JP2003198549A - Network system and test method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a network system in which a learning function of a destination address in a bridge can be tested and processing of a packet length in the bridge and the storage capacity or aging of a memory for storing a destination address can be tested as well. <P>SOLUTION: The network system is equipped with an optical conversion repeater RE provided between a wide area LAN and an optical fiber transmission line FB for electrically/optically converting and transferring a data frame and an optical conversion bridge BR provided between a user LAN and the optical fiber transmission line FB for electrically/optically converting and transferring the data frame under medium access control and in the optical conversion repeater RE, a control packet for controlling the loop-back test of the optical conversion bridge BR and a test packet for the loop-back test are generated and transmitted through the optical fiber transmission line FB to the optical conversion bridge BR. At the same time, the system has a control part 14 for performing different loop-back tests by connecting a measurer for generating the other test packet in place of the wide area LAN. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network system and a test method thereof, and more particularly to a loopback test method for a LAN-to-LAN connection system that transmits, for example, an Ethernet (registered trademark) frame.

[0002]

2. Description of the Related Art In recent years, wide area LANs have been constructed in each area based on LAN (local area network) technology, and a communication network in which these are connected by a high-speed broadband backbone network has been deployed nationwide and put into practical use. It is being implemented. An optical fiber is applied as the transmission line base, and so-called FTTO (fiber to the offic) is used.
e) or a network service (optical broadband connection service) called FTTH (fiber to the home) that extends to user connection has come to be provided.

An OSI (open systems interconnectio) is used as a LAN connecting device for connecting LANs.
n) A repeater that connects at the physical layer level of the model,
Known are bridges that connect at the data link layer level, routers that connect at the network layer level, and gateways that connect at a higher level than the transport layer. In particular, bridge-type LAN-to-LAN connections are connected via a common data link layer, so
P / IP (transmission control protocol / internet p
It is possible to connect LANs with each other by an inexpensive device regardless of a higher-level protocol such as rotocol.

Therefore, as a network configuration for connecting the user LAN to the wide area LAN of the communication carrier at low cost, a bridge type LAN connecting device is installed in the user's house and the repeater type LAN connecting device is provided to the communication company. Is installed and both are connected by an optical fiber transmission line. In this case, the telecommunications carrier's responsibility demarcation point is located at the terminating point (physical layer device in the bridge) inside the optical fiber transmission line, and maintenance and monitoring functions up to that terminating point are required. A back test was performed on this endpoint.

[0005]

In the above-mentioned conventional loopback test, a predetermined test packet generated by a repeater of a telecommunications carrier is repeatedly transmitted at a predetermined interval so that a bridge device in a user's house can be used. The test packet returned at the electrical physical layer termination unit (physical layer device) with the user LAN is detected, and whether the looped back test packet matches the transmitted test packet is compared to determine whether it is normal or abnormal. Was being judged.

However, in the conventional loopback test, the address learning function and the address aging function are remotely confirmed with respect to the MAC switch mounted in the bridge device (or bridge) and transferring the data frame according to the MAC address. It has the drawback of not being able to. That is, in the loopback test, the test of the address learning function is to create a source address with a repeater, send a test packet with this source address attached to the bridge, and use this source address as the destination address. Store in address memory.

Then, the repeater transmits a test packet having the source address as the destination address to the bridge. As a result, it is confirmed that the test packet having the same destination address as the destination address stored in the address memory is discarded by the MAC switch and is not looped back. However, in the conventional test method, the repeater performing the test can output the destination address only as a fixed address such as a broadcast address, so that the destination address stored in the address memory and the destination address of the test packet cannot be compared. Since it cannot be performed, there is a problem that the learning test cannot be performed on the destination address because the content of the address memory is unknown.

Further, since the repeater used for general purpose does not have the function of changing the source address,
Multiple test packets with different source addresses,
Cannot be generated. Therefore, in the conventional test method, the more the destination addresses corresponding to the capacity of the address memory of the MAC switch are stored, the more the destination addresses cannot be stored in the address memory that stores the destination addresses.
Since the above-described learning test cannot be performed on the entire address memory, there is a drawback in that it cannot be tested whether or not all the memory elements of the capacitors are operating normally.

Further, in the conventional test method, since the test packet has a fixed length and a fixed pattern and the transmission interval is constant, the test packet having a random packet length and a random pattern is looped. There is also a drawback that a stricter loopback test cannot be performed by backing up or adjusting the transmission amount of the test packet. In addition, in the conventional test method,
A test packet with a fixed-pattern source address attached is sent periodically (for example, several hundred msec), so a loopback test with a certain period cannot be performed, and a predetermined period (for example, several minutes) is not possible. There is a drawback that the aging function that resets the contents of the address memory cannot be tested.

The present invention has been made under such a background, and the test of the learning function of the destination address in the bridge can be performed, the processing of the packet length in the bridge and the storage capacity and aging of the memory for storing the destination address can be performed. The purpose is to provide a network system that can also be tested.

[0011]

A network system of the present invention connects a user LAN (user LAN / LU) and a wide area LAN (carrier network LC) of a communication carrier with an optical fiber transmission line (optical fiber transmission line FB). A wide area LAN, which is a network system connected via
A first optical conversion device (optical conversion repeater RE), which is provided between the optical fiber transmission line and the optical fiber transmission line and electrically / optically converts a data frame to be transmitted, and the user LAN and the optical fiber transmission line. And a second optical conversion device (optical conversion bridge BR) which is provided between the optical conversion units and electrically / optically converts the transmitted data frame and transfers the data frame by medium access control. The device
A control packet for controlling a loopback test with the second optical conversion device and a test packet used for the loopback test and having the same configuration as the data frame are generated, and are generated via the optical fiber transmission line. A test control means for performing a different loopback test by connecting a measuring device (measuring device M) that transmits another test packet to the second optical conversion device instead of the wide area LAN ( A control unit 14), wherein the second optical conversion device sets the physical layer termination point with the user LAN to a loopback test state based on the control packet from the first optical conversion device, It is characterized by having a loop control means (control unit 6) for performing a loopback process of each of the test packets received via the optical fiber transmission line.

In the network system of the present invention, the first optical conversion device has an electrical physical layer terminating unit (PHY-E · 17) connected to a wide area LAN and an optical physical layer connected to an optical fiber transmission line. A control packet from the terminating unit (PHY-O · 11) and the test control means is transmitted to the second optical conversion device via the optical physical layer terminating unit, and the second packet for the control packet is transmitted. Control packet insertion detection unit (control packet insertion detection unit 12) for detecting a response packet from the optical conversion device, and a test packet from the test control unit are transmitted to the second optical conversion device, Test packet insertion detection means (test packet insertion detection unit 1 for detecting a test packet looped back from the optical conversion device of FIG.
5), and a data switching unit (data switching unit 25) for controlling permission / non-permission of packet transfer from the optical physical layer termination unit to the electrical physical layer termination unit based on the control by the test control unit. It is characterized by having.

