WO2017221357A1

WO2017221357A1 - Relay device

Info

Publication number: WO2017221357A1
Application number: PCT/JP2016/068568
Authority: WO
Inventors: 克佳高橋
Original assignee: 三菱電機株式会社
Priority date: 2016-06-22
Filing date: 2016-06-22
Publication date: 2017-12-28
Also published as: GB2568168A; GB201818272D0; JP6355880B2; JPWO2017221357A1; GB2568168B

Abstract

A storage unit (191) stores a relay table associating transmitter addresses, relay message types, and destination ports with one another. When a frame including a transmitter address and a message has arrived at one of a plurality of communication ports (904), a frame analysis unit (110) acquires, as an analysis message type, the type of the message included in the frame. A relay determination unit (130) selects, from the relay table, one or more destination ports associated with the combination of the transmitter address included in the frame and the relay message type identical to the acquired analysis message type. The relay determination unit then selects, as a transmission port, each of the selected one or more destination ports except for reception ports.

Description

Relay device

The present invention relates to a relay device such as a bridge.

In control networks used in air conditioning systems, etc., in order to respond to the increase in communication volume accompanying the expansion of the system scale and the increase in system functions, bandwidth is suppressed by introducing bridges or implementing monitoring. Yes.

In a system in which a control network is used, exchange of request messages and response messages is often performed periodically in order to monitor the state between devices connected to the control network. Therefore, when the number of devices increases, the number of messages for state monitoring also increases, and it is easy to consume bandwidth.

The bridge determines whether it is necessary to relay the frame based on the destination address, and does not relay the frame to an unnecessary range. This makes it possible to reduce the bandwidth used. Such a band reduction method is called a bridge method.
Patent Document 1 discloses an example of a bridge.

IGMP is defined in RFC1112 of IETF.
IETF is an abbreviation for Internet Engineering Task Force.
RFC is an abbreviation for Request For Comments.
IGMP is an abbreviation for Internet Group Management Protocol.

In IGMP, when a querier among a plurality of queriers transmits a query request and a listener transmits a report response, the other querier receives the report response and does not transmit the query request itself.
In IGMP, queries and reports are multicast.
In the bus type network, data arrives at each terminal even if the data is unicast.
Therefore, in the bus network, it is possible to receive a response without transmitting a request, as in IGMP. That is, each device can receive a request and a response exchanged between other devices and acquire necessary data. Therefore, it is possible to reduce the use band by not transmitting the request by each device. Such a band reduction method is called a monitoring method.

The monitoring method aims to reduce communication between devices in a bus network by monitoring the communication that each device performs between other devices and acquiring the data that the device wants to collect. .
However, when a bridge is introduced, communication between other devices does not reach each device that performs monitoring. Therefore, each device has to transmit a request itself in order to obtain necessary data. As a result, it becomes difficult to obtain a band consumption reduction effect.

Therefore, in order to obtain a band consumption reduction effect even if a bridge is introduced, it is also possible to relay all communications to the bridge by operating the bridge in a “flooding” mode in which filtering is not performed.
However, when the bridge is operated in the “flooding” mode, the band consumption reduction effect by filtering cannot be obtained.

Japanese Patent No. 399469

An object of the present invention is to be able to suppress the use band by using both the bridge method and the monitoring method.

The relay device of the present invention
Multiple communication ports,
A storage unit that stores a relay table in which a source address, a relay message type, and a destination port are associated with each other;
A frame analysis unit that obtains a message type included in the frame as an analysis message type when a frame including a source address and a message arrives at any of the plurality of communication ports;
Select a destination port corresponding to a combination of a source address included in the frame and the same relay message type as the analysis message type from the relay table, and the same destination as the communication port from which the frame arrived from the selected destination port A relay determination unit that selects a remaining destination port excluding the port as a communication port that outputs the frame.

According to the present invention, it is possible to suppress the use band by using both the bridge method and the monitoring method.

1 is a configuration diagram of a relay device 100 according to Embodiment 1. FIG. FIG. 3 is a configuration diagram of a storage unit 191 in the first embodiment. FIG. 3 is a configuration diagram of a first relay table 210 in the first embodiment. FIG. 3 is a configuration diagram of a second relay table 220 in the first embodiment. FIG. 3 is a configuration diagram of a message correspondence table 230 in the first embodiment. FIG. 3 is a configuration diagram of a frame 200 in the first embodiment. 3 is a flowchart of a relay method according to the first embodiment. 5 is a flowchart of relay learning processing (S200) in the first embodiment. 5 is a flowchart of relay determination processing (S300) in the first embodiment. FIG. 2 shows a bus network in Embodiment 1. FIG. 4 shows a first relay table 210 in the first embodiment. FIG. 6 shows a second relay table 220 in the first embodiment. FIG. 4 shows a first relay table 210 in the first embodiment. FIG. 2 shows a bus network in Embodiment 1. FIG. 2 shows a bus network in Embodiment 1. The figure which shows the relay message list 240 in Embodiment 2. FIG. The flowchart of the relay determination process (S300) in Embodiment 2. The figure which shows the relay message table 250 in Embodiment 2. FIG. The flowchart of the relay determination process (S300) in Embodiment 2. 10 is a flowchart of relay learning processing (S200) in the third embodiment. 10 is a flowchart of relay determination processing (S300) in the third embodiment. FIG. 6 shows a bus network in Embodiment 3. The hardware block diagram of the relay apparatus 100 in embodiment.

In the embodiment and the drawings, the same reference numerals are given to the same elements or elements corresponding to each other. Description of elements having the same reference numerals will be omitted or simplified as appropriate.

Embodiment 1 FIG.
The relay device 100 will be described with reference to FIGS.
Specifically, the relay device 100 is a network device called a bridge.

*** Explanation of configuration ***
Based on FIG. 1, the structure of the relay apparatus 100 is demonstrated.
The relay apparatus 100 is a computer including hardware such as a processor 901, a memory 902, and a plurality of network interfaces (903-1, 903-2). These hardwares are connected to each other via signal lines.
The network interface 903-1 and the network interface 903-2 are collectively referred to as a network interface 903.

