JP2014168305A - Relay apparatus and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide relay apparatus and a control method of the same that reports an occurrence of a fault to an opposite communication network even when a fault occurs in a connected communication network and a normal communication is interfered.SOLUTION: A relay apparatus (10) intervened between communication networks (20a to 20d) is provided with a monitoring part (40) that detects a fault from a certain communication network, a learning part (70) that detects a session from a reception signal received from another communication network, and a pseudo fault generation part (46) that generates a pseudo fault signal on the basis of a detection result of the monitoring part and a detection result of the learning part.

Description

  The present invention relates to a relay apparatus and a control method therefor, and more particularly to a relay apparatus that processes communication between a plurality of communication networks that provide communication services according to a predetermined communication protocol and a control method therefor.

  A relay device (gateway device (switch)) is widely used as a device that enables communication between a plurality of communication networks, particularly communication networks using different protocols.

  In a communication network, there are cases where a failure that interferes with normal communication may occur due to various factors, and the relay device has a function of monitoring the state of the communication network in order to quickly detect the failure of the communication network. There is a case.

  Also, not only one relay device for connecting a plurality of communication networks but also a plurality of relay devices are prepared, and even if a failure occurs between one relay device and a certain communication network, another relay device is used. In some cases, communication may be designed to continue. In this way, when a failure occurs in communication via a relay device that is normally used, a communication network that can switch to another relay device and realize communication to a desired communication network. This is called a communication network having a bypass function.

  For example, according to the method described in Patent Document 1, when a node detects a failure in the relay network, the node blocks the voice line of the extension network. It is also conceivable to secure a detour communication route by using a plurality of such devices.

Japanese Patent Application Laid-Open No. 11-186983

  However, according to the method of Patent Document 1, the voice line is simply blocked, and the process of actively notifying the occurrence of the failure to the communication network connected to the node is not performed. Absent. For this reason, the communication network can continue to try re-communication on the communication route in which the failure has occurred without being aware of the failure, and smooth communication such as delaying the transition to the detour route to switch to using another relay device. Various situations can be conceived that interfere with the situation.

  In view of such a problem, the present invention is directed to a communication between a communication network and another communication network that is opposite to the communication network, even if a failure occurs in the communication network and normal communication is prevented. A relay device capable of actively and surely notifying the occurrence of a failure to a communication network, and encouraging measures to shift a communication route used for communication between communication networks to a detour route, and a control method therefor are provided. The purpose is to do.

  In order to solve the above-described problems, the present invention provides a monitoring unit that detects a failure from a certain communication network, a learning unit that detects a session from a received signal received from another communication network, a detection result of the monitoring unit, and a learning unit And a pseudo fault generation unit that generates a pseudo fault signal on the basis of the detection result.

  The program according to the present invention also detects a relay device interposed between a communication network and a monitoring device for detecting a failure from a communication network and a session from a received signal received from another communication network. And a learning means that performs the function as a simulated fault generation means that generates a simulated fault signal based on the detection result of the monitoring means and the detection result of the learning means.

  The control method according to the present invention is a control method for a relay device interposed between a communication network and another communication network, the relay device detecting a failure from a communication network, and the relay device When a session for executing communication to the communication network that detected the error is detected from a received signal received from another communication network, the relay device generates a pseudo failure signal based on the failure and the session, and returns another session as a response to the session. And a step of returning to the network.

  According to the present invention, when a relay device interposed between a certain communication network detects a session from a received signal received from another communication network after detecting a failure from a certain communication network, a pseudo failure signal Therefore, the communication network opposite to the communication network where the occurrence of the failure is notified of the failure occurrence positively and surely, and the communication route for communication between communication networks is switched to the detour route. Measures can be encouraged.

It is a block diagram which shows the structure of the Example of the gateway apparatus which concerns on this invention. FIG. 2 is a block diagram schematically showing a construction example of a network using the gateway device shown in FIG. 1. It is a figure which shows an example of the pseudo failure state data memorize | stored in the memory | storage part shown in FIG. It is a block diagram which shows the internal structural example of the control part shown in FIG. 2 is a flowchart illustrating a pseudo-failure state generation operation performed by the gateway device illustrated in FIG. 1 and a communication network processing operation resulting from the operation. It is a figure which shows the generation | occurrence | production operation | movement of the pseudo-failure state which the gateway apparatus shown in FIG. 1 performs, and the processing operation of the communication network resulting from the operation | movement. 2 is a flowchart showing a recovery operation from a simulated fault state in the embodiment shown in FIG. It is a sequence chart which shows the operation | movement in the case of producing | generating a pseudo fault state using the pseudo fault state data shown in FIG. It is a block diagram which shows the structure of another Example of the gateway apparatus which concerns on this invention. It is a block diagram which shows the internal structural example of the learning part shown in FIG. It is a figure which shows an example of the pseudo fault state data memorize | stored in the memory | storage part shown in FIG. 10 is a flowchart showing an operation of analyzing a communication network failure detection method in the gateway device shown in FIG. 9.

