amplifier device

Abstract

A repeater usable as one of a plurality of repeaters (11-15) forming a communication network (1) together with a monitoring device (30), wherein the plurality of repeaters (11~15) each have a plurality of ports (P0~P7), wherein at least one of the plurality of ports (P0~P7) in each of the plurality of repeaters (11~15) is connected to a port of another repeater, and one of the plurality of repeaters (11~15) performs port mirroring to one of its own plurality of ports (P0~P7), wherein a mirror frame duplicated by the port mirroring is transferred to the monitoring device (30) monitoring the mirror frame, wherein the mirror frame contains a header, a type, and payload, wherein the header contains a sender media access control address, sender MAC address, wherein the repeater comprises: a first transfer unit (10a, S140~S160) configured to to add port information to the mirror frame as transfer route information, the port information being indicative of (i) one port among the plurality of ports (P0~P7) at the repeater acting as a monitoring port at which the port mirroring is performed, and (ii) another port other than the one port among the plurality of ports (P0~P7) at the repeater acting as a first destination port from which the mirror frame is output and transferred to the monitoring device (30), and output the mirror frame to which the transfer route information from the first destination port has been added, when the repeater performs port mirroring and is monitored by the monitoring device (30), and a second transfer unit (10b, S170∼S200) configured to add the port information to the mirror frame as the transfer route information, wherein the port information is indicative of (iii) one port among the plurality of ports (P0~P7) of the repeater at which the mirror frame is received from the other repeater, and (iv) another port, different from the one port, among the plurality of ports (P0~P7) at the repeater acting as a subsequent destination port from which the received mirror frame is output and transferred to the monitoring device (30), and output the received mirror frame to which the transfer route information has been added from the subsequent destination port, if the repeater does not perform port mirroring and is not monitored by the monitoring device (30).

Description

[0001] The present invention generally relates to a repeater or amplifier device that is part of a communications network.

[0002] JP 2013-192128 A describes a network switch in a communication network that functions as a repeater device, that is, a device for receiving a communication frame (i.e., frame) and transmitting the received frame (i.e., forwarding / retransmitting the received frame). The repeater device described in JP 2013-192128 A is one of a plurality of repeater devices constituting a communication network, in which the repeater device can mirror a frame (i.e., duplicate a frame) using a port mirror function and transmit the frame to a monitoring device via one or more repeater devices in the communication network.

[0003] A mirror frame is a frame that is mirrored (i.e., duplicated) by the port mirroring function of one of a plurality of repeater devices in the network and transmitted via another repeater device or devices in the network to a monitoring device that monitors the mirror frame. Such a monitoring scheme may be called remote monitoring. A port that performs port mirroring and is monitored by the monitoring device is referred to as a monitoring port. A device connected to the monitoring port that transmits a source frame mirrored by the port mirroring function of the monitoring port is referred to as a mirror source device.

[0004] However, problems with remote monitoring in a communication network may occur because it is difficult for the monitoring device to identify the mirror source device based on the mirror frame.

[0005] For example, if a monitoring port of a repeater device receives a source frame from an image source device, and either (a) the repeater device transmits a frame different from the source frame to the monitoring device from a port different from its monitoring port, or (b) another repeater device transmits a frame from a different image source to the monitoring device, the monitoring devices may confuse the frames, making it impossible for the monitoring device to identify the source device of the image frame. Consequently, repeater devices are a subject for improvement.

[0006] GB 2 333 429 A discloses a repeater usable as one of a plurality of repeaters forming a communication network together with a monitoring device, the plurality of repeaters each having a plurality of ports, at least one of the plurality of ports in each of the plurality of repeaters being connected to a port of another repeater, and one of the plurality of repeaters performing port mirroring on one of its own plurality of ports, in which a mirror frame duplicated by the port mirroring is transferred to the monitoring device monitoring the mirror frame, the mirror frame containing a header, a type, and payload, the header containing a sender address, the repeater comprising: a transfer unit configured to add port information to the mirror frame as transfer route information and to transfer the mirror frame,to which the transfer route information has been added, both when the repeater performs port mirroring and is monitored by the monitoring device, and when the repeater does not perform port mirroring.

[0007] US 2002 / 0075809 A1 discloses a network monitoring system with a monitoring device connected to a network switch via a mirror port. The network switch supports a number of regular ports connected to various network components and the mirror port connected to a monitoring device.

[0008] The mirror port mirrors all network traffic from all selected regular ports of the network switch. When the monitoring device receives a data packet from the network switch, it extracts network address information such as the source and destination addresses from the data packet. The monitoring device then checks internal lookup tables to determine if there are any corresponding physical ports for the network address information. If the corresponding physical ports are not available in the lookup table, the monitoring device queries the network switch for the corresponding physical port. The network address information is temporarily stored in a first-in, first-out buffer until the network switch responds to the monitoring device's request. Finally, the monitoring device uses the physical port to perform further network analysis functions.

