JP2022024630A - On-vehicle hub and on-vehicle system - Google Patents

Abstract

To provide an on-vehicle hub and an on-vehicle system, which can improve security with reduced manufacturing cost.SOLUTION: In an on-vehicle system 1, an on-vehicle hub 20 includes L2 switching means 50 and auxiliary switching means 70. In the case of not unicast in which an L2 frame is transferred to a transmission source VLAN, the L2 switching means 50 transfers to the auxiliary switching means 70 the L2 frame in which a transmission source VLAN ID is inserted. The auxiliary switching means 70 acquires a destination node which corresponds to an on-vehicle information ID extracted from the L2 frame, and a destination VLAN ID which corresponds to the destination node, and then replaces the transmission source VLAN ID inserted into the L2 frame with the acquired destination VLAN ID to transfer the L2 frame to the L2 switching means 50. Based on the destination VLAN ID included in the L2 frame, the L2 switching means 50 transfers to a destination port the L2 frame in which the destination VLAN ID has been removed.SELECTED DRAWING: Figure 1

Description

The present invention relates to an in-vehicle hub and an in-vehicle system.

There is known an in-vehicle system in which a plurality of devices mounted on a vehicle are connected to each other so as to be communicable with each other via a communication interface to form an in-vehicle network (see, for example, Patent Document 1).

In the vehicle-mounted system disclosed in Patent Document 1, the vehicle-mounted hub can virtually divide the vehicle-mounted network into a plurality of segments by means of a virtual local area network (VLAN).

Within the segment, the vehicle-mounted hub transfers frames based on the media access control (MAC) address. On the other hand, between the segments, the vehicle-mounted hub blocks the transfer of frames. This makes it possible to improve the security of the in-vehicle network.

Japanese Unexamined Patent Publication No. 2019-9614

In the above-mentioned in-vehicle system, when information is shared between different segments, it is necessary to separately provide a layer 3 switching means having a routing function in order to transfer frames between the segments.

Layer 3 switching means forward frames between segments based on Internet Protocol (IP) addresses.

As described above, in the conventional in-vehicle system, when the in-vehicle network is divided into a plurality of segments, the frame is transferred based on the MAC address within the segment, and the frame is transferred between the segments based on the IP address. Will be done. For this reason, there has been a problem that the configuration of the in-vehicle network becomes complicated and the manufacturing cost of the in-vehicle system increases.

The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide an in-vehicle hub and an in-vehicle system capable of improving the security of an in-vehicle network while suppressing an increase in manufacturing cost.

The vehicle-mounted hub according to the embodiment of the present invention has a plurality of ports that can be set to belong to different segments in the vehicle-mounted network, and includes a layer 2 switching means and an auxiliary switching means connected to the layer 2 switching means. .. The layer 2 switching means includes a layer 2 receiving unit and a layer 2 processing unit. The layer 2 receiving unit receives a frame including the MAC address of the source node, the MAC address of the destination node, and the vehicle-mounted message including the vehicle-mounted information ID from the source port connected to the source node. When the layer 2 processing unit determines that the frame is not a unicast frame forwarded to a port in the first segment to which the source port belongs, the first segment ID assigned to the first segment for the frame. Is inserted to transfer the frame to the auxiliary switching means. The auxiliary switching means includes an auxiliary storage unit, an extraction unit, an acquisition unit, and a frame processing unit. The auxiliary storage unit stores information that associates the vehicle-mounted information ID with the destination node to which the vehicle-mounted message is transmitted and the second segment ID assigned to the second segment to which the destination port connected to the destination node belongs. .. The extraction unit extracts the vehicle-mounted information ID from the frame received from the layer 2 processing unit. The acquisition unit identifies the destination node associated with the extracted vehicle-mounted information ID based on the information, and acquires the second segment ID associated with the identified destination node. The frame processing unit replaces the first segment ID inserted in the frame with the acquired second segment ID, and transfers the frame to the layer 2 switching means. The layer 2 processing unit transfers the frame from which the second segment ID has been removed to the destination port based on the second segment ID included in the frame received from the frame processing unit.

When the frame processing unit determines that the second segment ID is different from the first segment ID, the frame processing unit replaces the first segment ID inserted in the frame with the second segment ID and transfers the frame to the layer 2 switching means. It is preferable to do so.

When the vehicle-mounted information ID is not extracted in the extraction unit, it is preferable that the frame processing unit discards the frame.

If the destination node is not identified in the acquisition unit, the frame processing unit preferably discards the frame.

The vehicle-mounted system according to another aspect of the present invention includes the vehicle-mounted hub described above and a plurality of nodes housed in the vehicle-mounted hub.

According to the present invention, it is possible to provide an in-vehicle hub and an in-vehicle system that can improve the security of an in-vehicle network while suppressing an increase in manufacturing cost.

FIG. 1 is an overall schematic configuration diagram of an in-vehicle system according to the present embodiment. FIG. 2 is a diagram showing a configuration of a layer 2 frame according to the present embodiment. FIG. 3 is a functional block configuration diagram of the layer 2 switching means according to the present embodiment. FIG. 4 is a diagram showing an example of a MAC address table for associating a port number and a MAC address, which is held by the layer 2 switching means according to the present embodiment. FIG. 5 is a diagram showing an example of a VLAN ID table for associating a port number and a VLAN ID, which is held by the layer 2 switching means according to the present embodiment. FIG. 6 is a functional block configuration diagram of the auxiliary switching means according to the present embodiment. FIG. 7 is a diagram showing an example of an in-vehicle information ID table for associating an in-vehicle information ID and a destination node, which is held by the auxiliary switching means according to the present embodiment. FIG. 8 is a diagram showing an example of a destination VLAN ID table that associates a destination node, a port number, and a VLAN ID, which is held by the auxiliary switching means according to the present embodiment. FIG. 9 is a diagram showing an operation flow 1 of the layer 2 switching means in the frame transfer procedure according to the present embodiment. FIG. 10 is a diagram showing an operation flow 2 of the layer 2 switching means in the frame transfer procedure according to the present embodiment. FIG. 11 is a diagram showing an operation flow of the auxiliary switching means in the frame transfer procedure according to the present embodiment. FIG. 12 is a diagram showing a sequence in an operation example of the frame transfer procedure according to the present embodiment. FIG. 13 is an overall schematic configuration diagram of an in-vehicle system according to a modified example of the present embodiment.

Hereinafter, the in-vehicle hub and the in-vehicle system according to the present embodiment will be described in detail with reference to the drawings. The same functions and configurations are designated by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

[Overall outline configuration of in-vehicle system]
FIG. 1 is an overall schematic configuration diagram of an in-vehicle system 1 according to the present embodiment. The in-vehicle system 1 is mounted on the vehicle and controls the communication of the in-vehicle network formed in the vehicle. Communication standards that define Layer 1 (physical layer) and Layer 2 (data link layer) of the Open Systems Interconnection (OSI) reference model apply to in-vehicle networks. In the present embodiment, the vehicle-mounted network is a network having Ethernet (registered trademark) as a communication standard.

As shown in FIG. 1, the vehicle-mounted system 1 includes nodes 10a to 10d and a vehicle-mounted hub 20. The in-vehicle network is composed of nodes 10a to 10d and an in-vehicle hub 20. The number of nodes is not limited to four, and may be other values.

The nodes 10a to 10d are devices mounted on the vehicle, for example, an engine control unit (ECU). The ECU mounted on the vehicle includes a vehicle control system ECU, a traveling safety control system ECU, a body control system ECU, a power train control system ECU, a sensing system ECU, an information communication system ECU, and the like.

