JP5647630B2 - SIP signal regulating device and SIP signal regulating method - Google Patents

Description

  The present invention relates to a technology for regulating SIP signals.

  According to the cited document 1, in the ISDN exchange, a technique is disclosed in which a pre-processing unit is provided before internal processing and reception of a call is regulated before the internal processing is performed.

JP-A-8-79373

  However, compared with such an existing exchange, in a call processing server that processes SIP signal calls using SIP as a protocol, (1) the received SIP signal and its address information are stored and stored. A reception buffer and an event queue, (2) a transmission buffer for storing a SIP signal edited based on call processing, (3) a transmission queue for storing address information of an edited SIP signal to be transmitted, (4 ) Protocol, call processing is performed using a number of resources such as a transaction buffer for performing transaction management for each transmission / reception and for each SIP session.

  In addition, the resource is also consumed for returning an error response to the received SIP signal, and the service on the call processing server in the other route is affected by the failure of the call processing server located in the opposite route. There is also a feature that it is required not to give.

  Accordingly, there is a problem that the single restriction processing based only on the number of restrictions that can be accepted, which is performed in the above-described existing exchange, is insufficient for stable operation of the call processing server.

  The present invention has been made in view of the above problems, and the object of the present invention is to achieve the availability of the provided service while making the best use of the resources of the call processing server.

The SIP signal restriction device according to claim 1, wherein the SIP signal restriction device operates in a call processing server, wherein the SIP signal restriction device accepts a SIP signal and stores SIP signal data related to the SIP signal in a SIP signal storage means. Before starting the call processing for the SIP signal, the SIP signal is regulated based on a first restriction threshold value indicating the number of simultaneous connections allowable in the call processing server, and used by the SIP signal data. have a, a SIP signal regulating means for determining the necessity of further regulation based on the second restriction threshold value indicating an upper limit of the SIP signal storage area proportion of the SIP signal storage means, SIP signals are transmitted And further comprising a transmission queue for each opposing device for storing address information indicating the storage position of the data in the SIP signal storage means, and the SIP signal restriction means When the current SIP signal storage area usage rate exceeds the second restriction threshold and the number of address information stored in the transmission queue exceeds the sixth restriction threshold, the excess amount The address information is released from the transmission queue, and SIP signal data related to the address information is deleted from the SIP signal storage means .

The SIP signal restriction device according to claim 2 is the SIP signal restriction device according to claim 1 , wherein the SIP signal storage means includes a storage means for transmission for storing SIP signal data to be transmitted, and the SIP signal restriction device. The means sets a value larger than the second restriction threshold as a third restriction threshold, and when the current SIP signal storage area usage rate further exceeds the third restriction threshold, the means for the new SIP signal The storage area allocation of the transmission storage means is restricted.

The SIP signal regulation device according to claim 3, in SIP signaling restricting device according to claim 1, further comprising a transaction storage means for storing transaction data relating to transaction of the SIP signal, the SIP signal regulating means, The upper limit of the transaction storage area usage rate of the transaction storage means used by the transaction is set as a fourth restriction threshold value, and the current transaction storage area usage rate exceeds the fourth restriction threshold value. The storage area allocation of the transaction storage means for the transaction data relating to the transaction of the SIP signal is regulated.

The SIP signal restriction device according to claim 4 is the SIP signal restriction device according to claim 2 or 3, wherein the address information of the received SIP signal and the retransmission timer event data set in the retransmission time interval of the SIP signal to be retransmitted And the SIP signal restriction means sets the upper limit number of events stored in the event queue as a fifth restriction threshold, and the current number of events is When the fifth restriction threshold is exceeded, further storage in the event queue of address information of the SIP signal to be retransmitted and retransmission timer event data other than the last generated retransmission timer event data is restricted. It is characterized by doing.

The SIP signal restriction method according to claim 5 is a SIP signal restriction method performed by a call processing server, wherein the call processing server receives a SIP signal and stores SIP signal data related to the SIP signal in a SIP signal storage means. A SIP signal receiving step, and before starting the call processing for the SIP signal, the SIP signal is regulated based on a first regulation threshold value indicating the number of simultaneous connections allowable in the call processing server; have a, a SIP signal regulating determining the necessity of further regulation based on the second restriction threshold value indicating an upper limit of the SIP signal storage area proportion of the SIP signal storage means used by the data, transmitted A transmission queue for each opposing device that stores address information indicating the storage position of the SIP signal data in the SIP signal storage means. In the SIP signal restriction step, the current SIP signal storage area usage ratio exceeds the second restriction threshold value, and the number of address information stored in the transmission queue further satisfies the sixth restriction threshold value. When exceeding, the address information for the excess is released from the transmission queue, and SIP signal data related to the address information is deleted from the SIP signal storage means .

  As described above, according to the present invention, the restriction threshold is set for each resource of the call processing server, and the SIP signal is appropriately restricted based on the individual restriction threshold, so that the resources of the call processing server are maximized. The availability of the provided service can be achieved.

  ADVANTAGE OF THE INVENTION According to this invention, the availability of a provided service can be aimed at, utilizing the resource of a call processing server to the maximum.

