JP2014042098A - Network connection device, network control method, network control program, and network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately identify the location of a failure in a network.SOLUTION: A network connection device is connected with an opposite station network connection device via a first link and is connected with the own station maintenance endpoint node via a second link. The network connection device includes a first processing section and a second processing section. The first processing section transmits a first connectivity confirmation message to the opposite station network via the first link instead of the own station maintenance endpoint node when the second link is disconnected with detection of input failure of the first link. The second processing section transmits a second connectivity confirmation message to the own station maintenance endpoint node via the second link instead of the opposite station maintenance end point node when a third link between the opposite station network connection device and the opposite station maintenance endpoint node is disconnected with the detection of the input failure of the first link in the opposite station network connection device.

Description

  The present invention relates to a network connection device, a network control method, a network control program, and a network system.

  A link pass-through function is known as a function for maintaining communication continuity when a link down occurs in a network system that performs communication via a plurality of links (see, for example, Patent Document 1 and Patent Document 2). ). Link-down refers to a state in which link communication cannot be performed due to, for example, cable disconnection or equipment failure. Link pass-through is sometimes called link cross transfer, link interlocking, and the like.

Hereinafter, the link pass-through function will be described with reference to FIG. As shown in FIG. 14, in this network system, the two media converters 1 and 2 are connected via an optical fiber 3. Media converter 1 is UTP (Unshielded)
It is connected to a computer 5 via a Twist Pair cable. The media converter 2 is connected to the hub 7 via the UTP 6. The media converters 1 and 2 are assumed to have a link pass-through function.

  Here, for example, when the link down of UTP 4 is detected, the media converter 1 cuts the link of the optical fiber 3. Due to the link-down of the optical fiber 3, the media converter 2 forcibly disconnects the link of the UTP 6. Thereby, the hub 7 can detect a link down. On the other hand, for example, when a link down of the optical fiber 3 is detected, the media converters 1 and 2 forcibly disconnect the links of the UTPs 4 and 6. Thereby, the computer 5 and the hub 7 can each detect a link down.

  On the other hand, in recent years, Ethernet (registered trademark) has been used in a wide area network, and the importance of maintenance management has increased. Therefore, standardization of Ethernet OAM (Operations, Administration, Maintenance), which is a function for maintaining and managing Ethernet, is being promoted (for example, ITU-T recommendation Y.1731 and IEEE 802.1ag). In the above, ITU-T is an abbreviation for International Telecommunication Union Telecommunication Standardization Sector. IEEE is an abbreviation for Institute of Electrical and Electronic Engineers. Various maintenance management techniques using Ethernet OAM have been proposed (see, for example, Patent Document 3).

As one of typical failure detection functions in Ethernet OAM, connectivity check (CC: Continuity Check) can be cited. CC is a CCM (Continuity) that is an inspection frame from end to end of a switch group to be maintained and managed.
This is a function for confirming the connection by periodically sending (Check Message).

  Patent Document 4 describes a technique for quickly detecting a location where a link failure has occurred in a transmission system that performs data transmission by sequentially connecting a plurality of transmission apparatuses via a transmission line.

JP 2010-212762 A JP2012-100086A JP 2011-119916 A JP 2011-055381 A

  By the way, the media converter as shown in FIG. Therefore, the combined use of the link pass-through function and Ethernet OAM is expected.

  However, as described above, when a general media converter equipped with a link pass-through function finds a failure in one link, the other link itself is forcibly disconnected. In this case, although the failure has actually occurred only in the one-way link, the two-way link is disconnected. As a result, a bidirectional CCM failure occurs in the connectivity check of Ethernet OAM. Therefore, a device that manages Ethernet OAM determines that a failure has occurred in a bidirectional link even when a failure has occurred in a link in only one direction. That is, there is a case where correct failure determination may not be performed, which may hinder speeding up of failure recovery. In short, when the link pass-through function and the Ethernet OAM are used in combination, there is a possibility of fault recognition being wrong.

  The present invention has been made to solve the above-described problems, and provides a network connection device, a network control method, a network control program, and a network system that can more accurately identify a failure occurrence location in a network. The purpose is to do.

  The network connection device of the present invention is a network connection device that is connected to the opposite station network connection device via the first link and is connected to the local station maintenance end point node via the second link. When the second link is disconnected due to detection of an input failure, a first connectivity confirmation message is transmitted to the opposite station network connection device via the first link instead of the local station maintenance end point node. When the third link between the opposite station network connection device and the opposite station maintenance end point node is disconnected due to the input failure detection of the first link in the first station and the opposite station network connection device, the opposite A second processing unit for transmitting a second connectivity confirmation message to the local maintenance terminal node via the second link instead of the local maintenance terminal node , Comprising a.