The nodes 10a to 10d are connected to the vehicle-mounted hub 20 by using the cables 30a to 30d. In this embodiment, the cables 30a to 30d are communication cables used in Ethernet.

Media access control (MAC) addresses Ma to Md are assigned to the nodes 10a to 10d. The MAC address is used at layer 2 to identify a node connected to the vehicle-mounted network.

Each of the nodes 10a to 10d transmits and receives a message peculiar to the vehicle-mounted network (hereinafter referred to as a vehicle-mounted message). The vehicle-mounted message includes data and an vehicle-mounted information ID for identifying an item of the data. The data is, for example, data relating to vehicle operation.

The data contained in the in-vehicle message is classified by item. This item is defined when the system of the entire vehicle is developed. In the in-vehicle network, the data in each item is used in a specific node. For example, when the data item is "vehicle speed", the "meter ECU" is determined as the node that uses the data. Therefore, when developing a system for the entire vehicle, nodes that use the data in each item can be defined in advance.

The vehicle-mounted information ID included in the vehicle-mounted message is assigned to a data item when the system of the entire vehicle is developed. The data item is also referred to as "vehicle-mounted information".

Each of the nodes 10a to 10d includes the vehicle-mounted message in the layer 2 frame and transmits / receives the vehicle-mounted message. In this embodiment, the layer 2 frame is an Ethernet frame.

FIG. 2 is a diagram showing a configuration of a layer 2 frame according to the present embodiment. As shown in FIG. 2, the layer 2 frame includes a preamble, a layer 2 header, a layer 2 payload, and a frame check sequence (FCS).

The preamble is a bit string that causes a node connected to the in-vehicle network to recognize the start of frame transmission and gives timing for synchronization.

The layer 2 header has a source MAC address and a destination MAC address. The source MAC address is the MAC address assigned to the source node that sends the frame. The destination MAC address is the MAC address assigned to the destination node that receives the frame.

As will be described later, the in-vehicle hub 20 inserts a virtual local area network tag (VLAN tag) including a virtual local area network identifier (VLAN ID) into the layer 2 header. be able to.

The layer 2 payload has an in-vehicle message. As described above, the vehicle-mounted message includes data and an vehicle-mounted information ID for identifying an item (vehicle-mounted information) of the data. Each of the nodes 10a to 10d writes an in-vehicle message to the layer 2 frame payload.

The FCS has a value used for frame error detection.

As shown in FIG. 1, the vehicle-mounted hub 20 is a device mounted on a vehicle and accommodates nodes 10a to 10d. The vehicle-mounted hub 20 transfers layer 2 frames transmitted and received between the nodes.

The vehicle-mounted hub 20 includes a layer 2 switching means 50 and an auxiliary switching means 70. The layer 2 switching means 50 is connected to the auxiliary switching means 70 by using a signal line (bus) 90.

The layer 2 switching means 50 includes ports 51a to 51d and ports 51e in the hub. Cables 30a to 30d are connected to the ports 51a to 51d, respectively. A signal line 90 is connected to the port 51e in the hub.

The layer 2 switching means 50 can virtually (logically) divide the vehicle-mounted network into a plurality of segments (hereinafter referred to as VLAN segments) by the virtual local area network (VLAN). A node connected to a port belonging to the same VLAN segment is included in the same local area network (LAN).

For example, of the two VLAN segments, one of the VLAN segments has a port to which a highly reliable node (ECU) can be connected, and the other VLAN segment has a low reliability node (ECU) connected to it. Possible ports belong. In a highly reliable ECU, high reliability is required for data transmitted and received. A low-reliability ECU does not require high reliability for transmitted and received data. The highly reliable ECU is an indispensable device for vehicle operation and is incorporated in the vehicle at the time of shipment of the vehicle. The low-reliability ECU is an auxiliary device and is attached to the vehicle after the vehicle is shipped.

With such a configuration, even if a malicious device is connected in the other VLAN segment, the message transferred in the one VLAN segment does not reach the other VLAN segment. Therefore, the security of the in-vehicle network can be improved. Further, even if the malicious device transmits the spoofing information, the spoofing information does not reach one of the VLAN segments, so that the security of the in-vehicle network can be improved.

Further, of the two VLAN segments, one of the VLAN segments has a port to which a node (ECU) that shares information of a certain system can be connected, and the other VLAN segment shares information of another system. The port to which the node (ECU) can be connected belongs. Exceptionally, layer 2 frame transfer is performed between the VLAN segments only when the information is shared between the VLAN segments.

Specifically, the meter ECU is connected to the port belonging to one of the two VLAN segments, and the accessory meter ECU is connected to the port belonging to the other VLAN segment. In this case, since the meter ECU and the accessory meter ECU share the data of the vehicle-mounted information "vehicle speed", the layer 2 frame is transferred between the VLAN segments.

The layer 2 switching means 50 assigns each of the ports 51a to 51d to one of the plurality of VLAN segments in order to divide the vehicle-mounted network into a plurality of VLAN segments. The layer 2 switching means 50 makes the in-hub port 51e belong to a plurality of VLAN segments.

In the present embodiment, the layer 2 switching means 50 divides the vehicle-mounted network into three VLAN segments (VLAN segments # 1, # 2, # 3). Specifically, the layer 2 switching means 50 makes the ports 51a and 51b belong to the VALN segment # 1. The layer 2 switching means 50 makes the port 51c belong to the VLAN segment # 2. The layer 2 switching means 50 makes the port 51d belong to the VLAN segment # 3. The layer 2 switching means 50 makes the in-hub port 51e belong to the VLAN segments # 1 to # 3.

In addition, VLAN ID = VL1 to VL3 are assigned to VLAN segments # 1 to # 3, respectively.

The layer 2 switching means 50 sets the ports 51a to 51d as ports that do not use the VLAN tag. The layer 2 switching means 50 sets the in-hub port 51e as a port that uses a VLAN tag.

Each of the nodes 10a to 10d cannot freely select a connectable port, and is connected only to a port having a predetermined port number. For example, when the ports 51a to 51d have port numbers P1 to P4, respectively, the connection relationship between the nodes 10a to 10d and the ports 51a to 51d is as follows. The node 10a can be connected only to the port 51a having the port number P1. The node 10b can be connected only to the port 51b having the port number P2. The node 10c can be connected only to the port 51c having the port number P3. The node 10d can be connected only to the port 51d having the port number P4.

With such a configuration, for example, even if the node 10d impersonates the node 10a by using the MAC address of the node 10a, the in-vehicle information that reaches only the ports 51a and 51b belonging to the VLAN segment # 1 can be transmitted to the port 51d. Cannot be removed from.

The layer 2 switching means 50 receives the next frame as the layer 2 frame, as will be described later. The source VLAN segment is a VLAN segment to which the port (source port) that received the layer 2 frame belongs.
-Unicast frame that does not cause flooding (in the source VLAN segment) -Unicast frame that causes flooding (in the source VLAN segment) -Broadcast frame

Flooding occurs when the destination MAC address in the unicast frame is not associated with a port in the source VLAN segment. In this case, the layer 2 switching means 50 causes flooding in the source VLAN segment and transfers the received unicast frame to all ports (excluding the source port) in the source VLAN segment.

A unicast frame that does not cause flooding is also referred to as a unicast frame that is forwarded to a port in the source VLAN segment. The unicast frame and the broadcast frame that cause flooding are also referred to as frames that are not unicast frames that are forwarded to the port in the source VLAN segment.