  Next, embodiments of the gateway device according to the present invention will be described in detail with reference to the accompanying drawings. Referring to FIG. 1, an embodiment of a gateway device 10 (GW) according to the present invention performs communication between a plurality of communication networks providing a communication service according to a predetermined communication protocol (communication protocol) as necessary. A control unit 12 that performs overall control of the gateway device 10 such as communication protocol conversion is provided in conjunction with each unit to be described later of the device 10.

  Further, the gateway device 10 receives a signal including data information between the device 10 and the communication network, which is arbitrarily connected so as to be able to receive a control signal necessary for executing communication between the communication networks. It has ports 14a-14c which are interfaces for output. The detailed connection mode between the control unit 12 and the port 14 will be described later together with the connection mode of each unit in the control unit 12 and the apparatus 10.

  Further, the ports 14a to 14c are connected to the communication networks 20a to 20c via arbitrary communication lines such as communication lines 16a to 16c using a serial or parallel transmission method. Although three communication networks 20 and three ports 14 are shown in this figure, this is merely a matter of convenience for explanation. The number of communication networks 20 connected to the gateway device 10 and the number of ports 14 necessary for the communication network 20 is shown. May be arbitrary.

  With this configuration, the gateway device 10 receives information from the communication network (for example, the communication network 20a) to which the transmission source of communication information belongs, performs necessary protocol conversion by the function of the control unit 12 and the like, and the communication network to which the transmission destination belongs. By passing information to (for example, the communication network 20b), communication between different communication networks is established.

  A network constructed by connecting the communication networks 20a to 20c with the gateway device 10 is shown in FIG. Here, the communication networks 20a to 20c are communication networks having a predetermined communication protocol for each communication network, such as ISDN (Integrated Services Digital Network), Ethernet, FDDI (Fiber Distributed Data Interface), and token ring. That is, the present invention can be used even when connected to a communication network having any known communication protocol.

  The communication networks 20a to 20c are connected to each other via a plurality of gateway devices 10a and 10b. Here, the gateway device used for normal network communication is set as the device 10a.On the other hand, when a failure occurs in the route passing through the device 10a and smooth communication cannot be performed, information is replaced on the device 10a. A standby gateway device that executes transmission / reception of messages, protocol conversion, and the like is referred to as a device 10b. The communication networks 20a to 20c are also connected to the standby apparatus 10b using the communication lines 16d to 16f in the same manner as being connected to the gateway apparatus 10a using the communication lines 16a to 16c.

  In addition, the communication networks 20a to 20c have terminals 24a to 24c that are connected via lines 22a to 22c and used for operations for transmitting and receiving communication data by a user. With such a network configuration, for example, when the user of the terminal 24a intends to communicate with the user of the terminal 24b, the data input from the terminal 24a is normally transmitted through the line 22a, the communication network 20a, and the communication line 14a. The data is supplied to 10a, and necessary protocol conversion is performed by the device 10a. The converted data is transmitted to the terminal 24b via the communication line 14b, the communication network 20b, and the line 22b.

  Further, each of the communication networks 20a to 20c constituting this network has a detection unit 26a to 26c that detects a failure of the gateway device 10a that is being used for inter-network communication, and the detection unit 26a to 26c causes a failure in the gateway device 10a. When it is detected, it is assumed that switching units 28a to 28c for switching to a communication route via the gateway device 10b provided in advance are provided. That is, it is assumed that the communication networks 20a to 20c constituting the network are communication networks having a so-called detour function.

  In the description of the present embodiment, there are three communication networks 20a to 20c for convenience of explanation, but the number of communication networks 20 connected to the gateway device 10 is of course arbitrary. It is.

  With such a network configuration, for example, the device 10a is normally used for communication from the communication network 20a to the communication network 20b, and even if a failure occurs between the device 10a and the communication network 20b, the communication network 20a does not connect the device 10b. Via the communication network 22b.

  Returning to FIG. 1, the other components of the gateway device 10 will be described in more detail. In this embodiment, as shown in FIG. 1, data and signals are exchanged between the components in the apparatus 10 and the outside of the apparatus 10 via a communication bus 30 provided in the apparatus 10 and serving as a path for data and signals. Is supposed to be done through. For example, the control unit 12 is connected to the communication bus 30 via the signal line 32, and the communication bus 30 is further connected to the ports 14a to 14c via the signal lines 34a to 34c, respectively. With the configuration in which the communication bus 30 is provided in this way, transmission or reception of control signals from the control unit 12 to the ports 14a to 14c, and further signals between components in the device 10 such as the control unit 12 and each unit described later And data transmission / reception becomes possible. However, this connection mode in which the communication bus 30 is installed is merely wired as an example for the sake of convenience so that the description of the present invention is simple, and various conditions such as signal processing efficiency and manufacturing costs are considered. In addition, an optimal connection configuration may be adopted as appropriate.

  The gateway device 10 is connected to the ports 14a to 14c and the control unit 12 via the signal line 38, the communication bus 30, and the state of the communication networks 20a to 20c constantly or periodically according to the monitoring command from the control unit 12. A monitoring unit 40 for monitoring The monitoring unit 40 determines whether or not the communication network 20a to 20c has failed based on information received from the communication networks 20a to 20c via the ports 14a to 14c or by an appropriate method such as presence / absence of a response from the communication network to a signal transmitted by itself. If any of the communication networks 20a to 20c is determined to be in a failure state, a failure detection signal is transmitted to the control unit 12.

