KR0152229B1 - Low price duplication node - Google Patents

Abstract

The present invention relates to a low-cost duplication node for duplication of a system, comprising: a selection control circuit 30 outputting a selection signal for selecting one of two received data; Selection means (31) for selecting one of two input data by a selection signal; The physical link matching device means 32 which receives the output of the selecting means 31, extracts and outputs a clock and data, outputs the input data to two nodes, and outputs a transmission / reception alarm display signal when an error of transmission / reception data occurs. ); Data processing means (33) for classifying, exchanging and inputting the input data; Control means 35 for periodically outputting a node function status signal to a corresponding node, outputting a specific pattern signal of its own node, and generating and outputting an active request control signal; Function monitoring means (36) for outputting a corresponding node malfunction indication signal and a failure indication signal of its own node; State signal generating means 37 for determining a state of the node and outputting a node state display signal; And a line fault identification means 34 for outputting a line status indication signal to a corresponding node. The system automatically replaces a waiting normal part when a failure occurs in a part of a system in operation by applying a cyclic automatic switching method to an ATM switching system. This increases the reliability and reduces the price and size of the ATM switching system by reducing the number of physical link matching elements to half.

Description

Low cost redundancy node for system redundancy

1 is a diagram illustrating a redundancy model for a cell delivery path of a typical system.

2 is a redundant configuration diagram of a conventional system.

3 is a redundant configuration diagram of a system to which the present invention is applied.

4 is a state transition diagram of a redundant system to which the present invention is applied.

5 is a block diagram of a redundant node according to an embodiment of the present invention.

6 is a state transition diagram of a state signal generation circuit according to an embodiment of the present invention.

7 is a truth table of a selection control circuit according to an embodiment of the present invention.

8 is a block diagram of a line failure identification circuit according to an embodiment of the present invention.

9 is a state transition diagram of a reception failure circuit in one embodiment of the present invention.

10 is a state transition diagram of a transmission failure circuit according to an embodiment of the present invention.

11 is an exemplary view of a duplication method using the present invention.

* Explanation of symbols for main parts of the drawings

30,39: Selection control circuit 31,40: Selector

32,38: physical link matching element 33: data processing unit

34: circuit failure identification circuit 35: control unit

36: function monitoring circuit 37: status signal generating circuit

The present invention relates to a low cost redundant node for system redundancy.

Redundancy is a method of increasing the reliability of a system by automatically replacing the waiting part when a failure occurs in a part of the system in operation. In an ATM switching system, an ATM cell has a transmission path through several modules to be delivered to a desired subscriber. The part of this path that requires high reliability is composed of redundancy. The redundancy module minimizes data loss by quickly replacing a spare module when a normal data transfer path fails. ATM switching system consists of a combination of several modules, which send and receive high-speed data. The high speed data between modules is transmitted as low speed parallel data or high speed serial data. When the distance between modules is large or a large number of signal lines are used, a high speed serial data transmission method using a small number of signal lines is used rather than a low speed parallel data transmission method. In most serial data transmission methods, a physical link having a common protocol is used. Since these physical links process high-speed data, expensive devices are used. In a redundant structure, these devices take four sets per module. Therefore, the conventional redundancy system has an expensive problem by using one physical link matching element per transmission / reception link.

The present invention devised to solve the problems of the prior art as described above provides a low-cost redundancy node for redundancy of the system that can configure a redundancy system at a low cost by using one physical link matching element per two transmission and reception links. Its purpose is to.

