JP2003258833A - Inter-lan connection system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inter-LAN connection system capable of effectively testing an optical fiber transmission line. <P>SOLUTION: This inter-LAN connection system has a first inter-LAN connection device 1 for transferring a data frame between a wide LAN and the optical fiber transmission line, and a second inter-LAN connection device for transferring a data frame between a user LAN and the optical fiber transmission line. The first inter-LAN connection device is provided with a first control part 4, a first packet generation part 6 for transmitting a first control packet and a first test packet, and a first packet detection part 7 for detecting a second control packet and a second test packet. The second inter-LAN connection device is provided with a second control part 4a, a second packet detection part 7a for detecting the first control packet and the first test packet, and a second packet generation part 6a for transmitting the second control packet and the second test packet obtained by returning the first test packet. <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 LAN-to-LAN connecting device and a LAN-to-LAN connecting system, and more particularly to a LAN-to-LAN connecting device for transmitting an Ethernet (registered trademark) frame and a loopback test method therefor.

[0002]

2. Description of the Related Art In recent years, wide area LANs have been constructed in respective areas 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 developed nationwide. It is being put to practical use. An optical fiber is applied as the transmission line base, and so-called FTTO (fiber to the offic) is used.
e) or network service extended to user connection called FTTH (fiber to the home) has come to be provided. As is well known, as an inter-LAN connecting device for connecting LANs, an OSI (open syste
A bridge that connects at the data link layer level of the model, a router that connects at the network layer level, and a gateway that connects at a higher level than the transport layer are known. In particular, the bridge-type LAN-to-LAN connection uses TCP / IP (transmissi
LANs can be connected by an inexpensive device regardless of a higher-level protocol such as on control protocol / internet protocol).

By the way, when a user LAN is connected to a wide area LAN of a telecommunications carrier as described above via an optical fiber transmission line, the responsibility decomposing point of the telecommunications carrier is located at an end point inside the optical fiber transmission line. Therefore, maintenance and monitoring functions up to the terminal point are required. Therefore, Japanese Patent Application 200
Wide area of telecommunications carriers represented by 0-280893
First LAN installed between LAN and optical fiber cable
A second LAN in which the test packet transmitted from the inter-connection device and the transmitted test packet are installed between the optical fiber transmission line and the user LAN via the optical fiber transmission line.
The test result received by the first inter-LAN connecting device through the optical fiber transmission line after looping back at the inter-connecting device is compared, and the result is obtained by comparing the number of transmitted packets with the received packet. There was a method to notify the outside.

[0004]

However, in the above-mentioned method, when the test packet transmitted by the device A and the test packet received by the device A do not match, where does the test packet have a problem? There is a problem that it takes time to identify the cause, because it cannot be determined).

The present invention has been made in view of the above problems, and a wide area LA of a user LAN and a communication carrier.
LA that can connect N and LAN at low cost and can effectively test the optical fiber transmission line.
It is intended to provide an N-to-N connection system.

[0006]

According to a first aspect of the present invention, there is provided an inter-LAN connection system for connecting a user LAN and a wide area LAN of a telecommunications carrier via an optical fiber transmission line. A first inter-LAN connecting device for transferring a data frame to and from a transmission line; and a second inter-LAN connecting device for transferring a data frame between the user LAN and the optical fiber transmission line, The first LAN-to-LAN connecting device controls the loopback test with the second LAN-to-LAN connecting device, and a first control packet and a first test packet to the second LAN connecting device. A first packet generation unit for transmitting to a LAN-to-LAN connecting device, and a first packet detection for detecting a second control packet and a second test packet transmitted from the second LAN-to-LAN connecting device. And a second LAN
The inter-connection device includes a second control unit that controls a loopback test with the first inter-LAN connection device, a first control packet transmitted from the first inter-LAN connection device, and a first control packet. A second packet detection unit for detecting the second test packet, and a second test packet in which the second control packet and the first test packet are returned to the first inter-LAN connecting device. An inter-LAN connection system comprising:

According to a second aspect of the present invention, the second packet detecting section detects the number of received first test packets, and the second packet generating section detects the second detecting section. The number of the performed first test packets is included in the second control packet, and the first control unit is included in the second control packet detected by the first packet detection unit.
The number of the first test packets detected by the second detection unit and the number of the first test packets transmitted by the first packet generation unit are compared with each other. It is a LAN-to-LAN connection system.