The gateway device 10 is connected to the ports 14a to 14c and the control unit 12 via the signal line 44 and the communication bus 30, and the monitoring unit 40 detects a failure between the device 10 and one of the communication networks 20. In the case where the failure occurs, a pseudo failure generation unit that generates a pseudo failure in the ports 14a to 14c connected to the communication network facing the communication network 20 in which the occurrence of the failure is detected in response to reception of the command signal from the control unit 12 Has 46.
That is, for example, when a failure is detected on the communication network 20b side as viewed from the gateway device 10, a pseudo failure is generated in the ports 14a and 14c connected to the communication networks 20a and 20c facing the communication network 20b. . In addition, when the monitoring unit 40 that has detected a failure in the communication networks 20a to 20c detects the disappearance of the failure thereafter, the pseudo failure generation unit 46 generates the ports 14a to 14c in response to a command from the control unit 12. It is also possible to eliminate pseudo-faults.

  Further, the gateway device 10 is connected to each unit such as the control unit 12, the monitoring unit 40, and the simulated fault generation unit 46 via the signal line 48 and the communication bus 30, and a protocol stack and the like for implementing communication are mounted. A storage unit 50 is included. Further, the storage unit 50 holds simulated fault state data 52 that is set as to which pseudo fault is generated in which port. In addition, the storage unit 50 can store the state of the gateway device 10 at that time, such as the presence or absence of a pseudo failure state, by receiving a storage command signal from the control unit 12.

  FIG. 3 shows an example of the simulated fault state data 52 that is set and held in the storage unit 50. As the simulated fault state data 52, various types of data D1 to D4 including data such as the route 54, the communication layer 56, the simulated fault processing 58, and the fault detection 60 of the opposite device are stored.

  In the route 54, ports 14a to 14c that are connected to the communication lines 16a to 16c and input / output signals to / from the communication networks 20a to 20c are shown.

  The communication layer 56 indicates seven communication function layers defined by the OSI reference model (Open Systems Interconnection Reference Model). For example, when the port 14a is connected to an ISDN communication network, the layer 1 (physical layer) communication function includes a bit stream transmission function or synchronization function using Bch (B channel) or Dch (D channel). In the communication layer 56 in this figure, in addition to layer 1, only layer 2 (data link layer), layer 3 (network layer), and layer 7 (application layer) are shown, but this is merely an example, This does not prevent a layer not listed in the figure from being stored as the contents of the communication layer 56.

  The pseudo fault processing 58 in the pseudo fault status data 52 is a pseudo fault status that the pseudo fault generation unit 46 specifically generates for a port connected to a communication network opposite to a communication network in which a fault has occurred. It is processing contents. For example, when the port 14a is connected to the ISDN communication network, the pseudo-failure generation unit 46 performs a process of delaying transmission of a transmission frame to the port 14a, thereby causing an out-of-sync failure to the detection unit 26a of the communication network 20a. It is identified that has occurred. The pseudo failure processing 58 stored as a part of the data 52 in the storage unit 50 includes, for example, an apparatus 10 for any communication network that can be connected to the apparatus 10 according to the present embodiment, such as an ISDN network or an Ethernet network. It is possible to set a pseudo failure to recognize that a failure has occurred.

  The failure detection 60 of the opposite device is a communication network in which any one of the pseudo failure processing 58 stored in the storage unit 50 is performed by the pseudo failure generation unit 46 of the device 10 and the pseudo abnormality state 58 is opposed to the gateway device 10. This means a specific failure state identified by the communication network 20 when 20 detection units 26 detect it.

  Therefore, based on the simulated fault status data 52 stored in the storage unit 50, the control unit 12 sets, for example, the route 54 to “port 14a”, the communication layer 56 to “layer 1”, and the simulated fault processing 58 to “send frame delay transmission”. When the execution of setting the data type D1 with the failure detection 60 of the opposite device as “out of synchronization” is commanded to the pseudo fault generation unit 46, the pseudo fault generation unit 46 executes the command to By performing a process of delay-sending the transmission frame in layer 1, the communication network 20a connected to the port 14a is made to identify the failure state of “out of synchronization”.

  Of course, the simulated fault processing 58 shown in FIG. 3 is exemplary, and the simulated fault processing 58 corresponding to the communication protocol of the communication layer 56 can be set as appropriate.

  According to FIG. 3, a plurality of simulated fault processes 58 are prepared for one port. As a result, the generated pseudo failure processing 58 can be changed every predetermined time. As a result, even if the communication network 20 connected to the gateway device 10 is, for example, a communication network having a function of automatically recovering from an out-of-synchronization state, a B & Dch frame is not transmitted to the device 10 after a predetermined time. Since another pseudo-failure process 58 is executed, it is possible to increase the probability of causing the communication network 20 to identify that the device 10 has failed.

  As described above, the control unit 12 performs overall control of the gateway device 10, but in order to help understanding of the present invention, various functions provided in the control unit 12 are used here. Several elements to be realized will be described with reference to FIG.

