JP4676538B2 - Communication apparatus and communication system - Google Patents

Description

The present invention relates to a communication apparatus and communication system, and more particularly, to a communication apparatus and communication system comprising a link aggregation and MPLS OAM functions.

Devices that provide a function called link aggregation (LAG) are known. LAG is a technology that uses a plurality of physical ports as a single logical port between two devices. A device that supports LAG selects an output physical port belonging to a LAG port from identification information (ID) that specifies a VLAN (Virtual LAN) tag and a flow such as MAC.
Some MPLS (Multi-Protocol Label Switching) communication apparatuses determine an MPLS LSP (Label Switching Path) connection from a VLAN, for example. An MPLS communication apparatus having a maintenance function by MPLS OAM (Operations, Administration and Maintenance) monitors connection end-to-end (EtoE) connectivity by periodically transferring a continuity confirmation (CV) frame. Each interface determines that a failure has occurred when no CV frame is received, and switches the connection from the 0 system to the 1 system.

ITU-T Recommendation Y. 1710 SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE AND INTERNET PROTOCOL ASPECTS, Internet protocol aspects-Operation, administration and maintenance Draft Recommendation Y.D. 1720 (Protection switching for MPLS networks) Meeting, data: Kobe (Japan), 22-27 April, 2006 “Ammentment to Carrier Sense Multiple Access with Collision Detection (CSMA / CD), Access Method and Physical Layer Emulsion 80,” “Essential Method and Physical Layer Emulsion 80”. 95-pp. 115, June 28, 2000

In an apparatus that connects an Ethernet (registered trademark, the same shall apply hereinafter) network and an MPLS network, path redundancy may be used in both networks. Although the Ethernet network and the MPLS network have different layers, the carrier side may use the MPLS network with an emphasis on reliability, and the user side may use a relatively inexpensive Ethernet network. Since the redundant configuration of the Ethernet network and the MPLS network is realized by different functions, conventionally, it has been difficult to provide a consistent redundant path.
Also, there is no known system that connects a device that supports LAG and an MPLS communication device having an MPLS OAM function. When these are connected, for example, the following points become problems.
LAG uses a plurality of physical ports as one logical port. The VLAN flow input from the LAG port to the MPLS communication apparatus needs to be transferred through the same MPLS LSP connection even if the physical port (line interface) is different. However, in the conventional MPLS communication apparatus, there is a case where flows input to different IFs cannot be transferred through the same MPLS LSP connection.

Further, when the number of OAM insertion points of the device A becomes two, two CV frames arrive at the OAM termination point of the opposite device B within a predetermined time from the same MPLS connection. In a normal OAM termination point, the normality of the connection is confirmed when one CV frame arrives within a predetermined time.
Further, since the switch unit of the device A distributes the frame transfer destination by the LSP ID (label), the traffic from the device B to the device A is biased to one of a plurality of physical ports corresponding to the LAG port. Therefore, a CV frame cannot be received by a physical port that cannot receive traffic. A physical port that has not received a CV frame may erroneously detect a failure.
In view of the above, it is an object of the present invention to provide a communication device and a communication system that can provide Ethernet section redundancy by link aggregation and MPLS section redundancy by a maintenance function by MPLS OAM. Another object of the present invention is to transfer frames received by a plurality of interfaces corresponding to link aggregation to the same path. An object of the present invention is to prevent erroneous detection of a failure of MPLS OAM. Furthermore, an object of the present invention is to prevent a user frame from being biased to one of a plurality of interfaces corresponding to link aggregation.

The same entry information is stored in, for example, a table for assigning labels of a plurality of physical ports to be LAG set. By so doing, multiplexing to the same LSP is possible even between different IFs.
One of the plurality of physical ports is defined as OAM ACT (act), and the other ports are defined as OAM SBY (standby). Only the OAM ACT port transmits the OAM frame. By doing so, it is possible to prevent reception of more than a specified number of CV frames in the opposing MPLS communication apparatus.
Only ports defined as OAM ACT receive OAM frames. Other ports are set to OAM SBY, and failure detection by CV reception is not performed. For example, for a frame received from the MPLS network with the switch forwarding table set to be a physical port with the forwarding destination set to OAM ACT, the OAM frame can be terminated at the OAM ACT port. By doing so, it is possible to prevent faulty detection due to OAM not being received.
Further, when the OAM ACT port is blocked due to an Ethernet link failure, the OAM SBY port is switched to ACT. Further, the transfer destination by the switch is changed to the OAM ACT port after switching. When there are a plurality of OAM SBY ports, priorities may be given.

According to the first solution of the present invention,
When multiple physical ports are bundled and used as one logical port and the output destination of the received frame is a link aggregation port that is the logical port, the frame is transferred to one of the physical ports of the link aggregation port Connected to the first communication device and connected to the second communication device via a communication network having a redundant configuration by the first path and the second path, and the frame input from the first communication device. Is encapsulated with a label, transferred to the second communication device, removed from the frame input from the second communication device, decapsulated, and transferred to the first communication device. And
A first interface for connecting to the first path;
A second interface for connecting to the second path;
A third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port;
A fourth interface unit for connecting to a second physical port of the first communication device constituting a link aggregation port;
Corresponding to the labels of the first path and the second path, the labels of the frames to which the labels are given have a transfer table in which the identifiers of the first to fourth interface units are stored as output destination information. A switch unit for referring to the forwarding table based on the above and forwarding the frame according to the corresponding output destination information,
The third interface unit includes a first storage unit in which whether the failure detection act system or the standby system is set, and the first storage unit is set to the act system;
The fourth interface unit has a second storage unit in which whether the failure detection act system or the standby system is set, and the second storage unit is set to the standby system,
The third interface unit receives a user frame transmitted from the first physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The fourth interface unit receives a user frame transmitted from the second physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The third interface unit transmits a continuity confirmation frame to the second communication device according to the first storage unit set to act system,
The fourth interface unit does not transmit a continuity confirmation frame to the second communication device according to the second storage unit set to a standby system,
The third forwarding table is set in the act system as output destination information corresponding to a downstream label received by the first and second interface units via the first and second paths. At least the identifier of the interface unit is stored, and the switch unit transmits the continuity confirmation frame received from the second communication device via the first path and the second path according to the transfer table. Forward to the interface part,
The third interface unit receives a continuity confirmation frame transmitted at a predetermined interval by the second communication device, and the continuity confirmation frame is received according to the first storage unit set to act system. Detecting a failure in the first or second path by not being received,
The fourth interface unit is provided with the communication device that does not detect a failure due to a continuity confirmation frame not being received in accordance with the second storage unit set to a standby system.

According to the second solution of the present invention,
When multiple physical ports are bundled and used as one logical port and the output destination of the received frame is a link aggregation port that is the logical port, the frame is transferred to one of the physical ports of the link aggregation port Connected to the first communication device and connected to the second communication device via a communication network having a redundant configuration by the first path and the second path, and the frame input from the first communication device. Is encapsulated with a label, transferred to the second communication device, removed from the frame input from the second communication device, decapsulated, and transferred to the first communication device. And
A first interface for connecting to the first path;
A second interface for connecting to the second path;
A third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port;
A fourth interface unit for connecting to a second physical port of the first communication device constituting a link aggregation port;
Corresponding to the labels of the first path and the second path, the labels of the frames to which the labels are given have a transfer table in which the identifiers of the first to fourth interface units are stored as output destination information. A switch unit for referring to the forwarding table based on the above and forwarding the frame according to the corresponding output destination information,
The third interface unit includes a first storage unit in which whether the failure detection act system or the standby system is set, and the first storage unit is set to the act system;
The fourth interface unit has a second storage unit in which whether the failure detection act system or the standby system is set, and the second storage unit is set to the standby system,
The third interface unit receives a user frame transmitted from the first physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The fourth interface unit receives a user frame transmitted from the second physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The third interface unit transmits a continuity confirmation frame to the second communication device according to the first storage unit set to act system,
The fourth interface unit does not transmit a continuity confirmation frame to the second communication device according to the second storage unit set to a standby system,
The forwarding table performs link aggregation as the first output destination information for the user frame corresponding to the downlink label received by the first and second interfaces via the first and second paths. And an identifier of the third interface unit set in the act system as second output destination information for the continuity confirmation frame is stored,
The switch part is
Identifying whether the frame received from the second communication device is a user frame or a continuity confirmation frame;
In the case of a user frame, one of the interface units belonging to the link aggregation indicated by the first output destination information in the forwarding table is selected based on a predetermined rule, and the first interface unit is selected via the selected interface unit. Forward the frame to one communication device,
In the case of a continuity confirmation frame, the frame is transferred to the third interface according to the second output destination information of the transfer table,
The third interface unit receives a continuity confirmation frame transmitted at a predetermined interval by the second communication device, and the continuity confirmation frame is received according to the first storage unit set to act system. Detecting a failure in the first or second path by not being received,
The fourth interface unit is provided with the communication device that does not detect a failure due to a continuity confirmation frame not being received in accordance with the second storage unit set to a standby system.