The layer 2 switching means 50 transfers a layer 2 frame within the same VLAN segment without using a VLAN tag.

On the other hand, the layer 2 switching means 50 transfers a layer 2 frame between different VLAN segments by using a VLAN tag. Specifically, the layer 2 switching means 50 inserts a VLAN tag including the source VLAN ID of the source VLAN segment into the layer 2 frame, and inserts the layer 2 frame via the in-hub port 51e. Transfer to the auxiliary switching means 70. The source VLAN segment is also referred to as a first segment. The source VLAN ID is also referred to as a first segment ID.

The auxiliary switching means 70 transfers layer 2 frames between different VLAN segments. In the present embodiment, the auxiliary switching means 70 is composed of a microcontroller that controls the layer 2 switching means 50. The microcomputer has a built-in software having a setting function and software having an auxiliary switch function. The setting function changes / adjusts the settings necessary for the operation of the layer 2 switching means 50 according to the situation. The auxiliary switch function transfers layer 2 frames between different VLAN segments.

Upon receiving the layer 2 frame from the layer 2 switching means 50, the auxiliary switching means 70 reads the vehicle-mounted information ID in the layer 2 frame and uses the data in the item (vehicle-mounted information) to which the vehicle-mounted information ID is assigned. Identify the node (destination node).

When the auxiliary switching means 70 identifies a specific node (destination node), the auxiliary switching means 70 identifies the VLAN ID (destination VLAN ID) of the VLAN segment (destination VLAN segment) to which the port (destination port) connected to the specific node (destination node) belongs. ). The auxiliary switching means 70 replaces the VLAN tag including the source VLAN ID inserted in the layer 2 frame with the VLAN tag including the destination VLAN ID, and transfers the layer 2 frame to the layer 2 switching means 50. The destination VLAN segment is also referred to as a second segment. The destination VLAN ID is also referred to as a second segment ID.

When the layer 2 switching means 50 receives the layer 2 frame from the auxiliary switching means 70, the layer 2 switching means 50 transfers the layer 2 frame to the destination port based on the destination VLAN ID in the layer 2 frame. At this time, the layer 2 switching means 50 removes the VLAN tag including the destination VLAN ID from the layer 2 frame and transfers the layer 2 frame.

[Functional block configuration of in-vehicle system]
Next, the functional block configuration of the in-vehicle system 1 will be described. Specifically, the functional block configuration of the layer 2 switching means 50 and the auxiliary switching means 70 of the vehicle-mounted hub 20 will be described. Hereinafter, only the parts related to the features in the present embodiment will be described. Therefore, it goes without saying that the layer 2 switching means 50 and the auxiliary switching means 70 include other functional blocks that are not directly related to the features in the present embodiment.

First, the functional block configuration of the layer 2 switching means 50 will be described. FIG. 3 is a functional block configuration diagram of the layer 2 switching means 50 according to the present embodiment. As shown in FIG. 3, the layer 2 switching means 50 includes ports 51a to 51d, an in-hub port 51e, a control unit 52, a segment setting unit 53, a layer 2 storage unit 55, a layer 2 receiving unit 57, and a layer 2 processing unit. 59 is provided.

The layer 2 switching means 50 is connected to the nodes 10a to 10d via the ports 51a to 51d. Port numbers P1 to P4 are assigned to the ports 51a to 51d. Layer 2 frames are input to each of the ports 51a to 51d.

The control unit 52 controls the entire processing in the layer 2 switching means 50. Specifically, the control unit 52 controls the operation of each of the segment setting unit 53, the layer 2 storage unit 55, the layer 2 receiving unit 57, and the layer 2 processing unit 59.

The segment setting unit 53 makes each of the ports 51a to 51d belong to one of the VLAN segments # 1 to # 3 based on the input from the outside. Specifically, the segment setting unit 53 associates VLAN ID = VL1 with the port numbers P1 and P2 so that the ports 51a and 51b belong to the VALN segment # 1. The segment setting unit 53 associates VLAN ID = VL2 with the port number P3 so that the port 51c belongs to the VALN segment # 2. The segment setting unit 53 associates VLAN ID = VL3 with the port number P4 so that the port 51d belongs to the VALN segment # 3.

The layer 2 storage unit 55 stores information for associating a port number with a MAC address. FIG. 4 is a diagram showing an example of a MAC address table for associating a port number and a MAC address, which is held by the layer 2 switching means 50 according to the present embodiment. In the present embodiment, as shown in FIG. 4, the layer 2 storage unit 55 stores a MAC address table that associates the port numbers P1 to P4 of the ports 51a to 51d with the MAC addresses Ma to Md of the nodes 10a to 10d. do.

The layer 2 storage unit 55 stores the information set by the segment setting unit 53 that associates the port number with the VLAN ID. FIG. 5 is a diagram showing an example of a VLAN ID table for associating a port number and a VLAN ID, which is held by the layer 2 switching means 50 according to the present embodiment. In the present embodiment, as shown in FIG. 5, the layer 2 storage unit 55 stores the VLAN ID table that associates the port numbers P1 to P4 of the ports 51a to 51d with the VLAN ID = VL1 to VL3.

The layer 2 receiving unit 57 receives the layer 2 frame from the source port connected to the source node. The layer 2 processing unit 59 determines whether or not the layer 2 frame received by the layer 2 receiving unit 57 is a unicast frame transferred to a port in the source VLAN segment to which the source port belongs.

Specifically, the layer 2 processing unit 59 determines whether or not the layer 2 processing unit 59 is a unicast frame capable of specifying a port in the source VLAN segment from the destination MAC address of the layer 2 frame. As will be described later, the layer 2 processing unit 59 refers to the MAC address table and the VLAN ID table stored in the layer 2 storage unit 55 in the determination.

When the layer 2 processing unit 59 determines that the layer 2 frame is the above-mentioned unicast frame, the layer 2 processing unit 59 sets the layer 2 frame in the port having the port number associated with the destination MAC address in the source VLAN segment. Forward. In this case, the layer 2 processing unit 59 transfers the layer 2 frame without using the VLAN tag.

On the other hand, when the layer 2 processing unit 59 determines that the layer 2 frame is not the above-mentioned unicast frame, the layer 2 processing unit 59 inserts the source VLAN ID of the source VLAN segment into the layer 2 frame. Specifically, the layer 2 processing unit 59 inserts a VLAN tag including a source VLAN ID into the layer 2 header of the layer 2 frame.

The layer 2 processing unit 59 transfers the layer 2 frame in which the VLAN tag including the source VLAN ID is inserted to the auxiliary switching means 70 via the in-hub port 51e. When the layer 2 processing unit 59 determines that the layer 2 frame is not the above-mentioned unicast frame, the layer 2 processing unit 59 does not use the VLAN tag for all the remaining ports in the source VLAN segment as described later. It also transfers layer 2 frames.

When the layer 2 processing unit 59 receives the layer 2 frame from the auxiliary switching means 70 via the in-hub port 51e, the layer 2 processing unit 59 transfers the layer 2 frame to the destination port based on the destination VLAN ID in the layer 2 frame. At this time, the layer 2 processing unit 59 removes the VLAN tag including the destination VLAN ID from the layer 2 frame and transfers the layer 2 frame.