[0009] US 2013 / 0 054 828 A1 discloses an information processing device having a processor for executing a process comprising: blocking communication of a request transmitted from a first device and addressed to a second device, the communication being from a network device arranged on a communication path between the first device and the second device to the second device, and / or communication of a response transmitted from the second device and addressed to the first device due to remote control via a network; detecting the request transmitted from the first device and addressed to the second device from the network device; and transmitting an instruction to switch a transmission destination of the request to a third device to the first device.

[0010] It is an object of the present disclosure to provide a repeater or amplifier device that enables an image source device to be easily identified based on an image frame. This object is achieved by a repeater having the features of claim 1. The dependent claims are directed to advantageous developments of the invention.

[0011] At least one of a plurality of ports (P0 to P7) of each of a plurality of repeaters (11 to 15) in a communications network (1) is connected to a port of another repeater device. When a repeater device of one of the plurality of repeaters in the communications network uses one of its own ports from its plurality of ports to perform port mirroring, a frame is duplicated by the port mirroring, that is, a mirror frame is transmitted from the repeater device performing port mirroring to a monitoring device (30) via one or more other repeater devices in the communications network.

[0012] In one aspect of the present disclosure, the repeater device can be used as a relay or retransmission device in the communication network described above, and the communication network can be formed by a plurality of repeater devices of the present disclosure (ie, the communication network is formed by a plurality of repeater devices). The repeater device according to one aspect of the present disclosure includes a first transfer unit (10a, S140 to S160) and a second transfer unit (10b, S170 to S200).

[0013] When a subject repeater device performs port mirroring, the first transfer unit adds (i) information about a monitor port at the subject relay device performing port mirroring and (ii) information about a first destination port at the subject repeater device as transmission route information to the mirror frame. The first destination port at the subject repeater device is the port from which the mirror frame is output for transmission to the monitor device. The first transfer unit outputs the mirror frame having the added transmission route information from the first destination port.

[0014] Upon receiving a mirror frame from another repeater device, the second transfer unit adds to the transmission route information in the mirror frame: (iii) information concerning the port receiving the mirror frame and (iv) information concerning a subsequent destination port that outputs the mirror frame to the monitoring device. The second transfer unit outputs the mirror frame with the added transmission route information from the subsequent destination port.

[0015] Using the repeater device configured as described above, the monitoring device receiving the mirror frame can identify which port of which repeater device is the monitoring port based on the transmission path information included in the mirror frame. Then, upon identifying the monitoring port, the monitoring device can identify the image source device connected to the monitoring port.

[0016] The reference numerals in parentheses in this section and in the claims indicate a correspondence between the claim elements and the components / configurations in the embodiments and are not intended to limit the scope of the present disclosure.

[0017] Objects, features and advantages of the present disclosure will become apparent from the following detailed description made with reference to the accompanying drawings. Fig. 1 illustrates a configuration of a communication network using a repeater device as a switch. Fig. 2 is a flowchart of a port mirroring process. Fig. 3 shows a frame configuration and operating effects through the switch.

[0018] An embodiment of the present disclosure will be described in the following paragraphs with reference to the drawings. [1. Configuration]

[0019] In relation to Fig. 1, a communication network 1 of the present embodiment is shown. The communication network 1 may be an Ethernet network installed in a vehicle, such as a passenger car (not shown), in which the communication network 1 is part of a communication system in the vehicle. An Ethernet network may be a network operating the following Ethernet standards and protocols, for example, IEEE802.3.

[0020] As it is in Fig. 1, the communication network 1 includes Ethernet switches 11, 12, 13, 14, and 15 (collectively referred to as switches 11-15 or 11 to 15). The switches 11-15 are Ethernet network switches that function as repeaters. The switches 11-15 can generally be referred to as repeaters or repeater devices. A repeater or repeater device can receive a communication frame and output the communication frame (i.e., forward or retransmit the communication frame). That is, the communication network 1 includes a plurality of repeaters or repeater devices 11-15, i.e., switches 11-15. As shown in Fig. 1 and Fig. 2, each switch can be abbreviated as “SW.” While the communication network 1 in Fig. 1 is a non-limiting example showing five switches 11-15, the number of switches in the network may be greater than five or less than five.

[0021] The switch 11 is included in an electronic control unit (ECU) 20, which is part of the communication network 1. ECU is an abbreviation for "electronic control unit." The communication network 1 also includes ECUs 21, 22, 23, 24, 25, and 26 as devices that communicate with each other via one or more of the switches 11 to 15.

[0022] For example, switches 11 to 15 are Layer 2 switches (i.e., "L2 switches") that communicate and forward (i.e., retransmit) data according to the Ethernet standard (i.e., IEEE802.3). Each of switches 11 to 15 has a plurality of ports. For example, each of switches 11 to 15 may have eight ports P0, P1, P2, P4, P5, P6, and P7, as shown in Fig. 1 is shown.

[0023] The ECU 21 is connected to the P2 terminal of the switch 11 via a communication line 41. The ECU 22 is connected to the P7 terminal of the switch 12 via a communication line 42. The ECU 23 is connected to the P7 terminal of the switch 14 via a communication line 43. The ECU 24 is connected to the P5 terminal of the switch 14 via a communication line 44. The ECU 25 is connected to the P4 terminal of the switch 15 via a communication line 45. The ECU 26 is connected to the P4 terminal of the switch 13 via a communication line 46.