In the network system according to the present invention, the test control means includes a start packet for starting a loopback test,
Packet generating means for respectively generating a control packet including an end packet and a test packet, and a packet detecting means for detecting a response packet to the start packet, a response packet to the end packet, and a test packet to be looped back. Packet comparison means for comparing whether or not the test packet to be looped back and the transmitted test packet match, notification means for notifying the comparison result of the comparison means to the outside, the response packet, looped back Data switching notifying means for stopping the transmission of the test packet to the wide area LAN side.

In the network system of the present invention, the second optical conversion device is connected to the user LAN,
An optical physical layer termination unit for performing packet transfer processing in the physical layer and an optical physical layer termination unit for performing packet transfer processing in the physical layer between the optical fiber transmission line, and the electrical physical layer termination unit and optical physical layer The first switch is provided between the MAC switch and the optical physical layer terminating unit, which is provided between the terminating units and transfers the packet according to the MAC address included in each packet. Control packet insertion detection means (control packet insertion detection means) for detecting and supplying the control packet from the optical conversion device to the loop control means and transferring the response packet from the loop control means to the first optical conversion device. Means 3) are included.

In the network system of the present invention, the loop control means detects the control packet including the start packet and the end packet from the first optical conversion device, and the packet detection means starts the packet. When a packet or an end packet is detected, a packet generation means for generating a response packet for each packet, and when an activation packet is detected by the packet detection means, the electro-physical layer termination unit is set to a loopback state, and the end A loop setting releasing means for releasing the loopback state when receiving a packet, and a MAC when receiving the start packet and the end packet
And a reset means for resetting the switch.

The network system test method of the present invention is a test method for performing a loopback test of a packet in the above-mentioned network system, wherein the start packet for instructing the loopback test is sent from the first optical conversion device. In the process of transmitting to the second optical conversion device via the optical fiber transmission line, and in the second optical conversion device receiving the activation packet, the electro-physical layer termination unit with the user LAN is set to the loopback state. Corresponding to the activation packet and the activation packet,
A step of transmitting a response packet in response to the optical conversion device of 1 to the first optical conversion device via the optical fiber transmission line;
In the first optical conversion device that has received the response packet,
A test packet with the same structure as the predetermined data frame
In the process of being transmitted to the second optical conversion device via the optical fiber transmission line, and in the second optical conversion device receiving the test packet, the test packet is terminated at the electrical physical layer termination unit with the user LAN. The process of looping back and looping back again to the first optical conversion device via the optical fiber transmission line and the looped back test packet received in the first optical conversion device and the transmitted test packet match. The process of comparing whether or not the result of the comparison, the process of notifying the result of the comparison to the outside, and the measuring device according to the comparison result.
Connecting to the electrical physical layer termination of the optical converter of
A process in which an arbitrary test packet transmitted from the measuring device is transmitted to the second optical conversion device via an optical fiber transmission line, and a test packet received in the second optical conversion device, Based on the process of looping back at the end of the physical layer of the user LAN and looping back to the first optical conversion device via the optical fiber transmission line, and the test packet received by the measuring device, A loopback test is performed on the second light conversion device.

According to the network system testing method of the present invention, in the second optical conversion device, the MAC switch is reset when the electrical physical layer termination unit with the user LAN is set to the loopback state based on the start packet. It is characterized by

In the network system test method of the present invention, when the loopback test is completed in the first optical conversion device, an end packet is transmitted to the second optical conversion device via the optical fiber transmission line. A process, a process of canceling the loopback setting of the electrical physical layer termination unit with the user LAN based on the received end packet in the second optical conversion device, and a response packet corresponding to the end packet. A process of transmitting from the second optical conversion device to the first optical conversion device via an optical fiber transmission line and returning to a normal data communicable state, and the response packet in the first optical conversion device. And a step of returning to a normal data communicable state based on the reception of.

According to the network system test method of the present invention, in the second optical conversion device, when the end packet is received and the loopback setting of the electric physical layer termination unit with the user LAN is released, the MAC switch is reset. It is characterized by

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of a network system according to an embodiment of the present invention. The inter-LAN connection system (network system) of FIG. 1 is a carrier network L such as a wide area LAN of a telecommunications carrier via a user LAN via an optical fiber transmission line FB.
It is a user / network interface of a subscriber access system connected to C, and includes an optical fiber transmission line FB, an optical conversion repeater RE connected to the station side thereof, and an optical conversion bridge BR connected to the inside of the home. There is.

In particular, the feature of this embodiment is that the optical conversion repeater RE on the station side is connected to the optical conversion bridge BR on the inside of the home via the optical fiber transmission line FB and Ethernet (registered trademark).
A start packet shorter than the packet length of the frame is supplied, and a test packet having a fixed packet length and fixed pattern similar to that of the Ethernet (registered trademark) frame is transmitted to perform a remote loopback test. The optical conversion repeater RE has a test function for transmitting a test packet sent from the measuring instrument M connected to the electrical interface (electrical physical layer termination unit) and performing a remote loopback test by applying a loopback test method unique to the present application. That is.

In this embodiment, the user LAN / LU is a 10Base-T or 100Base-T to which data terminals such as a plurality of personal computers are connected.
It is an Ethernet (registered trademark) LAN of T, and is connected to a carrier network LC of a wide area LAN by a network system (inter-LAN connection system) of the present invention. This user LAN / LU is, for example, a router R
It is connected to the optical conversion bridge BR via T, a hub, or the like. On the other hand, a carrier network L that is a wide area LAN
C is, for example, an Ethernet (registered trademark) -based high-speed broadband LAN having a transmission band of several Gbps, accommodating a plurality of user LANs for each region, and 100 Gbp.
WAN (wid that connects to each area through s-class backbone network)
e area network). The carrier network LC is connected to the optical conversion repeater RE via a router RK or an L2 switch, for example.

The routers RT and RK are switches at the network layer level, and for example, IP (Int) in an Ethernet (registered trademark) frame transmitted in this embodiment.
ernet protocol) L that distributes routes according to addresses
It is an inter-AN connection device. As shown in FIG. 2, the Ethernet (registered trademark) frame has a preamble PA indicating a synchronization signal and an 8-bit frame start delimiter SFD.
And the destination MAC (media acces
s control) address DA, source MAC address SA representing source address, length type LT representing data length or data type, variable length transmission data DT including IP header, destination MAC address DA to data DT Pad PAD that is added when the length up to is less than 64 octets and is adjusted to the length of 64 octets
And a frame check sequence F for detecting an error of a frame such as a CRC (cyclic redundancy check) code.
And CS. The LAN-to-LAN connection system according to the present embodiment is a bridge that transfers each Ethernet (registered trademark) frame based on an Ethernet (registered trademark) header including a destination MAC address DA, a source MAC address SA, and a length type LT. Method LAN
It is an inter-connection system.

