KR20040047476A - Method for call information release of Switched Virtual Circuit in Asynchronous transfer Mode System - Google Patents

Abstract

PURPOSE: A method for canceling call information of an SVC(Switched Virtual Circuit) in an ATM system is provided to cancel unnecessary call information by using a health check system, so that the unnecessary call information cannot be continuously accumulated, thereby supplying a smooth service. CONSTITUTION: When a main health check message is received, the second processor(130) perceives processors for all signaling-completed call information(300). If the processors adjacent to the second processor(130) are decided as the first processor(120) and the third processor(140), the second processor(130) transmits a health check inquiry message to the first and third processors(120,140) to inform that a self call status is active(310). If the health check inquiry message is received, the first and third processors(120,140) confirm a call reference ID included in the health check inquiry message, include self call status information in an HCSM(Health Check Status Message), and transmit the HCSM to the second processor(130)(320). The second processor(130) confirms status information of the call reference ID, and compares the information with a self status(330).

Description

Method for call information release of Switched Virtual Circuit in Asynchronous Transfer Mode System}

The present invention relates to a private asynchronous transmission mode system, and more particularly, to a method for releasing unnecessary call information for overcoming an error of switched virtual line call information in a private asynchronous transmission mode system.

In general, Asynchronous Transfer Mode (ATM) is a technology that can freely change the bandwidth during low-speed communication to high-speed broadband communication, and divides the information sent from the transmitting terminal to the receiving terminal by 48 bytes. The data is sent in units of 53 bytes of a cell with 5 bytes of headers in the destination level information.

The cell header may include a virtual path identifier (VPI) for identifying which virtual path to use, and a virtual channel identifier for identifying whether it is preferable to transmit data using one of the virtual channels. VCI: Vritual Channel Identifier).

In such an asynchronous transmission mode (ATM) network, it is possible to maintain a point-to-point connection through multiple systems and virtual circuits through physical connections. Such a virtual line is divided into a permanent virtual circuit (PVC) and a switched virtual circuit (SVC).

The permanent virtual circuit (PVC) is a method in which a communication path is fixedly established with a predetermined counterpart even without performing a communication path setting / release procedure. However, since the virtual path identifier and the virtual channel identifier are limited to 24 bits uniformly, the system size that can be accommodated in the permanent virtual circuit system is limited. And since the channel of the line is always connected, it must have identifier information for each node of the network, which has the disadvantage that the memory becomes larger than necessary.

On the other hand, the switched virtual line (SVC) is a method of establishing / releasing a communication path every time communication is established, establishing a logical communication path by a calling procedure defined before communication, and releasing the communication path after performing all communication. to be. This switched virtual line (SVC) is a method of selecting and communicating with an arbitrary counterpart and is used when there are many state users to communicate with or when overhead due to setting / release of a communication path is not a problem.

In the asynchronous transmission mode network using this method, the interface between independent systems uses a signaling protocol established by the ATM Forum and ITU-T (eg, UN4.0 of ATM FORUM, PNN1.0 and Q.2931 of ITU-T). It can be operated as a signaling protocol for a switched virtual circuit between two networks. At this time, in the asynchronous transmission mode system during operation, when an error occurs due to a temporary failure on a transmission path or a malfunction of a switching system, a signaling message type of "STATUS ENQUIRY" and "STATUS" as a response is provided to overcome the error of mutual call information. Specify in advance. Therefore, it overcomes the error of mismatch of call information that can occur in the interface between asynchronous transmission mode system. Error overcoming of the mismatch of switched virtual circuit call information is specified in the standard (ITU-T, ATM-Forum) protocol operating at the network interface point.

Meanwhile, a signaling message transmission method in a private asynchronous transmission mode system uses a connection-oriented protocol, which is a protocol that guarantees reliable message transmission. However, in an environment not using the connection-oriented protocol, since accurate message transmission cannot be guaranteed, call information between signaling points may still be inconsistent. This inconsistent call information can accumulate continuously, resulting in a shortage of resources, resulting in errors in the operating service and difficulty in performing the overall system.

Accordingly, an object of the present invention is to provide a method for overcoming an error about a mismatch of call information generated in an asynchronous transmission mode system in an environment in which accurate message transmission cannot be guaranteed.

Another object of the present invention is to provide a method for releasing unnecessary call information of a switched virtual line by performing a health check in an asynchronous transmission mode system.