According to a third aspect of the present invention, the second packet detector determines whether the received first test packet is normal or abnormal, and the second controller detects the second packet. The detection unit counts the number of first test packets normally received, and the second packet generation unit sets the number of first test packets counted by the second control unit to the second control packet. In addition, the first control unit includes
The number of first test packets counted by the second controller included in the second control packet detected by the first packet detector, and the number of first test packets transmitted by the first packet generator. The LAN-to-LAN connection system according to claim 1, wherein the number of test packets is compared with one.

The invention according to claim 4 is the user LAN.
And a wide area LAN of a telecommunications carrier are connected via an optical fiber transmission line.
And a first LAN connecting device for transferring a data frame between the optical fiber transmission line and a second L for transferring a data frame between the user LAN and the optical fiber transmission line.
A first packet transmitting step for transmitting a first control packet and a first test packet from the first LAN connecting device to the second LAN connecting device using the AN connecting device; Of the first control packet and the first test packet transmitted in the packet transmission step of 1. in the second inter-LAN connection device, and the first packet detection step detected in the first packet detection step. The second test packet and the second control packet obtained by folding back the first test packet are transmitted to the second L packet.
A second packet transmitting step for transmitting from the inter-AN connecting device to the first inter-LAN connecting device, and the second test packet and the second control packet transmitted in the second packet transmitting step are the first packet. And a second packet detection step of detecting with a LAN-to-LAN connecting device.

According to a fifth aspect of the present invention, in the first packet detecting step, the number of received first test packets is detected, and in the second packet transmitting step, the first packet detecting step is performed. The number of detected first test packets is included in the second control packet, and the second control packet is added.
In the packet detection step, the number of first test packets included in the second control packet detected in the first packet detection step and the first test packet transmitted in the first packet transmission step. The method for connecting between LANs according to claim 4, wherein the number of packets is compared.

According to a sixth aspect of the present invention, in the first packet detecting step, it is determined whether the detected first test packet is normal or abnormal, and the number of normal first test packets is counted. In the second packet transmitting step, the number of the first test packets counted in the first packet detecting step is included in the second control packet, and in the second packet detecting step, the second control packet is generated. And comparing the number of the first test packets counted in the first packet detection step included in the above with the number of the first test packets transmitted in the first packet transmission step. The inter-LAN connection method according to claim 4.

In order to solve the above-mentioned problems, a LAN-to-LAN connection system according to the present invention is a LAN-to-LAN connection system for connecting a user LAN and a wide area LAN of a communication carrier via an optical fiber transmission line. A first inter-LAN connection device installed on the operator side for converting a predetermined data frame transmitted between a wide area LAN and an optical fiber transmission line into a medium and transferring the data frame by medium access control; A second LAN connecting device installed in the user LAN for converting a data frame to be transmitted between a user LAN and an optical fiber transmission line into a medium and transferring the data frame by medium access control, the first LAN The inter-connection device is a control packet for controlling a loopback test with the second inter-LAN connection device, and is a second LAN
The second LAN-to-LAN connection device includes test control means for transmitting a control packet that is discarded during transfer processing in the inter-connection device, and further transmitting a test packet similar to a data frame to perform a loopback test. , A physical layer termination point with the user LAN is set to a loopback state based on a control packet from the first inter-LAN connecting device, and a test packet received via the optical fiber transmission line is connected to the first inter-LAN connection. In the present invention, the second LAN-to-LAN connection device detects the test packet before returning the test packet and determines whether the detected test packet is normal or abnormal. It includes a means to judge and notify the outside, and
And a means for transmitting the number of test packets normally received and detected from the LAN-to-LAN connecting device to the first media converting device via the optical fiber transmission line, and the first media converting device is a looped-back test. Packet to the first LA
A means for detecting the number of test packets transmitted by the N-to-N connecting device and the number of received test packets which is the number of receiving before the loopback transmitted from the second LAN-to-LAN connecting device is included, and the packet numbers are compared. It is characterized in that it is provided with means for externally notifying whether it is abnormal up to the turning point, abnormal after turning back, or normal.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an inter-LAN connection system according to the present invention will be described with reference to the accompanying drawings.