Next, a configuration example of the network system according to the embodiment will be described in detail with reference to FIG. The optical conversion repeater RE (first optical conversion device) is installed on the telecommunications carrier side, and is an Ethernet (registered trademark) frame transferred from the router RK through an electric transmission line such as a twisted pair line (twisted pair), And Ethernet (registered trademark) frames from the user LAN / LU transferred via the optical fiber transmission line FB are converted into electric / optical signals and transferred to each other.
The optical conversion repeater RE includes a PHY-E 17 (electrical physical layer terminating unit), a test packet insertion detecting unit 15, a control packet insertion detecting unit 12, a data switching unit 25, and a PHY-.
It has an O.11 (optical physical layer termination unit), a remote loop switch unit 19, and a control unit 14.

The PHY-E 17 is a layer 1 (physical layer) terminating circuit that terminates an Ethernet (registered trademark) frame transmitted to and received from the router RK, and has a physical layer device and 10Base-T. Or 100Base-
A T connector and a transformer are provided for matching between the connector and the physical layer device. Further, the physical layer device is a device that performs processing such as waveform shaping of an Ethernet (registered trademark) frame. PHY-O
11 is a layer 1 that terminates an Ethernet (registered trademark) frame transmitted to and received from the optical fiber transmission line FB
And a line interface with an optical fiber transmission line FB including an electric / optical conversion circuit, and a physical layer device that performs processing such as waveform shaping of an Ethernet (registered trademark) frame converted into an electric signal. is doing. PH
The YO-11 and the PHY-E-17 are respectively connected to the outgoing route 2 through the series connection of the control packet insertion detection unit 12, the test packet insertion detection unit 15, and the data switching unit 25.
0, connected by the return line 21.

The test packet insertion detector 15 inserts the test packet generated by the controller 14 into the outgoing line 20 and transmits it to the optical fiber transmission line FB during the loopback test of the remote loop. Looped back,
The test packet input (received) from the optical fiber transmission line FB is taken into the control unit 14 from the return route 21.
In addition, the test packet insertion detection unit 15 is configured as PHY-E.
It was installed on the outgoing line 20 from 7 to PHY-O.11.
The switch SW 16 is a changeover switch, and the detection line 22 commonly connected to the return line 21. This switch SW-1
The switch 6 switches whether the switching SW 13 is connected to the PHY-E 17 (normal mode) or is connected to the control unit 14 (loopback mode).

The control packet insertion detection unit 12 inserts the control packet generated by the control unit 14 into the outgoing line 20 and transmits it to the optical fiber transmission line FB at the time of the loopback test of the remote loop. The response packet from the optical conversion bridge BR installed at is detected from the return route 21. In addition, the control packet insertion detection unit 12 is provided with a changeover switch, which is a changeover switch, provided on the outgoing route 20.
3 and the detection line 23 commonly connected to the return line 21. The switching SW 13 connects the PHY-O 11 to the control unit 14 (loopback mode) or the switching SW 13
The connection with 16 (normal mode) is switched.

The data switching unit 25 responds to the control packet transmitted from the control packet insertion detection unit 12 during the loopback test of the remote loop, that is, the response packet transmitted from the optical conversion bridge BR in the user's house. Control packet and the looped back test packet are controlled to be transferred to the PHY-E17. In addition, the data switching unit 25 includes PHY-O / 11 and P.
It has a changeover SW 24 which is a changeover switch and is interposed between the HY-E 17 and the HY-E 17.

The remote loop SW section 19 is a section for instructing the control section 14 to start and end the loopback test of the remote loop by using a test switch. In this embodiment, the test switch is pressed. By this, it will be in the ON state and the loopback test will be started.
A control signal for ending the loopback test is output to the control unit 14.

The control section 14 mainly controls each section of the optical conversion repeater RE during the loopback test of the remote loop, and presses down the test switch or controls from a remote control device (not shown) to perform the loopback test. To execute. The result of this loopback test is multiple LEDs
In the LED (light emitting diode) unit 18 configured by, the notification is given by turning on the LED corresponding to the processing result or by notifying the remote control device.

Here, referring to FIG. 4, the optical conversion repeater R
The control unit 14 in E will be described. FIG. 4 shows the control unit 14.
A block diagram showing a configuration example of the above is shown. In this figure, the switch detection unit 35 detects ON / OFF of the test switch during the loopback test of the remote loop,
This detection result is used as the packet generation unit 32 and the timer setting unit 3
3, LED control unit 36, and PHY-O → PHY-E
The data is output to the transfer control unit 34. Packet generator 3
2 generates a control packet including an activation packet and an end packet for controlling the optical conversion bridge BR to be in a mode corresponding to the loopback test, and a test packet used for the loopback test.

Further, the packet generator 32 generates each packet in a predetermined order according to the timing signal from the switch detector 35, the timer setting unit 33, and the control signal from the packet detector 30. Here, the test packet is generated in the same format (configuration) as the Ethernet (registered trademark) frame shown in FIG. 2, a broadcast address representing the broadcast is given as its destination MAC address DA, and a source MAC address SA is given. The address of the own device is given, and as data DT, for example, 64 by repeating “11001100” or the like.
A data pattern of te is added. In addition, the test packet is transmitted up to 16 times at a predetermined interval in this embodiment, although it depends on the setting.

On the other hand, the control packet is formed to have a shorter packet length than the Ethernet (registered trademark) frame, and is given a broadcast address representing broadcast as the destination MAC address DA as shown in FIG. 2, for example.
The address of the own device is given as the source MAC address SA, and, for example, the activation packet is "0" as the data DT.
A 4-byte data pattern is provided by repeating "001", and a 4-byte pattern is provided by repeating the packet "0011". In the present embodiment, the start packet and the end packet are transmitted up to four times at a predetermined interval, depending on the setting.

Returning to FIG. 4, the timer setting unit 33 supplies the packet generation unit 32 with the transmission timing of the start packet, the end packet, and the test packet, and the transmission timeout time, and the start ACK packet in the packet detection unit 30. And a timer circuit for setting the reception timeout time of the end ACK packet (time to detect an abnormality if the response to the packet transmitted during this period is not returned) and the reception timeout time of the test packet in the packet comparison unit 31. The LED control unit 36 controls the lighting of the LED unit 18 (FIG. 3) during the loopback test, and activates A which is a response to the activation packet from the optical conversion bridge BR.
When the reception of the CK packet is detected, the yellow LED indicating that the test is in progress is turned on in the LED section 18.

