JPH08214063A - Intelligent network load balancing method - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a load distribution method for distributing the load of service control points in an intelligent network. By distributing the load of SCP stations, a subscriber accesses an IN service request call. The purpose is to improve the serviceability at the time (speed of response or reduction of reject rate). [Construction] Call distribution information for deciding to which SCP a service request call of an intelligent network from a subscriber is to be routed is provided to a service switching point (SS
P), the call distribution information is downloaded from the SCP, and the SSP routes the service control request to the SCP determined according to the call distribution information when there is a service request call from the accommodated subscriber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load balancing method for balancing loads of service control points in an intelligent network.

When the load on the service control point in the intelligent network increases, the serviceability is deteriorated such that the service request from the subscriber is rejected. Therefore, the load can be distributed so that the service control point does not become overloaded. Needed.

[0003]

2. Description of the Related Art Intelligent network (IN:
Intelligent Network) is a system in which the network is hierarchized into a transmission layer and a high-performance layer, and the high-performance layer controls the transmission layer to provide flexibility for adding services. The transmission layer has a basic call connection function such as a simple connection between terminals, and also drives an exchange switch etc. according to an instruction from the high function layer.
Itching Point: It is called a service exchange point.
High-performance layer is a new service program (SLP: Serv
ice Logical Plogram: Service logic program)
It has a function to manage data and data, a function to drive a transmission layer and actually execute a service.
ntrol Point).

Conventionally, when a subscriber of an SSP station accesses an IN service request call in an intelligent network, a service control request is issued to an SCP station from a subordinate SSP station. If not stored in the SCP station, (1)
An inquiry is made between other SCP stations as to whether or not the corresponding service is stored, and a service control request is routed to the SCP station where the corresponding service is stored. (2) The IN service request call is rejected. Or (3) when an SSP station receives a message from the SCP station indicating that the service cannot be processed, the SSP station inquires of another SCP station whether the service is stored, and the service is stored. For example, a service control request is routed to an existing SCP station.

[0005]

Therefore, when there is a service control request from an SSP station under the control of an SCP station,
If the service is not stored in the SCP station, another S
It is necessary to perform extra processing such as routing to the CP station, resulting in a problem that the load on the SCP station increases. Further, even when the load on the SCP station is increasing, the request from the SSP station is made at any time,
As a result, problems occur such as a slow response to the subscriber's service request and rejection of the IN service request call.

The present invention has been made in view of the above problems, and by distributing the load of the SCP station, the serviceability (speed of response or rejection rate) when a subscriber accesses an IN service request call is considered. It is intended to improve

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a method for distributing the load of a service control point (SCP) in an intelligent network, the service of the intelligent network from a subscriber. The service switching point (SSP) is provided with call distribution information for determining to which SCP the request call is to be routed, and the call distribution information is downloaded from the SCP. There is provided a load balancing method for the intelligent network, which routes the service control request to the SCP determined according to the call distribution information.

In the above load balancing method, the SCP monitors its own load state, and when the load increases beyond a predetermined amount, a change request is issued to the SSP to reduce the service control request to the own SCP. Can be configured to do.

This change request can be a request for rewriting the call distribution information so as to limit the call volume of the service control request to the relevant SCP or perform routing to another SCP.

In addition, the SSP is provided with a service execution function capable of executing the corresponding service based on the service logic program downloaded from the SCP, and when the load of the SCP increases to a predetermined amount or more, according to the change request from the SCP. The SSP may execute the corresponding service.

Further, the SSP monitors the number of rejects for the service control request to the SCP, and when the number of rejects exceeds a predetermined amount, the SSP sends the information registered in the call distribution information or to another SCP. Based on the call distribution information rewritten by the inquiry
Limit of service control request to other SCP or other SCP
May be routed to.

Further, this load balancing method may be carried out uniformly for all services, or may be carried out for each specific service.

[0013]

When the subscriber of the SSP dials the IN service access number, the SSP retrieves the IN call distribution information and determines which SCP controls the corresponding service. After the determination, the SSP sends S to the corresponding SCP.
Send a message via TP. Upon receiving the message, the SCP controls the corresponding service and transmits the switching processing information to the SSP. This allows S
The SP subscriber will receive the requested service.

When a new service is added or enhanced by the SCE, the service logic program SLP is stored in the SCP. At that time, service type information (that is, IN call distribution information) is given to each SSP. ) Is downloaded. Alternatively, the latest IN call distribution information may be transmitted to the SSP station when the switching processing information is transmitted in response to the IN call control request from the SSP.

Further, the program S generated by SCE
IN if the LP is a service that can be processed by each SSP
When the call distribution information is downloaded, it is possible to reduce access to the SCP by processing the service within the SSP.

Further, each SCP and SSP has a process for controlling the congestion state, and when the congestion state increases beyond a certain threshold value, the congestion control process is executed.
In the SCP, when the processing of the entire system or a specific service exceeds a threshold value, a temporary change request for IN call distribution information is issued to the SSP to restrict access to the SCP. Alternatively, program SLP to SSP
Service control is temporarily delegated to the SSP by downloading to.