A LAN connecting device according to the present invention is a user L
It is used in an AN or wide area LAN for an inter-LAN connection system that transmits and receives data in packet units in Ethernet (registered trademark) frames.

The media converter (hereinafter referred to as MC), which is an inter-LAN connecting device of the inter-LAN connecting system, is 1000BASE.
-Gigabit MC (hereinafter referred to as GMC) that has an interface conversion function between SX and 1000BASE-LX. The GMC inside the office and the GMC inside the home are connected by two optical fibers for transmission and reception. Data communication is in progress.

For example, FIG. 1 illustrates an embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a LAN-to-LAN connection system (inside office GMC1 and inside home GMC2).

The block configuration in the station inner side GMC 1 will be described respectively.

The TEST switch unit 3 is a switch for starting / ending the loopback test of the station inner side GMC 1 and the house inner side GMC 2, and supplies a TEST start / end signal to the control unit 4. The TEST switch unit 3 is composed of a push button switch or the like.

The LED section 5 is a block for controlling the LED outside the apparatus so that the control section 4 notifies the result of the loopback test to the outside. Here, for example, "TESTO
It controls three LEDs, K, TXOK, and RXOK.

The control unit 4 controls the TE from the TEST switch unit 3.
A loopback test start packet generation notification is sent to the packet generation unit 6 by the ST start signal. The packet detection unit 7 detects the loopback test start response packet detection signal from the in-home GMC 2, and sends a loopback test packet generation notification to the packet generation unit 6 and to the switching SW unit 8 indicating that a loopback test is being performed. To supply. Further, it receives a signal from the packet detection unit 7 indicating whether or not a test packet has arrived, and determines whether or not this loopback test has succeeded. Then, it receives a TEST start / end signal from the TEST switch unit 3, outputs a signal for turning on the LED indicating that the loopback test is in progress to the LED unit 5, and outputs the result of the loopback test success / failure determination to the LED unit 5.
In addition, a test packet generation counter (counter A) that counts how many test packets are output to the control unit 4.
And a test packet reception counter (counter C) that counts how many normal test packets are returned.

The switching SW section 8 receives the loopback test signal from the control section 4, and receives the data packet on the main signal (signal carrying data) and the packet generation section 6.
This is a selector for exchanging test packets from The operation is to interrupt the transmission of the main signal to the in-home GMC2 during the loopback test and send a test packet to the in-home G.
Send to MC2.

The packet generation unit 6 is a block that receives various signals from the control unit 4 for starting a loopback test, during a test, and ending a test, generates a test packet, and supplies the test packet to the switching SW unit 8.

The packet detection unit 7 is a block that receives the test packet returned from the in-home GMC 2 and confirms the normality of the received test packet. As an operation, a loopback test start response packet is detected, and if the test packet transmitted from the in-home GMC 2 has an abnormality (bit error or the like), a signal indicating the abnormality is notified to the control unit 4. In addition, all test packets for maintenance that are not user data are discarded so that they do not go out to the user side PHY (hereinafter referred to as U-PHY) 9 so that the throughput of other devices does not drop out of the device itself. To do.

U-PHY 9 and L-PHY 10 are user side PHYs
9. Abbreviation for PHY 10 on the LINE side. The PHY is a physical layer device (PHY chip) that performs waveform shaping of signals such as packets (data packets) from the user side and the LINE side. Although signals are handled as parallel signals in GMC, since signals are serial signals in 1000BASE-X, parallel-serial conversion and Ethernet (registered trademark) encoding conversion of data are also performed.

Next, the block configuration of the in-home GMC 2 will be described.

The operations of the L-PHY 10a and the U-PHY 9a are exactly the same as those of the L-PHY 10 and the U-PHY 9 of the GMC 1 on the inside of the station, and the description thereof will be omitted.