Next, the functional block configuration of the auxiliary switching means 70 will be described. FIG. 6 is a functional block configuration diagram of the auxiliary switching means 70 according to the present embodiment. As shown in FIG. 6, the auxiliary switching means 70 includes a control unit 71, an auxiliary storage unit 72, an extraction unit 73, an acquisition unit 75, and a frame processing unit 77.

The control unit 71 controls the entire processing in the auxiliary switching means 70. Specifically, the control unit 71 controls the operations of the auxiliary storage unit 72, the extraction unit 73, the acquisition unit 75, and the frame processing unit 77.

The auxiliary storage unit 72 transmits information for associating an in-vehicle information ID for identifying an item (vehicle-mounted information) of data included in an in-vehicle message with one or more specific nodes (destination nodes) that use the data. Remember. As mentioned above, the association is determined at the time of system development of the entire vehicle.

FIG. 7 is a diagram showing an example of an in-vehicle information ID table for associating an in-vehicle information ID and a destination node, which is held by the auxiliary switching means 70 according to the present embodiment. In the present embodiment, as shown in FIG. 7, the auxiliary storage unit 72 stores the vehicle-mounted information ID table that associates the vehicle-mounted information IDs = IV1 and IV2 with the destination nodes 10a to 10c.

In the present embodiment, the data in the item to which the vehicle-mounted information ID = IV1 is assigned is acquired at the node 10a and used at the node 10c. Therefore, the vehicle-mounted message including the vehicle-mounted information ID = IV1 is transmitted from the node 10a to the node 10c. Therefore, the vehicle-mounted information ID = IV1 is associated with the node 10c.

The layer 2 frame used for transmitting the vehicle-mounted message including the vehicle-mounted information ID = IV1 is a unicast frame having the MAC address Mc of the node 10c as the destination MAC address. As shown in FIG. 1, the port 51c (destination port) connected to the node 10c is included in the VLAN segment # 1 (source VLAN segment) to which the port 51a (source port) connected to the node 10a belongs. not exist. Therefore, the layer 2 frame used for transmitting the vehicle-mounted message including the vehicle-mounted information ID = IV1 is a unicast frame that causes flooding (a frame that is not a unicast frame transferred to a port in the source VLAN segment). ..

In the present embodiment, the data in the item to which the vehicle-mounted information ID = IV2 is assigned is acquired by the node 10b and used by the nodes 10a and 10c. Therefore, the vehicle-mounted message including the vehicle-mounted information ID = IV2 is transmitted from the node 10b to the nodes 10a and 10c. Therefore, the vehicle-mounted information ID = IV2 is associated with the nodes 10a and 10c.

As shown in FIG. 1, the port 51a (destination port) connected to the node 10a and the port 51b (source port) connected to the node 10b include all ports in the VLAN segment # 1 that do not use the VLAN tag. Configure. Similarly, the port 51c (destination port) connected to the node 10c constitutes all ports in the VLAN segment # 2 that do not use the VLAN tag. Therefore, the layer 2 frame used for transmitting the vehicle-mounted message including the vehicle-mounted information ID = IV2 is a broadcast frame having a broadcast address (a frame that is not a unicast frame transferred to a port in the source VLAN segment).

The auxiliary storage unit 72 further associates a specific node (destination node) that uses the data included in the in-vehicle message with the information (for example, the VLAN ID table in FIG. 5) that associates the port number with the VLAN ID. Memorize information. The specific node (destination node) is associated with the port number of the port that can be connected to the specific node (destination node).

FIG. 8 is a diagram showing an example of a destination VLAN ID table for associating a destination node, a port number, and a VLAN ID, which is held by the auxiliary switching means 70 according to the present embodiment. In the present embodiment, as shown in FIG. 8, the auxiliary storage unit 72 stores the destination VLAN ID table that associates the destination nodes 10a to 10d, the port numbers P1 to P4, and the VLAN ID = VL1 to VL3. The association between the port numbers P1 to P4 and the VLAN ID = VL1 to VL3 in FIG. 8 is the same as the association between the port numbers P1 to P4 and the VLAN ID = VL1 to VL3 in FIG. ..

The extraction unit 73 receives the layer 2 frame in which the VLAN tag including the source VLAN ID is inserted from the port 51e in the hub of the layer 2 switching means 50. The extraction unit 73 extracts the source VLAN ID from the layer 2 header of the received layer 2 frame.

The extraction unit 73 extracts the vehicle-mounted information ID from the layer 2 payload of the received layer 2 frame. If the vehicle-mounted information ID cannot be extracted, the extraction unit 73 notifies the frame processing unit 77 of a signal indicating invalidity.

The acquisition unit 75 refers to the vehicle-mounted information ID table and identifies one or more destination nodes associated with the vehicle-mounted information ID extracted by the extraction unit 73. If the destination node cannot be identified, the acquisition unit 75 notifies the frame processing unit 77 of a signal indicating invalidity.

The acquisition unit 75 refers to the destination VLAN ID table and acquires the destination VLAN ID associated with each identified destination node.

The frame processing unit 77 receives the layer 2 frame in which the VLAN tag including the source VLAN ID is inserted from the port 51e in the hub of the layer 2 switching means 50. The frame processing unit 77 temporarily stores the received layer 2 frame.

The frame processing unit 77 determines whether or not the destination VLAN ID acquired by the acquisition unit 75 is different from the source VLAN ID extracted by the extraction unit 73.

When the frame processing unit 77 determines that the destination VLAN ID is different from the source VLAN ID, the frame processing unit 77 reads out the temporarily stored layer 2 frame. The frame processing unit 77 replaces the VLAN tag including the source VLAN ID inserted in the layer 2 header of the read layer 2 frame with the VLAN tag including the destination VLAN ID.

Specifically, the frame processing unit 77 overwrites the VLAN tag including the source VLAN ID with the VLAN tag including the destination VLAN ID in the layer 2 header of the layer 2 frame. Instead of overwriting the VLAN tag, the frame processing unit 77 may overwrite the layer 2 header of the layer 2 frame with the new layer 2 header in the layer 2 frame. The new layer 2 header includes a source MAC address, a destination MAC address, and a VLAN tag containing the destination VLAN ID.

When the VLAN ID is replaced, the frame processing unit 77 transfers the layer 2 frame to the in-hub port 51e of the layer 2 switching means 50 via the signal line 90.

On the other hand, when the frame processing unit 77 determines that the destination VLAN ID is the same as the source VLAN ID, the frame processing unit 77 does not read the temporarily stored layer 2 frame and does not transfer the layer 2 frame. In this case, in the layer 2 switching means 50, the layer 2 frame has already been transmitted to the destination node.

When the extraction unit 73 or the acquisition unit 75 notifies the frame processing unit 77 of a signal indicating invalidity, the frame processing unit 77 does not read the temporarily stored layer 2 frame, does not transfer the layer 2 frame, or temporarily stores the layer 2 frame. Is destroyed.

[Operation of in-vehicle system]
Next, the operation of the in-vehicle system 1 will be described. Specifically, the frame transfer procedure in the vehicle-mounted hub 20 will be described. Specifically, the operation flows 1 and 2 of the layer 2 switching means 50 and the operation flow of the auxiliary switching means 70 in the frame transfer procedure, and the sequence in the operation example of the frame transfer procedure will be described.

[Operation flow 1 of layer 2 switching means 50]
First, the operation flow of the layer 2 switching means 50 from the reception of the layer 2 frame via the source port connected to the source node to the transfer of the layer 2 frame will be described.

