KR20010088168A - Method for stabilizing state of own station in congestion of No.7 network element - Google Patents

Abstract

PURPOSE: A method for maintaining the stability of a switch when an No.7 network element is converged is provided to maintain the stability of the switch by preventing an overload of the switch when sensing a CCS(Common Channel Signaling) No.7 network convergence. CONSTITUTION: A No.7 management unit of an MSC(Mobile Switching Center) receives a signaling terminal(ST) fault message, checks the number of total fault ST, and temporarily stops a management function of a corresponding ST to prevent a convergence when it is an ST convergence state(ST1-ST10). If it is judged as an STP(Signal Transfer Point) convergence state as a result of the check of the number of the total fault ST, or if it is judged as the STP convergence state after receiving an STP fault message, the No.7 management unit stops the state management of all STs through STPs during a uniform time to prevent the convergence(ST21-ST27). If a corresponding SSHP(Signaling System Handling Processor) is the convergence state after the No.7 management unit receives an SSHP fault message, the No.7 management unit instructs that the user message is deleted during a uniform time to the SSHP to prevent the convergence(S31-S36). If a corresponding ST is the convergence state after the No.7 management unit receives an ST fault message, the No.7 management unit instructs that the user message transmitted using STs is deleted during the uniform time to the SSHP to prevent the convergence(ST41-ST46).

Description

No.7 Method for stabilizing state of own station in congestion of No. 7 network element

The present invention relates to a method for stabilizing an exchange in a No.7 common line signaling network. In particular, the Mobile Switching Center (MSC) can detect congestion of the Common Channel Signaling (CCS) No.7 network. The present invention relates to a method for maintaining exchange stabilization during congestion of No.7 network elements that prohibits the automatic management of the signal point when it detects a continuous congestion of a specific signal point or to isolate the local exchange.

The contents of the No.7 common line signaling method are related to various methods for stably maintaining the signal network and ensuring the perfect transmission of the signaling message. In order to fulfill the unique purpose of No. 7, the actual international standard, ITU-T 7XX series, presents the standardized contents. However, each system that implements and uses No.7 signaling method has different hardware structure and software control method, and defines its own unexpected situation such as network congestion and system overload. Hard to do

1 is a block diagram of a No.7 network signal point for tracking the process of transmitting a No.7 message. The MSC 20 performs a mobile call exchange function, and the STP (Signal Transfer Point) 1 and the STP 2 40 are redundant structures for routing No. 7 signal messages. do. Home Location Register (HLR) A (50) and HLR B (60) register subscriber location to ensure mobility of mobile subscriber, respectively, and Service Control Point (SCP) 80 is intelligent network It has a function to adjust the service type, command, parameter, etc. related to the intelligent network to support the service. And the VMS (Voice Mail Service) 90 functions to record and transmit a message when the subscriber cannot answer the call.

In these No.7 network elements, No.7 messages are sent between the MSC and the MSC, between the MSC and the Home Location Register (HLR), between the MSC and the Service Control Point (SCP), and between the MSC and the VMS (Voice Mail). Service (voicemail equipment). The message transmitted here is information such as subscriber information for establishing a call of a mobile subscriber and the status of each No. 7 signaling point.

Fig. 2 is a block diagram of a hardware block for performing function No.7 for transmitting the message No.7.

No.7 messages are largely divided into two types of messages. No.7 call processing messages used by the user for call processing, and No.7 management messages used by each No.7 nodes to process each other's status, which are transmitted to each node . The No. 7 user unit 21 generates a call processing message, and the No. 7 management unit 22 generates a No. 7 management message. The call processing message and the No. 7 management message of the No. 7 user unit 21 generated as described above are connected to a destination signal point through a No. 7 message processor (SSDP) 23 in charge of message transmission. It goes through ST (Signaling Terminal) 24, 25. It is then sent to the desired station signal point (DP Y; HLR, MSC X, SCP, VMS, etc.) via the STP (signal relay station) 30, 40 dedicated to message routing in the middle of each signal point.

Fig. 3 is a structural diagram of layers of No. 7 protocol.