The present invention for achieving the above object is a selection control means for receiving a node status indication signal from two nodes to generate and output a selection signal for selecting one of the two received data; Selection means for receiving received data from two nodes and selecting one of two input data according to a selection signal of said selection control means and outputting it; Receives the output of the selection means, extracts and outputs the clock and data, receives the processed data, outputs the transmission data to two nodes, and receives when an error occurs in the received data input from the selection means. Physical link matching element means for outputting an alarm indication signal and outputting a transmission alarm indication signal when an error occurs in transmission data; Data processing means for receiving the output of the physical link matching device means, classifying and exchanging the input data to output the physical link matching device means; It outputs node function status signal to transmit corresponding pattern periodically to corresponding node, outputs specific specific pattern signal generated from its own node, and active request for controlling transition from inactive state to active state. Control means for generating and outputting a control signal; Monitor the promised specific pattern signal transmitted from the corresponding node and if no signal is detected for a predetermined time t ₁ , output the corresponding node malfunction indication signal, and monitor the self-node specific pattern signal of the control means for a predetermined time ( function monitoring means for outputting a malfunction indication signal by the own node if no signal is detected during t ₁ ); A node failure signal and a node status indication signal are input from a corresponding node, and a corresponding node failure indication signal, a self node failure indication signal, and an active request control signal are input from the control means. Status signal generating means for determining a status and outputting a node status display signal; And a line fault identification means for receiving a reception alarm display signal and a transmission alarm display signal from the physical link matching device means, receiving a node status display signal from the status signal generating circuit, and outputting a line status display signal to a corresponding node. Characterized in that provided.

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

First, the definition of the terms used in the present invention will be described.

Node: The interior of an ATM switching system consists of several modules, which are called nodes.

Single node: A node that is not redundant.

Dual Nodes: Two nodes that process the same data at the same time. Dual nodes are divided into active nodes and spare nodes.

Corresponding node: Used when dual nodes refer to each other. By way of example, the corresponding node of an active node is a spare node.

Connection Node: A neighboring node that transmits and receives an ATM cell.

Active node: In a dual node, a node that is a data node and a connection node. The corresponding node is a spare node.

Reserved Node: A node corresponding to an active node. If the active node fails, the spare node is converted to the active node.

Active state: Indicates the state of the active node.

Inactive state: Indicates the state of the spare node.

Function failure: Declares when a hardware failure including power failure, hernia, and CPU continues for a certain amount of time (t ₁ ).

Local alarm: Declared when there is a failure in the received data due to cable hernia, poor performance target, and line failure.

Remote alarm: Declared when a failure occurs in the transmission data due to the failure of the cable sheath performance target and the line failure.

Local Failure (LF): Declared when the incoming alarm lasts for a certain time (t ₂ ).

Remote Failure (RF): Declared when the transmission alarm lasts for a certain time (t ₃ ).

Link failure: Declared when the incoming and outgoing alarms on the link between link nodes last for a certain time. There are two types of track failures: reception failure and transmission failure.

1 is an explanatory diagram for explaining a duplication module for a cell delivery path of a general system.

The inside of the ATM switching system is composed of several modules connected to each other. These modules are divided into a single node and a dual node as shown in FIG. The dual nodes monitor the occurrence of the failure of the corresponding node, and in case of failure, the active node switches to the spare node and the spare node switches to the active node. Automatic switching refers to a method in which a normal node becomes active when a malfunction occurs and automatically detects a normal path when a line failure occurs.

2 shows a configuration diagram for redundancy of a conventional system.

The node is composed of a physical link matching device 10, a selector 11, and a data processing unit 12, the physical link matching device 10 converts the data received from the selector 11 into a protocol of a promise type The data is transmitted to the corresponding node or the protocol is processed in the signal received from the corresponding node, and only pure data is delivered to the selector 11.

The selector 11 transfers the data transferred from the data processing unit 12 to the two physical link matching elements 10, and selects one of the data transferred from the two physical link matching elements 10 to the data processing unit 12. To pass.

The data processing unit 12 processes the received data and delivers it to the selector 11.

In the conventional redundant system as described above, since the monitoring of all connection nodes is performed at the same time by using one physical link matching device 10 per transmission link, the physical link matching device can be easily found if a failure occurs in the line. There is a problem that the cost is expensive to configure the system because it is expensive.

3 is a redundant configuration diagram of a system to which the present invention is applied.