  The network control method of the present invention is a network control method in a network connection device that is connected to a counter station network connection device via a first link and connected to a local station maintenance endpoint node via a second link, When the second link is disconnected due to the input failure detection of the first link, the first connectivity confirmation is made to the opposite station network connection device via the first link instead of the local station maintenance end point node. When the third link between the opposite station network connection device and the opposite station maintenance terminal node is disconnected due to the input failure detection of the first link in the opposite station network connection device when the message is transmitted, the opposite station In place of the maintenance end point node, a second connectivity confirmation message is transmitted to the local maintenance end point node via the second link. That.

  The network control program of the present invention is connected to the opposite link network connection device via the first link and to the first link on the computer of the network connection device connected to the local station maintenance terminal node via the second link. When the second link is disconnected due to detection of an input failure, a first connectivity confirmation message is transmitted to the opposite station network connection device via the first link instead of the local station maintenance end point node. When the third link between the opposite station network connection device and the opposite station maintenance endpoint node is disconnected in accordance with the first processing and the input failure detection of the first link in the opposite station network connection device, the opposite station Instead of the maintenance end point node, a second connectivity confirmation message is transmitted to the local maintenance end point node via the second link. A second process is executed.

  The network system of the present invention includes a counter station system including a counter station maintenance end point node, and a counter station network connection device connected to the counter station maintenance end point node via a third link; Connected to the opposite station network connection device via the first link and connected to the local station maintenance end point node via the second link, and the second link is disconnected upon detection of an input failure of the first link. When this is done, a first connectivity confirmation message is transmitted to the opposite station network connection device via the first link instead of the own station maintenance endpoint node, and the first link in the opposite station network connection device is transmitted. When the third link is disconnected due to the detection of an input failure of the local station, the local station maintenance terminal is passed through the second link instead of the opposite station maintenance endpoint node. Comprising a local station network connection device for transmitting a second connectivity check message to the end node, the local station system including, a.

  According to the present invention, it is possible to more accurately identify a failure occurrence location in a network.

It is a block diagram which shows the structural example of the network system which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structural example of a local station network connection apparatus. It is a flowchart which shows an example of operation | movement (CCM proxy transmission operation | movement to an optical port) of an electric side CCM control part. It is a flowchart which shows an example of operation | movement (CCM proxy transmission operation | movement to an electric port) of an optical side CCM control part. It is a figure for demonstrating the operation example of the whole network system when a link failure generate | occur | produces in the input of the optical port of the local station network connection apparatus concerning the 1st Embodiment of this invention. It is a figure for demonstrating the operation example of the whole network system when a link failure generate | occur | produces in the input of the optical port of the opposite station network connection apparatus concerning the 1st Embodiment of this invention. It is a format diagram of a CCM frame in the IEEE802.1ag standard. It is a table | surface which shows an example of a CCM transmission interval. It is a table | surface which shows an example of the various setting items set to each of the electric side CCM control part and the optical side CCM control part. It is a block diagram which shows the structural example of the network system which concerns on the 2nd Embodiment of this invention. It is a block diagram which shows the structural example of the network connection apparatus which concerns on the 3rd Embodiment of this invention. It is a block diagram which shows the structural example of the network connection apparatus which concerns on the 4th Embodiment of this invention. It is a block diagram which shows the structural example of the network control program memorize | stored in the memory shown in FIG. It is a figure for demonstrating a link pass through function.

[First Embodiment]
FIG. 1 is a block diagram showing a configuration example of a network system 10 according to the first embodiment of the present invention. The network system 10 includes a local station system 12, an opposite station system 14, and an Ethernet (registered trademark) OAM management device 16.

  The local station system 12 includes a local station network connection device 20, a local station hub 22, and a local station MEP24. MEP is an abbreviation for Maintenance group End Point or Maintenance Entity Group End Point. The own station hub 22 is connected to the electrical port of the own station network connection apparatus 20. The local station MEP 24 is connected to the local station hub 22.

  The opposite station system 14 includes an opposite station network connection device 30, an opposite station hub 32, and an opposite station MEP34. The opposite station hub 32 is connected to the electrical port of the opposite station network connection device 30. The opposite station MEP 34 is connected to the opposite station hub 32.

  The own station network connection device 20 and the opposite station network connection device 30 are connected via respective optical ports.

  Since the local station network connection device 20 and the opposite station network connection device 30 are devices that convert different media (light / electricity) as described above, the optical / telecommunications device or the media converter (simply a converter). Sometimes called.

  The network system 10 is a network corresponding to the Ethernet standard, and includes an Ethernet OAM function that is an Ethernet maintenance management function. In the following description, the IEEE 802.1ag standard will be described as an example of Ethernet OAM. Of course, the Ethernet OAM standard is not limited to the above standard, and may be another standard.