FIG. 9 is a diagram showing an operation flow 1 of the layer 2 switching means 50 in the frame transfer procedure according to the present embodiment. As shown in FIG. 9, the layer 2 receiving unit 57 receives the layer 2 frame via the source port connected to the source node (S1). Specifically, the layer 2 receiving unit 57 receives the layer 2 frame via each of the ports 51a to 51d.

The layer 2 processing unit 59 determines whether or not the received layer 2 frame is a unicast frame transferred to a port in the source VLAN segment to which the source port belongs (S3).

Specifically, the layer 2 processing unit 59 extracts the destination MAC address of the received layer 2 frame and determines whether or not the extracted destination MAC address is a broadcast address. When the destination MAC address is a broadcast address, in S3, the layer 2 processing unit 59 determines that the received layer 2 frame is not a unicast frame transferred to the port in the source VLAN segment. In this case, the layer 2 frame is a broadcast frame.

On the other hand, when the destination MAC address is not a broadcast address, the layer 2 processing unit 59 identifies the port number of the source port. The layer 2 processing unit 59 refers to the VLAN ID table and acquires the VLAN ID associated with the identified port number as the source VLAN ID.

The layer 2 processing unit 59 extracts the destination MAC address from the received layer 2 frame, refers to the MAC address table, and acquires the port number associated with the extracted destination MAC address. The layer 2 processing unit 59 refers to the VLAN ID table and determines whether or not the acquired port number exists among the port numbers associated with the acquired source VLAN ID.

If the acquired port number does not exist in the port number associated with the source VLAN ID, the layer 2 processing unit 59 transfers the received layer 2 frame to the port in the source VLAN segment in S3. Judge that it is not a unicast frame to be played. In this case, the layer 2 frame is a unicast frame that causes flooding.

On the other hand, when the acquired port number exists in the port number associated with the source VLAN ID, in S3, the layer 2 processing unit 59 receives the layer 2 frame as a port in the source VLAN segment. Judge that it is a unicast frame to be transferred to. In this case, the layer 2 frame is a unicast frame that does not cause flooding.

When the layer 2 processing unit 59 determines that the received layer 2 frame is a unicast frame to be transferred to the port in the source VLAN segment (S3: YES), the layer 2 processing unit 59 receives the received layer 2 frame to the port corresponding to the destination MAC address. The layer 2 frame is transferred (S5). Specifically, the layer 2 processing unit 59 transfers the received layer 2 frame to the port having the port number associated with the destination MAC address without using the VLAN tag. When the layer 2 processing unit 59 executes the processing of S5, the layer 2 processing unit 59 ends this operation flow.

On the other hand, when the layer 2 processing unit 59 determines that the received layer 2 frame is not a unicast frame transferred to the port in the source VLAN segment (S3: NO), the layer 2 processing unit 59 performs the following operation. The layer 2 processing unit 59 inserts a VLAN tag including the acquired source VLAN ID into the layer 2 header of the received layer 2 frame (S7). The layer 2 processing unit 59 transfers the layer 2 frame into which the VLAN tag including the source VLAN ID is inserted to the auxiliary switching means 70 via the in-hub port 51e (S7). As described above, when the layer 2 frame is a unicast frame or a broadcast frame that causes flooding, the layer 2 frame into which the VLAN tag is inserted is transferred to the auxiliary switching means 70.

The layer 2 processing unit 59 subsequently transfers the received layer 2 frame to all the remaining ports in the source VLAN segment without using the VLAN tag (S9). For example, in the case of a layer 2 frame including the vehicle-mounted information ID = IV1 (see FIG. 7), the layer 2 processing unit 59 uses the received layer 2 frame as the VLAN segment # 1 due to the occurrence of flooding in the VLAN segment # 1. Forward to the remaining ports 51b in. Further, in the case of a layer 2 frame including the vehicle-mounted information ID = IV2 (see FIG. 7), the layer 2 processing unit 59 broadcasts in the VLAN segment # 1 and receives the received layer 2 frame in the VLAN segment # 1. Forward to the remaining port 51a. Thus, if the layer 2 frame is a unicast frame or a broadcast frame that causes flooding, the layer 2 frame without the VLAN tag inserted is forwarded to all the remaining ports in the source VLAN segment. Will be done.

The processing of S9 may be performed before the processing of S7 or at the same time as the processing of S7. When the layer 2 processing unit 59 executes the processing of S7 and S9, the layer 2 processing unit 59 ends this operation flow.

[Operation flow 2 of layer 2 switching means 50]
Next, the operation flow of the layer 2 switching means 50 from the reception of the layer 2 frame via the in-hub port 51e connected to the auxiliary switching means 70 to the transfer of the layer 2 frame will be described.

FIG. 10 is a diagram showing an operation flow 2 of the layer 2 switching means 50 in the frame transfer procedure according to the present embodiment. As shown in FIG. 10, the layer 2 processing unit 59 receives the layer 2 frame in which the VLAN tag including the destination VLAN ID is inserted via the in-hub port 51e connected to the auxiliary switching means 70 (S11). ..

The layer 2 processing unit 59 extracts the destination VLAN ID from the layer 2 header of the received layer 2 frame (S13). The layer 2 processing unit 59 selects the destination VLAN segment to which the extracted destination VALN ID is assigned (S15).

The layer 2 processing unit 59 removes the VLAN tag including the destination VLAN ID from the layer 2 header of the received layer 2 frame, and transfers the layer 2 frame from which the destination VLAN tag has been removed to the selected destination VLAN segment (S17).

Specifically, the layer 2 processing unit 59 extracts the destination MAC address from the layer 2 header of the received layer 2 frame. When the layer 2 processing unit 59 determines that the extracted destination MAC address is a broadcast address, the layer 2 processing unit 59 transfers the layer 2 frame from which the VLAN tag has been removed to all the ports in the selected destination VLAN segment. In this case, the layer 2 frame is a broadcast frame.

When the layer 2 processing unit 59 determines that the extracted destination MAC address is not a broadcast address, the layer 2 processing unit 59 refers to the MAC address table and acquires the port number associated with the extracted destination MAC address. In this case, the layer 2 frame is a unicast frame that causes flooding (within the source VLAN segment).

The layer 2 processing unit 59 refers to the VLAN ID table and determines whether or not the acquired port number exists among the port numbers associated with the destination VLAN ID. When the acquired port number exists in the port number associated with the destination VLAN ID, the layer 2 processing unit 59 has acquired the layer 2 frame from which the VLAN tag has been removed, which exists in the destination VLAN segment. Forward to the port with the port number.

On the other hand, if the acquired port number does not exist in the port number associated with the destination VLAN ID, the layer 2 processing unit 59 uses the layer 2 frame from which the VLAN tag has been removed to be used as the VLAN tag in the destination VLAN segment. Forward to all unused ports. For example, if the layer 2 switching means 50 has not learned the association between the port number of the destination port and the destination MAC address in the destination VLAN segment, flooding will occur. In this case, the layer 2 switching means 50 forwards the layer 2 frame to all the ports in the destination VLAN segment.

When the layer 2 processing unit 59 executes the processing of S17, the layer 2 processing unit 59 ends this operation flow.

[Operation flow of auxiliary switching means 70]
Next, the operation flow from the reception of the layer 2 frame to the transfer of the layer 2 frame in the auxiliary switching means 70 will be described.

FIG. 11 is a diagram showing an operation flow of the auxiliary switching means 70 in the frame transfer procedure according to the present embodiment. As shown in FIG. 11, the extraction unit 73 receives the layer 2 frame in which the VLAN tag including the source VLAN ID is inserted via the in-hub port 51e of the layer 2 switching means 50 (S21).

