JP7112353B2 - Communication device - Google Patents

Description

The present invention relates to a communication device that transmits and receives data.

The ring protocol is a technique of connecting communication devices that relay user frames in a ring shape and making communication paths redundant in Layer 2. FIG. Patent Document 1 is a typical ring protocol. A communication device that constitutes a network configured in a ring (ring network, hereinafter simply referred to as a “ring”) has a role of either a master device or a transit device.

In order to prevent a loop configuration in which communication loops within a route due to the characteristic of the ring configuration, the ring protocol defines a state in which user frames cannot be transferred in the network (hereinafter referred to as a blocking state) and a blocking state. is released and the ring is controlled in a state in which user frames can be transferred (hereinafter referred to as a forwarding state).

The master device controls the blocking state and the forwarding state for each VLAN (Virtual Local Area Network) used for communication of user frames. Such a VLAN is hereinafter referred to as a "data VLAN". The control frame transmits a VLAN (hereinafter referred to as a control VLAN) through which frames related to ring control communicate. The control VLAN is not subject to blocking or forwarding states.

The communication path of the ring is determined by the blocking state and forwarding state of the ring port of the master device. When the ring failure status is normal, the master device Ma puts one of its two ring ports into the blocking state and the other into the forwarding state. As a result, the master device Ma prevents the ring communication path from forming a loop. When the master device Ma detects a fault, it puts the ring port in the blocking state into the forwarding state to secure a communication path that avoids the faulty location.

A ring port that is in forwarding state when the fault condition of the ring is normal is called a primary port. A ring port that is in a blocking state when the ring fault condition is normal is called a secondary port.

Further, as an example of a ring traffic volume control method, there is a method of setting a transmission band for frames flowing within a ring (see, for example, Patent Document 2 below). The method of Patent Document 2 is a method of controlling the amount of traffic on the ring by setting a transmission band for each priority of frames flowing through the ring.

JP 2008-136013 A JP 2006-261825 A

However, when changing the route by switching the primary port and secondary port of the data VLAN for traffic volume control as described above, when the communication device constituting the ring receives a frame with an unlearned MAC address as the destination, , to all ports belonging to the received data VLAN (hereinafter referred to as flooding). Flooding increases traffic volume. Therefore, when a route is changed for traffic volume control, the traffic volume temporarily increases, increasing the probability of frame loss and delay.

An object of the present invention is to suppress the amount of traffic by preventing flooding when changing a blocking port.

A communication device, which is one aspect of the invention disclosed in the present application, is one of a group of communication devices constituting a ring network defined by a ring protocol, and a user frame is transmitted and received within the ring network. First transfer destination information capable of registering a combination of a MAC address and a port number for a first virtual network in which a MAC address and a port number are registered, and a combination of a MAC address and a port number can be registered for a second virtual network in which user frames are transmitted and received within the ring network. and second transfer destination information; and transfer destination information applied to the active virtual network when switching the active virtual network from the first virtual network to the second virtual network. and a control unit for switching from the first transfer destination information to the second transfer destination information.

According to the representative embodiment of the present invention, it is possible to suppress the amount of traffic by preventing flooding from occurring when switching communication paths.

FIG. 1 is an explanatory diagram of a configuration example of a network system according to a first embodiment; FIG. 2 is a block diagram of a module configuration example of the communication apparatus according to the first embodiment; FIG. 3 is an explanatory diagram showing an example of the FDB held by the communication device after MAC address learning is completed. FIG. 4 is an explanatory diagram of a format of a control frame according to the first embodiment; FIG. 5 is a device-to-device sequence diagram showing processing of the entire ring network when MAC address learning and MAC address clearing are performed at the external ring port of the master device. FIG. 6 is a device-to-device sequence diagram showing the processing of the entire ring network when MAC address learning and MAC address clearing are performed at an external ring port of a transit device. FIG. 7 is a sequence diagram between communication devices showing processing of the entire ring network when switching communication paths. FIG. 8 is a sequence diagram within the communication device during MAC address learning. FIG. 9 is a sequence diagram in the communication device when clearing the MAC address. FIG. 10 is a sequence diagram in the communication device when a control frame for adding a standby MAC address is received. FIG. 11 is a sequence diagram in the communication device when receiving the standby MAC address clear control frame. 12 is a sequence diagram in the master device at the time of communication path switching according to the first embodiment; FIG. FIG. 13 is a sequence diagram in the communication apparatus when receiving a control frame for a switching instruction according to the first embodiment; FIG. 14 is a sequence diagram in the communication device in user frame transfer pattern 1. FIG. FIG. 15 is a sequence diagram in the communication device in user frame transfer pattern 2. FIG. FIG. 16 is a sequence diagram in the communication device in user frame transfer pattern 3. FIG. FIG. 17 is a sequence within the communication device for switching processing of the active FDB. FIG. 18 is a block diagram of a module configuration example of the communication apparatus according to the second embodiment; FIG. 19 is an explanatory diagram of a format example of a control frame according to the second embodiment. FIG. 20 is a sequence diagram between communication devices showing processing of the entire ring network at the time of communication path switching according to the second embodiment. FIG. 21 is a sequence diagram in the master device at the time of communication path switching according to the second embodiment. FIG. 22 is a sequence within the communication apparatus when a control frame for switching instructions is received according to the second embodiment.

In the present embodiment, all communication devices constituting a ring network create in advance forwarding destination information (forwarding data base, hereinafter referred to as FDB) of frames after communication route switching, before switching, and forwarding information to the master device. The FDBs of all communication devices belonging to the ring are switched according to the instruction.

In order to realize this, two types of FDBs, an FDB used before communication path switching (hereinafter referred to as an active FDB) and an FDB used after communication path switching (hereinafter referred to as a standby FDB), are Each communication device has. The source MAC address of the received frame is registered in the active FDB. The MAC address notified by the control frame from another communication device is registered in the standby FDB. Therefore, a communication device belonging to a certain ring notifies a communication device belonging to another ring of the MAC address learned by the active FDB.

Switching of the communication path is executed by an instruction from the master device to the transit device among all the communication devices belonging to the ring. Upon receiving the instruction, the transit device switches the standby FDB to the active FDB and transfers the frame. Since the FDB has already been constructed before switching, flooding does not occur when the communication path is switched.

The network system according to the first embodiment uses two data VLANs (data VLAN1 and data VLAN2) in the ring network. Each communication device that configures the ring network has an FDB applied in the data VLAN1 and an FDB applied in the data VLAN2. When the active communication path switches from the data VLAN1 to the data VLAN2, the active FDB also switches from the FDB applied in the data VLAN1 to the FDB applied in the data VLAN2.

(1-1) Configuration of Network System FIG. 1 is an explanatory diagram illustrating a configuration example of a network system 100 according to the first embodiment. A master device Ma and a plurality of transit devices (in FIG. 1, two transit devices Mb and Mc as an example) are communication devices that relay user frames, and constitute a ring network.

The master device Ma has two ring ports pa1 and pa2 and a non-ring port (hereinafter referred to as an extra-ring port) pa3. The transit device Mb has two ring ports pb1, pb2 and an extra-ring port pb3. The transit device Mc has two ring ports pc1, pc2 and an extra-ring port pc3.

Master device Ma is connected to network Na by link Lan, which is a physical line. The network Na has, for example, a communication device Na1. Assume that the MAC address of the communication device Na1 is "aa-aa-aa-00-00-11".

A transit device Mb is connected to a network Nb by a link Lbn, which is a physical line. For example, a communication device Nb1 exists in the network Nb. Assume that the MAC address of the communication device Nb1 is "bb-bb-bb-00-00-11".

A transit device Mc is connected to a network Nc by a link Lcn, which is a physical line. For example, a communication device Nc1 exists in the network Nc. Assume that the MAC address of the communication device Nc1 is "cc-cc-cc-00-00-11".