The processor 901 is an IC (Integrated Circuit) that performs processing, and controls other hardware. Specifically, the processor 901 is a CPU, DSP, or GPU. CPU is an abbreviation for Central Processing Unit, DSP is an abbreviation for Digital Signal Processor, and GPU is an abbreviation for Graphics Processing Unit.
The memory 902 is a volatile storage device. The memory 902 is also called main memory or main memory. Specifically, the memory 902 is a RAM (Random Access Memory).

The network interface 903 is a device that performs communication. Specifically, the network interface 903 is a NIC (Network Interface Card).
A port included in the network interface 903-1 is referred to as a communication port 904-1, and a port included in the network interface 903-2 is referred to as a communication port 904-2.
Communication port 904-1 is connected to network 910-1. Communication port 904-2 is connected to a network 910-2 different from network 910-1.
Communication port 904-1 and communication port 904-2 are collectively referred to as communication port 904. The network 910-1 and the network 910-2 are collectively referred to as a network 910.

The relay apparatus 100 includes “units” such as a frame analysis unit 110, a relay learning unit 120, and a relay determination unit 130 as functional configuration elements. The function of “part” is realized by software. The function of “part” will be described later.

An OS (Operating System) and a program that realizes the function of “unit” are loaded into the memory 902 and executed by the processor 901.
The processor 901 executes a program that realizes the function of “unit” while executing the OS.
Data obtained by executing a program that realizes the function of “unit” is stored in a storage device such as the memory 902, a register in the processor 901, or a cache memory in the processor 901.

The memory 902 functions as a storage unit 191 that stores data used, generated, input, output, transmitted, or received by the relay device 100. However, other storage devices may function as the storage unit 191.
The network interface 903 functions as a receiving unit (192-1, 192-2) that receives data and a transmitting unit (193-1, 193-2) that transmits data.
The receiving unit 192-1 and the receiving unit 192-2 are collectively referred to as a receiving unit 192, and the transmitting unit 193-1 and the transmitting unit 193-2 are collectively referred to as a transmitting unit 193.

The relay apparatus 100 may include a plurality of processors that replace the processor 901. The plurality of processors share execution of a program that realizes the function of “unit”.
A program that realizes the function of “unit” can be stored in a computer-readable manner in a nonvolatile storage medium such as a magnetic disk, an optical disk, or a flash memory. A non-volatile storage medium is a tangible medium that is not temporary.
“Part” may be read as “processing” or “process”. The function of “unit” may be realized by firmware.

Based on FIG. 2, the structure of the memory | storage part 191 is demonstrated.
The storage unit 191 stores a first relay table 210, a second relay table 220, a message correspondence table 230, and the like. These will be described later.

Based on FIG. 3, the structure of the 1st relay table 210 is demonstrated.
The first relay table 210 has an entry corresponding to a record.
The entries included in the first relay table 210 are referred to as first relay entries (211-1, 211-2, 211-3). The first relay entries (211-1, 211-2, 211-3) are collectively referred to as the first relay entry 211.

In the first relay entry 211, the destination address and the destination port are associated with each other.
The destination address is the address of the terminal that is the destination of the frame.
The destination port is a communication port 904 connected to the network 910 to which the destination terminal is connected. A destination port identifier is set in the destination port field. The destination port identifier is an identifier for identifying the destination port.
The first relay entry 211 is registered at any time by the relay learning unit 120.

The first relay table 210 corresponds to an FDB (filtering database).

The configuration of the second relay table 220 will be described based on FIG.
The second relay table 220 has an entry corresponding to a record.
Entries included in the second relay table 220 are referred to as second relay entries (221-1, 212-2). The second relay entries (221-1, 212-2) are collectively referred to as second relay entries 221.

In the second relay entry 221, the transmission source address, the relay message type, and the destination port are associated with each other.
The transmission source address is an address of a terminal that is a transmission source of the frame.
The relay message type is a type of message included in the frame. Specifically, the relay message type is a response message. The response message is a message in response to the request message. The request message is a message requesting a response message.
The destination port is a communication port 904 that is connected to the network 910 to which the terminal that is the destination of the frame is connected. A destination port identifier is set in the destination port field.
The second relay entry 221 is registered at any time by the relay learning unit 120.

The second relay table 220 corresponds to an extended FDB.

Based on FIG. 5, the structure of the message corresponding | compatible table 230 is demonstrated.
The message correspondence table 230 has entries corresponding to records.
Entries included in the message correspondence table 230 are referred to as message correspondence entries (231-1 to 231-3). The message correspondence entries (231-1 to 231-3) are collectively referred to as a message correspondence entry 231.

In the message correspondence entry 231, the first message type and the second message type are associated with each other.
The first message type is a type of message included in the frame. Specifically, the first message type is a request message.
The second message type is a type of message included in the frame. Specifically, the second message type is a response message.

The message correspondence table 230 is generated in advance.

The configuration of the frame 200 will be described with reference to FIG.
The frame 200 includes a transmission source address 201, a destination address 202, a type 203, a message 204, and the like.
The transmission source address 201 is an address of a terminal that is a transmission source of the frame 200.
The destination address 202 is an address of a terminal that is the destination of the frame 200.
A type 203 is a type of the message 204.
Message 204 is a payload. Specifically, the message 204 is a request message or a response message.

*** Explanation of operation ***
The operation of the relay device 100 corresponds to a relay method. The procedure of the relay method corresponds to the procedure of the relay program.

The relay method will be described based on FIG.
Step S110 is a reception process.
In step S110, when the frame 200 arrives at any of the plurality of communication ports 904, the receiving unit 192 corresponding to the communication port 904 from which the frame 200 has arrived receives the arrived frame 200.
The communication port 904 from which the frame 200 has arrived is called a reception port.

Step S120 is a frame analysis process.
In step S120, the frame analysis unit 110 analyzes the received frame 200 to obtain a transmission source address 201, a destination address 202, and an analysis message type.
The analysis message type is a type of the message 204 included in the received frame 200.