The method for achieving the object of the present invention is a method for releasing unnecessary call information by using a health check method in an asynchronous transmission mode system that includes a plurality of processors in an asynchronous transmission mode network, using a switched virtual line method, A process of instructing a health check to the neighboring processors at a predetermined period in the main processor, identifying a call state of other adjacent processors in each of the neighboring processors that have received the health check command, and determining the call state as a result And if the call state information stored in the call state information of the identified processor is inconsistent with the stored call state information.

1 is a block diagram showing the configuration of an asynchronous transmission mode system according to an embodiment of the present invention;

2 is a flowchart illustrating an operation of a main healthy check message according to an embodiment of the present invention;

3 is a timing diagram illustrating a healthy check procedure according to an embodiment of the present invention;

4 is a flowchart illustrating a healthy check operation according to a message received from peripheral processors according to an exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings.

In addition, in the following description, many specific matters such as specific messages and the like appear, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific matters. It is self-evident to those who have knowledge. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram showing the configuration of an asynchronous transmission mode system according to an embodiment of the present invention.

Referring to FIG. 1, the asynchronous transmission mode system 100 may include first and fourth processors (SPs) 120, 130, 140, and 150 and a main processor capable of always communicating with all processors. MSMP: Main Signaling Management Processor (110). The main processor 110 can communicate with all processors in the asynchronous transfer mode system 100. The peripheral processors 120, 130, 140, and 150 transmit and receive messages for performing a health check to release unnecessary call information.

2 is a flowchart illustrating the operation of a main healthy check message according to an embodiment of the present invention.

Referring to FIG. 2, the operation of the main processor 110 is performed. The main processor 110 waits for a timer signal indicating that the health check is performed at a predetermined period in step 200, and then receives the message in step 210. Is a message of a timer signal. If it is not a message, the process returns to step 200 and waits for a timer signal. On the other hand, if the timer signal is received in step 220 transmits a health check command message for the health check to all the processors (120, 130, 140, 150, etc.) located around the main processor 110 and then returns to step 200 Wait for timer signal.

The health check checks the state of a call established in the asynchronous transmission mode, and transmits and receives a health check state question message and a health check state message to determine a state between processors to which the call is set. Perform a health check.

The health check command message and the corresponding messages will be described. The main health check message (MHCM) is transmitted from the main processor 110 to all peripheral processors communicating with the main processor 110. Command message for health check. It has a structure as shown in Table 1 below.

Information Element Explanation Mess type A command for performing a health check sent to all processors present in the system, and is transmitted from the main processor (MSMP).

When the peripheral processors of the main processor 120 receive the health check message from the main processor 110, the neighbor processors process the health check status question message for the call that has already completed signaling among the switched virtual circuit call informations that are managed. (HCEM: Generate Health Check Status Inquiry Message). The health check status question message (HCEM) has a structure as shown in Table 2 below.

Information Element Explanation Mess type This is a status question message inside the system. Near End Call Reference It is your call reference ID. Near End Call State Call status for its call reference ID and is always "ACTIVE" since it is sent for a call that has already been signaled. Far End Call Reference Call reference ID of the peripheral processor associated with its call reference ID in the peripheral processor, which is the call reference ID in the processor that received this message.

As shown in Table 2, the health check state question message includes a message type, its own end end call reference and state, and a health check state question message. It includes call end ID information of a neighbor processor.

In response to the health check status question message, the neighboring processors transmit a health check status message (HCSM) to the processor that transmitted the health check status question message as a response to the health check status question message. The health check status message (HCSM) is formed in the form as shown in Table 3 below.

Information Element Explanation Mess type Indicates that the message is a response to a status question inside the system. Near End Call Reference It is your call reference ID. Near End Call State Call state of the call reference ID.

As shown in Table 3, the health check state message includes a message type, its own call end ID, and state information. The processor receiving the response through the health check status message analyzes the received health check status message and executes the health check progress module for the actual recovery thereof.

The health check operation will be described with reference to the drawings using these messages as follows.

3 is a timing diagram illustrating a healthy check procedure according to an embodiment of the present invention.

Referring to FIG. 3, the main processor 110 periodically transmits a start command message for starting the health check to all the processors 120, 130, 140, and 150. Since the main processor 110 can communicate with all the processors in the asynchronous transfer mode system 100, it is possible to deliver a main health check message that is a start message to all processes. When only the message transmission / reception operation of the second processor 130 among the processors that receive the main health check message will be described.

When the second processor 130 receives the main health check message from the main processor in step 300, the second processor 130 identifies the corresponding processors for all the call information for which signaling has been completed.