  In the network system 10, the local station MEP24 and the counter station MEP34 are set as maintenance management endpoints on the Ethernet OAM.

  The own station MEP 24 and the opposite station MEP 34 monitor whether or not communication is normally performed in the maintenance management section using the CC function of Ethernet OAM. Specifically, the local station MEP 24 and the opposite station MEP 34 generate CCM frames and transmit them to the counterpart MEP at predetermined time intervals. Then, the local station MEP 24 and the opposite station MEP 34 mutually confirm arrival of the CCM frame transmitted from the counterpart MEP. The own station MEP 24 and the opposite station MEP 34 transmit the arrival confirmation result of the CCM to the Ethernet OAM management device 16.

  The Ethernet OAM management device 16 manages the local station MEP 24 and the opposite station MEP 34. Typically, the Ethernet OAM management device 16 performs maintenance operation management in the maintenance management section based on the arrival confirmation result received from each MEP.

  The above configuration is merely an example. For example, in FIG. 1, the local station hub 22 is not an essential component. Therefore, the local station MEP 24 and the local station network connection apparatus 20 may be directly connected. Similarly, the opposite station hub 32 is not an essential component. Therefore, the opposite station MEP 34 and the opposite station network connection device 30 may be directly connected.

  FIG. 2 is a block diagram showing a configuration example of the local station network connection device 20 shown in FIG. The local network connection device 20 includes an optical port 50, an electrical port 52, a photoelectric / optical conversion unit 54, an electrical side interface unit 56, an electrical side switching unit 58, an optical side switching unit 60, and link pass-through control. Unit 62 and an opposite station link pass-through detection unit 64. Furthermore, the local station network connection device 20 includes an electrical side CCM control unit 70 (first processing unit) and an optical side CCM control unit 80 (second nest processing unit).

  The optical port 50 is connected to an optical port (not shown) of the opposite station network connection device 30 constituting the opposite station system 14 via an optical communication medium, for example, an optical fiber.

  The electrical port 52 is connected to the local station hub 22 constituting the local station system 12 via an electric communication medium, for example, UTP (Unshielded Twist Pair cable).

  The photoelectric / electric conversion unit 54 converts the optical signal input from the optical port 50 into an electrical signal and outputs the electrical signal, and converts the electrical signal input from the electrical port 52 into an optical signal and outputs the optical signal.

  The electrical-side interface unit 56 converts the electrical signal input from the photoelectric / electro-optic conversion unit 54 into an electrical signal in a format suitable for the electrical port 52, and adapts the electrical signal input from the electrical port 52 to the optical port 50. Convert to a form of electrical signal.

  The electrical switching unit 58 selects a signal to be output to the optical port 50 from either “main signal” or “proxy CCM”. The main signal is a signal starting from the local station MEP24 and includes at least CCM. The proxy CCM is a CCM that is output from the local station network connection device 20 (specifically, the electric side CCM control unit 70) as a proxy for the local station MEP 24 when link pass-through occurs in the local station system 12. is there.

  The optical side switching unit 60 selects a signal to be transmitted to the electrical port 52 from either “main signal” or “proxy CCM”. The main signal is a signal starting from the opposite station MEP34 and includes at least CCM. The proxy CCM is a CCM output from the local station network connection device (specifically, the optical-side CCM control unit 80) as a starting point on behalf of the counter station MEP 34 when a link pass-through occurs in the counter station system 14. .

  The link pass-through control unit 62 controls link pass-through processing on the local station system 12 side. Specifically, the link pass-through control unit 62 investigates whether an input link failure has occurred in the optical port 50. When the link pass-through control unit 62 recognizes the occurrence of the input link failure of the optical port 50, the link pass-through control unit 62 issues an instruction to forcibly disconnect the link of the electrical port 52 to the electrical side interface unit 56. Then, the link pass-through control unit 62 transmits information indicating that the link pass-through process has been executed in the local station system 12 to the electrical CCM control unit 70.

  The opposite station link pass-through detection unit 64 investigates whether or not a link pass-through process accompanying an optical port input link failure is being executed in the opposite station system 14. When the opposite station link pass-through detection unit 64 recognizes the execution of the link pass-through process associated with the optical port input link failure in the opposite station system 14, the opposite station link pass-through detection unit 64 transmits the fact to the optical-side CCM control unit 80.

  The electrical-side CCM control unit 70 transmits the CCM to the opposite station MEP 34 on behalf of the local station MEP 24 when the link pass-through process is executed on the local station system 12 side. The electric side CCM control unit 70 includes an electric side CCM storage unit 72, an electric side CCM transmission unit 74, and an electric side CCM transmission control unit 76.