A communication path is secured between the master device Ma and the transit device Mb by a link Lab, which is a physical line connecting the ring port pa1 of the master device Ma and the ring port pb2 of the transit device Mb.

A communication path is secured between the master device Ma and the transit device Mc by a link Lac, which is a physical line connecting the ring port pa2 of the master device Ma and the ring port pc1 of the transit device Mc.

A communication path is secured between the transit device Mb and the transit device Mc by a link Lbc, which is a physical line connecting the ring port pb1 of the transit device Mb and the ring port pc2 of the transit device Mc.

When links Lab, Lbc, and Lac are formed between all communication devices Ma, Mb, and Mc, the network configuration becomes ring-shaped. A data VLAN1 and a data VLAN2 through which user frames flow, and a control VLAN3 through which control frames flow are set by the respective ring ports pa1, pa2, pb1, pb2, pc1, pc2 and links Lab, Lbc, Lac.

The communication path of the ring is controlled by master device 100 . One ring port of the master device Ma is called a primary port, and the other ring port is called a secondary port. A primary port is a ring port that becomes a forwarding state capable of communication when the ring is normal. A secondary port is a ring port that is in a blocking state when the ring is normal. A primary port and a secondary port are controlled for each data VLAN1,2.

In the master device Ma, the ring port pa1 is the primary port 111 and the ring port pa2 is the secondary port 121 in the data VLAN1, and the ring port pa2 is the primary port 122 and the ring port pa1 is the secondary port 112 in the data VLAN2.

Correspondingly, in the data VLAN 1 , the ring port pb 2 of the transit device Mb becomes the primary port 113 and the ring port pb 1 becomes the primary port 115 . Also, in the data VLAN2, the ring port pb2 of the transit device Mc becomes the primary port 114, and the ring port pb1 becomes the primary port 116. FIG.

Similarly, in VLAN 1 , the ring port pc 2 of the transit device Mc becomes the primary port 117 and the ring port pc 1 becomes the primary port 119 . Also, in VLAN2, the ring port pc2 of the transit device Mc becomes the primary port 118, and the ring port pc1 becomes the primary port 120. FIG.

One of the two data VLANs, data VLAN1 and data VLAN2, operates as an active FDB and the other as a standby FDB. Communication between the communication devices Ma, Mb, Mc and the networks Na, Nb, Nc is performed in VLAN1. Each of the communication devices Ma, Mb, and Mc switches the active FDB by converting the VLAN tag of the user frame.

(1-2) Configuration of Communication Device Belonging to Ring FIG. 2 is a block diagram showing an example of the module configuration of the communication device 200 (master device Ma and transit devices Mb and Mc) according to the first embodiment. The communication device 200 physically includes a memory 210, a CPU (Central Processing Unit) 220, a CAM (Content Addressable Memory) 230, a data transfer system ASIC (Application Specific Integrated Circuit) 240, an encapsulation system ASIC 250, and ports 261 to 265. be done.

The memory 210 stores programs executed by the CPU 220 . CPU 220 executes programs stored in memory 210 . The CAM 230 has a function of storing the FDB and executing FDB searches at high speed. The data transfer system ASIC 240 is mainly responsible for transferring frames. Encapsulation system ASIC 250 is responsible for frame encapsulation and decapsulation.

Ports 261 to 265 are interfaces with the outside of the communication device 200 and perform frame transmission/reception with other communication devices 200 . Of the ports 261 to 265, ports 261 and 262 are ring ports, and ports 263 to 265 are extra-ring ports. For example, when communication device 200 is master device Ma, port 261 corresponds to port Pa1, port 262 corresponds to port Pa2, and one of ports 263 to 265 corresponds to port Pa3.

When the communication device 200 is the transit device Mb, the port 261 corresponds to the port Pb1, the port 262 corresponds to the port Pb2, and one of the ports 263 to 265 corresponds to the port Pb3. When the communication device 200 is the transit device Mc, the port 261 corresponds to the port Pc1, the port 262 corresponds to the port Pc2, and one of the ports 263 to 265 corresponds to the port Pc3.

The physical components described above perform the following functions required for the first embodiment. A ring control program 211 and a device management program 214 are developed in the memory 210 . The FDBs held by the CAM 230 logically include two FDBs 231 and 232 . The FDBs 231 and 232 have as entries pairs of the port number of the port for transfer to the transfer destination and the MAC address of the transfer destination. The transfer system ASIC 240 has a transfer engine 241 . The encapsulation system ASIC 250 has a frame encapsulation/decapsulation function 251 .

Each component will be described in detail below. Note that the description will be made with the “program” as the subject (subject of action), but since the program is executed by the processor and performs predetermined processing using memory and ports, the description may be with the processor as the subject.

The ring control program 211 has a ring load control program 212 and an FDB control program 213 . The ring load control program 212 monitors the ring status and controls the ring configuration according to traffic volume information. The FDB control program 213 manages the entries of the FDBs 231 and 232 registered in the CAM 230 . Specifically, the transfer engine 241 constructs a standby FDB and uses the VLAN tag conversion function 242 of the transfer engine 241 to control the FDB referred to in transferring the user frame.

The device management program 214 controls the transfer engine 241 and the link states of the ports 261-265. FDBs 231 and 232 held by the CAM 230 are FDBs for data VLAN1 and data VLAN2, respectively. One FDB is an active FDB and the other FDB is a standby FDB.

The forwarding engine 241 performs MAC address learning, MAC address clearing, and frame forwarding. The transfer engine 241 also has a VLAN tag conversion function 242 and a MAC address notification function 243 . When the transfer engine 241 receives the frame, it searches the active FDB of the CAM 230 to check whether the source MAC address of the received frame is registered in the active FDB. If not registered in the active FDB, the source MAC address is registered in the active FDB (MAC address learning).

The transfer engine 241 also searches the active FDB for the destination MAC address of the received frame, and transfers the frame according to the registered information. The MAC address registered in the active FDB has a limited retention time, and is deleted when the retention time expires (MAC address clear). Note that the MAC address clearing can also be executed by a route change using a ring protocol or by a user's operation.

The VLAN tag conversion function 242 rewrites the VLAN tag of the frame transferred by the transfer engine 241 . The destination VLAN ID of the VLAN tag converted by the VLAN tag conversion function 242 becomes the active FDB. The FDB control program 213 of the ring control program 211 determines the active FDB using the VLAN tag conversion function 242 .

During MAC address learning and MAC address clearing, the MAC address notification function 243 notifies the CPU 220 (FDB control program 213 of the ring control program 211) of the target MAC address for MAC address learning or MAC address clearing.

The frame encapsulation/decapsulation function 251 adds headers to user frames received at the ring ports 261 and 262 and user frames transmitted from the ring ports 261 and 262 in order to measure the amount of traffic flowing through the ring. or remove the header. Also, the frame encapsulating/decapsulating function 251 acquires the statistics of each route from the information attached to the user frame.

FIG. 3 is an explanatory diagram showing an example of the FDB held by the communication device 200 after MAC address learning is completed. (A) shows the FDBs 231 and 232 in the master device Ma (hereinafter referred to as FDBs 231a and 232a). (B) shows the FDBs 231 and 232 in the transit device Mb (hereinafter referred to as FDBs 231b and 232b). (C) shows the FDBs 231 and 232 in the transit device Mc (hereinafter referred to as FDBs 231c and 232c). Assume that the data VLAN1 is the active FDBs 231a, 231b, and 231c, and the data VLAN2 is the standby FDBs 232a, 232b, and 232c.

(1-3) Control Frame FIG. 4 is an explanatory diagram showing the format of a control frame according to the first embodiment. The control frame 401 is used to transmit information related to ring control between communication devices forming a ring. The control frame 401 includes DMAC (Destination Media Access Control) address 403, SMAC (Step Source Media Access Control) address 404, VLAN tag 405, EtherType 406, Ring ID 407, Type 408, Sequence number 409, Data area 410, FCS (Frame Check Sequence) 411.