Specifically, the frame analysis unit 110 operates as follows.
The frame analysis unit 110 extracts the transmission source address 201 from the received frame 200.
The frame analysis unit 110 extracts the destination address 202 from the received frame 200.
The frame analysis unit 110 extracts the type 203 from the received frame 200. The extracted type 203 is the analysis message type.
If the type 203 is not included in the frame 200, the frame analysis unit 110 obtains an analysis message type by executing an analysis algorithm on the message 204. The analysis algorithm to be executed is a predetermined algorithm for obtaining the analysis message type.

Further, the frame analysis unit 110 obtains a reception port port identifier from the reception unit 192 corresponding to the reception port. The reception port identifier is an identifier for identifying a reception port.

Step S200 is a relay learning process.
In step S200, the relay learning unit 120 registers the first relay entry 211 in the first relay table 210 based on the information obtained in step S120.
Further, the relay learning unit 120 registers the second relay entry 221 in the second relay table 220 based on the information obtained in step S120.
Details of the relay learning process (S200) will be described later.

Step S300 is a relay determination process.
In step S300, the relay determination unit 130 selects a transmission port based on the information obtained in step S120 and the first relay table 210 and the second relay table 220.
The transmission port is a communication port 904 that outputs the received frame 200.
Details of the relay determination process (S300) will be described later.

Step S130 is a transmission process.
In step S130, the transmission unit 193 corresponding to each transmission port transmits the received frame 200 from the transmission port.
As a result, the received frame 200 is relayed from the network 910 connected to the reception port to the network 910 connected to the transmission port.
However, if no transmission port is selected in step S300, step S130 is not executed.

Based on FIG. 8, the procedure of the relay learning process (S200) will be described.
In step S210, the relay learning unit 120 generates the first relay entry 211 by associating the same destination address as the transmission source address 201 with the same destination port as the reception port.
Then, the relay learning unit 120 registers the generated first relay entry 211 in the first relay table 210.

In steps S221 and S222, the relay learning unit 120 determines whether the message correspondence table 230 includes the first message type that is the same as the analysis message type. Specifically, the relay learning unit 120 operates as follows.

In step S221, the relay learning unit 120 searches the message correspondence table 230 for a message correspondence entry 231 including the same first message type as the analysis message type.
In FIG. 8, the message corresponding entry 231 including the same first message type as the analysis message type is referred to as a corresponding entry.

In step S222, the relay learning unit 120 determines whether there is a corresponding entry based on the search result.
If there is a corresponding entry, the process proceeds to step S223.
If there is no corresponding entry, the second relay entry 221 is not registered and the process ends.

In step S223, the relay learning unit 120 acquires a second message type corresponding to the same first message type as the analysis message type from the message correspondence table 230.
Specifically, the relay learning unit 120 acquires the second message type from the corresponding entry.

In step S230, the relay learning unit 120 associates the same source address as the destination address 202, the same relay message type as the second message type acquired in step S223, and the same destination port as the reception port, A second relay entry 221 is generated.
Then, the relay learning unit 120 registers the generated second relay entry 221 in the second relay table 220.

Based on FIG. 9, the procedure of the relay determination process (S300) will be described.
In steps S <b> 311 to S <b> 313, the relay determination unit 130 selects a destination port corresponding to the destination address 202 from the first relay table 210. Specifically, the relay determination unit 130 operates as follows.

In step S <b> 311, the relay determination unit 130 searches the first relay table 210 for the first relay entry 211 including the destination address 202.
In FIG. 9, the first relay entry 211 including the destination address 202 is referred to as a first corresponding entry.

In step S312, the relay determination unit 130 determines whether there is a first corresponding entry based on the search result.
If there is a first corresponding entry, the process proceeds to step S313.
If there is no first corresponding entry, the process proceeds to step S340.

In step S313, the relay determination unit 130 acquires a destination port identifier from the first corresponding entry.

From step S321 to step S323, the relay determination unit 130 selects a destination port corresponding to a combination of the source address 201 and the same relay message type as the analysis message type from the second relay table 220. Specifically, the relay determination unit 130 operates as follows.

In step S321, the relay determination unit 130 searches the second relay table 220 for the second relay entry 221 including the transmission source address 201 and the same relay message type as the analysis message type.
In FIG. 9, the second relay entry 221 including the source address 201 and the same relay message type as the analysis message type is referred to as a second corresponding entry. The second corresponding entry is one or more second relay entries 221.

In step S322, the relay determination unit 130 determines whether there is a second corresponding entry based on the search result.
If there is a second corresponding entry, the process proceeds to step S323.
If there is no second corresponding entry, the process proceeds to step S330.

In step S323, the relay determination unit 130 acquires a destination port identifier from each second corresponding entry.

In step S330, the relay determination unit 130 excludes the same destination port as the reception port from the destination port selected in steps S311 to S313 and the destination port selected in steps S321 to S323.
As a result, the remaining destination port is selected as the transmission port.

Specifically, the relay determination unit 130 deletes the reception port identifier from the destination port identifier acquired in step S313 and the destination port identifier acquired in step S323.

In step S340, the relay determination unit 130 excludes the reception port from all the communication ports 904.
As a result, the remaining communication ports 904 excluding the reception ports from all the communication ports 904 are selected as transmission ports.

Based on FIG. 10, the relay learning process (S200) and the relay determination process (S300) will be specifically described.
In the bus network, the relay device 100 is connected to the network 910-1 and the network 910-2.
Port 1 is a communication port 904-1, and port 2 is a communication port 904-2.
Terminal B101 is a terminal connected to network 910-1. The address of terminal B101 is address B.
Terminal C102 and terminal D103 are terminals connected to network 910-2. The address of terminal C102 is address C, and the address of terminal D103 is address D.

First, the relay learning process (S200) will be described for the case where the terminal C102 transmits an X request frame to the terminal D103.
The X request frame is a frame 200 including an X request message.
The X request frame propagates through the network 910-2, arrives at the port 2, and is received by the receiving unit 192-2.
When the X request frame is received, the frame analysis unit 110 obtains a transmission source address C, a destination address D, an “X request message”, and “port 2”. “X request message” is the type of the X request message, and “port 2” is the identifier of the reception port 2.