  The electrical CCM storage unit 72 detects and stores the CCM from the main signal input from the electrical port 52. The electric side CCM transmission unit 74 processes the CCM read from the electric side CCM storage unit 72 into preset contents and outputs the processed contents to the optical port 50. When the electrical side CCM transmission control unit 76 recognizes the occurrence of the link pass-through process, the electrical-side CCM transmission control unit 76 executes the CCM transmission process acting on behalf of the local station MEP24.

  When the link pass-through process is executed on the opposite station system 14 side, the optical-side CCM control unit 80 transmits the CCM to the own station MEP 24 on behalf of the opposite station MEP 34. The optical side CCM control unit 80 includes an optical side CCM storage unit 82, an optical side CCM transmission unit 84, and an optical side CCM transmission control unit 86.

  The optical-side CCM storage unit 82 detects the CCM from the main signal input from the electrical port 52, analyzes and stores it. The optical-side CCM transmission unit 84 processes the CCM read from the optical-side CCM storage unit 82 into preset content and outputs it to the electrical port 52. When the optical-side CCM transmission control unit 86 recognizes the occurrence of the link pass-through process, the optical-side CCM transmission control unit 86 executes the CCM transmission process acting on behalf of the opposite station MEP34.

  For detecting the input link failure of the optical port 50 in the local station network connection apparatus 20 and detecting the execution of the link pass-through process accompanying the optical port input link failure in the opposite station system 14, a known technique can be used. it can. As an example of a known technique, for example, a technique described in TS-1000 defined by the Information and Communication Technology Committee can be given.

  Next, the operation of the network system 10 according to the first embodiment will be described.

  FIG. 9 referred to in the following description is a table showing an example of various setting items set in each of the electric side CCM control unit 70 and the optical side CCM control unit 80. In FIG. Items 1 to 3 are items set in the electrical-side CCM control unit 70. In FIG. Items 4 to 6 are items set in the optical-side CCM control unit 80.

  First, the detailed operation of the local station network connection device 20 constituting the network system 10 will be described. As the premise of the following description, both CCM proxy transmission to the optical port 50 (see No. 1 in FIG. 9) and CCM proxy transmission to the electrical port 52 (see No. 4 in FIG. 9) are both “valid”. It is assumed that it is set to.

  First, the operation of the electric side CCM control unit 70 will be described.

  During normal operation, when the CCM storage unit 72 detects a CCM from the main signal input from the electrical port 52, the electrical CCM storage unit 72 stores the CCM for a predetermined period (see, for example, No. 2 in FIG. 9).

  FIG. 3 is a flowchart illustrating an example of the operation of the electric side CCM control unit 70 (the CCM proxy transmission operation to the optical port 50). The link pass-through control unit 62 investigates whether an input link failure has occurred in the optical port 50 (step S100). When a link failure occurs at the input of the optical port 50 (Yes in step S100), the link pass-through control unit 62 forcibly disconnects the link of the electrical port 52 (step S101). The link pass-through control unit 62 notifies the electric-side CCM transmission control unit 76 that the local network connection device 20 is executing link pass-through.

  When the local station is performing link pass-through and the CCM is stored in the electrical CCM storage unit 72, the electrical CCM transmission control unit 76 instructs the electrical CCM transmission unit 74 to perform CCM transmission. The electrical side CCM transmission unit 74 controls the electrical side switching unit 58 to switch the output signal path to the optical port 50 from the electrical port 52 side to the electrical side CCM transmission unit 74 side (step S102). The electrical-side CCM transmission unit 74 reads out the CCM stored in the electrical-side CCM storage unit 72 and processes it according to preset contents (step S103).

  FIG. 7 shows a format diagram of a CCM frame in the IEEE 802.1ag standard. For example, among the various items, the electrical-side CCM transmission unit 74 sets the received CCM value as it is to items other than SA (Source Address) and RDI (Remote Defect Indication). In the SA, a MAC (Media Access Control address) address of the local network connection device 20 is set. In RDI, for example, No. 1 in FIG. The value specified in 3 is set. Note that ITU-T Y.T. For the 1731 CCM, the same measures as described above can be performed. By the way, the electrical-side CCM storage unit 72 determines whether or not the received frame is a CCM based on the TYPE value and the OpCode value.

  Returning to the description of FIG. 3, the electrical-side CCM transmission unit 74 performs proxy transmission of the CCM processed as described above toward the optical port at an interval indicated by the value of CCM Interval (see FIG. 7) (step S104). . FIG. 8 shows a setting example of CCM Interval.