[0024] Terminal P6 of switch 11 and terminal P1 of switch 12 are connected via a communication line 47. Terminal P6 of switch 12 and terminal P1 of switch 14 are connected via a communication line 48. Terminal P5 of switch 12 and terminal P1 of switch 15 are connected via a communication line 49. Terminal P5 of switch 11 and terminal P1 of switch 13 are connected via a communication line 50.

[0025] The electronic control units (ECUs) 20-26 are embedded systems in the vehicle that control one or more electrical systems or subsystems in the vehicle. For example, the ECUs 20-26 may be used to control the vehicle's internal combustion engine, powertrain, transmission, brakes, and suspension. Although not explicitly shown in the drawings, each of the ECUs 20-26 may include a microcontroller / microcomputer including a CPU or similar processing devices, memory such as SRAM, EEPROM, and flash memory, input / output (I / O) circuitry, and communication circuitry.

[0026] A microcomputer 10 is included as an arithmetic unit in the ECU 20. The microcomputer 10 is connected to the P0 terminal of the switch 11. In this way, the microcomputer 10 of the ECU 20 can communicate with the ECU 21 via the switch 11. The microcomputer 10 is also capable of communicating with the other ECUs 22-26 via the switch 11 and one or more of the other switches 12 to 15. Although not shown, each of the ECUs 21 to 26 also includes a microcomputer as an arithmetic unit. The microcomputer 10 includes a CPU, a ROM, a RAM, and an I / O circuit.

[0027] The microcomputer 10 may also comprise a first transfer unit 10a (ie “First XFER” in Fig. 1) and a second transfer unit 10b (ie “Second XFER” in Fig. 1). Depending on the function and purpose of the switch, the first transfer unit 10a can execute and perform specific processes, which are described in more detail below. Depending on the function of the switch and its purpose, the second transfer unit 10b can execute and perform specific processes, which are described in more detail below, in which the processes executed and performed by the first transfer unit 10a differ from the specific processes executed and performed by the second transfer unit 10b.

[0028] The ECUs 20-25 can also be considered as repeaters or amplifiers. For example, as shown in Fig. 1, the ECU 20 comprising the microcomputer 10 including the first transfer unit 10a and the second transfer unit 10b, and the switch can be considered a repeater or amplifier device, even since the switch (i.e., amplifier) ​​11 itself performs the transmission and retransmission functions of generated and received communication frames. That is, the amplifier device comprises a microcomputer 10 with a first transfer unit 10a and a second transfer unit 10b, and a switch (i.e., switch 11).

[0029] A monitoring device 30 for monitoring traffic in the communication network 1 is detachably connected to the P1 terminal of the switch 11 via a communication line 51. [2nd trial]

[0030] In relation to Fig. 1 and Fig. 2, the port mirroring process performed by each switch 11 to 15 is described.

[0031] In the following description, a description of a switch without a reference symbol can describe any of the switches 11 to 15 unless otherwise indicated. This means that a description of a switch can refer to all of the switches 11 to 15 unless otherwise indicated. Similarly, a description of a terminal without a reference symbol can refer to any of the terminals P0 to P7 unless otherwise indicated. This means that a description of a terminal can be applied to all of the terminals P0 to P7 unless otherwise indicated.

[0032] A "subject switch" may be used to describe a single switch itself, to differentiate the subject switch from the plurality of other switches when describing a plurality of switches.

[0033] A switch that performs port mirroring can be called an "implemented mirror switch" or more simply "a mirror switch." A frame duplicated by port mirroring can be called a "mirror frame."

[0034] A port that performs port mirroring may be called a monitor port. Mirroring a frame received by the monitor port of a subject switch from another switch may be called "receive mirroring." Mirroring a frame transmitted by the monitor port of the subject switch to another switch may be called "transmit mirroring." A switch that forwards / retransmits the mirror frame transmitted by the mirror switch to the monitor device 30 may be called a "mirror transfer switch."

[0035] A further distinction can be made among the plurality of ports of the subject switch. That is, a single switch may have one port of the switch designated as the "send port" and one port on the switch designated as the "destination port." The designation of the send port and destination port can best be understood from the perspective of the switch itself. When a switch receives a communication frame, the send port may be the input port, which then "sends" or forwards the communication frame to a destination port on the same switch. The "destination" on the switch is the port on the subject switch at which the frame is output for further transmission and / or processing on the communication network 1.The designation of ports on the subject switch is not always static, that is, the transmit port and destination port designations for the subject switch may change depending on the circumstances (i.e., the function of the switch, the type of frame to be processed by the switch, and which ports P0 to P7 serve as inputs and outputs to the subject switch).

[0036] For the mirror switch described above, the transmit port may be the monitor port, and the target port may be the port from which the mirror frame, when duplicated by the subject switch itself, is output to the monitor 30.

[0037] For the mirror transfer switch described above, the transmitting port may be an input port on the subject switch that inputs a mirror frame transmitted by another switch, and the destination port is an output port on the subject switch that outputs the mirror frame transmitted by the other switch for transfer to the monitoring device 30. In other words, for the mirror transfer switch, the transmitting port inputs the mirror frame from another switch, and the destination port outputs the mirror frame from the other switch.