The relay learning unit 120 uses the source address C and “port 2” to register the first relay entry 211-1 in the first relay table 210 as shown in FIG. 11 (S210 in FIG. 8).
In the first relay entry 211-1, the destination address is the source address C, and the destination port identifier is “port 2”.

The relay learning unit 120 selects the message correspondence entry 231-1 including the same first message type as the “X request message” from the message correspondence table 230 in FIG. 5 (S221 and S222 in FIG. 8).
The relay learning unit 120 acquires the “X response message” that is the second message type from the selected message corresponding entry 231-1 (S223 in FIG. 8).
The relay learning unit 120 registers the second relay entry 221-1 in the second relay table 220 as shown in FIG. 12 using the destination address D, “X response message”, and “port 2” (FIG. 8). S230).
In the second relay entry 221-1, the source address is the destination address D, the relay message type is “X response message”, and the destination port is “port 2”.

Next, the relay learning process (S200) will be described for the case where the terminal D103 transmits an X response frame to the terminal C102.
The X response frame is a frame 200 including an X response message.
In the X response frame, the source address 201 is the address D and the destination address 202 is the address C.
The X response frame propagates through the network 910-2, arrives at the port 2, and is received by the receiving unit 192-2.
When the X response frame is received, the frame analysis unit 110 obtains a transmission source address D, a destination address C, an “X response message”, and “port 2”. “X response message” is the type of the X response message.

The relay learning unit 120 registers the first relay entry 211-2 in the first relay table 210 as shown in FIG. 13 using the transmission source address D and “port 2” (S210 in FIG. 8).
In the first relay entry 211-2, the destination address is the transmission source address D, and the destination port identifier is “Port 2”.

The relay learning unit 120 searches the message correspondence table 230 of FIG. 5 for a message correspondence entry 231 including the same first message type as the “X response message” (S221 of FIG. 8). However, since the corresponding message corresponding entry 231 does not exist, the relay learning unit 120 does not register the second relay entry 221 (S222 in FIG. 8).

Next, the relay determination process (S300) will be described for the case where the terminal C102 newly transmits an X request frame to the terminal D103. The first relay table 210 is in the state of FIG. 13, and the second relay table 220 is in the state of FIG.

The relay determination unit 130 selects the first relay entry 211-2 including the destination address D from the first relay table 210 in FIG. 13 (S311 and S312 in FIG. 9).
The relay determination unit 130 acquires “port 2” as the destination port identifier from the selected first relay entry 211-2 (S313 in FIG. 9).

The relay determination unit 130 searches the second relay table 220 in FIG. 12 for the second relay entry 221 corresponding to the combination of the source address C and the “X request message” (S321 in FIG. 9). However, the corresponding second relay entry 221 does not exist (S322 in FIG. 9).

The relay determination unit 130 deletes “port 2” that is the identifier of the reception port 2 from “port 2” that is the acquired destination port identifier (S330 in FIG. 9).
As a result, since there is no acquired destination port identifier, no transmission port is selected, and the X request frame is not relayed.

Next, the relay determination process (S300) will be described for the case where the terminal D103 newly transmits an X response frame to the terminal C102. The first relay table 210 is in the state of FIG. 13, and the second relay table 220 is in the state of FIG.

The relay determination unit 130 selects the first relay entry 211-1 including the destination address C from the first relay table 210 in FIG. 13 (S311 and S312 in FIG. 9).
The relay determination unit 130 acquires “port 2” as the destination port identifier from the selected first relay entry 211-1 (S313 in FIG. 9).

The relay determination unit 130 selects the second relay entry 221-1 corresponding to the combination of the source address D and the “X response message” from the second relay table 220 in FIG. 12 (S321 and S322 in FIG. 12). .
The relay determination unit 130 acquires “port 2” that is a destination port identifier from the selected second relay entry 221-1 (S323 in FIG. 9).

The relay determination unit 130 deletes “port 2” that is the identifier of the reception port 2 from “port 2” that is the acquired destination port identifier.
As a result, since there is no acquired destination port identifier, no transmission port is selected, and the X response frame is not relayed.

As described above, the frame 200 communicated between the terminal C102 and the terminal D103 in the network 910-2 is not relayed to the network 910-1. Therefore, it is possible to suppress the bandwidth consumption of the network 910-1.

The relay learning process (S200) will be specifically described based on FIG. The configuration of the bus network is the same as in FIG. The first relay table 210 is in the state of FIG. 13, and the second relay table 220 is in the state of FIG.
Terminal B101 transmits an X request frame to terminal D103.
The X request frame propagates through the network 910-1 and arrives at the port 1 and is received by the receiving unit 192-1.
When the X request frame is received, the frame analysis unit 110 obtains a source address B, a destination address D, an “X request message”, and “port 1”. “Port 1” is an identifier of the reception port 1.

The relay learning unit 120 registers the first relay entry 211-3 in the first relay table 210 as shown in FIG. 3 using the source address B and “port 1” (S210 in FIG. 8).
In the first relay entry 211-3, the destination address is the source address B, and the destination port is “port 1”.

The relay learning unit 120 selects the message correspondence entry 231-1 including the same first message type as the “X request message” from the message correspondence table 230 in FIG. 5 (S221 and S222 in FIG. 8).
The relay learning unit 120 acquires the “X response message” that is the second message type from the selected message corresponding entry 231-1 (S223 in FIG. 8).
The relay learning unit 120 registers the second relay entry 221-2 in the second relay table 220 as shown in FIG. 4 using the destination address D, “X response message”, and “port 1” (FIG. 8). S230).
In the second relay entry 221-2, the source address is the destination address D, the relay message type is “X response message”, and the destination port is “port 1”.