  The electrical-side CCM transmission control unit 76 investigates whether or not the link pass-through process is being executed in the local station network connection device 20 (step S105). If it is being executed (Yes determination in step S105), the CCM proxy transmission by the electrical CCM transmission unit 74 is continuously performed. If it is not being executed (No determination in step S105), the CCM proxy transmission by the electrical-side CCM transmission unit 74 ends.

  Next, the operation of the light side CCM control unit 80 will be described.

  During normal operation, when detecting the CCM from the main signal input from the optical port 50, the optical-side CCM storage unit 82 stores the CCM for a predetermined period (for example, refer to No. 5 in FIG. 9).

  FIG. 4 is a flowchart showing an example of the operation of the optical-side CCM control unit 80 (CCM proxy transmission operation to the electrical port 52). The opposite station link pass-through detection unit 64 investigates whether or not the link pass-through process is executed due to the optical port input link failure in the opposite station system 14 (step S200). When the link pass-through process is executed in the opposite station system 14 (Yes in step S200), the opposite station link pass-through detection unit 64 indicates that the opposite station network connection device 30 is executing the link pass-through and transmits the optical side CCM. The control unit 86 is notified. The link pass-through process in the opposite station network connection device 30 is specifically a process in which the link of the electrical port in the opposite station network connection device 30 (link with the opposite station hub 32) is forcibly disconnected.

  When the opposite station is executing link pass-through and the CCM is stored in the optical CCM storage unit 82, the optical CCM transmission controller 86 instructs the optical CCM transmission unit 82 to perform CCM transmission. The optical side CCM transmission unit 82 controls the optical side switching unit 60 to switch the output signal path to the electrical port 52 from the optical port 50 side to the optical side CCM transmission unit 84 side (step S201). The optical-side CCM transmission unit 84 reads out the CCM stored in the optical-side CCM storage unit 82 and processes it according to preset contents (step S202). The CCM processing in the optical CCM transmission unit 84 is the same as the above-described processing method of the electrical CCM transmission unit 84, and thus description thereof is omitted here. In the CCM processing in the optical-side CCM transmission unit 84, RDI includes, for example, No. in FIG. The value specified in 6 is set.

  The optical-side CCM transmission unit 84 performs proxy transmission of the CCM processed as described above toward the electrical port 52 at intervals indicated by the value of CCM Interval (see FIG. 7) (step S203).

  The optical-side CCM transmission control unit 86 investigates whether or not the link pass-through process is being executed in the opposite station network connection device 30 (step S204). If it is being executed (Yes in step S204), the CCM proxy transmission by the optical CCM transmission unit 84 is continuously performed. If it is not being executed (No determination in step S204), the CCM proxy transmission by the optical CCM transmission unit 84 ends.

  Next, the operation of the entire network system 10 ((1) to (3) shown below) will be described.

(1) Description of operation during normal operation During normal operation, between the opposite station MEP34 and the local station MEP24 (section shown as "CCM delivery section during normal operation" in FIG. 1), CCM as a function of Ethernet OAM Transmission / reception is taking place. When the electrical-side CCM storage unit 72 constituting the local network connection device 20 detects a CCM from the main signal input from the electrical port 52, the electrical-side CCM storage unit 72 stores the CCM. When the optical-side CCM storage unit 82 constituting the local network connection device 20 detects a CCM from the main signal input from the optical port 50, the optical-side CCM storage unit 82 stores the CCM.

(2) Explanation of Operation when Link Failure Occurs at Input of Optical Port 50 of Local Station Network Connection Device 20 FIG. 5 is a block diagram showing a configuration example of the network system 10 and 3 is a diagram for explaining an operation example of the network system 10 when a link failure occurs at the input of the optical port 50. FIG.

  First, it is assumed that a link failure has occurred at the input of the optical port 50 of the local station network connection apparatus 20 for some reason (step S1). The link of the electrical port 52 is forcibly disconnected by the activation of the link pass-through function of the local station network connection device 20 (step S2). In this state, the CCM output from the local station MEP 24 does not reach the opposite station MEP 34. That is, the CCM cannot be delivered in the “CCM delivery section during normal operation” shown in FIG.

  Therefore, the local station network connection device 20 reads out the CCM stored before the forcible disconnection of the electrical port 52 due to the occurrence of the input link failure of the optical port 50), performs desired processing, and performs a predetermined process from the optical port 50 at a predetermined interval. Output continuously (step S3). As a result, the opposite station MEP 34 can continuously receive the CCM. The CCM is delivered in the “CCM proxy delivery section” shown in FIG. As understood from the above description, the “CCM proxy delivery section” is a section between the opposite station MEP 34 and the local station network connection device 20.