According to the third solution of the present invention,
When multiple physical ports are bundled and used as one logical port and the output destination of the received frame is a link aggregation port that is the logical port, the frame is transferred to one of the physical ports of the link aggregation port A first communication device that
A second communication device connected via a communication network having a redundant configuration by the first path and the second path;
A frame connected to the first communication device and the second communication device, encapsulating a frame input from the first communication device with a label, and transferring the frame to the second communication device. From the second communication device, A communication system comprising a third communication device for removing a label from an input frame, decapsulating and transferring to the first communication device;
The third communication device is:
A first interface for connecting to the first path;
A second interface for connecting to the second path;
A third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port;
A fourth interface unit for connecting to a second physical port of the first communication device constituting a link aggregation port;
Corresponding to the labels of the first path and the second path, the labels of the frames to which the labels are given have a transfer table in which the identifiers of the first to fourth interface units are stored as output destination information. A switch unit that refers to the forwarding table based on the
The third interface unit includes a first storage unit in which whether the failure detection act system or the standby system is set, and the first storage unit is set to the act system;
The fourth interface unit has a second storage unit in which whether the failure detection act system or the standby system is set, and the second storage unit is set to the standby system,
The third interface unit receives a user frame transmitted from the first physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The fourth interface unit receives a user frame transmitted from the second physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The third interface unit transmits a continuity confirmation frame to the second communication device according to the first storage unit set to act system,
The fourth interface unit does not transmit a continuity confirmation frame to the second communication device according to the second storage unit set to a standby system,
The third forwarding table is set in the act system as output destination information corresponding to a downstream label received by the first and second interface units via the first and second paths. At least the identifier of the interface unit is stored, and the switch unit transmits the continuity confirmation frame received from the second communication device via the first path and the second path according to the transfer table. Forward to the interface part,
The third interface unit receives a continuity confirmation frame transmitted at a predetermined interval by the second communication device, and the continuity confirmation frame is received according to the first storage unit set to act. Detecting a failure in the first or second path by not being received,
The fourth interface unit is provided with the communication system according to the second storage unit set as a standby system, and does not detect a failure due to a continuity confirmation frame not being received.
According to the fourth solution of the present invention,
When multiple physical ports are bundled and used as one logical port and the output destination of the received frame is a link aggregation port that is the logical port, the frame is transferred to one of the physical ports of the link aggregation port A first communication device that
A second communication device connected via a communication network having a redundant configuration by the first path and the second path;
A frame connected to the first communication device and the second communication device, encapsulating a frame input from the first communication device with a label, and transferring the frame to the second communication device. From the second communication device, A communication system comprising a third communication device for removing a label from an input frame, decapsulating and transferring to the first communication device;
The third communication device is:
A first interface for connecting to the first path;
A second interface for connecting to the second path;
A third interface unit for connecting to a first physical port of the first communication device constituting a link aggregation port;
A fourth interface unit for connecting to a second physical port of the first communication device constituting a link aggregation port;
Corresponding to the labels of the first path and the second path, the labels of the frames to which the labels are given have a transfer table in which the identifiers of the first to fourth interface units are stored as output destination information. A switch unit that refers to the forwarding table based on the
The third interface unit includes a first storage unit in which whether the failure detection act system or the standby system is set, and the first storage unit is set to the act system;
The fourth interface unit has a second storage unit in which whether the failure detection act system or the standby system is set, and the second storage unit is set to the standby system,
The third interface unit receives a user frame transmitted from the first physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The fourth interface unit receives a user frame transmitted from the second physical port of the first communication device, encapsulates the user frame with a label of a first path, and the switch unit first Transferring the user frame to the second communication device via the path of
The third interface unit transmits a continuity confirmation frame to the second communication device according to the first storage unit set to act system,
The fourth interface unit does not transmit a continuity confirmation frame to the second communication device according to the second storage unit set to a standby system,
The forwarding table performs link aggregation as the first output destination information for the user frame corresponding to the downlink label received by the first and second interfaces via the first and second paths. And an identifier of the third interface unit set in the act system as second output destination information for the continuity confirmation frame is stored,
The switch part is
Identifying whether the frame received from the second communication device is a user frame or a continuity confirmation frame;
In the case of a user frame, one of the interface units belonging to the link aggregation indicated by the first output destination information in the forwarding table is selected based on a predetermined rule, and the first interface unit is selected via the selected interface unit. Forward the frame to one communication device,
In the case of a continuity confirmation frame, the frame is transferred to the third interface according to the second output destination information of the transfer table,
The third interface unit receives a continuity confirmation frame transmitted at a predetermined interval by the second communication device, and the continuity confirmation frame is received according to the first storage unit set to act system. Detecting a failure in the first or second path by not being received,
The fourth interface unit is provided with the communication system according to the second storage unit set as a standby system, and does not detect a failure due to a continuity confirmation frame not being received.

ADVANTAGE OF THE INVENTION According to this invention, the communication apparatus and communication system which can provide the redundancy of the Ethernet area by link aggregation and the redundancy of the MPLS area by the maintenance function by MPLS OAM can be provided. Further, according to the present invention, frames received by a plurality of interfaces corresponding to link aggregation can be transferred to the same LSP. According to the present invention, erroneous detection of a failure of MPLS OAM can be prevented. Furthermore, according to the present invention, the user frame can be prevented from being biased to one of a plurality of interfaces corresponding to link aggregation.

Explanatory drawing of LAG. FIG. 2 is an explanatory diagram of an MPLS network and an MPLS communication apparatus connected to an MPLS communication apparatus that supports MPLS OAM. Explanatory drawing of an MPLS network frame and the forwarding table 310. FIG. FIG. 2 is a configuration diagram (1) of a line IF of an MPLS communication apparatus. Frame format in line IF. FIG. 1A is a diagram illustrating a configuration example of each table. FIG. 2 is a diagram (2) illustrating a configuration example of each table. MPLS OAM format. Explanatory drawing (1) of switching of an active system / standby system when a failure occurs in the 0 system (active system). Explanatory drawing (2) of switching of active system / standby system when a failure occurs in system 0 (active system). The system switching sequence diagram by CV non-reception. The flowchart of IF control CPU110 of a CV non-reception detection node. The flowchart of IF control CPU110 of an APS request receiving node. Explanatory drawing of the subject in a communication apparatus provided with a LAG and MPLS OAM function. The lineblock diagram of the system in a 1st embodiment. 3 shows a configuration example of a transfer table 310 and a LAG information database. The lineblock diagram of line IF10. Explanatory drawing of switching operation | movement of ACT / SBY when the failure generate | occur | produces in an Ethernet area. Table configuration example after switching due to occurrence of failure in Ethernet section. Flow chart (1) of switching due to the occurrence of a failure in the Ethernet section. Flow chart (2) for switching due to the occurrence of a failure in the Ethernet section. Illustration of working / protection switching when a failure occurs in the MPLS section. Flowchart of working / protection switching when a failure occurs in the MPLS section. The system block diagram in 2nd Embodiment. The block diagram of the transfer table 320 in 2nd Embodiment.

1. First embodiment (link aggregation)
FIG. 1 is an explanatory diagram of LAG. First, LAG will be described.
A general L2 switch (NW device) corresponding to the tag VLAN sets the relationship between the VLAN tag and the output port in the transfer table. The L2 switch learns the source MAC address, VLAN ID, and input physical port of the input frame. When a frame having the learned MAC address, VLAN ID as the destination is received, it searches the output port from the learning table. , Switching frames.
One of the functions of the L2 switch is a function called link aggregation (LAG) in which a plurality of physical ports are bundled and used as one logical port. Here, logical ports bundled by LAG are called LAG ports. LAG can provide, for example, the effect of logically increasing the line bandwidth and the effect of increasing redundancy. Note that, in the present embodiment, attention is paid to the direction of increasing redundancy, for example. The LAG port is a logical port composed of a plurality of physical ports (for example, physical ports 1 to 3 in FIG. 1A), but is recognized as one port by the switch.
When LAG is set, for example, a VLAN tag and its output port attribute are set in the forwarding table in the switch. When the destination of the received frame is destined for the LAG port, the switch transfers the frame to any physical port of the LAG port. As long as the physical port is LAG, no matter what port the frame is sent out, there is no problem in the LAG specification. In general, when a frame destination is a LAG port, the switch uses Hash to determine an output port. At this time, the Hash block performs Hash calculation using, for example, the destination MAC address and the VLAN ID, and specifies the transmission destination physical port of the frame. The calculation result of Hash is unique, and frames with the same VLAN ID and destination MAC are transferred to the same physical port. By using Hash, the frame can be effectively distributed among the LAG ports.