It is a figure which shows schematically the whole connection structure of a transfer type | system | group network. It is a figure which shows the functional block structure of a SIP signal control apparatus. It is a figure which shows the control process flow by a 1st control threshold value. It is a figure which shows the control process flow by a 2nd control threshold value. It is a figure which shows the control process result by a 2nd control threshold value. It is a figure which shows the control process flow by a 3rd control threshold value. It is a figure which shows the control process result by a 3rd control threshold value. It is a figure which shows the control process flow by a 4th control threshold value. It is a figure which shows the control process result by a 4th control threshold value. It is a figure which shows the control process flow by a 5th control threshold value. It is a figure which shows the control process result by a 5th control threshold value. It is a figure which shows the control process concept by a 6th control threshold value. It is a figure which shows the control process flow by a 6th control threshold value.

  Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. However, the present invention can be implemented in many different modes and should not be construed as being limited to the description of the present embodiment.

[For transport network]
First, the entire transfer network including the SIP signal restriction device (operating on the call processing server) according to the present embodiment will be described. FIG. 1 is a diagram schematically showing an overall connection configuration of a transfer network.

  The transfer network includes a plurality of call processing servers 1 and a plurality of call routes that are connected to establish communication by SIP negotiation between a plurality of client terminals 5 and / or a plurality of servers (not shown in FIG. 1). A transfer device 3 and a media server 7 are provided.

  When calling or communicating with the client terminal 5b of the desired destination, the call transfer device 3a → the plurality of call processing servers 1a, 1c, 1b from the requesting client terminal 5a to the destination client terminal 5b → A SIP signal for requesting a call connection is transmitted via the call transfer device 3b.

  Then, SIP negotiation is performed between the client terminals 5a and 5b based on the contents of SDP (Session Description Protocol), and if the result is OK, the SIP session is established.

  Thereafter, session information for media such as voice call and video communication is determined, and after establishing a media session used for transmission / reception of the media, the call transfer devices 3a and 3c are not passed through the call processing server 1. , 3b as communication paths, media communication can be performed between the client terminals 5a, 5b.

[SIP signal regulating device]
Next, the SIP signal regulating device according to the present embodiment will be described. FIG. 2 is a diagram illustrating a functional block configuration of the SIP signal restriction device. The SIP signal restriction device 100 operates on the call processing server 1, and includes a signal reception unit 11, a SIP buffer 12, an event queue 13, a call processing unit 14, a restriction processing unit 15, and a restriction threshold storage unit 16. The transmission queue 17, the signal transmission unit 18, and the transaction buffer 19 are mainly configured.

  The signal receiving unit 11 is a SIP signal receiving unit that is executed by one or more receiving threads (the number can be changed). The signal receiving unit 11 receives SIP from the client terminal 5 transmitted from the call transfer device 3 or the call processing server 1 ″. A signal (“●” schematically shown in FIG. 2) is received, and information included in the SIP signal (hereinafter, SIP signal data) is stored in the reception buffer in the SIP buffer 12 and received. A function of storing address information (for example, a pointer value) indicating the storage position of the SIP signal data in the buffer for use in the event queue 13.

  The SIP buffer 12 is a SIP signal storage means having a predetermined storage area secured in advance and composed of buffers for various uses divided into the same size (or different sizes are possible) within the storage area. A function of storing SIP signal data of the received SIP signal in a reception buffer (reception storage means), an opposing call processing server 1 ′ or a media server 7 (generally a server capable of transmitting and receiving SIP signals. It has a function of storing SIP signal data of the SIP signal transmitted to the server 1 ′ in a transmission buffer (transmission storage means).

  The event queue 13 is a reception queue that holds address information of SIP signal data in a FIFO (First In First Out) list structure, and is used to transmit a received SIP signal based on a storage command from the signal reception unit 11. It has a function of temporarily storing address information in the buffer as an event.

  The call processing unit 14 is a SIP signal processing unit and a SIP signal regulating unit that are executed by an event pruning thread or one or more (number of which can be changed) worker threads, and sequentially prunes address information stored in the event queue 13. (Acquires) and reads the SIP signal data from the reception buffer using the address information, and has a function of performing basic internal processing as the call processing server 1.

  This internal processing includes, for example, (1) processing for performing signal processing on the received SIP signal based on the signal protocol, and (2) editing data information in the SIP signal for each opposing call processing server 1 ′. A process for managing the communication state and sequence, (3) a process for converting the logical number of the client terminal 5 into a physical number, (4) a process for determining whether or not a desired service can be provided, and (5) as required. For example, processing for sending a guidance message.

  Also, the function units that depend on services in the call processing unit 14 perform signal analysis / editing in units of a plurality of function units, and are providing services as a whole system from the calling number, whether they are users of their own networks, or providers A service determination for permitting an incoming call or permitting an outgoing call is performed by system analysis such as the above, or by a service determination based on the contents of a service contract associated with the received SIP signal information and the incoming call number. Hereinafter, such internal processing is collectively referred to as “call processing”.

  The call processing unit 14 has a function of requesting the restriction processing unit 15 to determine whether or not the SIP signal needs to be restricted before or after performing the call processing.