If it is determined that the processors adjacent to the second processor are the first processor 120 and the third processor 140, the second processor transmits a healthy check question message to the first processor 120 and the third processor 140 in step 310. Send a signal indicating that its call status is "active".

When the health check question message is received in step 320, the first processor 120 and the third processor 140 check the call reference ID included in the health check question message and include their call state information in the health check state message. To be transmitted to the second processor 130.

In operation 330, the second processor 130 receiving the health check state message checks the state information of the corresponding call reference ID and compares the state information with its own state. At this time, if the status information of the second processor 130 is also "ACTIVE" and the status information received from the first processor 120 and the third processor 140 is "ACTIVE", the call information between the two processors (120, 130) The health check processing module is not performed because it matches. On the other hand, if the state information of the second processor 130 is "ACTIVE" and the state information received from one of the first processor and the third processor 140 is not "ACTIVE", the processors 120, 130, 140 ) Call information is inconsistent. Accordingly, in operation 340, the second processor 130 releases call information related to the call of the first processor 120 and the third processor 140, and calls the first processor 120 and the third processor 140. A call release procedure of signaling is performed by transmitting a release message. Here, the call release procedure of signaling follows the internal protocol of individual network.

4 is a flowchart illustrating an operation related to a health check according to a message received by a processor according to an exemplary embodiment of the present invention.

Herein, the operation according to the reception of the message by the second processor among the processors performing the health check will be described with reference to FIG. 4. When the random message is received in step 400, the second processor 130 in step 410 is performed. Analyze the received message.

If the received message is the main health check message from the main processor 110, the second processor 130 sets the call reference ID to "1" in order to identify the call set in step 421. Then, in step 422, it is checked whether its call state corresponding to the call reference ID (# 1) is "ACTIVE". In this case, in step 423, the address and the call reference ID associated with the call reference ID # 1 are identified, and in step 424, the health check question message is transmitted to the peripheral processor related to the call. On the other hand, in step 422, if it is not "ACTIVE", step 425 is performed.

In step 425, the second processor 130 increases the call reference ID to determine call state information of the next set call, and then determines whether the call reference ID exceeds the maximum value in step 426. If the call reference ID is larger than the maximum value, the operation ends. Otherwise, the process returns to step 422 to determine call state information of the next processor.

On the other hand, in the case of the health check question message received from the peripheral processors as a result of the analysis in step 410, the second processor 130 grasps the call state information associated with the call reference ID (# 1) in step 431. In operation 432, the second processor 130 transmits a health check status message including the identified call state information to the query processor in response to the health check status question mesh, and then ends the operation.

On the other hand, when receiving the health check status message including the call state information from the neighboring processors as a result of the analysis in step 410, the second processor in the step 441 associated with its call state information and call reference ID (# 1) Compare the call state information received from the processors. As a result of the comparison, if all the state information of all the processors match, the operation ends. On the other hand, if the call state information of any one of the peripheral processors and their call state information does not match, in step 442 all the information about the call of the call reference ID (# 1) is determined as unnecessary call information In step 443, the call release message is transmitted to the neighbor processors, and the operation ends. Accordingly, the peripheral processors also release all information of the call corresponding to the current call reference ID.

The health check is performed by all processors that receive the main health check message, which is a health check command message, at a predetermined period from the main processor. In addition, as long as the processor can communicate with all the processors in the system, other processors can act as the main processor. However, only one processor plays a role in the main processor of the system.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention releases the mismatched call information by using the health check method, so that the mismatched call information does not continuously accumulate so that unnecessary resources are not increased and smooth service can be performed.

Claims (4)

In the asynchronous transmission mode system comprising a plurality of processors for processing a call of the switched virtual circuit, each of the processors in the method for releasing unnecessary call information, Receiving a health check command from a main processor to neighboring processors at predetermined intervals; Determining a call state corresponding to other adjacent processors that have received the health check command; And releasing the call information when the identified call states of the other processors are inconsistent with their call states. The method of claim 1, wherein releasing the call information comprises: Sending a health check status question message to determine the call status to the other processors; Receiving a health check state message including call state information in response to the health check state question message; Determining call state information included in the health check state message and determining whether the call state information is identical to the call state information; If the call state information does not match, release the call information and send a call release message to the other processor. The method of claim 2, The other processors receiving the health check status question message including a call reference ID further include determining an address corresponding to the call reference ID and its own call reference ID to determine a call state. Said method. The method of claim 3, Wherein the call reference ID is arbitrarily assigned to identify calls to perform a health check in the processor that sent the health check question message.