KR100209347B1 - Duplication control method of linking assembly between node and node of atm communication network switchng system - Google Patents

Abstract

The present invention configures a connection structure between nodes mounted in an exchange system that performs a distributed exchange function so that an ATM matching function and an ATM user can communicate with each other in a redundant structure, and automatically controls the ATM-MSS. The present invention relates to a node-to-node connection assembly (NIA) redundancy control method of an asynchronous transmission mode information communication network switching system (ATM-MSS) that improves the reliability and stability of a node. When an error occurs, it detects it and transfers the active node-to-node connection assembly to the standby state of the node-to-node connection assembly, so that it can be operated instead, thereby providing continuous service support to the subscriber, thereby improving the stability and reliability of the system.

Description

Node-to-node connection assembly redundancy control method of asynchronous transmission mode information communication network switching system

The present invention relates to a node-to-node connection assembly (NIA) redundancy control method of an Asynchronous Transfer Mode based-Metropolitan Area Network Switching System (hereinafter referred to as ATM-MSS). Asynchronous transmission mode information communication network switching system (ATM-), which improves the reliability and stability of ATM-MSS by configuring a node interface assembly (hereinafter referred to as NIA) in a redundant structure and enabling automatic control. To a node-to-node connection assembly (NIA) redundancy control method.

At this time, the ATM-MSS is connected to the basic ATM and the synchronous digital hierarchy (SDH) using an existing pseudo-synchronous digital hierarchy (PHD) transmission line for initial ATM demand triggering and initial activation of the broadband integrated telecommunication network (B-ISDN). ATM matching for interconnecting the existing frame relay network and narrowband Integrated Information Network (N-ISDN) by using the transmission line and the cell-to-cell transmission capability and the plurality of virtual connection establishment capabilities of the ATM communication network. It is a switching system that performs a distributed switching function so that the functions and mutual communication between ATM users can be made.

ATM-MSS that performs the above functions consists of a single element management system (EMS), a single central switching node (HSN) and three remote switching nodes (RSN). There is a problem that an error occurs on a link connecting nodes or an error occurs in a node itself due to an influence or an internal cause of the system, which causes a problem in providing a normal service.

Accordingly, when the above system error occurs, the operator can control the system so that the failed link and node can be replaced with a spare link and a spare node. There is a risk that the time to find an error may be delayed, and even if it is found immediately, there is a low efficiency because there is a time required for an operator to operate the system.

In order to solve the conventional problems as described above, the present invention is to configure the node-to-node connection assemblies in a double-circuit structure, and when the error occurs using a network management system, the link and the node where the current error occurs are replaced with a spare link. It is intended to improve the stability and reliability of the system by shortening the time of error recovery by controlling the automatic replacement with a node.

1 is a block diagram of a general ATM-MSS for applying the present invention.

2 (a) is a block diagram illustrating an error on a link according to the present invention.

Figure 2 (b) is a flow chart showing a process for recovering the link error in accordance with the present invention.

Figure 2 (c) is an explanatory diagram showing the flow of traffic during the on-link error recovery process according to the present invention.

3 (a) is a block diagram illustrating an error in an inter-node connection assembly in accordance with the present invention.

Figure 3 (b) is a flow chart showing a process for recovering errors on the node-to-node connection assembly in accordance with the present invention.

3 (c) is an explanatory diagram showing traffic flow during an error recovery process on an inter-node assembly according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Network Management System (EMS) 2: Central Exchange Node (HSN)

2-1: Node Management Assembly (NMA) 2-2: Node-to-Node Connection Assembly (NIA)

2-1-1: Active Node Interconnection Assembly (NIA-A)

2-1-2: Standby node connection assembly (NIA-S)

2-3: other exchanger connection assembly (EIA)

3, 4, 5: first, second, third remote switching node (RSN)

3-1, 4-1, 5-1: Node-to-node connection assembly (NIS)

3-1-1: Active Node Interconnection Assembly (NIA-A)

3-1-2: Standby node connection assembly (NIS-S)

3-2, 4-2, 5-2: node management assembly

3-3, 4-3, 5-3: subscriber connection assembly

In order to achieve the above object, the present invention comprises the steps of duplexing the node-to-node connection assembly into the node-to-node connection assembly in an active state and a standby state; Detecting an error occurring during system operation of the redundant state; If it is detected that an error has occurred in a link between active node-to-node connection assemblies during the error detection, notifying an error to the partner node-to-node connection assembly, network management, and system in the active main node-to-node connection assembly; The node-to-node connection assembly notifying the occurrence of an error transfers the currently active node-to-node connection assembly to the node-to-node connection assembly and notifies the network management system of the transfer, and the network management system receives the transfer completion message. Instructing a node-to-node connection assembly connected to the node-to-node connection assembly that performed the transfer, and the node-to-node connection assembly receiving the command to perform a transfer and notify the network management system thereof. Recovering the error through;

