JP6046664B2 - COMMUNICATION SYSTEM, DETECTION DEVICE, AND DETECTION METHOD - Google Patents

Description

  The present invention relates to a communication system, a detection device, and a detection method for detecting a communication loop in a network connecting a gateway device and a plurality of switch devices.

  Base station apparatuses used for mobile communication are connected by a network. In such a network, a communication loop may occur in the data link layer due to a failure of an in-network device or an in-network operation. When a communication loop occurs, packets multiply in the network, and the load on all base station devices connected to the network increases.

  When such a loop occurs, the network administrator refers to the work management list and the work log of the devices in the network, and determines whether the line suspected of being a loop is the source of the loop one line at a time. Is evaluated.

  In recent years, with the increase in the number of base station apparatuses, EoE (Ethernet over Ethernet, Ethernet is a registered trademark) technology is applied to a network connecting base station apparatuses. Specifically, EoE technology is applied to a network that connects a switch device connected to a base station device and a gateway device connected to a switching facility. Thereby, control of the communication apparatus (core switch) in the network can be simplified.

  Patent Document 1 discloses a system for specifying a loop position in a network to which EoE technology is applied.

Japanese Patent No. 5019520

The test apparatus described in Patent Document 1 transmits a test frame having a destination address that is flooded and transferred to a network to which the EoE technology is applied, and detects the occurrence of a loop when the test frame is returned. However, when a phenomenon such as a broadcast storm has already occurred in the network, a frame having a broadcast address or a multicast address may be discarded by a communication device in the network. In addition, when performing flooding transfer using a unicast address, it is necessary to obtain in advance an address that is not recorded in the MAC address table.
An object of the present invention is to provide a communication system, a detection apparatus, and a detection method for detecting a communication loop in a network without transmitting a test frame.

(1) According to one aspect of the present invention, a plurality of switch devices connected to a communication device, a gateway device connected to each of the switch devices through the same network, and detection for detecting a communication loop in the communication device The gateway device stores a transmission source address based on a frame transmitted from a plurality of communication devices and switch devices, and the detection device includes a first transmission source address of an interface of the switch device An acquisition unit that acquires a correspondence table between the interface of the communication device connected to the interface and a second transmission source address from the gateway device, and the first transmission source address based on the correspondence table If the correspondence between the second source address many-to-one or many-to-many in such shall there are a plurality, the corresponding First when the transmission can identify the switch device having a source address interface, the communication system comprising a detection unit for generating a loop information indicating whether loop communication to the communication device occurs in common with engaging It is.

  (2) In one aspect of the present invention, in the above (1), the correspondence table may be a correspondence table used by the gateway device for address resolution.

(3) According to one aspect of the present invention, in the above (1) or (2), the acquisition unit acquires the correspondence table from the gateway device a plurality of times at different timings, and the detection unit includes a plurality of the correspondences Even if the table is merged for each second source address, and the loop information is generated based on the correspondence between the first source address and the second source address after merging. good.

(4) One aspect of the present invention, Oite above (3), the detection unit merges the correspondence table for each of the second source address to the first source address of the merged When the corresponding second source address is the same as the source address of the communication device connected to the local port of the gateway device, the switch device having the interface of the first source address is specified. The communication device connected to the switch device may be a communication device in which a communication loop has occurred.

(5) One aspect of the present invention, Oite above (3) or (4), wherein the detection unit merges the correspondence table for each of the second source address, the merged first When there are a plurality of one-to-one or many-to-many correspondence relationships between a transmission source address and the second transmission source address, a switching device having an interface of a first transmission source address common to the correspondence relationship The communication device connected to the switch device may be a communication device in which a communication loop has occurred.

( 6 ) According to one aspect of the present invention, in the above ( 4 ) or ( 5 ), the detection unit includes a communication device that is connected to the specified switch device in a one-to-one relationship. It may be configured as follows.

( 7 ) In one aspect of the present invention, in any one of (1) to ( 6 ), the second transmission source address is a transmission source frame transmitted from the communication device. The configuration may be an address used when encapsulated with.

( 8 ) In one aspect of the present invention, in any one of the above (1) to ( 7 ), the second transmission source address is a transmission source address of a base station device, and the detection unit It may be configured to detect a base station apparatus in which a loop has occurred.