  Further, the call processing unit 14 performs the call processing based on the restriction determination result from the restriction processing unit 15 except for performing some kind of error response to the call connection request, and edits (corrects) the call processing. The SIP signal data is stored in the transmission buffer, the address information of the corrected SIP signal data in the transmission buffer is stored in the transmission queue 17, and the SIP signal stored at the time of reception is read from the reception buffer. Has a function to delete. On the other hand, when an error response is made, it has a function of returning that fact to the request transfer device 3 or the call processing server 1 ″ without performing the call processing.

  The restriction processing unit 15 is a SIP signal restriction unit that is executed by the worker thread, and uses each restriction threshold value (first to sixth restriction thresholds described later) read from the restriction threshold value storage unit 16 to call processing unit Before or after the call processing is performed at 14, it has a function of performing restriction determination on the received SIP signal or the SIP signal to be transmitted.

  The restriction threshold storage unit 16 is a restriction threshold storage unit having a certain area secured in advance, and has a function of storing a plurality of restriction thresholds set in advance according to each restriction purpose as a config.

  Similar to the event queue 13, the transmission queue 17 holds address information of SIP signal data in a FIFO list structure, and is a transmission queue provided for each opposing call processing server 1 ′ (that is, for each socket communication). Yes, it has a function of temporarily storing address information in the transmission buffer of the SIP signal to be transmitted by a loading instruction by the call processing unit 14.

  The signal transmission unit 18 is a SIP signal transmission unit that is executed by one or more (the number of which can be changed) transmission threads. The address transmission unit 18 sequentially acquires address information from the transmission queue 17 and uses the address information to transmit a transmission buffer. The modified SIP signal data is read out from the server and transmitted to the opposite call processing server 1 ′.

  The transaction buffer 19 is a data storage means that requires a capacity that is a constant multiple of that of the SIP buffer 12, and unit processing (transaction) required for transmission / reception of a SIP signal for each SIP session for each opposing call processing server 1 ′. ) Has a function of storing transaction data.

  In this embodiment, in order to facilitate understanding of the invention, the restriction processing unit 15 is described separately from the call processing unit 14, but in order to perform restriction processing on the SIP signal, the content of the SIP signal is described. Each restriction determination process performed by the restriction processing unit 15 is preferably a function of the call processing unit 14 because there is a unique feature of the call processing server 1 that involves analysis and therefore must be performed within the call control.

[Outline of call processing server operation]
Here, before describing the restriction process that is a feature of the present invention, an outline of the operation of the call processing server 1 will be described. Note that the description of the operation here is limited to the operation that is considered necessary for explaining the restriction process described later, and the operation of the call processing server in the actual environment is not limited to the following.

  First, the signal receiving unit 11 receives a SIP signal transmitted from the previous call transfer device 3 or the call processing server 1 ″, and the SIP signal data included in the SIP signal is stored in the reception buffer. The address information of the SIP signal data is stored in the event queue 13 for each received SIP signal.

  Next, the call processing unit 14 sequentially acquires address information from the event queue 13 in the early order stored when the call processing is ready, and SIP signal data is acquired from the reception buffer using the address information. Then, call processing is executed. On the program, acquisition processing and call processing are executed in parallel by a plurality of worker threads.

  When the SIP signal subjected to the call processing is subject to transmission without performing an error response to the request source by the call processing unit 14, the SIP signal data is corrected by the call processing. The SIP signal data is stored in the transmission buffer, and the address information for the corrected SIP signal data is stored in the transmission queue 17. At this time, the SIP signal (SIP signal before correction) stored at the time of reception is deleted from the reception buffer.

  Thereafter, the address information is acquired from the transmission queue 17 by the signal transmission unit 18, the corrected SIP signal data is read from the transmission buffer using the address information, and transmitted to the opposite call processing server 1 ′. The

  Here, the corrected SIP signal data stored in the transmission buffer is the state of the call processing server 1 and the subsequent call processing server 1 ′ (for example, when the call processing server 1 ′ fails or when retransmission is not required). Etc.), it is necessary to retransmit the message to the opposite call processing server 1 ′.

  Then, a retransmission timer event data set at the retransmission time interval of the SIP signal is sequentially generated (for example, the first time, the second time,..., The sixth time (last)) by a retransmission timer event management unit, which will be described later. In response to the timer notification when the timer expires in the timer event data, the SIP signal data is reacquired from the transmission buffer each time and is retransmitted to the opposite call processing server 1 ′.

  Thereafter, when the SIP signal data is retransmitted based on the last retransmission timer event data, the call processing server 1 regards it as used and deletes it from the transmission buffer.

[Regulation processing by the first regulation threshold (number of simultaneous connections)]
First, a restriction process when the number of simultaneous connections of SIP signals calculated based on the processing capacity of the call processing server 1 (the maximum number of simultaneous connections or the number of simultaneously connectable SIP signals that can be handled by the call processing server 1) is exceeded. Will be described. The restriction threshold storage unit 16 stores the number of simultaneous connections in advance as a first restriction threshold.

  As shown in FIG. 3, first, in step S101, the call processing unit 14 acquires event information (that is, address information) to be processed from the event queue 13, and then before performing call processing, the call processing server 1, a restriction determination request for confirming the necessity / unnecessity of restriction on the SIP signal data located at the address is transmitted to the restriction processing unit 15.

  Next, in step S <b> 102, the restriction processing unit 15 receives the SIP signal data to be determined from the call processing unit 14, and obtains a first restriction threshold (the number of simultaneous connections) from the restriction threshold storage unit 16.