  In the case where a plurality of simulated fault status data 52 is stored in the storage unit 50, the control unit 12 sets the simulated fault processing 58 to be generated in the port 14 so that the simulated fault processing 58 is changed every predetermined time such as every 5 seconds. A change unit 62 that controls the generation unit 46 may be included.

  In addition, the control unit 12 is configured to execute the pseudo fault process 58 and execute the pseudo fault generated in the port 14 when it is further detected that the fault detected by the monitoring unit 40 in any of the communication networks 20 is subsequently resolved. You may have the recovery | restoration part 64 which controls the pseudo fault production | generation part 46 with which it uses for eliminating a fault.

  Furthermore, the control unit 12 determines the monitoring cycle of the monitoring unit 40 as to whether or not to detect the presence of failure every time, how many times abnormal data is detected continuously or in total, and determines that it is a failure. An adjustment unit 66 that adjusts the number of detections of the monitoring unit 40 may be provided. By providing such adjustment unit 66 and adjusting monitoring conditions according to possible abnormalities, even minor abnormalities that do not hinder communication continuity and abnormalities that can be recovered instantaneously are immediately determined as communication failures. Can be prevented.

  By the way, in the present embodiment, the control unit 12 provided in the gateway device 10, the monitoring unit 40 that monitors the communication network 20 under the control of the control unit 12, and the pseudo fault generation unit that generates the pseudo fault state 46 is shown separately to clarify the operation of the components provided in the apparatus 10. However, some or all of these components may be integrally configured in hardware or software. For example, the control unit 12 may be integrally configured to serve as the monitoring unit 40 and the simulated fault generation unit 46.

  In the present embodiment, the change unit 62, the recovery unit 64, and the adjustment unit 66 described as the internal elements of the control unit 12 are similarly provided with, for example, the change unit 62 and the recovery unit 64 as internal elements of the simulated fault generation unit 46, etc. Of course, any configuration can be adopted in the gateway device 10.

  Next, with reference to FIGS. 5 and 6, the basic operation of the device 10 and the operation of the device 10 when a communication failure occurs in any of the communication networks 20 connected to the gateway device 10 are handled. The operation of the communication network 20 will be described.

  When the gateway device 10 being processed for normal communication between the communication networks 20a and 20b is the device 10a, the monitoring unit 40 of the device 10a monitors the state of the communication networks 20a and 20b connected to the device 10a. doing. Therefore, for example, when a failure that prevents normal communication occurs between the device 10a and the communication network 20b, the gateway device 10a recognizes the occurrence of the failure through detection of the failure by the monitoring unit 40 (step S10).

  When occurrence of a failure on the communication network 20b side as seen from the gateway device 10a is detected, the control unit 12 of the device 10a sends a command to the simulated failure generation unit 46, and the simulated failure state held in the storage unit 50 Based on the data 52, the port 14a connected to the communication network 20a opposite to the communication network 20b in which the failure has occurred is shifted to a simulated failure state (step S20).

  Specifically, the pseudo fault state generated is selected from the data types D1 to D4 of the pseudo fault state data 52 according to the communication protocol of the communication network connected to each port. For example, when the communication network 20a is an ISDN network, the pseudo failure of the port 14a generated by the pseudo failure generation unit 46 according to the command of the control unit 12 is, for example, the transmission frame delay transmission of layer 1 of the data type D1. .

  Further, the gateway device 10 controls the storage unit 50 from the control unit 12 to store information indicating what kind of pseudo-failure state the device 10 itself has entered. (Step S30)

  The communication network 20a connected to the port 14a in which the pseudo failure has been generated detects that a failure has occurred in the gateway device 10 by the detection unit 26a (step S40). The communication network 20a that has detected the occurrence of a failure in the gateway device 10 is a so-called detour that passes through the standby gateway device 10b in place of the device 10a that has been used for normal network communication by the switching unit 28a. The setting is switched so that communication with the communication network 20b can be executed by the route (step S50). As a result, normal communication between the communication networks 20a and 20b is restored.

  As described above, the gateway device 10 automatically shifts the port 14a connected to the opposing communication network 20a to the pseudo-failure state when the failure of the one communication network 20b is detected, so that the other communication network 20a It is possible to actively promote bypass communication.

  In this description, the operation of the gateway device 10 for securing normal communication between the communication networks 20a and 20b when a failure occurs in the communication network 20b has been described as an example. However, of course, the operation performed by the apparatus 10 for the port 14c connected to the communication network 20c in order to ensure normal communication between the communication networks 20c and 20b is the same. Therefore, the users of the terminals 24a to 24c installed in the respective communication networks 20a to 20c can use the other terminals 24 without any change even if a failure occurs in any of the communication networks 20. It is possible to communicate with a person.

  Based on the same principle, when a detour route through the gateway device 10b is selected due to the occurrence of a failure on the communication network 20b side, the failure on the communication network 20b side is subsequently resolved, and the monitoring unit 40 of the device 10a fails. When the resolution is detected, it is possible to prompt the communication network 20a or 20c opposite to the communication network 20b to promptly restore the route between the communication networks to the normal route by the command of the recovery unit 64.

  An example of the basic operation of the device 10 that prompts the recovery from the bypass route to the normal route and the operation of the communication network 20 with respect to the operation of the device 10 will be described with reference to FIG.

