JP2016220189A - Repeating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a repeating device capable of notifying a source device, which sent a frame, of abnormality if the frame is received abnormally and discarded.SOLUTION: A repeating device, having a plurality of ports, for repeating communication among control devices connected to each of the ports through communication lines includes: determination means S120 for determining whether a received frame, a frame received through the port, is normal or abnormal for each of the plurality of ports; discard means S130 for discarding an abnormal frame which is a received frame determined as abnormal by the determination means; and abnormality notification means S150 for transmitting an abnormality notification frame, for notifying a source control device which sent the abnormal frame of occurrence of frame abnormality if a received frame is determined as abnormal by the determination means.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a relay device.

  For example, in an Ethernet (registered trademark) communication system mounted on a vehicle, an Ethernet switch used as a relay device has a function of detecting that a received frame is abnormal and discarding the abnormal frame. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 9-181771

  In the conventional Ethernet switch, when an abnormal frame is discarded, the transmission source device of the frame cannot recognize that the frame has been discarded. For this reason, it is not possible to perform a procedure such as retransmission of a frame.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a relay device that can notify a transmission source device of a frame when the received abnormal frame is discarded.

  The relay device of the first invention has a plurality of ports and relays communication between control devices connected to each port via a communication line. The relay device includes a determination unit, a discard unit, and an abnormality notification unit.

  The determination unit determines, for each of the plurality of ports, whether a received frame that is a frame received from the port is normal or abnormal. The discarding unit discards an abnormal frame that is a received frame determined to be abnormal by the determining unit. For this reason, the abnormal frame is prevented from being relayed to any control device.

  Then, when the determination unit determines that the received frame is abnormal by the determination unit, the abnormality notification unit notifies the transmission source device that is the transmission source control device of the abnormal frame that is determined to be abnormal. An abnormality notification frame for notification is transmitted.

  Therefore, the transmission source device can know from the abnormality notification frame from the relay device that the transmitted frame has become abnormal. For this reason, the transmission source device can perform a procedure such as retransmission of a frame.

  In addition, the code | symbol in the parenthesis described in the claim shows the correspondence with the specific means as described in embodiment mentioned later as one aspect, Comprising: The technical scope of this invention is limited is not.

It is a block diagram showing the structure of the communication system of embodiment. It is explanatory drawing which shows the structure of an Ethernet frame. It is a flowchart showing the abnormality handling process of 1st Embodiment. It is a flowchart showing the abnormality handling process of 2nd Embodiment. It is a flowchart showing the abnormality handling process of 3rd Embodiment. It is a flowchart showing the relay impossible notification process of 4th Embodiment.

Embodiments to which the present invention is applied will be described below.
[First Embodiment]
<Constitution>
A communication system 1 of the embodiment shown in FIG. 1 is an Ethernet network communication system mounted on a vehicle such as a passenger car, and includes an Ethernet switch 10 and a plurality of (three in this example) control devices ECUs 11 to 13. Is provided. ECU is an abbreviation for “Electronic Control Unit”.

  The Ethernet switch 10 includes a plurality (three in this example) of ports 21 to 23 and a control unit 25. The control unit 25 includes an abnormality detection unit 26 and an abnormality management unit 27.

  Communication ports 31 to 33 are respectively connected to the ports 21 to 23 of the Ethernet switch 10, and ECUs 11 to 13 as communication nodes are respectively connected to the communication lines 31 to 33. The Ethernet switch 10 relays communication between the ECUs 11 to 13 in accordance with the Ethernet standard. The relay process is performed by the control unit 25. The control unit 25 is configured by, for example, an IC (integrated circuit) combined with logic circuits or a microcomputer.

Therefore, the ECUs 11 to 13 are communicably connected via the communication lines 31 to 33 and the Ethernet switch 10 and communicate with each other according to the Ethernet standard.
A frame communicated between the ECUs 11 to 13 (in other words, a communication frame relayed by the Ethernet switch 10) is an Ethernet frame with a VLAN (Virtual Local Area Network) tag, for example, as shown in FIG. The Ethernet frame includes areas of a preamble, a destination MAC address, a transmission source MAC address, a VLAN tag, a type, data, and FCS (Frame Check Sequence).