  Next, in step S103, it is determined whether or not the current number of simultaneous connections in which the number of simultaneous connections so far exceeds the first restriction threshold (the number of simultaneous connections). A restriction-required response message (restriction: required, reason: excess of the number of simultaneous connections) is generated because the number of simultaneous connections in the processing server 1 has been exceeded. If not exceeded, a restriction-unnecessary response message in step S105. (Regulation: unnecessary, reason: number of simultaneous connections not exceeded) is generated.

  Next, in step S106, it is determined whether the SIP signal of the SIP signal data acquired in step S102 is an initial signal, a disconnection signal, or a refresh signal. The number of current simultaneous connections is counted up (+1). In the case of a disconnection signal, the number of current simultaneous connections is counted down (−1) in step S108, and in the case of a refresh signal, the process proceeds to step S109. In the case of the refresh signal, no processing may be performed on the current number of simultaneous connections or 0 may be added in the program.

  Next, in step S109, the response message generated in step S104 or step S105 is returned as a restriction determination result.

  Finally, in step S110, when the received restriction determination result indicates that the restriction is necessary, the call processing unit 14 returns an error response including the reason included in the result to the call transfer apparatus 3 that requested the request, and the restriction determination. If the result does not require regulation, call processing is executed.

  In addition, the content described in () of the said regulation required response message and the said regulation unnecessary response message is an example, and is not limited to them (hereinafter the same). Further, instead of such a message, a regulation identification flag that can identify whether regulation is necessary or not may be used (hereinafter the same).

  Since the number of calls processed per unit time in the call processing server 1 obtained from the calculation result of “(3600 ÷ average hold time) × number of simultaneous connections” and the CPU usage rate are in a linear relationship, such a first As the regulation threshold value, for example, a CPU usage rate can be used.

  Then, when the model traffic is on the linear line and the number of calls processed per certain unit time, for example, 400,000 BHCA is the specification call volume, the part not on the line, the call volume above the specification will be described below. It regulates with other regulation thresholds (second to sixth regulation thresholds).

[Regulation processing by the second regulation threshold (emergency procurement threshold)]
As described above, since the SIP signal data is deleted from the reception buffer after the call processing, if the processing stays in the call processing, the reception buffer is stored by additional storage of the subsequent SIP signal data. There is a fear that the address information of the SIP signal data stays in the event queue 13, and as a result, the transmission / reception of the SIP signal performed between the opposed call processing servers 1 ′ may be stopped.

  In addition, as described above, since the SIP signal data is continuously stored in the transmission buffer in consideration of the necessity for retransmission, when the opposite call processing server 1 ′ fails or a certain time elapses in the retransmission timer. In some cases, the buffer for transmission becomes insufficient due to the continuous storage of the SIP signal data that is no longer required for retransmission, and the address information of the SIP signal data stays in the transmission queue 17 provided for each socket communication (each opposing device). is there.

  That is, due to additional or continuous accumulation of SIP signal data and its address information in the reception buffer, transmission buffer, etc., shortage of the storable area of the SIP buffer 12 and retention of address information in the transmission queue 17 occur. Since this may occur, the storage area of the SIP buffer 12 needs to be urgently procured.

  Therefore, in this case, when the upper limit rate (usage upper limit ratio) of the SIP buffer (for example, 90% of the entire SIP buffer) is exceeded, it is determined that the storage area of the SIP buffer needs to be urgently procured. Then, the use upper limit rate is defined as an emergency procurement threshold, and a regulation process performed using the emergency procurement threshold will be described. In the restriction threshold storage unit 16, the emergency procurement threshold is stored in advance as a second restriction threshold.

  Hereinafter, the case of the reception buffer and transmission queue 17 will be described as an example. In the case of the transmission buffer and transmission queue 17 as well, basically the same restriction process is executed by replacing “for reception” with “for transmission”.

  As shown in FIG. 4, first, in step S <b> 201, the restriction processing unit 15 acquires a second restriction threshold (here, an emergency procurement threshold for a transmission / reception buffer) from the restriction threshold storage unit 16.

  Next, in step S202, the data amount of the received SIP signal data is added to the current transmission / reception buffer usage amount in which the reception buffer usage amount is recorded.

  Next, in step S203, the SIP buffer usage rate (= (current reception buffer usage amount + current transmission buffer usage amount) / total amount of storage area of the SIP buffer 12) becomes the second regulation threshold (emergency procurement threshold). In step S204, the emergency procurement flag is set to ON. If not, in step S205, the flag is set to OFF.

  Next, in step S206, the emergency procurement flag set to ON or OFF is returned to the call processing unit 14 as a restriction determination result.

  Finally, in step S207, when the emergency procurement flag is on, the call processing unit 14 determines that the SIP buffer is approaching a depleted state, and the address information stored in the transmission queue 17 is a predetermined queue length threshold ( When the value exceeds a sixth restriction threshold (to be described later), as shown in FIG. 5, the address information corresponding to the excess from the transmission queue 17 is released so as to be equal to or less than the predetermined queue length threshold, and the release target By deleting the SIP signal data from the transmission buffer, a storable area of the reception buffer (an area that can also be used for the transmission buffer) is urgently procured. On the other hand, when the SIP reception buffer emergency procurement flag is off, call processing is executed.

