KR20090044143A - Session control method and system to prevent overload of in ims system - Google Patents

Abstract

The present invention relates to a session control method and system for preventing overload in an IMS (IP Multimedia Subsystem) system.

According to the present invention, the session control server of the session control system for preventing overload to generate and register the call blocking information for limiting the session setting for the transmission and reception IP causing the overload in the network, based on the registered call blocking information The soft switch controls the session establishment request of the subscriber station for the registered transmission / reception IP.

Therefore, it is possible to provide a stable service to the subscribers by preventing the overload of the network and the system connected to the network.

IMS, soft switch, BcN, tolerance

Description

Session control method and system to prevent overload in IMS system and its system

The present invention relates to a method and system for controlling a service session of a subscriber for preventing overload in an IMS scheme for providing a broadband convergence network (BcN) service based on the Internet.

Broadband convergence network (BcN) is a network constructed by using internet-based multi-protocol label switching network as a backbone network and subscriber network is established using Wibro or IP network. It is a network that can use broadband multimedia service anytime and anywhere without interruption safely. Therefore, broadband integrated network provides all the services such as wired / wireless communication, broadcasting, and internet in a single packet-based network regardless of service, and information is interworked with each other.

In particular, the IMS system of the broadband integrated network is a system that can provide a multimedia service such as audio, video, text, chatting by interworking a heterogeneous network using an IP-based packet network.

In the IMS system, there is a call session control function (CSCF) that handles calls. The call session control function is an infrastructure system that performs basic functions for session control based on SIP (Session Initiation Protocol). Depending on the role, the call session control function (Proxy-CSCF, P-CSCF), interrogation- It is divided into call session control function (Interrogate-CSCF, I-CSCF), and serving-call session control function (Serving-CSCF, S-CSCF).

The IMS system handles subscriber registration, authentication, billing, service-specific triggering and routing to the application server, caller location query, SIP message compression and decompression. In addition, there may be an HSS (Home Subscriber Server) storing subscriber profile information, authentication, and location related data, and an application server that provides a corresponding service with actual service logic.

Next, a call setup method in a conventional IMS system will be described with reference to FIG. 1.

1 is a flowchart illustrating a call setup method in a conventional IMS system.

Referring to FIG. 2, when a subscriber station A 10 in the conventional IMS system makes a call setup request to P-CSCF1 to connect to subscriber station B 20 belonging to another network (S1), P CSCF1 is delivered to I-CSCF1 via S-CSCF1 (S2). I-CSCF1 requests the location information of the called subscriber to the HSS in response to the request for request setting from the subscriber station A 10 (S4), receives the location information from the HSS (S5), and the subscriber station B 20 receives the location information. A call setup request is made to S-CSCF2 of a network to which the network belongs (S6). Then, the S-CSCF2 requests the call establishment to the P-CSCF2 (S7), and the call establishment request is transmitted to the subscriber station B (20) (S8), so that the subscriber station A (10) and the subscriber station B belonging to the other network are connected. 20 may be connected to each other.

Conventional session control methods include session establishment in consideration of bandwidth. However, in order to prevent overload of the broadband convergence network, a specific service session establishment is not limited or an application server is not considered. Therefore, when an overload occurs in the broadband integrated network, there is a problem that a serious situation may occur where the communication network is paralyzed in case of not providing various services including wired and wireless communication properly.

Accordingly, the present invention is to solve the above problems, the session control based on the transmission or reception IP in the call session control unit (CSCF) of the soft switch that controls the service session of the subscriber in the IMS system that provides the Internet-based broadband integrated network service It is to provide a function to prevent the overload of the network by limiting.

In order to solve the above technical problem, a session control system according to an embodiment of the present invention,

A session control server that generates and registers call blocking information for limiting session establishment when at least one of a transmission or reception IP is a restriction target IP when establishing a service session, based on the information of each of the transmission / reception IPs causing the network overload; And a soft switch for limiting a session establishment request of a subscriber station to a registered transmission / reception IP based on the call blocking information.

