JP2015012346A - Network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network system in which a network administrator can easily grasp the state of an optical transmission device arranged on a user network side with less labor and effort.SOLUTION: A network system includes a switch 1 having a plurality of ports 1a, 1b, 1c and a plurality of optical transmission devices 2a, 2b, 2c having user ports 2a2, 2b2, 2c2 and long-distance ports 2a1, 2b1, 2c1. The ports 1a, 1b, 1c of the switch 1 are connected to the long-distance ports 2a1, 2b1, 2c1 of the optical transmission devices 2a, 2b, 2c, respectively. Each of the optical transmission devices 2a, 2b, 2c, when detecting occurrence of a fault, transmits connectivity confirmation information including fault information to the switch 1, and the switch 1 holds the fault information.

Description

  The present invention relates to a network system.

  As a function of maintenance operation of Ethernet (registered trademark), ITU-T Y. 1731 and IEEE802.1ag standardize Ethernet Operation Administration and Maintenance (OAM).

  As a conventional technique, for example, in Patent Document 1, two media converters (optical transmission apparatuses) mutually transmit Ethernet OAM CCM (Continuity Check Message) frames to the other party, and communication connectivity between each other Techniques for monitoring are disclosed.

JP 2012-120073 A

  FIG. 8 shows a schematic configuration of a network system using a conventional optical transmission apparatus.

  In FIG. 8, the switch 81 and the optical transmission devices 82d, 82e, and 82f are accommodated in the communication company station 83, and the ports 81a, 81b, and 81c of the switch 81 are users of the optical transmission devices 82d, 82e, and 82f, respectively. The ports 82d2, 82e2, and 82f2 are connected by communication cables. A port 81 d of the switch 81 is connected to the wide area network 84.

  The long-distance ports 82d1, 82e1, and 82f1 of the optical transmission devices 82d, 82e, and 82f are respectively connected to the long-distance ports 82a1, 82b1, and 82c1 of the optical transmission devices 82a, 82b, and 82c by communication cables. User ports 82a2, 82b2, and 82c2 of the optical transmission devices 82a, 82b, and 82c are connected to user networks 85a, 85b, and 85c, respectively.

  As shown in FIG. 8, conventionally, a configuration in which an optical transmission device arranged on the user network side and an optical transmission device arranged on the wide area network side are connected to face each other in a one-to-one manner is common.

  In FIG. 8, the optical transmission devices 82d, 82e, and 82f and the optical transmission devices 82a, 82b, and 82c that are connected to each other transmit a CCM frame to each other, and monitor the communication connectivity between them. . The network administrator connects the management terminal to the optical transmission devices 82d, 82e, and 82f on the wide area network side, and the contents of the CCM frame from the optical transmission devices 82a, 82b, and 82c received by the optical transmission devices 82d, 82e, and 82f. , The status of the optical transmission devices 82a, 82b, and 82c on the user network side is grasped.

  In such a prior art configuration, a network administrator must connect a management terminal to each of the optical transmission devices 82d, 82e, and 82f in order to grasp the status of the optical transmission devices 82a, 82b, and 82c. There was a problem. Such work is time-consuming for the network administrator.

  Accordingly, an object of the present invention is to provide a network system that can easily grasp the state of an optical transmission apparatus with little effort.

  To achieve the above object, the present invention includes a switch having a plurality of ports, forwarding a frame between the plurality of ports, a user port and a long-distance port, and a frame between the user port and the long-distance port. A plurality of optical transmission devices for transfer, each port of the plurality of ports of the switch is connected to a long-distance port of each optical transmission device of the plurality of optical transmission devices, and each optical transmission device detects the occurrence of a failure In this case, a network system is provided in which connectivity confirmation information including failure information is transmitted to the switch, and the switch holds the failure information.

  According to the network system of the present invention, it is possible to easily grasp the state of the optical transmission apparatus with little effort.

