KR19980044533A - Percentage Control Method for Traffic Congestion Control in Asynchronous Transfer Mode Switching Systems - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

Percentage Control Method for Traffic Congestion Control in Asynchronous Transfer Mode Switching Systems

2. The technical problem to be solved by the invention

It is intended to provide a percentage control method used in the traffic congestion control method that restricts the acceptance of call service requests from subscribers when an overload is detected in order to free the asynchronous delivery mode switching system from overload and to optimize network performance. .

3. Summary of Solution to Invention

A call forwarding control function in the call connection control processor of an asynchronous transfer mode switching system is located at the front end of the call admission control function. A natural number of up to 100% is optimally distributed between the allowable calls within the allowance, and at any point after the start of the function, the allowable call is flexibly output according to the given call allowance.

4. Important uses of the invention

Used to control traffic congestion in asynchronous delivery mode switching system.

Description

Percentage Control Method for Traffic Congestion Control in Asynchronous Transfer Mode Switching Systems

The present invention provides a method for controlling traffic congestion that limits the acceptance of a call service request from a subscriber when an overload is detected in order to remove the asynchronous transfer mode (ATM) switching system from an overload state and to ensure optimization of network performance. It relates to a percentage control method used for.

Traffic congestion in an information communication network occurs when traffic exceeding the network design capacity is imposed on a specific element in the network, or when a network device fails or fails. If this condition is left without proper measures, it can be fatal to the system operation such as a significant decrease in system performance, even down the system during operation.

Such overload or congestion may be caused by natural disasters, failures of specific exchanges, or domino events resulting from concentrated call service requests to their exchanges, and reservation of popular programs and major events organized by broadcasting media. For example, call service demand may be concentrated at a specific time. If a call service request is congested for a certain calling party for any reason, a large number of calls are not assigned a signaling channel or the Call Admission Control (CAC) function is required to call the system beyond its design capacity. This can lead to congestion or to provide call services much less than the system's own design capacity, and in the worst case, the system can go down. When this situation is neglected, the impacts are exerted on the exchange as well as on the adjacent exchange, which in turn has a significant adverse effect on the entire network.

In the conventional public telephone (PSTN) network or narrow-band integrated information network (N-ISDN), a method of restricting call inflow to a specific called party in order to prevent system congestion and to reduce system load is a method of limiting a percentage and a call gap ( Call Gap) method was used. Percentage control method is to accept the call request according to the restriction class without any condition for the call request arriving at the system with congestion and overload due to the percentage by class according to the congestion situation, and the call gapping method is somewhat different between the methods. However, it is basically a method of accepting a predetermined number of call requests within a predetermined time interval by using a timer in the exchange.

The conventional percentage control method has 8 control classes in units of 12.5%, and the control class is manually determined according to the incidence rate of the call and the inflow of 1 to 8 calls according to the 1 to 8 classes given based on the eight views is shown. Allowed.

Therefore, the conventional percentage control algorithm is fixed in eight steps of 12.5% unit in assigning a limit, so the control class is already determined, and thus a more flexible control is fundamentally impossible. As a result, when congestion occurs, fine traffic congestion control cannot be expected, and there is a problem in that it is difficult to flexibly match with an automatic traffic control function that can be added.

In order to solve the above problems, the present invention provides a call connection located in front of a call admission control (CAC) function existing in a call and connection control processor (CCCP) of an asynchronous transfer mode (ATM) switching system. Depending on the call connection request situation, which is concentrated to a specific called number before translation for the number, the limiting (call tolerance) is 1 to 100% of natural number, and the interval between the allowed calls is optimally distributed within the tolerance. It is an object of the present invention to provide a percentage control method that allows a flexible call to be output flexibly according to a given call rate at any point after the start.

1 is a structural diagram of an asynchronous transfer mode (ATM) exchange system to which the present invention is applied;

2 is a conceptual diagram of an allow call determination process used in the present invention;

3 is a flow chart of a percentage control method in accordance with the present invention.

Explanation of symbols on the main parts of the drawings

11: ATM local switching subsystem

12: ATM Central Switching Subsystem

13 subscriber matching module 14 access switch network module

15 call connection control processor 16 relay line matching module

17: internal connection switch network module 18: operation maintenance processor

In order to achieve the above object, the present invention, in the percentage control method for traffic congestion control applied to the Asynchronous Transfer Mode (ATM) switching system, the message in the message waiting state after initializing the incoming call and allow call parameters A first step of determining the type of message when receiving; As a result of the determination in the first step, if the message is an end message, the call is terminated. If the call control request message is received, the call admission rate is initialized from the arrival call, and the percentage value of the progressive rate of incoming call attempts and allowed call numbers is obtained. A second step of comparing; As a result of the comparison in the second step, if the progressive percentage is less than or equal to the call acceptance rate, the incoming call and the allow call variable are increased, and the call admission message is transmitted to the call admission control function. Transmitting a call release request message to a call admission control function; And after the third step is performed, it is determined whether an incoming call variable has a predetermined value, and if the predetermined call does not reach a predetermined value, the message transitions to the message waiting state. After reinitializing, transitioning to the message waiting state.