<processing>
The abnormality handling process performed by the control unit 25 of the Ethernet switch 10 will be described with reference to FIG. The abnormality handling process of FIG. 3 is a process executed for each of the ports 21 to 23, and is started when a frame transmitted from any of the ECUs 11 to 13 is input to the target port.

  In the following description, the port targeted for the abnormality handling process is referred to as a target port. Hereinafter, a frame received from the ports 21 to 23 in the Ethernet switch 10 is referred to as a received frame. 3 are classified into the processes in steps S120 and S130 by the abnormality detection unit 26 of the control unit 25, and the processes in and after S140 are performed by the abnormality management unit 27 of the control unit 25. This is a process to be performed.

  As illustrated in FIG. 3, in the abnormality handling process, the control unit 25 performs a process of receiving a frame input to the target port (that is, a frame transmitted from an ECU connected to the target port) in S110. .

  In step S120, the control unit 25 determines whether the frame (reception frame) received in step S110 is normal or abnormal. Specifically, the control unit 25 detects that the received frame is abnormal when, for example, an FCS error is detected for the received frame, or when the number of bits in each area (see FIG. 2) in the received frame is not a normal value. Judge that there is. The FCS error is a data error in the received frame that is detected using error detection data in the FCS area.

  That is, the control unit 25 performs bit number determination for determining whether or not the number of bits of the received frame is a normal value, and error detection for detecting a data error of the received frame using the error detection data included in the received frame. At least do. Then, when the number of bits of the received frame is determined to be not normal by the number of bits determination, or when a data error of the received frame is detected by error detection, the received frame is determined to be abnormal. Further, when the number of bits of the received frame is determined to be a normal value by the number of bits determination, and the data error of the received frame is not detected by the error detection, it is determined that the received frame is normal.

  The processing for determining the number of bits may be processing for determining whether or not the number of bits is normal for each area of the received frame, or whether or not the number of bits is normal for a specific area of the received frame. Or a process of determining whether the number of bits is a normal value for the entire received frame. The target of the bit number determination may be either the whole received frame or a part thereof.

Further, the error detection process is specifically as follows.
First, the ECU on the frame transmission side performs a predetermined algorithm calculation on a specific portion of the frame to be transmitted, and places the calculation result as error detection data in the FCS area of the frame. In the present embodiment, the specific part to be calculated is a part from the destination MAC address to the data.

  For this reason, the control unit 25 performs the same algorithm operation as that of the transmission side on the portion from the destination MAC address to the data in the received frame, and calculates the calculation result and the error detection data in the FCS area in the received frame. Compare. If the calculation result and the error detection data match, it is determined that there is no data error in the received frame. If the calculation result and the error detection data do not match, there is a data error in the reception frame. Is determined. In this embodiment, CRC is used as an arithmetic algorithm for error detection data, but other algorithms may be used. CRC is an abbreviation for “Cyclic Redundancy Check”, that is, cyclic redundancy code.

  When it is determined that the received frame is normal (S120: NO), the control unit 25 ends the abnormality handling process as it is. In this case, the control unit 25 performs a process of relaying the received frame. For example, a non-volatile memory (not shown) included in the control unit 25 stores a relay table indicating from which port a frame of which destination MAC address is transmitted, and the control unit 25 stores the relay table. Based on the above, the received frame is relayed. For example, when the destination MAC address of the frame received from the port 21 indicates the ECU 13, the frame is transmitted from the port 23.

  On the other hand, when it is determined that the received frame is abnormal (S120: YES), the control unit 25 proceeds to S130 and discards the received frame. Specifically, the control unit 25 deletes the received frame from the volatile memory in which the received frame is stored.