ISUP (ISDN User Part) message transmits message through MTP (Message Transfer Part) without using SCCP (Signaling Connection Control Point), and No. 7 User is loaded in each ASP and LRP. MAP processing block.

This No.7 User message is transmitted to the signal terminals (ST) 24 and 25 performing the MTP level 2 function by the message routing unit in the SSHP 23 performing the MTP level 3 function. In 24 and 25, when a message transmission request is received, the message is transmitted to a large power station through an actual physical path.

The message processor SSHP 23 in which the message processing is actually performed performs the MTP level 3 function, and the ST 24 and 25 perform the MTP level 2 function.

4A illustrates an initial management operation of the MSC when network congestion occurs due to a management message. When the signal point DP_Y becomes inaccessible, the process of the MSC 20 is shown. First let's say DP_Y is inaccessible. At this time, STP 1 (30) and STP 2 (40), which detects this fact, transmits a message prohibition message called TFP (Transfer Prohibited) to local exchange (MSC) 20. The MSC 20 then updates the internal database indicating the state of the power (DP Y) and sends a TFP message to the directly connected signal point such as DP X (10).

4B shows the periodic management operation of the MSC 20 after this initial management procedure is over. This is a method for keeping the information of the corresponding signal point always up-to-date. Each signal point (DP X) 10 is the STP (30) to indicate the state of the power signal point (DP Y) that is not available for processing. (40). That is, the DP X 10 periodically transmits a loop state test message (RST; Route State Test) to the STP 1 (30) and the STP 2 (40) to inquire the state of the signal point.

This procedure is essential for the state management of signaling points. However, the problem is that in a short time this procedure occurs numerous times or repeatedly.

4A and 4B show a situation that occurs when a change occurs in the state of one signal point DP Y, and FIG. 4C shows a plurality of signal points DP Y1, DP Y2, DP Y3, ..., DP Y102) shows a situation that occurs when a change occurs in the state of the STP (30, 40) at this time the situation is different.

Let's consider a case where two STPs (STP 1 (30) and STP 2 (40)) cause a momentary failure at the same time. The MSC 20 and each DP_Yxxx of the large stations are connected through the STP. In general, the paths to the signal points are shared by the STP 1 (30) and the STP 2 (40). In this case, therefore, a total of 204 paths exist between the MSC 20 and the local signal point DP_Yxxx. At this time, if a failure occurs in STP 1 (30) and STP 2 (40), the load of the MSC (20) is increased. The MSC 20 first performs a procedure of updating an internal database for a total of 206 ((204 + 2) STP) paths. In addition, the procedure of transmitting the unavailable information of the 104 signal points, that is, 104 TFPs to the DP X 10 is performed, and at this time, the load inside the MSC 20 suddenly surges.

If this situation is repeated continuously in a short time, the MSC has a significant load and the MSC has a problem of paralyzing due to the overload of the No.7 message processing function. In addition, there was a problem that the mobile communication service was interrupted because the call setup of the mobile subscriber was impossible during the MSC paralysis.

Therefore, the present invention has been proposed to solve the conventional problems as described above, the object of the present invention is

When Mobile Switching Center (MSC) detects common channel signaling (CCS) No.7 network congestion, it is prohibited to automatically manage the network element if No.7 network element continues to be congested. Or to maintain the exchanger stabilization in the event of runaway network element no.

In order to achieve the above object, the method of maintaining the exchanger stabilization during runaway network element No. 7 according to the present invention,

Receiving a signal point failure message from the No. 7 management unit of the switching center and checking the total number of fault signal points to determine that the signal point is congested, the first step of suspending the management function of the corresponding signal point to prevent congestion;

If it is determined that the STP failure state by checking the total number of failure signal points or if the No.7 management unit receives the STP failure message and determines that the STP is congested, the state management of all signal points passing through the STP is stopped for a predetermined time. A second step of preventing runaway;

Receiving a SSHP failure message from the management unit No. 7 and instructing the SSHP to discard the user message for a predetermined time when it is determined that the corresponding SSHP is congested;

If the No.7 management unit receives the ST failure message and determines that the ST is congested, the fourth step of preventing the congestion by instructing the SSHP to discard the user message transmitted using the ST for a predetermined time. It is characterized by the methodological configuration.