It is a figure which shows schematic structure of the network system which concerns on embodiment of this invention. It is a figure which shows schematic structure of the switch which concerns on embodiment of this invention. It is a figure which shows schematic structure of the optical transmission apparatus which concerns on embodiment of this invention. It is a figure which shows the structural example of a CCM frame roughly. It is a figure which shows the detailed structure of the Optional TLVs area | region contained in a CCM frame. It is a figure which shows the operation | movement which transmits a CCM frame in the network system which concerns on embodiment of this invention. It is a figure which shows the operation | movement which an optical transmission apparatus notifies generation | occurrence | production of a power failure to a switch in the network system which concerns on embodiment of this invention. It is a figure which shows schematic structure of the network system using the conventional optical transmission apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment]
[Network system]
FIG. 1 is a diagram showing a schematic configuration of a network system according to an embodiment of the present invention.

  In FIG. 1, a switch 1 is accommodated in a communication company station 3, and a port 1 d of the switch 1 is connected to a wide area network 4. The ports 1a, 1b, and 1c of the switch 1 are connected to the long-distance ports 2a1, 2b1, and 2c1 of the optical transmission devices 2a, 2b, and 2c arranged on the user networks 5a, 5b, and 5c side by communication cables, respectively. User ports 2a2, 2b2, and 2c2 of the optical transmission devices 2a, 2b, and 2c are connected to user networks 5a, 5b, and 5c, respectively.

  As described above, in the network system according to the present embodiment, the optical transmission device arranged on the user network side is not connected to the optical transmission device arranged on the wide area network side, but is switched to the switch arranged on the wide area network side. It differs from the prior art configuration in that it is directly connected.

[switch]
FIG. 2 is a diagram showing a schematic configuration of the switch according to the present embodiment.

  In FIG. 2, the switch 1 includes a plurality of ports 1 a, 1 b, 1 c, 1 d, a frame transfer control unit 6, and an OAM processing unit 7. In the present embodiment, the switch 1 is an L2 switch that performs a Layer2 (L2) process. The switch 1 may have a function of performing Layer 3 processing.

  The plurality of ports 1a, 1b, 1c, and 1d send frames received from the outside to the frame transfer control unit 6 and send frames sent from the frame transfer control unit 6 to the outside. Although four ports are illustrated in FIG. 2, the number of ports is not limited to this.

  The frame transfer control unit 6 performs control to transfer a frame between a plurality of ports. The operation for controlling frame transfer is the same as that of the conventional L2 switch. Specifically, the frame transfer control unit 6 includes an FDB (Forwarding Database) that stores the MAC address and the port in association with each other, refers to the destination MAC address of the MAC frame (frame), and associates the FDB with the destination MAC address. The stored port is determined as the transfer destination port, and the MAC frame is transferred to the port. Further, the frame transfer control unit 6 refers to the source MAC address of the MAC frame and associates the source MAC address with the port that received the MAC frame and registers them in the FDB.

  When an Ethernet OAM CCM frame is sent from a port, the frame transfer control unit 6 sends the CCM frame to the OAM processing unit 7. In addition, when a CCM frame is sent from the OAM processing unit 7, the frame transfer control unit 6 transfers the CCM frame to a predetermined port (a port to which the opposite device is connected).

  The OAM processing unit 7 performs Ethernet OAM processing. As a CC function of Ethernet OAM, the OAM processing unit 7 confirms reception of the CCM frame transmitted by the opposite device, and holds the reception status of the CCM frame (whether the CCM frame is received) (predetermined storage unit) To remember). When the OAM processing unit 7 does not receive a CCM frame for a predetermined time, the OAM processing unit 7 detects that a failure has occurred in communication with the opposite apparatus. Further, when failure information is included in the CCM frame transmitted by the opposite device, the OAM processing unit 7 holds the failure information (stores it in a predetermined storage unit). In addition, the OAM processing unit 7 generates CCM frames at predetermined time intervals and sends them to the frame transfer control unit 6 so as to transmit them to the opposite device. Further, when detecting the occurrence of a failure, the OAM processing unit 7 generates a CCM frame including failure information and transmits it to the opposite device.