The components of the nodes are similar to the prior art, but the position of the selector 25 is placed in front of the physical link matching element 26 to reduce the number of physical link matching elements 26. Since each node has one physical link matching element 26 per transmission and reception link, it is impossible to monitor all the lines at the same time. Therefore, when a track failure occurs, it is necessary to find a normal path by connecting with the connecting nodes sequentially until a normal track is found. For this sequential connection, a status signal signal line between the connection nodes is additionally required while classifying the failures and different failure declaration points. Therefore, in the redundant system using the present invention, a status signal signal line must be added between the connection nodes instead of reducing the number of physical link matching elements 26 by half compared to the existing redundant system.

4 shows a state transition diagram of a redundant system to which the present invention is applied.

The spare node of the redundant system using the cyclic automatic switching method monitors the state of the active node, transitions to the active state, and notifies the active node. The active node transitions to the inactive state after confirming that the spare node has transitioned to the active state. In addition, by the user's mandatory designation, the spare node becomes an active node and the active node becomes a spare node.

When a node transitions from an inactive state to an active state, the corresponding node's failure states are malfunction, transmit and receive. Malfunctions are declared when power failure, hernia, and hardware failure occur at the active node, causing abnormal operation for a certain time (t ₁ ). A reception failure is declared if an error occurs in the data received at the connection node for a predetermined time t ₂ , and a transmission failure is declared if an error persists for a predetermined time t ₃ in the data transmitted to the connection node. This fault declaration is declared when faults occur continuously for a certain period of time, and the time used in each fault is related to t ₁ t ₂ t ₃ , 2 t ₁ t ₂ , 2 t ₂ t ₃ . Therefore, if a failure occurs, the normal path and node can be found by searching several paths with appropriate nodes. Therefore, the cyclic automatic switching method is a duplication method that connects all nodes sequentially to find a normal node and prevents data loss when a failure occurs.

5 is a block diagram of a redundant node according to an embodiment of the present invention, wherein 30 and 39 are selection control circuits, 31 and 40 are selectors, 32 and 38 are physical link matching elements, 33 are data processing units, and 34 are shown in FIG. Denotes a line fault identification circuit, 35 denotes a control unit, 36 denotes a function monitoring circuit, and 37 denotes a state signal generating circuit.

The selection control circuit 30 receives a status signal STS1 at the node 1 and a status signal STS2 at the node 2, and selects a signal SEL for selecting one of two received data TX1 and TX2. ) Is generated and output to the selector 31.

The selector 31 receives the reception data TX1 at the node 1 and the reception data TX2 at the node 2, and selects one data from two input data by the selection signal SEL of the selection control circuit 30. Select to transfer to the physical link matching device (32).

The physical link matching device 32 extracts a clock and data from the signal input from the selector 31 and outputs the clock and data to the data processor 33 or receives the data processed by the data processor 33 and receives the node 1 and the node 1. The transmission data TX3 is output to the node 2. If an error occurs in the reception data RX input from the selector 31, a reception alarm is declared to output the reception alarm display signal LA1 to the line failure identification circuit 34, and the transmitted data TX3. If an error occurs, a transmission alarm is declared and the transmission alarm display signal RA1 is output to the line failure identification circuit 34.

The controller 35 periodically outputs the functional state FF3 of the node to the corresponding node in order to deliver a constant pattern to the corresponding node, and outputs the specific specific pattern signal FF1 generated in its own node to the function monitoring circuit 36. Output to In addition, an active request control signal ACT for generating a transition from the inactive state to the active state is generated and transmitted to the state signal generation circuit 37.

The function monitoring circuit 36 monitors the specified specific pattern signal FF4 transmitted from the corresponding node, and if there is no signal detected for a predetermined time t ₁ , declares a functional failure of the corresponding node to indicate a corresponding node malfunction indication signal. (FFR) is output to the state signal generation circuit 37. Then, if the specific specific signal signal FF1 generated from the own node is monitored, and if no signal is detected for a predetermined time t ₁ , the function failure of the own node is declared and the self-node malfunction display signal FFL is displayed. Output to the signal generating circuit 37.

