KR0179178B1 - Traffic run away control method using the optimum traffic priority choice method - Google Patents

Abstract

The present invention relates to a traffic congestion control method in an asynchronous delivery mode switching system, etc., and is located in front of a call connection accepting function existing in a call connection control processor such as an asynchronous delivery mode switching system, and selects an optimal traffic priority before number translation for call connection. In order to provide a traffic congestion control method for controlling traffic congestion using a scheme, a first step of receiving the overload control signal to trigger the function of the optimal traffic priority selection scheme to determine the size of the call gap and to set the relay line number; Requests the current remaining relay bandwidth of the relay line number, compares the current remaining relay bandwidth value with the predetermined current relay bandwidth value with a predetermined threshold, sets the current remaining relay bandwidth value according to the comparison result, calculates the free bandwidth, and Setting a second step; Collecting a call setup message flowing into the relay line number within the call cap time and selecting a call according to an optimal traffic priority selection scheme; And transmits a setup message of the selected call to the call admission control function block and sends a call release message for the dropped call, blocks the call, checks whether the newly arrived overload control release message arrives at the call gap time, and the release message arrives. If not, the first step, and if not arrived, including the fourth step to go to the second step can prevent fatal damage including system down, and the effect of maintaining the system performance at the maximum design capacity have.

Description

Traffic Congestion Control Using Optimal Traffic Priority Selection Techniques

1 is a structural diagram of an embodiment of an asynchronous delivery mode (ATM) virtual channel exchange system to which the present invention is applied.

2 is a conceptual diagram of call determination using an optimal traffic prioritization (BFF) scheme according to the present invention.

3 is a flowchart illustrating an embodiment of a traffic congestion control method according to the present invention.

* Explanation of symbols for 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: relay call processor 18: internal switch network module

19: operational maintenance processor

According to the present invention, the Asynchronous Transfer Mode (ATM) switching system is released from an overload condition, and an optimal traffic priority selection is made to accept a call service request from a user when an overload is detected to optimize network performance. : Traffic congestion control method to control using Best Fit First.

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

Such overload or congestion may occur due to natural disasters, breakdowns in specific exchanges, or dominoes resulting from concentrated call service requests to their exchanges, and major popular programs such as TVs. This can occur when you can anticipate the concentration of call service needs.

In any case, if a call service request is congested to a particular called number, the system may be overloaded due to the fact that many calls are not allocated signaling channels or call requests exceeding the design capacity of the Call Admission Control (CAC). Or the system is forced to provide call services less than its design capacity, and the system may eventually crash. If this situation is left unattended, it will affect the corresponding exchanges and the adjacent exchanges, which in turn will have a significant adverse effect on the entire network.

In the conventional public telephone network (PSTN) or narrowband integrated information network (N-ISDN), a method of suggesting call inflow into the system in order to reduce the congestion and the load on the system, such as a percentage limit method and a call dap method. Was used.

Percentage control method is a method that accepts call requests according to the restriction class without condition for call gap requests arriving at the congested and overloaded system by placing a percentage by class according to the congestion situation. Although there is a difference, the basic technique is to accept only a certain number of call requests within a predetermined time interval by using a timer in the exchange.

The conventional congestion control method described above is suitable for resource management in a circuit-based switching system in which one call is set to 64 Kbps, but resource allocation for one call in a newly implemented Asynchronous Transfer Mode (ATM) based switching system. The distribution by this statistical multiplexing makes it difficult to take sensitive responses and measures against the occurrence of overload and congestion created on a per-call basis.

Therefore, in order to cope with the congestion and overload occurrence of the asynchronous transfer mode (ATM) exchange using the broadband communication method, the resource management such as the call unit concept and bandwidth (Bandwith) must be simultaneously approached.

As the exchange system becomes more loaded with time as the system is in operation, the system's performance increases until the system's load reaches a certain limit, and beyond that limit, the performance, or processing power, is significantly reduced. The system may crash after an arbitrary time without proper action. This worst-case scenario is avoided in advance, and the system's performance is continuously required for congestion and overload.

Accordingly, the present invention is located in front of a call connection acceptance function (CAC) existing in a call and connection control processor (CCCP) such as an asynchronous transfer mode (ATM) exchange, so that the optimal traffic before the number translation for the call connection. An object of the present invention is to provide a traffic congestion control method for controlling traffic congestion by using a best fit first (BFF) technique.

In order to achieve the above object, the present invention provides a traffic congestion control method in which a resource allocation for one call is applied to a switching system distributed by statistical multiplexing. Step 1: Determine the size of the call by setting the function and set the relay line number: Request the current residual relay bandwidth (CRTBW) of the relay line number and compare the current residual relay bandwidth (CRTBW) value with a predetermined threshold value. According to the comparison result, step 2: setting the current remaining relay bandwidth (CRTBW) value and calculating and setting the bandwidth (PBW): collecting the call setup message flowing into the relay line number within the call gap time (CGT) to select the optimal traffic priority ( Step 3 of selecting a call according to the BFF) technique, and sending and dropping a setup message of the selected call to a call admission control function (CAC) block. In case of a call being received, a call release message is transmitted to block a call, and then, whether the newly arrived overload control release message arrives at the call gap time is checked. If the release message arrives, the process proceeds to the first step. Characterized in that it comprises a fourth step that goes to the second step.

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

1 is a structural diagram of an embodiment of an asynchronous delivery mode (ATM) virtual channel switching system to which the present invention is applied.

