notification is sent to one or both of the edge router and the relay device, and either one or both of the edge router or the relay device follows the congestion control notification according to the congestion control notification. A congestion control method comprising a step of changing encoding and decoding processing for the voice packet at a compression rate.

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