The DMAC address 403 stores the MAC address of the transmission destination, and the SMAC address 404 stores the MAC address of the transmission source. The VLAN tag 405 stores the VLAN ID of the control VLAN3 designated as the transfer destination of the control frame. EtherType 406 stores a number for identifying a higher-level protocol, and control frame 401 stores information indicating a ring protocol.

The ring ID 407 stores an ID that uniquely identifies the ring to which the control frame 401 belongs. When multiple ring IDs are set in one communication device 200, the control frame 401 is used to identify the ring to be controlled.

The type 408 stores the type 312 of the control frame 401 . Sequence number 409 stores a sequence number indicating the transmission order of control frame 401 . Information 313 corresponding to the type of the control frame 401 is stored in the data area 410 . The FCS 411 stores data added to check for errors in the received frame.

The type 408 stores standby MAC address addition 414 , standby MAC address deletion 415 , and switching instruction 416 . In the control frame 401 having MAC address addition 414 or MAC address deletion 415 stored in the type 408 , the MAC address is stored in the data area 410 . The MAC addresses stored in the data area 410 are used to construct the standby FDBs 232a, 232b, and 232c.

The control frame 401 having the switching instruction 416 stored in the type 408 stores the VLAN ID in the data area 410 . The VLAN ID stored in the data area 410 is the VLAN ID of the FDB to be used after switching.

(1-4) Overall Processing When switching the primary port of the master device Ma in the ring configuration, the network system 100 constructs the FDB after switching as a standby FDB before switching, and processes user frames flowing through the ring. It is to switch the active FDB used for transfer to the standby FDB. The processing of the entire ring network (sequence between devices) will be outlined below.

When starting operation of the ring network, the communication device 200 determines an active FDB and a standby FDB for forwarding user frames. The initial value (value at the start of ring network operation) of each VLAN ID of the active FDB and the standby FDB may be any method as long as it is the same value for all the communication devices Ma, Mb, Mb. The method may be set by the user to the communication device 200, or may be determined by the master device Ma.

The communication device 200 constructs the standby FDB when learning the MAC address or clearing the MAC address. The corresponding communication device 200 notifies the other communication devices 200 of the control frame 401 including the learned or cleared MAC address.

The control frame 401 including the learned MAC address is a control frame including the learned MAC address in the data area 410 of the additional standby MAC address 414 of the type 408 (hereinafter referred to as the "control frame of the additional standby MAC address 414"). .) 401. The control frame 401 including the cleared MAC address is a control frame including the cleared MAC address in the data area 410 of the standby MAC address deletion 415 of the type 408 (hereinafter referred to as "control frame of the standby MAC address deletion 415"). .) 401.

The communication device 200 that has received the control frame 401 registers (in the case of learning) or deletes (in the case of clearing) the notified MAC address in the standby system FDB. The processing after receiving the control frame 401 differs between the master device Ma and the transit devices Mb and Mc.

All the communication devices Ma, Mb, and Mc forming the ring network use the frame encapsulation/decapsulation function 251 to measure the amount of traffic flowing through the ring. The traffic volume measured by each communication device Mb, Mc is collected by the master device Ma. The master device Ma determines whether or not it is necessary to switch the primary port based on the amount of traffic.

Master device Ma transmits control frame 401 of primary port (forwarding state) switching instruction 416 to transit devices Mb and Mc. The control frame 401 of the switching instruction 416 is a control frame including the VLAN ID in the data area 410 of the switching instruction 416 of the primary port of type 408 (forwarding state).

The transit devices Mb and Mc switch the active FDB to the FDB specified by the VLAN ID indicated by the control frame 401 . For example, when the active FDBs are the FDBs 231b and 231c of the data VLAN1 and the VLAN ID indicated by the control frame 401 is "2", the transit devices Mb and Mc switch the active FDBs to the FDBs 232b and 232c of the data VLAN2. . In the following, the processing of the entire ring network (sequence between devices) in the construction of the standby FDB and the communication path switching will be described in detail.

Assume that the active FDB is the FDB 231 of the data VLAN1, and the standby FDB is the FDB 232 of the data VLAN2. That is, in the master device Ma, when the active FDB is in data VLAN1, the secondary port of the active FDB is ring port pa2, and when the active FDB is in data VLAN2, ring port pa1.

(1-4-1) MAC address learning and MAC address clearing in master device Ma FIG. 5 is a device-to-device sequence showing processing of the entire ring network when MAC address learning and MAC address clearing are performed at the external ring port of master device Ma. It is a diagram.

The master device Ma registers the MAC address in the active FDB (FDB 231a) by MAC address learning at the external ring port pa3 of the master device Ma, or deletes the MAC address from the active FDB (FDB 231a) by clearing the MAC address (step S501). ).

When the MAC address is registered or deleted (step S501), the master device Ma registers the MAC address in the standby FDB (FDB 232a) or deletes the MAC address from the standby FDB (FDB 232a) (step S502). The master device Ma blocks the control frame 401 (hereinafter referred to as the control frame 504) of the standby MAC address addition 414 or the standby MAC address deletion 415 in the data VLAN 1 specified by the active FDB (FDB 231a). It is transmitted from the secondary port 121 (pa2) (step S503).

The reason for transmitting the control frame 504 from the secondary port 121 (pa2) is that the secondary port 121 (pa2) of the active FDB (FDB 231a) becomes the primary port 122 after the communication path switching. A control frame 504 for constructing an FDB is transmitted from the secondary port of the active FDB in order to construct an FDB capable of frame transfer using a port that becomes communicable after the communication path switching.

The transit device Mc that received the control frame 504 registers the notified MAC address in the standby system FDB (FDB 232c) or deletes it from the standby system FDB (FDB 232c) (step S505).

When the MAC address is registered or deleted (step S505), the transit device Mc transmits the control frame 504 (hereinafter, control frame 507) from the ring port pc2 (117) different from the received ring port pc1 (119). Send (step S506).

The transit device Mb that receives the control frame 504 registers the notified MAC address in the standby system FDB (FDB 232b) or deletes it from the standby system FDB (FDB 232b) (step S508).

When the MAC address is registered or deleted (step S508), the transit device Mb sends the control frame 507 (hereinafter, control frame 510) from the ring port pb1 (113) different from the received ring port pb1 (115). Transfer (step S509). The control frame 510 finally reaches the master device Ma. Master device Ma discards control frame 510 received at ring port pa1 (111) (step S511). As a result, the FDBs 231a and 232a of the master device Ma are constructed as shown in FIG. 3A.

(1-4-2) MAC address learning and MAC address clearing in transit device FIG. 6 is an inter-device sequence showing processing of the entire ring network when MAC address learning and MAC address clearing are performed at the out-ring port pc3 of the transit device Mc. It is a diagram. The transit device Mc registers the MAC address in the working FDB (FDB 231c) by MAC address learning at the external ring port pc3, or deletes the MAC address from the working FDB (FDB 231c) by clearing the MAC address (step S601).

When the MAC address is registered or deleted (step S601), the transit device Mc registers the MAC address in the standby FDB (FDB 232c) or deletes the MAC address from the standby FDB (step S602). Then, the transit device Mc transmits a control frame 401 for standby MAC address addition 414 or standby MAC address deletion 415 (hereinafter, control frames 604 and 605) from all ring ports pc1 and pc2 of its own device Mc (step S603).

However, although the transit device Mc distributes MAC addresses from all ring ports pc1 and pc2 of its own device Mc, it uses control VLAN3 to transmit control frames 604 and 605 from all ring ports pc1 and pc2. Therefore, transmission of control frames 604 and 605 from all ring ports pc1 and pc2 does not correspond to flooding.

The transit device Mb that has received the control frame 605 registers the notified MAC address in the standby system FDB (FDB 232b) or deletes it from the standby system FDB (FDB 232b), as in (1-4-1) described above (step S606). ).