Alternatively, the SSP manages the IN call access request, the number of calls actually executed and the number of rejected calls, and if the number of rejected calls exceeds a certain threshold, the call to the SCP The load of the SCP is distributed by limiting the number of the calls and routing the overflowed calls to other SCPs.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the configuration of an intelligent network that carries out a load balancing method according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a subscriber terminal, and 2 is an SSP station that performs switching (exchange) processing. These are controlled by the central control unit 2-1 which controls the entire exchange, and the main storage unit 2-2 has a program section 2-3 and a data section 2-4.
It consists of. Reference numerals 3 and 4 also denote SSP stations, which are also equipped with a central control unit and a main memory, but are not shown.

The program section 2-3 of the SSP station 2 stores programs for performing various processes. In this example, a digit translation processing program that analyzes a dial number from a subscriber, an IN service control processing program that performs processing according to the dial number when it is an IN service request call, and the like are shown. Further, IN call distribution information can be provided in the data section 2-4. The IN call distribution information is information defining which SCP station an IN service request call is to be routed, and is downloaded from the SCP station as service type information. FIG. 4 shows an example of this IN call distribution information. As shown in the figure, the service type (for example, service a) is indexed, and the SCP station number that routes the service request call, the other SCP station number that the SCP station routes when congestion occurs, the threshold of the number of rejected calls, and the like are stored. It

Reference numerals 5 and 6 are STP (Signal Transfer Point) for relaying signals between SSP and SCP.
Is. Reference numerals 7, 8, and 9 denote SCP stations that perform service control processing in response to service control requests from SSP stations. Also, each SCP station has a central control unit (for example, 7-1).
And a main storage device (for example, 7-2). Further, 10 is an SCE (Service Creati
on Environment: Service generation environment) Indicates a device. Services (for example, program SLP-
a) is generated, and the generated program SLP-a is S
It is stored in the main memory of the CP station.

Now, in this intelligent network, the program SL generated by the SCE device 10
It is assumed that P-a is stored in the SCP station 7 and also stored in the SCP stations 8 and 9. Therefore, S
The CP stations 7, 8 and 9 can execute the service a, but normally, the SCP station 8 mainly executes the service a. Further, the IN call distribution information stored in the SSP station 2 is as shown in FIG. 4, and the number of the SCP station accessing the service a is “8”, SC
The number of the SCP station to be routed when the P station 8 is congested is set to "9".

The operation of the system under the above conditions is shown in FIG.
Will be described below. (1) The subscriber 1 of the SSP station 2 dials the IN service number. The IN service number is, for example, "0"
120-12345 ".

(2) The SSP station 2 performs numeric translation of the received dial number using a numeric translation processing program and identifies whether it is an IN service request call. in this case,
IN using "0120" in the dialed numbers as a key
Identify service request calls.

(3) When the identification result is IN service a, the IN service control processing program is started,
The IN call distribution information stored in the data section is indexed by the service a to obtain information on which SCP station should be accessed. In this example, as shown in FIG. 4, the SCP station 8 is written as the access SCP station in the IN call distribution information.

(4) The SSP station 2 makes a service control request to the SCP station 8 based on the information obtained in the above procedure (3).

(5) Further, a new service or service enhancement (service modification, specification change, etc.) is SCE.
The program SLP generated by the device 10 is SC
When stored in the P station, the SCP station downloads the service type information indicating the generated service content to each SSP station. Alternatively, triggered by an IN service control request from the SSP station, the latest IN call distribution information is sent to the SSP station as additional information. As a result, the IN call distribution information of the SSP station can always be updated with the latest contents.

(6) In order to balance the load on the SCP station, the service control for the IN service request call is SS
It is also possible to store the program SLP of the corresponding service in the SSP station itself so that it can be processed in the P station. In this case, as shown in FIG.
Service (eg program SLP-
When a) is stored in the SCP station, its service is SSP
The station determines whether it can be executed by referring to the service correspondence table. For example, the program SL at the SSP station
Although the service control for controlling Pa is stored, the process is not actually started, and consider the case where the service is realized by accessing the SCP station. In that case, the SCP station is provided with a flag that the program SLP-a can be processed by the SSP station.

On the SCE device 10, the program SLP-
The function of a is enhanced to generate the program SLP-a ', and the program SLP-a' is stored in the SCP station. Then, the SCP station checks the flag corresponding to the service a by indexing the service correspondence table. As a result, when it is found that the service control is also stored in the SSP station, the program SLP-a 'is downloaded to the SSP station. As a result, the SSP station can also execute the service concerned by performing processing within the SSP station.

(7) Each SCP station is provided with an overload control processing function for controlling the congestion state. That is, the SCP station periodically measures the usage rate of its own CC (Central Control Unit), and when the CC usage rate exceeds a certain level, the load of the SCP station increases and it is in an overloaded state. It is judged and the IN access request (service control request) from the SSP station is rejected. In this case, it is not always necessary to reject all calls, for example, by giving the SCP station priority data for subscribers,
It is also possible to perform processing such as rejecting only the request of a subscriber with a low priority that has made an IN access request.