(MPLS)
Next, MPLS will be described according to the configuration of the present embodiment.
FIG. 2 is an explanatory diagram of an MPLS network and an MPLS communication apparatus to which an MPLS communication apparatus that supports MPLS OAM is connected. FIG. 3 is an explanatory diagram of an MPLS network frame and a forwarding table.
MPLS is a protocol characterized by encapsulating and transferring an input L2 frame or L3 frame with an MPLS label. For example, as shown in FIG. 3, an MPLS label and a new L2 header are added to the input original L2 frame and transferred. Here, the description will be given with the MPLS encapsulating the L2 frame, but this function is the same in the MPLS encapsulating the L3 frame. Also, in many MPLSs that encapsulate L2 frames, in general, there are many that encapsulate a frame with two MPLS labels, but here, for simplicity of explanation, the number of labels to be given is assumed to be one. Note that this function is the same in the method of encapsulating with a plurality of labels. The MPLS communication apparatus determines a frame transfer destination based on the LSP ID in the MPLS label.
The MPLS communication apparatus 1 includes, for example, a line IF # 1 (third interface unit) 11, a line IF # 2 (fourth interface unit) 12, an Uplink IF # 1 (third interface unit) 21, An Uplink IF # 2 (second interface unit) 22, a switch (SW) 30, and an overall control CPU (control unit) 40 are provided. The overall control CPU 40 is connected to each unit by, for example, a bus. A memory may be provided as appropriate. The switch 30 has a transfer table 310. For example, as shown in FIG. 3B, the transfer table 310 stores output port information corresponding to the LSP ID. Details of each part will be described later.
FIG. 4 is a configuration diagram (1) of the line IF of the MPLS communication apparatus. Each of the line IFs 11 and 12 can have the same configuration.

The line IF 10 includes a frame reception circuit 101, a label ID search block 102, a scheduler 112, a label assignment block 103, a switch transmission circuit 104, a switch reception circuit 105, an MPLS label processing unit 106, and a frame transmission circuit 107. An OAM termination unit 108, an OAM insertion unit 109, an IF control CPU 110, and a CPU interface 111. In addition, the line IF 10 includes an Ingress label search ID table (first label search table) 150, an active system table 160, an MPLS label table 170, an Egress label search ID table (second label search table) 180, And an MPLS label table 190.
6 and 7 are diagrams illustrating a configuration example of each table.
The Ingress label search ID table 150 is a table that holds label search IDs for searching the active system table 160 and the MPLS label table 170 corresponding to the VLAN ID. The search key of this table is the VLAN ID of the received frame. The acquired label search ID is held in the in-device header.
The operational system table 160 is a table that stores operational system information indicating a system in operation corresponding to the label search ID. For the active system, for example, identification information indicating the 0 system or the 1 system is held. The search key of this table is a label search ID.
The MPLS label table 170 is a table that holds an MPLS label ID (LSP ID, label) to be assigned when encapsulating a frame in correspondence with the operational system information and the label search ID. The search key of this table is operational system information and label search ID.
The Egress label search ID table 180 is a table that holds a label search ID and operation system information for searching the MPLS label table 190 corresponding to the MPLS label ID. The search key of this table is an MPLS label ID. In MPLS, different label IDs are used for uplink and downlink. Here, the label search ID for searching for the upstream label and the label search ID acquired from the downstream label are the same.

The MPLS label table 190 is a table that holds continuity confirmation information corresponding to the operational system information and the label search ID. The search key of this table is operational system information and label search ID. When the CV frame is received by the OAM termination unit 108, for example, an initial value “3” is written in the continuity confirmation information in this table, and “1” is subtracted once per second by the OAM insertion unit 109, for example. When this value becomes “0”, the CV is not reached for 3 seconds or more. When this value reaches a threshold value (for example, 0), that is, a connection failure is detected when CV has not reached for 3 seconds or more. Note that the initial value, the number to be subtracted, and the threshold for failure detection may be appropriate values. Alternatively, the connection failure may be detected when the initial value is added and a predetermined value is reached.
Valid indicates validity / invalidity of the entry. For example, when Valid is 1, the entry is valid, while when it is 0, the entry is invalid.
FIG. 5 shows a frame format in the line IF. In the in-device frame, an in-device header is added to the original L2 frame. The in-device header includes operational system information and a label search ID, for example.
FIG. 8 is an MPLS OAM format.
The MPLS OAM frame has, for example, an L2 header, an MPLS label, an MPLS OAM label, an OAM type, and an OAM payload. The MPLS label includes an LSP ID. In the MPLS OAM label, for example, an ID indicating 14 in decimal is stored. In the OAM type, information corresponding to CV and APS (system switching) is stored. The OAM payload stores information indicating whether the APS is an APS request or an APS response.
Returning to FIG. 4, each block will be described.
The frame receiving circuit 101 receives an L2 frame from a physical port (for example, physical port # 1), and adds an in-device header to the original L2 frame (for example, see FIG. 5). Here, the in-device header may be empty. The label ID search block 102 extracts the VLAN ID from the L2 header of the received frame, searches the Ingress label search ID table 150, and acquires the corresponding label search ID. Further, the label ID search block 102 stores the acquired label search ID in the in-device header of the received frame, and outputs the frame to the scheduler 112. For example, the scheduler 112 performs frame transmission scheduling. Also, a frame identification signal is output to the label assignment block 103 depending on whether the frame type is an OAM frame or a user frame.
The labeling block 103 has different processing operations for the OAM frame and the user frame. For example, when the frame identification signal from the scheduler 112 is “0”, it means a user frame. When receiving a user frame, the label assignment block 103 extracts the label search ID from the in-device header of the received frame, and acquires the operation system information corresponding to the label search ID from the operation system table 160. Also, the label assignment block 103 searches the MPLS label table 170 based on the acquired operational system information and the label search ID, and acquires the corresponding MPLS label ID. The label assigning block 103 generates an MPLS label from the MPLS label ID acquired from the table, generates an L2 header from new L2 header information registered in advance, and encapsulates the original L2 frame.

On the other hand, when the frame identification signal is “1”, for example, it means an OAM insertion frame (CV / APS). The label assignment block 103 searches the MPLS label table 170 using the operation system information and the label search ID acquired from the in-device header without searching the operation system table 160. The label assignment block 103 encapsulates the OAM frame with a new L2 header and an MPLS label. The switch transmission circuit 104 deletes the in-device header and transmits the encapsulated frame to the SW.
The switch receiving circuit 105 receives a frame from the SW. The MPLS label processing unit 106 confirms the MPLS label in the frame received from the SW side, and transfers the frame having the MPLS OAM label to the OAM termination unit 108. For other frames, the new L2 header and MPLS label are deleted and transferred to the frame transmission circuit 107. The frame transmission circuit 107 transmits the frame to a physical port (for example, physical port # 1).
The OAM insertion unit 109 searches all entries in the MPLS label table 190 once per second, for example. The OAM insertion unit 109 generates a payload of a CV frame for a registered entry or an entry whose Valid is valid “1”, and adds an in-device header including operational information obtained from the table and a label search ID. Are output (inserted) to the scheduler 112. The format of a frame inserted from the OAM insertion unit 109 is an in-device header, an MPLS OAM label, and an OAM payload (including OAM Type). Further, for example, 1 is subtracted from the value of the conduction confirmation information of the searched entry. If the value of the continuity confirmation information is already “0”, no subtraction is performed, and the operational control information of the entry whose continuity confirmation information value is “0”, the label search ID, and CV not received are indicated to the IF control CPU 110. Notify information.
Further, the OAM insertion unit 109 inserts an APS request frame and an APS response frame in accordance with the instruction.

The OAM termination unit 108 receives a frame having an MPLS OAM label from the MPLS label processing unit 106. The OAM termination unit 108 performs different operations when receiving the OAM frame CV, the APS request, and the APS response. The CV, APS request, and APS response can be identified by, for example, the OAM Type type value of the received frame or information indicating the request / response in the OAM payload.
When the CV is received, the OAM termination unit 108 searches the Egress label search ID table 180 using the MPLS label ID as a search key, and acquires the corresponding operational system information and the label search ID. The OAM termination unit 108 searches the MPLS label table 190 from the operational system information acquired from the Egress label search ID table 180 and the label search ID, and sets the corresponding conduction confirmation information to “3”, for example.
When receiving the APS request, the OAM termination unit 108 searches the Egress label search ID table 180 using the MPLS label ID as a search key, and acquires the corresponding operational system information and the label search ID. The OAM termination unit 108 notifies the IF control CPU 110 of the APS request reception notification including the operational system information acquired from the Egress label search ID table 180, the label search ID, and information indicating reception of the APS request.