  When the received frame is discarded in S130, the control unit 25 notifies the abnormality management unit 27 from the abnormality detection unit 26 that the reception frame is abnormal. And the control part 25 will perform the process after S140 by the abnormality management part 27. FIG.

In S140, the control unit 25 generates an abnormality notification frame.
The abnormality notification frame is a frame for notifying that an abnormality of the frame has occurred to an ECU (hereinafter referred to as a transmission source ECU) that is a transmission source of a received frame (hereinafter also referred to as an abnormal frame) determined to be abnormal. is there. The transmission source ECU corresponds to a transmission source device.

An identification code indicating that this frame is an abnormality notification frame is arranged at a specific position in the VLAN tag region, for example, in each region of the abnormality notification frame.
Further, a MAC address indicating the transmission source ECU is arranged in the destination MAC address area of the abnormality notification frame. For example, if the target port is port 21, since the transmission source ECU is ECU 11, the MAC address indicating ECU 11 is placed in the destination MAC address area of the abnormality notification frame.

  The data area of the received frame is copied and arranged in the data area of the abnormality notification frame. For this reason, the transmission source ECU that has received the abnormality notification frame identifies to which frame the abnormality notification frame is transmitted from the ECU by the data in the data area of the abnormality notification frame. Can do. That is, the transmission source ECU can determine which frame is abnormal. The data arranged in the data area of the abnormality notification frame is “information that can identify to which frame the abnormality notification frame is transmitted from the transmission source ECU (hereinafter referred to as abnormal frame information). Is equivalent to.

  As another example, for example, it is assumed that the ECUs 11 to 13 arrange the sequence number of the frame in the VLAN tag area of the frame to be transmitted. In this case, the control unit 25 may arrange the sequence number arranged in the VLAN tag area of the received frame in the VLAN tag area of the abnormality notification frame. Even in this way, the transmission source ECU can identify to which frame the abnormality notification frame is transmitted from the ECU by the sequence number in the abnormality notification frame. In this case, the sequence number in the abnormality notification frame corresponds to the abnormal frame information described above.

  The sequence number may be arranged at a specific position in the data area of the frame, for example. The abnormal frame information included in the abnormality notification frame may be both the sequence number in the received frame and the data in the data area. In this case, even if one of the sequence number and the data in the data area in the received frame is destroyed, the other is correct. Therefore, the transmission source ECU can more correctly determine which frame has become abnormal based on at least one of the sequence number and the data in the data area in the abnormality notification frame.

  When the control unit 25 generates the abnormality notification frame, in S150, the control unit 25 transmits the generated abnormality notification frame from the target port (that is, the port that received the abnormality frame). Then, the transmitted abnormality notification frame is received by the transmission source ECU.

  In step S160, the control unit 25 counts up the abnormal count value. Specifically, the abnormal count value is increased by one. The abnormality count value is a value of an abnormality counter for counting the number of times that the received frame is determined to be abnormal in S120. The initial value of the abnormal count value is zero.

  In the next S170, the control unit 25 determines whether or not the abnormality count value is equal to or greater than a predetermined threshold value N1 (for example, 20). If the abnormal count value is equal to or greater than the threshold value N1, the process proceeds to S180.

In S180, the control unit 25 performs a port disconnection process for disconnecting the target port, and then ends the abnormality handling process.
Disconnecting the target port means that the target port is excluded from the communication relay target, and more specifically, the frame is not relayed between the target port and another port. . For this reason, when the target port is disconnected, a frame input to the target port is not output from another port, and a frame input from another port is not output from the target port.

  For example, as the port disconnection process, the control unit 25 performs a process of prohibiting the relay of a frame between the target port and another port. Further, for example, the port disconnection process may be a process of stopping the operation of the transceiver of the target port (that is, a transmission / reception circuit for inputting / outputting a communication signal). As a process for stopping the operation of the transceiver, for example, a process for shutting off the power to the transceiver can be considered.

