KR960009465B1 - Network resource management using virtual path loopback - Google Patents

Abstract

checking the generation of OAM pattern; returning to the initial step when trouble is removed; checking whether the traffic is smaller than a critical value; for activating performance measurement when the traffic is smaller than the critical value and returning to the initial step in case of performance measurement nonactivated state; checking whether OAM cell is looped back before a timer is completed when the traffic is not smaller than the critical value; and returning to the initial step when it is looped back but transmitting trouble managing cell when it is not looped back.

Description

Network Resource Management Using Virtual Path (VP) Loopback

1 is a loopback structure diagram for explaining the present invention.

2 is an OAM cell format diagram of the CCITT Recommendation, and (b) an OAM cell format diagram according to the present invention.

3 is a flowchart illustrating a whole process of a network resource management method using a virtual path (VP) loopback according to the present invention.

4 is a flowchart illustrating a case where a cell having an OAM type of fault management and a function of AIS is generated.

5 is a flowchart illustrating a case where a cell in which an OAM type is Fault Management and a function type is FERF is generated.

FIG. 6 is a flowchart of processing when an OAM type generates cells that are activated and deactivated for performance monitoring.

7 is a processing procedure for the case where a cell in which the OAM type is performance management and the function is forward monitoring is generated.

The present invention relates to a network resource management method using a virtual path (VP) loopback.

In general, network management refers to a series of operations for observing and controlling a network in real time in order to optimize network performance even under obstacles such as overload or failure.

As telephone, a popular means of communication, has been widely used, efficient network management has been performed automatically in centralized network management centers on a per exchange basis at the level of simply limiting calls by the attendant.

In order to efficiently control the traffic that flows into the network, it is necessary to use the network resources as much as possible while preventing collisions, overloads, and failures.

Currently, there are two types of network management functions of electronic switchboards: automatic control methods that are automatically and dynamically handled for various situations that are found internally of the exchanges, and manual control methods which take control measures according to the operator's judgment on network overload conditions.

In the automatic control method, there is an HTR control function that detects and handles an incoming code such as a hard-to-reach (HTR) call that has significantly reduced call completion rate due to congestion in the network, and a relay line reservation control function to give priority to the congestion. .

However, the current network management function does not provide automatic control in the practical sense of efficiently exchanging status information, availability and performance information during the exchange period. This is because there is a problem of inconsistency of interface and overhead problem of configuring a separate signal network system in different exchange periods.

In order to efficiently perform network management, the status, availability, performance, and configuration information of the exchanges should be exchanged during the exchange period for the purpose of network management.The status information is the result of comparing the current load level with a threshold value or any abnormality found. Information on the operational status and should be communicated to other exchanges or network management centers in real time.

Therefore, in broadband communication with various services and high data rates, a more efficient state information transmission and node-to-node failure detection method is required to satisfy real-time demand conditions.

In the broadband communication system, because of the dynamic bandwidth and high data transmission rate, the automatic control method that monitors the state of the manganese line periodically before the congestion occurs and dynamically responds to the traffic change rather than taking any action after the congestion occurs. Required.

The present invention has been made to solve the problems of the prior art and to meet the demands according to the present invention is to loop back the OAM (Operation And Mainteance) cell in the manganese to detect the occurrence or failure of the communication line, and the congestion state, The purpose is to provide an efficient network resource management method using virtual loop (VP) loopback that defines and realizes the OAM cell type and function for performance management.

In order to achieve the above object, the present invention, in the network management resource method using a virtual path (VP) loopback, whether the OAM (Operation And Maintenace) form of the failure management and the function of the AIS (AIarm Indication Signal) is generated? A first step of investigation; A second step of returning to an initial process after the first step is performed, and the function is an AIS failure management cell whose function is AIS; A third step of investigating whether traffic transmitted between endpoints is smaller than a threshold value or at the request of an operator after performing the first step; After performing the third step, a fourth step of activating the performance measurement if the traffic transmitted between the endpoints is smaller than the threshold or at the request of the operator, and returning to the initial process if the performance management cell is inserted by inserting the performance management cell; After performing the third step, if the traffic transmitted between the endpoints is not smaller than the threshold value or is not required by the operator, the OAM loopback cell is periodically inserted from one endpoint to the other, the timer is activated, and the cell returns. A fifth step of examining whether the OAM cell has looped back successfully before the timer expires; And after performing the fifth step, if the loop state is successful and returns to the normal state, the process returns to the initial process, and if it is not looped back, the failure occurs between the end points. Therefore, when the failure is released by transmitting a failure management cell, which is a far end receive failure (FERF) And a sixth step of returning to the process.

