JP2003087291A - Inter-lan connection system and its alarm transfer system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively announce a fault in a user station or a repeating place to an enterprise when a user LAN is connected to the wide-area LAN of a communication enterprise by an optical fiber transmission line via the repeating site. SOLUTION: When a link disconnection or a power source interruption is detected in the transmission line, an optical conversion repeater 50 in the user station and first and second repeaters 80 and 90 in a repeater unit 70 generate an alarm packet which is shorter than the packet length of an 'Ethernet(R)' frame and transfer it to an optical conversion bridge 60 in the enterprise. In this case, the first and second repeaters 80 and 90 impart and transmit an identifying code expressing the packet's passage through the repeaters 80 and 90. The optical conversion bridge determines from which device each alarm packet is transferred, dicides its alarm kind and outputs the result to an external part. The alarm packet is shorter than a normal frame and abrogated by an MAC switch so that the alarm packet is not drained to the wide area LAN.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-LAN connection system and an alarm transfer system thereof, and more particularly to an inter-LAN connection system for transmitting Ethernet frames and an alarm transfer system thereof.

[0002]

2. Description of the Related Art In recent years, wide area LANs based on LAN (local area network) technology have been constructed in each area, and a wide area network in which these areas are further connected by a high-speed broadband backbone network has been deployed nationwide. Its practical application is being pursued. Optical fibers have been applied as the transmission line infrastructure to provide network services that extend to user connections, so-called FTTO (fiber to the office) or FTTH (fiber to the home).

Further, as is well known, as an inter-LAN connecting device for connecting LANs, OSI (open systems in
A bridge that connects at the data link layer level of the terconnection model, a router that connects at the network layer level, and a gateway that connects at an upper level above the transport layer are known. In particular, the bridge type LAN-to-LAN connection is performed via a common data link layer, and therefore TCP / IP (transmission control)
It is possible to connect LANs with an inexpensive device regardless of a higher-level protocol such as l protocol / internet protocol).

[0004]

By the way, the user LA
When N is connected to the wide area LAN of the telecommunications carrier by an optical fiber transmission line via a relay point, the telecommunications carrier's responsibility decomposition point is positioned at the terminal point inside the optical fiber transmission line, Maintenance and monitoring functions up to the terminal point including the relay point are required. However, in the conventional LAN-to-LAN connecting device as described above, the terminating device and the relay device at the user's house do not have sufficient maintenance and monitoring functions, and their development has been desired. In particular, when a bridge type terminating device is applied to each terminating point, there is a drawback that the device allows a broadcasting frame representing a broadcast to pass through. Therefore, for example, in the case of notifying the telecommunications carrier side of an abnormality inside the premises or an abnormality at the relay point, when the alarm packet is generated inside the premises and sent to the telecommunications carrier side, the alarm packet is transmitted to each LAN.
There is a possibility that the packet may pass through to the other side, and there is also a possibility that a packet leaked to another network may adversely affect communication. In addition, a relay device installed at a relay place also needs a function of notifying a failure. At that time, there is a problem that a function for distinguishing between a fault between the user LAN and the relay place or a fault occurring in the transmission path to the communication carrier is required.

The present invention has been made in view of the above problems, and a user LAN is used as a wide area LA of a communication carrier.
It is an object of the present invention to provide a LAN-to-LAN connection system and an alarm transfer method therefor capable of connecting LANs to N by an inexpensive device and effectively notifying a communication carrier of an abnormality inside a home or a relay place. And

[0006]

In order to solve the above-mentioned problems, a system for connecting LANs according to the present invention is provided by a user LA.
N10 and at least one wide area LAN20 of the communication carrier
An inter-LAN connection system for connecting by an optical fiber transmission line 40 via the above-mentioned relay place 30, wherein a data frame installed in a user's house and transmitted between the user LAN and the optical fiber transmission line is converted into an electrical signal. Then, the first conversion device 50 that transfers the data frame by medium access control, and the predetermined data frame that is installed between the wide area LAN and the optical fiber transmission path and is installed on the communication carrier side are converted into electric-optical conversion. Then, the second conversion device 60 that transfers the data frame by medium access control, and the first and second relays that are connected to each other by the electric transmission path 300 and installed at the respective relay points of the optical fiber transmission path. Which is a repeater device including an optical device for converting a data frame from the optical fiber transmission line 40 into an electric signal once and transmitting it again through the optical fiber transmission line. Relay device transfers and converts the No. 70
When the first conversion device 50 and the first and second repeaters 80 and 90 of the relay device monitor the input / output state of the data frame to / from the own device and detect the abnormality, A warning packet indicating each abnormality in the second packet
Alarm transfer control means 51 for transferring the alarm packet discarded by the converter 60 of the second converter 60 to the second converter 60 via the optical fiber transmission line including the relay station 30 or another repeater.
2, 812, 912, and further the first of the relay device 70.
And the second relays 80, 90 are connected to the first conversion device 50.
Alternatively, when the alarm packet transferred from the first repeater 80 to the second conversion device 60 passes through the device itself, the identification code assigning means 842 and 942 that assigns an identification code indicating the passage of the device to the alarm packet. The second optical conversion device 60 receives an alarm packet from the first optical conversion device 50 or the first repeater 80 or the second repeater 90 of the repeater device from the optical fiber transmission line, and outputs the alarm packet. It is determined whether the packet is from the first optical conversion device or the first or second repeater of the repeater, and the abnormality is judged, and the alarm represented by the alarm packet is output to the outside. An alarm output control means 640 is included.