When the MAC address is registered or deleted (step S606), the transit device Mb sends the control frame 605 (hereinafter, control frame 608) from the ring port pb1 (113) different from the received ring port pb1 (115). Transfer (step S607).

When the receiving port of the master device Ma that receives the control frames 604 and 608 is the secondary port (blocking state) of the active FDB (FDB 231a), the master device Ma registers the MAC address in the standby FDB (FDB 232a) or registers the MAC address in the standby FDB (FDB 232a). Delete from (FDB 232a) (step S609). If the receiving port is the primary port (forwarding state) of the data VLAN specified by the active FDB (FDB 231a), the control frame 401 is discarded (step S610). As a result, as shown in FIGS. 3B and 3C, the FDBs 231b and 232b of the transit device Mb and the FDBs 231c and 232c of the transit device Mc are constructed.

(1-4-4) Communication Path Switching FIG. 7 is an inter-device sequence diagram showing the processing of the entire ring network when the communication path is switched. The amount of traffic flowing through some paths is close to the bandwidth of the port, and there are cases where the paths through which traffic flows are uneven.

The master device Ma determines that it is necessary to switch the communication path in order to smooth the traffic due to the change in ring configuration. In that case, first, the master device Ma switches the active FDB (step S701). Specifically, for example, the VLAN ID of the data VLAN is switched. Details will be described later in (1-5-5).

Next, the master device Ma transmits the control frame 401 (hereinafter referred to as control frame 703) of the switching instruction 416 from all ring ports (pa1 and pa2) (step S702). However, in FIG. 7, the transmission of the control frame 703 from the ring port pa2 by the master device Ma is omitted for the sake of explanation. Upon receiving the control frame 703, the transit device Mb switches the active FDB to the FDB of the VLAN ID indicated by the control frame 703 (step S704). Details will be described later in (1-5-6).

Next, transit device Mb transfers control frame 703 (hereinafter referred to as control frame 706) from a ring port other than the port that received control frame 703 (step S705). The transit device Mc that received the control frame 706 switches the active FDB to the FDB of the VLAN ID indicated by the control frame 706 (step S707). Details will be described later in (1-5-6).

Next, transit device Mb transfers control frame 706 (hereinafter referred to as control frame 709) from a ring port different from the port that received control frame 706 (step S708). Finally, the control frame 709 is returned to the master device Ma, but the master device Ma discards the control frame 709 (step S710).

(1-5) Example of Processing in Communication Apparatus 200 Next, a sequence in the communication apparatus 200 will be described.

(1-5-1) MAC Address Learning FIG. 8 is a sequence diagram in communication apparatus 200 during MAC address learning. FIG. 8 shows the details of the processing from S501 to S503 in FIG. 5 and from S601 to S603 in FIG. The communication device 200 receives user frames at ports 261 to 265, and the transfer engine 241 registers the port numbers and MAC addresses of the received ports in the active FDB (step S801).

After transferring the user frame (step S802), the transfer engine 241 notifies the registered MAC address to the CPU (ring control program 211) 220 (step S803). The CPU (FDB control program 213 of the ring control program 211) 220 confirms whether the ports that have learned the MAC address in step S801 are the ring ports 261 and 262 (step S804). If it is the ring port 261 or 262 (step S804: Yes), no processing is performed.

If the port that learned the MAC address is not the ring ports 261, 262 (step S804: No), the CPU (FDB control program 213 of the ring control program 211) 220 acquires the port number and MAC address of the port that received the user frame. is registered in the standby FDB (step S805).

Next, the CPU (FDB control program 213 of the ring control program 211) 220 confirms the role of the communication device 200 (step S806). When the communication device 200 is the master device Ma (step S806: master), the CPU (the FDB control program 213 of the ring control program 211) 220 starts from the secondary port (blocking state) of the active VLAN registered in step S805. The control frame 401 of the standby system MAC address addition 414 including the MAC address in the data area 410 is transmitted (step S807).

If the communication device 200 is a transit device Mb, Mc (step S806: transit), the CPU (FDB control program 213 of the ring control program 211) 220 transmits the MAC registered in step S805 from all the ring ports 261, 262. The control frame 401 of the standby system MAC address addition 414 including the address in the data area 410 is transmitted (step S808).

(1-5-2) MAC Address Clearing FIG. 9 is a sequence diagram within the communication apparatus 200 when clearing the MAC address. FIG. 9 shows the details of the processing from S501 to S503 in FIG. 5 and from S601 to S603 in FIG. The communication device 200 detects expiration of the MAC address holding time in the transfer engine 241, or a route change by the ring protocol (including reception of a control frame for standby MAC address deletion 415 from the external ring port), or a deletion operation by the user. (step S901).

When the MAC address retention time expires or a deletion operation is detected (step S901), the transfer engine 241 deletes the MAC address from the active FDB (step S902), and clears the MAC address to the CPU (ring control program 211) 220. is notified (step S903).

The CPU (FDB control program 213 of the ring control program 211) 220 confirms whether the ports corresponding to the MAC address cleared deleted in step S902 (MAC address cleared ports) are the ring ports 261 and 262 (step S904). If it is the ring ports 261 and 262 (step S904: Yes), nothing is processed.

On the other hand, if the ports whose MAC addresses have been cleared are not the ring ports 261 and 262 (step S904: No), the CPU (FDB control program 213 of the ring control program 211) 220 obtains the port numbers of the ports whose MAC addresses have been cleared from the standby FDB. And the cleared MAC address is deleted (step S905).

Next, the CPU (ring control program 211) 220 confirms the role of the communication device 200 (step S906). If the communication device 200 is the master device Ma (step S906: master), the CPU (FDB control program 213) 220 stores the cleared MAC address in the data area from the secondary port (blocking state) of the active FDB. The control frame 401 of the standby system MAC address deletion 415 included in 410 is transmitted (step S907). If the communication device 200 is a transit device Mb or Mc (step S906: transit), the CPU (ring control program 211) 220 stores the cleared MAC address in the data area 410 from all ring ports 261 and 262. The control frame 401 of the standby system MAC address deletion 415 is transmitted (step S908).

(1-5-3) Reception of Control Frame 401 for Standby System MAC Address Addition 414 FIG. FIG. 10 shows the details of the processing in steps S505 to S506, S508 to S509 and S511 in FIG. 5 and S606 to S607 and S609 to S610 in FIG.

Upon receiving the control frame 401 for standby system MAC address addition 414, the transfer engine 241 transfers the control frame 401 for standby system MAC address addition 414 to the CPU (ring control program 211) 220 (step S1001). The CPU (FDB control program 213 of the ring control program 211) 220 confirms the role of the communication device 200 (step S1002).

If the communication device 200 is the master device Ma (step S1002: master), the CPU (FDB control program 213 of the ring control program 211) 220 determines the type of the port that received the control frame 401 of the standby MAC address addition 414. Confirm (step S1003).

If the type of the port that received the control frame 401 of the standby system MAC address addition 414 is the primary port (forwarding state) of the active system FDB (step S1003: primary port), the CPU (FDB control program 213 of the ring control program 211) 220 discards the MAC address addition 414 control frame 401 (step S1004).

If it is the secondary port (blocking state) (step S1003: secondary port), the CPU (FDB control program 213 of the ring control program 211) 220 adds the AMAC contained in the data area 410 of the control frame 401 of the standby MAC address addition 414. The address is registered in the standby FDB (step S1005).

CPU (FDB control program 213 of ring control program 211) 220 confirms the role of communication device 200 (step S1002). The CPU (FDB control program 213 of the ring control program 211) 220 registers the MAC address included in the data area 410 of the control frame 401 of the standby system MAC address addition 414 in the standby system FDB (step S1006).

Next, the CPU (FDB control program 213 of the ring control program 211) 220 transmits the control frame 401 of the standby system MAC address addition 414 from the ring port that is not the port that received the control frame 401 of the standby system MAC address addition 414. (step S1007).