Hereinafter, with reference to the accompanying drawings will be described an embodiment according to the present invention;

1 is a structural diagram of an ATM switching system to which the present invention is applied, in which 11 is an ATM local switching subsystem, 12 is an ATM central switching subsystem, 13 is a subscriber matching module, and 14 is an access switch network module. 15 denotes a call connection control processor, 16 a trunk line matching module, 17 an internal connection switch network module, and 18 an operational maintenance processor.

A network management block distributed and loaded to an operation maintenance processor (OMP) 18 and a call connection control processor (CCCP) 15 of an asynchronous transfer mode (ATM) switching system includes an external network operation center, a statistical block, And from the overload block or from the network management block, the congestion originating call number and the congestion class information and the like are provided or identified. In order to prevent or mitigate congestion, the call is controlled in the network according to the rate limit for the call requiring the call connection to the called party.

The present invention provides a mechanism for determining whether to attempt to enter an asynchronous transfer mode (ATM) switching network of an attempted call by comparing the given rate limit with the progressive rate of call attempts and allowed calls.

2 is a conceptual diagram of an allow call determination process used in the present invention.

The allowance decision formula of the present algorithm may be expressed as Equation 1 below.

[Equation 1]

In FIG. 2, the X axis 21 represents the number of call attempts of the incoming call, and the Y axis 22 represents the percentage value of the progressive ratio of the number of incoming calls and the allowed number of calls. FIG. 2 shows a 40% call acceptance example in which a call is requested (23) when the call rate is not exceeded by comparing the progressive rate formula as shown in [Equation 1] above. Indicates.

3 is a flowchart of a percentage control method according to the present invention.

This algorithm, which is triggered from the network management block, initializes both the incoming call and allowed call variables to 1 (31), waits for a message from the outside, and receives a message (32) to determine the type of message (33). ) If the message is an end message, the call is terminated. If the call control request message is terminated, the call admission rate is initialized (34), and a percentage value of the progressive ratio of incoming call attempts and allowed call numbers is obtained (35). Compare (36).

The comparison shows that if the progressive percentage is less than or equal to the call tolerance, the incoming and allowed call variables are incremented by one (37) and a call admission message is sent to the call admission control function (38). It increments only 1 (39) and transmits a call release request message to the call admission control function (40).

Thereafter, it is determined whether the incoming call variable is 100 (41). If the incoming call variable is not 100, the message transitions to the message waiting state 32. If the incoming call variable is 100, the incoming call and allowed call variables are initialized to 1 again (42). Transition to the standby state 32.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those skilled in the art to which the present invention pertains, and the above-described embodiments and accompanying It is not limited to the drawing.

As described above, the present invention can make the call limiting rate more flexible than the conventional method, and by distributing and outputting the maximum allowed call intervals, the system can be controlled by combining the call and bandwidth resources even when the congestion of the call request continues. It has the effect of preventing fatal damage including damage and maintaining the performance of the system at the maximum design capacity.

Claims (2)

A percentage control method for traffic congestion control applied to an asynchronous transfer mode (ATM) switching system, A first step of determining a type of message when receiving a message in a message waiting state after initializing an incoming call and a permission call variable; As a result of the determination in the first step, if the message is an end message, the call is terminated. If the call control request message is received, the call admission rate is initialized from the arrival call, and the percentage value of the progressive rate of incoming call attempts and allowed call numbers is obtained. A second step of comparing; As a result of the comparison in the second step, if the progressive percentage is less than or equal to the call acceptance rate, the incoming call and the allow call variable are increased, and the call admission message is transmitted to the call admission control function. Transmitting a call release request message to a call admission control function; And After performing the third step, it is determined whether the incoming call variable has a predetermined value, and if the predetermined call does not reach the predetermined value, the message transitions to the message waiting state, and when the incoming call variable reaches the predetermined value, the incoming call and the allowed call variable are reset. And a fourth step of transitioning to the message waiting state after initialization. The method of claim 1, The predetermined value of the fourth step is A percentage control method for traffic congestion control, characterized in that 100.