The packet detection unit 7a is also similar to the packet detection unit 7 of the internal station GMC1, receives the test packet transmitted from the internal station GMC1, and determines whether the test packet is normal or not. 4a. When the loopback test start / test end packet is received, the detection signal is notified to the control unit 4a.

In addition, when a normal test packet is received, the counter in the control section 4a is incremented by +1.

The LED section 5a is a block for controlling the LED indicating the result of the loopback test. Here, the LED "TEST OK" is controlled.

The control unit 4a controls the operation of the entire loopback test. As the operation, first, when the loopback start command from the GMC1 on the inside of the station arrives, the U-PHY
The setting is made so that the data is returned at 9a, and then a signal is sent to the packet generation unit 6a so as to output a loopback test start response packet. After that, the packet detection unit 7a
Upon receiving the test packet detection signal from, the reception counter (counter B) counts the number of test packets and controls the switching SW unit 8a.

The packet generator 6a receives the packet generation signal from the controller 4a and generates a loopback test start response packet / loopback test end response packet,
It is sent to the switching SW section 8a. The packet generation unit 6a of the in-home GMC 2 operates only when this response packet is generated. In addition, the number of packets normally received so far is written and generated in the packet of the loopback test end response.

The switching SW section 8a is a selector. When receiving the signal from the control unit 4a and transmitting the loopback test response packet, the loopback test response packet generated by the packet generation unit 6a is transmitted to the U-PHY 9a, otherwise the main signal is transmitted. Send to U-PHY 9a.

Next, FIG. 2 shows an example of a test packet used for the loopback test.

The test packet conforms to the Gigabit Ethernet (registered trademark) frame format, and can be passed even if a MAC switch is built in the LAN-to-LAN connecting device. The content of the test packet in this case is
7 octets from the beginning of the frame to the preamble, SFD
1 octet, destination address 6 octets, source address 6 octets, Length field 2 octets, data field 485 octets, and FCS 4 octets last.

More specifically, a broadcast address of "FFFFFF (hex)" is put in the destination address. The reason for entering the broadcast address is to prevent the test packet from being deleted even if a MAC switch etc. is inserted in the middle. For the sender address, enter the vendor-specific MAC address. The reason for entering a vendor-specific MAC address is to distinguish test packets from other normal user data packets. Then 48 in the Length field.
A data size of 5 is entered, and in the data field, the content of the first 1 octet of data is first filled with the loopback test start packet / loopback test start response packet / loopback test end packet / loopback test end response packet / Differentiate test packets.
For example, in the case of a loopback test start packet, "AA (h)" is input in this part. For a loopback test start response packet, enter "A0 (h)" in this part.
In the case of a loopback test end packet, "F
Enter F (h) ". For loopback test end response packet, enter" F0 (h) "in this part. For test packet, enter" 00 (h) "in this part. .

In the next one octet, the value of the counter B is input only for the loopback test end response packet,
Enter "01 (h)" for other packets. Repeat "01 (h)" in the subsequent data fields until the total data field size reaches 485. After that, enter the value calculated by CRC as FCS.

A total of 503 octets of the destination field, the source address field, the Length field, the data field, and the FCS field will be referred to as a "test packet pattern".

Next, the procedure of the loopback test will be described with reference to FIG.

First, the TEST switch unit 3 of the station inner side GMC 1 is pressed, the control unit 4 confirms the start of the loopback test, and the packet generation unit 6 generates the loopback test start packet.
Instruct to. After that, the switching SW unit 8 is instructed to transmit the data from the packet generation unit 6 to the in-home GMC 2. The packet generator 6 receives a loopback test start request signal from the controller 4, generates a loopback start command packet, and transmits it to the in-home GMC 2.

On the other hand, in the in-home GMC 2, the packet detection section 7a receives the loopback test start packet,
The control unit 4a is notified of the result. First, the control unit 4a
After setting the U-PHY 9a to loop back the data for the loopback test, the switching SW unit 8a is switched so that the data from the packet generation unit 6a is sent to the U-PHY 9a, and the packet generation unit 6a performs the loopback test. Instruct to send start response. The packet generator 6a receives the signal and generates and transmits a loopback test start response. After that, the control unit 4a notifies the switching SW unit 8a to switch so that the data from the packet detection unit 7a is sent to the U-PHY 9a.