(1-5-4) Receipt of Control Frame 401 for Standby System MAC Address Deletion 415 FIG. FIG. 11 shows the details of the processing from S505 to S506 and from S508 to S509 in FIG. 5 and from S606 to S607 and from S609 to S610 in FIG.

Upon receiving the control frame 401 for the standby system MAC address deletion 415, the transfer engine 241 transfers the control frame 401 for the standby system MAC address deletion 415 to the CPU (ring control program 211) 220 (step S1101). The CPU (FDB control program 213 of the ring control program 211) 220 confirms the role of the communication device 200 (step S1102). If the communication device 200 is the master device Ma (step S1102: master), the CPU (FDB control program 213 of the ring control program 211) 220 determines the type of the port that received the control frame 401 of the standby MAC address deletion 415. Confirm (step S1103).

If the type of the port that received the control frame 401 of the standby system MAC address deletion 415 is the primary port (forwarding state) of the active FDB (step S1103: primary port), the CPU (ring control program 211) 220 executes the standby system The control frame 401 for MAC address deletion 415 is discarded (step S1104). If it is the secondary port (blocking state) (step S1103: secondary port), the CPU (FDB control program) 220 deletes the MAC address and its port number existing in the data area 401 of the standby system MAC address deletion 415 from the standby system FDB. Delete (step S1105).

As a result of confirming the role of the communication device 200 (step S1102), if it is a transit device (step S1102: transit), the CPU (FDB control program) 220 deletes the data area 401 of the standby system MAC address deletion 415 from the standby system FDB. delete the MAC address existing in (step S1106). Next, the CPU (FDB control program) 220 transmits the control frame 401 for the standby MAC address deletion 415 from the ring port that is not the port that received the control frame 401 for the standby MAC address deletion 415 (step S1107).

(1-5-5) Communication Path Switching Process in Master Device Ma FIG. 12 is a sequence diagram in the master device Ma at the time of communication path switching according to the first embodiment. FIG. 12 shows the details of the processing from S701 to S702 in FIG. First, the CPU (the ring load control program 212 of the ring control program 211) 220 determines the switching timing of the primary port (forwarding state) (step S1201). The CPU (FDB control program 213) 220 sets VLAN tag conversion and switches the active FDB (step S1202). Details of the switching process of the active FDB will be described in (1-5-8). After that, the CPU (FDB control program 213) 220 transmits the control frame 401 of the switching instruction 416 (step S1203).

(1-5-6) Reception of Control Frame 401 of Switching Instruction 416 FIG. 13 is a sequence diagram in the communication apparatus 200 when receiving the control frame 401 of the switching instruction 416 according to the first embodiment. FIG. 13 shows the details of the processing in steps S704 to S705, S707 to S708, and S710 in FIG. Upon receiving the control frame 401 of the switching instruction 416, the transfer engine 241 transfers the control frame 401 of the switching instruction 416 to the CPU (ring control program 211) 220 (step S1301).

The CPU (FDB control program 213 of the ring control program 211) 220 confirms the role of the communication device 200 (step S1302). If the communication device 200 is the master device Ma (step S1302: master), the CPU (FDB control program 213 of the ring control program 211) 220 discards the control frame 401 of the switching instruction 416 (step S1303).

If the communication device 200 is a transit device Mb, Mc (step S1302: transit), the CPU (FDB control program 213 of the ring control program 211) 220 confirms the FDB of the switching destination (step S1304). When the switching destination FDB is the standby system (step S1304: standby system), the CPU (FDB control program 213) 220 sets VLAN tag conversion, and switches the active FDB to the VLAN instructed by the control frame 401 of the switching instruction 416. Switch to the ID VLAN (step S1305).

Details of the switching process of the active FDB will be described in (1-5-8). After that, the CPU (FDB control program 213) 220 transmits the control frame 401 of the switching instruction 416 from the ring port that is not the port that received the control frame 401 of the switching instruction 416 (step S1306). If the FDB to be switched to is the active system (step S1304: active system), the CPU (FDB control program 213) 220 receives the control frame of the switching instruction 416 from the ring port that is not the port that received the control frame 401 of the switching instruction 416. 401 is transmitted (step S1307).

(1-5-7) User Frame Transfer Since the communication apparatus 200 of the first embodiment duplicates the FDB with two data VLANs, the VLAN IDs of the external ring ports 263 to 265 and the ring ports 261 and 262 do not match. Sometimes. Therefore, some patterns for transferring user frames require VLAN tag conversion. There are eight user frame transfer patterns as follows.

1. When the extra-ring ports 263 to 265 and the ring ports 261 and 262 have different VLAN IDs, the communication device 200 transfers user frames from the extra-ring ports 263 to 265 to the ring ports 261 and 262 .

2. When the VLAN IDs of the extra-ring ports 263-265 and the ring ports 261, 262 are different, the communication device 200 transfers user frames from the ring ports 261, 262 to the extra-ring ports 263-265.

3. When the VLAN IDs of the extra-ring ports 263-265 and the ring ports 261 and 262 are different, the communication device 200 transfers user frames from the extra-ring ports 263-265 to the extra-ring ports 263-265.

4. When the extra-ring ports 263 to 265 and the ring ports 261 and 262 have different VLAN IDs, the communication device 200 transfers user frames from the ring ports 261 and 262 to the ring ports 261 and 262 .

5. When the VLAN IDs of the extra-ring ports 263 to 265 and the ring ports 261 and 262 are the same, the communication device 200 transfers user frames from the extra-ring ports 263 to 265 to the ring ports 261 and 262 .

6. When the extra-ring ports 263-265 and the ring ports 261, 262 have the same VLAN ID, the communication device 200 transfers the user frame from the ring ports 261, 262 to the extra-ring ports 263-265.

7. When the VLAN IDs of the extra-ring ports 263-265 and the ring ports 261 and 262 are the same, the communication device 200 transfers user frames from the extra-ring ports 263-265 to the extra-ring ports 263-265.

8. When the extra-ring ports 263 to 265 and the ring ports 261 and 262 have the same VLAN ID, the communication device 200 transfers the user frame from the ring ports 261 and 262 to the ring ports 261 and 262 .

Of the user frame transfer patterns 1 to 8, the user frame transfer patterns 4 to 8 do not require VLAN tag conversion during frame transfer, and are the same as general frame transfer, so the description is omitted. Sequences in the communication apparatus 200 for user frame transfer patterns 1 to 3 will be described with reference to FIGS. 14 to 16. FIG.

FIG. 14 is a sequence diagram in communication apparatus 200 in user frame transfer pattern 1. As shown in FIG. Here, a case will be described where user frames are transferred from the external ring ports 263 to 265 belonging to data VLAN1 to the ring ports 261 and 262 belonging to data VLAN2.

The transfer engine 241 converts the VLAN tag 405 of the user frame received at the extra-ring ports 263 to 265 from data VLAN1 to data VLAN2 (step S1401). The transfer engine 241 refers to the FDB 232 of the data VLAN2 after conversion, and identifies the destination MAC address of the user frame and the port numbers of the ring ports 261 and 262 (step S1402). As a result, the transfer engine 241 transfers the user frames received by the extra-ring ports 263 to 265 belonging to the data VLAN1 to the ring ports 261 and 262 belonging to the data VLAN2.

FIG. 15 is a sequence diagram in communication apparatus 200 in user frame transfer pattern 2. As shown in FIG. Here, a case will be described where user frames are transferred from the ring ports 261 and 262 belonging to the data VLAN2 to the extra-ring ports 263 to 265 belonging to the data VLAN1.

The transfer engine 241 refers to the FDB 232 of the data VLAN 2 before conversion for the user frames received at the ring ports 261 and 262, and identifies the MAC address of the destination of the user frame and the port numbers of the external ring ports 263 to 265 ( step S1501). Transfer engine 241 converts VLAN tag 405 from data VLAN2 to data VLAN1, and transfers the user frame after conversion of VLAN tag 405 to extra-ring ports 263 to 265 (step S1502).