The Call Connection Control Processor (CCCP) 15 is a processor that performs call processing of a general subscriber using a User Network Interface (UNI) protocol, and is a subscriber interface module (SIM). 13) together with the traffic control function such as call admission control, UPC (Usage Parameter Control).

Trunk Call Processor (TCP) 17 is a processor that performs call processing with a network using a network node interface (NNI) protocol and includes a trunk interface module (TIM). 16) In addition, it performs call connection control function for incoming and outgoing calls and manages the functions necessary for matching with network.

Operation and Maintenance Processor (OMP) 19 oversees the functions related to billing, statistics, maintenance and operation management in the system.

The Access Switch Network Module (ASNM) 14 is a non-blocking magnetic routing switch in ASM that transmits asynchronous transfer mode (ATM) cells on a basic basis. An interconnection switch network module (ISNM) 18 is a magnetic routing switch used as an interconnector between ASMs.

The statistics block and the overload block of the asynchronous transfer mode (ATM) system periodically measure and collect the performance parameters of the system to calculate the load of the system and reach the overload threshold value at which the system performance is significantly reduced. (ATM) Trigger the congestion control function on the in-flight network management block. At this time, the restriction of call inflow into the congestion network limits the connection of the call arriving at the system by using the optimal traffic priority selection technique.

2 is a conceptual diagram of call discrimination using an optimal traffic priority selection (BFF) scheme according to the present invention.

Looking at the call discrimination method using the Best Fit First (BFF) method in detail, the call inflow control function of the optimal traffic first selection method in the network management block receiving the congestion control signal from the overload block is first called the call gap size. (Call Gap Size) was set, and the current remaining relay bandwidth (CRTBW: Currunt Residual Trunk Band Width) was obtained by requesting the remaining allocable bandwidth of the relay line that received the control request by the call admission control function (CAC).

Once the current remaining relay bandwidth (CRTBW) is determined, the Preband Band Width (PBW) is calculated and set, and the traffic in the setup message of the calls requiring connection to the restricted relay line arriving at subscriber matching module 13 within the call gap. The Peak Cell Rate (PCR) of the Traffic Descriptor is collected so that the maximum Cell Rate (PCR) value of the call and the current remaining relay bandwidth (MAXLBW) are not exceeded. The call with the minimum difference of CRTBW) is selected as the call of the optimal traffic priority selection (BFF) technique. Once the call of the optimal traffic priority selection scheme is selected, the call ingress control function sends a setup message for the selected call to the call admission control function (CAC) and requests the current remaining relay bandwidth (CRTBW) back to the call admission control function (CAC).

3 is a flowchart illustrating an embodiment of a traffic congestion control method according to the present invention.

The call ingress control program of the traffic priority selection (BFF) technique loaded on the system by the system loader receives the overload control signal along with the overload class and overload trunk number in the control message waiting state 31 from the overload block. (32) to trigger the function of the optimal traffic priority selection scheme.

Then, the program divides the overload control signal according to the load class to determine the size of the call gap and sets the relay line number to the program itself variable (33). The program asks the Call Admission Control Function (CAC) block for the current residual relay bandwidth (CRTBW) for the relay line number (34) and compares the current residual relay bandwidth (CRTBW) value given in response to the threshold (35) and again if it is small. If requested, if it is large, the current residual relay bandwidth (CRTBW) value is set in a program internal variable, and the reserved bandwidth (PRW) is calculated and set based on this value (36).

By collecting call setup messages that flow into the relay line number within the call gap time (CGT) (37), the call of the optimal traffic priority selection scheme is selected according to the BFF technique at the end of the call gap time. (38) The setup message of the selected call is transmitted to the call admission control function (CAC) block (39), and for the dropped call, the call release message is transmitted to the subscriber matching module 13 to block the call (40). . Finally, it checks whether a newly arrived overload control release message arrives at the call gap time, and if the release message arrives, it returns to the first state. If not, it continues to request the current CRTBW for the next call gap (41). ).

As described above, the present invention provides an effective control of call and bandwidth resources even when the call demand congestion continues, thereby preventing fatal damage including system down during system operation, and maintaining system performance at the maximum design capacity. It has an effect.

Claims (2)

In a traffic congestion control method in which resource allocation for one call is distributed by statistical multiplexing, upon receiving an overload control signal, the function of the optimal traffic priority selection (BFF) scheme is triggered to reduce the size of the call gap. Determining a relay line number; Requests the current remaining relay bandwidth (CRTBW) of the relay line number and compares the current remaining relay bandwidth (CRTBW) value with a predetermined threshold, sets the current remaining relay rental width (CRTBW) value according to the comparison result, and sets the free bandwidth (PBW). Calculating and setting a); Collecting a call setup message flowing into the relay line number within a call gap time (CGT) and selecting a call according to an optimal traffic priority selection (BFF) scheme; And transmitting a setup call of the selected call to a call admission control function (CAC) block and sending a call release message for the dropped call to block whether the newly arrived overload control release message arrives at the call gap time. And a fourth step of checking if the release message arrives and moving to the first step, and if not, moving to the second step. The method of claim 1, wherein the call selection process according to the optimal traffic priority selection method of the third step does not exceed the maximum limiting bandwidth (MAXLBW), and the difference between the maximum cell rate (PCR) value of the call and the current remaining relay bandwidth (CRTBW) is minimum. The traffic congestion control method, characterized in that to be selected as the call of the optimal traffic priority selection scheme.