[Optical transmission equipment]
FIG. 3 is a diagram showing a schematic configuration of the optical transmission apparatus 2a according to the present embodiment. The optical transmission devices 2b and 2c have the same configuration.

  In FIG. 3, the optical transmission device 2 a includes a long-distance port 2 a 1, a user port 2 a 2, a frame transfer unit 8, and an OAM processing unit 9.

  The long distance port 2a1 is a port to which a communication cable for transmitting a long distance (several kilometers to several hundred kilometers), for example, a single mode optical fiber is connected. The network on the long-distance port 2a1 side follows a long-distance standard such as Ethernet or a long-distance standard.

  The user port 2a2 is a port to which a communication cable having a shorter distance (several meters to several hundreds of meters) than the long-distance port 2a1, such as a metal cable or a multimode optical fiber, is connected. The network on the user port 2a2 side complies with a relatively short distance standard such as Ethernet.

  The frame transfer unit 8 converts the frame received at the long-distance port 2a1 into a signal conforming to the network standard on the user port 2a2 side, and transfers the signal to the user port 2a2. The frame transfer unit 8 converts the frame received at the user port 2a2 into a signal conforming to the network standard on the long distance port 2a1 side and transfers the signal to the long distance port 2a1.

  When the Ethernet OAM CCM frame is sent from the long distance port 2 a 1, the frame transfer unit 8 sends the CCM frame to the OAM processing unit 9. Further, when a CCM frame is sent from the OAM processing unit 9, the frame transfer unit 8 transfers the CCM frame to the long distance port 2a1.

  The OAM processing unit 9 performs Ethernet OAM processing. As a CC function of Ethernet OAM, the OAM processing unit 9 confirms reception of the CCM frame transmitted by the opposite device, and holds the reception status of the CCM frame (whether the CCM frame is received) (predetermined storage unit) To remember). When the OAM processing unit 9 does not receive a CCM frame for a predetermined time, the OAM processing unit 9 detects that a failure has occurred in communication with the opposite apparatus. Further, when failure information is included in the CCM frame transmitted by the opposite device, the OAM processing unit 9 holds the failure information (stores it in a predetermined storage unit). Further, the OAM processing unit 9 generates CCM frames at a predetermined time interval and sends them to the frame transfer unit 8 so as to transmit them to the opposite device. Further, when detecting the occurrence of a failure, the OAM processing unit 9 generates a CCM frame including failure information and transmits it to the opposite device.

[CCM frame]
FIG. 4 is a diagram schematically illustrating a configuration example of the CCM frame 12.

  The CCM frame 12 is a frame conforming to a communication standard such as ITU-T international recommendation “Y.1731” or IEEE802.1ag, and the OAM processing unit 7 of the switch 1 and the OAM processing unit 9 of the optical transmission apparatus 2a. Is generated. When the occurrence of a communication failure is detected, the OAM processing unit 7 of the switch 1 and the OAM processing unit 9 of the optical transmission device 2a store various types of failure information in the CCM frame 12. Hereinafter, the configuration of the CCM frame 12 will be described. Note that the basic configuration of the CCM frame 12 conforms to the communication standard described above, and a detailed description thereof will be omitted as appropriate.

  4 includes a DA (Destination Address) area 14, an SA (Source Address) area 16, an S-TAG (Service VLAN-TAG) area 18, a TYPE area 20, a data area 22, and an FCS (Frame Check). A (Sequence) area 24 is provided.

  The DA area 14 stores a multicast address. The SA area 16 stores the MAC (Media Access Control) address of the transmission source switch 1 or the optical transmission apparatus that generated the CCM frame 12. In the S-TAG area 18, for example, when VLAN (Virtual Local Area Network) is set, the VLAN information is stored. The TYPE area 20 stores information indicating that data related to OAM is stored in the data area 22.