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

FIG. 1 is a loopback structure diagram for explaining the present invention, wherein (A) is an end-to-end in which a loopback cell is inserted by a virtual path (VP) end point and a cell is looped back at a corresponding virtual path (VP) end point. End loopback is a structure that shows that the loopback function at the Asynchronous Transfer Mode (ATM) layer can insert operation information at any end point without any service disruption to an already established connection and is returned from another destination location.

This feature can insert loopback OAM cells on a virtual path connection. This cell loops back to the specified location with specific information.

FIG. 1 (B) is a network endpoint loopback where a loopback cell is inserted by a network and looped back at a corresponding virtual path endpoint, which is an arbitrary virtual path (VP) at the request of a Telecommunication Management Network. This is a structural diagram showing that the loopback function is used for the purpose of fault management or performance measurement of an endpoint.

This cell loops back to the specified location with information from the network management system or information fields within the cell at the specified location.

FIG. 1 (C) is a structural diagram showing that a loopback cell is inserted by an arbitrary node and that a loopback function can be gradually performed on a corresponding neighboring node, thereby enabling efficient failure detection.

The loopback cell is inserted by the virtual path (VP) endpoint and looped back to the address specified by the loopback location identifier.

Figure 2 (A) is the OAM cell format diagram of the CCITT Recommendation, (b) is an OAM cell format diagram according to the present invention, using a loopback cell to efficiently perform functions such as testing, fault detection, performance measurement, etc. In order to perform, the information field of a cell is classified into two parts, a common field and a field that changes according to a function.

The common field is a part common to all OAM cells, and is divided into an OAM form and a functional form.

The OAM type sets the functions obtained by inserting an OAM cell into a specific bit type so that the cell can recognize what the cell is to do and what function the cell performs. In the present invention, the loopback cell is used. It is classified into three types, activation / deactivation for fault management, performance management, and performance measurement, which can be extended later.

Looking at the function of the defined field in detail:

ATM header fields take the form commonly used in asynchronous transmission.

As described above, the OAM type field is classified into three types of functions obtained by inserting an OAM cell. The OAM type field indicates a type of an OAM cell for a specific purpose such as failure management and performance measurement.

A function type is a field indicating a function that is actually applied to a specific type field of an OAM cell of a field and is a field used to define detailed functions to be taken for each OAM type cell.

In the present invention, a detailed function is defined in (b) for each OAM type, which can be extended later when the function is added, and the function types for each OAM type are as follows.

First, if the OAM type is failure management, the detailed function for this is a function type that performs the functions of Alarm Indication Signal (AIS), Far End Receive Failure (FERF), Testing, and Loopback OAM Cell. Coded in the form.

Next, when OAM type is performance management, the detailed functions for this function are forward monitoring, backward repotihg, status reporting, and loopback OAM. Is coded as

And, if the OAM type is Activation / Deactivation, the detailed function for this function is to perform a function of requesting and responding to the network management network or user to activate the performance measurement for performance monitoring. The functional form exists and is coded in a specific bit form.

Next, the loopback indication field is a field indicating that the loopback was successful by changing this octet at the destination where the loopback has occurred, so that an infinite loopback can be prevented.

The Correlation Tag field is used to indicate a correlation between the transmitting OAM cell and the receiving OAM cell. In particular, when the OAM type is performance management and performs a forward monitoring function, this field can detect error information about the monitoring cell and a cell into which an error is inserted.

The loopback location ID field is used to indicate the address of a specific node where the loopback should occur and may reduce overhead that may occur when transmitting to two or more receiving nodes.

The source ID field is used to recognize the source from which the loopback cell was generated at the receiving side of the cell.

The error detection code field (EDC) indicates a CRC-10 error detection code calculated for the information field of the OAM cell, and the polynomial is as follows.

G (X) = 1 + X + X ⁴ + X ⁵ + X ⁹ + X ¹⁰

3 is a flowchart illustrating the entire process of a network resource management method using a virtual path (VP) loopback according to the present invention.