Note that the relay device 100 relays the X request frame from the port 2 to the network 910-2 by a normal relay function. The X request frame is received by the terminal D103.
Thereafter, the terminal D103 transmits an X response frame to the terminal B101, and the X response frame arrives at the port 2 from the network 910-2. Then, the relay device 100 relays the X response frame to the network 910-1 by a normal relay function. Then, the X response frame is received by the terminal B101.

The relay determination process (S300) will be specifically described based on FIG. The configuration of the bus network is the same as in FIG. The first relay table 210 is in the state of FIG. 3, and the second relay table 220 is in the state of FIG.

First, a case where terminal C102 transmits an X request frame to terminal D103 will be described.
The relay determination unit 130 selects the first relay entry 211-2 including the destination address D from the first relay table 210 in FIG. 3 (S311 and S312 in FIG. 9).
The relay determination unit 130 acquires “port 2” as the destination port identifier from the selected first relay entry 211-2 (S313 in FIG. 9).

The relay determination unit 130 searches the second relay table 220 in FIG. 4 for the second relay entry 221 corresponding to the combination of the source address C and the “X request message” (S321 in FIG. 9). However, the corresponding second relay entry 221 does not exist (S322 in FIG. 9).

The relay determination unit 130 deletes “port 2” that is the identifier of the reception port 2 from “port 2” that is the acquired destination port identifier.
As a result, since there is no acquired destination port identifier, no transmission port is selected, and the X request frame is not relayed.

Next, a case where the terminal D103 transmits an X response frame to the terminal C102 will be described.
The relay determination unit 130 selects the first relay entry 211-1 including the destination address C from the first relay table 210 in FIG. 3 (S311 and S312 in FIG. 9).
The relay determination unit 130 acquires “port 2” as the destination port identifier from the selected first relay entry 211-1 (S313 in FIG. 9).

The relay determination unit 130 selects the second relay entry 221-1 and the second relay entry 221-2 corresponding to the set of the transmission source address D and the “X response message” from the second relay table 220 of FIG. (S321, S322 in FIG. 9).
The relay determination unit 130 acquires “port 2” that is the destination port identifier from the selected second relay entry 221-1, and “port that is the destination port identifier from the selected second relay entry 221-2. 1 ”is acquired.

The relay determination unit 130 deletes “port 2” that is the identifier of the reception port 2 from “port 1” and “port 2” that are the acquired destination port identifiers.
As a result, since “port 1” remains from the acquired destination port identifier, port 1 is selected as the transmission port. Then, the X response frame is relayed to the network 910-1 by the transmission unit 193-1 and received by the terminal B101.
The terminal B101 can obtain the X response message from the relayed X response frame by the monitoring function.

As described above, the terminal B 101 can receive the X response frame and obtain the X response message without transmitting the X request frame itself. Therefore, it is possible to suppress the bandwidth consumption of the network 910-1.

*** Effects of Embodiment 1 ***
It is possible to suppress the bandwidth to be used by using both the bridge method and the monitoring method.

For example, the air conditioning system has the following effects.
In FIG. 10, terminal B101 is an air conditioning controller, terminal D103 is a temperature sensor, and terminal C102 is an indoor unit.
The air conditioning controller is a computer that periodically acquires temperature information and controls air conditioning.
In such an air conditioning system, if the indoor unit periodically transmits and receives a request frame and a response frame to the temperature sensor in order to acquire temperature information, the relay device 100 periodically relays the response frame to the air conditioning controller. To do.
For this reason, the air conditioning controller can acquire temperature information from a response frame that is periodically relayed without periodically transmitting the request frame itself.

Also, for request frames that do not need to be received by the air conditioning controller, the relay device 100 does not relay to the air conditioning controller. Therefore, bandwidth consumption of the network 910-1 can be suppressed.

Thus, it becomes possible to use both the bridge method and the monitoring method at the same time, and both band consumption reduction effects can be obtained.

*** Other configurations ***
The number of network interfaces 903 and communication ports 904 may be three or more.

Like the general FDB, the second relay table 220 corresponding to the extended FDB may have an aging function. That is, when the second relay table 220 is not updated for a certain time, the relay learning unit 120 may delete the second relay entry 221.

A part or all of the message correspondence table 230 may be dynamically set from an external server. Further, the relay learning unit 120 may learn the correspondence between messages by monitoring the relay frame, and register the message correspondence entry 231 in the message correspondence table 230.

The address registered in the first relay table 210 and the second relay table 220 may be an address used for frame transmission or a logical address of the terminal. In the case of IP communication using Ethernet (registered trademark) that is generally used as an example, the address registered in the first relay table 210 corresponding to the FDB is the MAC address, and the second relay table 220 corresponding to the extended FDB is stored in the second relay table 220. The registered address may be an IP address. IP is an abbreviation for Internet Protocol, and MAC is an abbreviation for Media Access Control.

Embodiment 2. FIG.
A mode of determining whether or not to relay the frame 200 using the relay message type list will be described mainly based on FIGS. 16 to 19 with respect to differences from the first embodiment.

*** Explanation of configuration ***
The configuration of relay device 100 is the same as that of FIG.
However, the relay message list 240 is stored in the storage unit 191.
As shown in FIG. 16, the relay message list 240 is a list including relay message types. The relay message list 240 is generated in advance.
A method of using the relay message list 240 will be described later.

*** Explanation of operation ***
The procedure of the relay method is the same as that in FIG. 7 of the first embodiment.
However, part of the procedure of the relay determination process (S300) is different from the first embodiment.

Based on FIG. 17, the procedure of relay determination processing (S300) will be described.
Steps S311 to S340 are the same as those in FIG. 9 of the first embodiment.
Steps S351 and S352 are added processes. Below, step S351 and step S352 are demonstrated.

In step S351, the relay determination unit 130 searches the relay message list 240 for the same relay message type as the analysis message type.

In step S352, the relay determination unit 130 determines whether the relay message list 240 includes the same relay message type as the analysis message type based on the search result.
If the relay message list 240 includes the same relay message type as the analysis message type, the process proceeds to step S340.
If the same relay message type as the analysis message type is not included in the relay message list 240, the process proceeds to step S321.