  Due to the forced link disconnection (step S2), the CCM from the opposite station MEP34 does not reach the local station MEP24. Accordingly, the local station MEP 24 detects LOC (Loss Of Continuity) indicating CCM disruption, that is, loss of continuity. The local station MEP 24 notifies the Ethernet OAM management device 16 of “LOC occurrence” (step S4).

  On the other hand, since the opposite MEP 34 continues to receive CCM by the CCM proxy transmission (step S3), LOC does not occur. The opposite MEP 34 notifies the Ethernet OAM management device 16 of “No LOC”.

  As a result, the Ethernet OAM management device 16 may recognize that a failure has occurred in the direction of the opposite station MEP34 → the local station MEP24, but no failure has occurred in the direction of the local station MEP24 → the opposite station MEP34. it can.

  When troubleshooting is performed based on the above recognition of the Ethernet OAM management device 16 and the link failure of the optical port 50 input is removed, the forced link disconnection (step S2) of the electrical port 52 performed by the link pass-through function is canceled. The Then, the local station network connection device 20 stops the CCM proxy transmission to the optical port 50 and restores the communication between the optical port 50 and the electrical port 52. As a result, the network system 10 enters the above-described “normal operation” operating state.

(3) Explanation of Operation when Link Failure Occurs in Input of Optical Port of Opposite Station Network Connection Device 30 FIG. 6 is a block diagram showing a configuration example of the network system 10 and also shows the optical of the opposite station network connection device 30 It is a figure for demonstrating the operation example of the whole network system 10 when a link failure generate | occur | produces in the input of a port.

  First, it is assumed that a link failure has occurred in the input of the optical port of the opposite station network connection device 30 for some reason (step S10). By the activation of the link pass-through function of the opposite station network connection device 30, the link of the electrical port of the opposite station network connection device 30 is forcibly disconnected (step S11). In this state, the CCM output from the opposite station MEP34 does not reach the local station MEP24. That is, the CCM cannot be delivered in the “CCM delivery section during normal operation” shown in FIG.

  Therefore, the local station network connection device 20 reads out the CCM stored before the forced link disconnection of the electrical port due to the occurrence of the input link failure of the optical port in the opposite station network connection device 30, performs the desired processing, and performs the desired processing from the electrical port 52. The data is continuously output at a predetermined interval (step S12). As a result, the local station MEP 24 can continuously receive the CCM. The CCM is delivered in the “CCM proxy delivery section” shown in FIG. The “CCM proxy delivery section” is a section between the local station MEP 24 and the local station network connection apparatus 20 as understood from the above description.

  Due to the forced link disconnection (step S11), the CCM originating from the local station MEP24 does not reach the opposite station MEP34. Therefore, the opposite station MEP 34 detects LOC (Loss Of Continuity) indicating CCM interruption, that is, loss of continuity. The opposite station MEP 34 notifies the Ethernet OAM management device 16 of “LOC occurrence” (step S13).

  On the other hand, the local station MEP 24 continues to receive the CCM by the CCM proxy transmission (step S12), and therefore no LOC occurs. The local station MEP 24 notifies the Ethernet OAM management device 16 of “No LOC”.

  As a result, the Ethernet OAM management device 16 may recognize that a failure has occurred in the direction of the local station MEP24 → the opposite station MEP34, but no failure has occurred in the direction of the opposite station MEP34 → the local station MEP24. it can.

  When troubleshooting is performed based on the above recognition of the Ethernet OAM management device 16 and the link failure of the optical port 50 input is removed, the forced link disconnection of the electrical port of the opposite station network connection device 30 implemented by the link pass-through function ( Step S11) is canceled. Then, the local station network connection device 20 stops the CCM proxy transmission to the electrical port 52 and restores the communication between the optical port 50 and the electrical port 52. As a result, the network system 10 enters the above-described “normal operation” operating state.

  As described above, the local station network connection device 20 according to the first embodiment acts as a proxy for the MEP on the side where the link pass-through has occurred even when the link pass-through is executed on the local station side or the opposite station side. Then, the CCM is transmitted to the MEP on the opposite side. Therefore, as described above, the Ethernet OAM management device 16 can determine in which direction of the link the failure has occurred.

That is, according to the first embodiment described above, it is possible to accurately identify the location where a failure has occurred in the network even when the link pass-through function and the Ethernet OAM are used together. Therefore, the speed of failure recovery can be increased.
[Second Embodiment]
FIG. 10 is a block diagram showing a configuration example of the network system 100 according to the second embodiment of the present invention. The network system 100 includes a local station system 102, an opposite station system 104, and an Ethernet OAM management device 16. The difference in configuration between the network system 100 shown in FIG. 10 and the network system 10 shown in FIG. 1 is that CCMs sent from a plurality of MEPs pass through the local network connection device 150. . Specifically, the first pair of the first local station MEP 152 and the first opposite station MEP 160 performs CCM transmission / reception in the first CCM delivery section during normal operation. Further, the second pair consisting of the second own station MEP 154 and the second opposite station MEP 162 performs CCM transmission / reception in the second CCM delivery section during normal operation.