  The gateway device 10a used for relaying communication between communication networks in a normal state is a monitoring unit even when the transmission and reception of communication information and the function as a protocol conversion device are suspended due to a failure on the communication network 20b side as viewed from the device 10a. 40 continues to monitor the failure state on the communication network 20b side. As a result, when the failure that has occurred between the device 10a and the communication network 20b is eventually resolved, the fact of the failure can be detected (step S60).

When the monitoring unit 40 detects the cancellation of the failure state that has occurred on the communication network 20b side, the monitoring unit 40 notifies the control unit 12 of the cancellation of the failure. Upon receiving this notification, the recovery unit 64 in the control unit 12 instructs the simulated fault generation unit 46 to finish generating the simulated fault state. Upon receiving this instruction, the simulated fault generation unit 46 returns the state of the simulated fault process 58 created for the ports 14a and 14c to the normal state (step S70). The gateway device 10 stores the state of the recovered device 10 by controlling the storage unit 50 from the control unit 12 in order to store information indicating that the device 10 has recovered from the simulated failure state. (Step S80)
The communication network 20a connected to the port 14a recovered from the pseudo failure detects that the failure state of the gateway device 10 has been recovered by the detection unit 26a (step S90), and when the failure occurs by the switching unit 28a Instead of the device 10b that has been used for the network communication, the setting is returned to execute communication with the communication network 20b using the gateway device 10a that is the route that is normally used (step S100).

  In this way, when the failure state of one communication network is resolved, the gateway device 10 is configured to promptly restore the communication route between the communication networks to the normal route so that it can be used for inter-network communication. In both the switching and the restoration of the gateway device 10 to be performed, it is possible to smoothly perform network processing without adversely affecting the user of the terminal 24.

  By the way, depending on the communication network 20, when it is detected that some kind of failure has occurred in the connected gateway device 10, it has a failure recovery function that automatically tries to overcome the failure state and continue communication. There is a case. In this case, even if a pseudo failure is created in the gateway device 10, the failure recovery function of the communication network 20 works to continue communication between networks without switching to a detour route. However, since the failure existing between the gateway device 10 and the other communication network has not been recovered, normal communication is still impossible.

  In order to prevent such a situation and to increase the probability that the communication network in use on the communication network on the other side of the failure side is identified as being in a failure state, the storage unit 50 has one port. As described above, it is possible to prepare a plurality of simulated fault processes 58 and a change unit 62 that controls the change of the simulated fault status so that the simulated fault process 58 can be changed at predetermined intervals. That's right. Here, the operation of the gateway device 10 in the case of adopting a configuration capable of generating different pseudo failure states according to time will be described.

  In the network of FIG. 2 in this description, the communication network 20a is an ISDN network, and the communication network 20c is an Ethernet. The port 14a connected to the ISDN communication network 20a is an ISDN-compatible port, and the port 14c connected to the Ethernet communication network 20c is a LAN (Local Area Network) standard IEEE 802.3 (the Institute of Electrical and Electronic Engineers 802.3). ) It shall be a compatible port. Of course, this setting condition is merely one aspect of the embodiment, and the gateway device 10 may be connected to a communication network of any communication protocol.

  When the gateway device 10 generates a pseudo failure state that changes with time, among the operations of the device 10a shown in FIGS. 5 and 6, the operations corresponding to step S20 and step S30 are repeated a plurality of times. . In this case, the operation of the gateway device 10a will be described with reference to the attached FIG.

  The gateway device 10a, which is connected to the communication networks 20a to 20c and is executing information transmission / reception and protocol conversion, monitors whether or not a communication failure has occurred in each communication network 20 by the monitoring unit 40. For example, when a failure that prevents normal communication is detected from the communication network 20b side (step S110), the monitoring unit 40 transmits a detection signal to the control unit 12 to notify the occurrence of the failure (step S120).

  The control unit 12 that has identified the occurrence of a communication failure in the communication network 20b refers to the simulated failure state data 52 held in the storage unit 50 as a process for automatically shifting the gateway device 10a to the simulated failure state (step S130). ), For example, a command is sent to the pseudo-failure generator 46 so as to realize the setting of the data type D1 described at the top (step S140). The simulated fault generation unit 46 that has received the command performs a process of generating a simulated state of the data type D1 (step S150). Specifically, the simulated fault generation unit 46 transmits frames at an interval exceeding the transmission timing defined in the protocol stack installed in the storage unit or the like in layer 1 of the port 14a. For example, when the protocol stack has an interval of 1 second, it is transmitted at an interval exceeding 1 second such as 1.3 seconds. Further, when the communication timing is synchronized between the gateway device 10a and the communication network 20a, the frame is intentionally transmitted at a timing deviating from the synchronization. In this way, the communication network 20a, which is the opposite device, is made to identify the failure state of “out of synchronization”.

  After the simulated fault state set to the data type D1 is executed in the gateway device 10a, the control unit 12 stores in the storage unit 50 information indicating that the device 10 itself has entered the simulated fault state of the data type D1. Control is performed (step S160).