When the APS response is received, the OAM termination unit 108 acquires the active system information and the label search ID from the Egress label search ID table 180 in the same manner as when the APS request is received. The IF control CPU 110 is notified of an APS response reception notification including information indicating reception of the APS response.
The IF control CPU 110 performs entry setting of each table, APS request / response frame insertion system switching processing, and the like. The CPU interface 111 is an interface between the IF control CPU 110 and the overall control CPU 40.
In the APS request insertion process, the IF control CPU 110 inputs the label search ID and the operational system information of the entry of the continuity confirmation information “0” from the OAM insertion unit 109. The IF control CPU 110 generates an APS request payload and an OAM label. Also, an in-device header is generated. In the apparatus header, the acquired label search ID and the operating system information of the system that transmits the APS request are stored. The operational system information of the system that transmits the APS request can be one of a system reverse to the operational system notified from the OAM insertion unit 109 or a system other than the operational system. That is, the APS request is transmitted using a system different from the system in which the failure has occurred.
In the APS response insertion process, the IF control CPU 110 inputs the above-described APS request reception notification from the OAM termination unit 108. The notification includes operational information and a label search ID. The IF control CPU 110 generates an APS response payload and an OAM label. Also, an in-device header is generated. The acquired label search ID and operational system information are stored in the in-device header. The IF control CPU 110 adds an OAM label and an in-device header to the payload, creates an APS response, and outputs it to the scheduler 112. The APS response is transferred in the same operational system as the APS request.
In the system switching process, the IF control CPU 110 receives the above-described APS response reception notification from the OAM termination unit 108. The notification includes a label search ID and operational information. The IF control CPU 110 searches the active system table 160 using the acquired label search ID, and rewrites the operating system information column of the table with the acquired operating system information.

(Switching between active and standby systems when a failure occurs-1)
9 and 10 are explanatory diagrams of switching between the active system and the standby system when a failure occurs in the 0 system (active system).
For example, when a failure occurs in the downstream of the 0 system (active system), the continuity confirmation frame is not received on the line IF of the MPLS communication apparatus 1. Thereby, for example, the conduction confirmation information in the MPLS label table 190 becomes 0 (for example, see FIG. 10B). When the CV is not received, the end node (for example, the line IF # 1 (11) of the MPLS communication apparatus 1) detects that a failure has occurred in the route, and sends a system switchover (APS) request frame to the upstream standby system connection. (LSP1000) is used for transmission. The start node (for example, the line IF # 1 (11) of the MPLS communication device 2) that has received the APS request frame transmits an APS response frame using the downlink standby system connection (LSP5000). The end node that has received the APS response frame rewrites the operating system information in the operating system table 160 in order to switch the system from the 0 system to the 1 system (FIG. 10 (a)).
As described above, in the MPLS communication apparatuses 1 and 2 that provide system switching using MPLS OAM, system switching is performed using CV non-reception as one of the triggers.

FIG. 11 is a system switching sequence diagram when CV is not received. In the figure, the IF control CPU 110 is included in the line IF as described above. However, for convenience of explanation, the IF control CPU 110 and other units are separated, and the parts other than the IF control CPU 110 are collectively referred to as a line IF.
The line IF # 1 (11) of the MPLS communication apparatus 2 transmits a CV frame to the line IF # 1 (11) of the MPLS communication apparatus 1 through, for example, a 0-system path periodically. Here, as an example, the first CV frame has reached the line IF # 1 (11) of the MPLS communication apparatus 1, but a failure has occurred in the 0-system path, and the subsequent CV frame is the line IF of the MPLS communication apparatus 1. Assume that # 1 (11) has not been received.
The line IF # 1 (11) (for example, the OAM termination unit 108) of the MPLS communication apparatus 1 cannot receive the CV frame for a predetermined time. The IF control CPU 110 is notified that CV has not been received. The IF control CPU 110 of the MPLS communication apparatus 1 instructs the line IF # 1 (11) (for example, the OAM insertion unit 109) of the MPLS communication apparatus 1 to insert an APS request. The line IF # 1 (11) (for example, the OAM insertion unit 109) of the MPLS communication apparatus 1 transmits an APS request frame to the line IF # 1 (11) of the MPLS communication apparatus 2 via the first system.

The line IF # 1 (11) (for example, the OAM termination unit 108) of the MPLS communication apparatus 2 receives the APS request frame and notifies the IF control CPU 110 of the MPLS communication apparatus 2 that the APS request is received. The IF control CPU 110 of the MPLS communication apparatus 2 instructs the line IF # 1 (11) (for example, the OAM insertion unit 109) of the MPLS communication apparatus 2 to insert an APS response. The line IF # 1 (11) of the MPLS communication apparatus 2 transmits an APS response frame to the line IF # 1 (11) (for example, the OAM insertion unit 109) of the MPLS communication apparatus 1 via the 1 system in accordance with the instruction. Further, the IF control CPU 110 of the MPLS communication apparatus 2 rewrites the operational system information in the operational system table 160 from the 0 system to the 1 system.
The line IF # 1 (11) (for example, the OAM termination unit 108) of the MPLS communication apparatus 1 receives the APS response frame, and notifies the IF control CPU 110 of the MPLS communication apparatus 1 that the APS response is received. The IF control CPU 110 of the MPLS communication apparatus 1 rewrites the operational system information in the operational system table 160 from the 0 system to the 1 system.
FIG. 12 is a flowchart of the IF control CPU 110 of the CV non-reception detection node. For example, it is a flowchart of the IF control CPU 110 of the MPLS communication apparatus 1 in FIG.

The IF control CPU 110 determines whether CV non-reception has been detected in the active system (S101). For example, the IF control CPU 110 refers to the operational system table 160 based on the label search ID included in the notification from the OAM insertion unit 109 and acquires whether the operational system is the 0 system or the 1 system. If the acquired active system and the active system information included in the notification from the OAM insertion unit 109 match, it is determined to be the active system, and if they do not match, it is determined not to be the active system. If it is determined that it is not an active system (S101, No), the process proceeds to step S109.
On the other hand, if it is determined that the system is the active system, the IF control CPU 110 instructs the standby system to insert an APS request frame (S103). The IF control CPU 110 monitors whether an APS response frame is received from the standby system (S105). For example, the monitoring of the reception of the APS response frame is continued until a timeout occurs (S105, No).
When receiving the APS response frame by the OAM termination unit 108 (S105, Yes), the IF control CPU 110 changes the operational system information in the operational system table 160 corresponding to the LSP that has received the APS response (S107). For example, the operational system information is rewritten from the 0 system to the 1 system. For example, when the APS response frame is received by the LSP 5000, the label search ID and the APS response receiving operational system that received the APS response are notified from the OAM termination unit 108 to the IF control CPU 110. The OAM termination unit 108 may acquire the label search ID and the operational system information by referring to the Egress label search ID table 180 based on the MPLS label ID. The IF control CPU 110 searches the active system table 160 using the label search ID, and changes the “active system” of the corresponding entry to the system that received the APS response. The table change location when receiving the APS response can be, for example, only one location. More specifically, first, the operational system (for example, system 1) and the label search ID (for example, 1) that received the APS are notified from the OAM termination unit 108 to the IF control CPU 110. Next, the IF control CPU 110 changes the operating system of the search ID “1” in the operating system table 160 illustrated in FIG. 6B from “0” to “1”.

The IF control CPU 110 notifies the overall control CPU 40 of the operation system switching (S109). For example, system information after switching (for example, system 1) is included.
FIG. 13 is a flowchart of the IF control CPU 110 of the APS request receiving node. For example, it is the flowchart of IF control CPU110 of the MPLS communication apparatus 2 in FIG.
When receiving the APS request, the IF control CPU 110 inserts an APS response frame into the opposite LSP of the LSP that has received the APS request frame (S201). For example, in FIG. 9, when an APS request frame is received from the LSP 1000, an APS response frame is inserted into the LSP 5000.
The IF control CPU 110 changes the operational system information in the operational system table 160 corresponding to the LSP that has received the APS request (S203). The operation and change location when receiving the APS request are the same as when receiving the APS response. 6 and 10 are examples of the table of the MPLS communication apparatus 1, but the MPLS communication apparatus 2 may have the same table configuration. For example, the active system table is searched from the label search ID that received the APS request, and the “active system” of the corresponding entry is changed to the active system that received the APS. The same applies when the MPLS communication device 1 receives an APS request from the MPLS communication device 2.
Further, the IF control CPU 110 notifies the overall control CPU 40 of the operation system switching (S205). For example, system information after switching (for example, system 1) is included.