1 is a schematic diagram of No. 7 network;

2 is a block diagram of a hardware block for performing No. 7 functions;

3 is a structural diagram of each layer of the No. 7 protocol;

4A is a diagram illustrating an initial management operation of an MSC when network congestion occurs due to a management message;

4B is a view showing a periodic management operation of the MSC after an initial management procedure when no.7 network congestion occurs;

Figure 4c is a diagram showing a signal point management method of the MSC when a plurality of STP failure occurs,

5 is a view showing a method of maintaining the exchanger stabilization when the No.7 network element congestion according to the present invention.

<Explanation of symbols for the main parts of the drawings>

20: MSC 21: No.7 user part

22: No.7 management unit 23: SSHP

24,25: ST 30,40: STP

Hereinafter, the method of maintaining the exchanger stabilization when the No.7 network element congestion according to the present invention as described above in detail based on the accompanying drawings as follows.

In the present invention, the case of causing the failure of the MSC 20 due to the congestion of No.7 message processing can be divided into four cases, which will be described with reference to FIG.

First, in case of an overload occurrence of No. 7 management unit 22 due to occurrence of a failure of a specific signal point and repetition of resolution, second, in case of failure of STP 1 (30) and STP 2 (40), No. 7 management unit 22 Third, in case of overload occurrence of SSHP 23 due to increase of user message, fourth, in case of runaway occurrence of ST 1 (24) and ST 2 (25) due to increase of user message Can be.

In the first case, when the congestion and congestion canceling states of the same signal point are repeated for a short time, excessive state processing and message processing are required, and thus the possibility of failure of the MSC 20 increases, in this case, the corresponding signal point management function. Suspend to prevent runaway.

In the second case, if the continuous failure of STP 1 (30) and STP 2 (40) occurs, the possibility of failure of the MSC (20) increases. In this case, all signal points passing through the corresponding STP (30) (40). Stop status management for some time.

In the third case, when the load of the SSHP 23 is measured and the congestion state is detected, the user message is discarded.

In the fourth case, the ST 1 (24) and ST 2 (25) transmit the runaway state to the No. 7 management unit 22 to discard the user message to the ST (24) (25).

FIG. 5 is a flowchart illustrating a method of maintaining the exchanger stabilization during the congestion of the network element No. 7 of the present invention.

As shown, No.7 management unit 22 of the MSC 20 receives the signal point failure message and checks the total number of failure signal points, and if it is determined that the signal point congestion state, the management function of the corresponding signal point is suspended. A first step of preventing runaway (ST1-ST10); All signal points passing through the STPs 30 and 40 when the total failure signal point is determined to be an STP failure state or the No. 7 management unit 22 receives an STP failure message and is determined to be an STP congestion state. A second step (ST21-ST27) of stopping state management of the state for a predetermined time to prevent congestion; A third step of preventing the congestion by instructing the SSHP 23 to discard the user message for a predetermined time when the No. 7 management unit 22 receives the SSHP failure message and determines that the SSHP 23 is congested; ST31-ST36); When the No. 7 management unit 22 receives the ST failure message and determines that the ST is in a runaway state, the SSHP 23 is disposed to discard the user message transmitted by using the ST 24 and 25 for a predetermined time. Command to perform a fourth step (ST41-ST46) to prevent congestion.

In the first step ST1-ST10, when the signal point failure message is received by the No. 7 management unit 22 of the MSC 20, the total number of failure signal points is counted to determine the counting value as a failure state. A first sub-step ST1-ST3 for checking whether or not the set number is equal to or greater than; If the counting value is not equal to or more than the set number, the second sub-step (ST4) determines that the signal point is in a runaway state and operates the signal point runaway start timer. -ST6); A third substep (ST7) of abandoning state management of the signal point and ignoring all messages related to the signal point during the signal point congestion start timer operation; After the congestion start timer has ended, check whether the congestion of the signal point has been continued for a specific time, and if so, proceed to the operation of the congestion start timer of the second sub-step ST4-ST6; The fourth sub-step ST8-ST10 of releasing the congestion state of the signal point is performed.