( 9 ) In one aspect of the present invention, in any one of the above (1) to ( 8 ), the second transmission source address is a transmission source address of a base station device, and the network includes the base station A gateway device corresponding to a communication type of the device, and the detection device includes a selection unit that selects a gateway device that acquires the correspondence table based on the input communication type of the base station device, and the detection unit The configuration may be such that the correspondence table is acquired from the gateway device selected by the selection unit.

( 10 ) In one aspect of the present invention, in any one of (1) to ( 9 ), the second transmission source address is a transmission source address of a base station device, and the network is provided for each service area. And the detection device includes a selection unit that selects a gateway device that obtains the correspondence table based on information indicating the input service area, and the detection device is connected to the plurality of base station devices. The unit may be configured to acquire the correspondence table from the gateway device selected by the selection unit.

(11) One embodiment of the present invention detects a communication loop in the communication device in a network connecting a plurality of switch devices connected to the communication device and a gateway device connected to each of the switch devices. It is a detection device, and obtains a correspondence table between a first transmission source address of the interface of the switch device and a second transmission source address of the interface of the communication device connected to the interface from the gateway device. an acquisition unit, based on said correspondence table, when the first source address and said second correspondence between the transmission source address is many-to-one or many-to-many in such shall there are a plurality, the corresponding If you can identify a switch device having a first interface of the source address of the common relationship of communication to the communication device Le A detection apparatus and a detection unit for generating a loop information indicating whether flop has occurred.

(12) One aspect of the present invention is a method for detecting a communication loop in a communication device in a network connecting a plurality of switch devices connected to the communication device and a gateway device connected to each of the switch devices. An acquisition step of acquiring a correspondence table between a first transmission source address of the interface of the switch device and a second transmission source address of the interface of the communication device connected to the interface from the gateway device. If, on the basis of the correspondence table, when the first source address and a to the second corresponding relationship is many-to-one or many-to-many transmission source address shall there are a plurality, in the relationship If you can identify a switch device having a first interface of the source address of the common, the communication to the communication device Lou There is a detection method comprising a detection step of generating a loop information indicating whether occurred.

  According to at least one of the above aspects, the detection device generates loop information indicating whether or not a loop has occurred based on a correspondence table included in the gateway device connected to each switch device. Since the gateway device is connected to each switch device, the correspondence table shows the relationship between all the switch devices provided on the network and communication devices connected to each switch device. Thus, the detection apparatus can detect a communication loop in the network without transmitting a test frame.

It is the schematic which shows the structure of the communication system which concerns on 1st Embodiment. It is a schematic block diagram which shows the structure of a detection apparatus. It is a figure which shows an example of the behavior of the MAC address table of a gateway apparatus when a communication loop arises. It is an example of the screen displayed on a display when a user accesses a detection apparatus. It is a flowchart which shows the detection process of the loop by the detection apparatus which concerns on 1st Embodiment. It is an example of the screen displayed on a display as a result of the detection process of a loop. It is a figure which shows an example of the behavior of the MAC address table of the gateway apparatus which concerns on 2nd Embodiment when a communication loop arises. It is a flowchart which shows the detection process of the loop by the detection apparatus which concerns on 2nd Embodiment.

<< First Embodiment >>
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic diagram illustrating a configuration of a communication system 1 according to the first embodiment.
The communication system 1 according to the first embodiment performs communication related to mobile communication. The communication system 1 includes an exchange facility 10, a gateway device 20, a plurality of base station devices 30, a plurality of switch devices 40, a database device 50, and a detection device 60. The switch device 40 and the gateway device 20 are connected to each other via the same relay network N (network). The relay network N is a wide area Ethernet (registered trademark) network, and is provided for each communication method and each service area. Examples of communication methods include LTE (Long Term Evolution), CDMA (Code Division Multiple Access) 2000 1x, CDMA2000 1xEV-DO Revision A, and the like.
In the present embodiment, the exchange facility 10 and the base station device 30 are examples of communication devices.

