KR960006469B1 - Overload control method in the intelligent network - Google Patents

Abstract

detecting whether an overload state begins by comparing the size of a service control point input buffer with its reference value according to the increase of call of an intelligent network; controlling the overload at the service control point during a delayed time until the call of the intelligent network is reduced under control of the overload at a service switching point from a time when the overload state is detected by the service control point during the initial overload state; assuming that the number of calls tried in the service switching point during the present control section at the service control point; regrading the assumed call as the number of calls of the intelligent network tried at the service control point; comparing the number of calls tried in the service control point with the process capability of the service control point in the current control section; checking whether the overload state is finished; if an overload control variable value produced at the service control point is transferred to the service switching point, regulating the call of the intelligent network by a subscriber's try, based on the control variable value at the service switching point; and repeating the above operations until the overload state is finished.

Description

Overload Control Method in Intelligent Network

1 is a hardware configuration to which the present invention is applied,

2 is a message flow diagram between SSP and SCP,

3 is the SCP hardware diagram,

4 is an SSP hardware diagram,

5 is an overall processing flow chart according to the present invention,

6 is an overload control flow diagram inside an SCP,

7 is a flowchart illustrating control variable value calculation in an internal processor of SCP.

* Explanation of symbols for main parts of the drawings

13: SCP internal processor 14,15: SCP internal input buffer

16: Total flow of information request message sent from SCP to SSP

17: flow of information request message allowed by SCP

18: Flow of information transmission request message rejected by SCP

19: flow of messages except SCP request message

20: SSP internal processor 21,22: SSP internal input buffer

23: total flow of intelligent network service request message attempted from subscriber to SSP

24: Flow of intelligent network service request message allowed in SSP

25: Flow of intelligent network service request message rejected by SSP

26: total flow of the aforementioned message from the SCP to the SSP

In the present invention, an intelligent network is referred to as one or a few centralized service control systems (Swervice Control Points, hereinafter referred to as "SCP") and a plurality of distributed service switching points (SSPs). It is about overload control method in intelligent network to protect SCP composed of) from overload.

Although only ordinary telephone calls are serviced in the existing telephone network, but the intelligent network provides various services, the traffic characteristics of the intelligent network are very different from those of the existing telephone network, and the intelligent network structure is distributed with one or a few centralized SCPs. Since it consists of multiple SSPs, the bottleneck of traffic is likely to occur in SCP, so it should be protected from overload in case of overload.

The overload control methods in the existing functional network apply some modified methods to the overload control methods in the telephone network or call gapping method by reading the contents of the previously prepared table. However, these methods are problematic in terms of quality of service, such as SCP dropping below the nominal procesing capacity when traffic fluctuations are very fluctuating, resulting in lower overall throughput or increased latency. have.

The present invention devised to solve the problems of the prior art, provides an efficient overload control method that can satisfy the service quality such as delay time while maintaining the normal processing capacity of the SCP when the SCP is overloaded in the intelligent network Its purpose is to.

In order to achieve the above object, the present invention provides an SSP for recognizing a service call requiring an intelligent network service among subscribers, requesting SCP for necessary control information, and completing the service desired by the user when the requested information arrives. In applying an overload control method in an intelligent network consisting of an SCP having a service control logic and a database system providing data information, and an SSP and a signal link between the SCP, the SCP detects when the SCP reaches an overload condition. A second step of calculating a control variable value to be applied to the next section by the SCP, a third step of sending the control message including the control variable value to the SCP, and an SSP based on the control variable value in the control message Is performed by a fourth step of performing a function of controlling an intelligent network call.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a hardware system to which the present invention is applied, 1 for an intelligent network, 2 for SCP, 3 for SSP, 4 for signal link between SSP and SCP, 5 for subscriber line between subscriber and SSP, and 6 for intelligent network service Represent each subscriber.

2 is a message flow diagram between SCP (2) and SSP (3), the SSP that receives the intelligent network service request (7) message from the subscriber sends the information transmission request message (8) to the SCP, the SCP receiving the message It finds the necessary information and transmits the information transmission response message 9 to the SSP side in the reverse direction. Upon receiving this message, the SSP retransmits the call start notification message 10 to the SCP after performing necessary processing by the subscriber using the information in the message. After the subscriber completes the call, the SSP sends the call termination notification message (11) to the SCP side, and after receiving the message, the SCP receives the call termination message (12) to the SSP side after completing the processing. do.

3 is a hardware diagram inside SCP (2), which is composed of a processor (13) for calculating an overload control variable value to be applied in the SSP and two input buffers (14, 15) located at the front of the processor. Buffers are a temporary store of messages waiting for the processor to process. The upper input buffer 14 is a buffer for storing the information transmission request messages 8 of FIG. 2 which is the first message of the message flow between the SSP and the SCP, and the flow of the information transmission request messages 8 transmitted from the SSP ( 16) is divided into the flow of messages (17) allowed by overload control and the flow of rejected messages (18) when SCP is overloaded, and the flow of rejected messages because all messages are allowed when SCP is not overloaded. 18 is not. When the information transmission request message (8), which is the first message transmitted from the SSP to the SCP during overload, is processed, the flow of the remaining messages (19), that is, call start notification (10) and call end notification (11), are rejected. Do not process. The input buffer 15 at the bottom is responsible for storing the remaining messages 10 and 11 that control the information transmission request message 8 among the messages transmitted from the SSP to the SCP side.