In the second step ST21-ST27, if it is determined that the STP failure state is determined by checking the total number of failure signal points, or when the No. 7 management unit 22 receives the STP failure message, it is determined whether the STP is continuously congested. Checking first sub-steps ST21 and ST22; A second sub-step ST23 configured to prohibit management of a signal point of a route via the STP when the continuous congestion is detected as a result of the continuous congestion test; Operate the STP congestion start timer to check whether the congestion of the STP has been continued for a specific time, and if so, proceed to the second sub-step ST23; otherwise, the step of releasing the state of the signal point related to the STP; Performs three substeps ST24-ST27.

The third step (ST31-ST36), the first sub-steps (ST31, ST32) for managing the state of the SSHP runaway state when receiving the SSHP failure message in the No. 7 management unit 22; Second sub-steps (ST33, ST34) of instructing the SSHP to reduce the load by discarding a user message after the SSHP run-time start timer is driven; The third sub-steps ST35 and ST36 transmit a command to stop the discarding of the user message after the SSHP congestion start timer ends.

The fourth step (ST41-ST46), the first sub-step (ST41, ST42) for managing the state of the ST in a runaway state, when the No. 7 management unit 22 receives the ST failure message; A second sub-step (ST43, ST44) of instructing the SSHP 23 to discard the user message transmitted using the ST during the ST run-time starter driving time after driving the ST run-time start timer; The third sub-steps ST45 and ST46 are performed to instruct the SSHP 23 to stop discarding the user message after the ST run-time timer ends.

Referring to the stabilization and maintenance method of the exchanger when the No.7 network element congestion according to the present invention as described above are as follows.

When the signal point failure message is received by the No. 7 management unit 22 of the MSC 20, the No. 7 management unit 22 counts the total number of the failure signal points (ST1, ST2). It is checked whether the counting value is equal to or greater than the set number for judging the fault condition, and as a result, if the counting value is equal to or greater than the set number, that is, 80% or more, the process proceeds to ST22 (ST3).

However, if the counting value is not more than the set number, it is checked whether the corresponding signal point continuously causes a failure (ST4). That is, if it is repeated by checking whether the fault is repeated within 2 to 3 seconds, the signal point is determined to be a runaway state and the signal point runaway start timers are operated (ST5, ST6).

During the signal point congestion start timer operation, the state management of the signal point is abandoned and all messages related to the signal point are ignored (ST7). When the congestion start timer is over, it is checked whether the congestion of the signal point lasts within 2 to 3 seconds (ST8 and ST9). If so, the process proceeds to the run time start operation step ST6, and if not, releases the runaway state of the signal point (ST10).

If the signal point is not available, STP 1 (30) and STP 2 (40) are inquired using the route status test message. At the end of this procedure, the congestion of the signal point is processed without affecting the MSC 20.

On the other hand, as a result of checking the total number of failure signal points in the ST3, if it is determined that the STP failure state or the STP failure message received by the No. 7 management unit 22, it is checked whether the continuous runaway of the STP ( ST21, ST22). Thus, if continuous congestion has occurred within 2 to 3 seconds, it is set to prohibit the management of the signal point of the route via the STP (ST23).

The STP congestion start timer is operated to confirm whether the congestion of the STP lasted within 2 to 3 seconds (ST24 and ST25). As a result, if the congestion lasted within 2 to 3 seconds, the process proceeds to ST23, and if not, the state of the signal point related to the STP is released (ST26, ST27).

If the SSHP 23 is overloaded due to an increase in the No. 7 user message and the No. 7 management message, the No. 7 management unit 22 is notified of the overload of the SSHP 23. Therefore, when the No. 7 management unit 22 receives the SSHP failure message, the state of the SSHP 23 is managed in a runaway state (ST31, ST32).