Further, when the packet comparison unit 31 determines that the test packet is normally received, the LED control unit 36 determines that, for example, 16 test packets generated and output by the packet generation unit 32 are packet packets. When all are normally detected by the comparison unit, the LED unit 18 displays the green LE according to the notification from the packet comparison unit 31.
Turn on D. On the other hand, the LED control unit 36 causes the packet detection unit 30 to activate the start ACK packet and the end ACK.
When the packet is not normally received or when the test packet is not normally received by the packet comparison unit 31, the red LED indicating the abnormality is turned on in the LED unit 18. Then, when the loopback test ends, that is, the LED control unit 36, that is, the packet detection unit 3
At 0, when the end ACK packet is normally received, all the LEDs of the LED unit 18 are turned off.

The packet detection unit 30 is an optical conversion bridge B installed in the user's home during the loopback test.
The start ACK packet and the end ACK packet responded from R, and the test packet output from the packet generation unit 32 and looped back from the optical conversion bridge BR are detected. Further, the packet detection unit 30 sends the detection result of the activation ACK packet to the packet generation unit 32 and the LED control unit 3.
6, and the timer setting unit 33, and the detection result of the end ACK packet is detected by the timer setting unit 33 and the LED control unit 3.
6, and PHY-O → PHY-E transfer control unit 34 is notified, and the detected test packet is transferred to the packet comparison unit 31.

The packet detection unit 30 receives the activation AC received.
It is determined whether the K packet and the end ACK packet have a preset data pattern, and when the activation ACK packet has the preset pattern, the LED
A control signal for turning on the yellow LED indicating that the activation ACK packet is normally received is output to the control unit 36. Also, the packet detection unit 30 normally activates the activation ACK to the LED control unit 36 when the activation ACK packet and the termination packet do not have a preset pattern.
A control signal for turning on the red LED indicating that the packet and the end ACK packet cannot be received is output.

The packet detecting section 30 includes a timer setting section 33.
, A signal notifying a time-out period from when the start packet and the end packet being timed by the timer setting unit are transmitted to the reception of the start ACK packet and the end ACK packet is received, and the start ACK packet to be responded is received. Even when the end ACK packet and the end ACK packet are not detected within the timeout time, the LED control unit 36 is normally activated by the start ACK packet and the end AC.
A control signal for turning on the red LED indicating that the K packet cannot be received is output. The packet detector 30
When outputting the control signal for turning on the red LED to the LED control unit 36, that is, when the activation ACK packet and the termination ACK packet cannot be received normally, P
SW-2 for the HY-O → PHY-E transfer control unit 34
A control signal for turning ON 4 is output. Similarly, when the end ACK packet is normally received, PHY-O → P
The HY-E transfer control unit 34 is notified of a signal for turning on the SW · 24.

The packet comparison unit 31 is the packet generation unit 3
2 compares the pattern of the test packet sent from 2 and the pattern of the test packet looped back from the optical conversion bridge BR, and counts the number of received loopback test packets. To do.
When the comparison results match, the packet comparison unit 31 counts the number of times of reception of the matched test packet with an internal counter, and when the counted value is the same as the number of transmitted test packets, For example, when the number of received packets is 16 and the number of matched test packets is 16, the LED control unit 36 and the remote control device are notified of a signal indicating that the test result is normal.
The packet comparison unit 31 performs a time-out from when the 16th test packet is transmitted from the packet generation unit 32, which is timed by the timer setting unit 33, until the 16th test packet is detected. If a signal notifying time is received and 16 test packets cannot be received by this timeout time, L
A signal indicating that the test result is abnormal is notified to the ED control unit 36 and the remote control device.

Further, when the test result is judged, the packet comparison unit 31 irrespective of whether the test result is normal or abnormal, the PHY-O → PHY-E transfer control unit 34.
Output a control signal to switch the switch SW-24 to the ON state,
That is, PHY-O.11 notifies PHY-E.17 of cancellation of the data transmission stop. PHY-O → PH
During the loopback test, the Y-E transfer control unit 34 receives the signal indicating the start or the end of the loopback test from the switch detection unit 35, so that the PHY-O.
In order to stop the data transmission from 1 to PHY-E · 17, the control signal to be turned off is output to the switching SW 24,
Activation A transmitted from the optical conversion bridge BR in the user's house
The CK packet, the end ACK packet, and the test packet output by the packet generation unit 32 and looped back are prevented from being transferred to the PHY-E · 17. Further, the PHY-O → PHY-E transfer control unit 34 follows the PHY-O.11 to P control in response to the data transmission stop release notification from the packet comparison unit 31 or packet detection unit 30.
In order to restore the data transmission to the HY-E.17, the control signal for turning it on is output to the switching SW.24.

Returning to FIG. 3, the optical conversion bridge BR is installed in the user's house and is the user LAN. An Ethernet (registered trademark) frame from the router RT of the LU and an Ethernet (registered trademark) frame from the carrier network LC transferred through the optical fiber transmission line FB are attached to each Ethernet (registered trademark) frame. It is a MAC bridge that transfers to a mutual LAN according to an address. The optical conversion bridge BR performs electric / optical conversion of an Ethernet (registered trademark) frame between the electric transmission line such as a twisted pair from the router RT and the optical fiber transmission line FB, and performs medium access control. Optical conversion bridge B
R is PHY-O.5 (optical physical layer termination unit), control packet insertion detection unit 3, MAC switch 2, and PHY-E.
-1 (electrical physical layer termination unit) and a control unit 6 are included.

PHY-O.5 is an optical fiber transmission line FB
Ethernet (registered trademark) for sending and receiving to and from
It is a layer 1 termination circuit that terminates the frame, and
It has a line interface with an optical fiber transmission line FB including an optical conversion circuit, and a physical layer device for performing processing such as waveform shaping of an Ethernet (registered trademark) frame converted into an electric signal. Here, the physical layer device is connected to the MAC switch 2 by the outward route 8 and the backward route 9 via the control packet insertion detection unit 3.