  Thereafter, after a predetermined time such as 5 seconds elapses, the control unit 12 including the changing unit 62 starts control for changing the simulated fault processing 58 generated in the port 14a. First, the control unit 12 refers to the simulated fault state data 52 held in the storage unit 50 (step S170), and this time, the simulated fault generation unit 46 implements the setting of the data type D2 as the next data related to the port 14a. (Step S180). Upon receiving the command, the simulated fault generation unit 46 performs processing for generating a simulated state of the data type D2 (step S190). Specifically, the simulated fault generator 46 performs a process of not sending out the B & Dch frame in the layer 2 of the port 14a. Here, when the B & Dch frame is not transmitted, the control unit 12 controls each unit so as not to transmit the call control message and the packet information based on the call control message defined by the protocol stack implemented in the gateway device 10. To do. In this way, the communication network 20a which is the opposite device is caused to identify the failure state of “communication failure”.

  After the simulated fault state set to the data type D2 is executed in the gateway device 10a, the control unit 12 stores in the storage unit 50 information indicating that the device 10 itself has entered the simulated fault state of the data type D2. Control is performed (step S200).

  Thereafter, after a predetermined time such as 5 seconds elapses, the control unit 12 refers to the simulated fault state data 52 held in the storage unit 50 again (step S210). Since all the next data related to the port 14a has already been executed, the control unit 12 including the changing unit 62 subsequently sends a command to the simulated fault generation unit 46 to realize the setting of the data type D3 that is the data related to the port 14c. (Step S220). The simulated fault generation unit 46 that has received the command performs a process of generating a pseudo state of the data type D3 (step S230). Specifically, the simulated fault generation unit 46 performs processing for non-sending ICMP Replay (Internet Control Message Protocol Replay) in the layer 3 of the port 14c. Here, when ICMP Replay is not transmitted, the control unit 12 performs processing for not transmitting ICMP Replay based on the ICMP message defined by the protocol stack implemented in the gateway device 10. Therefore, even if the gateway device 10 receives a ping (Echo Request) from the communication network 20c, no ping response is returned from the device 10 side. In this way, the communication network 20c, which is the opposite device, is made to identify the failure state of “heartbeat loss”.

  After the simulated fault processing 58 set to the data type D3 is executed in the gateway device 10a, the control unit 12 stores information indicating that the device 10 itself is in the simulated fault state of the data type D3 in the storage unit 50. Control to store is performed (step S240).

  Thereafter, after a predetermined time such as 5 seconds elapses, the control unit 12 including the changing unit 62 refers to the simulated fault state data 52 held in the storage unit 50 again (step S250). As the data, a command is sent to the simulated fault generation unit 46 so as to realize the setting of the data type D4 (step S260). The simulated fault generation unit 46 that has received the command performs a process of generating a simulated state of the data type D4 (step S270). Specifically, the simulated fault generation unit 46 performs a process of not sending an SNMP Trap (Simple Network Management Program Trap) in the layer 7 of the port 14c. Here, when SNMP Trap is not transmitted, the control unit 12 performs processing for not transmitting SNMP Trap based on the SNMP message defined by the protocol stack implemented in the gateway device 10. Therefore, the transmission of the SNMP Trap that the gateway device 10 transmits to the communication network 20c according to the standard is stopped. In this way, the communication network 20c, which is the opposite device, is made to identify the “failed monitoring” failure state.

  After the simulated fault processing 58 set to the data type D4 is executed in the gateway device 10a, the control unit 12 stores information indicating that the device 10 itself is in the simulated fault state of the data type D4 in the storage unit 50. Control to store is performed (step S280).

  As described above, the gateway device 10 changes the content of the pseudo-failure generated in the device every predetermined time, so that the communication network 20 connected to the device 10 is a communication network having a failure automatic recovery function. Even if there is, it is possible to increase the probability that the communication network 20 identifies the occurrence of the failure based on the simulated failure state of the device 10. As a result, it is possible to promptly switch to the detour communication route.

  The selection order of the actually generated simulated fault state data 52 is arbitrary. Further, not only a pseudo failure state may be sequentially created for each port, but also a process of simultaneously creating a pseudo failure state for a plurality of ports may be performed.

  In the description so far according to the embodiment of the present invention, it has been described that the communication network in which the failure first occurs is the communication network 20b connected to the port 14b, but which communication network is the communication network in which the failure has occurred. Even in this case, the gateway device 10 can identify the occurrence of the pseudo failure in the opposite communication network group by performing the above-described operation on the other ports.

  Next, another embodiment of the gateway device 10 according to the present invention will be described. In the gateway device 10 according to this embodiment, for example, when a new communication network 20d is connected to the gateway device 10 in operation, what method the communication network 20d uses to detect the occurrence of a failure in the device 10 Can be analyzed.

  The configuration of the gateway device 10 according to the embodiment described here is as shown in FIG. The same parts as those in the previous embodiment are denoted by the same reference numerals. It is assumed that the gateway device 10 according to the present invention has ports 14a to 14d, and a new communication network 20d is connected to the port 14d.

  Similar to the communication networks 20a to 20d shown in FIG. 2, the communication network 20d includes a detection unit 26d that detects a failure of the gateway device 10 and a switching unit 28d that switches a communication route. However, in the new connection stage, the gateway device 10 does not recognize what kind of failure detection means or method the detection unit 26d is.