First, it is examined whether a cell with OAM type fault management and a function of AIS (Alarm Indication Signal) is generated (1). If the result of the investigation (1) is a fault management cell with AIS, it is notified to a fault handling routine. After the action is taken (2), it is examined whether the fault is released, and if the fault is not cleared, the fault management cell returns to the process (2), and if the fault is cleared, it returns to the initial process (3).

As a result of the investigation (1), it is examined whether the traffic transmitted between the endpoints is smaller than the threshold TI or at the request of the operator (4).

Investigation (4) shows that if the traffic transmitted between the endpoints is less than the threshold TI or at the request of the operator, the performance measurement is activated (5), the performance management cell is inserted (6) and the performance measurement is disabled. Otherwise, the process returns to the process (6), and if it is inactive, the process returns to the initial process (7).

If the traffic transmitted between the endpoints is not less than the threshold TI or not at the request of the operator, the OAM loopback cell is periodically inserted from one endpoint to the other, the timer is activated, and the cell returns. Wait (8) to check whether the OAM cell has looped back successfully before the timer expires (9) if the loop has successfully looped back, return to the initial process because it is normal, or if there is a failure between endpoints, send a FERF fault management cell. (10) If the fault has been released, return to the initial process (11).

4 is a flowchart illustrating a case where a cell in which an OAM type is failure management and a function is an AIS (Alarm Indication Signal) is generated.

When the ATM layer receives a warning signal from the physical layer when a specific error occurs in the connection path or hardware device, the node that receives the warning signal creates a cell with OAM type failure management and AIS function and periodically connects to the node connected to it. Transmit (30). This informs connected nodes that this channel is unavailable while the fault condition is not cleared.

The node receiving the AIS cell reports the failure information, monitors the AIS cell continuously transmitted (31), and waits for the failure condition to be released (32).

In this case, when the AIS cell is not received even after a certain time or the valid cell or the continuity check cell reaches the receiving node, the failure processing is completed and the normal cell is considered to arrive in normal operation.

FIG. 5 is a process diagram for the case where the OAM type is the fault management and the function type is the FERF cell.

If the OAM loopback cell periodically transmitted between user cells does not return normally from the destination node (34), the transmitting node considers that any failure has occurred on the communication connection and immediately switches to the failure management state.

At this time, the transmitting node generates an OAM cell in which the OAM type is failure management, and the function type is performing the test, and gradually transmits the cell to the destination node from a nearby neighbor node (35).

When a failed node is detected, an FERF cell is generated immediately and periodically sent to the node connected to it. This informs connected nodes that this channel is unavailable while the fault condition is not cleared.

The node receiving the FERF cell reports the fault information, monitors the FERF cell that is continuously transmitted, and waits for the fault condition to be released.

In this case, when the FERF cell is not received even after a certain time or when the valid cell, the user cell, or the continuity check cell arrives at the receiving node, failure processing is completed and the normal cell is considered to arrive in normal operation.

6 is a flowchart illustrating a case where an OAM type generates cells that are activated and deactivated for performance monitoring.

Performance monitoring for any channel is performed by measuring the transmission performance of the user cell at any node, and sending and receiving information on the detected result between endpoints. However, even if the path is already set, after inserting and transmitting the performance monitoring information regardless of the actual user information, after confirming whether the status between each node is enough to accommodate the added performance monitoring information, By sending and receiving actual performance management information, unnecessary overhead may be reduced by inserting unnecessary information on the path. Looking at the process for this in detail as follows.

If the network management network or the user requires a performance measurement for the connection between two endpoints, one side (A) requires the other side (B) to activate the performance measurement (37).

On the other hand, the other side B decides whether to reject or accept this request in consideration of its own state, and informs one side A of the request.

As described above, when it is determined to enable performance monitoring between both nodes, the transmitting node and the receiving node are immediately switched to the performance management state and generate a cell in which the OAM type is the performance management.

Detailed functions of this cell type include forward monitoring, backward reporting, status reporting and loopback OAM cell functions.

7 is a flowchart illustrating a case where a cell having an OAM type of performance management and a function of forward monitoring is generated.

Performance monitoring for any path is performed by measuring the transmission performance of the user cell at any node and sending and receiving information about the detected result between the endpoints, where the network management network or the user connects between node A and node B. In the case of requesting the performance measurement for, the performance management state is activated through the process of FIG. 6.

If the Node B accepts the performance measurement, it inserts a watch cell repeatedly for n user cells from the time of acceptance (38).

Receiving side detects whether there is an error for each monitoring cell and the cell inserted as an error, and collects statistical data about it.