Upon receiving the loopback test start response packet, the packet detection unit 7 of the internal GMC 1 sends a signal indicating that it has been detected to the control unit 4. The control unit 4 receives the signal and notifies the packet generation unit 6 to generate a test packet. At this time, the value of the test packet generation counter (counter A) is incremented by 1 every time one test packet is generated inside the control unit 4.

Upon receiving the test packet from the in-station GMC1, the in-home GMC 2 confirms in the packet detection section 7a whether the test packet is normal, and if it is normal, it notifies the control section 4a.

Control unit 4a notified of normality
Receives the notification, and turns on the LED indicating that the downlink loopback test is successful. Also, the number of test packet reception counters (counter B) that counts normal packets is incremented by one.

Upon receiving the test packet returned by the U-PHY 9a of the in-home GMC2, the in-station GMC1 determines whether or not the packet is a normal test packet by the packet detection unit 7, and if it is normal, the control unit. Notify 4.

Upon receiving the notification, the control unit 4 turns on the LED indicating that the loopback test is successful, and at the same time, the value of the test packet reception counter (counter C) is incremented by +1.
To do.

After repeating the above process any number of times,
The control unit 4 of the internal GMC 1 notifies the packet generation unit 6 to generate the loopback test end packet, and the packet generation unit 6 transmits the loopback test end packet.

The in-home GMC 2 receives the loopback test end packet, instructs the packet generator 6a to generate a loopback test end response packet, and cancels the loopback setting of the U-PHY 9a. The packet generation unit 6a writes the value of the counter B in the data field portion of the loopback test end response packet, and transmits this to the intra-station GMC1 via the L-PHY 10a. This is the end of the operation of the in-home GMC2.

On the other hand, the internal GMC 1 receiving the loopback test end response is the internal G written in the internal GMC 1.
Check the value of Counter B of MC2.

In order to briefly explain the above operation, the value of the counter A (the number of test packets transmitted by the internal GMC1) is a, and the value of the counter B (the number of test packets received by the internal GMC2) is b, counter C value (inside station GMC
The number of test packets received by 1) is c. a, b, c
The value of is compared by the control unit 4 of the GMC 1 on the inside of the station. a, b,
c may be as follows. When a = b = c, this loopback test is completely successful because the number of transmissions and the number of receptions are the same. At this time, inside the station
GMC1 has the three LEDs ("TEST OK" and "TX OK") described above.
Turn on all "RX OK"). In the case of a> b = c Downward direction (direction from the GMC1 inside the station to the GMC2 inside the house)
In, it is thought that something is wrong. At this time, the station inside GMC1 turns on the "RX OK" LED. When a = b> c Upward direction (direction from GMC2 inside the home to GMC1 inside the office)
It seems that there is something wrong with. At this time, the station inside GMC1 turns on the LED of "TX OK". In the case of a>b> c It is considered that there is something wrong in both the up and down directions. At this time, the inside GMC1 turns off all three LEDs.

In addition, if there is no response even when the station inside GMC1 throws the loopback test start packet / loopback test end packet, if the maintenance person sees the lighting state of the LED of the home side GMC2 and turns it on. If it is turned off in the upstream direction, it can be easily understood that there is a failure in the downstream direction.

Next, the operation when the loopback test does not operate normally will be described with reference to FIG.

A case will be described in which there is an abnormality in the optical fiber for transmission, that is, the outward path, as viewed from the station inner side GMC1 side among the optical fibers connecting the station inner side GMC1 and the home side GMC2.

First, the TEST switch unit 3 of the station inner side GMC1 is pressed, and a loopback test start packet and a loopback test start response packet are exchanged between the station inner side GMC1 and the house side GMC2 (the procedure during this is the same as above). Omitted).
After that, a test packet is transmitted from the GMC1 on the inside of the station, but a bit error occurred because of an abnormality on this outward path,
The test packet becomes abnormal. At this time, the packet detection unit 7a discards this data here and notifies the control unit 4a of abnormal data detection. And at this time counter B
The value of is the same value (not incremented by 1).