[0038] As described in more detail below, because the mirror switch may perform processing prior to the mirror transfer switch, the destination port at the mirror switch may be designated as "a first destination port," while the destination ports at the mirror transfer switch or switch may be referred to as "subsequent destination ports" to further distinguish between the various destination ports. In other words, in a communication stream having a plurality of switches, the first destination port may refer to the destination port at the switch at which the frame is first output in the communication stream, and the subsequent destination ports may refer to the destination ports of the switches downstream of the first destination port.

[0039] The designation of a switch in the communication network 1 to act as either a mirror switch or a mirror transfer switch is not static and can change based on circumstances. For example, for one mirror frame, a switch may be designated as a mirror switch, but for another mirror frame, the same switch may be designated as a mirror transfer switch. In one example, switch 12 may receive a communication frame from ECU 22 at port P7, and the switch may be set to perform port mirroring to mirror the received frame and generate a mirror frame. In this example, switch 12 acts as a mirror switch. However, in another example, switch 12 may receive a mirror frame from switch 14 at port P6 and output the mirror frame at port P1 for further transmission downstream.In this example, switch 12 acts as a mirror transfer switch.

[0040] Each of the switches 11 to 15 can be set to function either as a mirror switch or as a mirror transfer switch. In the communication network 1, when the above-described remote monitoring is performed, one of the switches 12 to 15 is set as a mirror switch, and one or more of them on the mirror frame transfer route from the mirror switch to the monitoring device 30 are set as the mirror transfer switches. As such, when the remote monitoring is performed with the configuration described in Fig. 1, the switch is set up at least as a mirror transfer switch. For the switches in the communication network 1 that function as either the mirror switch or the mirror transfer switch or multiple thereof, one of the ports among the ports P0 to P7 on each switch is designated as the transmit port, and another of the ports on each switch is designated as the destination port. A switch that is not set up as a mirror switch and two of its eight ports are set respectively as the transmit port and the destination port may function as a mirror transfer switch. For the switch that functions as the mirror switch, the port mirroring performed by the mirror switch may further be designated as either receive mirroring or transmit mirroring.Setting the mirror switch on either receive mirrors or transmit mirrors can be referred to as input / output (I / O) setting.

[0041] Either a setting operation or sending individual setting signals to each of the switches 11 to 15 can be used to designate the switches 11 to 15 as either a mirror switch or a mirror transfer switch, or multiple thereof, to designate which terminals on the switch function as the transmitting terminal and the target terminal, and to set the I / O setting for the mirror switch. The settings of each switch can also be implemented, for example, by signals sent from the microcomputer 10. That is, the microcomputer 10 can determine whether a switch in the communication network 1 functions as the mirror switch or the mirror transfer switch.

[0042] The processes described in S110 to S210 by Fig. 2 are described as generally performed by the switches (i.e., switches 11 to 15). However, the processes may be performed by the microcomputer 10 in conjunction with the switch (i.e., the microcomputer executing a program or instructions set to control the switch to perform the functions). Certain processes may be performed by dedicated hardware or circuitry such as the first transfer unit 10a or the second transfer unit 10b (i.e., the first transfer unit 10a controls the switch to perform the specific functions).

[0043] When a switch receives a frame from one of the ports P0 to P7, the switch performs the process described in Fig. 2. As shown in Fig. 2, the subject switch (i.e., the switch receiving the frame) determines in step S110 whether the switch itself will function as a mirror switch. That is, the subject switch determines whether it will perform a mirror function or a mirror transfer function. If the subject switch determines that it will function as a mirror switch, that is, "YES" at S110, the process proceeds to S120.

[0044] In S120, the switch forwards (i.e., retransmits) the received frame as a normal frame to its intended destination. This means that the subject switch performs a normal forwarding process. Here, "normal" can mean in accordance with the Ethernet standard.

[0045] Now on Fig. 3, as it appears in the first row of Fig. As shown in Figure 3 (i.e., the top row), the normal frame contains an Ethernet header, a type, Ethernet payload, and a block check sequence field. A source MAC address field (i.e., a sender MAC address) is stored at the end of the Ethernet header. MAC stands for "Media Access Control." The Ethernet payload is a body of data transmitted in the frame. FCS, or BPF, stands for "Frame Check Sequence."

[0046] Returning to Fig. 2, after the switch performs the forwarding process of S120, the process proceeds to S130. At S130, the subject switch determines whether port mirroring is performed. Specifically, if the I / O setting is receive mirroring and a frame is received through the transmit port, the subject switch determines that port mirroring should be performed. Alternatively, if the I / O setting is transmit mirroring and the received frame is transmitted through the transmit port (i.e., to a destination port on the subject switch), the subject switch determines that port mirroring should be performed.

[0047] If the switch at S130 determines that port mirroring should not be performed, that is, “NO” at S130, the switch terminates the process that is described in Fig. 2 without performing any further processes. However, if the switch at S130 determines that port mirroring should be performed, i.e., "YES" in S130, the process proceeds to S140.