The switching facility 10 is a facility that performs circuit switching between terminals M that perform mobile communication and connection between the terminal M and an external network. The exchange facility 10 is connected to the network via the gateway device 20. The exchange facility 10 is provided for each communication method and each service area.
The gateway device 20 is a device that mediates communication between the switch device 40 and the exchange facility 10 by mutually converting a protocol used for communication with the switch device 40 and a protocol used for communication with the exchange facility 10. The gateway device 20 is provided on a one-to-one basis with respect to the exchange facility 10. That is, the gateway device 20 is provided for each communication method and each service area.
The base station device 30 is a device that wirelessly connects to a terminal M that performs mobile communication and relays communication between the terminals M. The base station device 30 is connected to the network via the switch device 40.
The switch device 40 is a device that mediates communication between the base station device 30 and the gateway device 20.
That is, when communication is performed using the terminal M, communication is always performed between the switch device 40 and the gateway device 20. In the present embodiment, the switch devices 40 do not communicate with each other without going through the gateway device 20.

  The gateway device 20 and the switch device 40 have an EoE function. That is, when the gateway device 20 and the switch device 40 communicate via the relay network N, the target frame is stored in a frame whose destination is the MAC address (EoEMAC address) of the external interface of the counterpart device (capsule) To transmit. In the present embodiment, the external interface refers to an interface connected to a communication device (such as the exchange facility 10 or the base station device 30) that performs communication via the relay network N. Therefore, the MAC address tables of the gateway device 20 and the switch device 40 are stored in association with the MAC address of the base station device 30 or the switching facility 10, the EoEMAC address of the gateway device 20 or the switch device 40, and the port number of the own device. To do. The MAC address table is a correspondence table used by the gateway device 20 and the switch device 40 for address resolution, and is updated every time frame communication is performed. In the present embodiment, the EoEMAC address of the gateway device 20 or the switch device 40 is an example of a first transmission source address. In the present embodiment, the MAC address of the base station device 30 or the exchange facility 10 is an example of a second transmission source address of the switch device 40. Note that the MAC address of the base station device 30 or the exchange facility 10 is specifically the MAC address of the interface of the base station device 30 or the exchange facility 10 connected to the external interface of the gateway device 20 or the switch device 40. is there. The EoE function is also called “MAC IN MAC”.

The database device 50 stores a base station table that stores information about the base station device 30, a switch table that stores information about the switch device 40, and a gateway table that stores information about the gateway device 20.
The base station table includes the name of the base station device 30, the access line ID of the base station device 30, the address of the base station device 30, the switch device 40 connected to the base station device 30 and its port number. Associate and store.
The switch table stores the EoEMAC address, the name of the switch device 40 indicated by the EoEMAC address and the port number thereof, and the name of the gateway device 20 of the relay network N to which the switch device 40 is connected.
The gateway table stores the name of the gateway device 20, the communication method of the gateway device 20, and the MAC address of the local port of the gateway device 20 in association with each other.

The detection device 60 detects a communication loop in the base station device 30. The detection device 60 is connected to the gateway switch.
FIG. 2 is a schematic block diagram showing the configuration of the detection device 60.
The detection device 60 includes an input unit 61, a selection unit 62, an acquisition unit 63, a table storage unit 64, a detection unit 65, and an output unit 66.

The input unit 61 receives an input of a loop detection start instruction in the base station device 30 connected to the communication system 1 from the administrator of the communication system 1.
The selection unit 62 selects the gateway device 20 that acquires the MAC address table based on the information indicating the communication type and service area of the base station device 30 input to the input unit 61.
The acquisition unit 63 acquires the MAC address table from the gateway device 20 a plurality of times at different timings when the input unit 61 receives an input of a loop detection start instruction.
The table storage unit 64 stores a plurality of MAC address tables acquired by the acquisition unit 63.
Based on the plurality of MAC address tables stored in the table storage unit 64, the detection unit 65 generates loop information indicating whether or not a communication loop has occurred in the base station device 30.
The output unit 66 outputs the loop information generated by the detection unit 65 to a display or the like.

Here, a loop detection method in the present embodiment will be described.
When a communication loop occurs in the base station device 30, the frame transmitted from the exchange facility 10 is transmitted to the switch device 40 as an unknown unicast frame in the base station device 30. An unknown unicast frame is a frame transmitted to all ports other than the transmission source when the transmission destination target port is not learned in the MAC address table. Therefore, if there is a communication loop in the base station device 30, the unknown unicast frame is looped back to the same base station device 30, and then the unknown unicast frame is looped back to the transmission source switch device 40.

  When the unknown unicast frame is transmitted to the switch device 40, the switch device 40 converts the unknown unicast frame into an EoE packet and transmits it to the relay network N by multicast. Thereby, the gateway apparatus 20 receives an unknown unicast frame from the switch apparatus 40, and updates a MAC address table.