Further, since the test packet is discarded here, the GMC 1 inside the office cannot receive the test packet.
For this reason, since a> b = c, the GM from the inside GCM1
It can be confirmed that an abnormality has occurred up to C2.
At this time, only the "RX OK" LED is lit.

Next, referring to FIG. 5, among the optical fibers for transmission and reception that connect the GMC 1 inside the office and the GMC 2 inside the premises, the GMC 1 inside the office
The case where there is an abnormality in the receiving optical fiber, that is, the return path of the test packet as viewed from the side will be described.

First, the TEST switch section 3 is pressed, and the inside of the station is
A loopback test start packet and a loopback test start response packet are exchanged between the GMC1 and the in-home GMC2 (the procedure during this is omitted because it is the same as above). Then inside the station
The test packet is transmitted from GMC1, the value of the counter A is incremented by 1, and the in-home GMC2 receives the test packet. If the normality of this test packet is confirmed and there is no error, this test packet is directly returned by the U-PHY 9a through the switching SW unit 8a and is transmitted to the internal GMC 1. At this time, the value of the counter B is incremented by 1.

On the other hand, since there is an error in the return path transmitted to the station internal GMC1, a test packet which is broken due to a bit error is received by the station internal GMC1. At this time, the packet detection unit 7 discards this data here and notifies the control unit 4 of the abnormal data detection of the test packet. At this time,
The value of counter C is not incremented by 1. Here, since the counter value is a = b> c, it can be confirmed that there is an abnormality on the return path. At this time, only the "TX OK" LED is lit. In addition, even if this packet itself cannot be received, it is possible to confirm whether there is an abnormality in the outbound path or the inbound path by checking whether the LED of the GMC2 inside the home is turned on or off.

With the above operation, the station inside GMC 1 can easily recognize the forward path abnormality / return path abnormality by the LEDs of the counter A / B / C and the home side GMC 2.

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 the scope not departing from the gist of the present invention. Even so, it is included in the present invention.

[0060]

As described above, according to the LAN-to-LAN connection system of the present invention, a wide area L is installed on the communication carrier side.
A first LAN connecting device for converting a predetermined data frame transmitted between an AN and an optical fiber transmission line into a medium and transferring the data frame by medium access control, and a user LAN and an optical device installed in a user's house. A second inter-LAN connecting device for converting a data frame to be transmitted to and from a fiber transmission path into a medium and transferring the data frame by medium access control, wherein the second inter-LAN connecting device is the second inter-LAN connecting device. The test packets received by the LAN-to-LAN connection device are notified to the outside, the received test packets are counted, and the total number of receptions during the test is the first LA.
The first LAN-to-LAN connecting device includes means for transmitting to the N-to-N connecting device,
The number of test packets received by the inter-connector and the second LA
A unit for detecting the total number of test packets received from the N-to-N connecting device before looping back,
It includes a means to notify the outside by comparing the numbers and whether it is abnormal until looping back, whether it is abnormal after being looped back, or normal, so when an abnormality occurs, it is better than before The cause of the abnormality can be found quickly.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a LAN-to-LAN connection system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a test packet used for a loopback test.

FIG. 3 is a diagram for explaining an operation when a loopback test does not operate normally.

FIG. 4 is a diagram illustrating a procedure of a loopback test.

FIG. 5 is a diagram for explaining a case where there is an abnormality in a receiving optical fiber, that is, a return path of a test packet when viewed from the station inner side GMC1 side among transmitting and receiving optical fibers connecting the station inner side GMC1 and the home side GMC2.