The apparatus may further include an application server providing one or more services, and the call blocking information may be configured to limit the session establishment rate according to a threshold for each service or service for limiting the number of session establishments per second for each service sharing the resources of the application server. Contains information.

On the other hand, the method of registering the call blocking information by the session control server of the session control system for preventing overload according to an embodiment of the present invention,

Registering session restriction information for each transmit / receive IP based on the information of each transmit / receive IP causing an overload in the network; And registering session restriction information for each service in consideration of a resource of an application server providing one or more services to a subscriber station.

The registering of session restriction information for each transmission / reception IP may include: a) designating a proxy-call session control unit (Proxy-CSCF) of a soft switch to register the session restriction information for transmission / reception IP; b) specifying whether an IP to control the session is a transmission or reception; c) setting the IP and subnet mask and specifying a call unit and an allowance to be blocked; And d) specifying the type of service to be restricted.

The registering of the session restriction information for each service may include: e) designating a serving-call session controller (Serving-CSCF) of a soft switch to register the session restriction information for each service; And f) setting an allowance for each service of the corresponding serving call session controller.

On the other hand, the method of controlling the session by the soft switch of the session control system for preventing overload according to an embodiment of the present invention,

a) receiving a call establishment request from a subscriber station and confirming whether the transmission / reception IP of the call establishment request is registered in call blocking information; b) if at least one of the transmission / reception IPs is information registered in call blocking information in step a), determining whether to allow by checking an allowance of the corresponding IP registered in the call blocking information; c) if the determination result of step b) is allowed, checking whether the threshold for the resource occupancy of the corresponding application server is exceeded when accepting the service requested by the subscriber station, and accepting the acceptance if not exceeded; And d) responding to the result of the call request to the corresponding subscriber station according to the result of the acceptance.

And, before the step a), the soft switch further comprises the step of receiving and registering the call blocking information from the outside.

By the above-described configuration, the soft switch according to the present invention can provide resources to subscribers by managing resources in the network based on call blocking information and preventing overload of the network and a system connected to the network.

In addition, by preventing overload of the network, it is expected to increase the profits and reduce the operating cost due to more efficient and stable operation of the network.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software. have.

Now, a session control method and system for preventing overload in an IMS scheme according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram illustrating a session control system for preventing overload in an IMS (IP Multimedia Subsystem) system according to an embodiment of the present invention.

Referring to FIG. 1, a session control system according to an exemplary embodiment of the present invention includes a call session control function (CSCF) 110, a media gateway control function (MGCF) 120, and a session. It includes a soft switch 100 including a control DB (130), a subscriber information management server (HSS) 200, an application server (AS) 300, and a session control server 400. .

When the soft switch 100 receives a session connection request from the subscriber station 10 to use the broadband integrated network service, the soft switch 100 performs the session of the subscriber station 10 according to the information and destination of the subscriber station 10 and the service to be used. It is a device to control. The soft switch 100 is not an actual device for switching, but processes various messages for managing call status while performing call control and arbitration functions. Accordingly, the subscriber station 10 requesting the session setup with the soft switch 100 may use a communication service such as voice oer internet protocol (VoIP), video conferencing, or a stream type service such as IPTV (Internet Protocol Television) with another subscriber station. Can be provided.

In particular, the soft switch 100 according to the present invention registers session restriction information for each transmission / reception IP and session restriction information for each service for limiting the number of session settings for each service, and is registered from the session control server 400. In the request for session establishment, the server allocates resources according to the registered information. Hereinafter, the session restriction information for each transmission / reception IP and session restriction information for each service are called call blocking information.

The call session controller (CSCF) 110 according to the configuration of the soft switch 100 controls the SIP (Session Initiation Protocol) -based multimedia session, proxy-call session controller (Proxy-CSCF) 111, interrogation- A call session controller (Interrogate-CSCF) 112 and a serving-call session controller (Serving-CSCF) 113.

The P-CSCF 111 serves as a gateway for the subscriber station 10 to access a specific service session for the first time, and performs the function of authenticating and allocating the resource of the subscriber station 10. The P-CSCF 111 has a session control information table having call blocking information synchronized with the session control server 400, and compares the session control information table whenever a service session establishment request is received from the subscriber station 10. By accepting or rejecting the session establishment according to the call blocking information, and sends a response to the subscriber station (10).