  Note that when the second regulation threshold is exceeded, the SIP buffer emergency procurement flag is only turned on, it is set to on, and the number of address information in the transmission queue 17 exceeds the sixth regulation threshold. In the case where it is detected, the restriction process of step S207 is executed. A specific example of the restriction process will be described later.

  It should be noted that the SIP signal data and the address information thereof released here may be SIP signals that do not affect the service even if released, such as SIP signals to be retransmitted.

[Regulation processing by the third regulation threshold (new call regulation threshold)]
In the above [Regulation processing by the second regulation threshold (emergency procurement threshold)], the regulation processing for releasing / deleting the SIP signal data and its address information when the emergency procurement threshold, that is, the SIP buffer use upper limit rate is exceeded. explained.

  If the SIP buffer 12 is not assigned to the refresh signal or the disconnect signal at the timing exceeding the emergency procurement threshold, many calls including the new call are incomplete calls (incomplete calls that are not completed from the call to the disconnection). )

  On the other hand, even if the emergency procurement threshold is exceeded, the SIP signal can be stored using the remaining storage area of the SIP buffer 12.

  Therefore, here, even if the emergency procurement threshold is exceeded, the completion call is used because of the use of the scheduled completion call or completion call (hereinafter referred to as the completion call) scheduled for completion of connection with the client terminal 5 of the other party. In contrast, a description will be given of a restriction process for preferentially allocating the remaining resources of the SIP buffer 12 while restricting the allocation of the remaining resources for new calls, thereby suppressing the acceptance of new calls. In the restriction threshold storage unit 16, a new call restriction threshold set in a range exceeding the emergency procurement threshold is stored in advance as a third restriction threshold.

  As shown in FIG. 6, first, in step S301, the restriction processing unit 15 determines whether the SIP signal to be allocated is a new call or a completed call. The third restriction threshold (new call restriction threshold) is acquired from the unit 16.

  Next, in step S303, the data amount of the SIP signal data of the allocation target SIP signal is added to the current transmission buffer usage amount recording the usage amount of the transmission buffer so far.

  Next, in step S304, the SIP buffer usage rate (= (current reception buffer usage + current transmission buffer usage) / total amount of storage area of the SIP buffer 12) is the third restriction threshold (new call restriction threshold). If it exceeds, in step S305, a restriction required response message (regulation: required, reason: new call restriction threshold exceeded) indicating that allocation is not possible is generated. In step S306, a restriction-unnecessary response message (regulation: not necessary, reason: new call restriction threshold not exceeded) indicating that assignment is possible is generated.

  Next, in step S307, the response message generated in step S305 or step S306 is returned as a restriction determination result.

  Finally, in step S308, when the received restriction determination result indicates that restriction is required, the call processing unit 14 responds without storing the SIP signal data of the SIP signal (new call) to be allocated in the transmission buffer. Is returned to the requesting call transfer apparatus 3 or the like, and if the restriction determination result does not require restriction, the SIP signal data is assigned to the remaining resource of the transmission buffer and stored.

  If it is determined in step S301 that the call is a completed call, a restriction-unnecessary response message indicating that allocation is possible is transmitted to the call processing unit 14, and the remaining resources of the transmission buffer are allocated.

  As described above, the completed call is preferentially stored in the remaining resource of the SIP buffer 12, and the allocation of the new buffer to the remaining resource of the transmission buffer is restricted (see FIG. 7). In addition, since it is desirable to handle the new call to the reception buffer in preference to the allocation to the transmission buffer, the call is assigned with priority over that. It is assumed that the refresh signal and the disconnection signal are preferentially allowed.

[Regulation processing by the fourth regulation threshold (transaction new call regulation threshold)]
In the above [Regulation processing based on the third regulation threshold (new call regulation threshold)], the processing for regulating a new call using the usage rate of the SIP buffer has been described. Here, the transaction buffer usage rate is used. A process for restricting the allocation of transaction data required for a new call transaction will be described. In the restriction threshold storage unit 16, a transaction new call restriction threshold indicating a transaction buffer use upper limit rate for a new call is stored in advance as a fourth restriction threshold.

  As shown in FIG. 8, first, in step S401, the restriction processing unit 15 determines whether the allocation target SIP signal is a new call or a completed call. The fourth restriction threshold (transaction new call restriction threshold) is acquired from the unit 16.

  Next, in step S403, the data amount of the SIP signal data of the SIP signal to be allocated is added to the current transaction buffer usage amount recording the usage amount of the transaction buffer 19 so far.

  Next, in step S404, it is determined whether or not the transaction buffer usage rate (= current transaction buffer usage amount / total storage area amount of the transaction buffer 19) exceeds the fourth restriction threshold (transaction new call restriction threshold). If exceeded, a restriction required response message (regulation: required, reason: transaction new call restriction threshold exceeded) is generated in step S405, and if not exceeded, assignment is possible in step S406. A restriction unnecessary response message (regulation: not required, reason: transaction new call restriction threshold not exceeded) is generated.

  Next, in step S407, the response message generated in step S405 or step S406 is returned as a restriction determination result.