[0048] The processes at S140, S150, and S160 (ie, S140 to S160) are associated with a port mirror function and are performed by the switch. The port mirror processes at S140 to S160 can also be performed by a microcomputer 10 in conjunction with the switch, or can be performed by the first transfer unit 10a in conjunction with the switch.

[0049] At S140, if the I / O setting is receive mirroring, the switch generates a mirror frame by duplicating a frame received at the transmit port (i.e., monitor port). Alternatively, at S140, if the I / O setting is transmit mirroring, the switch generates a mirror frame by duplicating a frame transmitted from the transmit port. If the I / O setting is transmit mirroring, the mirror frame at S140 can be generated by duplicating a received frame, since the frame transmitted from the transmit port is the same as the received frame.

[0050] At S140, the switch adds a field to the generated mirror frame, which is called a unique field. The mirror frame to which the unique field is added is called a remote mirror frame.

[0051] Again in relation to Fig. 3, the remote mirror frame contains a unique field added at a position between the Ethernet header and the type field. More specifically, the unique field is located at a position between the source MAC address field and the type field. The unique field includes a first area where an identification code or similar identification device is stored, and a second area where mirror source information is stored.

[0052] The identification code stored in the first area of ​​the unique field is a code that identifies the frame containing the unique field as a mirror frame. The mirror source information stored in the second area of ​​the unique field is used by the monitoring device 30 to identify the mirror source device.

[0053] The mirror source information includes (i) a hop counter value representing the number of switches that the mirror frame has passed through remotely (i.e., the number of “hops”), (ii) I / O information indicating the I / O setting contents, and (iii) information indicating the destination port and the transmit port of the switch that transmitted the mirror frame remotely. Fig. 3. "I" in an I / O information line indicates that the I / O setting is receive mirroring. "O" in the I / O information column indicates that the I / O setting is transmit mirroring.

[0054] Again in relation to Fig. 2 At S140, the switch generates a mirror frame (ie a mirror frame from afar), to which a unique field is added and the process continues with S150. At S150, as shown in a row (A) in Fig. 3, the switch introduces (i) information indicating a transmission port (hereinafter referred to as transmission port information) and (ii) information indicating a destination port (hereinafter referred to as destination port information) in a preset order to the second field of the unique field. The transmission port information and the destination port information may be collectively referred to as "transfer route information." That is, transfer route information includes both transmission port information and destination port information, and the transfer route information may include all of the transmission port information and destination port information in the unique field. In the present embodiment, the transmission port information is introduced after the destination port information.At S150, the switch introduces EOF, which indicates that one end of the unique field is at a position after the transmit port information. EOF stands for "End Of Field." In the present embodiment, the transmit port information and destination port information are port numbers, meaning that one number corresponds to one of the ports P0-P7. As shown in row (A) of FIG. Fig. 3, the transmitting terminal information is “7” (ie, P7 of the subject switch) and the destination terminal information is “1” (ie, P1 of the subject switch).

[0055] At S150, the switch also inserts the above-described identification code into the first portion of the unique field and inserts the hop count and I / O information before the destination port information. The hop count introduced at S150 is 1, which is the initial or starting count.

[0056] At S160, the switch transmits the mirror frame from the target port after performing the process at S150 and the process performed in Fig. 2 is shown, then ends.

[0057] When the processes at S140-S160 are performed by the first transfer unit 10a at the switch, the first transfer unit 10a adds information about the monitoring port at the subject switch that performs port mirroring (ie, information about the transmit port) and information about the target port at the subject switch to the mirror frame. That is, the first transfer unit 10a adds the transfer route information of the mirror switch to the mirror frame. The first transfer unit 10a then outputs the mirror frame having the added transfer route information from the target port of the subject switch.

[0058] Returning to S110, when the switch determines at S110 that the switch itself is not set as the mirror switch, that is, “NO” at S110, the process proceeds to S170.

[0059] The processes at S170, S180, S190, and S200 (ie, S170-S200) are performed by the switch when the subject switch does not function as a mirror switch. As such, the processes at S170-S200 can be performed by the switch, the microcomputer 10 in conjunction with the switch, or the second transfer unit 10b in conjunction with the switch.

[0060] At S170, the switch determines whether a frame has been received through the switch's transmit port. If the switch determines that a frame has been received through the switch's transmit port, i.e., "YES" at S170, the process proceeds to S180. If the switch determines that a frame has been received through the switch's transmit port and the process proceeds from S170 to S180, the switch is set as an image transfer switch. This means that the switch is designated as an image transfer switch.

[0061] At S180, the switch determines whether a unique field is inserted in the received frame, i.e., whether the frame was received by the transmit port. For example, as described above, the switch may determine that a unique field is inserted if there is an identification code at a position after the Ethernet header, or more specifically, after the source MAC address field.