<Examples of abnormal response processing>
For example, as indicated by an arrow Y1 in FIG. 1, it is assumed that a frame destined for the ECU 12 or the ECU 13 is transmitted from the ECU 11 and the frame is destroyed due to an abnormality or noise of the communication line 31.

  In that case, in the Ethernet switch 10, the abnormality detection unit 26 of the control unit 25 determines that the received frame from the port 21 is abnormal, discards the received frame, and sends the received frame to the abnormality management unit 27. Notify that there was an abnormality. Then, the abnormality management unit 27 of the control unit 25 transmits an abnormality notification frame to the ECU 11 that is a transmission source of the frame determined to be abnormal, as indicated by an arrow Y2 in FIG.

  In the Ethernet switch 10, the abnormality management unit 27 disconnects the port 21 when the number of times that the received frame from the port 21 is determined to be abnormal is equal to or greater than the threshold N1, for example.

<effect>
When the received frame determined to be abnormal is discarded, the control unit 25 of the Ethernet switch 10 transmits an abnormality notification frame to the transmission source ECU that is the transmission source of the abnormal reception frame. Therefore, the transmission source ECU can know from the abnormality notification frame from the Ethernet switch 10 that the transmitted frame has become abnormal. For this reason, the transmission source ECU can perform measures such as retransmission of the frame.

  Further, when receiving the abnormality notification frame, the transmission source ECU can determine that the frame transmitted immediately before has become abnormal, but the abnormality notification frame includes the above-described abnormality frame information. Therefore, the transmission source ECU can more correctly determine which frame is abnormal based on the abnormal frame information in the abnormality notification frame. For this reason, for example, the transmission source ECU can more correctly select a frame to be retransmitted.

  Further, the control unit 25 of the Ethernet switch 10 counts the number of times the received frame becomes abnormal for each of the ports 21 to 23 as an abnormal count value (S160). And the control part 25 cut | disconnects the port from which the abnormal count value became more than threshold value N1 among the ports 21-23 (S170: YES, S180).

  For this reason, among the ports 21 to 23, it is possible to improve the reliability of communication by excluding the port considered to be unstable in the signal transmission path including the communication line from the relay target. This is because it is possible to reliably prevent relaying a frame having a possibility of abnormality.

  Further, for example, if the control unit 25 is configured to perform a process for stopping the operation of the port transceiver as the port disconnection process for disconnecting the port, the power consumption in the Ethernet switch 10 can be suppressed. This is advantageous.

  In the first embodiment, among the steps in FIG. 3, S120 corresponds to an example of a determination unit, S130 corresponds to an example of a discarding unit, and S150 corresponds to an example of an abnormality notification unit. Further, S160 corresponds to an example of an abnormality count unit, and S170 and S180 correspond to an example of a port disconnection unit.

[Second Embodiment]
Next, a communication system according to the second embodiment will be described. As a reference numeral of the communication system, “1” that is the same as that of the first embodiment is used. The same reference numerals as those in the first embodiment are used for the same components and processes as those in the first embodiment. This also applies to other embodiments described later.

  The communication system 1 according to the second embodiment is different from the first embodiment in that the control unit 25 of the Ethernet switch 10 performs the abnormality handling process of FIG. 4 instead of the abnormality handling process of FIG. The abnormality handling process of FIG. 4 differs from the abnormality handling process of FIG. 3 in that S165 is added.

  As shown in FIG. 4, when the control unit 25 determines that the received frame is normal (S120: NO), the control unit 25 proceeds to S165, clears the abnormality count value to 0, and ends the abnormality handling process. To do.

For this reason, the abnormal count value counted up in S160 is a value obtained by counting the number of consecutive times that the received frame is determined to be abnormal in S120.
That is, the control unit 25 in the Ethernet switch 10 according to the second embodiment counts the number of consecutive reception frame abnormalities for each of the ports 21 to 23 as an abnormal count value (S160, S165). And the control part 25 cut | disconnects the port from which the abnormal count value became more than threshold value N1 among the ports 21-23 (S170: YES, S180).