After the SSHP congestion start timer is driven, the SSHP 23 is instructed to reduce the load by discarding the user message (ST33 and ST34). After the SSHP congestion start timer ends, a command to stop discarding the user message is transmitted to the SSHP 23 (ST35 and ST36). In the case of the SSHP 23 congestion processing, since the SSHP 23 is located inside the MSC 20, the steps of ST9 and ST26 are not performed.

On the other hand, when the ST failure message is received by the No. 7 management unit 22 of the MSC 20, the state of the ST is managed in a runaway state (ST41, ST42). After the ST congestion start timer is driven, the SSHP 23 is instructed to discard the user message transmitted using the ST during the ST congestion start timer driving time (ST43, ST44).

After the ST congestion start timer ends, the command to stop discarding the user message is instructed to the SSHP 23 (ST45, ST46).

As described above, the present invention, when the mobile switching center (MSC) detects the congestion of the common channel signaling (Common Channel Signaling (CCS) No.7 network congestion No.7 network element continues to runaway It is effective to prohibit the management of the network elements automatically or to isolate the local exchange to prevent the overload of the exchange, and to prevent the functional paralysis caused by the overload of the exchange. have.

Claims (5)

A No. 7 signaling switching center comprising an ST performing an MTP level 2 function, an SSHP performing an MTP level 3 function, and a No. 7 management unit generating a No. 7 management message; In STP routing No.7 message, A first step of receiving a signal point failure message from the No. 7 management unit of the switching center and checking the total number of fault signal points to determine that the signal point is congested, thereby suspending the management function of the corresponding signal point to prevent congestion; If it is determined that the STP failure state by checking the total number of failure signal points or if the No.7 management unit receives the STP failure message and determines that the STP is congested, the state management of all signal points passing through the STP is stopped for a predetermined time. A second step of preventing runaway; Receiving a SSHP failure message from the management unit No. 7 and instructing the SSHP to discard the user message for a predetermined time when it is determined that the corresponding SSHP is congested; If the No.7 management unit receives the ST failure message and determines that the ST is congested, the fourth step of preventing the congestion by instructing the SSHP to discard the user message transmitted using the ST for a predetermined time. Method of maintaining the exchanger stabilization during No.7 network element runaway, characterized in that. The method of claim 1, wherein the first step, Receiving a signal point failure message at the No. 7 management unit of the exchange, counting the total number of failure signal points and checking whether the counting value is greater than or equal to a set number for determining the failure state; A second sub-step of determining whether the signal point is a runaway state and operating a signal point runaway start timer if the counting value is not more than the set number and if the corresponding signal point is repeated for a specific time; A third substep of abandoning state management of the signal point and ignoring all messages related to the signal point during the signal point congestion start timer operation; After the congestion start timer has ended, check whether the congestion of the signal point has continued for a specific time, and if so, proceed to the operation of the congestion start timer of the second sub-step; otherwise, the congestion state of the signal point And stabilizing the exchanger when the no.7 network element is congested. The method of claim 1, wherein the second step, A first substep of checking whether the STP is continuously congested when the total number of failure signal points is determined to be an STP failure state or when the No. 7 management unit receives an STP failure message; A second sub-step of setting a prohibition of managing a signal point of a route via the STP when the continuous congestion has been detected as a result of the continuous congestion test; A third substep of activating an STP congestion start timer to check whether the congestion of the STP has been continued for a specific time, and if so, proceeding to the second sub-step; Method of maintaining the exchanger stabilization during congestion of No.7 network element, characterized in that performing. The method of claim 1, wherein the third step, A first sub-step of managing the state of the SSHP as a congestion state when the No. 7 management unit receives the SSHP failure message; A second substep of instructing the SSHP to reduce a load by discarding a user message after running an SSHP run-time timer; And performing a third sub-step of transmitting, to the SSHP, a command to stop discarding a user message after the SSHP congestion start timer ends. The method of claim 1, wherein the fourth step, A first sub-step of managing the state of the ST as a runaway state when the No. 7 management unit receives the ST failure message; A second substep of instructing the SSHP to discard a user message transmitted using the ST during the ST run-time starter driving time after driving an ST run-time start timer; And performing a third substep of instructing the SSHP to stop discarding the user message after the ST congestion start timer ends.