[0062] If the switch determines at S180 that a unique field is introduced in the received frame, i.e., "YES" at S180, the switch determines that the received frame is a mirror frame and the process continues with S190. At S190, as shown in row (B) or row (C) in Fig. 3, the switch introduces the transmit port information indicating the port of the switch that acts as the transmit port, and the destination port information in a preset order at a position immediately after the I / O information in the second area of ​​the unique field. Fig. 3, the position at which this information is inserted is referred to as "additionally inserted." In the present embodiment, as in S150, the transmit port information is inserted after the destination port information. The switch also implements the hop count in the unique field of the received mirror frame at S190.

[0063] After S190, the process continues with S200 and the switch transmits the mirror frame from the target port. After S200, the process ends, which is Fig. 2 is shown.

[0064] When the processes at S170-S200 are performed by the second transfer unit 10b at the switch, the second transfer unit 10b adds information concerning the port of the subject switch that receives the mirror frame (transmission port information) and information concerning the destination port of the subject switch that outputs the mirror frame either to the monitoring device 30 or for further transmission toward the monitoring device 30. That is, the second transfer unit 10b adds the transfer route information of the subject mirror transfer switch to the mirror frame. The second transfer unit 10b then outputs the mirror frame having the added transfer route information from the destination port of the subject switch.

[0065] Returning to S170, if the switch at S170 determines that a frame has not been received by the transmit port, or if the transmit port is not set, that is, "NO" at S170, the process proceeds to S210.

[0066] If the switch determines at S180 that a unique field is not introduced in the received frame, the process also continues with S210.

[0067] At S210, the switch forwards (retransmits) the received frame as a normal frame similar to the process performed at S120, and the process performed at Fig. 2 is shown, ends.

[0068] The process that Fig. 2 can be implemented by one or more hardware devices provided with the switch. For example, the one or more hardware devices used in the process shown in Fig. 2, can be implemented as a digital circuit or digital circuit elements, an analog circuit or analog circuit elements, or as a combination of digital / analog circuits and circuit elements. The first transfer unit 10a and the second transfer unit 10b can be implemented as specialized hardware within a switch. That is, the first transfer unit 10a can be configured as a specialized circuit for performing the processes at S140 to S160. For example, the first transfer unit 10a can be implemented as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a similar specialized circuit configured to perform the processes at S140 to S160. Similarly, the second transfer unit 10b can be configured as a specialized circuit for performing the processes at S170 to S200.As described above, the switch may contain a microcomputer and perform the processes at . Fig. 2 can alternatively be carried out by the microcomputer either completely or partially. If the microcomputer 10 at the switch performs all of the processes described in Fig. 2 (ie, S110-S210), the first transfer unit 10a and the second transfer unit 10b can be considered as functional blocks of the microcomputer 10 rather than as individual hardware elements. The microcomputer in the switch has a CPU and a semiconductor memory (hereinafter, a memory) such as RAM and / or ROM. Some or all of the processes (ie, S110-S200) performed by the switch in Fig. 2 can be realized by execution by the CPU of a program / instruction set stored in the memory of the switch. The execution of such a program / instruction set can cause the switch to perform all or part of the processes that are Fig. 2. The memory is a non-volatile, tangible storage medium of the microcomputer configured to store a program / instruction set for execution by the CPU. The memory described above may be a non-volatile, tangible storage medium for storing a program. [3. Example company]

[0069] An example operation example shown by switches 11 to 15, which control the process that is Fig. 2, is now described. The example operation is described with respect to the communication network 1 of Fig. 1, which assumes an example situation in which a frame is transmitted from the ECU 23 connected to the switch 14 and in which the transmitted frame is monitored by the monitoring device 30.

[0070] In this example, the settings for each of switches 11 through 15 can be preset. Switch 14 is configured as a mirror switch with an I / O setting set to receive mirrors. Both switches 11 and 12 are configured as mirror transfer switches.

[0071] In the switch 14, the terminal P7 connecting the ECU 23 is set as a transmitting terminal and the terminal P1 connecting the switch 12 is set as the target terminal.

[0072] In the switch 12, the terminal P6 connected to the terminal P1 of the switch 14 is set as the transmitting terminal and the terminal P1 connected to the switch 11 is set as the destination terminal.

[0073] In the switch 11, the terminal P6 connected to the terminal P1 of the switch 12 is set as the transmitting terminal, and the terminal P1 connected to the monitoring device 30 is set as the destination terminal.

[0074] That is, the mirror frame generated by the port mirror function of the switch 14 is set to be transmitted to the monitoring device 30 via the switch 12 and the switch 11.

[0075] The example operation also assumes that the ECU 23 transmits a frame addressed to the ECU 24 when the settings described above are made. Upon receiving a frame from the ECU 23, the switch 14 determines that the switch 14 itself functions as a mirror switch, i.e., "YES" at S110 of Fig. 2, and the switch 14 transmits the frame (ie, a normal frame) received from the ECU 23 for transfer to the ECU 24 from the terminal P5 of the switch 14. The retransmission or forwarding of the frame as a normal frame corresponds to the process at S120 of Fig. 2.

[0076] In Fig. 1, a solid line arrow Y1 indicates the forwarding or retransmission of a normal frame from the ECU 23 to the ECU 24 via the switch 14.

[0077] The switch 14, which receives the frame from the ECU 23, determines that a port mirroring should be performed, that is, “YES” at S130 in Fig. 2. So switch 14 designates port P7 as the transmit port and sets the I / O setting to receive mirrors.