  The data area 22 includes a header area 26, a seq area 28, an MEP ID area 30, an MEG ID area 32, an Rsv1731 area 34, an optional TLVs (Type Length Values) area 36, and an END area 38.

  FIG. 5 is a diagram showing a detailed configuration of the Optional TLVs area 36 included in the CCM frame 12. Since the basic configuration of the optional TLV area 36 conforms to the ITU-T international recommendation “Y.1731” and the IEEE 802.1ag communication standard, detailed description of each area is omitted here.

  The optional TLVs area 36 includes a TYPE area 40, a Length area 42, and a Value area 44. Further, an OUI (Organizationally Unique Identifier) 46 can be set in each area, and the OUI 46 is an identification number uniquely assigned to a vendor, for example.

  In the Value area 44, a fault information storage area for storing fault information is set. The Value area 44 includes an AIS (Alarm Indication Signal) area 44a, an RF (Remote Fault) area 44b, an LF (Local Fault) area 44c, a DG (Dying Gasp) area 44e, and a Reserved area 44d. In the present embodiment, the AIS area 44a, the RF area 44b, the LF area 44c, and the DG area 44e correspond to the failure information storage area. In the AIS area 44a, the RF area 44b, and the LF area 44c, for example, when communication is normally performed between the switch 1 and the optical transmission device 2a illustrated in FIG. 1, the values are set to OFF (0). Yes. On the other hand, when it is detected that a failure has occurred in the communication executed between the above, the value of the area corresponding to this is set to ON (1) as failure information according to the state of the communication failure.

  Further, the DG area 44e is set to ON (1) as failure information indicating that a power interruption has occurred when a power interruption has occurred in the switch 1 or the optical transmission apparatus. When the switch 1 or the optical transmission apparatus detects a power interruption, the switch 1 or the optical transmission apparatus generates a CCM frame storing (1) in the DG area 44e and transmits it to the opposite apparatus.

[Operation of network system]
FIG. 6 is a diagram illustrating an operation of transmitting a CCM frame in the network system according to the present embodiment.

  In FIG. 6, an Ethernet OAM maintenance domain is set between the switch 1 and the optical transmission device 2a. The switch 1 and the optical transmission device 2a are set as a management end point (MEP) in this maintenance domain. Based on this setting, the switch 1 and the optical transmission device 2a transmit a CCM frame (CCM in FIG. 6) to the other party. The switch 1 and the optical transmission device 2a confirm the reception of the CCM frame and hold the reception status of the CCM frame. The same applies to between the switch 1 and the optical transmission device 2b and between the switch 1 and the optical transmission device 2c.

  FIG. 7 is a diagram illustrating an operation in which the optical transmission apparatus notifies the switch of the occurrence of power interruption in the network system according to the present embodiment.

  In FIG. 7, the optical transmission apparatus 2a has a power interruption due to, for example, a failure. When the optical transmission device 2a detects the occurrence of the power interruption, the optical transmission device 2a generates a CCM frame (CCM (DG) in FIG. 7) in which (1) is stored in the DG area 44e and transmits it to the switch 1.

  When the switch 1 receives the CCM (DG), the switch 1 refers to the DG area 44e, and knows that the optical transmission apparatus 2a has been powered off based on the fact that (1) is stored. The switch 1 holds failure information that a power failure has occurred in the optical transmission device 2a.

  The network administrator states the optical transmission devices 2a, 2b, 2c on the user network side (the connection state between the switch 1 and the optical transmission devices 2a, 2b, 2c, the operational state of the optical transmission devices 2a, 2b, 2c, etc.) When confirming, the management terminal is connected to the switch 1. Since the switch 1 holds the reception status and failure information of the CCM frames from the optical transmission apparatuses 2a, 2b, and 2c, the network administrator reads the information held by the switch 1 using the management terminal. Thus, it is possible to grasp the connection state between the switch 1 and the optical transmission devices 2a, 2b, and 2c and the operation state of the optical transmission devices 2a, 2b, and 2c. For example, when a power failure has occurred in the optical transmission device 2a, the switch 1 holds the failure information that the power failure has occurred in the optical transmission device 2a by receiving the CCM (DG). By reading information from the switch 1, the administrator can grasp that the optical transmission device 2 a has been turned off.