Therefore, when the relay message list 240 includes the same relay message type as the analysis message type, the remaining communication ports 904 excluding the reception ports from all the communication ports 904 are selected as transmission ports.
When the same relay message type as the analysis message type is not included in the relay message list 240, the reception port is excluded from the destination ports selected from the first relay table 210 and the second relay table 220 as in the first embodiment. The remaining destination ports are selected as transmission ports.

The relay determination process (S300) will be specifically described based on FIG.
The first relay table 210 is in the state shown in FIG.

First, a case where terminal C102 transmits an X request frame to terminal D103 will be described.
The relay determination unit 130 searches the first relay table 210 of FIG. 11 for the first relay entry 211-2 including the destination address D (S311 of FIG. 17). However, the corresponding first relay entry 211 does not exist (S312 in FIG. 17).

The relay determination unit 130 excludes the reception port 2 from all the communication ports 904 (S340 in FIG. 17).
As a result, port 1 is selected as the transmission port. Then, the X request frame is relayed to the network 910-1 by the transmission unit 193-1.

Next, a case where the terminal D103 transmits an X response frame to the terminal C102 will be described.
The relay determination unit 130 selects the first relay entry 211-1 including the destination address C from the first relay table 210 in FIG. 11 (S311 and S312 in FIG. 17).
The relay determination unit 130 acquires “port 2” as the destination port identifier from the selected first relay entry 211-1 (S313 in FIG. 17).

The relay determination unit 130 searches for the “X response message” from the relay message list 240 in FIG. 16 (S351 in FIG. 17). The relay message list 240 in FIG. 16 includes “X response message” (S352 in FIG. 17).

The relay determination unit 130 excludes the reception port 2 from all the communication ports 904 (S340 in FIG. 17).
As a result, port 1 is selected as the transmission port. Then, the X response frame is relayed to the network 910-1 by the transmission unit 193-1 and received by the terminal B101.
The terminal B101 can obtain the X response message from the relayed X response frame by the monitoring function.

*** Effects of Embodiment 2 ***
By registering messages that are highly likely to be referenced in the relay message list 240, it is possible to suppress the transmission of periodic request messages and to reduce the bandwidth consumption of the network 910.

The second relay table 220 may not be used.
Specifically, steps S221 to S230 in FIG. 8 and steps S321 to S323 in FIG. 9 may be omitted.
As a result, the processing load on the relay device 100 can be reduced.

*** Other configurations ***
Instead of the relay message list 240, the relay message table 250 may be used.

Based on FIG. 18, the structure of the relay message table 250 will be described.
The relay message table 250 has entries corresponding to records.
The entry included in the relay message table 250 is referred to as a relay message entry (251-1, 251-2). The relay message entries (251-1, 251-2) are collectively referred to as a relay message entry 251.
In the relay message entry 251, the relay message identifier and the destination port are associated with each other. A destination port identifier is set in the destination port field.
The relay message table 250 is generated in advance.

Based on FIG. 19, the relay determination process (S300) when the relay message table 250 is used will be described.
Steps S311 to S340 are the same as those in FIG. 9 of the first embodiment.
Steps S361 to S363 are added processes. Hereinafter, steps S361 to S363 will be described.

In steps S361 to S363, the relay determination unit 130 selects a destination port corresponding to the analysis message type from the relay message table 250. Specifically, the relay determination unit 130 operates as follows.

In step S361, the relay determination unit 130 searches the relay message table 250 for a relay message entry 251 including the same relay message type as the analysis message type.
In FIG. 19, the relay message entry 251 including the same relay message type as the analysis message type is referred to as a third corresponding entry.

In step S362, the relay determination unit 130 determines whether there is a third corresponding entry based on the search result.
If there is a third corresponding entry, the process proceeds to step S363.
If there is no third corresponding entry, the process proceeds to step S321.

In step S363, the relay determination unit 130 acquires a destination port identifier from the third corresponding entry.
After step S363, the process proceeds to step S330.

In step S330 after step S363, the relay determination unit 130 excludes the same destination port as the reception port from the destination ports selected in steps S361 to S363.
As a result, the remaining destination port is selected as the transmission port.

Embodiment 3 FIG.
With respect to the mode for determining whether or not the frame 200 needs to be relayed based on the transmission band of the communication port 904, differences from the first embodiment will be mainly described with reference to FIGS.

*** Explanation of configuration ***
The configuration of relay device 100 is the same as that of FIG.
Note that the respective transmission bands and reference bands of all the communication ports 904 are stored in the storage unit 191 in advance. The reference band is a reference transmission band. The transmission band of the communication port 904 is the transmission band of the network 910 to which the communication port 904 is connected. The transmission band corresponds to the transmission speed.

*** Explanation of operation ***
The procedure of the relay method is the same as that in FIG. 7 of the first embodiment.
However, a part of the procedure of the relay learning process (S200) and a part of the procedure of the relay determination process (S300) are different from the first embodiment.

The procedure of the relay learning process (S200) will be described based on FIG.
Step S210 and steps S221 to S230 are the same as those in FIG. 8 of the first embodiment.
Step S220 is a process added to FIG. 8 of the first embodiment. Below, step S220 is demonstrated.

In step S220, the relay determination unit 130 determines the necessity of registration based on the transmission band of the reception port.
Specifically, relay determination unit 130 compares the transmission band of the reception port with the reference band.
If the transmission band of the receiving port is equal to or greater than the reference band (registration is not necessary), the process ends.
If the transmission bandwidth of the reception port is less than the reference bandwidth (registration is required), the process proceeds to step S221.

Therefore, when the transmission band of the reception port is equal to or greater than the reference band, the second relay entry 221 is not registered.

Based on FIG. 21, the procedure of relay determination processing (S300) will be described.
Steps S311 to S330 are the same as those in FIG. 9 of the first embodiment.
Step S310 is an added process. Below, step S310 is demonstrated.