The control packet insertion detector 3 detects the start packet from the optical conversion repeater RE installed in the station from the outgoing line 8 during the loopback test of the remote loop. Further, the control packet insertion detection unit 3 inserts the start ACK packet and the end ACK packet generated by the control unit 6 on the return route 9. Control bucket insertion detector 3
Is the detection line 10 commonly connected to the outward route from the optical physical layer termination unit 5 to the MAC switch 2, and the MAC switch 2 and P
It has a changeover switch SW4, which is a changeover switch, which is inserted on the return line 9 between the HY-O5 and the HY-O5. The MAC switch 2 uses the Ethernet (registered trademark) according to the MAC address attached to the Ethernet (registered trademark) frame.
Transfer processing to transfer frames, user LAN
-10Base-T and 100B depending on the LU bandwidth
switching of ase-T. This MAC switch 2
Is connected to PHY-E.1 by an outbound route 8 and a return route 9.

The PHY-E.1 is a layer 1 termination circuit that terminates an Ethernet (registered trademark) frame transmitted to and received from the router RT, and has a physical layer device.
It has a 10/100 Base-T connector and a transformer for matching between the connector and the physical layer device. Further, the physical layer device is a device that performs processing such as waveform shaping of an Ethernet (registered trademark) frame. In particular, the physical layer device in PHY-E.1 has a loopback that forms a loopback path so that the test packet is not sent to the outside (router RT, etc.) under the control of the control unit 6 during the loopback test. Have a mode.

The control unit 6 controls the PHY-E.multidot. During the loopback test from the optical conversion repeater RE installed in the station.
Controls whether or not the loopback mode is set for 1. Further, the control unit 6 executes the loopback control in the loopback test by receiving the activation packet from the optical conversion repeater RE, and turns on or blinks the LED 7 to perform the loopback test. Notify outside that there is. Further, the control unit 6 receives the end packet from the optical conversion repeater RE, executes the end process of the loopback control in the loopback test, turns off the LED 7 or stops the blinking, and The outside is notified that the back test is completed.

Next, the control unit 6 in FIG. 3 will be described in detail with reference to FIG. FIG. 5 is a block diagram showing a configuration example of the control unit 6. In this figure, the packet detector 5
The packet generator 6 outputs a start detection signal indicating that the input of the start packet has been detected when detecting that, for example, three continuously input start packets each match a predetermined data pattern. 54, timer setting unit 55, MAC switch setting unit 53, PHY setting unit 51,
Output to the LED control unit 52. Also, the packet detector 5
The packet generator 6 outputs an end detection signal indicating that the input of end packets has been detected, when it is detected that, for example, three end packets that are continuously input each match a predetermined data pattern. 54, timer setting unit 55, MAC switch setting unit 53, PHY setting unit 51,
Output to the LED control unit 52.

The PHY setting unit 51 starts the loopback test, that is, the start detection signal indicating that the start packet is detected is input from the packet detection unit 56, so that the physical layer in the PHY-E-1 is Set the device to full-duplex mode and loopback mode.
Further, the PHY setting unit 51 receives the end detection signal indicating that the end packet has been detected at the end of the loopback test, that is, from the packet detection unit 56, so that the physical layer device in PHY-E. Return from the loopback mode in the loopback test to the normal mode.

The MAC switch setting unit 53 resets the MAC switch 2 when the activation detection signal is input from the packet detection unit 56 and a timeout signal (described later) is not input from the timer setting unit 55, and the MAC switch setting unit 53 resets the MAC switch 2. Clear the address table and set the communication mode to full-duplex mode. On the other hand, the MAC switch setting unit 53
When the end detection signal is input from the packet detection unit 56, the MAC switch 2 is reset, its address table is cleared again, and the loopback mode is returned to the normal mode.

The packet generation unit 54 includes a packet detection unit 5
By inputting the start detection signal from 6, the start ACK packet to be returned is generated corresponding to this start packet. Further, the packet generation unit 54 receives the end detection signal from the packet detection unit 56, and thus generates an end ACK packet to be returned in response to this end packet. Here, the packet generation unit 54 generates each packet according to the timing signal from the timer setting unit 55 or the instruction from the packet detection unit 56.

The activation ACK packet is formed to have a shorter packet length than the Ethernet (registered trademark) frame,
As shown in FIG. 2, the destination MAC address DA is given a broadcast address representing broadcast, the source MAC address SA is given the address of the own device, and the data DT is a 4-byte pattern formed by repeating “0010”, for example. Granted. Similarly, the end ACK packet is formed to have a packet length shorter than that of the Ethernet (registered trademark) frame, and as shown in FIG. 2, a broadcast address representing the broadcast is added as the destination MAC address DA, and the source MAC address. The address of the own device is given as SA, and the data DT
For example, 4 bytes by repeating “0100”
Pattern is added. The start ACK packet and the end ACK packet differ depending on the setting based on the timing output from the timer setting unit 55 at a predetermined interval, corresponding to the start packet and the end packet.
It is sent out once.

Returning to FIG. 5, the timer setting unit 55 receives the activation packet or the termination packet, and after a certain period of time, the timer setting unit 55 instructs the packet generation unit 54 to activate the activation ACK packet or the termination ACK. Supplies a packet transmission timing signal. That is, when the start detection signal or the end detection signal is input, the packet generation unit 54 responds to the input of these detection signals, respectively, and corresponding to the above-mentioned timing signals, a total of four start ACKs.
The packet or the end ACK packet is transmitted to the optical conversion repeater via the switching SW-4.

Further, the timer setting circuit 55 detects each not only the start detection signal and the end detection signal but also the first and third start packets and end packets from the packet detection unit 56. When the detection signal is input and the set predetermined time is exceeded from the detection of the first activation packet (or end packet) to the detection of the third activation packet (or end packet), the PHY setting unit 51 and A time-out signal is supplied to the MAC switch setting unit 53. The LED control unit 52 controls lighting and blinking of the LED 7 according to each detection signal from the packet detection unit 56. That is, the LED control unit 52 lights up the LED 7 which is a yellow LED indicating that the test is in progress by receiving the start detection signal from the packet detection unit 56, and receives the end detection signal to input the LED 7. Turn off.

Next, an operation example of one embodiment will be described with reference to FIGS. 3, 4, 5 and 6. FIG. 6 is a conceptual diagram showing a test sequence of a loopback test in the network system of this embodiment. <Start of loopback test> When starting the loopback test in the remote loop, the telecommunications carrier side tests the remote loop SW-19 of the optical conversion repeater RE or the remote loop SW-19 via the remote control device. The switch is turned on (step S1). As a result, in the optical conversion repeater RE, the control unit 14 detects that the test switch is in the ON state,
The switching SW 24 is set to the loopback mode (step S2).

Next, the control unit 14 switches the input destination of the switching SW 13 to the loopback mode, that is, the start packet generated by the control unit 14 is set to the switching SW 13 instead of the packet from the switching SW 16. Through the optical conversion bridge BR via the optical transmission bridge BR (step S
3). At this time, four start-up packets are generated at predetermined intervals and are sequentially supplied to the optical conversion bridge BR via the PHY-O.11 and the optical fiber transmission line FB (step S4).