  According to the Ethernet switch 10 of the second embodiment, the same effects as those of the first embodiment can be obtained, and the ports 21 to 23 that are considered to have unstable signal transmission paths are excluded from the relay targets. can do.

In the second embodiment, among the steps in FIG. 4, S160 and S165 correspond to an example of a continuous abnormality counting unit, and S170 and S180 correspond to an example of a port disconnecting unit.
[Third Embodiment]
The communication system 1 according to the third embodiment is different from the second embodiment in that the control unit 25 of the Ethernet switch 10 performs the abnormality handling process of FIG. 5 instead of the abnormality handling process of FIG. The abnormality handling process of FIG. 5 differs from the abnormality handling process of FIG. 4 in that S210 to 260 are provided instead of S160 to S180.

As shown in FIG. 5, after transmitting the abnormality notification frame in S150, the control unit 25 proceeds to S210.
In S210, the control unit 25 adds a predetermined weighting coefficient M1 larger than 0 to the count value. The count value corresponds to an evaluation value representing the frequency at which the received frame becomes abnormal. The count value indicates that the larger the value is, the higher the frequency at which the received frame becomes abnormal. The initial value of the count value is 0.

  In the next S220, the control unit 25 determines whether or not the count value is greater than or equal to a predetermined first threshold value Na. If the count value is greater than or equal to the first threshold value Na, the process proceeds to S230, and FIG. As in S180 of No. 4, port disconnection processing for disconnecting the target port is performed. Then, the process proceeds to S240.

  The first threshold value Na is a value larger than the weighting coefficient M1, and is set to a predetermined number of times (for example, 20 times) the weighting coefficient M1. In the third embodiment, even after the target port is disconnected, the reception of the frame from the target port is performed. When the number of normal received frames increases, the target port is disconnected. For this reason, the port disconnection process in S230 is not a process of stopping the operation of the transceiver of the target port, but a process of prohibiting frame relay between the target port and another port.

On the other hand, if the control unit 25 determines in S220 that the count value is not equal to or greater than the first threshold value Na, the control unit 25 proceeds to S240 as it is.
If the control unit 25 determines in S120 that the received frame is normal, the control unit 25 proceeds to S215 and subtracts a predetermined weighting coefficient M2 greater than 0 from the count value. Then, the process proceeds to S240.

  In S240, the control unit 25 determines whether or not the target port is being disconnected (that is, the target port is being disconnected). If the target port is not being disconnected, the abnormality handling process is performed as it is. If the target port is being disconnected, the process proceeds to S250.

In S250, the control unit 25 determines whether or not the count value is equal to or smaller than a second threshold value Nb that is smaller than the first threshold value Na. The second threshold value Nb corresponds to a return threshold value.
When it is determined that the count value is not equal to or less than the second threshold value Nb (S250: NO), the control unit 25 ends the abnormality handling process as it is, but determines that the count value is equal to or less than the second threshold value Nb. In the case (S250: YES), the process proceeds to S260.

  In step S260, the control unit 25 performs port return processing for releasing the target port from being disconnected. That is, the target port is returned to the communication relay target. Specifically, the control unit 25 performs a process of canceling the relay prohibition performed in S230 as the port return process. Then, the control unit 25 ends the abnormality handling process.

  The received frame is abnormal from the number of times of abnormal reception that is the number of times the received frame is determined to be abnormal in S120 and the number of times of normal reception that is the number of times that the received frame is determined to be normal in S120 by S210 and S215 of FIG. The count value indicating the frequency of occurrence is updated.

  Specifically, every time the received frame is determined to be abnormal in S120, the counter value is incremented by the weighting coefficient M1, and conversely, every time the received frame is determined to be normal in S120, the counter value is the weighting coefficient M2. Only reduced. Therefore, a value obtained by subtracting a value obtained by multiplying the number of abnormal receptions by the weighting coefficient M2 as the second coefficient from a value obtained by multiplying the number of abnormal receptions by the weighting coefficient M1 as the first coefficient is calculated as the count value. The Rukoto.