  Finally, in step S408, the call processing unit 14 stores, in the transaction buffer 19, transaction data relating to the SIP signal data transaction of the SIP signal (new call) to be allocated when the received restriction determination result requires restriction. Without replying, an error response including the reason included in the response is returned to the requesting call transfer device 3 or the like, and if the restriction determination result does not require restriction, the SIP signal data is assigned to the remaining resource of the transaction buffer 19 .

  If it is determined in step S401 that the call is a completed call, a restriction-unnecessary response message indicating that assignment is possible is transmitted to the call processing unit 14, and the remaining resources of the transaction buffer 19 are assigned.

  As described above, a completed call is preferentially stored in the remaining resource of the transaction buffer 19, and a new call is restricted from being allocated to the remaining resource (see FIG. 9).

  In model traffic at 900,000 BHCA, it is assumed that up to 400,000 BHCA operates as a completed call and the rest operate as an incomplete call. When the fourth restriction threshold (transaction new call restriction threshold) is exceeded, the completed call operates as a completed call because the transaction itself needs to be captured in addition to preferentially allocating the transaction buffer 19 The number of possible transactions needs to be secured.

[Regulation processing by the fifth regulation threshold (event queue registration threshold)]
The event queue 13 stores various information and data such as the retransmission timer event, ACK signal data, timeout timer event, and command execution event in addition to the address information stored in the SIP signal transmission buffer as an event. Is stored (registered).

  Here, processing for restricting the number of events stored in the event queue 13 according to the type of the event will be described. In the restriction threshold storage unit 16, an event queue registration threshold is stored in advance as a fifth restriction threshold.

  As shown in FIG. 10, first, in step S <b> 501, the restriction processing unit 15 acquires a fifth restriction threshold (event queue registration threshold) from the restriction threshold storage unit 16.

  Next, in step S502, the event to be registered is added to the current event registration count in which the event registration count in the event queue 13 is recorded.

  Next, in step S503, it is determined whether or not the current event registration count exceeds the fifth restriction threshold (event queue registration threshold). If so, in step S504, the type of the event to be registered is a retransmission timer. Determine if it is an event.

  Next, in the case of a retransmission timer event, it is determined in step S505 whether or not the retransmission timer event is last. If not, the retransmission timer event can be registered again in step S506. Therefore, in the last case, since there is no possibility of re-registration in step S507, the fifth restriction threshold (event queue registration) is generated. A restriction-unnecessary message is generated so as to be registered even if the threshold is exceeded.

  If it is determined in step S504 that the event is not a retransmission timer event, it is determined in step S508 whether the event to be registered is an event related to a SIP signal.

  In the case of a SIP signal event, in step S509, it is determined whether or not the SIP signal event can be retransmitted. If the SIP signal event can be retransmitted, the SIP signal event can be registered again. Therefore, the process proceeds to step S506, and if it cannot be retransmitted, there is no possibility of re-registration, and the process proceeds to step S507.

  In step S503, if the current event registration count does not exceed the fifth restriction threshold (event queue registration threshold), if the target signal is a retransmission timer event in step S510, the previous retransmission timer event is It is determined whether or not it has already been registered. If it is registered, it is not necessary to register again. Therefore, the process proceeds to step S506. If it is not registered, the process proceeds to step S507.

  Next, in step S511, the response message generated in step S506 or step S507 is returned as a restriction determination result.

  Finally, in step S512, when the received restriction determination result requires restriction, the call processing unit 14 discards the registration target signal without registering it in the event queue 13, and when the restriction determination result does not require restriction, Perform registration.

  That is, when the fifth regulation threshold is exceeded, as shown in FIG. 11A, the SIP signal event that can be retransmitted and the retransmission timer event other than the last can be retransmitted. Therefore, registration to the event queue 13 is not performed. However, if the retransmission timer event is the last, it is registered because it cannot be retransmitted. Also register timeout timer events and command execution events.

  On the other hand, when the fifth restriction threshold (event queue registration threshold) is not exceeded and the registration target signal is a retransmission timer event, the previous retransmission timer event remains as shown in FIG. If it does not remain, register it as congestion and discard it without registration. Note that events other than the retransmission timer event are registered because they have not reached the fifth restriction threshold (event queue registration threshold). Note that the retransmission timer event remaining determination is performed by the retransmission timer event management unit.

[Regulation processing by the sixth regulation threshold (queue length threshold)]
Finally, the sixth restriction threshold used in step S207 will be described in detail below.

  Although partially overlapping with the description in [Regulation processing by the second regulation threshold (emergency procurement threshold)], when communication with the opposite call processing server 1 ′ becomes abnormal, it is impossible to transmit a SIP signal. Thus, when the SIP buffer 12 release trigger is after transmission, the address information of the SIP signal stays in the transmission queue 17 for each socket communication, and therefore the trigger for deletion from the transmission buffer is lost. There is a possibility of depletion.

  For this reason, in the SIP buffer emergency procurement function implemented using the second restriction threshold (emergency procurement threshold), the queue is stored in the transmission queue 17 for each socket communication with respect to the opposite call processing server 1 ′ with abnormal communication. When address information exceeding the long threshold is stacked, the accumulated address information is discarded from the transmission queue 17, and the corresponding SIP signal data is deleted from the transmission buffer, thereby depleting the SIP buffer. To prevent.