  Furthermore, CCM proxy transmission is also performed for each pair. When link link pass-through is executed on the local network connection device 150 side for the first pair, the local network connection device 150 transmits the CCM to the first opposite station MEP 160 on behalf of the first local station MEP 152. On the other hand, when the link pass-through is executed on the opposite station network connection apparatus 30 side, the own station network connection apparatus 150 transmits the CCM to the first own station MEP 152 on behalf of the first opposite station MEP 160.

  When link link pass-through is executed on the local network connection device 150 side with respect to the second pair, the local network connection device 150 transmits the CCM to the second opposite station MEP 162 on behalf of the second local station MEP 154. On the other hand, when link pass-through is executed on the opposite station network connection apparatus 30 side, the own station network connection apparatus 150 transmits the CCM to the second own station MEP 154 on behalf of the second opposite station MEP 162.

  Each MEP, each hub, the opposite station network connection device 30, and the Ethernet OAM management device 16 shown in FIG. 10 have functions equivalent to the corresponding elements shown in FIG. Therefore, those descriptions are omitted.

  The electrical-side CCM storage unit 72 and the optical-side CCM storage unit 82 constituting the local station network connection apparatus 150 store a plurality of types of CCMs so that they can be identified. Here, the plurality of types of CCMs means a first pair CCM and a second pair CCM. Further, in relation to the above, the local network connection apparatus 150 can set a predetermined setting value (for example, a setting value as shown in FIG. 9) for each pair of CCMs.

  With the configuration of the second embodiment described above, even when the link pass-through function and the Ethernet OAM are used together in a network system in which a plurality of MEP pairs exist, it is possible to accurately identify the location where a failure has occurred in the network. It becomes possible.

  In the second embodiment described above, the case where there are two MEP pairs has been described as an example, but there may be three or more MEP pairs. In that case, the local station network connection device 150 may be configured so that each CCM of three or more MEP pairs can be individually transmitted by proxy.

In the first and second embodiments described above, IEEE 802.1ag has been described as an example of the Ethernet OAM standard, but the Ethernet OAM standard is, for example, ITU-T Recommendation Y. 1731 or a standard equivalent to these.
[Third Embodiment]
FIG. 11 is a block diagram showing a configuration example of the network connection apparatus 200 according to the third embodiment of the present invention. The network connection device 200 is connected to the opposite station network connection device (not shown) via the first link and to the own station maintenance end point node (not shown) via the second link. The network connection device 200 includes a first processing unit 202 and a second processing unit 204.

  When the second link is disconnected due to the input failure detection of the first link, the first processing unit 202 performs the first connection to the opposite station network connection device via the first link instead of the local station maintenance end point node. Send a sex confirmation message.

  The second processing unit 204 disconnects the third link (not shown) between the opposite station network connection device and the opposite station maintenance end point node (not shown) when the input failure of the first link in the opposite station network connection device is detected. Then, instead of the opposite station maintenance end point node, a second connectivity confirmation message is transmitted to the own station maintenance end point node via the second link.

  According to the third embodiment described above, even if the other link is forcibly disconnected when a failure of one link is detected, the connectivity confirmation message is interrupted in the direction where the failure does not originally occur. Sent without Therefore, it is possible to more accurately identify the location of the network failure.

[Fourth Embodiment]
FIG. 12 is a block diagram illustrating a configuration example of the network connection apparatus 300 according to the fourth embodiment of the present invention.

  The network connection device 300 includes a CPU (Central Processing Unit) 302 and a memory 304. The memory 304 stores the network control program 400. The CPU 302 executes the network control program 400. Examples of the memory 304 include a ROM (Read Only Memory), a hard disk, a removable medium, and a removable disk.

  FIG. 13 is a diagram for explaining the configuration of the network control program 400. The network control program 400 includes a first program 402 and a second program 404.

  The first program 402 is a group of instructions for executing the processing shown in steps S100 to S105 in FIG. The second program 404 is a group of instructions for executing the processing shown in steps S200 to S204 in FIG.

  According to the fourth embodiment described above, even if the other link is forcibly disconnected when a failure of one link is detected, the connectivity confirmation message is interrupted in the direction where the failure does not originally occur. Sent without Therefore, it is possible to more accurately identify the location of the network failure.