  In the abnormality handling process of FIG. 5, when the count value becomes equal to or greater than the first threshold value Na, the target port is disconnected (S220: YES, S230). After that, when the count value decreases to the second threshold value Nb or less, the target port is disconnected (S250: YES, S260). Such an abnormality handling process is performed for each of the ports 21 to 23.

  According to the Ethernet switch 10 of the third embodiment, the same effects as those of the first and second embodiments can be obtained, and the number of normal receptions can be reduced for the disconnected port (that is, excluded from the relay target). By increasing the number, the disconnection of the port can be released. Therefore, it is possible to appropriately return to the original state in which relaying between all the ports 21 to 23 is performed.

  In addition, from the viewpoint of surely preventing a frame with a possibility of abnormality from being relayed, the condition for releasing the port disconnection should be stricter than the condition for disconnecting the port. It is preferable. For this reason, it is preferable to set the weighting coefficient M2 as the second coefficient to a value smaller than the weighting coefficient M1 as the first coefficient.

  In the third embodiment, among the steps in FIG. 5, S210 and S215 correspond to an example of a calculation means, S220 and S230 correspond to an example of a port disconnection means, and S250 and S260 indicate port return means. It corresponds to an example.

<Modification 1 of 3rd Embodiment>
As a modification, the abnormality handling process in FIG. 5 may be modified as in the following << 1 >> to << 3 >>, for example.

<< 1 >> In S210, the abnormal count value for counting the number of abnormal receptions is counted up.
<< 2 >> In S215, the normal count value for counting the number of normal receptions is counted up.

  << 3 >> An additional step is provided between S210 and S220. In the additional step, the value of “(abnormal count value × weighting coefficient M1) − (normal count value × weighting coefficient M2)” is set to the count value. Calculate as

And even if it deform | transforms in this way, the same result as the abnormality response process of FIG. 5 is obtained.
<Modification 2 of 3rd Embodiment>
In the abnormality handling process of FIG. 5, S240 to S260 may be deleted. In that case, as the port disconnection processing in S230, processing for stopping the operation of the transceiver of the target port may be performed.

[Fourth Embodiment]
The communication system 1 according to the fourth embodiment is different from the first to third embodiments in that the control unit 25 of the Ethernet switch 10 further executes the relay failure notification process of FIG.

  The relay impossible notification process in FIG. 6 is a process executed for a disconnected port among the ports 21 to 23. The disconnected port is a port disconnected by S180 in FIGS. 3 and 4 or S230 in FIG. 6 is started, for example, at regular time intervals or when a frame is received from a port other than the disconnected port among the ports 21 to 23.

  As shown in FIG. 6, in the relay impossible notification process, the control unit 25 determines whether or not a frame addressed to the disconnected port is received from a port other than the disconnected port in S310. Specifically, the frame addressed to the disconnection port is a frame addressed to the ECU connected to the disconnection port.

  If the control unit 25 determines that the frame addressed to the disconnected port has not been received (S310: NO), the control unit 25 ends the relay impossible notification process as it is, but determines that the frame addressed to the disconnected port has been received. If so (S310: YES), the process proceeds to S320.

In S320, the control unit 25 generates a relay impossible notification frame.
The relay impossible notification frame is a frame for notifying the ECU that has transmitted the frame addressed to the disconnected port (hereinafter referred to as a transmission execution ECU) that the frame cannot be relayed. The transmission execution ECU corresponds to a transmission execution device.

  Then, an identification code indicating that this frame is a relay disabled notification frame is arranged at a specific position in the VLAN tag region, for example, in each region of the relay disabled notification frame.