The I-CSCF 112 serves as a contact point for all incoming calls and a contact point with other network subscribers roaming in the network to connect to the subscriber station 10 in the network. In order to determine the location of the called subscriber according to the HSS 200 performs a function to route the call.

The S-CSCF 113 performs session management and session control of the session, and interworkes with the HSS 200 to receive and call a subscriber profile. In addition, it performs all functions related to providing a service such as interworking with the application server 300 and providing service related information.

The S-CSCF 113 according to the present invention checks the resources of the application server 300 when a call setup request is made by the subscriber station 10 and determines whether or not the resource threshold is exceeded according to service acceptance for each resource. You can accept or decline. In this case, the S-CSCF 113 has a function of limiting the number of session settings for each service of the application server 300 or limiting the ratio according to the session limit information for each service registered from the session control server 400.

The media gateway control function (MGCF) 120 performs a media gateway control function for interworking an existing network such as an all-IP network and a public telephone network.

The session control DB 130 stores session restriction information for each IP and session restriction information for each service for the session control function of the P-CSCF 111.

The HSS 200 performs a function of registering subscribers and various authentication functions necessary for initial registration, and interworking with application servers to provide various multimedia services and routing a call based on triggering information. To perform.

The application server 300 is a server for providing various services in conjunction with the soft switch 100 and is a server for providing various application services according to a standardized interface. In addition, the application server 300 may include a media server (not shown), and the media server may provide a multimedia service to a user using various multimedia contents to provide a multimedia service.

The session control server 400 generates session restriction information for each transmission / reception IP with respect to the transmission / reception IP causing an overload of the specific P-CSCF 111 in the network, and the service control session connected to the specific S-CSCF 113. Create and provide session limit information for each service that limits the number for each service.

Next, the session control server 400 according to an embodiment of the present invention will be described with reference to FIG. 3.

3 is a block diagram schematically illustrating a session control server according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the session control server 400 according to an embodiment of the present invention includes a session information collecting unit 410, a session limit setting unit 420, a GUI providing unit 430, and a session control synchronization unit ( 440, a control unit 450, a communication unit 460, and a session control management DB 470.

The session information collecting unit 410 collects information about resources of the application server 300 for providing a service and provides the session limit setting unit 420. The resources are CPU, memory, and service channel of each application server 300, and the utilization rate and load rate threshold for each resource for each resource may be previously designated by the NMS operator or collected from the application server 300.

For example, the NMS periodically monitors information on call volume of each service. And N 1 services S ₁ , S ₂ ,... , Assume that S _N is provided while sharing the application server 300 which is the same resource. In this case, when each service is called once, the relative weights occupying CPU (A), memory (B), and service channel (C) which are resources of the application server 300 are respectively (A ₁ , A ₂ ,... , A _N ), (B ₁ , B ₂ ,…, B _N ), (C ₁ , C ₂ ,…, C _N ). Then, the services S ₁ , S ₂ ,..., Which share the application server 300. , S _N is the average m ₁ , m ₂ ,... We can see that m is called at the rate of _N times (assumed 1).

The session limit setting unit 420 registers a transmitting or receiving IP causing an abnormal traffic to the network and causing an overload to set call blocking information for the registered IP. Herein, the IP registered in the call blocking information is a corresponding application server when traffic congestion occurs in a server equipment such as a subscriber terminal IP or an application server 300 by a network operator or a report of a transmitting or receiving terminal subscriber. 300) may be IP information.

In addition, the session limit setting unit 420 has a function of registering and limiting the number of session settings for each service of the application server 300 and registering a ratio. The two methods will be described below.

For example, the session limit setting unit 420 may have a value L _A in which the utilization rate of the resource CPU A of the application server 300 reaches 100% in the description (assumed 1) of the session information collecting unit 410. Can be obtained as L _A * (A ₁ * m ₁ + A ₂ * m ₂ +… + A _N * m _N ). In the same manner, L _B and L _C , which are values at which the utilization rates of the memory B and the service channel C reach 100%, can also be obtained.