FIG. 16 is a sequence diagram in communication apparatus 200 in user frame transfer pattern 3. As shown in FIG. Here, a case will be described in which user frames are transferred from the extra-ring ports 263 to 265 belonging to the data VLAN1 to other extra-ring ports 263 to 265 belonging to the data VLAN1.

The transfer engine 241 converts the VLAN tag 405 of the user frame received at the extra-ring ports 263 to 265 from data VLAN1 to data VLAN2 (step S1601). The transfer engine 241 refers to the FDB 232 of the data VLAN2 after conversion in step S1601, and identifies the MAC address of the destination of the user frame and the port numbers of the external ring ports 263 to 265 (step S1602). The transfer engine 241 again converts the VLAN tag 405 from the data VLAN2 to the data VLAN1, and transfers the user frame to the extra-ring ports 263 to 265 identified in step S1602 (step S1603).

(1-5-8) Switching of Active FDB FIG. 17 is an internal sequence of switching processing of the active FDB. The active FDB switching process is the process in S701, S704, and S707 in FIG. 7 and S1811 in FIG. 18 to be described later.

When switching the active FDB, the CPU (FDB control program 213 of the ring control program 211) 220 enables the transfer engine 241 to learn the MAC address of the active FDB after switching and monitor the MAC address holding time. (Step S1701). Next, the CPU (FDB control program 213 of the ring control program 211) 220 disables the MAC address learning and MAC address holding time monitoring of the standby FDB after switching to the transfer engine 241 (step S1702). .

After that, the CPU (FDB control program 213 of the ring control program 211) 220 confirms the VLAN ID of the active FDB after switching (step S1703). If the VLAN ID of the active FDB after switching matches the VLAN IDs of the external ring ports 263 to 265 (step S1703: match), the CPU (FDB control program 213 of the ring control program 211) 220 sets the VLAN of the transfer engine 241. For the tag conversion function 242, the VLAN tag conversion for reception and transmission of the external ring ports 263 to 265 is disabled (step S1704).

If the VLAN ID of the active FDB after switching does not match the VLAN IDs of the external ring ports 263 to 265 (step S1703: mismatch), the CPU (FDB control program 213 of the ring control program 211) 220 changes the transfer engine 241 For the VLAN tag conversion function 242, the VLAN ID of the VLAN tag conversion destination at the time of reception of the external ring ports 263 to 265 is set to the VLAN ID of the active FDB after switching (step S1705).

Next, the CPU (FDB control program 213 of the ring control program 211) 220 sends the VLAN ID of the VLAN tag conversion destination of the transmission of the external ring ports 263 to 265 to the VLAN tag conversion function 242 of the transfer engine 241 as the external ring port. 263 to 265 are set (step S1706). After performing this processing, the standby FDB after switching continues operation while retaining the FDB when it was the active system.

[1] As described above, the communication device 200 according to the first embodiment includes a storage unit (CAM 230) and a control unit (ring control program 211). The storage unit (CAM 230) stores first transfer destination information (FDB 231) capable of registering a combination of MAC address and port number for the first virtual network (data VLAN 1) through which user frames are transmitted and received within the ring network, and second transfer destination information (FDB 232) capable of registering a combination of a MAC address and a port number for a second virtual network (data VLAN 2) through which user frames are transmitted and received. When the control unit (ring control program 211) switches the active virtual network from the first virtual network (data VLAN1) to the second virtual network (data VLAN2), the transfer destination information applied to the active virtual network. is switched from the first transfer destination information (FDB 231) to the second transfer destination information (FDB 232).

As a result, since the second forwarding destination information (FDB 232) has already been constructed before switching, when changing the blocking port, flooding is not generated when switching the communication path (active virtual network), and the traffic volume is reduced. can be suppressed.

[2] In the communication device 200 of [1] above, the control unit (ring control program 211) controls the ring network within the ring network when the own device 200 is the master device Ma that manages the communication device group. Using the third virtual network (control VLAN 3) in which the frame 401 is transmitted/received, the control frame 703 including the transfer destination information switching instruction (identification information (for example, VLAN ID) of the switching destination virtual network) is transmitted to the other of the transfer destination. to the communication device (transit device Mb).

Thereby, the transit device Mb can switch the transfer destination information applied to the active virtual network from the first transfer destination information (FDB231) to the second transfer destination information (FDB232).

[3] In the communication device 200 of [2] above, when the control unit (ring control program 211) receives the control frame 709 including the switching instruction at the primary port in the active virtual network, the control including the switching instruction is performed. Discard frame 709 .

This can prevent endless circulation of the control frame 709 containing the switching instruction.

[4] In the communication device 200 of [1] above, the control unit (ring control program 211) uses the third virtual network (control VLAN 3) in which the control frame 401 for controlling the ring network is transmitted and received within the ring network. , when a control frame (703, 706) containing a switching instruction of transfer destination information generated by the master device Ma managing the communication device group is received, the transfer destination information applied to the active virtual network is transferred to the first transfer While switching from the destination information (FDB 231) to the second transfer destination information (FDB 232), the control frames (703, 706) including the switching instruction are transmitted to the other communication devices (Mb, Ma) of the transfer destination.

As a result, FDB switching can be realized in each transit device in the ring network.

[5] When the communication device 200 of [1] above receives a frame including a source MAC address from the external ring ports 263 to 265, the combination of the source MAC address and the port numbers of the ports 263 to 265 is It has a learning unit (transfer engine 241) registered in the transfer destination information (FDB 231). The control unit (ring control program 211) registers the result of learning by the learning unit (transfer engine 241) in the second transfer destination information (FDB 232), and a control frame 401 for controlling the ring network is transmitted/received within the ring network. Using the third virtual network (control VLAN 3), a control frame (504, 507, 510) including an instruction to add the learning result to the second transfer destination information (FDB 232) is transmitted to another communication device of the transfer destination. .

As a result, the learning result of the MAC address of the first transfer destination information (FDB 231) of the own device can be reflected in the second transfer destination information (FDB 232) of the own device and other devices before switching the communication path.

[6] In the communication device 200 of [5] above, the control unit (ring control program 211) operates the control frame 401 including the additional instruction when the own device 200 is the master device Ma that manages the communication device group. Send to other communication devices from the secondary port of the virtual network of the system.

As a result, it is possible to construct an FDB capable of frame transfer using a port that becomes communicable after communication path switching.

[7] In the communication device 200 of [5] above, if the own device 200 is the transit device Mb or Mc managed by the master device Ma in the communication device group, the control unit (ring control program 211) gives an additional instruction When a control frame including is received, the learning result is registered in the second transfer destination information (FDB 232).

Thereby, even when a control frame is received from another communication device, the second forwarding destination information (FDB 232) can be learned.

[8] In the communication device 200 of [7] above, the control unit (ring control program 211) transmits a control frame including an addition instruction from all ports in the ring network.

As a result, the learning target MAC address can be distributed using the control frame.

[9] In the communication device 200 of [6] above, when the control unit (ring control program 211) receives the control frame 608 including the addition instruction at the primary port in the active virtual network, the control including the addition instruction Discard frame 608 .

This makes it possible to prevent endless circulation of control frames 608 containing additional instructions.

[10] In the communication device 200 of [6] above, when the control unit (ring control program 211) receives the control frame 608 including the addition instruction at the secondary port in the active virtual network, the second transfer destination information Register the learning result in (FDB 232).

As a result, the second forwarding destination information (FDB 232) can be learned without discarding the control frame 608 including the addition instruction.

[11] When the communication device 200 of [1] above receives a MAC address deletion instruction, the combination of the deletion instruction MAC address and the port number of the port corresponding to the MAC address is stored in the first transfer destination information (FDB 231). It has a learning unit (transfer engine 241) that deletes from. The control unit (ring control program 211) deletes the combination deleted by the learning unit (transfer engine 241) from the second transfer destination information (FDB 232), and transmits and receives a control frame 401 for controlling the ring network within the ring network. Control frames (504, 507, 510, 604, 605, 608) containing deletion instructions for the deleted combination from the second transfer destination information (FDB 232) using the third virtual network (control VLAN 3), Send to other communication device of transfer destination.