In step S310, the relay determination unit 130 determines the necessity of narrowing down based on the transmission band of the remaining communication ports 904 excluding the reception port.
Specifically, the relay determination unit 130 compares the transmission band of the communication port 904 with the reference band for each communication port 904 except for the reception port.
Then, the relay determination unit 130 determines whether there is a low bandwidth port except for the reception port. The low-band port is a communication port 904 having a transmission band less than the reference band.
If there is a low-band port (needs to be narrowed down), the process proceeds to step S311.
If there is no low-band port (no narrowing is required), the process proceeds to step S340.

Therefore, when there is no low-band port, the remaining communication ports 904 excluding the reception port are selected as transmission ports.

Based on FIG. 22, the relay learning process (S200) and the relay determination process (S300) will be specifically described.
In the bus type network, there are two relay apparatuses (100-1 and 100-2). The relay device 100-1 and the relay device 100-2 are collectively referred to as a relay device 100.

The relay device 100-1 is connected to the network 911 and the network 912. In relay apparatus 100-1, port 1 is connected to network 911, and port 2 is connected to network 912. The transmission band of the network 911 and the port 1 is β bps (bits per second). The transmission band of the network 912 and the port 2 is α bps.

The relay device 100-2 is connected to the network 912 and the network 913. In relay apparatus 100-2, port 1 is connected to network 912, and port 2 is connected to network 913. The transmission band of the network 912 and the port 1 is α bps. The transmission band of the network 913 and the port 2 is β bps.

A terminal A104 is a terminal connected to the network 911. A terminal E105 is a terminal connected to the network 912. A terminal C102 and a terminal D103 are terminals connected to the network 913.
The network 911, the network 912, and the network 913 are collectively referred to as a network 910.

α is sufficiently large with respect to β.
That is, the transmission band α of the network 912 is sufficiently larger than the transmission band β of the network 911 and the network 913.
The reference band is a value not less than β and less than α.

For example, in an air conditioning system and a building system, the transmission band of a network to which a terminal device is connected may be kept low in order to prioritize layability and cost. On the other hand, there are cases where a central network to which a controller for centrally controlling the system or a host system is connected has a sufficient transmission band.

First, the relay learning process (S200) in the relay apparatus 100-2 when the terminal E105 transmits an X request frame to the terminal D103 will be described.
The X request frame propagates through the network 912 and arrives at the port 1 and is received by the receiving unit 192-1. The transmission bandwidth of port 1 is αbps.
When the X request frame is received, the frame analysis unit 110 obtains the transmission source address E, the destination address D, the “X request message”, the “port 1”, and the transmission band α.

The relay learning unit 120 registers the first relay entry 211 including the source address E as the destination address and “port 1” as the destination port identifier in the first relay table 210 (S210 in FIG. 20).

The relay learning unit 120 compares the transmission band α with the reference band (S220 in FIG. 20).
Since the transmission band α is equal to or greater than the reference band, the second relay entry 221 is not registered (S221 to S230 in FIG. 20).

Next, the relay learning process (S200) in the relay apparatus 100-2 when the terminal C102 transmits an X request frame to the terminal D103 will be described.
The X request frame propagates through the network 913 and arrives at the port 2 and is received by the receiving unit 192-2. The transmission bandwidth of port 2 is β bps.
When the X request frame is received, the frame analysis unit 110 obtains the source address C, the destination address D, the “X request message”, the “port 2”, and the transmission band β.

The relay learning unit 120 registers the first relay entry 211 including the transmission source address C as the destination address and “port 2” as the destination port identifier in the first relay table 210 (S210 in FIG. 8).

The relay learning unit 120 compares the transmission band β with the reference band (S220 in FIG. 20).
Since the transmission band β is less than the reference band, the second relay entry 221 is registered (S221 to S230 in FIG. 20).

Next, the relay determination process (S300) in the relay apparatus 100-2 when the terminal C102 transmits an X request frame to the terminal D103 will be described.
The relay determination unit 130 compares the transmission band α of the port 1 with the reference band except for the reception port 2. Since the transmission band α is not less than the reference band, the port 1 is not a low-band port (S310 in FIG. 21).
The relay determination unit 130 excludes the reception port 2 from all the communication ports 904 (S340 in FIG. 21).
As a result, port 1 is selected as the transmission port. Then, the X request frame is relayed to the network 912 by the transmission unit 193-1.

Next, the relay determination process (S300) in the relay apparatus 100-2 when the terminal D103 transmits an X response frame to the terminal C102 will be described.
The X response frame propagates through the network 913 and arrives at the port 2 and is received by the receiving unit 192-2. The transmission bandwidth of port 2 is β bps.
When the X response frame is received, the frame analysis unit 110 obtains a transmission source address D, a destination address C, an “X response message”, “port 2”, and a transmission band β.

The relay determination unit 130 compares the transmission band α of the port 1 with the reference band except for the reception port 2. Since the transmission band α is not less than the reference band, the port 1 is not a low-band port (S310 in FIG. 21).
The relay determination unit 130 excludes the reception port 2 from all the communication ports 904 (S340 in FIG. 21).
As a result, port 1 is selected as the transmission port. Then, the X response frame is relayed to the network 912 by the transmission unit 193-1 and received by the terminal E105.
The terminal E105 can obtain the X response message from the relayed X response frame by the monitoring function.

*** Effects of Embodiment 3 ***
By omitting learning of the second relay table 220 and relay determination using the second relay table 220 for a network with a wide transmission band, it is possible to reduce the processing load of the relay device 100.
Since the frame 200 is not relayed to the network 910 having a narrow transmission band, the band consumption of the network 910 having a narrow transmission band can be suppressed.
In the network 910 having a wide transmission band, it is possible to obtain a band consumption reduction effect by the terminal monitoring method.

*** Other configurations ***
Instead of the transmission band of the reception port, a band difference or a band ratio between the reception port and the transmission port may be compared with the reference band. The band difference is a transmission band difference, and the band ratio is a transmission band ratio.