The session limit setting unit 420 may set the threshold of each service by taking the smallest value among the L _A , L _B , and L _C. That is, if the above calculation result thresholds are L _A = 100, L _B = 120, and L _B = 110, the S ₁ service of the application server 300 is called 100 * m ₁ times per second to set the number of session settings. Can be set. Here, the set threshold may be expressed as an allowance as a value used as a reference for allowing or rejecting a call setup request.

On the other hand, the session limit setting unit 420, in consideration of the service priority to prevent the low-grade service to provide more than the specified threshold or set a relatively low tolerance, and for the high-grade service load rate of the application server 300 By viewing and determining, session limit information for each service may be set.

For example, the session limit setting unit 420 may be used for each CPU (A), memory (B), and service channel (C) which are resources according to the application server 300 in the description of the session information collecting unit 410 (assumed 1). You can manage the load rate for service calls.

That is, m ₁ , m ₂ ,... , m _n times, the current load factor is A ₁ * m ₁ + A ₂ * m ₂ +. + A _N * m _N. At this time, if the S ₁ service is called once more, A ₁ * (m ₁ +1) + A ₂ * m ₂ +. It is determined whether or not the service is accepted by determining whether A _N * m _N exceeds a threshold of the specified resource CPU (A). In this case, the allowable ratio set according to the threshold may be set as a default of 70% to 80% of the stability threshold of the system, it can be set by specifying the value by the NMS operator.

The GUI providing unit 430 provides a GUI to the NMS to allow session control settings from the NMS operator. At this time, the operator of the NMS registers or deletes session restriction information for each transmission / reception IP that causes an overload through the management screen as shown in FIG. 4. In addition, when a session-specific session restriction information registration command is issued to a specific P-CSCF 111 through the management screen as shown in FIG. 5, the session control server 400 sends session-specific session restriction information to the corresponding P-CSCF 111. Create it and get it.

In this case, the call blocking information including the session restriction information for each transmission / reception IP and the session restriction information for each service may be configured in the form of a session control information table as shown in FIG. 6. The session control information table includes at least one of IP, subnet mask, transmission / reception, service, control method, allowance (threshold), current attempt call session number, total attempt call range, and last call setup allowance time of a subscriber station. Include.

The session control synchronizer 440 registers the session restriction information for each transmission / reception IP and the session restriction information for each service generated by the session restriction setting unit 420 to each soft switch 100 to synchronize.

The control unit 450 has a function of controlling the overall operation of the components in the session control server 400, the communication unit 460 transmits a GUI to the NMS, or various registration information according to the GUI settings of the NMS operator On the other hand, the communication for interworking with the soft switch 100 is performed.

The session control management DB 470 stores session limit information for each transmission / reception IP, session limit information for each service, and service usage rate and load rate threshold for each resource of the application server 300 generated by the session limit setting unit 420.

Hereinafter, a session control method of a session control system according to an exemplary embodiment of the present invention will be described in detail with reference to the flowcharts illustrated in FIGS. 7 to 12.

The session control system according to the present invention controls the session for the abnormal transmission and reception IP in order to minimize the occurrence of abnormal traffic in the network and to prevent overloading of related systems such as the soft switch 100 and the application server 300.

Meanwhile, a method in which the session control server 400 registers session restriction information for each transmission / reception IP to the soft switch 100 will be described with reference to FIG. 7.

7 is a flowchart illustrating a session restriction registration method for each transmission / reception IP according to an embodiment of the present invention.

Referring to FIG. 7, the session control server 400 according to an embodiment of the present invention provides a GUI to the NMS. Then, in order to block registration of the abnormal transmission / reception IP according to the operator's setting through the GUI, the P-CSCF 111 of the corresponding soft switch 100 is set (S701), and whether the IP to control the session is transmission or reception. (S702). Then, the IP to be blocked and the subnet mask (subnet mask) is set (S703), and the call unit and the allowance to be blocked are specified (S704).