As a result, the result of clearing the MAC address of the first transfer destination information (FDB 231) of the own device can be reflected in the second transfer destination information (FDB 232) of the own device and other devices before switching the communication path.

[12] In the communication device 200 of [11] above, the control unit (ring control program 211) sends the control frame 401 including the deletion instruction to the active system when the own device is the master device Ma that manages the communication device group. to the other communication device from the secondary port of the virtual network of

As a result, it is possible to construct an FDB capable of frame transfer using a port that becomes communicable after communication path switching.

[13] In the communication device 200 of [11] above, the control unit (ring control program 211) issues a deletion instruction when the own device is the transit device Mb or Mc managed by the master device Ma in the communication device group. When receiving the control frame 401 including, the deleted combination is deleted from the second forwarding destination information (FDB 232).

Thereby, even when a control frame is received from another communication device, the second forwarding destination information (FDB 232) can be learned.

[14] In the communication device 200 of [13] above, the control unit (ring control program 211) transmits a control frame including a deletion instruction from all ports in the ring network.

As a result, the learning target MAC address can be distributed using the control frame.

[15] In the communication device 200 of [12] above, when the control unit (ring control program 211) receives the control frame 510 including the deletion instruction at the primary port in the active virtual network, the control including the deletion instruction is performed. Discard frame 510 .

This makes it possible to prevent endless circulation of control frames 608 containing deletion instructions.

[16] In the communication device 200 of [12] above, when the control unit (ring control program 211) receives the control frame 510 including the deletion instruction at the secondary port in the active virtual network, the control frame 510 is deleted by the learning unit. delete the combination from the second forwarding destination information (FDB 232).

As a result, the second transfer destination information (FDB 232) can be learned without discarding the control frame 608 containing the deletion instruction.

In the first embodiment, the active FDB is switched from the communication device 200 that receives the control frame 401 of the switching instruction 416 . For this reason, a frame loss occurs from the time the master device Ma switches the communication path and FDB until the end of the switching of the FDBs of all the communication devices 200 in the ring network. Example 2 mitigates this frame loss.

The difference between the first embodiment and the second embodiment is the communication path switching method. In the second embodiment, the time is synchronized between the communication devices 200, and the communication path and active FDB are switched at the same time. The second embodiment will be described in detail, focusing on the differences from the first embodiment.

(2-1) Configuration of Communication Apparatus Belonging to Ring FIG. 18 is a block diagram illustrating a module configuration example of the communication apparatus 200 according to the second embodiment. The device management program 214 has a time management program 1801 . The time management program 1801 manages the time for each communication device 200 and synchronizes the time between the communication devices 200 by NTP (Network Time Protocol) or the like. The ring control program 211 cooperates with the time management program 1801 . Except for the time management program 1801, the module configuration of the communication device 200 is the same as that of the first embodiment.

(2-2) Format Example of Control Frame FIG. 19 is an explanatory diagram of a format example of the control frame 402 according to the second embodiment. In the control frame 402 of the second embodiment, the VLAN ID and the switching time 1902 are stored in the data area 410 of the switching instruction 1901 of the type 408 . Except for this one point, the control frame 402 is the same as the control frame 401 of the first embodiment.

(2-3) Overall Processing The construction method of the standby FDB is the same as the construction method shown in (1-4-1) and (1-4-2) of the first embodiment. The difference between the first embodiment and the second embodiment lies in communication path switching processing. The sequence between the communication devices 200 showing the processing of the entire ring network at the time of path switching will be described in detail below.

(2-3-1) Communication Path Switching FIG. 20 is a sequence diagram between the communication devices 200 showing the processing of the entire ring network at the time of communication path switching according to the second embodiment. If the amount of traffic flowing through some routes is approaching the bandwidth of the port and there is an imbalance in the routes through which the traffic flows, the master device Ma needs to switch communication routes in order to smooth the traffic by changing the ring configuration. to decide. In this case, the master device Ma registers the path switching time (step S2001), and the control frame 402 (hereinafter referred to as the control frame 2003) is transmitted from the ring ports 261 and 262 (step S2002).

Transit device Mb that has received control frame 2003 registers the route switching time (step S2004), and transmits control frame 2003 (hereinafter referred to as control frame 2006) is transmitted (step S2005).

The transit device Mc that received the control frame 2006 registers the route switching time (step S2007), and transmits the control frame 2006 (hereinafter referred to as the control frame 2009) is transmitted (step S2008).

Finally, the control frame 2009 is returned to the master device Ma, but the master device Ma discards the control frame 2009 (step S2010). After that, when the switching time arrives, all the communication devices Ma, Mb, and Mc forming the ring network switch the active FDB to the VLAN indicated by the control frame 402 (step S2011).

(2-4) Processing in Communication Apparatus 200 A sequence in communication apparatus 200 will be described.

(2-4-1) Communication Path Switching Process in Master Device Ma FIG. 21 is a sequence diagram in the master device Ma at the time of communication path switching according to the second embodiment. FIG. 21 shows the details of the processing from S2001 to S2002 and S2011 in FIG. First, the CPU (ring load control program 212 of the ring control program 211) 220 determines the switching timing of the primary port (step S2101).

The CPU (FDB control program 213) 220 sets the switching time in the CPU (time management program 1801 of the device management program 214) 220 (step S2102). After that, the CPU (FDB control program 213) 220 transmits the control frame 402 of the switching instruction 1901 (step S2103).

The CPU (time management program 1801) 220 notifies at the time specified by the CPU (FDB control program 213) 220 (step S2104). The CPU (time management program 1801) 220 that has received the notification sets VLAN tag conversion and switches the active FDB (step S2105). The details of the switching process of the active FDB are as described in (1-5-8) above.

(2-4-2) Reception of Control Frame 402 of Switching Instruction 1901 FIG. 22 is a sequence within the communication apparatus 200 when receiving the control frame 402 of the switching instruction 1901 according to the second embodiment. FIG. 22 shows details of the processing in steps S2004 to S2005, S2007 to S2008, S2010, and S2011 of FIG. Upon receiving the control frame 402 of the switching instruction 1901, the transfer engine 241 transfers the control frame 402 of the switching instruction 1901 to the CPU (ring control program 211) 220 (step S2201).

The CPU (ring control program 211) 220 confirms the role of the communication device 200 (step S2202). If the communication device 200 is the master device Ma (step S2202: master), the CPU (ring control program 211) 220 discards the control frame 402 of the switching instruction 1901 (step S2203).

If the communication device 200 is a transit device (step S2202: transit), the CPU (ring control program 211) 220 checks the switching destination FDB (step S2204). If the switching destination FDB is the standby system (step S2204: standby system), the CPU (ring control program 211) 220 sets the switching time in the CPU (time management program 1801 of the device management program 214) 220 (step S2205). .

After that, the CPU (ring control program 211) 220 transmits the control frame 402 of the switching instruction 1901 from the ring ports 261 and 262 that are not the ports that received the control frame 402 of the switching instruction 1901 (step S2206).

When the switching destination FDB is the active system (step S2204: active system), the CPU (ring control program 211) 220 receives the switching instruction 1901 from the ring ports 261 and 262 that are not ports that received the control frame 402 of the switching instruction 1901. control frame 402 (step S2207).

The CPU (time management program) 220 notifies the CPU (ring control program 211) 220 that the designated switching time has come (step S2208). The CPU (ring control program 211) 220 that has received the notification sets VLAN tag conversion, and switches the active FDB to the VLAN of the VLAN ID indicated by the control frame 402 of the switching instruction 1901 (step S2209). The details of the switching process of the active FDB are as described in (1-5-8) above.