Further, the MAC address indicating the transmission execution ECU is arranged in the destination MAC address area of the relay impossible notification frame.
The data in the data area of the frame received from the transmission execution ECU is copied and arranged in the data area of the relay impossible notification frame. For this reason, the transmission execution ECU that has received the relay impossible notification frame determines which frame of the frames transmitted by the ECU the relay impossible notification frame is based on the data in the data area of the relay impossible notification frame. Can be identified. That is, the transmission execution ECU can determine which frame is not relayed (in other words, it does not reach the transmission destination ECU). The data arranged in the data area of the relay impossible notification frame is “information that can identify to which frame the relay impossible notification frame is transmitted from the transmission execution ECU (hereinafter referred to as a relay impossible frame). Information)).

  As another example, for example, it is assumed that the ECUs 11 to 13 arrange the sequence number of the frame in the VLAN tag area of the frame to be transmitted. In this case, the control unit 25 may arrange the sequence number arranged in the VLAN tag area of the received frame in the VLAN tag area of the relay impossible notification frame. Even in this case, the transmission execution ECU can identify to which frame of the frames transmitted by the ECU the relay disabled notification frame is based on the sequence number in the relay disabled notification frame. . In this case, the sequence number in the relay impossible notification frame corresponds to the aforementioned relay disabled frame information.

  Similar to the abnormality notification frame, the sequence number may be arranged at a specific position in the data area of the frame for the relay impossible notification frame, for example. Further, the relay impossible frame information included in the relay impossible notification frame may be both the sequence number in the frame received from the transmission execution ECU and the data in the data area.

  When generating the relay impossible notification frame, the control unit 25 receives the generated relay disabled notification frame as a port that has received the frame addressed to the disconnected port (that is, the port to which the transmission execution ECU is connected). Send from. Then, the transmitted relay impossible notification frame is received by the transmission execution ECU.

And the control part 25 complete | finishes the said relay impossible notification process, after transmitting a relay impossible notification frame by S330.
According to the Ethernet switch 10 of the fourth embodiment as described above, the transmission execution ECU that has transmitted the frame addressed to the disconnected port can know from the relay impossible notification frame that the transmitted frame is not relayed. For this reason, for example, the transmission execution ECU can appropriately perform fail-safe processing for preventing or suppressing a malfunction caused by a frame transmitted by itself not reaching the transmission destination ECU.

  In addition, when the transmission execution ECU receives the relay impossible notification frame, it can determine that the frame transmitted immediately before is not relayed. included. Therefore, the transmission execution ECU can more correctly determine which frame is not relayed based on the relay impossible frame information in the relay impossible notification frame. For this reason, for example, the transmission execution ECU can more correctly select the fail-safe process to be performed.

In the fourth embodiment, S310 to S330 in FIG. 6 correspond to an example of a relay impossible notification unit.
As mentioned above, although embodiment of this invention was described, this invention can take a various form, without being limited to the said embodiment. The above-mentioned numerical values are also examples, and other values may be used.

  For example, in the abnormality notification frame, the identification code indicating that the frame is the abnormality notification frame may be arranged not only in the VLAN tag area but in any position in the data area. The same applies to the relay impossible notification frame. In addition, the present invention is not limited to the Ethernet switch, and can be similarly applied to relay devices of other communication standards.

  In addition, the functions of one component in the above embodiment may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Further, at least a part of the configuration of the above embodiment may be replaced with a known configuration having the same function. Moreover, you may abbreviate | omit a part of structure of the said embodiment. In addition, at least a part of the configuration of the above embodiment may be added to or replaced with the configuration of the other embodiment. In addition, all the aspects included in the technical idea specified by the wording described in the claims are embodiments of the present invention. In addition to the Ethernet switch 10 described above, various forms such as a communication system including the Ethernet switch 10 as a constituent element, a program for causing a computer to function as the Ethernet switch 10, a medium storing the program, a relay control method, etc. Thus, the present invention can be realized.