Here, the unit of the call to be blocked may be specified as a percentage (%) or a time (Time), and if the unit is a percentage (%), the allowance (threshold) is allowed as much as a percentage (%) corresponding to the allowance of all call setup requests. . For example, if the unit is a percentage and the allowance is 30, only 30% of all call setup requests can allow call setup. On the other hand, if the unit is seconds, only one number per second corresponding to the allowable value is allowed. That is, if the unit is second and the allowance is 30, only one call setup request can be allowed per 30 seconds. Then, the call type of the service to be blocked is set (S705), and the corresponding information is registered in the P-CSCF 111 of the soft switch 100 (S706).

Meanwhile, a method in which the session control server 400 registers session restriction information for each service in the soft switch 100 will be described with reference to FIG. 8.

8 is a flowchart illustrating a method of registering session session restriction information for each service according to an exemplary embodiment of the present invention.

Referring to FIG. 8, the session control server 400 according to an embodiment of the present invention designates an S-CSCF 113 to adjust the number of sessions (S801), and the current service in the corresponding S-CSCF 113. The number of limited sessions per star is checked (S802). Then, the number of sessions for each service is changed to generate session restriction information for each service (S803), and the generated session restriction information for each service is registered in the S-CSCF 113 (S804).

As described above, the session control server 400 according to the present invention registers the session restriction information for each transmission / reception IP and the session restriction information for each service in the soft switch 100 to the session control of the soft switch 100. Depending on the role, there is a characteristic to reduce the overload in the network.

Meanwhile, the call of the subscriber station 10 is performed by the soft switch 100 according to the embodiment of the present invention through FIG. 9 based on session restriction information for each transmission / reception IP and session restriction information for each service registered in FIGS. 7 and 8. Describes how to accept or reject a configuration request.

9 is a flowchart illustrating a method in which a soft switch controls a call setup request of a subscriber station according to an embodiment of the present invention.

Referring to FIG. 9, the P-CSCF 111 of the soft switch 100 according to an embodiment of the present invention receives a call establishment request from a subscriber (S901), checks the requested call information, and transmits and receives the corresponding call. It is checked whether the IP is registered in the call blocking information and whether the service of the call blocking information registered with the same IP as the service of the corresponding call is matched (S902). If it is registered, it checks the allowance in the call blocking information to check whether the corresponding call can be accepted (S903).

For example, if the session control method is a percentage (%) and the allowance is 30%, if the number of attempted calls (call setup request) is 99 and the number of allowed attempts (tolerance) is less than 30, the call request is rejected. On the other hand, if the number of allowed attempts is 30 or more, the call request is accepted. Similarly, if the session control method is sec, if the allowance is 30 seconds, the last call setup time is checked. If the session control method is set 30 seconds before the current time, the call setup is accepted. That is, if the call setup allowance cannot accept the current attempt call, the call setup is rejected (S913).

On the other hand, if the information of the call requested in step S902 is not registered in the call blocking information, or if the call setup allowance value can accept the current attempt call in step S903 (S904), the attempt call is put in the call setup processing queue. (S905). In this case, preferably, the call setting processing queue may use a queue using a leaky bucket algorithm to prevent the overflow of the queue.

Next, the call establishment checks whether the call establishment is successful according to the processing result in the call establishment queue (S906). If the call establishment succeeds, the number of current connection sessions for the corresponding service is increased by 1 (S907). Notify the request subscriber terminal 10 of the failure (S913).

By checking whether the call control method of the call blocking information registered in the P-CSCF 111 of the soft switch 100 is the number of times (S908), if the number of times, the session value currently set in the call blocking information is increased by 1 (S909). , The total number of attempts is also increased by one (S910). Alternatively, in step S908, if the control method is not the number of times, it is checked whether it is time (S911). If the registered control method is time, the last call setup allowable time is changed to the present time (S912).

Meanwhile, a method of controlling a call when the soft switch 100 requests a call release from the subscriber station 10 according to an embodiment of the present disclosure will be described with reference to FIG. 10.

10 is a flowchart illustrating a method in which a soft switch adjusts a call release request of a subscriber station according to an exemplary embodiment of the present invention.