Next, the control unit 6 determines whether or not three activation packets have been received without any abnormality. At this time, the activation packet is also supplied from the outward route 8 to the MAC switch 2, but the MAC switch 2 discards it because its data length is shorter than a normal frame, and the downstream side, that is, the PH.
Do not transfer to Y-E.1. Then, the control unit 6 determines whether or not the first activation packet is received, and when the first activation packet is detected, the timer setting unit 55 starts time counting. Here, the timer setting unit 55 determines whether or not a predetermined time T1 considering the inter-packet gap (interval of each activation packet), that is, the time that the third activation packet should reach.

At this time, the timer setting section 55 sets the time T1.
If has not elapsed, it is determined whether or not the third activation packet has been received. Then, the timer setting unit 55 does not receive the detection signal of the third activation packet, and the predetermined time T
When 1 has passed, the timer is cleared. As a result, the optical conversion bridge BR does not transmit the activation ACK packet to the optical conversion repeater RE. On the other hand, when the timer setting unit 55 receives the activation packet for the third time and confirms that the time T1 has not elapsed, the control unit 6 resets the MAC switch 2 and sets it to full duplex, and PHY-. E
• Set the physical layer device 1 to full-duplex and loopback mode.

Next, the control unit 6 turns on the yellow LED 7 to notify the outside that the loopback test of the remote loop is being performed (step S5). Next, the control unit 6 sets the switching SW-4 in the loopback mode, generates the activation ACK packet, and transmits the activation ACK packet to the optical conversion repeater RE four times (step S6). As a result, the activation ACK packet is transmitted from the switching SW-4 of the control packet insertion detection unit 3 to the PH
It is transmitted to the optical conversion repeater RE via YO-5 and the optical fiber transmission line FB. And the optical conversion repeater R
At E, the PHY-O.11 converts the activation ACK packet into an electrical signal, and the activation ACK packet is detected by the detection line 23.
It is taken into the control unit 14 via.

The switching SW 24 discards the activation ACK packet and does not transfer it to the PHY-E 17. And
When the activation ACK packet is input, the control unit 14 receives the activation packet from the optical conversion bridge and then activates the AC.
The timer setting unit 33 determines whether or not a predetermined time T2 considering the time required to transmit the K packet has passed, that is, whether or not the time at which the third activation ACK packet should arrive has passed. At this time, if the time T2 has not elapsed, the control unit 14 determines whether or not the third activation ACK packet has been received. Then, the control unit 14 clears the timer of the timer setting unit 33 when the predetermined time T2 elapses without receiving the third activation ACK packet.
The red LED in the LED section 18 lights up to notify the outside that the remote loop test cannot be started.

On the other hand, the control section 14 sends the third activation ACK.
If a packet has been received and time T2 has not elapsed,
The switching SW-13 is set to the normal mode (step S7), and the switching SW-16 is set to the loopback mode (step S7).
8). Next, the control unit 14 lights up the yellow LED in the LED unit 8 to notify the outside that the loopback test of the remote loop is being performed. Then, the control unit 14 causes the timer setting unit 55 to start time counting,
The reception counter indicating the reception of the test packet is cleared, the test packet is generated and transmitted, and the loopback test is performed. Here, as described above, in the timer setting unit 33, the transmission timeout time of the test packet is set in advance to a time required to transmit the test packet, for example, 16 times, and the timeout time is set. Until the time elapses, the packet generator 32 continues to generate and output the test packet. Then, the control unit 14
Stops the transmission of the test packet when it is determined that the transmission timeout time has elapsed. That is, the test packet is transmitted 16 times.

In the optical conversion bridge BR, the test packet is optically-electrically converted by the PHY-O.5 and transferred to the PHY-E.1 via the MAC switch 2. Then, the PHY-E.1 loops back the input test packet and transfers it to the PHY-O.5 via the MAC switch 2 again by the return path 9. This allows PHY
-O.5 carries out the electrical-optical conversion of the test pattern, and loops back to the optical conversion repeater RE via the optical fiber transmission line FB. On the other hand, in the optical conversion repeater RE, the looped back test packet is optoelectrically converted in PHY-O · 11 and input to the return path 21. Then, by the detection line 22 of the test packet insertion detection unit 15,
The looped back test packet is input to the control unit 14.

At this time, the loop-back test packet is discarded by the switching SW-24, and PHY-E-1
It is not transferred to 7. Further, when the control unit 14 detects the test packet, it is determined whether or not the received looped back test packet and the test packet transmitted by the control unit 14 match. At this time, the time T3 during which the determination of the looped back test packet is valid is
The 16th test packet after transmitting the 1st test packet takes into account the time required to loop back and return in the PHY-E.17 of the optical conversion device BR, that is, the 16th test packet. It is the time until the time when the test packet should arrive has been set by the timer setting unit 33. When the above-described loopback test ends normally, that is, the control unit 14 sets 16 during the time T3.
When one test packet is detected, the green LED of the LED section 18 is turned on. On the other hand, when abnormally terminated, that is, when 16 test packets are not detected during the time T3, the red LED of the LED unit 18 is turned on. (S
9)

Next, in the optical conversion repeater RE, when the determination of the loopback test by the test packet output from the optical conversion repeater RE ends, whether the result is normal or abnormal, that is, the green LED
Is turned on or the red LED is turned on, the loopback test by the measuring instrument M is possible, that is, the switching SW.16 is shifted to the normal mode (step S10), and the switching SW.24 is normal. The mode is shifted to (step S11). Then, from the measuring device M, for example, a test packet having a random packet length and a random pattern is transmitted to the optical conversion repeater RE, the optical conversion bridge BR loops the test packet through the optical conversion repeater, and the test packet is looped back. Is received by the measuring instrument M via the optical conversion repeater, and the test packet transmitted by the measuring instrument M and the test packet received by looping back are compared to test a random packet length and a random pattern. A loopback test using packets can be performed.

In the packet structure shown in FIG. 2 from the measuring instrument M, the source address SA and the destination address D
A is changed, a test packet is created, and the test packet is output to the optical conversion bridge BR via the optical conversion repeater RE. For example, the measuring device M outputs a plurality of test packets to the bridge BR by optical conversion while sequentially changing the source address with a normal packet length. This allows the MAC switch 2 to confirm the capacity of the address memory that stores the source address as the destination address. That is, since the measuring instrument M can output the destination address as a unicast address while sequentially changing it, the destination address stored in the address memory can be compared with the destination address of the newly input test packet. Since the contents of the address memory, that is, the stored destination address can be determined, a learning test for the destination address can be performed.

