JP2006261980A - Network connection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network connection device capable of stably executing redundant switching processing. <P>SOLUTION: A time division multiplex bus (PCM HWY) is shared by an active system substrate and a standby system substrate. That is, all of the time division multiplex buses connected to the active system substrates 10A1-10Am are connected to the standby system substrate 10S as well. All of the time division multiplex buses connected to the active system substrates 20A1-20An are connected to the standby system substrate 20S as well. Then, at the time of the redundant switching processing, the standby system substrate itself selects the time slot of the active system substrate to be a switching origin. Thus, redundant switching is performed without switching a time division multiplex internal bus or a time slot, and thus the redundant switching processing is stably executed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a network connection device used for connecting, for example, a circuit switching network and an IP (Internet Protocol) network. In particular, the present invention relates to a network connection apparatus that has a single protection line for a plurality of operation lines and has a function of performing N + 1 protection switching within the apparatus.

  In recent years, information communication services including voice and data communication have been diversified as information communication needs have increased and communication has been liberalized. Against this background, the number of operators (carriers) newly entering the communication service field has increased, and service competition between carriers has become active. The new carrier is referred to as NCC (New common carrier), and provides various services using technologies such as VoIP (Voice over Internet Protocol). VoIP is a technology that integrates a voice network and a data network by packetizing and transmitting digital voice data.

  NCCs often borrow equipment such as an exchange from a specific carrier that already has a subscriber line at a predetermined charge. Many NCCs build their own exchange networks such as IP networks with their own funds. In addition, a communication system is formed by adding a circuit switching network (PSTN: Public Switched Telephone Network) of a specific carrier, and these facilities are used in combination for providing services to general users.

  In the existing communication system, the NCC exchange network is located on the network side from the exchange as viewed from the user. That is, a call originated from a user terminal first reaches the PSTN exchange via the subscriber line, and is then sent from the exchange to either the PSTN or the exchange network. In other words, the NCC arranges its own switching network after the exchange of the specific carrier and constructs its own communication system.

  In order to construct a communication system combining a PSTN and an IP network, a network connection device such as a gateway device is used. This type of apparatus includes an IP conversion unit that converts voice data and binary data into IP (Internet Protocol) packets, a packet switch unit that switches IP packets, and various interfaces.

By the way, this type of apparatus often includes an N + 1 preliminary switching mechanism (see, for example, Patent Document 1). In performing the N + 1 preliminary switching, the existing device physically switches the time slot and the internal bus. However, in this system, when a failure occurs in the time switch or the control unit and the redundant switching is performed, the switching control of the time slot and the bus is necessary even at the switching destination. In addition, when information cannot be transferred between the active system and the standby system, there is a problem in that N + 1 switching is switched back and switching setting takes time. Furthermore, an automated system is required to always be able to perform the same operation without depending on the N + 1 switching state, but there is a contradiction that an operator performs an operation on a physical operation system.
JP 2001-217844 A

As described above, in the existing network connection device, there is a problem in that N + 1 switching is switched back and switching setting takes time. Furthermore, an automated system is required to always be able to perform the same operation without depending on the N + 1 switching state, but there is a contradiction that an operator performs an operation on a physical operation system.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a network connection device capable of stably performing a redundancy switching process.

  In order to achieve the above object, according to one aspect of the present invention, a line interface unit that converts a transmission signal introduced from a plurality of communication networks into a time-division multiplexed signal and a circuit-switching of the time-division multiplexed signal are performed. A switching unit that leads to the line interface and interconnects the plurality of communication networks; and a time division multiplex bus that connects the line interface unit and the switching unit. A plurality of operational boards connected to each of the multiple buses; a standby board that is connected to each of the plurality of operational boards and is connected to a time-division multiplex bus and forms an N + 1 redundancy system with the plurality of operational boards; In the redundant switching process between the active system board and the standby system board, the standby system board accesses the same time slot as the switching source active system board. Network connection device is provided, characterized in that it comprises a switching means for switching the time division multiplexing bus in order to.