[Explanation of symbols]

1 Station inside GMC (first LAN connection device) 2 Home GMC (second LAN connection device) 3 TEST switch section 4 Control unit (first control unit) 4a Control unit (second control unit) 5, 5a LED section 6 Packet generation unit (first packet generation unit) 6a Packet generation unit (second packet generation unit) 7 Packet detector (first packet detector) 7a packet detector (second packet detector) 8, 8a switching SW section 9, 9a U-PHY 10, 10a L-PHY

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromi Takahashi             2081-28 Tahara, Mashiki-machi, Kamimashiki-gun, Kumamoto             Kyushu Ando Electric Co., Ltd. F term (reference) 5K030 GA12 HA08 HB29 HC01 HC14                       HD01 HD06 JA10 JL03 MA04                       MC02 MC07 MC08                 5K033 AA05 CC01 DA06 DB20 EA02                       EA04 EA06 EA07                 5K035 AA07 BB03 CC08 EE04 GG08

Claims (6)

[Claims] 1. A wide area LA of a user LAN and a communication carrier
In an inter-LAN connection system for connecting N via an optical fiber transmission line, a first inter-LAN connection device for transferring a data frame between the wide area LAN and the optical fiber transmission line, the user LAN and the optical fiber A second inter-LAN connecting device that transfers a data frame to and from a transmission path, wherein the first inter-LAN connecting device controls a loopback test with the second inter-LAN connecting device. A first packet generator that transmits a first control packet and a first test packet to the second LAN-to-LAN connecting device; and a first packet generator that transmits from the second LAN-to-LAN connecting device. A second packet for detecting a second control packet and a first packet detecting unit for detecting a second test packet, wherein the second inter-LAN connecting device is a router for connecting to the first inter-LAN connecting device. A second control unit for controlling a back test; a second packet detection unit for detecting a first control packet and a first test packet transmitted from the first LAN-to-LAN connecting device; A control packet and a second test packet in which the first test packet is folded back are used as the first L packet.
An inter-LAN connection system, comprising: a second packet generation unit for transmitting to an inter-AN connection device. 2. The second packet detection unit detects the number of received first test packets, and the second packet generation unit detects the first test packets detected by the second detection unit. A number is included in the second control packet, the first control unit includes the second control packet detected by the first packet detection unit, and the first detection unit detects the second detection packet detected by the second detection unit. The number of test packets of 1 and the first
2. The LAN according to claim 1, wherein the number of the first test packets transmitted by the packet generation unit is compared.
Inter-connection system. 3. The second packet detection unit determines whether the received first test packet is normal or abnormal, and the second control unit receives the second packet detection unit normally. Counting the number of first test packets, the second packet generating unit includes the number of first test packets counted by the second control unit in a second control packet, The control unit includes the number of first test packets counted by the second control unit and included in the second control packet detected by the first packet detection unit, and the first packet generation unit. L according to claim 1, characterized in that it compares the number of first test packets transmitted by
Inter-AN connection system. 4. A wide area LA of a user LAN and a communication carrier
In an inter-LAN connection method for connecting Ns via an optical fiber transmission line, a first inter-LAN connection device for transferring a data frame between the wide area LAN and the optical fiber transmission line, the user LAN and the optical fiber A second inter-LAN connecting device that transfers a data frame to and from a transmission line, and a first control packet and a first test packet from the first inter-LAN connecting device to the second inter-LAN connecting device And a first control packet and a first test packet transmitted in this first packet transmission step,
The first packet detection step detected by the inter-AN connection device, and the second test packet and the second control packet in which the first test packet detected in this first packet detection step is returned A second packet transmitting step for transmitting from the inter-LAN connecting device to the first inter-LAN connecting device, and the second test packet and the second control packet transmitted in the second packet transmitting step. L
A second packet detection step of detecting by an inter-AN connection device. 5. The first packet detection step detects the number of received first test packets, and the second packet transmission step detects the first test packets detected in the first packet detection step. Is included in the second control packet, and in the second packet detection step, the number of first test packets detected in the first packet detection step included in the second control packet and 5. The LA according to claim 4, wherein the LA is compared with the number of first test packets transmitted in the first packet transmitting step.
Connection method between N. 6. The first packet detecting step determines whether the detected first test packet is normal or abnormal, counts the number of normal first test packets, and outputs the second packet transmitting step. Then, the number of the first test packets counted in the first packet detecting step is included in the second control packet, and in the second packet detecting step, the number is included in the second control packet. The number of first test packets counted in the first packet detection step,
5. The method for connecting between LANs according to claim 4, wherein the number of first test packets transmitted in the packet transmitting step of is compared.