Referring to FIG. 10, when the P-CSCF 111 of the soft switch 100 according to an embodiment of the present invention receives a call release request from a subscriber station (S1001), the transmission / reception IP of the requested call is call blocking information. In step S1002, if the service of the requested call matches the call blocking information (S1003), the session information setting value currently set in the call blocking information is reduced by one (S1004). The number of current connection sessions for the service is reduced (S1005), and the requested call release is executed (S1006).

If the transmission / reception IP of the call requested in step S1002 is not registered in the call blocking information, or if the service of the call requested in step S1003 does not match the call blocking information, the process proceeds to step S1005.

Meanwhile, a method of controlling the session according to the resource occupancy setting for the application server 300 by the soft switch 100 according to the embodiment of the present invention will be described with reference to FIG. 11.

11 is a flowchart illustrating a method in which a soft switch performs session control according to resource occupancy setting for an application server according to an embodiment of the present invention.

Referring to FIG. 11, when the soft switch 100 according to an embodiment of the present invention receives a service call setup request from the subscriber station 10 (S1101), the soft switch 100 applies the corresponding service when accepting the requested service. It is checked whether the threshold for the CPU among the resources of the server 300 is exceeded (S1102). In addition, depending on whether the threshold of the CPU is exceeded (S1103), if it is not exceeded, it is checked whether the threshold for the memory among the resources of the application server 300 is exceeded (S1104). In addition, depending on whether the threshold of the memory is exceeded (S1105), if not exceeded, it is checked whether the threshold for the service channel among the resources of the application server 300 is exceeded (S1106). Then, depending on whether the service channel threshold is exceeded (S1107), if not exceeded, the requested call establishment request is accepted (S1108), and the corresponding number of service attempts is increased by 1 (S1109).

On the other hand, the soft switch 100 is S1102, S1104. If the thresholds for the CPU, memory, and service channel are exceeded in step S1106, the call establishment request is rejected (S1110).

Next, the soft switch 100 according to the embodiment of the present invention through FIG. 12 is S1102 and S1104 of FIG. A method of determining whether a threshold is exceeded for a CPU, a memory, and a service channel is described in operation S1106.

12 is a flowchart illustrating a method of determining whether a soft switch exceeds a threshold of resource occupancy for an application server according to an exemplary embodiment of the present invention.

12, the soft switch 100 according to an embodiment of the present invention checks the share of the corresponding resources (CPU, memory, service channel) for each service of the application server 300 (S1201) Check the current number of calls of the service for each (S1202). The threshold value set for the corresponding resource is checked (S1203). Then, multiply the resource share and the number of calls for each service, and then add all the values to obtain the total share of the corresponding resource, and add the share of the corresponding resource to the service for which the setting request came from to set the requested service. The total occupancy rate for the corresponding resource is calculated (S1204). The total occupancy rate of the corresponding resource calculated in the step S1205 and the threshold of the corresponding resource are compared to determine whether the threshold is exceeded (S1205).

As described above, the soft switch 100 according to the present invention manages resources based on call blocking information registered from the session control server 400 to prevent load of a corresponding network or a system connected to the network, thereby providing stable services to subscribers. There is a characteristic.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a flowchart illustrating a call setup method in a conventional IP Multimedia Subsystem (IMS) system.

2 is a diagram illustrating a session control system for preventing overload in an IMS scheme according to an exemplary embodiment of the present invention.

3 is a block diagram schematically illustrating a session control server according to an exemplary embodiment of the present invention.

4 is a structural diagram illustrating a management screen for registering session restriction information for each transmission / reception IP according to an embodiment of the present invention.

5 is a structural diagram illustrating a management screen for registering session restriction information for each service according to an exemplary embodiment of the present invention.

6 is a structural diagram showing a session control information table according to an embodiment of the present invention.

7 is a flowchart illustrating a method of registering session restriction information for each transmission / reception IP according to an embodiment of the present invention.

8 is a flowchart illustrating a method of registering session session restriction information for each service according to an exemplary embodiment of the present invention.

9 is a flowchart illustrating a method in which a soft switch controls a call setup request of a subscriber station according to an embodiment of the present invention.