The status signal generating circuit 37 is a line failure signal RLF4 and a node status display signal STS4 from the corresponding node, and a corresponding node failure display signal FRR and its own node function from the function monitoring circuit 36. A failure indication signal FFL and an active request control signal ACT are input from the control unit 35 to determine the state of the node, and the node state indication signals STS3 and STS3B are connected to the associated node and the line failure identification circuit 34. )

The line failure identification circuit 34 receives the reception alarm display signals LA1 and LA2 and the transmission alarm display signals RA1 and RA2 from the physical link matching elements 32 and 38, and the state signal generation circuit 37 In response to the node status indication signal STS3B, the line status indication signal RLF3 is transmitted to the corresponding node. The data processor 33 classifies and exchanges data input from the physical link matching elements 32 and 38 and outputs the data to the physical link matching elements 32 and 38.

The selector 40 receives the received data TX5 received at the node 5 and the received data TX6 received at the node 6 and selects one from two input data by the selection signal SEL of the selection control circuit 39. It selects and transfers it to the physical link matching element 38.

The selection control circuit 39 receives the node status display signal STS5 at the node 5 and the node status display signal STS6 at the node 6, and selects one of two reception data TX5 and TX6. SEL) is generated and output to the selector 40.

The physical link matching device 38 extracts a clock and data from the data RX input from the selector 40 and transfers the clock and data to the data processor 33 or receives the data processed by the data processor 33 and receives a node. Output data TX3 to node 5 and node 6. In addition, when an error occurs in the received data RX received from the selector 40, a receiving alarm is declared to output the receiving alarm display signal LA2 to the line failure identification circuit 34, and the transmitted data ( If an error occurs in TX3), a transmission alarm is declared and the transmission alarm display signal RA2 is output to the line failure identification circuit 34.

The state signal generating circuit 37 receives the state information of the corresponding node and the state information of its own node, determines whether it is active or inactive, and transfers the same to the connection node and the corresponding node.

6 is a state transition diagram of a state signal generation circuit according to an embodiment of the present invention, which is transitioned by a system clock.

The status signal generation circuit 37 receives the active request control signal ACT, the function failure display signal FFL of the corresponding node, the status display signal STS4 of the corresponding node, and the line failure display signal RLF of the corresponding node. To output the node status display signals STS3 and STS3B. The node status display signal STS3 outputted to the adjacent node is a signal one clock phase ahead of the node status display signal STS3B input to the line fault identification circuit 34, and is required to initialize to a normal state when the node status transitions. Do. This initialization is necessary for the transition to occur at least a predetermined time (t ₂ ) after the node state transitions due to line failure. The state transition of the dual node transitions from the active state to the inactive state after the spare node is changed from the inactive state to the active state. The conditions for transitioning from the inactive state to the active state are as follows.

On activation request by control unit

When the node status is normal and a malfunction occurs in the corresponding node.

-When the node status is normal and line failure occurs in the corresponding node

The conditions for transitioning from the active state to the inactive state are as follows.

When the spare node transitions from inactive to active

7 shows a truth table of the selection control circuit according to an embodiment of the present invention.

The selection control circuit 30 outputs a selection signal SEL for selecting one of the data TX1 and TX2 received from the two nodes using the node status display signals STS1 and STS2 provided from the connection node. Since the node status display signals STS1 and STS2 of two nodes are not simultaneously converted, both nodes may exist in an active state at any particular moment. Therefore, the selection control circuit 30 outputs the next state in synchronization with the system clock when one of the two signals STS1 and STS2 showing the state of the node changes.

In the drawing, if the state of STS1 and STS2 is 0, the connection node is in an active state, and if it is 1, it is inactive. If the output SEL signal is 0, TX1 of the connection node is selected, and if 1, TX2 is selected.