The extraction unit 73 extracts the vehicle-mounted information ID from the layer 2 payload of the received layer 2 frame, and extracts the source VLAN ID from the layer 2 header of the received layer 2 frame (S23). The acquisition unit 75 refers to the vehicle-mounted information ID table and identifies one or more destination nodes associated with the vehicle-mounted information ID extracted by the extraction unit 73. The acquisition unit 75 refers to the destination VLAN ID table and acquires the destination VLAN ID associated with each identified destination node (S25).

The frame processing unit 77 determines whether or not each destination VLAN ID acquired by the acquisition unit 75 is different from the source VLAN ID extracted by the extraction unit 73 (S27).

When the frame processing unit 77 determines that the destination VLAN ID is different from the source VLAN ID (S27: YES), the frame processing unit 77 inserts a VLAN tag including the source VLAN ID inserted in the layer 2 header of the layer 2 frame into the destination VLAN ID. Replace with a VLAN tag containing. When the VLAN tag is replaced, the frame processing unit 77 transfers the layer 2 frame in which the VLAN tag including the destination VLAN ID is inserted to the in-hub port 51e of the layer 2 switching means 50 (S29). When the frame processing unit 77 executes the processing of S29, the main operation flow ends.

On the other hand, when the frame processing unit 77 determines that the destination VLAN ID is the same as the source VLAN ID (S27: NO), the layer 2 frame is not transferred and the operation flow ends. In this case, in the layer 2 switching means 50, the layer 2 frame has already been transmitted to the destination node. Even if the source port and the destination port belong to the same VLAN segment, before the layer 2 switching means 50 learns the association between the port number of the destination port and the destination MAC address in the VLAN segment. If so, flooding will occur. In this case, since the layer 2 switching means 50 forwards the layer 2 frame to all the ports in the VLAN segment, the layer 2 frame is also forwarded to the auxiliary switching means 70.

[Sequence in the operation example of the frame transfer procedure]
Finally, an operation example of the frame transfer procedure will be described. Specifically, a frame transfer procedure in the vehicle-mounted hub 20 will be described by taking as an example a layer 2 frame including vehicle-mounted information ID = IV1 (see FIG. 7).

FIG. 12 is a diagram showing a sequence in an operation example of the frame transfer procedure according to the present embodiment. As shown in FIG. 12, the layer 2 switching means 50 receives the layer 2 frame via the port 51a (S31). The layer 2 switching means 50 identifies the port number P1 of the port 51a that has received the layer 2 frame, refers to the VLAN ID table, and uses the VLAN ID = VL1 associated with the port number P1 as the source VLAN ID. get.

The layer 2 switching means 50 extracts the destination MAC address Mc from the received layer 2 frame, refers to the MAC address table, and acquires the port number P3 associated with the destination MAC address Mc. The layer 2 switching means 50 refers to the VLAN ID table, and since the port number P3 is not associated with the source VLAN ID (VLAN ID = VL1), the layer 2 switching means receives the layer 2 frame of the VLAN tag. Insert (S33). Specifically, the layer 2 switching means 50 inserts a VLAN tag including a source VLAN ID (VLAN ID = VL1) into the layer 2 header of the received layer 2 frame.

The layer 2 switching means 50 causes flooding and transfers the layer 2 frame into which the VLAN tag including the source VLAN ID (VLAN ID = VL1) is inserted to the auxiliary switching means 70 via the in-hub port 51e. (S35). The layer 2 switching means 50 subsequently transfers the received layer 2 frame to the remaining ports 51b in the VLAN segment # 1 without using the VLAN tag (S37).

Even if the node 10b connected to the port 51b receives the layer 2 frame including the vehicle-mounted information ID = IV1 due to flooding, the destination MAC address is not the MAC address Mb of the node 10b, so that the layer 2 frame is used. Discard. The processing contents from S31 to S37 correspond to the operation flow 1 of the layer 2 switching means 50 described above.

The auxiliary switching means 70 receives the layer 2 frame in which the VLAN tag including the source VLAN ID (VLAN ID = VL1) is inserted via the in-hub port 51e of the layer 2 switching means 50. The auxiliary switching means 70 extracts the vehicle-mounted information ID = IV1 from the layer 2 payload of the received layer 2 frame, and obtains the source VLAN ID (VLAN ID = VL1) from the layer 2 header of the received layer 2 frame. Extract (S39).

The auxiliary switching means 70 refers to the vehicle-mounted information ID table and identifies the destination node 10c associated with the extracted vehicle-mounted information ID = IV1. The auxiliary switching means 70 refers to the destination VLAN ID table and acquires the destination VLAN ID (VLAN ID = VL2) associated with the destination node 10c (S41).

Since the destination VLAN ID (VLAN ID = VL1) is different from the source VLAN ID (VLAN ID = VL2), the auxiliary switching means 70 replaces the VLAN tag (S43). Specifically, the auxiliary switching means 70 uses a VLAN tag including a source VLAN ID (VLAN ID = VL1) inserted in a layer 2 header of a layer 2 frame, and a destination VLAN ID (VLAN ID = VL2). Replace with a tag.

When the auxiliary switching means 70 replaces the VLAN tag, the layer 2 frame in which the VLAN tag including the destination VLAN ID (VLAN ID = VL2) is inserted is transferred to the in-hub port 51e of the layer 2 switching means 50 (the auxiliary switching means 70). S45). The processing contents from S39 to S45 correspond to the operation flow of the auxiliary switching means 70 described above.

The layer 2 switching means 50 receives the layer 2 frame in which the VLAN tag including the destination VLAN ID (VLAN ID = VL2) is inserted via the in-hub port 51e. The layer 2 switching means 50 extracts the destination VLAN ID (VLAN ID = VL2) from the layer 2 header of the received layer 2 frame (S47). The layer 2 switching means 50 selects a destination VLAN segment (VLAN segment # 2) to which a destination VALN ID (VLAN ID = VL2) is assigned (S49).

The layer 2 switching means 50 extracts the destination MAC address Mc from the received layer 2 frame, refers to the MAC address table, and acquires the port number P3 associated with the destination MAC address Mc. Since the layer 2 switching means 50 refers to the VLAN ID table and the port number P3 is associated with the destination VLAN ID (VLAN ID = VL2), the received layer 2 frame is the port having the port number P3. Transfer to 51c (S51). At this time, the layer 2 switching means 50 transfers the layer 2 frame from which the VLAN tag including the destination VLAN ID (VLAN ID = VL2) is removed to the port 51c. The processing contents from S47 to S51 correspond to the operation flow 2 of the layer 2 switching means 50 described above.

As described above, the vehicle-mounted message having the vehicle-mounted information ID = IV1 is forwarded to the ports in the VLAN segments # 1 and # 2, but not to the ports in the VLAN segment # 3. Therefore, only the highly reliable node is connected to the port belonging to the VLAN segments # 1 and # 2, and the low reliability node is connected to the port belonging to the VLAN segment # 3. It is possible to improve the security of the in-vehicle network.

[Action / Effect]
According to the present embodiment, when the layer 2 frame is not a unicast frame forwarded to a port in the source VLAN segment to which the source port belongs, the layer 2 switching means 50 relatives to the layer 2 frame. Insert the source VLAN ID. The layer 2 switching means 50 transmits the layer 2 frame in which the source VLAN ID is inserted to the auxiliary switching means 70.