10 is a flowchart illustrating a method in which a soft switch adjusts a call release request of a subscriber station according to an exemplary embodiment of the present invention.

11 is a flowchart illustrating a method in which a soft switch performs session control according to resource occupancy setting for an application server according to an embodiment of the present invention.

12 is a flowchart illustrating a method of determining whether a soft switch exceeds a threshold of resource occupancy for an application server according to an exemplary embodiment of the present invention.

Claims (16)

A session control server that generates and registers call blocking information for limiting session establishment when at least one of a transmission or reception IP is a restriction target IP when establishing a service session, based on the information of each of the transmission / reception IPs causing the network overload; And Soft switch for limiting session establishment request of subscriber station for registered transmission / reception IP based on the call blocking information Session control system comprising a. The method of claim 1, It further includes an application server that provides one or more services, The call blocking information is session control system including information for limiting the number of session settings per second for each service sharing the resources of the application server. The method of claim 1, It further includes an application server that provides one or more services, The call blocking information includes session limiting information for limiting a session establishment rate according to a threshold for each service sharing a resource of an application server. The method of claim 2 or 3, And the resource of the application server includes one or more of a CPU, a memory, and a service channel. The method of claim 4, wherein The call blocking information, Session control system comprising one or more of the subscriber station's IP, subnet mask, transmission / reception, service type, control method, allowance, number of current attempted call sessions, total attempted call range, and last call setup allowed time. The method of claim 5, wherein The soft switch, And a call session control function (Call Session Control Function) for limiting or limiting the number of sessions for each service of the application server according to the call blocking information. The method of claim 6, The call session controller, When the call establishment request, the session control system characterized in that the call setting is limited by determining whether or not the resource threshold value according to the service acceptance for each resource of the application server. In the session control server of the session control system for preventing overload to register call blocking information, Registering session restriction information for each transmit / receive IP based on the information of each transmit / receive IP causing an overload in the network; And Registering session limit information for each service considering resource of an application server providing one or more services to a subscriber station; Call blocking information registration method comprising a. The method of claim 8, Registering session restriction information for each transmission / reception IP, a) designating a proxy-call session control unit (Proxy-CSCF) of a soft switch to register the session restriction information for each transmit / receive IP; b) specifying whether an IP to control the session is a transmission or reception; c) setting the IP and subnet mask and specifying a call unit and an allowance to be blocked; And d) specifying the types of services to be restricted Call blocking information registration method comprising a. The method of claim 9, Registering the session restriction information for each service, e) designating a serving-call session controller (Serving-CSCF) of a soft switch to register the session restriction information for each service; And f) setting an allowance for each service of the corresponding serving call session controller; Call blocking information registration method comprising a. The method of claim 10, The allowance is If the call unit is a time (Time) for each service, only one call per set time corresponding to the allowable value, or if the call unit is a rate is registered to allow only when the rate according to the request service acceptance does not exceed the allowable value How to register call blocking information. In the method of controlling the session by the soft switch of the session control system for preventing overload, a) receiving a call establishment request from a subscriber station and confirming whether the transmission / reception IP of the call establishment request is registered in call blocking information; b) if at least one of the transmission / reception IPs is information registered in call blocking information in step a), determining whether to allow by checking an allowance of the corresponding IP registered in the call blocking information; c) if the determination result of step b) is allowed, checking whether the threshold for the resource occupancy of the corresponding application server is exceeded when accepting the service requested by the subscriber station, and accepting the acceptance if not exceeded; And d) responding to the result of the call request to the corresponding subscriber station according to the result of the acceptance; Session control method comprising a. The method of claim 12, Before step a), And receiving, by the soft switch, call blocking information from the outside and registering the call blocking information from the outside. The method according to claim 12 or 13, B), And if the current number of attempted call sessions is less than the allowable ratio, when the allowable unit of the call blocking information is a ratio (%). The method of claim 14, And if the call request is allowed, increase the ratio of the current number of attempted call sessions of the call blocking information. The method according to claim 12 or 13, The step b), if the allowance unit of the call blocking information is Time (Time), the session control method, characterized in that finally, if the call request time from the allow time exceeds the allowance.

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