FIG. 3 is a diagram illustrating an example of the behavior of the MAC address table of the gateway device 20 when a communication loop occurs.
As described above, the unknown unicast frame is generated by folding a frame transmitted from the exchange facility 10. Therefore, the MAC address of the transmission source of the unknown unicast frame indicates the MAC address of the exchange facility 10. Therefore, the gateway device 20 switches the EoEMAC address associated with the MAC address of the exchange facility 10 in the MAC address table as shown in FIG. 3A from the local port of the own device as shown in FIG. The EoEMAC address of the device 40 is rewritten. Thereafter, when the gateway device 20 receives a frame from the switching facility 10, the gateway device 20 automatically sets the EoEMAC address associated with the MAC address of the switching facility 10 in the MAC address table, as shown in FIG. Rewrite to the local port of the device. By repeating this process, the EoEMAC address associated with the MAC address of the exchange facility 10 in the MAC address table of the gateway device 20 is frequently rewritten.

  Therefore, the detection unit 65 identifies the switch device 40 having the interface of the rewritten EoEMAC address, and sets the base station device 30 connected to the switch device 40 as the base station device 30 in which the communication loop has occurred.

Next, a loop detection procedure in the communication system 1 according to the present embodiment will be described in detail.
In the present embodiment, the administrator of the communication system 1 is notified of the ID of the access line in which the communication failure has occurred from the monitor who monitors the failure of the mobile communication, and the cause of the failure is due to the loop. The detection procedure when detecting whether or not will be described.

FIG. 4 is an example of a screen displayed on the display when the user accesses the detection device 60.
When the administrator of the communication system 1 accesses the detection device 60 using a PC (Personal Computer), the output unit 66 of the detection device 60 displays the screen shown in FIG. 4A on the PC. On the PC screen, as shown in FIG. 4A, an input text form that accepts an input of an access line ID, and a search that starts a search for the base station apparatus 30 that has the access line ID entered in the input text form Button.

  When the administrator operates the PC to input the ID of the access line where the communication failure has occurred and presses the search button, the input unit 61 receives the input. Next, the selection unit 62 reads the name of the base station device 30 associated with the access line ID from the base station table of the database device 50. Since base station apparatus 30 belongs to one service area, specifying base station apparatus 30 is equivalent to specifying the service area. And the output part 66 displays the base station apparatus 30 read from the database apparatus 50 on the screen of PC as a search result as shown in FIG.4 (B). At this time, the access line ID is provided with a link for displaying detailed information.

  When the administrator selects the link by operating the PC, the input unit 61 receives the input. The selection unit 62 reads the name and address of the base station device 30 associated with the access line ID and the name and port number of the switch device 40 to which the base station device 30 is connected from the base station table of the database. Next, the selection unit 62 reads the name of the gateway device 20 associated with the read name of the switch device 40 and the communication method of the gateway device 20 from the gateway table of the database. That is, the selection unit 62 extracts the gateway device 20 based on the name of the base station device 30 input to the input unit 61. And the output part 66 shows the information of the base station apparatus 30 read from the database apparatus 50, and the information of the gateway apparatus 20 for every communication type connected to the said base station apparatus 30 as shown in FIG.4 (C). Is displayed on the PC screen. At this time, a link for analyzing the FDB (Forwardin DataBase) of the gateway apparatus 20 having the communication type is provided in the information of each gateway apparatus 20.

  When the administrator selects the link by operating the PC, the input unit 61 receives the input. The selection unit 62 selects the gateway device 20 as the gateway device 20 that acquires the MAC address table, based on the communication type indicated by the link received by the input unit 61. Next, the acquiring unit 63 accesses the selected gateway device 20 and acquires an FDB entry. Then, the output unit 66 displays the FDB entry acquired from the gateway device 20 and a start button for starting loop detection in the relay network N connected to the gateway device 20 as shown in FIG. On the screen. When the administrator presses the start button by operating the PC, the input unit 61 receives the input. Thereby, the detection apparatus 60 starts a loop detection process.