Further, since the measuring instrument M has a function of changing the source address, it is possible to generate a plurality of test packets having different source addresses. A test packet that uses only the source address and is stored can be output to the optical conversion bridge BR, and the above-described learning test can be performed on the entire address memory that stores the destination address. Test whether the memory device is operating normally. Further, the measuring device M makes the test packet into a random pattern with a variable length, outputs the transmission interval thereof to the optical conversion bridge BR at irregular intervals, and adjusts the transmission amount of the test packet to be looped back. Conduct more stringent loopback tests.

In addition, the measuring device M shortens or lengthens the packet length with respect to the specified width, and the MAC switch 2 tests the process of discarding the packet according to the packet length. In addition, a loopback test with a certain period is performed, and a test of an aging function in which the content of the address memory is reset within a predetermined period (for example, several minutes) is also performed (step S12). As described above, the number of transmissions and the transmission interval of the test packet transmitted from the measuring instrument M are changed, and the measuring instrument M compares the transmitted test packet with the received looped back test packet to perform the test. Even when the number of packets transmitted changes, it is possible to determine whether loopback is normal. Further, it becomes possible to remotely test the basic functions such as MAC address learning (transmission destination address learning function) and address aging of the MAC switch 2 of the optical conversion bridge BR.

Next, when the loopback test by the measuring instrument M is completed, the remote loop SW of the optical conversion repeater RE.
The test switch is turned off through the test switch 19 or the remote control device. (Step S1
3). Then, the control unit 14 determines the switching SW 24 and the switching SW based on the signal indicating that the test switch is in the OFF state.
13 is set to the loopback mode (steps S14, 1
5) Generate an end packet and send it to the optical conversion bridge BR. At this time, the generated end packet is
PHY-O.1 by switching SW.13 from control unit 14.
1 to the optical conversion bridge BR via the optical fiber transmission line FB (step S16). Then, the control unit 14 starts the time count using the timer setting unit 33 after transmitting the end packet 4 times, and determines whether or not the end ACK packet is received from the optical conversion bridge BR 3 times or more. To judge.

At this time, in the optical conversion bridge BR,
The end packet from the optical conversion repeater RE is input to the PHY-O.5 via the optical fiber transmission line FB, is optically-electrically converted, and is sent to the control unit 6 via the detection line 10 of the control packet insertion detection unit 3. Is entered. When the end packet is normally input three times, the control unit 6 switches the switch SW
4 is set to the loopback mode, an end ACK packet is generated and transmitted 4 times. As a result, the end ACK packet is transmitted from the switching SW-4 to the optical conversion repeater RE through the PHY-O-5 and the optical fiber transmission line FB (step S17).

Next, the control unit 6 sets the switching SW.4 to the normal mode, shifts (returns) the physical layer device of PHY-E.1 to the normal mode, and resets the MAC switch 2 to reset its address table. After clearing, shift (return) to the normal mode. Then, the control unit 6 controls the yellow L
The ED7 is turned off, the optical conversion bridge BR returns from the loopback test mode to the normal mode, and the loopback test ends (step S18). Next, the optical conversion repeater R
At E, the control unit 14 inputs the end ACK packet from the detection line 23 of the control packet insertion detection unit 12, and when it confirms that the three end ACK packets are not normally received, the timer is cleared and the red The LED is turned on to notify the outside that the remote loop test cannot be completed. On the other hand, when the control unit 14 confirms that the three end ACK packets are not normally received, the switching SW 13
Also, the switch SW 16 is set to the normal mode, the green LED and the yellow LED are turned off, and the loopback test is ended (steps S19 and S20). Here, the normality / abnormality of the end ACK packet in the control unit 14 is determined by the same processing as the normality / abnormality of the activation ACK packet described above.

Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like within a range not departing from the gist of the present invention. Even so, it is included in the present invention.

[0070]

As described above, according to the network system of the present invention, the loopback test from the first optical conversion device on the telecommunications carrier side to the second optical conversion device on the inside of the home is performed by the conventional network. Since the system is configured so that a loopback test can be performed by connecting a measuring instrument, the MA
Highly accurate loops can be performed because it is possible to effectively carry out tests that were not possible in the past, such as the learning function of the C switch and the processing of discarding packets based on the packet length, and the network system can be implemented with minimal changes. The back test can be realized at low cost.

According to the network system of the present invention,
In order to control the flow of each packet based on the test state by the switching means, the control packet is effectively exchanged with the second optical conversion device inside the home and the loopback test of the test packet is effectively performed, that is, the control packet. Since the data switching means blocks the test packet and the test packet from passing to the wide area LAN side, the test packet and the test packet are discarded.
A loopback test can be performed without causing an adverse effect on the N side. Further, according to the network system of the present invention, in the loopback test, based on the processing of the control packet from the first optical conversion device and the response packet from the second optical conversion device to this control packet, the system Since the start and stop of the loopback test can be effectively controlled and a measuring device can be connected to the first optical conversion device instead of the wide area LAN, various test packets can be transmitted to the second optical conversion device. It can be transmitted to the optical conversion device, and the test result of the looped back test packet can be effectively determined.

Further, according to the network system of the present invention, the control packet is transmitted to the user L by the MAC switch.
Since the passage to the AN side is blocked and discarded, the control packet does not flow out to the user LAN side, and the extra packet does not adversely affect the user LAN side. The control packet exchange and the test packet loopback test can be effectively performed. In addition, according to the network system of the present invention, the number of transmissions and the transmission interval of the test packet transmitted from the measuring instrument are changed, and the measuring instrument compares the transmitted test packet with the received looped back test packet. By doing so, it is possible to determine whether or not the loopback is normal even when the number of test packet transmissions changes. Further, according to the network system of the present invention, since the source address and the destination address of the test packet can be arbitrarily changed, the MAC address learning (the destination address learning function of the MAC switch of the second optical conversion device can be performed. ) And basic functions such as address aging can be tested remotely.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a configuration example of a network system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a configuration of an Ethernet (registered trademark) packet.

FIG. 3 is a block diagram showing a configuration example of a network system according to an embodiment of the present invention.

4 is a control section 1 of the optical conversion repeater RE shown in FIG.
4 is a block diagram showing a configuration example of No. 4 of FIG.

FIG. 5 is a control section 6 in the optical conversion bridge BR of FIG.
3 is a block diagram showing a configuration example of FIG.

FIG. 6 is a sequence diagram showing a method for testing a network system according to an embodiment of the present invention.