The auxiliary switching means 70 refers to the vehicle-mounted information ID table and identifies the destination node associated with the vehicle-mounted information ID included in the layer 2 frame. The auxiliary switching means 70 refers to the destination VLAN ID table and acquires the destination VLAN ID associated with the identified destination node.

The auxiliary switching means 70 replaces the source VLAN ID inserted in the layer 2 frame with the acquired destination VLAN ID. When the auxiliary switching means 70 replaces the VLAN ID, the layer 2 frame is transmitted to the layer 2 switching means 50. The layer 2 switching means 50 transfers the layer 2 frame from which the destination VLAN ID has been removed to the destination port based on the destination VLAN ID included in the layer 2 frame.

With such a configuration, the vehicle-mounted hub 20 can transfer frames between VLAN segments without using an IP address. Therefore, the configuration of the in-vehicle network can be simplified. Moreover, since no IP address is used, it is not necessary to provide an expensive and complicated layer 3 switching means. Therefore, according to the present embodiment, it is possible to suppress an increase in manufacturing cost.

In the present embodiment, by setting an in-vehicle message including an in-vehicle information ID in the layer 2 payload of the layer 2 frame, the layer 2 switching means 50 and the auxiliary switching means 70 are used to transfer the frame between the VLAN segments. It can be carried out. Therefore, it is possible to effectively suppress an increase in manufacturing cost as compared with the case of using the layer 3 switching means.

Further, the frame is not transferred between the segments to the destination node that is not associated with the vehicle-mounted information ID. Therefore, according to the present embodiment, the security of the in-vehicle network can be improved.

As a result, according to the present embodiment, it is possible to provide an in-vehicle hub 20 and an in-vehicle system 1 that can improve the security of an in-vehicle network while suppressing an increase in manufacturing cost.

According to the present embodiment, when the auxiliary switching means 70 determines that the destination VLAN ID is different from the source VLAN ID, the auxiliary switching means 70 replaces the source VLAN ID inserted in the layer 2 frame with the destination VLAN ID. When the auxiliary switching means 70 replaces the VLAN ID, the layer 2 frame is transmitted to the layer 2 switching means 50.

When the destination VLAN ID is the same as the source VLAN ID, the layer 2 switching means 50 has already transferred the layer 2 frame within the VLAN segment. Therefore, with such a configuration, when the destination VLAN ID is the same as the source VLAN ID, the auxiliary switching means 70 does not transmit the layer 2 frame to the layer 2 switching means 50, so that the load on the vehicle-mounted hub 20 is applied. Can be reduced.

According to the present embodiment, when the auxiliary switching means 70 cannot extract the vehicle-mounted information ID from the layer 2 frame, the auxiliary switching means 70 discards the layer 2 frame.

With such a configuration, the vehicle-mounted hub 20 does not perform illegal layer 2 frame transfer between the VLAN segments, so that the security of the vehicle-mounted network can be improved.

According to the present embodiment, the auxiliary switching means 70 discards the layer 2 frame when the destination node associated with the vehicle-mounted information ID cannot be identified.

With such a configuration, the vehicle-mounted hub 20 does not perform illegal layer 2 frame transfer between the VLAN segments, so that the security of the vehicle-mounted network can be improved.

[Other embodiments]
In the above-described embodiment, the vehicle-mounted network is divided into three VLAN segments, but it may be divided into two VLAN segments or four or more VLAN segments.

In the above-described embodiment, the vehicle-mounted information ID = IV1 (see FIG. 7) is associated with, but is not limited to, a destination node connected to a port belonging to one VLAN segment different from the source VLAN segment. .. For example, the vehicle-mounted information ID = IV1 is associated with the destination node 10d connected to the port 51d belonging to the VLAN segment # 3 in addition to the destination node 10c connected to the port 51c belonging to the VLAN segment # 2. May be good.

In this case, the vehicle-mounted message having the vehicle-mounted information ID = IV1 is transferred to the ports in the VLAN segments # 1 to # 3. Therefore, the security of the in-vehicle network can be improved by connecting only the highly reliable nodes to the ports belonging to the VLAN segments # 1 to # 3.

Upon receiving the layer 2 frame including the vehicle-mounted information ID = IV1, the auxiliary switching means 70 acquires the destination VLAN ID = VL2 and VL3 in S25 of FIG.

Therefore, in S29 of FIG. 11, the auxiliary switching means 70 may replace the source VLAN ID with the destination VLAN ID = VL3 in the layer 2 frame including the MAC address Mc of the destination node 10c as the destination MAC address. be.

Similarly, in S29 of FIG. 11, the auxiliary switching means 70 may replace the source VLAN ID with the destination VLAN ID = VL2 in the layer 2 frame including the MAC address Md of the destination node 10d as the destination MAC address. be.

In these cases, the layer 2 switching means 50 causes flooding in the destination VLAN segment because the port number associated with the destination MAC address does not exist in the port number associated with the destination VLAN ID. Forward to all ports of.

Specifically, the layer 2 switching means 50 transmits a layer 2 frame including the MAC address Mc of the destination node 10c as the destination MAC address to the port 51d in the VLAN segment # 3. The node 10d connected to the port 51d discards the layer 2 frame because the destination MAC address of the received layer 2 frame is not the MAC address Md of the node 10d.

Similarly, the layer 2 switching means 50 transmits a layer 2 frame including the MAC address Md of the destination node 10d as the destination MAC address to the port 51c in the VLAN segment # 2. The node 10c connected to the port 51c discards the layer 2 frame because the destination MAC address of the received layer 2 frame is not the MAC address Mc of the node 10c.

In the embodiment described above, in the vehicle-mounted system 1, all the nodes are housed by one vehicle-mounted hub, but may be housed by a plurality of vehicle-mounted hubs. Even in this case, the vehicle-mounted network can be divided into a plurality of VLAN segments.

FIG. 13 is an overall schematic configuration diagram of the in-vehicle system 100 according to the modified example of the present embodiment. As shown in FIG. 10, the vehicle-mounted system 100 includes nodes 110a to 110k and vehicle-mounted hubs 120a to 120c.

The vehicle-mounted hub 120a accommodates the nodes 110a to 110d, and includes a layer 2 switching means 150a and an auxiliary switching means 170a.

The vehicle-mounted hub 120b accommodates the nodes 110e to 110h, and includes a layer 2 switching means 150b and an auxiliary switching means 170b.

The vehicle-mounted hub 120c accommodates the nodes 110i to 110k, and includes a layer 2 switching means 150c and an auxiliary switching means 170c.

In the in-vehicle system 100, the ports 151a to 151d, the ports 151f to 151i, the ports 151k and 151l, and the ports 151e and 151j in the hub belong to the VLAN segment # 10. The port 151m belongs to the VLAN segment # 20. The in-hub port 151n belongs to the VLAN segments # 10 and # 20. VLAN ID = VL10 and VLAN ID = VL20 are assigned to the VLAN segments # 10 and # 20.

The layer 2 switching means 150a has the same configuration as the layer 2 switching means 50 except for the following points. (1) The layer 2 switching means 150a is connected to the layer 2 switching means 150b via a port (not shown) and a cable 200a that belong to the VLAN segment # 10 and do not use a VLAN tag.

The layer 2 switching means 150b has the same configuration as the layer 2 switching means 50 except for the following points. (1) The layer 2 switching means 150b is connected to the layer 2 switching means 150a via a port (not shown) and a cable 200a that belong to the VLAN segment # 10 and do not use a VLAN tag. (2) The layer 2 switching means 150b is connected to the layer 2 switching means 150c via a port (not shown) and a cable 200b that belong to the VLAN segment # 10 and do not use a VLAN tag.