8 is a block diagram of a line failure identification circuit according to an embodiment of the present invention.

The line fault identification circuit 34 delivers the line state information RLF3 to the corresponding node in an inactive state and provides information for transitioning to the active state.

The line fault identification circuit 34 receives a first logical sum gate 41 and a physical link matching element 32 and 38 that receive and logically output the transmission alarm display signals RA1 and RA2 from the physical link matching elements 32 and 38. The second logical sum gate 42 which receives the reception alarm display signals LA1 and LA2 and outputs the logic sum and outputs it, and the output RA of the first logical sum gate 41 are received, and the state signal generation circuit 37 A transmission failure signal generation circuit 43 for receiving a node status indication signal STS3B in a current state and outputting a transmission failure indication signal RF from a node status indication signal in a previous state, the second logic gate ( 42, the output LA is inputted, and the node status display signal STS3B of the current state is received from the state signal generation circuit 37, and compared with the node status display signal of the previous state. A reception failure signal generation circuit 44 for outputting the transmission failure signal generation circuit 43 and Consists of a group received, error signal generation exclusive OR gate 45, which outputs a logical OR receives the output of the circuit 44.

9 is a state transition diagram of a reception failure circuit according to an embodiment of the present invention. When an error occurs in a reception data for a predetermined time t ₂ in a normal state, the state transitions to a reception failure state, and a predetermined time ( Receive normal data during t ₂ ) or return to normal when node state transitions from inactive state to active state, or when node state transitions from active state to inactive state.

10 is a state transition diagram of a transmission failure circuit according to an embodiment of the present invention. When an error occurs in transmission data for a predetermined time t ₃ in a normal state, the transmission transitions to a transmission failure state, and a predetermined time in a transmission failure state. Normal data is sent during (t ₃ ), or when the node state transitions from the inactive state to the active state, or when the node state transitions from the active state to the inactive state.

11 shows an exemplary view of a duplication method using the present invention. Referring to Fig. 11, how cyclic automatic switchover is performed in the case of a failure in the redundancy module of the ATM switching system, where node 1 and node 3 are active nodes, the solid line transfers data and status information between the active nodes. Display.

1) In case of malfunction at node 3

(1) When node 4 (the spare node) receives the abnormal state for a predetermined time t ₁ from the functional state indication signal FF3, it determines node 3 as a malfunction and switches to the active state.

(2) The node 3 in the normal state confirms that the node 4 transitions from the inactive state to the active state and then transitions from the active state to the inactive state. Therefore, node 1 and node 4 become active nodes.

2) In case of failure in line A

(1) Node 1 (active node) declares a line failure by receiving alarm if the failure in line A persists for a certain time t ₂ . Then, the line failure indication signal RLF1 is transmitted to the node 2.

(2) Node 2 receives the line fault indication signal RLF1 from Node 1 and transitions to the active state.

(3) Node 1 confirms that Node 2 transitions to the active state and transitions from the active state to the inactive state. Thus, node 2 and node 3 become active nodes.

3) In case of failures in lines A and B

(1) Node 1 (Active Node) sends a transmission alert to Node 3 and Node 4 when Line A fails. In addition, if the fault in line A persists for a certain time (t ₂ ), the line failure is declared by the reception alarm. Then, the line failure indication signal RLF1 is transmitted to the node 2.

(2) Node 2 receives the line failure from Node 1 and transitions to the active state.

(3) Node 1 confirms that Node 2 transitions to the active state and transitions from the active state to the inactive state. However, due to line failure B, node 2 sends a transmission alert to node 3 and node 4.

(4) When node 3 (the active node) receives the transmission alarm from node 1 for a predetermined time t ₃ , it declares a line failure and transmits a line failure indication signal RLF3 to node 4.

(5) Node 4 receives the line failure from Node 3 and transitions to the active state.

(6) Node 3 confirms that Node 4 transitions to the active state and transitions from the active state to the inactive state. Thus, nodes 2 and 4 become active nodes.