[17] As described above, in the communication device 200 according to the second embodiment, in the communication device 200 of [1] above, the control unit (ring control program 211) sets the active virtual network common to the communication device group as the first virtual network. When the switching time for switching from the first virtual network (data VLAN1) to the second virtual network (data VLAN2) arrives, the forwarding destination information applied to the active virtual network is changed from the first forwarding destination information (FDB 231) to the above-mentioned Switch to the second transfer destination information (FDB 232).

This reduces the frame loss that occurs from the time the master device Ma switches the communication path and FDB until the end of the switching of the FDBs of all the communication devices 200 in the ring network.

[18] In the communication device 200 of [17] above, the control unit (ring control program 211) controls the ring network within the ring network when the own device 200 is the master device Ma that manages the communication device group. Using the third virtual network (control VLAN 3) through which the frame 402 is transmitted/received, the control frame 2003 including the switching instruction and switching time of the transfer destination information is transmitted to another communication device (transit device Mb) as the transfer destination.

As a result, when the switching time arrives, the transit device Mb can switch the transfer destination information applied to the active virtual network from the first transfer destination information (FDB 231) to the second transfer destination information (FDB 232). can.

[19] In the communication device 200 of [18] above, when the control unit (ring control program 211) receives the control frame 2009 including the switching instruction and the switching time at the primary port in the active virtual network, the switching instruction and the control frame 2009 including the switching time is discarded.

This can prevent endless circulation of the control frame 2009 containing the switching instruction and the switching time.

[20] In the communication device 200 of [17] above, the control unit (ring control program 211) uses the third virtual network (control VLAN 3) in which the control frame 402 for controlling the ring network is transmitted and received within the ring network. , when receiving a control frame (2003, 2006) containing a switching instruction and switching time of transfer destination information generated by the master device Ma managing the communication device group, a control frame (2006, 2009) containing a switching instruction and switching time is transmitted to another communication device (Mb, Ma) of the transfer destination before the arrival of the switching time.

As a result, when the switching time arrives, FDB switching can be realized in each transit device in the ring network.

100 network system 200 communication device 211 ring control program 212 ring load control program 213 FDB control program 214 device management program 231, 232 FDB
241 Transfer engine 242 Tag conversion function 243 Address notification function 251 Frame encapsulation/decapsulation function 261 to 265 Ports 401, 402 Control frame 414 Standby system MAC address addition 415 Standby system MAC address deletion 416, 1901 Switching instruction 1801 Time management program

Claims (20)

Any communication device among a group of communication devices constituting a ring network defined by a ring protocol,
First transfer destination information capable of registering a combination of a MAC address and a port number for a first virtual network through which user frames are transmitted and received within the ring network, and a second virtual network through which user frames are transmitted and received within the ring network a storage unit having second transfer destination information in which a combination of a MAC address and a port number can be registered;
When the active virtual network is switched from the first virtual network to the second virtual network, the forwarding destination information applied to the active virtual network is changed from the first forwarding destination information to the second forwarding destination information. a control unit that switches to
A communication device comprising: A communication device according to claim 1,
When one of the communication devices is a master device that manages the communication device group, the control unit uses a third virtual network in which a control frame for controlling the ring network is transmitted and received within the ring network, Transmitting a control frame including an instruction to switch the transfer destination information to another communication device of the transfer destination;
A communication device characterized by: A communication device according to claim 2,
The control unit discards the control frame including the switching instruction when a control frame including the switching instruction is received at a primary port in the active virtual network.
A communication device characterized by: A communication device according to claim 1,
The control unit uses a third virtual network in which a control frame for controlling the ring network is transmitted and received within the ring network, and includes a switching instruction of transfer destination information generated by a master device managing the communication device group. When the control frame is received, the transfer destination information applied to the active virtual network is switched from the first transfer destination information to the second transfer destination information, and the control frame including the switching instruction is transferred to the transfer destination. to other communication devices in
A communication device characterized by: A communication device according to claim 1,
a learning unit that, when receiving a frame including a source MAC address from a port outside the ring network, registers a combination of the source MAC address and the port number of the port in the first transfer destination information;
The control unit registers the result of learning by the learning unit in the second transfer destination information, and uses a third virtual network in which a control frame for controlling the ring network is transmitted and received within the ring network. 2 transmitting a control frame including an instruction to add the learning result to the transfer destination information to another communication device as the transfer destination;
A communication device characterized by: A communication device according to claim 5,
When one of the communication devices is a master device that manages the communication device group, the control unit transmits a control frame including the addition instruction from the secondary port of the active virtual network to the other communication device. Send,
A communication device characterized by: A communication device according to claim 5,
When any one of the communication devices is a transit device managed by a master device in the communication device group, the control unit transfers the learning result to the second transfer destination when receiving the control frame including the additional instruction. register for information,
A communication device characterized by: A communication device according to claim 7,
wherein the control unit transmits a control frame including the additional instruction from all ports in the ring network;
A communication device characterized by: A communication device according to claim 6,
When the control unit receives a control frame including the addition instruction at a primary port in the active virtual network, the control unit discards the control frame including the addition instruction.
A communication device characterized by: A communication device according to claim 6,
The control unit registers the learning result in the second transfer destination information when a control frame including the addition instruction is received at a secondary port in the active virtual network.
A communication device characterized by: A communication device according to claim 1,
a learning unit that, upon receiving a MAC address deletion instruction, deletes from the first transfer destination information a combination of the MAC address of the deletion instruction and the port number of the port corresponding to the MAC address;
The control unit deletes the combination deleted by the learning unit from the second transfer destination information, and uses a third virtual network in which a control frame for controlling the ring network is transmitted and received within the ring network, transmitting a control frame including a deletion instruction of the deleted combination from the second transfer destination information to another communication device of the transfer destination;
A communication device characterized by: 12. A communication device according to claim 11, wherein
When one of the communication devices is a master device that manages the group of communication devices, the control unit transmits a control frame including the deletion instruction from the secondary port of the active virtual network to the other communication device. Send,
A communication device characterized by: 12. A communication device according to claim 11, wherein
When any one of the communication devices is a transit device managed by a master device in the communication device group, the control unit, when receiving a control frame including the deletion instruction, converts the deleted combination to the second Delete from forwarding information,
A communication device characterized by: 14. A communication device according to claim 13, wherein
wherein the control unit transmits a control frame including the deletion instruction from all ports in the ring network;
A communication device characterized by: 13. A communication device according to claim 12,
When the control unit receives a control frame including the deletion instruction at a primary port in the active virtual network, the control unit discards the control frame including the deletion instruction.
A communication device characterized by: 13. A communication device according to claim 12,
The control unit deletes the combination deleted by the learning unit from the second transfer destination information when a control frame including the deletion instruction is received at a secondary port in the active virtual network.
A communication device characterized by: A communication device according to claim 1,
The control unit is applied to the active virtual network when a switching time for switching the active virtual network common to the communication device group from the first virtual network to the second virtual network arrives. switching forwarding destination information from the first forwarding destination information to the second forwarding destination information;
A communication device characterized by: 18. A communication device according to claim 17, wherein
When one of the communication devices is a master device that manages the communication device group, the control unit uses a third virtual network in which a control frame for controlling the ring network is transmitted and received within the ring network, Transmitting a control frame including a switch instruction of transfer destination information and the switch time to another communication device as a transfer destination;
A communication device characterized by: 19. A communication device according to claim 18, wherein
The control unit discards the control frame including the switching instruction and the switching time when a control frame including the switching instruction and the switching time is received at a primary port in the active virtual network.
A communication device characterized by: 18. A communication device according to claim 17, wherein
The control unit uses a third virtual network in which a control frame for controlling the ring network is transmitted and received in the ring network, and instructs switching of transfer destination information generated by a master device that manages the group of communication devices and the When a control frame containing the switching time is received, the control frame containing the switching instruction and the switching time is transmitted to another communication device as a transfer destination before the switching time arrives;
A communication device characterized by:

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