If an error occurs in an active node-to-node connection assembly during the error detection, detecting an error occurrence in a standby node-to-node connection assembly of the node-to-node connection assembly in which the error occurs and notifying the network management system of the error occurrence; And at the same time, detecting an error occurrence through abnormal reception data in the active node-to-node connection assembly of the node-to-node connection assembly in which the error occurred, and notifying the network management system of the error occurrence, and the node having the error following the notification. On the system side, the node-to-node connection assembly is switched to the active state, and on the state side, the node system that has an error transfers the active node-to-node connection assembly to the network management system after the standby state is transferred to the node-to-node connection assembly. Steps Recovering the error through; Characterized in that it comprises a.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The general structure of ATM-MSS to which the present invention is applied has been mentioned above for a while. Referring to the drawings, the general structure of ATM-MSS, as shown in FIG. 1, is responsible for the entire system management and maintenance of ATM-MSS. A management system 1; It is connected to the network management system 1 to manage the nodes in the ATM-MSS, to enable the connection of each remote switching node in the ATM-MSS, and to manage the connection with the central switching node in another ATM-MSS. Exchange node 2 (HSN); and first, second, and third remote exchange nodes 3, 4, 5 (RSNs) connected to the central exchange node 2 and responsible for connecting with subscribers. .

The central switching node (2) manages all nodes in the ATM-MSS and is connected to the network management system (1) so that an error can be recovered through the network management system (1) when an error occurs in the nodes. A node management assembly 2-1; A plurality of inter-node connection assemblies connected to inter-node connection assemblies within the first, second, and third remote switching nodes 3, 4, and 5 to enable mutual exchange between each of the remote switching nodes 3, 4, and 5. 2-2); And another exchange connection assembly (EIA) 2-3 that is in charge of the connection between the center exchange node 2 and the center exchange node (not shown) in the other exchange.

The first remote switching node (3) comprises: an inter-node connecting assembly (3-1) connected to the inter-node connecting assemblies (2-3) in the central switching node (2); A node management assembly 3-2 for managing nodes connected to the inter-node connection assembly 3-1; And a plurality of subscriber connection assemblies 3-3 connected to the nodes.

The internal configuration of the second and third remote exchange nodes 4 and 5 may include internal configurations of the first remote exchange node 3 (inter-node connection assemblies 4-1 and 5-1 and node management assembly 4-). 2, 5-2) and the description will be omitted.

In addition, each of the inter-node connection assemblies 2-2, 3-1, 4-1, and 5-1 has an active inter-node connection assembly (INA-A) and a pair of spare standby ( Stand-by state node-to-node connection assembly (NIA-S), which is a redundant structure to improve system reliability, as mentioned above. The node-to-node connection assembly receives the same signal and data as received, except that the node-to-node connection assembly that is currently active transmits upon receipt. Is that.

Because of this state, it is possible to switch immediately when an error occurs, and it is possible to perform the work performed in the active state instead.

In addition, the network management system 1 is connected to the node management assembly (2-1) and the Ethernet in the central switching node (2), the central switching node (2) and remote switching nodes (3, 4) , 5) is connected via STM-1 (Synchronous Transfer Mode Level 1) level link, and the point between the central switching node (2) and the remote switching node (3, 4, 5) It has the form of a star topology that connects to points.

Looking at the operation of the ATM-MSS configured as described above, each of the remote switching nodes (3, 4, 5) is a subscriber through the subscriber access assembly (3-3, 4-3, 5-3) subscribed to it When interconnection is required while enabling communication between the two nodes, the central switching node 2 attempts to connect through the inter-node connection assembly 2-2, and the node management assembly 3-2, 4-2, 5- 2) manages the state of the nodes so that when an error occurrence signal is received from any node, the error can be recovered through the node management assembly 2-1 connected to the network management system 1.

In this case, an error may occur due to the disconnection of the link STM-1 connected between the central switching node 2 and the remote switching nodes 3, 4, and 5, or an inter-node connection. An error may occur in the assembly itself. A process of automatically recovering an error in each case will be described in detail with reference to a flowchart.