4 is a hardware configuration diagram inside the SSP (3) SSP consists of a processor 20 for determining the rejection and acceptance of the intelligent network and two input buffers (21, 22) located in front of the processor, these input buffers A temporary store of messages waiting for the processor to process. The upper input buffer 21 is a buffer for storing only the intelligent network service request message 7 requested by the subscriber, and the flow 23 of the intelligent network service request message 7 transmitted from the subscriber is controlled when the SCP is overloaded. Divided into the flow of messages 24 allowed by the flow and the flow of messages 25 rejected, there is no flow of messages 25 rejected since all messages are allowed when the SCP is not overloaded. When the SSP is allowed to request an intelligent network service request message (7), which is a message requested by the subscriber when the SCP is overloaded, the flow of messages 26 transmitted from the SCP to the SSP, i.e., information transmission response (9) and call termination (12) Does not dismiss. The input buffer 22 at the bottom is responsible for storing messages (9, 12) sent from the SCP to the SSP.

5 is an overall flow chart according to the present invention, in which the start of the overload control is started if the size of the SCP input buffer 14 is larger than the reference value of the input buffer, otherwise the overload control is not overloaded (31). In this case, SCP overload control is started (32), and SCP predicts the number of calls attempted to each SSP during the current control section of the control section with intervals of 10 seconds, sums them all together, and calculates the number of calls attempted to the SCP (33). Shall be. If the number of calls attempted by the SCP during the current control interval is greater than the SCP's processing capacity (34), then control should be performed in a direction that reduces the number of calls attempted by the SCP, and SCP calculates the value of the overload control variable for the next control interval. (35) this value is put in the control message and transmitted to all SSPs (36). Upon receiving the control message, the SSP uses the overload control variable value transmitted during the next control interval to allow or reject the intelligent network call attempted from the subscribers (37) to ensure that an appropriate load is placed on the SCP. When the control section ends (38), the SCP determines whether the overload condition persists by adding the number of information transmission request messages requested from the SSPs during the current control section, and calculates a new overload control variable value to be applied to the next control section. SSPs are sent to the SSP, and the SSP is repeatedly adjusted based on the value of this control variable. If the number of calls attempted by the SCP is less than SCP's capacity (35), the overload condition ends.

FIG. 6 is a flow diagram of SCP internal overload control. When the SCP receives 39 an information request message 8 from the SSPs, the size of the current input buffer 14 is compared with the reference value 40. If the size is smaller than the reference value, the received information transmission request message is stored (41) in the input buffer l4 to be processed by the SCP. If the size of the current input buffer 14 is larger than the reference value, the received information transmission request message is Dismissed (42). Internal SCP overload control is applied during the delay from the time SCP detects an overload condition to an overload control on the SSP and the call is reduced.

7 is a flowchart of calculating a control variable value to be applied to the next control section by an internal processor of the SCP. The control variable value is calculated at the end of a control section having an interval of 10 seconds, and the SCP can process the control section. Since the total number of intelligent networks is multiplied by the processing capacity of the SCP per unit time and the length of the control section, the number of information transmission request messages (8) arriving at the SCP during the next control section is the total number of intelligent networks that the SCP can handle during the control section. Calculate the value of the control variable to approximate the number. That is, the value of the control variable is divided by the value of the control variable applied to the current control section and the total number of information transmission request messages (8) that will arrive at the SCP during the current control section by the product of the SCP processing capability per unit time and the length of the control section. (43).

Therefore, the present invention as described above has the effect of satisfying the service quality such as delay time and at the same time to maintain the normal processing capacity of SCP when SCP is overloaded in the intelligent network, it is possible to stably operate the intelligent network during intelligent network operation In addition, there is an effect that can improve the yield of the intelligent network.

Claims (3)

A ground network system having a Service Control Point (SCP) (2), multiple distributed Service Switching Points (SSPs) (3), and a signaling link (4) between the SSP and the SCP. An overload control method applied to a network, the first step of detecting whether an overload condition is started by increasing the traffic of an intelligent network call and comparing the size of the SCP input buffer with a reference value; During the initial overload condition, a second step in which the overload control is performed in the SCP during the delay time from the time the SCP detects the overload condition to the overload control in the SSP until the intelligent network call is reduced; The SCP predicts the number of calls attempted to each SSP during the current control interval, adds up all of them to the number of intelligent network calls attempted on the SCP, and compares the number of calls attempted to the SCP during the current control interval with the SCP throughput to determine if the overload is over. Third step of diagnosis; A fourth step of adjusting the intelligent network call attempted from the subscriber based on the control variable value, when the SCP calculates the value of the overload control variable and transmits the value to the SSP in a control message; A fifth step of repeating until the overload condition ends; Overload control method in an intelligent network comprising a. The method of claim 1, wherein the second step comprises: checking whether the size of the SCP input buffer is smaller than a reference value when receiving an information transmission request message; And storing the information transmission request message input buffer when the value is smaller than the reference value, and ending and rejecting the information transmission request message. The method as claimed in claim 1, wherein the fifth step includes a control variable value to be applied to the next control section to the SCP internal processor by multiplying the control variable value applied to the current control section by the total number of calls arriving at the SCP during the current control section. An overload control method in an intelligent network, characterized in that it is calculated by dividing the SCP processing capacity per hour by the length of the control section.