According to the present invention configured as described above, if a failure occurs in a part of a system in operation by applying a cyclic automatic switching method to an ATM switching system, the standby part is automatically replaced to increase reliability and increase the number of physical link matching elements. In half, the price and size of ATM switching systems are reduced.

Claims (4)

Selection control means (30) for receiving a node status indication signal from two nodes to generate and output a selection signal for selecting one of two received data; Selection means (31) for receiving received data from two nodes and selecting and outputting one of two input data according to a selection signal of the selection control means (30); Receives the output of the selection means 31, extracts and outputs the clock and data, receives the processed data, outputs the transmission data to the two nodes, and also receives the received data input from the selection means 31. A physical link matching element means 32 for outputting a reception alarm display signal when an error occurs, outputting a transmission alarm display signal when an error occurs in the transmission data, and outputting a transmission alarm display signal when an error occurs in the transmission data; Data processing means (33) for receiving the output of the physical link matching element means (32) to classify and exchange the input data and to output the physical link matching element means (32); It outputs node function status signal to transmit corresponding pattern periodically to corresponding node, outputs specific specific pattern signal generated from its own node, and active request for controlling transition from inactive state to active state. Control means 35 for generating and outputting a control signal; By monitoring the promised specific pattern signal transmitted from the corresponding node, if no signal is detected for a predetermined time t ₁ , the corresponding node malfunction indication signal is output, and the self-node specific pattern signal of the control means 35 is monitored. Possible monitoring means (36) for self-node outputting a malfunction indication signal if no signal is detected for a predetermined time (t ₁ ); The line failure signal and the node status indication signal are input from the corresponding node, and the corresponding node malfunction indication signal and the self node failure indication signal are received from the function monitoring means 36, and the active request control is performed by the control means 35. State signal generating means (37) for receiving a signal to determine the state of the node and outputting a node state display signal; And receiving a receiving alarm display signal and a transmitting alarm display signal from the physical link matching device means 32, and receiving a node status display signal from the status signal generating circuit 37 and outputting a line status display signal to a corresponding node. Low cost redundancy node for redundancy of the system, characterized in that it comprises a line failure identification means (34). 2. The apparatus as claimed in claim 1, further comprising: second selection control means (39) for receiving a node status indication signal from two nodes in different directions and generating and outputting a selection signal for selecting one of two received data; Second selection means (40) for receiving received data from two nodes in different directions and selecting and outputting one of two input data according to a selection signal of the second selection control means (39); Receives the output of the second selection means 40, extracts and outputs the clock and data, receives the processed data and outputs the transmission data to two nodes in different directions, and further, the second selection means 40 And a second physical link matching element means 38 for outputting a reception alarm indication signal when an error occurs in the received data inputted from the subfield, and outputting a transmission alarm indication signal when an error occurs in the transmission data. Low cost redundancy node for system redundancy. The first logic gate means according to claim 1 or 2, wherein the line fault identification means (34) receives and outputs the logical signal of the transmission alarm indication signal from the two physical link matching element means (32, 38). (41); Second logical sum gate means (42) for receiving and alarming the received alarm display signal from the two physical link matching device means (32, 38); Receiving the output of the first logic gate means 41, receiving the current node status display signal from the status signal generating means 37, and outputting a transmission failure display signal in comparison with the previous node status display signal; Transmission failure signal generating means 43; Receiving the output of the second logic gate means 42, receiving the current node status indication signal from the status signal generating means 37, and outputting a reception failure display signal in comparison with the previous node status indication signal; Reception failure signal generating means 44; And a logic sum gate means 45 which receives the output of the transmission failure signal generating means 43 and the output of the reception failure signal generating means 44 and logically sums the outputs. . 2. The node status indication signal according to claim 1, wherein the status signal generating means 37 outputs the node status indication signal output to the adjacent node identification means 34 to initialize the node state to a normal state when the node status transitions. Inexpensive redundancy node for system redundancy, characterized by faster output by one clock phase.