(LAG and MPLS OAM)
FIG. 14 is an explanatory diagram of a problem in a communication apparatus having the LAG and MPLS OAM functions.
LAG is a technique for bundling a plurality of physical ports and operating them as one logical port. Therefore, VLAN flows belonging to the same MPLS connection need to be transferred through the same MPLS label path and the same path even if they are input from different physical ports. However, in the conventional MPLS communication apparatus, since the header processing table is individually held by the line IF, there is a case where the VLAN frame cannot be transmitted through the same uplink connection. As for the downstream frame, since the switch 30 switches the route with the LSP ID, the frame can be transferred only to one of the line IFs. Here, “up” refers to the direction from the Ethernet interval to the MPLS interval, and “down” refers to the direction from the MPLS interval to the Ethernet interval.
That is, in the conventional MPLS communication apparatus, for example, the following points are problems.
First, there are cases where upstream frames cannot be transferred by the same LSP. In some cases, only downstream frames can be transferred with a bias. Since the OAM frame can be transferred to only one physical port, there is a possibility that the OAM termination unit 108 of another physical port will not arrive at the OAM and erroneously detect a failure.
When a frame is transferred from a plurality of physical ports using the same LSP, the CV frame from each line IF is also transmitted using the same LSP. Therefore, in the opposing MPLS communication apparatus, the CV frame from the same LSP is transmitted for one second. There was a possibility of recognizing it because it received more than the specified number of CV frames, such as receiving two or more. Furthermore, there is a possibility that band expansion cannot be provided among the advantages of LAG due to the occurrence of a bias in the transfer destination line IF of the downstream user frame.

(System connecting link aggregation and MPLS)
FIG. 15 is a configuration diagram of a system in the present embodiment. FIG. 16 is a configuration example of the transfer table 310 and the LAG information database.
The MPLS communication apparatus 1 includes, for example, line IFs # 1, 2 (11, 12), Uplink IFs # 1, 2 (21, 22), a switch 30, an overall control CPU 40, and a LAG information database 50. . The overall control CPU 40 is connected to each unit by, for example, a bus. A memory may be provided as appropriate. The switch 30 has a transfer table 310. For example, as shown in FIG. 3B, the transfer table 310 stores output port information corresponding to the LSP ID.
The opposite NW device (first communication device) bundles a plurality of physical ports and uses them as a logical port, and when the output destination of the received frame is a link aggregation port that is the logical port, the frame Is transferred to one of the physical ports of the link aggregation port.
The MPLS communication apparatus 1 includes an MPLS communication apparatus 2 (second communication apparatus) via an MPLS network (communication network) having a redundant configuration with a 0-system LSP (first path) and a 1-system LSP (second path). Connected. The MPLS communication device 1 encapsulates the frame input from the opposite NW device 3 with a label and transfers it to the MPLS communication device 2. The MPLS communication device 1 removes the label from the frame input from the MPLS communication device 2 and decapsulates it to the opposite NW device 3. Forward.
The Uplink IF # 1 (21) is an interface for connecting to the 0-system LSP. The Uplink IF # 2 (22) is an interface for connecting to the 1-system LSP. The line IF # 1 (11) is an interface for connecting to the first physical port constituting the link aggregation port of the opposite NW device 3. The line IF # 2 (12) is an interface for connecting to the second physical port that constitutes the link aggregation port of the opposite NW device 3.

The switch 30 includes a transfer table 310 in which the identifier of the interface unit is stored as output destination information corresponding to the labels of the 0-system LSP and the 1-system LSP. The switch 30 refers to the transfer table 310 based on the label of the frame to which the label is attached, and transfers the frame according to the corresponding output destination information.
The line IF # 1 (11) has an OAM ACT / SBY switching register (first storage unit) indicating an act system or a standby system for detecting a failure, and the first storage unit is set to an act system. . The line IF # 2 (12) has an OAM ACT / SBY switching register (second storage unit) indicating an act system or a standby system for detecting a failure, and the second storage unit is set to the standby system. .
The line IF # 1 (11) receives the user frame transmitted from the first physical port of the opposite NW device 3, encapsulates the user frame with the label of the 0 system LSP, and passes through the 0 system LSP by the switch 30. The user frame is transferred to the MPLS communication apparatus 2. The line IF # 2 (12) receives the user frame transmitted from the second physical port of the opposite NW device 3, encapsulates the user frame with the label of the 0 system LSP, and passes through the 0 system LSP by the switch 30. The user frame is transferred to the MPLS communication apparatus 2.
The line IF # 1 (11) transmits a continuity confirmation frame to the MPLS communication apparatus 2 in accordance with the first storage unit set to act. On the other hand, the line IF # 2 (12) does not transmit the continuity confirmation frame to the MPLS communication apparatus 2 in accordance with the second storage unit set to the standby system.
The forwarding table 310 is set in the act system as output destination information corresponding to the downstream label received by the line IF # 1 (11) and the line IF # 2 (12) via the 0-system and 1-system LSP. At least the identifier of the line IF # 1 (11) is stored. The switch 30 transfers the continuity confirmation frame received from the MPLS communication apparatus 2 via the 0-system LSP and the 1-system LSP to the line IF # 1 (11) according to the transfer table 310.

The line IF # 1 (11) receives the continuity confirmation frame transmitted at a predetermined interval by the MPLS communication apparatus 2, and does not receive the continuity confirmation frame according to the first storage unit set to the act system. Thus, the failure of the first or first system LSP is detected. On the other hand, the line IF # 2 (12) does not detect a failure due to a continuity confirmation frame not being received in accordance with the second storage unit set to the standby system.
The MPLS communication apparatus 1 further includes a LAG information database. A configuration example of the LAG information database is shown in FIG. The LAG information database holds which physical port is configured for LAG. In the LAG information database, for example, LAG setting information indicating presence / absence of LAG setting corresponding to the physical port number, LAG port number (link aggregation identification information) to which the LAG setting belongs, and OAM ACT / SBY setting information And failure information indicating the presence / absence of a link failure of Ethernet (registered trademark, the same applies hereinafter). In addition to the port number, appropriate identification information can also be used. In this example, LAG setting information is set to “1” for a physical port for which LAG is set. The OAM ACT / SBY setting information is, for example, an ACT system when “1”, and an SBY system when “0”. The failure information indicates, for example, that there is a failure when “1” and there is no failure when “0”.
The physical port that becomes ACT in this database information is the output destination physical port of the transfer destination table. For example, the downstream output port of the transfer table 310 corresponds to a physical port set in the ACT system of the LAG information database. Here, since the ACT / SBY setting information corresponding to the physical port 1 is “1”, that is, the ACT system, the physical port 1 is included in the output port information corresponding to the downstream label (500, 5000) of the transfer table 310. It is remembered.

FIG. 17 is a configuration diagram of the line IF 10.
The line IF 10 includes a frame reception circuit 101, a label ID search block 102, a scheduler 112, a label assignment block 103, a switch transmission circuit 104, a switch reception circuit 105, an MPLS label processing unit 106, and a frame transmission circuit 107. An OAM termination unit 108, an OAM insertion unit 109, an IF control CPU 110, a CPU interface 111, and an OAM ACT / SBY switching register 200.
In the OAM ACT / SBY switching register 200, the own line IF is set to the ACT system or the SBY system. For example, it can be set for each physical port. The OAM ACT / SBY switching register 200 can be provided in each line IF unit. Note that information indicating the line IF and ACT / SBY may be stored in association with the outside of the line IF.
In order to transfer uplink frames input from a plurality of physical ports corresponding to the LAG port using the same MPLS LSP, the Ingress label search ID table 150, the active system table 160, the MPLS label table 170, the Egress label search ID table 180, and the MPLS The same setting value of the label table 190 is set in advance between the line IFs that perform LAG. These settings can be executed by the overall control CPU 40, for example. With this setting, frames received from the LAG port can be transferred by the same MPLS LSP even if the line IF is different.
In response to the non-reception of the continuity confirmation frame due to the deviation of the downstream frame due to the nature of the switch 30, the line IF (for example, the line IF # 1 (11)) set as the downstream output port by the switch 30 is OAM. As ACT, OAM insertion and termination processing (conductivity confirmation processing) are performed. On the other hand, a line IF (for example, line IF # 2 (12)) that is not set as a downlink output port by the switch 30 is set as OAM SBY, and the OAM insertion process and the termination process are not performed. In order to perform such processing, the line IF further includes an OAM ACT / SBY flag in the LAG information database. This flag may be provided for each line.

Furthermore, it is possible to have a line IF set to a plurality of SBY systems and perform priority link aggregation between the plurality of IFs. For example, it further includes a line IF # 3 (fifth interface unit) set to the SBY system. In this case, although not shown in the drawing, an SBY priority of the interface is set, and when a failure occurs in the physical port of the ACT, a variation such as using an SBY having a high priority as the ACT is also conceivable. The priority can be stored in advance in an appropriate database such as a LAG information database or in a memory corresponding to the physical port.
The line IF set to OAM SBY does not perform OAM insertion processing and OAM termination processing. Therefore, no fault is erroneously detected even if the OAM conduction frame is not received. With such a setting, LAG and MPLS OAM can be provided simultaneously.