FIG. 5 is a flowchart illustrating a loop detection process performed by the detection device 60 according to the first embodiment.
The acquiring unit 63 accesses the selected gateway device 20 and acquires the MAC address table a plurality of times (for example, three times) at different timings (step S1). Specifically, the acquisition unit 63 inputs a MAC address table output command to the gateway device 20 and acquires the MAC address table output from the gateway device 20 according to the output command. There is a time difference between when the acquisition unit 63 inputs an output command and when the gateway device 20 finishes outputting all the MAC address tables. Therefore, the acquisition unit 63 can acquire the MAC address table at different timings by inputting the next output command as soon as the MAC address table is acquired. Further, when acquiring the MAC address table, the acquiring unit 63 records the MAC address table in the table storage unit 64.

  The acquisition unit 63 can acquire the MAC address table at a high speed by inputting an output command of an MIB (Management information base) object of the MAC address table to the gateway device 20. This is because the time required to output the MAC address table collectively by the MIB object is shorter than the time required to output the MAC address table one entry at a time.

  When the acquisition unit 63 acquires a plurality of MAC address tables, the detection unit 65 creates an address / accommodation correspondence table by merging the plurality of MAC address tables for each MAC address (step S2). Specifically, the detection unit 65 collects each entry of a plurality of MAC address tables into one table, and deletes an entry having a duplicate combination of the EoEMAC address and the MAC address of the communication device from the table. Create a correspondence table.

  Next, the detection unit 65 determines whether or not there is a combination in which the EoEMAC address and the MAC address of the communication device have a many-to-one relationship in the created correspondence table (step S3). That is, the detection unit 65 determines whether or not the MAC address of one communication device is associated with a plurality of EoEMAC addresses. The MAC address of the communication device indicates the MAC address of the exchange facility 10. When the detection unit 65 determines that there is no many-to-one relationship between the EoEMAC address and the MAC address of the communication device (step S3: NO), a communication loop has occurred in the base station device 30. Loop information indicating that there is no data is generated (step S4). That is, the detection unit 65 determines that a communication loop has not occurred in the base station device 30 when the EoEMAC address and the MAC address of the communication device are all in a one-to-one or one-to-many relationship. . This is because a plurality of base station devices 30 may be connected to one switch device 40.

  On the other hand, when the detection unit 65 determines that there is a many-to-one relationship between the EoEMAC address and the MAC address of the communication device (step S3: YES), the detection unit 65 connects to the communication device in which the communication loop has occurred. The switched switch device 40 is specified (step S5). Specifically, the detection unit 65 uses the switch device 40 having the interface indicated by the one that is not the local port of the gateway device 20 among the EoEMAC addresses as the switch device 40 connected to the communication device in which the communication loop has occurred. Identify. This is because the switch devices 40 installed at different bases are not connected to the same base station device 30.

  Next, the detection unit 65 identifies the base station device 30 corresponding to the EoEMAC address indicating the interface of the switch device 40 identified in the correspondence table as the base station device 30 in which a communication loop has occurred, and Loop information indicating the base station device 30 in which the loop has occurred is generated (step S6).

Then, the output unit 66 displays the loop information generated in step S4 or step S6 on the PC screen as a detection result (step S7).
FIG. 6 is an example of a screen displayed on the display as a result of the loop detection process.
FIG. 6A is a screen example when the detection unit 65 displays the loop information generated in step S4. As shown in FIG. 6A, the output unit 66 informs the PC that it did not detect rewriting of the MAC address table and that it could not detect rewriting of the MAC address table due to timing. Display. Further, the output unit 66 displays a detection process re-execution button on the PC. When the administrator presses the start button by operating the PC, the detection device 60 re-executes the loop detection process.
FIG. 6B is an example of a screen when the detection unit 65 displays the loop information generated in step S6. As shown in FIG. 6B, the output unit 66 displays on the PC that the rewriting of the MAC address table has been detected, and the name of the detected base station device 30 and the access line ID. Further, the output unit 66 displays a detection process re-execution button on the PC. When the administrator presses the start button by operating the PC, the detection device 60 re-executes the loop detection process.

  Thus, according to the present embodiment, the detection device 60 generates loop information indicating whether or not a loop has occurred based on the correspondence table included in the gateway device 20 connected to each switch device 40. Since the gateway device 20 is connected to each switch device 40, the correspondence table shows the relationship between all the switch devices 40 provided on the network and the base station device 30 connected to each switch device 40. Show. Thereby, the detection device 60 can detect a communication loop in the network without transmitting a test frame.