  By taking such a measure, the time division multiplex bus can be shared by the operation system board and the standby system board. That is, any of the time division multiplex buses connected to the plurality of operation system boards is also connected to the standby system board. In the redundancy switching process, the standby system board selects the time slot of the active system board that is the switching source. As a result, redundancy switching can be performed without switching the time-division multiplexed internal bus or time slot, and therefore the redundancy switching process can be stably performed.

  According to the present invention, it is possible to provide a network connection device capable of stably performing a redundancy switching process.

  FIG. 1 is a functional block diagram showing an embodiment of a network connection apparatus according to the present invention. 1 includes an A network interface (I / F) unit, a B network I / F unit, a control switch unit 80 (80-0, 80-1), and a maintenance line interface unit 50. .

  Among these, the A network I / F unit includes the operation system boards 10A1 to 10Am and the standby system board 10S, and forms an N + 1 redundant system. Similarly, the B network I / F unit includes operation system boards 20A1 to 20An and a standby system board 20S, and forms an N + 1 redundant system. All of these boards are connected to the control switch unit 80 (80-0, 80-1) via a time division multiplex bus (PCM HWY). The control switch unit 80 is duplicated into an active system and a standby system, of which 80-80 is assigned to the active system (ACT) and 80-1 is assigned to the standby system (SBY).

  The A network I / F unit and the B network I / F unit are connected to different information communication networks (differentiated as A network and B network). An example of the A network is a subscriber line network of a wireless communication system, and an example of the B network is a circuit switching network. This network connection device performs protocol conversion for information communication between networks, and is realized as a gateway device or the like. The maintenance line I / F unit 50 is connected to a system monitoring control device (not shown) or the like via the maintenance line.

  The A network I / F unit and the B network I / F unit terminate data received from the respective networks, and send voice data to the control switch unit 80 (80-0, 80-1) via the PCM highway (PCM HWY). ). Both the active system control switch unit 80-0 and the standby system control switch unit 80-1 are mounted on individual hardware boards and have the same configuration.

  The control switch unit 80 exchanges time-sharing data on the PCM highway with a central control unit 90 that mainly controls the A network I / F unit 10, the B network I / F unit 20, and the maintenance line I / F unit 50. A switch unit 100 to be connected and a memory 110 for storing control data 110a necessary for processing of the central control unit 90 are provided. The central control unit 90 includes a switching processing unit 90a that performs processing related to redundancy switching.

  By the way, each of the standby substrates 10S and 20S includes an access control unit 30. The access control unit 30 switches the time division multiplex bus (PCM HWY) in order to access the same time slot as the switching-source operation system board in the redundancy switching process with the operation system board. The control switch units 80-0 and 80-1 operate independently, and can perform switching independently when a failure occurs, and can be switched by a remote operation from the monitoring control device.

  In the above configuration, at the time of N + 1 preliminary switching, switching of the time division multiplex bus is performed so that the operation system board stops access to the internal bus and the standby system board accesses the same time slot. As a result, even if the operating system is switched from the control switch unit 80-0 to the control switch unit 80-1, the control / switch unit 80 does not need to control the N + 1 preliminary switching state of the switch unit 100, thereby simplifying the processing. It becomes possible. Accordingly, it is possible to stabilize the redundancy switching process.

FIG. 2 is a state transition diagram of N + 1 preliminary switching in this embodiment. Switching / switchback is executed while transitioning between these states by failure / recovery events that occur on the active system board and standby system board and command switching / switchback that is instructed by the monitoring control device.
FIG. 3 shows the state transition of the Lock Out command due to the substrate blockage. While changing the state according to the command block state of the active system board and the standby system board, the switchable / unswitchable state is entered. The state transition shown in FIG. 2 shows a case where switching is possible, but when switching is impossible, switching is prohibited, so that state transition is caused by an occurrence / recovery event of a failure during IDLE or switching.

  FIG. 4 is a flowchart showing a processing procedure in N + 1 preliminary switching. For example, when a command block instruction is issued from the monitoring control device to an arbitrary line of the network connection device, it is first determined whether the request source is an operator or automatic control such as data setting (step S1). If the requesting source is an operator, the command board is blocked from the operation board line or the standby board line depending on the accommodation position of the command block line (step S2).