(Failure in Ethernet section, ACT / SBY switching)
FIG. 18 is an explanatory diagram of the ACT / SBY switching operation when a failure occurs in the Ethernet section. For example, a case where a failure has occurred in a port for which LAG is set or a link corresponding to the port will be described.
If a failure occurs in a physical port (in this example, physical port 1) that is set to LAG and has OAM ACT, set the ACT / SBY flag in the LAG information database to the port where the failure occurred. SBY, a port in which no failure has occurred is set as ACT. Further, the OAM ACT / SBY switching register 200 of each line IF is switched, and a port where a failure has occurred is set as SBY, and a port where no failure has occurred is set as ACT.
Further, the setting of the transfer table 310 of the switch 30 is rewritten to a physical port in which no failure has occurred. By doing so, the operation can be continued without causing the influence of the failure in the Ethernet section to propagate to the transfer connection in the MPLS section.
FIG. 19 shows a table configuration example after switching due to the occurrence of a failure in the Ethernet section. 20 and 21 are flowcharts of switching due to the occurrence of a failure in the Ethernet section. Hereinafter, a specific example of switching processing due to the occurrence of a failure in the Ethernet section will be described. Note that the transfer table 310 before failure and the LAG information database are described as being set as shown in FIG. 16, for example.

FIG. 21A is a processing flowchart of the IF control CPU 110 in which the line IF has detected a failure.
When a failure occurs in the link in the Ethernet section, the IF control CPU 110 of the line IF detects a link loss from the physical port (S400). In this example, for example, the IF control CPU 110 of the line IF # 1 (11) detects the occurrence of a failure and executes the following processing.
The IF control CPU 110 sets the OAM ACT / SBY register of the own line IF to SBY (S401). The IF control CPU 110 notifies the overall control CPU 40 of the line IF link loss (S403). The notification can include a physical port number (in this example, physical port 1) corresponding to the own line IF.
FIG. 20 is a process flowchart of the overall control CPU 40 when a line IF failure is detected.
Upon receiving the link loss notification from the line IF (S300), the overall control CPU 40 executes the following processing. First, the overall control CPU 40 refers to the LAG information database (S301). For example, the entry of the physical port number corresponding to the line IF that received the link loss is searched. In this example, the entry of the physical port 1 is applicable. Further, the failure information of the corresponding entry is set to 1, for example.
The overall control CPU 40 determines whether the link loss detection physical port is a LAG port (S303). For example, referring to the LAG port information of the entry searched in step S301, if it is “1”, it is determined as a LAG port, and if it is “0”, it is determined not to be a LAG port. If it is determined that the port is not a LAG port (S303, No), the process is terminated.
On the other hand, if it is determined that the port is a LAG port (S303, Yes), the overall control CPU 40 determines whether the link loss detection physical port is an OAM ACT port (S305). For example, referring to the ACT / SBY setting information of the entry searched in step S301, if “1”, it is determined as an OAM ACT port, and if “0”, it is not an OAM ACT port (ie, OAM SBY port). to decide. If it is determined that the port is not an OAM ACT port (S305, No), the process is terminated.

On the other hand, when it is determined that the port is an OAM ACT port (S305, Yes), the overall control CPU 40 issues a change notification for setting the OAM ACT / SBY switching register 200 of any line IF belonging to the same LAG port to ACT. (S307). More specifically, the overall control CPU 40 searches the LAG information database for an entry having the same LAG port information as the LAG port information of the entry searched in step S301. In this example, the entry of the physical port 2 of the LAG port 1 is applicable. Further, the overall control CPU 40 notifies the IF control CPU 110 of the line IF corresponding to the physical port of the corresponding entry to set the OAM ACT / SBY switching register 200 to ACT. Further, the overall control CPU 40 sets the ACT / SBY setting information of the corresponding entry in the LAG information database to “1”, that is, ACT. Further, the overall control CPU 40 sets the ACT / SBY setting information of the entry searched in step S301 to “0”, that is, SBY.
Next, the overall control CPU 40 changes the transfer table 310 (S309). For example, the output port of the entry of the old OAM ACT port is changed to physical port information newly set in the OAM ACT. More specifically, the output port information corresponding to the downstream label (for example, 500, 5000) in the forwarding table 310 shown in FIG. 19A is rewritten to physical port information in which ACT of the LAG information database is set. Here, since the physical port 2 is set to the ACT system (FIG. 19B), the physical port 2 is rewritten.

FIG. 21B is a process flowchart of the IF control CPU 110 that has received the change notification of the OAM ACT / SBY switching register 200 from the overall control CPU 40.
When receiving the register change notification from the overall control CPU 40, the IF control CPU 110 of the line IF (in this example, the line IF # 2 (12)) sets the OAM ACT / SBY register of the own line IF to ACT (S451).
With the above processing, the line IF # 2 (12) becomes an ACT system, and communication in the down direction as well as in the up direction can be continued. Also, OAM insertion processing and termination processing are performed by the line IF # 2 (12) set in the ACT system, and the OAM function can be continued. Note that the opposing NW device 3 can also detect a link loss so that no frame is output to the link corresponding to the physical port 1 of the MPLS communication device 1.

(Failure in MPLS section, working / standby switching-2)
FIG. 22 is an explanatory diagram of working / standby switching when a failure occurs in the MPLS section.
Each of the line IF # 1 (11) and the line IF # 2 (12) manages an active system path (here, system 0) in the operating system table 160. For example, the line IF # 1 (11) set in the ACT system detects a failure in the active path when it cannot receive an OAM frame corresponding to the active path within a predetermined time. The line IF # 1 (11) changes the operation system information in the operation system table 160 of the own line IF to a backup path (here, system 1). For example, the active system path is switched from the 0 system to the 1 system by the system switching operation in steps S101 to S109 described above. Also, for example, other line IFs (for example, line IF # 2 (12)) are notified via the overall control CPU 40, and the other line IFs that have received the notification are operating system information in the operating system table 160 of the own line IF. To a backup path. By doing so, it is possible to continue the operation without spreading the influence of the failure in the MPLS section to the Ethernet section. After switching the active system, frames input from the physical ports 1 and 2 are also transferred using the 1-system LSP.

FIG. 23 is a flowchart of active / standby switching when a failure occurs in the MPLS section. FIG. 23A is a process flowchart of the overall control CPU 40 of the MPLS communication apparatus in which the active system switching has occurred.
First, the processing in steps S101 to S109 shown in FIG. 12 is executed. As a result, the operation system table 160 of the line IF (in this example, line IF # 1 (11)) in which a failure in the MPLS section is detected is updated to the first system as shown in FIG. 10A, for example. . In the following description, it is assumed that the LAG information database before the failure occurs is set as shown in FIG. Further, the operational system table 160 of the line IF # 2 (12) is set as shown in FIG.
When the overall control CPU 40 receives an operation system switching notification from the IF control CPU 110 of the line IF in which the failure is detected (S500), the overall control CPU 40 executes the following processing. Note that the active system switching notification includes the label search ID, the operating system information after switching (system 1 in this example), and the physical port number (physical port 1 in this example) corresponding to the line IF where the failure is detected. Can do.
The overall control CPU 40 refers to the LAG information database (S501). For example, the overall control CPU 40 searches for an entry of a physical port number included in the received active system switching notification.

The overall control CPU 40 determines whether the LSP that has switched the active system is a LAG port (S503). For example, the overall control CPU 40 refers to the LAG setting information of the retrieved entry, determines that it is a LAG port if it is “1”, and determines that it is not a LAG port if it is “0”. If it is determined that the port is not a LAG port (S503, No), the process is terminated.
On the other hand, if it is determined that the port is a LAG port (S503, Yes), the overall control CPU 40 and the label search ID obtained by switching the active system to the IF control CPU 110 of the physical port belonging to the same LAG port and set to SBY. The switched active system is notified (S505). More specifically, the overall control CPU 40 searches the LAG information database for an entry having the same LAG port information as the LAG port information of the entry searched in step S501. In the example of the LAG information database in FIG. 16B, the entry of the physical port 2 with LAG port information 1 corresponds. Also, the overall control CPU 40 provides the operational system including the label search ID and the operational system information after switching to the IF control CPU 110 of the line IF (for example, the line IF # 2 (12)) corresponding to the physical port of the corresponding entry. Send a switch notification. As the label search ID and the switched operational system information, the information included in the operational system switching notification received in step S500 can be used.

FIG. 23B is a process flowchart of the IF control CPU 110 that has received the active system switching notification from the overall control CPU 40.
For example, when the IF control CPU 110 of the line IF # 2 (12) receives the operation system switching from the overall control CPU 40, it searches the operation system table 160 with the specified label search ID and rewrites the operation system to the specified system ( S551). As a result, the operating system table 160 of the line IF # 2 (12) is also updated to the 1 system as shown in FIG. 10A, for example.
When the operating system table 160 is updated from the 0 system to the 1 system, the operating system refers to the entry of 1 when assigning an MPLS label ID to a frame input by referring to the MPLS label table 170 in the line IF. It will be. For example, in the case of a table as shown in FIG. 6C, when the label search ID is 1, if the operational system information is 0, the MPLS label ID is 100, and if the operational system information is 1, the MPLS label ID. Becomes 1000.