  Further, according to the present embodiment, if one faulty access line can be found, the detection device 60 can determine the location where a loop occurs in the same service area as the access line based on the ID of the access line. Detect automatically. As a result, the detection device 60 can significantly reduce the time taken to detect the location where the loop occurs.

  In addition, according to the present embodiment, the administrator of the communication system 1 can specify the location of the loop by inputting an arbitrary one line selection and program execution instruction to the detection device 60. Thereby, uniform detection accuracy can be realized regardless of the level of the skill of the administrator.

  Further, according to the present embodiment, the administrator of the communication system 1 can cause the detection device 60 to detect a loop portion by accessing the detection device 60 with a PC. As a result, the administrator can specify the location of the loop without installing a special environment or special program in the PC.

  Further, the detection device 60 according to the present embodiment operates with a simple mechanism that takes advantage of the characteristics of MAC address encapsulation. Therefore, the administrator of the communication system 1 can introduce the detection device 60 without making a large-scale capital investment.

<< Second Embodiment >>
The communication system 1 according to the second embodiment is different from the first embodiment in that the switch devices 40 may communicate with each other without using the gateway device 20.
In this case, a plurality of EoEMAC addresses may be frequently rewritten in the MAC address table of the gateway device 20. Hereinafter, a phenomenon in which a plurality of EoEMAC addresses are frequently rewritten will be described.

  When a communication loop occurs in the base station device 30, a frame transmitted from another base station device 30 is transmitted to the switch device 40 as an unknown unicast frame in the base station device 30. When the unknown unicast frame is transmitted to the switch device 40, the switch device 40 converts the unknown unicast frame into an EoE packet and transmits it to the relay network N by multicast.

FIG. 7 is a diagram illustrating an example of the behavior of the MAC address table of the gateway device 20 according to the second embodiment when a communication loop occurs.
As described above, the unknown unicast frame is generated by returning a frame transmitted from another base station apparatus 30. Therefore, the gateway device 20 has the same EoEMAC address associated with the MAC addresses of a plurality of other base station devices 30 in the MAC address table as shown in FIG. 7A, as shown in FIG. Is rewritten to the EoEMAC address of the switch device 40. Thereafter, when the gateway device 20 receives a frame from another base station device 30, the gateway device 20 receives the EoEMAC address associated with the MAC address of the switching facility 10 in the MAC address table as shown in FIG. Is rewritten to the EoEMAC address of the switch device 40 connected to the other base station device 30. By repeating this process, a plurality of EoEMAC addresses in the MAC address table of the gateway device 20 are frequently rewritten.

  Therefore, the detection unit 65 according to the second embodiment identifies the switch device 40 having the interface with the rewritten EoEMAC address, and a communication loop has occurred in the base station device 30 connected to the switch device 40. The base station device 30 is assumed.

FIG. 8 is a flowchart showing loop detection processing by the detection device 60 according to the second embodiment.
The acquiring unit 63 accesses the selected gateway device 20 and acquires the MAC address table a plurality of times (for example, three times) at different timings (step S1). When acquiring the MAC address table, the acquiring unit 63 records the MAC address table in the table storage unit 64.

  When the acquisition unit 63 acquires a plurality of MAC address tables, the detection unit 65 creates an address / accommodation correspondence table by merging the plurality of MAC address tables for each MAC address (step S2).

  Next, the detection unit 65 determines whether or not there is a correspondence table in which the EoEMAC address and the MAC address of the communication device have a many-to-one or many-to-many relationship (step S3). . If the detection unit 65 determines that there is no many-to-one or many-to-many relationship between the EoEMAC address and the MAC address of the communication device (step S3: NO), the base station device 30 makes a communication loop. Loop information indicating that no occurrence has occurred is generated (step S4).

  On the other hand, when it is determined that there is a many-to-one or many-to-many relationship between the EoEMAC address and the MAC address of the communication device (step S3: YES), the detection unit 65 determines the MAC address of the communication device. It is determined whether or not there is one indicating a local port of the gateway device 20 among the EoEMAC addresses in a many-to-one or many-to-many relationship (step S11). When the detection unit 65 determines that there is an EoEMAC address that indicates the local port of the gateway device 20 (step S11: YES), the detection unit 65 indicates an interface indicated by the EoEMAC address that is not the local port of the gateway device 20. The switch device 40 is identified as the switch device 40 connected to the communication device in which the communication loop has occurred (step S5).