[0078] When performing port mirroring, which is similar to the processes of S140 and S150 at Fig. 2, the switch 14 duplicates the frame received through the terminal P7, adds a unique field to the duplicated frame and generates a remote mirror frame as shown in Fig. 3 is shown.

[0079] In the unique field of the remote mirror frame, as shown in row (A) of Fig. As shown in Fig. 3, a number corresponding to the port P7 (ie, 7) of the switch 14 is introduced as the transmit port information, and a number corresponding to the port P1 (ie, 1) of the switch 14 is introduced as the destination port information. "1" is also introduced as the hop count in the unique field.

[0080] The switch 14 then carries out the process at S160 from Fig. 2 and transmits the generated remote mirror frame from port 1, which is set as the destination port.

[0081] The remote mirror frame transmitted from the terminal P1 of the switch 14 is input to the terminal P6 of the switch 12. Upon receiving the remote mirror frame, the switch 12 executes the process at S110 of Fig. 2. Upon receiving the remote mirror frame, the switch 12 determines that the switch itself does not function as a mirror switch, that is, makes a “NO” determination at S110 of Fig. 2. As described above, since the terminal P6 of the switch 12 is designated as the transmission terminal, the switch 12 determines that the frame transmitted by the switch 14 is received by the transmission terminal P6 of the switch 12, that is, “Yes” at S170 of Fig. 2. In addition, as described above, since the switch 14 adds a unique field to the remote mirror frame, the switch 12 determines that the received frame contains a unique field, that is, “YES” at S180 of Fig. 2. That is, the switch 12 determines that a remote mirror frame with a unique field is received by the transmit port P6 of the switch 12.

[0082] The switch 12 then carries out the process at S190 from Fig. 2 and introduces the transmit port information and the destination port information of the switch 12 at the unique field of the remote mirror frame as shown in row (B) of Fig. 3. As shown in row (B) of Fig. 3, the transmit and destination port information of switch 12 can be inserted at a position before the transmit and destination port information introduced by switch 14. Switch 12 implements the hop count value in the unique field. Thus, the hop count value shown in row (B) of Fig. 3 is shown, from “1” to “2”.

[0083] That is, the switch 12 introduces a number corresponding to the transmitting port P6 (ie, 6) as the transmitting port information at the unique field of the far mirror frame, introduces a number corresponding to the destination port P1 (ie, 1) as the destination port information at the unique field of the far mirror frame, and implements the hop count value to "2".

[0084] The switch 12 then carries out the process at S200 from Fig. 2 and transmits the remote mirror frame from the destination port P1 after adding information to the unique field.

[0085] The remote mirror frame transmitted from the destination terminal P1 of the switch 12 is input to the transmit terminal P6 of the switch 11. After receiving the remote mirror frame, the switch 11 then performs the same operations previously performed by the switch 12, that is, the processes at S110, S170, S180, S190, and S200 at Fig. 2. Thus, the switch 11 adds information to the unique field of the remote mirror frame at S190. The switch 11 adds a number corresponding to the transmitting port P6 (ie, 6) of the switch 11 as the transmitting port information and adds a number corresponding to the destination port P1 (ie, 1) of the switch 11 as the destination port information, as shown in row (C) of Fig. 3. Switch 11 also implements the hop count value of the unique field to "3", as shown in row (C).

[0086] The switch 11 then carries out the process at S200 from Fig. 2 and transmits the remote mirror frame from the target port P1. The remote mirror frame transmitted from the target port P1 of the switch 11 is input to the monitoring device 30.

[0087] In Fig. 1, a dotted arrow Y2 indicates a transfer of a remote mirror frame from the switch 14 to the monitoring device 30 via the switch 12 and the switch 11.

[0088] By referring to the remote mirror frame, the monitoring device 30 can identify that the ECU 23 is the mirror source device from the unique field of the mirror source frame. That is, the monitoring device 30 is able to identify the mirror source device 23 by referring to the mirror source information in the remote mirror frame.

[0089] An example of a normal frame being forwarded (i.e., retransmitted) without port mirroring will now be described. This example assumes that the ECU 24 transmits a frame addressed to the ECU 22. Upon receiving the frame from the ECU 24, the switch 14 transmits the received frame from the port P1 as a normal frame for transfer to the ECU 22, which is based on the process at S120 of Fig. 2 follows, but the switch 14 determines that the port mirroring is not performed, that is, “NO” at S130 of Fig. 2.

[0090] Thus, switch 12 receives the frame from the transmit port P6, but the received frame is a normal frame without a unique field. If switch 12 performs the processes at S170 and S180 at Fig. 2, switch 12 determines that the frame is received by the transmitting port P6, that is, "YES" at S170, but switch 12 determines that the frame does not have a unique field, that is, "NO" at S180. So the process continues at Fig. 2 proceeds to S210 and the switch 12 transmits the received frame from the terminal P7 to transmit the frame to the ECU 22.