  On the other hand, since normal SIP sessions must not be deleted from the SIP buffer, a value equal to or larger than the number that is constantly accumulated in the transmission queue 17 for each socket communication at the time of restart / system switching may be set. Therefore, the queue length stored in the transmission queue 17 for each socket communication at the time of restart / system switching is measured, and the measured value is set as the queue length threshold.

  For example, when the call volume for the call processing server 1 is the same and the call volume for each of the opposite parties is equal, the smaller the opposite number, the larger the number of address information stored in the transmission queue 17, and the larger the opposite number. The queue length threshold is determined according to the number of opposing call processing servers 1 ′ because it is assumed that the number will decrease.

  Specifically, the leftmost part of FIG. 12 shows a case where the address information exceeds the queue length threshold due to a communication error with the opposite side 1. At this time, the SIP signal is not transmitted to the opposite side, and the SIP signal data corresponding to the address information that cannot be swept from the transmission queue 17 is used in the transmission buffer, and the total SIP buffer consumption increases and is compressed. It will be.

  As a result, there is a shortage of reception buffers and transmission buffers that are used for normal communication between the opposing 2 and 4. Therefore, when the second regulation threshold (emergency procurement threshold) is exceeded and the queue length threshold is exceeded, the address information that is stored in the transmission queue 17 for opposite 1 and exceeds the queue length threshold is discarded. At the same time, the SIP signal data corresponding to the address information is deleted from the transmission queue 17.

  Therefore, as described above, in addition to the second restriction threshold (emergency procurement threshold), a queue length threshold (sixth restriction threshold) for restricting the number of address information in the transmission queue 17 is provided, and the emergency procurement threshold is set. A process for restricting only the SIP signal exceeding the queue length threshold in the transmission queue 17 when the number exceeds the limit will be described in detail.

  As shown in FIG. 13, first, in step S <b> 601, the restriction processing unit 15 acquires a sixth restriction threshold (queue length threshold) from the restriction threshold storage unit 16.

  Next, in step S602, it is determined whether or not the queue length (number of address information) based on the address information loaded in the transmission queue 17 exceeds a sixth restriction threshold (queue length threshold). In step S603, a regulation required response message (regulation: required, reason: queue length threshold exceeded) indicating that the queue length threshold has been exceeded is generated. If not exceeded, in step S604, a regulation unnecessary response message (regulation: Not required, reason: queue length threshold not exceeded).

  Next, in step S605, the response message generated in step S603 or step S604 is returned as a restriction determination result.

  Finally, in step S606, when the received restriction determination result indicates that restriction is required and the second emergency procurement threshold is ON, the call processing unit 14 makes the queue length threshold or less as shown in FIG. Release address information from the transmission queue 17 (similar to the above, address information of a SIP signal that does not affect the service even if it is released), delete SIP signal data corresponding to the address information from the transmission buffer, A part of the storage area of the reception buffer is used as a transmission buffer.

[Regarding the order of application of each regulation]
Finally, the order of application of each regulation described so far will be described. First, it is determined whether “first restriction threshold (number of simultaneous connections) <current number of simultaneous connections” (step S103) is satisfied, and if not, the second restriction threshold (emergency procurement threshold) is used. Therefore, the necessity of further regulation is determined.

  Next, it is determined whether “second regulation threshold (emergency procurement threshold) <SIP buffer usage rate” (step S203) is satisfied, and if it is satisfied, the SIP buffer emergency procurement flag is set to ON, Only the transmission queue 17 exceeding the restriction threshold (predetermined queue length threshold) (that is, only the call processing server 1 ′ facing the transmission queue 17) is subject to restriction (step S 207).

  Next, “third restriction threshold (new call restriction threshold) <SIP buffer usage rate” (steps S203 and S304) is satisfied, and / or “fourth restriction threshold <transaction buffer usage rate”. "(Step S404) is determined to be established, and if it is established, the entire system is regulated. However, at this time, only new calls are subject to restriction, and completed calls are excluded from restriction as much as possible (see FIGS. 7 and 9).

  Finally, it is further determined whether “fifth restriction threshold (event queue registration threshold) <current event registration count” (step S504) is satisfied, and if it is satisfied, address information of the SIP signal expected to be retransmitted And the storage of retransmission timer events are restricted (steps S508 and S505).

  In addition, each control process demonstrated above can also be performed independently arbitrarily, respectively, and any 2 or more may be performed.

  As described above, according to the present embodiment, before starting the call processing for the SIP signal, the SIP signal is restricted based on the first restriction threshold value indicating the number of simultaneous connections allowable in the call processing server 1. Since the necessity of further restriction is determined based on the second restriction threshold value indicating the upper limit of the SIP buffer usage rate of the SIP buffer 12 used by the SIP signal data, the resources of the call processing server are utilized to the maximum. Meanwhile, the availability of the provided service can be achieved.

  Further, according to the present embodiment, when the current SIP buffer usage rate exceeds the second restriction threshold and the number of pieces of address information stored in the transmission queue 17 exceeds the sixth restriction threshold, the excess is exceeded. Since the address information corresponding to the address information is released from the transmission queue 17 and the SIP signal data related to the address information is deleted from the SIP buffer 12, the availability of the provided service can be achieved more reliably.