  When the detection unit 65 determines that there is no EoEMAC address indicating the local port of the gateway device 20 (step S11: NO), there is a combination in which the EoEMAC address has a many-to-one or many-to-many relationship. It is determined whether or not there is a common EoEMAC address in the combination (step S12). When it is determined that a common EoEMAC address exists (step S12: YES), the detection unit 65 switches the switch device 40 having the interface indicated by the EoEMAC address to the communication device in which the communication loop has occurred. (Step S13).

  Next, the detection unit 65 identifies the base station device 30 that has a one-to-one correspondence with the EoEMAC address indicating the interface of the switch device 40 identified in step S5 or step S13 as the base station device 30 in which the communication loop has occurred. Then, loop information indicating the base station device 30 in which the communication loop has occurred is generated (step S6).

  On the other hand, when there is only one EoEMAC address in a many-to-one or many-to-many relationship, or when there is no common EoEMAC address (step S12: NO), the detection unit 65 sets the EoEMAC address to the EoEMAC address. Loop information indicating that a loop has occurred in any of the base station devices 30 indicated by the associated plurality of MAC addresses is generated (step S14).

  Then, the output unit 66 displays the loop information generated in step S4, step S6, or step S14 on the PC screen as a detection result (step S7).

  As described above, the detection device 60 according to the present embodiment can perform communication in the network without transmitting the test frame even when the switch devices 40 may communicate with each other without using the gateway device 20 in the communication system 1. Loops can be detected.

<< Third Embodiment >>
Next, a third embodiment will be described.
The detection device 60 according to the first and second embodiments detects a communication loop and presents it to the administrator. In contrast, after detecting a communication loop, the detection device 60 according to the third embodiment stops the switch device 40 connected to the base station device 30 in which the loop is generated.

  The detection device 60 according to the third embodiment further includes a switch stop unit (not shown) in addition to the configuration of the first embodiment. The switch stop unit stops the switch device 40 connected to the base station device 30 when the detection unit 65 generates loop information specifying the base station device 30 in which the loop is generated.

  The switch stop unit stops the switch device 40 when the administrator of the communication system 1 obtains the consent of the supervisor who monitors the failure of the mobile communication after the loop information is displayed in step S7. You may let them. In this case, the switch stop unit stops the switch device 40 when the administrator inputs a switch stop instruction to the detection device 60 using the PC.

  As described above, the embodiment has been described in detail with reference to the drawings. However, the specific configuration is not limited to that described above, and various design changes and the like can be made. For example, in the above-described embodiment, the case where the gateway device 20 and the switch device 40 have the EoE function has been described. For example, the gateway device 20 and the switch device 40 may use another technique for encapsulating the data link layer frame into a frame including the MAC address unique to the relay network N.

  Moreover, although embodiment mentioned above demonstrated the case where a MAC address was used as a transmission source address, it is not restricted to this. For example, in another embodiment, any other address may be used as the source address as long as the address can uniquely identify the external interface of the switch device 40 and the communication device connected to the interface.

The computer includes a CPU, a main storage device, an auxiliary storage device, and an interface.
The detection device 60 described above is mounted on a computer (not shown). The operation of each processing unit described above is stored in the auxiliary storage device in the form of a program. The CPU reads the program from the auxiliary storage device, develops it in the main storage device, and executes the above processing according to the program. In addition, the CPU secures a storage area corresponding to the table storage unit 64 in the main storage device according to the program.

  In at least one embodiment, the auxiliary storage device is an example of a tangible medium that is not temporary. Other examples of the tangible medium that is not temporary include a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, and a semiconductor memory connected via an interface. When this program is distributed to a computer via a communication line, the computer that has received the distribution may develop the program in a main storage device and execute the above-described processing.

  The program may be for realizing a part of the functions described above. Further, the program may be a so-called difference file (difference program) that realizes the above-described function in combination with another program already stored in the auxiliary storage device.