[0091] The two-short-stroke-one-long-stroke arrow Y3, which Fig. 1 shows the transmission of a normal frame from the ECU 24 via the switch 14 and the switch 12 to the ECU 22 or the forwarding thereof. [4. Effects]

[0092] The following advantageous effects can be realized by using the embodiment described above.

[0093] The monitoring device 30 is capable of identifying the mirror source device by referring to the mirror source information in the remote mirror frame. More specifically, the monitoring device can identify the mirror source by referring to the transmit port information and the destination port information sequentially added by each of the switches that transmitted the remote mirror frame. That is, using the above-described embodiment, it is possible to identify which port of which switch is the monitoring port based on the sequentially added transmit port information and the destination port information.Among the transmission port information added to the unique field, the newest or oldest transmission port information in the unique field, that is, the transmission port information immediately before the EOF, indicates the monitor port. If the monitor port can be identified, the device connected to the monitor port can be identified as the image source device. In the example operation described above, the ECU 23 can be identified as an image source device.

[0094] A switch performing port mirroring adds a unique field to a preset position in the mirror frame and stores the transmit port information and the destination port information as transfer route information in the added unique field. Afterward, when a mirror frame is received from another switch, each switch stores (or adds) its own transmit port information and destination port information as transfer route information in the unique field of the mirror frame. This makes it possible to add additional transfer route information to the original frame without affecting other information in the original frame.

[0095] The unique field is a field provided at a position between the source MAC address field and the type field in an Ethernet frame. It allows transfer route information to be added without affecting the Ethernet protocol.

[0096] Each switch determines whether the received frame is a mirror frame or not based on whether the received frame has a unique field. This makes it easy to determine whether the received frame is a mirror frame.

[0097] The unique field of a frame contains an identification code that allows the frame to be identified as a mirror frame. This allows each switch to correctly determine whether the received frame is a mirror frame based on the identification code. [5. Other embodiments]

[0098] Although one embodiment has been described above, the present disclosure is not limited to the above-described embodiment, and various modifications may be made.

[0099] For example, if communication network 1 determines that network traffic at one or more of the switches (e.g., 11-15) is excessive, network 1 may stop the transfer of a low-priority frame, and such a frame may be dropped. In such a case, the priority of the mirror frame may be set to a second-from-top priority or lower. This means that network 1 may be configured to control the priority of the mirror frame to control or alleviate network congestion.

[0100] The communication protocol used by Network 1 may be different from the Ethernet protocol. The hop count or I / O information may also not be included in a mirror frame. The transfer route information may be added to a predefined position in the Ethernet payload field.

Claims

[1] Repeater, which can be used as one of a plurality of repeaters (11-15) which together with a monitoring device (30) form a communication network (1), wherein the plurality of repeaters (11-15) each has a plurality of ports (P0-P7), wherein at least one of the plurality of ports (P0-P7) on each of the plurality of repeaters (11-15) is connected to a port of another repeater, and one of the plurality of repeaters (11-15) performs port mirroring to one of its own plurality of ports (P0-P7), wherein a mirror frame duplicated by the port mirroring is transferred to the monitoring device (30) which monitors the mirror frame, wherein the mirror frame contains a header, a type and payload, wherein the header contains a sender media access control address, sender MAC address, and wherein the repeater has: a first transfer unit (10a, S140~S160) that is configured to to add port information to the mirror frame as transfer route information, wherein the port information indicates (i) a port among the plurality of ports (P0~P7) at the repeater, which acts as a monitoring port where port mirroring is performed, and (ii) another port, different from the one, among the plurality of ports (P0~P7) at the repeater, which acts as a first destination port from which the mirror frame is output and transferred to the monitoring device (30), and to output the mirror frame to which the transfer route information from the first destination port has been added, when the repeater performs connection mirroring and is monitored by the monitoring device (30), and a second transfer unit (10b, S170~S200) that is configured to to add the connection information to the mirror frame as the transfer route information, wherein the connection information is indicating (iii) a port among the plurality of ports (P0~P7) of the repeater at which the mirror frame is received from the other repeater, and (iv) another port, different from the one, among the plurality of ports (P0~P7) at the repeater, which acts as a subsequent destination port from which the received mirror frame is output and transferred to the monitoring device (30), and to output the received mirror frame, to which the transfer route information has been added, from the subsequent destination port, if the repeater does not perform connection mirroring and is not monitored by the monitoring device (30). [2] Repeater according to claim 1, wherein the first transfer unit (10a, S140~S160) is also configured to add a unique field at a preset position at the mirror frame and to store the transfer route information at the unique field, and the second transfer unit (10b, S170-S200) is also configured to receive the mirror frame and store the transfer route information in the unique field of the received mirror frame. [3] Repeater according to claim 1 or 2, wherein the repeater is configured for use in a network that uses an Ethernet standard and wherein the unique field located at a position between a source MAC address field and a type field in an Ethernet frame. [4] Repeater according to claim 2 or 3, wherein the second transfer unit (10b, S170-S200) is further configured to determine whether the received frame is a mirror frame or not, based on whether the unique field is present in the received frame or not (S180). [5] Repeater according to claim 4, wherein the unique field contains an identification code that identifies a frame having the unique field with the identification code as the mirror frame.

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