10 network system 12 own station system 14 opposite station system 16 Ethernet OAM management device 20 own station network connection device 22 own station hub 24 own station MEP
30 Opposite station network connection device 32 Opposite station hub 34 Opposite station MEP
50 Optical Port 52 Electrical Port 54 Photoelectric / Electronic Conversion Unit 56 Electrical Side Interface Unit 58 Electrical Side Switching Unit 60 Optical Side Switching Unit 62 Link Pass Through Control Unit 64 Opposite Station Link Pass Through Detection Unit 70 Electrical Side CCM Control Unit 72 Electrical Side CCM Storage Unit 74 electrical side CCM transmission unit 76 electrical side CCM transmission control unit 80 optical side CCM control unit 82 optical side CCM storage unit 84 optical side CCM transmission unit 86 optical side CCM transmission control unit 100 network system 102 own station system 104 opposite station system 150 Local network connection device 152 First local station MEP
154 Second local station MEP
160 First Counter Station MEP
162 Second counter station MEP
200 Network Connection Device 202 First Processing Unit 204 Second Processing Unit 300 Network Connection Device 302 CPU
304 Memory 400 Network Control Program 402 First Program 404 Second Program

Claims (10)

A network connection device connected to the opposite station network connection device via the first link and connected to the local station maintenance end point node via the second link,
When the second link is disconnected due to the input failure detection of the first link, the first connectivity confirmation is made to the opposite station network connection device via the first link instead of the local station maintenance end point node. A first processing unit for transmitting a message;
When the third link between the opposite station network connection device and the opposite station maintenance end point node is disconnected due to the input failure detection of the first link in the opposite station network connection device, it replaces the opposite station maintenance end point node. A second processing unit that transmits a second connectivity confirmation message to the local maintenance node via the second link;
A network connection device comprising:   The first processing unit detects and stores the first connectivity confirmation message before disconnecting the second link, and reads the stored first connectivity confirmation message after disconnecting the second link. The network connection apparatus according to claim 1, wherein the network connection apparatus transmits to the opposite station network connection apparatus.   The first processing unit repeatedly transmits the saved first connection confirmation message to the opposite station network connection device at a predetermined period until the disconnection of the second link is released. The network connection device according to claim 2.   The second processing unit detects and stores the second connectivity confirmation message before disconnecting the third link, and reads the stored second connectivity confirmation message after disconnecting the third link. The network connection device according to any one of claims 1 to 3, wherein the network connection device transmits the information to a local maintenance node node.   The second processing unit repeatedly transmits the stored second connection confirmation message to the local maintenance node in a predetermined cycle until the disconnection of the third link is released. The network connection device according to claim 4.   6. The network connection according to claim 1, wherein the connectivity confirmation message is an Ethernet (registered trademark) OAM (Operations, Administration, Maintenance) standard CC (Continuity Check) message. apparatus.   The network connection device according to any one of claims 1 to 6, wherein the disconnection of the second link and the disconnection of the third link are forced disconnections associated with activation of a link pass-through function. A network control method in a network connection device that is connected to a counter station network connection device via a first link and connected to a local station maintenance endpoint node via a second link,
When the second link is disconnected due to the input failure detection of the first link, the first connectivity confirmation is made to the opposite station network connection device via the first link instead of the local station maintenance end point node. Send a message,
When the third link between the opposite station network connection device and the opposite station maintenance end point node is disconnected due to the input failure detection of the first link in the opposite station network connection device, it replaces the opposite station maintenance end point node. , Sending a second connectivity confirmation message to the local maintenance terminal node via the second link,
A control method characterized by that. To the computer of the network connection device connected to the opposite station network connection device via the first link and connected to the local station maintenance node via the second link,
When the second link is disconnected due to the input failure detection of the first link, the first connectivity confirmation is made to the opposite station network connection device via the first link instead of the local station maintenance end point node. A first process for sending a message;
When the third link between the opposite station network connection device and the opposite station maintenance end point node is disconnected due to the input failure detection of the first link in the opposite station network connection device, it replaces the opposite station maintenance end point node. A second process for transmitting a second connectivity confirmation message to the local maintenance node via the second link;
A network control program characterized in that A counter station system comprising: a counter station maintenance endpoint node; and a counter station network connection device connected to the counter station maintenance endpoint node via a third link;
Connected to the own station maintenance end point node via the first link and the opposite station network connection device and connected to the own station maintenance end point node via the second link, along with detection of an input failure on the first link When the second link is disconnected, a first connectivity confirmation message is transmitted to the opposite station network connection device via the first link instead of the local station maintenance endpoint node, and the opposite station network connection is established. When the third link is disconnected due to the input failure detection of the first link in the apparatus, the second connection is made to the local station maintenance end point node via the second link instead of the opposite station maintenance end point node. A local station system including a local station network connection device that transmits a confirmation message;
A network system comprising:

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