  10 ... Ethernet switch, 11-13 ... ECU, 21-23 ... port, 31-33 ... communication line

Claims (11)

A relay device (10) having a plurality of ports (21 to 23) and relaying communication between control devices (11 to 13) connected to the ports via communication lines (31 to 33). And
For each of the plurality of ports, determination means (S120) for determining whether a received frame that is a frame received from the port is normal or abnormal;
A discarding unit (S130) for discarding the abnormal frame that is the received frame determined to be abnormal by the determination unit;
When the determination unit determines that the received frame is abnormal, an abnormality notification frame for notifying that a frame abnormality has occurred is transmitted to a transmission source device that is a control device that is the transmission source of the abnormal frame. Abnormality notification means (S150);
A relay device comprising: The relay device according to claim 1,
The determination means includes
Bit number determination for determining whether the number of bits of the received frame is a normal value;
Performing error detection for detecting data errors in the received frame using error detection data included in the received frame;
It is determined that the number of bits of the received frame is not a normal value by the bit number determination, or when the data error of the received frame is detected by the error detection, the received frame is determined to be abnormal,
Determining that the number of bits of the received frame is a normal value by the number of bits determination, and determining that the received frame is normal when a data error of the received frame is not detected by the error detection;
A relay device characterized by In the relay device according to claim 1 or 2,
The abnormality notification frame includes information capable of identifying which frame of the abnormality notification frame is the frame transmitted from the transmission source device.
A relay device characterized by The relay device according to any one of claims 1 to 3,
For each of the plurality of ports, an abnormality counting unit (S160) that counts the number of times that the received frame is determined to be abnormal by the determination unit;
Port disconnecting means (S170, S180) for excluding, from among the plurality of ports, ports whose count value by the abnormality counting means is equal to or greater than a predetermined threshold from communication relay targets;
A relay device comprising: The relay device according to any one of claims 1 to 3,
For each of the plurality of ports, continuous abnormality counting means (S160, S165) for counting the number of times the received frame is determined to be abnormal by the determination means;
Port disconnecting means (S170, S180) for excluding, from among the plurality of ports, ports whose count value by the continuous abnormality counting means is equal to or greater than a predetermined threshold from communication relay targets;
A relay device comprising: The relay device according to any one of claims 1 to 3,
For each of the plurality of ports, from the number of abnormal receptions that is the number of times that the reception frame is determined to be abnormal by the determination unit, and the number of normal receptions that is the number of times that the reception frame is determined to be normal by the determination unit Calculating means (S210, S215) for calculating an evaluation value representing the frequency at which the received frame becomes abnormal;
Port disconnecting means (S220, S230) for excluding, from the plurality of ports, a port whose evaluation value is equal to or greater than a predetermined threshold from communication relay targets;
A relay device comprising: The relay device according to claim 6,
The calculating means calculates, as the evaluation value, a value obtained by subtracting a value obtained by multiplying the number of normal receptions by a second coefficient from a value obtained by multiplying the number of abnormal receptions by a first coefficient;
A relay device characterized by In the relay device according to claim 6 or 7,
Port restoration means for returning the port to the communication relay target when the evaluation value for the port excluded from the communication relay target by the port disconnection means is equal to or lower than the return threshold value smaller than the threshold value ( S250, S260),
A relay device characterized by In the relay device according to any one of claims 4 to 7,
The port disconnecting means performs a process of stopping the operation of the transceiver of the port as a process of excluding the port from communication relay targets;
A relay device characterized by The relay device according to any one of claims 4 to 9,
When a frame addressed to the control device connected to the disconnected port is received from a port other than the disconnected port that is a port excluded from communication relay targets by the port disconnecting unit among the plurality of ports. Relay disabling notification means (S310 to S330) for transmitting a relay disapproval notification frame for notifying that the relay of the frame is impossible to the transmitting execution device that is a control device that is a transmission source of the frame;
A relay device characterized by The relay device according to claim 10,
The relay impossible notification frame includes information that can identify to which frame of the frames transmitted from the transmission execution device the relay impossible notification frame is,
A relay device characterized by