  The gateway device 10 according to the present embodiment includes a learning unit 70 that is connected to the communication bus 30 via a signal line 68. The learning unit 70 detects periodic communication out of communication per predetermined unit time from each communication network 20 under the control of the control unit 12, translates the communication protocol using the protocol stack, and translates the information Is a device that performs processing for storing the information in the storage unit 50. Further, the learning unit 70 performs periodic communication detection, collation, and storage processing every unit time, and compares the storage history of each time to the newly connected gateway device 10 to the communication network 20d. This is a device that estimates and analyzes the failure detection method adopted by the company.

  The unit time at the time of detection may be an arbitrary time such as 10 minutes after the gateway device 10 is activated. Here, when the starting point of the unit time is the starting time of the device 10, the control unit 12 performs control so that, for example, the gateway device 10 is restarted once every time detection of periodic communication is started.

  An example of the configuration of the learning unit 70 will be described more specifically with reference to FIG. First, the learning unit 70 may include a periodic signal detection unit 72 that monitors a signal newly transmitted from the communication network 20d connected to the port 14d and detects a signal received periodically. In addition, the learning unit 70 can include a translation unit 74 that translates a communication protocol based on a protocol stack stored in the storage unit 50 for the periodic signal detected by the periodic signal detection unit 72. Further, the learning unit 70 compares the translation results for a predetermined number of times stored in the storage unit 50 and estimates and analyzes a failure detection method performed by the communication network 20d by means such as deriving a common point, for example. You may have.

  For example, in each storage history, if the storage unit 50 stores a detection and translation result that a ping is periodically transmitted from the newly connected communication network 20d to the gateway device 10, the ping is a layer Since the communication confirmation using the ICMP defined by the protocol located at 3 is performed, the analysis unit 76 analyzes that the specific abnormality detection method adopted by the communication network 20d is the communication confirmation by ping.

  The storage unit 50 stores a detection and translation result indicating that a session with a predetermined port such as TCP 80 (Transmission Control Protocol 80) is established again from the communication network 20d every time the apparatus 10 is restarted. In this case, the learning unit 70 determines the maintenance of the continuous session during the detection period as a kind of periodic communication, and the detection method used by the communication network 20d detects an abnormality of the device 10 by disconnecting the TCP session. Analyze that it is.

  In the storage unit 50, simulated fault state data 152 as shown in FIG. 11 as an example is set and held. As the simulated fault state data 152, various types of data D5 to D10 including data such as the communication layer 56, the simulated fault process 58, and the fault detection 60 of the opposite device are stored. In the simulated fault status data 152 of this embodiment, as the simulated fault processing 58, RIP (Routing Information Protocol) is added to the data D6 in addition to the ICMP non-transmission (data D5) stored as the simulated fault status of the previous embodiment. ) Response not transmitted, TCP FIN (Transmission Control Protocol Finish) for data D7, IGMP (Internet Group Management Protocol) query & report not transmitted for data D8, HTTP (HyperText Transfer Protocol) status code 500 returned for data D9, and HTTP for data D10 Status code 201 non-transmission is also stored.

  In the case of the present embodiment, the storage unit 50 stores the analysis result according to an instruction from the control unit 12. As a result, when it becomes necessary to generate a simulated fault state for the communication network 20d in the future, it is possible to generate a simulated fault of an appropriate layer using the stored analysis result and the simulated fault status data 152. It becomes.

  Next, an analysis operation when a new communication network 20d is connected to the gateway device 10 according to the present embodiment will be described with reference to FIG. When the communication network 20d is newly connected to the port 14d of the gateway device 10, the periodic signal detection unit 72 performs a period of communication performed between the communication network 20d and the device 10 for a predetermined unit time. A typical communication is detected (step S310). After the unit time has elapsed, the translation unit 74 translates the communication protocol using the protocol stack for the detected periodic communication (step S320). The result of the communication information translated by the learning unit 70 is stored in the storage unit 50 as a history for analysis under the control of the control unit 12 (step S330).

  Here, the learning unit 70 determines whether or not a predetermined number of histories are stored (step S340). If the number of stored histories is less than the predetermined number, the process returns to step S310 to continue detecting, translating, and storing communications. On the other hand, when a predetermined number of histories are stored, the analysis unit 76 analyzes the failure detection method of the newly connected communication network 20d based on the history stored so far (step S350). After analyzing the communication network failure detection method, the storage unit 50 stores the analysis result (step S360).

  As described above, by using the gateway device 10 according to the present embodiment, it is possible to automatically analyze the failure detection method of the newly connected communication network 20d. Therefore, even if a communication failure occurs later in another communication network without requiring any special management work by the administrator, the gateway device 10 can save the communication network 20d based on the stored analysis result. It is possible to generate a pseudo-failure state of an appropriate layer and prompt the communication network 20d to switch the communication route detour.

  In addition, if a plurality of simulated fault state data 152 is prepared for each layer as shown in FIG. 11, the change unit 62 based on the data 152 controls the predetermined time by the method shown in FIG. It is possible to change the contents of the pseudo-fault generated every time. As a result, even if the communication network 20d is a communication network having a failure automatic recovery function, it is possible to increase the probability that the communication network 20d identifies the occurrence of the failure based on the pseudo failure state of the gateway device 10. . Of course, the order of change of the pseudo states to be generated can be set arbitrarily.