  According to the network system of the present embodiment, the network administrator can read the state of the optical transmission devices 2a, 2b, and 2c from the switch 1, so that the optical transmission can be performed as compared with the prior art shown in FIG. The state of the devices 2a, 2b, and 2c can be easily grasped with little effort.

  Also, according to the network system of the present embodiment, since a failure information storage area for storing failure information indicating that a power failure has occurred is set in the CCM frame, a power failure has occurred using the CCM frame. This can be notified to the opposite device. Since an Ethernet OAM CCM frame is used and there is no need to separately generate a control frame for notifying that a power interruption has occurred, there is an advantage that mounting is easy.

  In this embodiment, the Ethernet OAM CCM frame is used as the connectivity confirmation information for confirming the connectivity between the switch and the optical transmission apparatus, but the present invention is not limited to this. It is also possible to use a control frame according to a proprietary standard as connectivity confirmation information.

  In this embodiment, the switch and the optical transmission apparatus transmit CCM frames to each other, but for the purpose of notifying the switch of failure information from the optical transmission apparatus, the optical transmission apparatus It is also possible to implement an embodiment in which connectivity confirmation information is transmitted to only the switch.

  In this embodiment, CCM frames that do not include failure information are transmitted at predetermined time intervals, and CCM frames that include failure information are transmitted when a failure occurs. As a modified example, for the purpose of notifying the switch of the occurrence of power failure of the optical transmission apparatus, the optical transmission apparatus does not transmit CCM frames that do not include failure information at predetermined time intervals. An embodiment is also feasible in which, when a power interruption occurs and is detected, connectivity confirmation information including failure information indicating the occurrence of the power interruption is generated and transmitted to the switch.

  While the embodiments of the present invention have been described above, the embodiments described above do not limit the invention according to the claims. In addition, it should be noted that not all the combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

DESCRIPTION OF SYMBOLS 1 Switch 1a, 1b, 1c, 1d Port 2a, 2b, 2c Optical transmission apparatus 2a1, 2b1, 2c1 Long-distance port 2a2, 2b2, 2c2 User port 3 Station 4 Wide area network 5a, 5b, 5c User network 6 Frame transfer control Units 7, 9 OAM processing unit 8 Frame transfer unit

Claims (6)

A switch comprising a plurality of ports and transferring frames between the plurality of ports;
A plurality of optical transmission devices comprising a user port and a long-distance port, and transferring frames between the user port and the long-distance port;
With
Each port of the plurality of ports of the switch is connected to the long distance port of each optical transmission device of the plurality of optical transmission devices,
When each of the optical transmission devices detects occurrence of a failure, the optical transmission device transmits connectivity confirmation information including failure information to the switch, and the switch holds the failure information.
Network system. The switch and each optical transmission device transmit the connectivity confirmation information to the other party,
The network system according to claim 1. A failure information storage area for storing failure information indicating that a power failure has occurred is set in the connectivity confirmation information,
Each of the optical transmission devices, when a power failure occurs, transmits the connectivity confirmation information storing failure information indicating that the power failure has occurred in the failure information storage area.
The network system according to claim 1 or 2. The switch and each optical transmission device transmit an Ethernet OAM CCM frame as the connectivity confirmation information.
The network system according to claim 2. A failure information storage area for storing failure information indicating that a power failure has occurred in the CCM frame is set.
Each optical transmission device transmits the CCM frame storing failure information indicating that the power failure has occurred in the failure information storage area when a power failure occurs.
The network system according to claim 4. The switch is disposed on a wide area network side, and the plurality of optical transmission devices are disposed on a user network side.
The network system according to claim 1.

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