  In the case of automatic control, it is determined whether or not the N + 1 preliminary switching state is being switched (step S4). If it is not being switched, the command line is blocked on the active board line (step S3), and if it is being switched, the command line is blocked on the standby board line (step S5). By doing so, the operator operates the physical accommodation position of the line while looking at the screen of the supervisory control device, and inputs the command without knowing the N + 1 switching state in the automatic control. It becomes possible.

  FIG. 5 is a diagram illustrating an example of a node management screen. As shown in FIG. 5, in this embodiment, the boards mounted on the network connection apparatus are graphically displayed in a list, and the color of the board is changed according to the occurrence of a failure and the N + 1 preliminary switching state to indicate the state to the operator. In this screen, priorities are assigned in the order of command blockage, N + 1 standby switching state, failure state, and normal in the operation system board, and each board is color-coded and displayed in the color of the event with the highest order. In the standby system board (non-switching state), priorities are given in the order of command blockage, failure state, and N + 1 preliminary switching. In FIG. 5, the state of color coding is shown by hatching.

  FIG. 6 is an example of a screen for executing N + 1 preliminary switching from the monitoring control device side. To confirm the status of the standby system board (failure, N + 1 switching status) on the circuit control screen of the board that is the switching source, and to enable both switching / switchback to be executed on the same screen, thereby simplifying the operator operation. Can do.

  As described above, in this embodiment, in the network connection apparatus including a plurality of operation system boards, one standby system board, and a control unit for centrally controlling them, and having an N + 1 intra-device standby switching function, the control unit is The operation of the spare board is notified to the application such as call processing as the operation of the normal operation board as the switching source, and the process is performed regardless of the N + 1 spare switching state. When an instruction such as resetting the I / F board is issued from the monitoring management apparatus, if the instruction is issued by an operator, the instruction is executed to the physical accommodation position of the board, and the configuration management function or the like automatically instructs. In this case, if N + 1 preliminary switching is being performed, a spare board is automatically selected and the process is executed. Further, the N + 1 standby switching is performed with priority given to command switching from the monitoring management apparatus over automatic switching due to a failure. If the board is command-blocked, N + 1 switching is prohibited. Further, the board for which N + 1 preliminary switching has occurred and the spare board that is not in operation are shown by changing the color of the board displayed on the node management screen on the monitoring control apparatus and displaying a switching message. For these reasons, it is possible to provide a network connection device capable of performing the redundancy switching process stably.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment.

The functional block diagram which shows embodiment of the network connection apparatus concerning this invention. FIG. 6 is a state transition diagram of N + 1 preliminary switching in the first embodiment of the present invention. The figure which shows the state transition of Lock Out command by board | substrate obstruction | occlusion. The flowchart which shows the process sequence in N + 1 preliminary | backup switching. The figure which shows an example of the node management screen in a monitoring control apparatus. The figure which shows an example of the screen which performs N + 1 preliminary switching from the monitoring control apparatus side.

Explanation of symbols

  10A1 to 10Am ... active system board, 10S ... standby system board, 20A1 to 20An ... active system board, 20S ... standby system board, 80 (80-0, 80-1) ... control switch unit, 50 ... maintenance line I / F 90, central control unit, 90a, switching processing unit, 100, switch unit, 110, memory, 110a, control data, 30, access control unit

Claims (2)

A line interface unit that converts a transmission signal introduced from a plurality of communication networks into a time-division multiplexed signal;
An exchange unit for exchanging the time-division multiplexed signal and deriving to the line interface to interconnect the plurality of communication networks;
A time division multiplex bus connecting the line interface unit and the switching unit;
The line interface unit
A plurality of operational boards respectively connected to the time division multiplex bus;
Connected to a time-division multiplex bus connected to each of the plurality of operational boards, and a standby board that forms an N + 1 redundant system with the plurality of operational boards;
In the redundant switching process between the active system board and the standby system board, the standby system board includes switching means for switching the time division multiplex bus so as to access the same time slot as the operation system board that is the switching source. Network connection device to be used. Means for selectively switching a command input destination according to a state of the redundancy switching process and a command input source when a command related to the active system board or the standby system board is input; The network connection device according to claim 1, wherein:

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