*** Supplement to the embodiment ***
In the embodiment, the function of the relay device 100 may be realized by hardware.
FIG. 23 shows a configuration when the function of the relay device 100 is realized by hardware.
The relay apparatus 100 includes a processing circuit 990. The processing circuit 990 is also called a processing circuit.
The processing circuit 990 is a dedicated electronic circuit that realizes the functions of “units” such as the frame analysis unit 110, the relay learning unit 120, the relay determination unit 130, and the storage unit 191.
Specifically, the processing circuit 990 is a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, a logic IC, a GA, an ASIC, an FPGA, or a combination thereof. GA is an abbreviation for Gate Array, ASIC is an abbreviation for Application Specific Integrated Circuit, and FPGA is an abbreviation for Field Programmable Gate Array.

The relay apparatus 100 may include a plurality of processing circuits that replace the processing circuit 990. The plurality of processing circuits share the function of “unit”.

The functions of the relay device 100 may be realized by a combination of software and hardware. That is, a part of the function of “unit” may be realized by software, and the rest of the function of “unit” may be realized by hardware.

The embodiment is an example of a preferred embodiment and is not intended to limit the technical scope of the present invention. The embodiment may be implemented partially or in combination with other embodiments. The procedure described using the flowchart and the like may be changed as appropriate.

100 relay device, 101 terminal B, 102 terminal C, 103 terminal D, 104 terminal A, 105 terminal E, 110 frame analysis unit, 120 relay learning unit, 130 relay determination unit, 191 storage unit, 192 reception unit, 193 transmission unit , 200 frame, 201 source address, 202 destination address, 203 type, 204 message, 210 first relay table, 211 first relay entry, 220 second relay table, 221 second relay entry, 230 message correspondence table, 231 message Corresponding entry, 240 relay message list, 250 relay message table, 251 relay message entry, 901 processor, 902 memory, 903 network interface, 904 communication port, 9 0,911,912,913 network, 990 processing circuit.

Claims

Multiple communication ports,
A storage unit that stores a relay table in which a source address, a relay message type, and a destination port are associated with each other;
A frame analysis unit that obtains a message type included in the frame as an analysis message type when a frame including a source address and a message arrives at any of the plurality of communication ports;
Select a destination port corresponding to a combination of a source address included in the frame and the same relay message type as the analysis message type from the relay table, and the same destination as the communication port from which the frame arrived from the selected destination port A relay apparatus comprising: a relay determination unit that selects a remaining destination port excluding a port as a communication port that outputs the frame.
The frame includes a destination address;
The storage unit stores a message correspondence table in which the first message type and the second message type are associated with each other;
It is determined whether the first message type that is the same as the analysis message type is included in the message correspondence table. When the first message type that is the same as the analysis message type is included in the message correspondence table, the first same as the analysis message type The second message type corresponding to the message type is obtained from the message correspondence table, the same source address as the destination address included in the frame, and the same relay message type as the second message type obtained from the message correspondence table The relay apparatus according to claim 1, further comprising: a relay learning unit that associates a communication port with which the frame has arrived with the same destination port and registers the same in the relay table.
The frame includes a destination address;
The storage unit stores the relay table as a second relay table, stores a first relay table in which a destination address and a destination port are associated with each other,
The relay determination unit selects a destination port corresponding to a destination address included in the frame from the first relay table, and selects a destination port selected from the first relay table and a destination selected from the second relay table. The relay device according to claim 1, wherein a remaining destination port excluding a destination port that is the same as a communication port from which the frame has arrived is selected as a communication port that outputs the frame.
The relay according to claim 3, further comprising: a relay learning unit that registers the same destination address as the source address included in the frame and the same destination port as the communication port at which the frame arrives in association with each other in the first relay table. apparatus.
The storage unit stores a relay message list including a relay message type,
The relay determination unit determines whether the same relay message type as the analysis message type is included in the relay message list, and when the same relay message type as the analysis message type is included in the relay message list, the plurality of communication The remaining destination port excluding the communication port from which the frame arrived is selected as a communication port that outputs the frame, and the relay message type is not included in the relay message list if the same relay message type as the analysis message type is not included in the relay message list The relay apparatus according to claim 1, wherein a remaining destination port excluding a destination port that is the same as a communication port from which the frame has arrived is selected as a communication port that outputs the frame from destination ports selected from a table.
The storage unit stores a relay message table in which a relay message type and a destination port are associated with each other,
The relay determination unit determines whether the same relay message type as the analysis message type is included in the relay message table, and when the same relay message type as the analysis message type is included in the relay message table, the relay message table A destination port corresponding to the same relay message type as the analysis message type, and outputting the frame to the remaining destination ports excluding the same destination port as the communication port where the frame arrived from the selected destination port Selected as a port, and when the same relay message type as the analysis message type is not included in the relay message table, remaining from the destination port selected from the relay table except the same destination port as the communication port from which the frame arrived The destination port of the Relay apparatus according to claim 1 which is selected as a communication port for outputting the frame.
The relay learning unit determines whether or not registration is necessary based on a transmission band of a communication port at which the frame has arrived, and when it is determined that registration is necessary, the same source address as the destination address included in the frame And the same relay message type as the second message type acquired from the message correspondence table and the same destination port as the communication port at which the frame arrived are associated with each other and registered in the relay table. Relay device.
The relay determination unit determines whether or not narrowing is necessary based on the transmission bandwidth of the remaining communication ports excluding the communication port where the frame has arrived from the plurality of communication ports. When selecting the remaining destination port except the same destination port as the communication port from which the frame arrived from the destination port selected from the relay table as the communication port that outputs the frame, and determining that the narrowing is unnecessary The relay apparatus according to claim 1, wherein a remaining destination port excluding a communication port at which the frame has arrived from the plurality of communication ports is selected as a communication port that outputs the frame.
The relay determination unit determines whether or not narrowing is necessary based on the transmission bandwidth of the remaining communication ports excluding the communication port where the frame has arrived from the plurality of communication ports. The frame is output from the destination port selected from the first relay table and the destination port selected from the second relay table except for the same destination port as the communication port where the frame arrived. When the communication port is selected and it is determined that narrowing is not necessary, the remaining destination port excluding the communication port from which the frame has arrived is selected as the communication port that outputs the frame. 3. The relay device according to 3.