(8) If the SCP station does not reduce its CC usage rate even if it performs the above-mentioned overload control, that is, if the overload condition is not resolved, the SCP station sends the S
A request for changing the IN call distribution information is issued to the SP station.

(9) If this change request is, for example, a routing request (routing destination = SCP station 9),
When an IN call access call originates, the SSP station 2 routes the service to the SCP station 9 instead of the previously accessed SCP station 8. The routing destination information is the IN of the SSP station 2.
It may be registered in the call distribution information in advance, or may be notified to the SSP station 2 as additional information at the time of a routing request from the SCP station.

(10) Further, the change request is the SS of the service.
In the case of requesting processing in the P station, the program SLP of the corresponding service is downloaded from the SCP station to the SSP station in order to entrust the service control performed by the SCP station to the SSP station, and then the IN service request call is made. SSP
The service will be executed under the control of the station.

(11) When the change request is a call volume restriction, the SSP station restricts the number of calls that access the SCP station. For example, a certain fixed time (eg 10 seconds)
The number of calls that access the SCP station 7 is limited to 100 calls, and more calls are processed in the SSP station 2 or routed to another SCP station 9,
The load of the CP station 7 is distributed.

(12) Although the above (7) to (11) are for performing routing processing for all services depending on the congestion state of the system, it is also possible to perform the congestion control for each service. In this case, a threshold is given to the number of service accesses per fixed time, and when the threshold is exceeded, congestion control is performed only for the corresponding service.

(13) In the SSP station as well, congestion control can be similarly performed. In this case, the SSP station manages the total call volume for accessing the SCP station, the call volume for which the service was executed, and the rejected call volume, and when the call is rejected over a predetermined threshold, access to the SCP station is performed. To limit.

(14) As a method of limiting access to this SCP station, there is a routing process. The routing destination inquires of the SCP station in the network whether or not the service can be executed. The IN call distribution information is rewritten based on the result. Alternatively, the routing control may be performed by previously registering the routing destination at the time of congestion in the IN call distribution information of the SSP station.

(15) When the call is rejected by exceeding the threshold value for access to the SCP station, (1
In the same way as 1), the congestion of the SCP station is alleviated by limiting the call volume per fixed time.

[0038]

As described above, according to the present invention,
When an SCP station is congested in the intelligent network, the service control of that station is changed to another S station.
By delegating to the CP station or SSP station, or limiting the call volume, the load of the SCP and station is dispersed and S
It is possible to reduce congestion at the CP station. Therefore, when the subscriber accesses the IN service, the rejection of the service due to the congestion of the SCP station can be reduced,
Serviceability can be improved.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an intelligent network using the load balancing method of the present invention.

FIG. 2 is a diagram for explaining the operation of the embodiment.

FIG. 3 is a diagram for explaining the operation of the embodiment.

FIG. 4 is a diagram showing an example of IN call distribution information in the embodiment.

[Explanation of symbols]

 1 Subscriber 2, 3, 4 SSP (Service Switching Point) Station 5, 6 STP (Signal Transfer Point) 7, 8, 9 SCP (Service Control Point) Station 2-1, 7-1 Central Control Unit 2-2, 7-2 Main storage device 2-3 Program part 2-4 Data part 10 SCE (service generation environment)

Claims (6)

[Claims] 1. A method for distributing the load of a service control point in an intelligent network, wherein call distribution information for determining to which service control point a service request call of an intelligent network from a subscriber is routed to a service switching point. In addition, the call distribution information is downloaded from the service control point, and when the service switching point receives a service request call from the subscriber that accommodates the service distribution point, the service control request is sent to the service control point determined according to the call distribution information. Load balancing method for intelligent networks that routes data. 2. A service control point monitors its own load condition, and when the load increases above a predetermined amount, a change request is issued to the service switching point to reduce the service control request to its own service control point. The load balancing method for the intelligent network according to claim 1, wherein 3. The load of the intelligent network according to claim 2, wherein the change request is a request for rewriting call distribution information so as to limit a call volume of a service control request to the service control point or perform routing to another service control point. Dispersion method. 4. The service exchanging point is provided with a service execution function capable of executing the corresponding service based on the service logic program downloaded from the service control point, and when the load on the service control point increases to a predetermined amount or more, The load balancing method for an intelligent network according to claim 1, wherein the service switching point executes the corresponding service in accordance with a change request from the service control point. 5. The service exchange point monitors the number of rejects for a service control request to the service control point, and when the number of rejects exceeds a predetermined amount, the service exchange point is registered in the call distribution information. 2. The call volume limitation of a service control request for the service control point or routing to another service control point is performed based on the stored information or call distribution information rewritten by an inquiry to the other service control point. Intelligent network load balancing method. 6. The intelligent network load balancing method according to claim 1, wherein the load balancing is performed for each specific service.