2. Second Embodiment FIG. 24 is a configuration diagram of a system according to a second embodiment.
In this embodiment, the setting of ACT / SBY of OAM is the same as that of the first embodiment. In the present embodiment, the SW 30 of the MPLS communication apparatus 1 further includes a Hash block 330. The forwarding table 320 holds user frame output port information and OAM ACT port information corresponding to the label. Other configurations are the same as those of the first embodiment.
In the first embodiment, the frame destined to the LAG port (downlink) is transferred to one of the line IFs. In this embodiment, the user frame is distributed to a plurality of line IFs. Note that the OAM frame is transferred to the line IF set in the ACT system, as in the first embodiment.

FIG. 25 is a configuration diagram of the transfer table 320 in the present embodiment.
The forwarding table 320 includes, for example, first output destination information for a user frame corresponding to a downlink label received by the Uplink IFs # 1, 2 (21, 22) via the first and second paths. As the identifier indicating the link aggregation, and the identifier of the line IF # 1 (11) set as the act system as the second output destination information for the continuity confirmation frame.
The switch 30 identifies whether the frame received from the MPLS communication device 2 is a user frame or a continuity confirmation frame. For example, refer to the OAM label of the frame. If an OAM label is added or if the OAM label is a predetermined value (for example, 14), it can be identified as an OAM frame such as a continuity confirmation frame, and the other can be identified as a user frame. In the case of a user frame, the switch 30 selects one of the interface units belonging to the link aggregation indicated by the first output destination information in the forwarding table 320 based on a predetermined rule. The switch 30 transfers the frame to the opposing NW device 3 via the selected interface unit. In the case of the continuity confirmation frame, the switch 30 transfers the frame to the line IF # 1 (11) according to the second output destination information in the transfer table 320.

For example, for the user frame destined for the LAG port, the SW 30 of the MPLS communication apparatus 1 extracts not only the MPLS label but also an ID for identifying a flow such as a MAC destination address (DA) or VLAN from the original frame, and a Hash block 330. The hash calculation is performed by the above, and the physical port is allocated according to the calculation result. As for the Hash calculation, an appropriate method can be used similarly to LAG. In addition to the hash calculation, the output destination of the downlink user frame may be selected from physical ports belonging to the LAG by an appropriate method. Note that which physical port belongs to the LAG can be stored in advance. Further, the above-described LAG information database may be referred to. In this way, it is possible to prevent the downlink data from being biased to one port, and it is also possible to provide an OAM function.
When a failure occurs in a physical port (for example, a port of line IF # 1 (11)) that is set to LAG and is in OAM ACT, as in the first embodiment described above, ACT / SBY The flag is set to SBY for a port in which a failure has occurred and ACT to a port in which no failure has occurred. In the first embodiment, the output port information in the SW transfer table 320 is rewritten to a physical port number in which no failure has occurred, but in this embodiment, the OAM ACT port information in the transfer table 320 is changed to a failure. Rewrite to the physical port number of the port where no error occurred. For example, the OAM ACT port information in the transfer table 320 shown in FIG.

  The present invention can be used, for example, in a system including a communication device having a link aggregation function and a communication device having an MPLS function.

1, 2, MPLS communication device 10, 11, 12 Line IF
21, 22 Uplink IF
30 switch 40 general control CPU
50 LAG information database 310 It has a forwarding table.
101 frame reception circuit 102 label ID search block 103 scheduler 103 label assignment block 104 switch transmission circuit 105 switch reception circuit 106 MPLS label processing unit 106
107 Frame Transmission Circuit 108 OAM Termination Unit 109 OAM Insertion Unit 109
110 IF control CPU
111 CPU interface 200 OAM ACT / SBY switching register 330 Hash block

Claims (22)