  DESCRIPTION OF SYMBOLS 1 ... Communication system 10 ... Exchange equipment 20 ... Gateway apparatus 30 ... Base station apparatus 40 ... Switch apparatus 50 ... Database apparatus 60 ... Detection apparatus 61 ... Input part 62 ... Selection part 63 ... Acquisition part 64 ... Table storage part 65 ... Detection part 66 ... Output unit M ... Terminal N ... Relay network

Claims (12)

A plurality of switch devices connected to the communication device;
A gateway device connected to each of the switch devices via the same network;
A detection device for detecting a communication loop in the communication device,
The gateway device is
Store the source address based on frames transmitted from multiple communication devices and switch devices,
The detection device includes:
An acquisition unit that acquires a correspondence table between a first transmission source address of the interface of the switch device and a second transmission source address of the interface of the communication device connected to the interface from the gateway device;
Based on said correspondence table, said first source address and said second correspondence between the transmission source address is many-to-one or many-to-many in such shall have when there exist a plurality of common in the relationship A communication system comprising: a detection unit that generates loop information indicating whether a communication loop has occurred in the communication device when a switch device having an interface with a first source address can be identified. The communication system according to claim 1, wherein the correspondence table is a correspondence table used by the gateway device for address resolution. The acquisition unit acquires the correspondence table from the gateway device multiple times at different timings,
The detection unit merges the plurality of correspondence tables for each second source address,
The communication system according to claim 1, wherein the loop information is generated based on a correspondence relationship between the first transmission source address and the second transmission source address after merging. The detection unit merges the correspondence table for each of the second transmission source addresses, and the second transmission source address corresponding to the first transmission source address after merging is a local port of the gateway device. When the source address of the connected communication device is the same, the switch device having the interface of the first source address is identified, and a communication loop has occurred in the communication device connected to the switch device. The communication system according to claim 3, wherein the communication system is a communication device. The detection unit merges the correspondence table for each second transmission source address, and the correspondence relationship between the first transmission source address and the second transmission source address after merging is many-to-one or many-to-many. In the case where there are a plurality of devices, the switch device having the interface of the first transmission source address that is common in the correspondence relationship is specified, and the communication device connected to the switch device is connected to the communication in which the communication loop has occurred. The communication system according to claim 3 or 4, wherein the communication system is a device. The communication system according to claim 4, wherein the detection unit sets a communication device connected to the identified switch device in a one-to-one relationship to a communication device in which a communication loop has occurred. The second transmission source address is an address used when a transmission source frame transmitted from the communication device is encapsulated with a transmission source frame in the network. The communication system according to 1. The second transmission source address is a transmission source address of the base station device,
The communication system according to any one of claims 1 to 7, wherein the detection unit detects a base station apparatus in which a communication loop has occurred. The second transmission source address is a transmission source address of the base station device,
The network includes a gateway device according to a communication type of the base station device,
The detection apparatus includes a selection unit that selects a gateway apparatus that acquires the correspondence table based on the input communication type of the base station apparatus.
The communication system according to any one of claims 1 to 8, wherein the detection unit acquires the correspondence table from a gateway device selected by the selection unit. The second transmission source address is a transmission source address of the base station device,
The network is provided for each service area and connected to a plurality of the base station devices,
The detection device includes a selection unit that selects a gateway device that acquires the correspondence table based on information indicating the input service area.
The communication system according to any one of claims 1 to 9, wherein the detection unit acquires the correspondence table from a gateway device selected by the selection unit. In a network connecting a plurality of switch devices connected to a communication device and a gateway device connected to each of the switch devices, a detection device for detecting a communication loop in the communication device,
An acquisition unit that acquires a correspondence table between a first transmission source address of the interface of the switch device and a second transmission source address of the interface of the communication device connected to the interface from the gateway device;
Based on said correspondence table, said first source address and said second correspondence between the transmission source address is many-to-one or many-to-many in such shall have when there exist a plurality of common in the relationship A detection device comprising: a detection unit that generates loop information indicating whether a communication loop has occurred in the communication device when a switch device having an interface with a first source address can be identified. In a network connecting a plurality of switch devices connected to a communication device and a gateway device connected to each of the switch devices, a method for detecting a communication loop in the communication device,
Obtaining a correspondence table between a first transmission source address of the interface of the switch device and a second transmission source address of the interface of the communication device connected to the interface from the gateway device;
Based on said correspondence table, said first source address and said second correspondence between the transmission source address is many-to-one or many-to-many in such shall have when there exist a plurality of common in the relationship And a detection step of generating loop information indicating whether or not a communication loop has occurred in the communication device when a switch device having an interface of a first source address can be identified.

Images