First, the protection switching process in the case of an error in the link between the node-to-node connection assemblies is shown in Figs. 2 (a) and 2 (b), and (A) indicates an error in the system. Is a schematic diagram showing the state in which the connection occurs between the remote switching node 3 and the central switching node 2 between the currently connected inter-node connection assemblies 2-1-1 and 3-1-1 (NIA-A). Indicates that an error (x) has occurred in the link connecting.

The second (b) is a flow chart illustrating the switching process in detail. When an error occurs in a link while all the systems are operating in a normal state, an inter-node connection assembly (2- Detecting a occurrence in 1-1) and declaring a corresponding kind of an error state;

Subsequently, the inter-node connection assembly (3-1-1) of the partner node system in the connected state with the inter-node connection assembly (2-1-1) through an interface processor communication (IPC) message, and network management A second step S2 of notifying the system 1 of the occurrence of an error;

At the same time as the error declaration, the node-to-node connection assembly 2-1-1 notified of the occurrence of an error replaces the node-to-node connection assembly 2-1-1 that is currently active within 50 ms. 2-1-2) attempts to perform the transfer, and then the third step (S3) to determine whether the transfer is successful, and as a result of the determination the transfer is successful and the network management through the node management assembly (3-2) A fourth step (S4) of informing the system 1 of the transfer operation success, and if it fails, also notifying the network management system 1 of the failure, and controlling the transfer operation by the operator;

In the network management system 1 through the step S4, the partner node-to-node connection assembly 3-3 connected to the node-to-node connection assembly 2-1-1 that performed the transfer after receiving the success message has been received. A fifth step (S5) of instructing 1-1) to perform a transfer; The node-to-node connection assembly 3-1-1 that has received the protection switching command in step S5 receives the node-to-node connection assembly 3-1-1 that is currently in the active state. A sixth step (S6) of determining whether or not the success thereof is performed after the replacement operation is performed in -1-2); And

If the determination resulted in a successful transfer, the node management assembly 3-2 notifies the network management system 1 of the successful transfer, and if it fails, it notifies the network management system 1 of the failure and the cause thereof. By performing the transfer control by the operator, the operation is sequentially performed in the seventh step S7 of completing the transfer process.

At this time, there are three types of errors declared in the first step (S1), the first of which is a Loss Of Signal (LOS) state indicating loss of an input signal. The second signal is a LOF (Loss Of Frame) state that indicates a frame loss condition. The second signal is declared when an Out Of Frame (OOF) state lasts for 3ms in the input signal.The third signal is a LOC (Los Of Of) signal. Cell Delineation) Declares when an error header is detected in 7 or more consecutive cells.

When the above error occurs, the second step (S2) of notifying error detection to the inter-node connection assembly (3-1-1) is 'K2' in the STM-1 frame transmitted through the STM-1 link. The error detection is notified by setting the byte 6, 7, 8 bits to 110 and transmitting.

Through the above process, the error is detected and recovered so that the subscriber can be provided with continuous service.

For reference, as shown in FIG. 2 (c) of FIG. 2 (c) which schematically illustrates the ATM traffic flow changed during the underfloor process when an error occurs on the link as described above, an active node-to-node connection assembly that detects that a link failure has occurred ( 2-1-1) notifies the standby standby inter-node connection assembly (2-1-2) of the failure so that it can pass the received ATM traffic without terminating, and transmits the failure since it occurred on the receiving link. Traffic is normally sent to the active node-to-node connection assembly 3-1-1, which is the other node.

This means that only the failed traffic is terminated and transferred, and the non-failed traffic is used normally.

(The bold solid line shown in the drawing indicates traffic flow, '■' indicates end of traffic, and 'x' indicates where a failure occurred.)

In addition, when the error occurs in the connection assembly itself between the two types of error occurs, the process of recovering the error is as shown in FIG. 3 (a) and FIG. 3 (b). a) indicates that an error (x) has occurred in the inter-node connection assembly 2-1-1 that is currently active.

The current in the node-to-node assembly 2-1-1 indicates a state in which normal operation is impossible due to a hardware error, a device failure, or a partial power failure of the assembly. The process of doing this will be described with reference to the flowchart shown in FIG. 3 (b).