  A communication device connected to the first communication device and the second communication device via a communication network,
  A first interface for communicating via the second communication device and the first path,
  A second interface communicating with a second communication device via a second path forming a redundant configuration with the first path;
  A switch unit that forwards a frame to each interface according to the labels of the first path and the second path;
  A third interface that encapsulates a user frame received from a first physical port with the first communication device constituting a link aggregation port with a label corresponding to the first path, and forwards the frame to the switch unit; ,
  A fourth interface for encapsulating a user frame received from a second physical port with the first communication device constituting a link aggregation port with a label corresponding to the first path and transferring the frame to the switch unit; ,
  A storage unit for storing whether the third interface and the fourth interface are an act system or a standby system;
With
  The third interface and the fourth interface are respectively
  In the storage unit, when it is set to act system, the continuity confirmation frame received from the first communication device is transmitted to the second communication device,
  The communication device, wherein the storage unit does not transmit a continuity confirmation frame received from the first communication device to the second communication device when it is set to a standby system.   The communication device according to claim 1,
  The third interface and the fourth interface are:
  When the storage unit itself is set to act, the continuity confirmation frame transmitted from the second communication device at a predetermined interval is received, and the continuity confirmation frame is not received. Detect the failure of the first or second path,
  In the storage unit, when the device itself is set to a standby system, a failure detection due to the fact that the continuity confirmation frame is not received is not performed.   A control unit for controlling the third interface, the fourth interface and the switch unit,
  A transfer table in which identifiers of the first to fourth interfaces are stored as output destination information corresponding to the labels of the first path and the second path;
Further comprising
  The third interface of the act system is
  Upon detecting a failure of the link with the first communication device, the storage unit is set to be a standby system, and a switching notification is transmitted to the control unit,
  When the control unit receives the switching notification,
    Set in the storage unit that the fourth interface is an act system,
    The output destination information corresponding to the downstream labels of the first path and the second path in the forwarding table is changed from the identifier of the third interface to the identifier of the fourth interface. Communication equipment.   A transfer table in which identifiers of the first to fourth interfaces are stored as output destination information corresponding to the labels of the first path and the second path;
  A link aggregation information database storing link aggregation identification information for identifying a link aggregation port to which a link connected to the interface belongs, corresponding to the identifiers of the third and fourth interfaces;
  The third interface, and a control unit for controlling the fourth interface and the switch unit
Further comprising
  When the third interface detects a failure of a link with the first communication device, the third interface sets itself as a standby system to the first storage unit, and transmits a switching notification to the control unit,
  Wherein the control unit receives the said switching notification from the third interface,
    Referring to the link aggregation information database, the link aggregation identification information corresponding to the identifier of the third interface is obtained, and the identifier of the fourth interface having the same link aggregation identification information as the link aggregation identification information is obtained. ,
    Set in the storage unit that the acquired fourth interface is an act system, and
    By changing the output destination information corresponding to the downlink labels of the first path and the second path in the forwarding table to the acquired identifier of the fourth interface, the first path and the second path The communication device according to claim 1, wherein a continuity confirmation frame received from the second communication device via a path is transferred to the fourth interface according to the transfer table.   A fifth interface for connecting to a third physical port constituting a link aggregation port of the first communication device;
  Control unit for controlling the third to fifth interfaces and the switch unit
Further comprising
  In the storage unit, the fifth interface is set as a standby system,
  In the fourth interface and the fifth interface, the priority for changing to the act system is preset,
  When the third interface detects a failure of the link with the first communication device, the third interface sets the third interface as a standby system in the storage unit, and notifies the control unit of the switching. Send
  When the control unit receives the switching notification,
    According to the set priority, the storage unit sets that the fourth or fifth interface is an act system,
    By changing the output destination information corresponding to the downlink labels of the first path and the second path in the forwarding table to the identifier of the fourth or fifth interface according to the set priority, The continuity confirmation frame received from the second communication device via the first path and the second path is transferred to the fourth or fifth interface according to the transfer table. Communication equipment.   A control unit for controlling the third interface, the fourth interface, and the switch unit;
  Each of the third and fourth interfaces is
  Holds operational system information indicating the first pass of the operation system of the communication network,
  The third interface is
  When a failure of the first path is detected by not being able to receive a continuity confirmation frame transmitted at a predetermined interval from the second communication device, or when system switching information is received from the second communication device, Change the operational system information of its own interface to the second path, send a switch notification to the control unit,
  The controller is
  The communication apparatus according to claim 1, wherein when the switching notification is received, the operational information of the fourth interface is changed to a second path.   A link aggregation information database storing link aggregation identification information for identifying the link aggregation port to which the link connected to the interface belongs, corresponding to the identifiers of the third and fourth interfaces.
Further comprising
  When the control unit receives the switching notification from the third interface, the controller refers to the link aggregation information database to obtain link aggregation identification information corresponding to the identifier of the third interface, and the link aggregation identification information The communication apparatus according to claim 6, wherein an identifier of the fourth interface having the same link aggregation identification information is acquired, and the operational information of the fourth interface is changed to a second path according to the acquired identifier. .   The third and fourth interfaces are
  A first label search table storing a predetermined label search identifier corresponding to the virtual network identifier;
  Operational system information indicating an operational path corresponding to the label search identifier is stored, and an operational system table in which the operational system information is rewritten by detecting a path failure;
  A label table in which the labels of the first and second paths are stored in correspondence with the system information indicating the active system or the standby system and the label search identifier.
With
  The third and fourth interfaces are
  Upon receiving a user frame from the first communication device, a virtual network identifier is extracted from the user frame,
  Refer to the first label search table based on the extracted virtual network identifier to obtain a corresponding label search identifier;
  Based on the acquired label search identifier, refer to the operational table, identify operational information,
  Based on the operational system information and the acquired label search identifier, search the system information and the label search identifier in the label table to acquire the corresponding first or second path label,
  The communication apparatus according to claim 1, wherein the received user frame is encapsulated with the acquired label and transferred to the second communication apparatus.   The communication apparatus according to claim 8, wherein the first label search table, the active system table, and the label table store the same contents in the third interface and the fourth interface.   Corresponding to the labels of the first path and the second path, there is a transfer table in which identifiers of the first to fourth interfaces are stored as output destination information.
  The switch part is
  Identifying whether the frame received from the second communication device is a user frame or a continuity confirmation frame;
    In the case of a user frame, one of the interfaces belonging to the link aggregation indicated by the first output destination information in the forwarding table is selected based on a predetermined rule, and the first interface is selected via the selected interface. Forward the frame to the communication device,
    The communication apparatus according to claim 1, wherein in the case of a continuity confirmation frame, the frame is transferred to the third interface according to second output destination information of the transfer table.   When the identified frame is a user frame, the switch unit performs Hash calculation based on identification information for identifying a destination address and / or a flow of the frame input to the switch unit, and performs link aggregation based on the calculation result. The communication apparatus according to claim 10, wherein one of the interfaces belonging to is selected.   A first communication device;
  A second communication device;
  A third communication device connected to the first communication device and the second communication device via a communication network;
A communication system comprising:
  The third communication device is:
  A first interface communicating with a second communication device via a first path;
  A second interface communicating with a second communication device via a second path forming a redundant configuration with the first path;
  A switch unit that forwards a frame to each interface according to the labels of the first path and the second path;
  A third interface that encapsulates a user frame received from a first physical port with the first communication device constituting a link aggregation port with a label corresponding to the first path, and forwards the frame to the switch unit; ,
  A fourth interface for encapsulating a user frame received from a second physical port with the first communication device constituting a link aggregation port with a label corresponding to the first path and transferring the frame to the switch unit; ,
  A storage unit for storing whether the third interface and the fourth interface are an act system or a standby system;
With
  The third interface and the fourth interface are respectively
  In the storage unit, when it is set to act system, the continuity confirmation frame received from the first communication device is transmitted to the second communication device,
  The communication system, wherein the storage unit does not transmit a continuity confirmation frame received from the first communication device to the second communication device when the storage unit is set to a standby system.   A communication system according to claim 12,
  The third interface and the fourth interface are:
  When the storage unit itself is set to act, the continuity confirmation frame transmitted from the second communication device at a predetermined interval is received, and the continuity confirmation frame is not received. Detect the failure of the first or second path,
  The communication system according to claim 1, wherein when the storage unit is set as a standby system, a failure detection is not performed because the continuity confirmation frame is not received.   The third communication device is:
  A control unit for controlling the third interface, the fourth interface, and the switch unit;
  A transfer table in which identifiers of the first to fourth interfaces are stored as output destination information corresponding to the labels of the first path and the second path;
Further comprising
  The third interface of the act system is
  Upon detecting a failure of the link with the first communication device, the storage unit is set to be a standby system, and a switching notification is transmitted to the control unit,
  When the control unit receives the switching notification,
    Set in the storage unit that the fourth interface is an act system,
    The output destination information corresponding to the downstream labels of the first path and the second path in the forwarding table is changed from the identifier of the third interface to the identifier of the fourth interface. Communication system.   The third communication device is:
  A transfer table in which identifiers of the first to fourth interfaces are stored as output destination information corresponding to the labels of the first path and the second path;
  A link aggregation information database storing link aggregation identification information for identifying a link aggregation port to which a link connected to the interface belongs, corresponding to the identifiers of the third and fourth interfaces;
  The third interface, and a control unit for controlling the fourth interface and the switch unit
Further comprising
  When the third interface detects a failure of a link with the first communication device, the third interface sets itself as a standby system to the first storage unit, and transmits a switching notification to the control unit,
  Wherein the control unit receives the said switching notification from the third interface,
    Referring to the link aggregation information database, the link aggregation identification information corresponding to the identifier of the third interface is obtained, and the identifier of the fourth interface having the same link aggregation identification information as the link aggregation identification information is obtained. ,
    Set in the storage unit that the acquired fourth interface is an act system, and
    By changing the output destination information corresponding to the downlink labels of the first path and the second path in the forwarding table to the acquired identifier of the fourth interface, the first path and the second path The communication system according to claim 12, wherein a continuity confirmation frame received from the second communication device via a path is transferred to the fourth interface according to the transfer table.   The third communication device is:
  A fifth interface for connecting to a third physical port constituting a link aggregation port of the first communication device;
  Control unit for controlling the third to fifth interfaces and the switch unit
Further comprising
  In the storage unit, the fifth interface is set as a standby system,
  In the fourth interface and the fifth interface, the priority for changing to the act system is preset,
  When the third interface detects a failure of the link with the first communication device, the third interface sets the third interface as a standby system in the storage unit, and notifies the control unit of the switching. Send
  When the control unit receives the switching notification,
    According to the set priority, the storage unit sets that the fourth or fifth interface is an act system,
    By changing the output destination information corresponding to the downlink labels of the first path and the second path in the forwarding table to the identifier of the fourth or fifth interface according to the set priority, 13. The continuity confirmation frame received from the second communication device via the first path and the second path is transferred to the fourth or fifth interface according to the transfer table. Communication system.   The third communication device is:
  A control unit for controlling the third interface, the fourth interface, and the switch unit;
  Each of the third and fourth interfaces is
  Holds operational system information indicating the first pass of the operation system of the communication network,
  The third interface is
  When a failure of the first path is detected by not being able to receive a continuity confirmation frame transmitted at a predetermined interval from the second communication device, or when system switching information is received from the second communication device, Change the operational system information of its own interface to the second path, send a switch notification to the control unit,
  The controller is
  13. The communication system according to claim 12, wherein when the switching notification is received, the operational system information of the fourth interface is changed to the second path.   The third communication device is:
  A link aggregation information database storing link aggregation identification information for identifying the link aggregation port to which the link connected to the interface belongs, corresponding to the identifiers of the third and fourth interfaces.
Further comprising
  When the control unit receives the switching notification from the third interface, the control unit refers to the link aggregation information database to obtain link aggregation identification information corresponding to the identifier of the third interface, and the link aggregation identification information 18. The communication system according to claim 17, wherein an identifier of the fourth interface having the same link aggregation identification information is acquired, and operational information of the fourth interface is changed to a second path according to the acquired identifier. .   The third and fourth interfaces are
  A first label search table storing a predetermined label search identifier corresponding to the virtual network identifier;
  Operational system information indicating an operational path corresponding to the label search identifier is stored, and an operational system table in which the operational system information is rewritten by detecting a path failure;
  A label table in which the labels of the first and second paths are stored in correspondence with the system information indicating the active system or the standby system and the label search identifier.
With
  The third and fourth interfaces are
  Upon receiving a user frame from the first communication device, a virtual network identifier is extracted from the user frame,
  Refer to the first label search table based on the extracted virtual network identifier to obtain a corresponding label search identifier;
  Based on the acquired label search identifier, refer to the operational table, identify operational information,
  Based on the operational system information and the acquired label search identifier, search the system information and the label search identifier in the label table to acquire the corresponding first or second path label,
  The communication system according to claim 12, wherein the received user frame is encapsulated with the acquired label and transferred to the second communication device.   The communication system according to claim 19, wherein the first label search table, the active system table, and the label table store the same contents in the third interface and the fourth interface.   The third communication device is:
  Corresponding to the labels of the first path and the second path, there is a transfer table in which identifiers of the first to fourth interfaces are stored as output destination information.
  The switch part is
  Identifying whether the frame received from the second communication device is a user frame or a continuity confirmation frame;
    In the case of a user frame, one of the interfaces belonging to the link aggregation indicated by the first output destination information in the forwarding table is selected based on a predetermined rule, and the first interface is selected via the selected interface. Forward the frame to the communication device,
    13. The communication system according to claim 12, wherein in the case of a continuity confirmation frame, the frame is transferred to the third interface according to the second output destination information of the transfer table.   When the identified frame is a user frame, the switch unit performs Hash calculation based on identification information for identifying a destination address and / or flow of the frame input to the switch unit, and performs link aggregation based on the calculation result. The communication system according to claim 21, wherein one of the interfaces belonging to is selected.

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