In addition, when a transmitter adds a time-stamp to an information field and transmits the information field, a cell transmission delay occurring when a cell is transmitted between two nodes can be measured.

Such information may be transmitted to the sender in a cell in which the OAM type is performance management and the function is backward reporting.

Periodically or when an idle cell is transmitted, a failure may occur in the performance management state by checking whether the cell is successfully looped back by sending a cell with OAM type performance management and function loopback to the receiving side. Can cope with errors

OAM type is the performance management and status reporting (cell) of status reporting (Status reporting) occurs in the following cases.

Existing switch network controls the congestion status or line failure by providing a separate signal path to communicate network management information during the exchange using the common line preference method (SS NO.7), but does not use a separate signal channel. The OAM cell type is a performance management and a cell whose function is a status report can be inserted to transmit information, such as bandwidth, routing information, and line failure, available between arbitrary nodes to adjacent nodes.

In addition, this information is used to transmit information required between nodes such as a transmission function of a hard to reach (HTR) code and a congestion exchange message to a cell of such a form.

The performance monitoring or performance management functions can be operated when the connection is established or when the connection is already established. This operation is mainly activated and deactivated by the network management network.

In the event of a failure in the currently established communication connection, any faulty node can be inferred from the returned loopback cell. In this way, congestion can be prevented by preventing further load on the exchanged exchange.

In addition, the user can generate end-end-loopback for the purpose of operation without the intervention of a specific signaling method or operation system (OS).

The present invention configured and operated as described above does not depend on a specific signaling method for information to be provided between arbitrary nodes for network management purposes, and simply inserts an OAM cell periodically during data transmission, thereby simplifying the interface between the heterogeneous nodes. By inserting the loopback cell periodically, problems such as line abnormalities and failures that may occur on the communication line can be predicted without the help of separate detection equipment.

Claims (3)

A network management resource method using a virtual path (VP) loopback, comprising: a first step (1) of examining whether an OAM (Operation And Maintenance) type is generated; A second step (2, 3) of performing a first step (1) and then returning to an initial process when the fault management cell has a function of AIS and the fault is released; A third step (4) of checking whether the traffic transmitted between the endpoints is smaller than the threshold value or at the request of the operator after performing the first step (1); After performing the third step (4), if the traffic transmitted between the endpoints is less than the threshold or at the request of the operator activates the performance measurement and inserts a performance management cell to return to the initial process if the performance measurement is inactive Steps 5-7; After performing the third step (4), if the traffic transmitted between the end points is not smaller than the threshold or not at the request of the operator, the OAM loopback cell is periodically inserted from one end point to the other end, and after activating the timer, the cell A fifth step (8, 9) of waiting for a return and checking whether the OAM cell has looped back successfully before the timer expires; After performing the fifth step (8, 9), if the loop is successfully looped back to the normal state, if the loop is not looped back to the initial process, and if the failure occurs between the end points, by transmitting a failure management cell of FERF (Far End Receive Failure) And a sixth step (10, 11) of returning to an initial process when the failure is cleared. The method of claim 1, wherein the second steps (2, 3), the OAM at the node that receives a signal when a specific error has occurred in the connection path or hardware device from the physical layer to the ATM (Asynchronous Transfer Mode) layer A first step of generating a cell having a type of failure management and a function type of AIS and periodically transmitting it to a node connected thereto; After performing the first process, the node receiving the AIS cell reports the fault information, monitors the AIS cell continuously transmitted and waits for the fault condition to be released; After performing the second process, if the AIS cell is not received for a predetermined time or the valid cell or the continuity check cell arrives at the receiving node, the failure processing is completed and the normal cell is regarded as normal to arrive. Network resource management method using a virtual path (VP) loopback, comprising three processes. The method of claim 4, wherein the activation of the performance measurement in the fourth step (5 to 7), if the OAM loopback cell periodically transmitted between user cells does not normally return from the destination node, the transmitting node returns to a failure management state. A first step 35 of generating an OAM cell in which an OAM type is failure management and a functional type is testing by switching, and transmitting a cell from an adjacent node to a target node; And after performing the first process 35, if a node having a failure is detected, an FREF cell is immediately generated and periodically transmitted to a node connected to the node. The node receiving the FERF cell reports the failure information and continues to transmit. And a second step (36) of monitoring a FERF cell and waiting for a failure condition to be released to perform a normal operation.