  Further, according to the present embodiment, when a value larger than the second restriction threshold is set as the third restriction threshold, and the current SIP buffer usage rate further exceeds the third restriction threshold, a new SIP is set. Since the storage area allocation of the transmission buffer for the signal is regulated, the priority of the service for the completed call (continuation call) can be increased.

  Further, according to the present embodiment, the transaction buffer usage rate of the transaction buffer 19 used in the transaction is set as the fourth regulation threshold, the current SIP buffer usage rate exceeds the second regulation threshold, When the current transaction buffer usage rate exceeds the fourth restriction threshold, the storage area allocation of the transaction buffer 19 for the transaction data related to the transaction of the new SIP signal is restricted, so the service for the completed call (continuation call) Can be further increased.

  Further, according to the present embodiment, the upper limit number of events stored in the event queue 13 is set as the fifth restriction threshold, and when the current number of events exceeds the fifth restriction threshold, Since further storage of the address information of the SIP signal and retransmission timer event data other than the last generated retransmission timer event data in the event queue 13 is restricted, the availability of the provided service can be further improved.

  Finally, the SIP signal restriction device 100 can be realized by a computer having storage means such as a memory and calculation / control means such as a CPU. In addition, operation processing performed by the apparatus is executed by a program.

DESCRIPTION OF SYMBOLS 1 ... Call processing server 1 '... Opposite call processing server 3 ... Call transfer apparatus 5 ... Client terminal 7 ... Media server 11 ... Signal receiving part (SIP signal receiving means)
12 ... SIP buffer (SIP signal storage means)
13 ... Event queue 14 ... Call processor (SIP signal restricting means)
15 ... Restriction processing part (SIP signal restriction means)
DESCRIPTION OF SYMBOLS 16 ... Restriction threshold memory | storage part 17 ... Transmission queue 18 ... Signal transmission part 19 ... Transaction buffer 100 ... SIP signal control apparatus S101-S110, S201-S207, S301-S308, S401-S408, S501-S512, S601-S606 ... process Step

Claims (5)

In the SIP signal regulating device operating on the call processing server,
SIP signal receiving means for receiving a SIP signal and storing SIP signal data related to the SIP signal in a SIP signal storage means;
Before starting the call processing for the SIP signal, the SIP signal is regulated based on a first regulation threshold value indicating the number of simultaneous connections allowable in the call processing server, and used by the SIP signal data. have a, a SIP signal regulating means for determining the necessity of further regulation based on the second restriction threshold value indicating an upper limit of the SIP signal storage area proportion of the SIP signal storage means,
A transmission queue for each opposing device that stores address information indicating a storage position of the SIP signal data to be transmitted in the SIP signal storage means;
The SIP signal regulating means is
If the current SIP signal storage area usage rate exceeds the second restriction threshold and the number of address information stored in the transmission queue exceeds the sixth restriction threshold, the excess address A SIP signal regulating apparatus , wherein information is released from the transmission queue and SIP signal data related to the address information is deleted from the SIP signal storage means . The SIP signal storage means includes transmission storage means for storing SIP signal data to be transmitted,
The SIP signal regulating means is
A value larger than the second restriction threshold is set as a third restriction threshold, and when the current SIP signal storage area usage rate further exceeds the third restriction threshold, the transmission memory for a new SIP signal is set. 2. The SIP signal restriction device according to claim 1, wherein the storage area assignment of the means is restricted. Transaction storage means for storing transaction data related to the SIP signal transaction;
The SIP signal regulating means is
The upper limit of the transaction storage area usage rate of the transaction storage means used by the transaction is set as a fourth restriction threshold value, and the current transaction storage area usage rate exceeds the fourth restriction threshold value. 3. The SIP signal restriction device according to claim 1, wherein the storage area allocation of the transaction storage means for the transaction data related to the SIP signal transaction is restricted. An event queue that stores address information of the received SIP signal and retransmission timer event data set at a retransmission time interval of the SIP signal to be retransmitted as an event;
The SIP signal regulating means is
The upper limit number of events stored in the event queue is set as a fifth restriction threshold, and when the current number of events exceeds the fifth restriction threshold, the address information of the SIP signal to be retransmitted, 4. The SIP signal regulating apparatus according to claim 2, wherein further storing of retransmission timer event data other than the last generated retransmission timer event data in the event queue is restricted. In the SIP signal restriction method performed in the call processing server,
By the call processing server,
A SIP signal receiving step of receiving a SIP signal and storing SIP signal data related to the SIP signal in a SIP signal storage means;
Before starting the call processing for the SIP signal, the SIP signal is regulated based on a first regulation threshold value indicating the number of simultaneous connections allowable in the call processing server, and used by the SIP signal data. A SIP signal restriction step of determining whether further restriction is necessary based on a second restriction threshold value indicating the upper limit of the SIP signal storage area usage ratio of the SIP signal storage means,
A transmission queue for each opposing device that stores address information indicating a storage position of the SIP signal data to be transmitted in the SIP signal storage means;
In the SIP signal regulation step,
If the current SIP signal storage area usage rate exceeds the second restriction threshold and the number of address information stored in the transmission queue exceeds the sixth restriction threshold, the excess address A SIP signal regulating method, wherein information is released from the transmission queue and SIP signal data related to the address information is deleted from the SIP signal storage means.

Images