  The embodiments of the present invention have been described so far. However, the embodiment is not limited to the above-described embodiments, and the design and operation procedures are appropriately performed as long as the present invention can be implemented. You can make changes.

10 Gateway device
14 ports
40 Monitoring unit
46 Simulated fault generator
50 storage
52 Simulated fault condition data
64 Change
64 Recovery Department
70 Learning Department
72 Periodic signal detector
74 Translation Department
76 Analysis unit
152 Simulated fault condition data

Claims (15)

A relay device interposed between the first communication network and the second communication network, the device comprising:
A monitoring unit for detecting a failure from the second communication network;
A learning unit for detecting a session from a received signal received from the first communication network;
A relay apparatus comprising: a pseudo fault generation unit that generates a pseudo fault signal based on a detection result of the monitoring unit and a detection result of the learning unit.   The relay apparatus according to claim 1, wherein after the monitoring unit detects a failure, the pseudo failure generation unit generates the pseudo failure signal when the learning unit detects a session. The apparatus of claim 2.
The received signal is a signal from the first communication network to the second communication network;
The learning device translates a communication protocol for the received signal and detects a session of a predetermined port in the predetermined communication protocol.   4. The relay apparatus according to claim 3, wherein the predetermined communication protocol is TCP (Transmission Control Protocol), and the predetermined port is a port 80.   5. The relay apparatus according to claim 4, wherein the simulated fault signal generated by the simulated fault generation unit includes an HTTP (HyperText Transfer Protocol) status code.   6. The relay apparatus according to claim 5, wherein the HTTP status code is a content indicating an error.   The relay apparatus according to claim 6, wherein the HTTP status code is a status code 500. 8. The device according to any one of claims 1 to 7, further comprising:
A first port which is an interface connected to the first communication network and transmits / receives signals to / from the first communication network; and a second port which is connected to the second communication network and transmits / receives signals to / from the second communication network. Have
The monitoring unit detects a failure from the second communication network via the second port;
The learning unit detects a session from the received signal received from the first communication network via the first port;
The relay device according to claim 1, wherein the first port transmits the pseudo failure signal to the first communication network. The apparatus according to claim 8.
The monitoring unit detects presence or absence of a failure based on information received from the second communication network or according to presence or absence of a response from the second communication network to a signal transmitted by itself,
The relay device according to claim 1, wherein the first port transmits the pseudo failure signal to the first communication network as a return to the session.   2. The apparatus according to claim 1, wherein when the first communication network and the second communication network are communication networks that provide communication services according to different communication protocols, the relay device relays communication by performing protocol conversion. A relay device characterized by that.   11. The apparatus according to claim 10, wherein the first communication network and the second communication network are networks corresponding to any of ISDN (Integrated Services Digital Network), Ethernet, and FDDI (Fiber Distributed Data Interface), respectively. A relay device. A relay device interposed between the first communication network and the second communication network;
Monitoring means for detecting a failure from the second communication network;
Learning means for detecting a session from a received signal received from the first communication network, and functioning as a pseudo fault generation means for generating a pseudo fault signal based on the detection result of the monitoring means and the detection result of the learning means Program. A control method for a relay device interposed between a first communication network and a second communication network,
The relay device includes a monitoring unit, a learning unit, and a simulated fault generation unit, and the method includes:
A first step of detecting a failure from the second communication network in the monitoring unit;
A second step of detecting a session from a received signal received from the first communication network in the learning unit;
The simulated fault generation unit includes a third step of sending a simulated fault signal to the first communication network based on the detection result detected in the first step and the detection result detected in the second step. A control method characterized by the above. A method for controlling a relay device interposed between a first communication network and a second communication network, the method comprising:
The relay device detecting a failure from the second communication network;
When the relay device detects a session for executing communication to the second communication network in which the failure is detected from a received signal received from the first communication network, the relay device generates a pseudo failure signal based on the failure and the session. And generating and returning the simulated fault signal to the first communication network as a response to the session. A relay device interposed between the first communication network and the second communication network, the device comprising:
A monitoring unit for detecting a failure from the second communication network;
A learning unit that translates a communication protocol for a relay signal from the first communication network to the second communication network and detects a session of port 80 in the communication protocol TCP (Transmission Control Protocol);
A pseudo fault generation unit that generates HTTP (HyperText Transfer Protocol) pseudo fault in the relay device based on the detection result of the monitoring unit and the detection result of the learning unit;
A storage unit for storing second HTTP simulated fault status data different from the first HTTP simulated fault status data and the first HTTP simulated fault status data for setting the HTTP simulated fault generated by the simulated fault generation unit;
The simulated fault generation unit generates the HTTP simulated fault based on the first HTTP simulated fault status data or the second HTTP simulated fault status data as a response to the session,
When generating the HTTP simulated fault based on the first HTTP simulated fault status data, the relay apparatus returns an HTTP simulated fault signal including a predetermined HTTP status code as a response to the session to the first communication network, and the second HTTP simulated fault is transmitted. A relay device, wherein when generating the HTTP pseudo failure based on failure state data, the relay device performs processing different from the return.

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