The layer 2 switching means 150c has the same configuration as the layer 2 switching means 50 except for the following points. (1) The layer 2 switching means 150c has three ports to which a node is connected. (2) The layer 2 switching means 150c is connected to the layer 2 switching means 150b via a port (not shown) and a cable 200b that belong to the VLAN segment # 10 and do not use a VLAN tag.

The auxiliary switching means 170a to 170c have the same configuration as the auxiliary switching means 70.

In the vehicle-mounted system 100 configured in this way, for example, consider a case where a node 110a transmits a layer 2 frame including a vehicle-mounted message to a node 110k belonging to a different VLAN segment. In this case, the auxiliary switching means 170a to 170c hold the vehicle-mounted information ID table and the destination VLAN ID table having the following information. The vehicle-mounted information ID table has information for associating the vehicle-mounted information ID included in the vehicle-mounted message with the destination node 110k. The destination VLAN ID table has information for associating the destination node 110k, the port number of the destination port 151m connected to the destination node 110k, and the VLAN ID = VL20 of the VLAN segment # 20 to which the destination port 151m belongs.

The vehicle-mounted hub 120a performs the same processing as the vehicle-mounted hub 20, and transfers the layer 2 frame to the vehicle-mounted hub 120c via the vehicle-mounted hub 120b. In the vehicle-mounted hub 120c, the layer 2 switching means 150c refers to the VLAN ID table and identifies that the destination port 151m connected to the destination node 110k does not exist among the ports in the source VLAN segment # 10. .. The layer 2 switching means 150c generates flooding and transfers the layer 2 frame in which the VLAN tag including the source VLAN ID = VL10 is inserted to the auxiliary switching means 170c.

The auxiliary switching means 170c refers to the vehicle-mounted information ID table and the destination VLAN ID table, and replaces the VLAN tag including the source VLAN ID = VL10 inserted in the layer 2 frame with the VLAN tag including the destination VLAN ID = VL20. .. The auxiliary switching means 170c transfers the layer 2 frame in which the VLAN tag including the destination VLAN ID = VL20 is inserted to the layer 2 switching means 150c.

The layer 2 switching means 150c refers to the MAC address table and the VLAN ID table, and transfers the layer 2 frame received from the auxiliary switching means 170c to the destination port 151m in the destination VLAN segment # 20. At this time, the layer 2 switching means 150c removes the VLAN tag including the destination VLAN ID = VL20 from the layer 2 frame, and transfers the layer 2 frame to the port 151m.

In a conventional in-vehicle system using layer 3 switching means, as the number of in-vehicle hubs increases, so does the number of layer 3 switching means. Therefore, the number of transfer devices increases, and the configuration of the in-vehicle network becomes complicated. On the other hand, in this modification, since the auxiliary switching means is provided in the vehicle-mounted hub, the number of transfer devices can be reduced and the configuration of the vehicle-mounted network can be simplified.

In the above-described embodiment, the layer 2 switching means 50 virtually (logically) divides the vehicle-mounted network into a plurality of segments by the VLAN, but the method of dividing the vehicle-mounted network is not limited to this. For example, the layer 2 switching means 50 may divide the vehicle-mounted network into a plurality of segments in a fixed (physical) manner without using a VLAN.

In the embodiments described above, the layer 2 frame does not include the layer 3 header, but is not limited thereto. For example, the layer 2 frame may include a layer 3 header in the layer 2 payload. In this case, the layer 3 header does not include the source IP address and the destination IP address, but includes a specific bit string.

The block configuration diagram (FIGS. 3 and 6) used in the description of the above-described embodiment shows a block of functional units. These functional blocks are realized by any combination of at least one of hardware and software. Further, the method for realizing each functional block is not particularly limited. For example, each functional block may be realized using one physically or logically coupled device, or two or more physically or logically separated devices may be directly or indirectly connected. , These may be realized by using a plurality of devices. The functional block may be realized by combining software with one device or a plurality of devices.

When each of the layer 2 switching means 50 and the auxiliary switching means 70 is composed of a plurality of hardware elements, each functional block is realized by any hardware element or a combination of the hardware elements. Hardware elements include processors, memory, storage, input devices, output devices, buses, and the like.

Further, in this case, each function of the layer 2 switching means 50 and the auxiliary switching means 70 is realized by loading predetermined software (program) on hardware such as a processor and a memory. Specifically, each function is realized by loading a predetermined software on the hardware so that the processor performs an operation and controls reading and writing of data in the memory and the storage.

Although the present embodiment has been described above, the present embodiment is not limited to these, and various modifications can be made within the scope of the gist of the present embodiment.

1,100 In-vehicle system 10a to 10d, 110a to 110k Nodes 20, 120a to 120c In-vehicle hub 50, 150a to 150c Layer 2 switching means 51a to 51d, 151a to 151d, 151f to 151i, 151k to 151m Ports 51e, 151e, 151j , 151n In-hub port 57 Layer 2 receiver 59 Layer 2 processing unit 70, 170a to 170c Auxiliary switching means 72 Auxiliary storage unit 73 Extraction unit 75 Acquisition unit 77 Frame processing unit

Claims (5)

An in-vehicle hub with multiple ports that can be configured to belong to different segments in an in-vehicle network.
Layer 2 switching means and
Auxiliary switching means connected to the layer 2 switching means and
Equipped with
The layer 2 switching means is
A layer 2 receiver that receives a frame containing the MAC address of the source node, the MAC address of the destination node, and the vehicle-mounted message including the vehicle-mounted information ID from the source port connected to the source node.
If it is determined that the frame is not a unicast frame forwarded to a port in the first segment to which the source port belongs, the first segment ID assigned to the first segment is inserted into the frame. A layer 2 processing unit that transfers the frame to the auxiliary switching means,
Equipped with
The auxiliary switching means is
Auxiliary to store information relating the vehicle-mounted information ID, the destination node to which the vehicle-mounted message is transmitted, and the second segment ID assigned to the second segment to which the destination port connected to the destination node belongs. Memory and
An extraction unit that extracts the vehicle-mounted information ID from the frame received from the layer 2 processing unit, and an extraction unit.
An acquisition unit that identifies the destination node associated with the extracted vehicle-mounted information ID based on the information and acquires the second segment ID associated with the identified destination node.
A frame processing unit that replaces the first segment ID inserted in the frame with the acquired second segment ID and transfers the frame to the layer 2 switching means.
Equipped with
The layer 2 processing unit is an in-vehicle hub that transfers the frame from which the second segment ID has been removed to the destination port based on the second segment ID included in the frame received from the frame processing unit. When the frame processing unit determines that the second segment ID is different from the first segment ID, the frame processing unit replaces the first segment ID inserted in the frame with the second segment ID, and the frame is replaced with the second segment ID. The vehicle-mounted hub according to claim 1, which is transferred to a layer 2 switching means. The vehicle-mounted hub according to claim 1 or 2, wherein when the vehicle-mounted information ID is not extracted by the extraction unit, the frame processing unit discards the frame. The vehicle-mounted hub according to claim 1 or 2, wherein when the destination node is not identified in the acquisition unit, the frame processing unit discards the frame. The in-vehicle hub according to any one of claims 1 to 4.
With a plurality of nodes housed in the in-vehicle hub,
In-vehicle system equipped with.

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