If an error occurs in the inter-node connection assembly 2-1-1 that is active while all the systems are operating in a normal state, the spare assembly 2- of the inter-node connection assembly 2-1-1 in which the error has occurred In step 1-2, a first step T10 of detecting the same, and an active node-to-node connection assembly 3-1-1, which is a pair of node-to-node connection assemblies 2-1-1 that have errors at the same time as the step T10, are detected. A second step (T20) of detecting that an error has occurred in the opposite party through the input of an abnormal signal in 1); After performing the first step T10, the standby node-to-node connection assembly 2-1-2 that detects an error occurrence is notified to the network management system 1 of the error occurrence, and then the node-to-node connection assembly 2 in an active state. -1-1) and a third step (T11) performing a transfer (within 50 ms) and an active node-to-node connection assembly (3-1-1) that detects an error after performing the second step (T20). A fourth step T21 of notifying the network management system 1 of the occurrence of an error and then performing a transition (executed within 50 ms) with the inter-node connection assembly 3-1-2; After performing the above steps (T10, 11, 20, 21), it is determined whether the transfer is successfully performed, and if the transfer is successful, through the node management assemblies 2-2 and 3-2. The network management system 1 is notified of the success of the transfer operation, and if it fails, the network management system 1 is also notified of the failure, and then the operation is sequentially performed in a fifth step T30 for controlling the transfer operation by the operator.

At this time, the first, third steps (T10, T11), and the second, fourth steps (T20, T21), as shown in the figure, if an error occurs at the same time independently performed at each node system at the same time, after the transfer The success determination and subsequent execution, that is, the task corresponding to the fifth step (T30), are also tasks that are independently performed in each system (the same processing of tasks performed by the two systems at the same time is simply performed to simplify the drawing. Shown).

All recovery situations and completion of recovery are notified to the network management system 1 and each node management assembly 2-1, 2-2, and 3-2. The time for recovering all errors through the above process is As a very short time, the subscriber hardly feels disconnected.

For reference, in the case where an error occurs in the active node-to-node connection assembly 2-1-1 as described above, the traffic flow of the ATM which is changed during the switching process is schematically illustrated in FIG. The standby inter-node connection assembly 2-1-2 that detects that a failure has occurred in the inter-connection assembly 2-1-1 has switched to an active state, and then the standby inter-node connection assembly 3-1-2 of the partner node. Pass ATM traffic received from 2) without terminating it.

In addition, the active node-to-node connection assembly 3-1-1, which cannot receive a normal signal due to the failed node-to-node connection assembly 2-1-1, detects a failure of the received signal and detects a standby node-to-node connection assembly ( 3-12-2) to perform normal traffic processing.

That is, since the failure of the inter-node connection assembly occurs, all the traffic packs are also transferred according to the transfer of the inter-node connection assembly in the active state.

(The bold solid line shown in the figure indicates traffic flow, '■' indicates the end of the traffic, and 'x' indicates the location of the failure.)

As described in detail above, the present invention processes the node-to-node connection assembly of the ATM-MSS in a redundant structure, and detects errors in the node-to-node connection assembly and errors on the link, thereby automatically recovering them, thereby providing continuous service support to the subscriber. This has the advantage of improving the reliability of the system.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the following claims You will have to look.

Claims (2)

Duplicating the internode connection assembly with the internode connection assembly in an active state and a standby state; Detecting an error occurring during the operation of the system in the dual ring state; If it is detected that an error has occurred in a link between active node-to-node connection assemblies during the error detection, notifying the node-to-node connection assembly, network management and system of an error in the active node-to-node connection assembly; The node-to-node connection assembly notifying the occurrence of an error transfers the currently active node-to-node connection assembly to the node-to-node connection assembly and notifies the network management system of the transfer, and the network management system receives the transfer completion message. Instructing a node-to-node connection assembly connected to the node-to-node connection assembly that performed the transfer, and the node-to-node connection assembly receiving the command to perform a transfer and notify the network management system thereof. Recovering the error through; If an error occurs in an active node-to-node connection assembly during the error detection, detecting an error occurrence in a standby node-to-node connection assembly of the node-to-node connection assembly in which the error occurs and notifying the network management system of the error occurrence; And at the same time, detecting an error occurrence through abnormal reception data in the active node-to-node connection assembly of the node-to-node connection assembly in which the error occurred, and notifying the network management system of the error occurrence, and the node having the error following the notification. On the system side, the node-to-node connection assembly is switched to the active state, and on the state side, the node system that has an error transfers the active node-to-node connection assembly to the network management system after the standby state is transferred to the node-to-node connection assembly. Steps Recovering the error through; Asynchronous transmission mode information communication network switching system (ATM-MSS) node-to-node connection assembly (NIA) redundancy control method comprising a. 2. The method of claim 1, wherein the received data on the link is to receive both active / standby node-to-node connection assemblies so that the error of the redundant internode connection assembly can be automatically recovered. A method of dual node connection assembly (NIA) between asynchronous transmission mode type information network switching system (ATM-MSS), characterized in that only the node-to-node connection assembly is enabled.