[Explanation of symbols]

1,17 PHY-E 2 MAC switch 3, 12 control packet insertion detector 4, 13, 16, 24 switch SW 5,11 PHY-O 6,14 Control unit 7 LED 8, 20 outward routes 9,21 Return line 10,22,23 Detection line 15 Test packet insertion detector 18 LED section 19 Remote loop SW 25 Data switching unit 30,56 Packet detector 31 Packet comparison unit 32,54 Packet generator 33,55 Timer setting section 34 PHY-O → PHY-E transfer control unit 35 Switch detector 36,52 LED control unit 51 PHY setting section 53 MAC switch setting section BR optical conversion bridge FB optical fiber transmission line LC carrier network LU user LAN M measuring device RE optical conversion repeater RK, RT router

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shoko Fujioka             2081-28 Tahara, Mashiki-machi, Kamimashiki-gun, Kumamoto             Kyushu Ando Electric Co., Ltd. (72) Inventor Makoto Ando             529-3 Kamata, Ota-ku, Tokyo Andoden             Ki Co., Ltd. F term (reference) 5K033 CC01 DA05 DB05 DB20 DB22                       EA02 EA05

Claims (9)

[Claims] 1. A user LAN and a wide area LAN of a telecommunications carrier
Is a network system for connecting the optical fiber transmission line and the optical fiber transmission line via an optical fiber transmission line, and is provided between the wide area LAN and the optical fiber transmission line, and is a first optical system for electrically / optically converting a data frame to be transmitted. A second conversion device, provided between the user LAN and the optical fiber transmission line, for electrically / optically converting a data frame to be transmitted, and transferring the data frame by medium access control;
And a control packet for controlling a loopback test between the first optical conversion device and the second optical conversion device, and the same as the data frame used for the loopback test. And a test packet having a different configuration, and transmits the test packet to the second optical conversion device via the optical fiber transmission path.
The measuring device for generating another test packet is connected to the wide area LAN.
In place of the above, the second optical conversion device has test control means for performing different loopback tests, and the second optical conversion device is based on a control packet from the first optical conversion device and is a physical layer with a user LAN. A network system having a loop control means for setting a termination point in a loopback test state and performing a loopback process of each of the test packets received via the optical fiber transmission line. 2. The first optical converter comprises an electrical physical layer termination unit connected to a wide area LAN, an optical physical layer termination unit connected to an optical fiber transmission line, and a control packet from the test control means. Through the optical physical layer terminating unit, to the second optical conversion device, the control packet insertion detection means for detecting a response packet from the second optical conversion device for the control packet, Test packet insertion detection means for transmitting a test packet from the test control means to the second optical conversion device and detecting a test packet looped back from the second optical conversion device, and control by the test control means 2. The network according to claim 1, further comprising: a data switching unit that controls permission / non-permission of packet transfer from the optical physical layer terminating unit to the electric physical layer terminating unit. Click system. 3. The packet control means for generating a test packet and a control packet including a start packet and an end packet for starting a loopback test, the test control means, and a response packet and an end packet for the start packet. A packet detecting means for detecting a response packet and a test packet to be looped back, a packet comparing means for comparing whether the test packet to be looped back and the transmitted test packet are matched, and a packet comparing means of the comparing means. 3. The network according to claim 2, further comprising: an informing means for informing a comparison result to the outside, and a data switching informing means for stopping transmission of the response packet and the test packet to be looped back to the wide area LAN side. system. 4. The second optical conversion device, in the physical layer, between the electrical-physical layer termination unit that performs packet transfer processing in the physical layer with the user LAN and the optical fiber transmission line. An optical physical layer terminating unit that performs packet transfer processing, and is provided between the electrical physical layer terminating unit and the optical physical layer terminating unit,
A MAC switch that transfers this packet according to the MAC address included in each packet, and is provided between the MAC switch and the optical physical layer termination unit and detects a control packet from the first optical conversion device. 2. The network system according to claim 1, further comprising control packet insertion detection means for supplying to the loop control means and transferring a response packet from the loop control means to the first optical conversion device. 5. The loop control means detects a control packet including a start packet and an end packet from the first optical conversion device, and a packet detection means, and the start and end packets in the packet detection means. When detecting, packet generating means for generating a response packet for each of them, when a start packet is detected by the packet detecting means, when the electrophysical layer termination unit is set to a loopback state, and when an end packet is received Loop setting canceling means for canceling the loopback state, and M when receiving the start packet and end packet.
The network system according to claim 4, further comprising reset means for resetting the AC switch. 6. A test method for performing a packet loopback test in the network system according to claim 1, wherein the first optical conversion device activates a loopback test. In the process of transmitting a packet to the second optical conversion device via the optical fiber transmission line, and in the second optical conversion device receiving the activation packet,
A process in which the electro-physical layer terminating unit with the user LAN is set to a loopback state, and a response packet corresponding to the activation packet and responding to the first optical conversion device from the second optical conversion device is an optical packet. In the process of being transmitted to the first optical conversion device via the fiber transmission line, and the first optical conversion device receiving the response packet,
A test packet with the same structure as the predetermined data frame
In the process of being transmitted to the second optical conversion device via the optical fiber transmission line and the second optical conversion device receiving the test packet,
A process in which the test packet is looped back at the end of the physical layer of the user LAN and looped back to the first optical conversion device via the optical fiber transmission line, and a loop received by the first optical conversion device. A step of comparing whether or not the backed-up test packet and the transmitted test packet match, a step of notifying the comparison result to the outside, A step of being connected to the electrical physical layer terminal of the optical conversion device, and a step of transmitting an arbitrary test packet transmitted from the measuring device to the second optical conversion device via an optical fiber transmission line. In the second optical conversion device, the received test packet is returned at the end of the electrical physical layer with the user LAN,
Looping back to the first optical conversion device via the optical fiber transmission line, and performing a loopback test on the second optical conversion device based on the test packet received by the measuring device. A method for testing a network system characterized by. 7. A second optical conversion device, wherein when the electro-physical layer termination unit with the user LAN is set to a loopback state based on the activation packet, the MAC switch is reset. 6. The network system test method according to item 6. 8. A process of transmitting an end packet to a second optical conversion device via an optical fiber transmission line when the loopback test is completed in the first optical conversion device, and a second optical conversion device. In the conversion device, based on the received end packet, a process of canceling the loopback setting of the electro-physical layer termination unit with the user LAN, and a response packet corresponding to the end packet are transmitted from the second optical conversion device. A process of transmitting to the first optical conversion device via an optical fiber transmission line and returning to a normal data communicable state, and in the first optical conversion device, based on the reception of the response packet, 8. The network system test method according to claim 6, further comprising a step of returning to a state in which data communication is possible. 9. The second optical conversion device resets the MAC switch when the end packet is received and the loopback setting of the electrical physical layer termination unit with the user LAN is released. 8. The network system test method according to item 8.