In this case, the alarm packet is a packet formed to have a packet length shorter than the shortest packet length of the data frame to be transferred and processed in the second converter 60, and at least a predetermined pattern indicating the alarm type. And a predetermined identification code ID indicating whether the alarm packet is generated from the first conversion device 50 or the first or second repeater 80 or 90 of the relay device.
It is good to include and.

The alarm packet is sent to the second converter 6
0 is a packet having a length similar to the packet length of the data frame to be transferred, and a predetermined pattern indicating at least the type of alarm and an alarm generated from either the first conversion device 50 or the relay device 70. The packet may include an identification code indicating whether the packet is a packet and an error correction code of an alarm packet that is forcibly included an error.

Further, the first converter 50 and the first and second repeaters 80 and 90 of the relay device add a code having the same value as an identification code to the alarm packet and transmit the same, and the first packet of the relay device is transmitted. And, when the alarm packet transferred from each device passes through the device itself, the second repeater may add a predetermined value to the identification code and transfer it.

In these cases, the first converter 50 terminates the electrical physical layer terminating means 502 for terminating the electrical physical layer connected to the user LAN 10 and the optical physical layer connected to the optical fiber transmission line 40. Optical physical layer termination means 508,
The data frame is transmitted between the end means by the MAC.
MAC switch 504 that transfers according to the address, and M
The alarm transfer control means 512 includes at least an alarm packet insertion means 506 for inserting an alarm packet from the alarm transfer control means 512 into the transmission path to the optical fiber transmission line between the AC switch and the optical physical layer terminating means 508. , First monitoring means 530 for monitoring the link state with the user LAN in the electrical physical layer terminating means 502, and second monitoring means 532 for monitoring the link state with the optical fiber transmission line in the optical physical layer terminating means. A third monitoring means 534 for monitoring whether or not the power source of the device itself is normal, and a packet generating means for generating an alarm packet indicating the abnormality when any of the monitoring means detects an abnormality. 5
Advantageously, 36 is included.

Further, the first and second repeaters 80 and 90 of the relay device respectively have electro-physical layer terminating means 808 and 902 for terminating the electro-physical layer connected to the electric transmission path.
Optical physical layer terminating means 802, 908 for terminating the optical physical layer connected to the optical fiber transmission line, and transmission of alarm packets from the alarm transfer control means 812, 912 to the second converter 60 between these terminating means. The alarm packet inserting means 806.906 to be inserted in the route and the alarm packet detecting means 804,904 for detecting the alarm packet from the first conversion device 50 or the first relay 80 from the receiving route between the terminating means. Including, alarm transfer control means 81
Reference numerals 2 and 912 denote at least first monitoring means 83 for monitoring the link state with the electrical transmission line in the electrical physical layer termination means.
0, 930 and second monitoring means 832, 93 for monitoring the link status between the optical fiber transmission line in the optical physical layer termination means.
2 and a third that monitors whether the power supply of the device itself is normal
Of the monitoring means 834, 934 and the packet generating means 836, 936 for generating an alarm packet indicating the abnormality when the abnormality is detected in any of the monitoring means.
The identification code assigning means 842 and 942 add the predetermined value to the identification code of the alarm packet from the first conversion device or the first repeater detected by the alarm packet detecting means 804 and 904, and add the predetermined value. It is advantageous to include addition means for generating an identification code which indicates that the device has been passed.

Further, the second conversion device 60 is a wide area LA.
An electrical physical layer terminating unit 608 that terminates an electrical physical layer connected to N20, an optical physical layer terminating unit 602 that terminates an optical physical layer connected to the optical fiber transmission line 40, and a data frame between them. A MAC switch 606 that transfers according to the MAC address, and a first conversion device 50 or a first or second repeater 80 of a relay device between the MAC switch and the optical physical layer terminating means.
Alarm packet detecting means 604 for supplying the alarm packet from the alarm packet 90 to the alarm output control means 612 from the reception path, and the alarm output control means 612 has at least the alarm packet from the alarm packet detection means 604 as the first conversion device. An identification code determining unit 652 that determines whether the alarm packet is transmitted from the device 50 or the relay device 70.
It is advantageous to include alarm determination means 650 for determining which abnormality in the device is present, and alarm generation means 640 for issuing an alarm based on the result.

On the other hand, in the alarm transfer method according to the present invention, L connecting the user LAN and the wide area LAN of the communication carrier via an optical fiber transmission line including at least one or more relay points.
A first alarm transfer method in an inter-AN connection system, in which a data frame to be transmitted between a user LAN and an optical fiber transmission path inside a user's home is electro-optically converted and the data frame is transferred by medium access control. Of the above-mentioned converter is prepared, and a predetermined data frame to be transmitted between the wide area LAN and the optical fiber transmission line is electrically supplied to the communication carrier side.
A relay device that includes a second conversion device that optically converts the data frame and transfers the data frame by medium access control, and further includes first and second repeaters connected to respective relay points by an electric transmission path. A relay device that temporarily converts the data frame from the optical fiber transmission line into an electric signal, converts it again into an optical signal to be transmitted through the optical fiber transmission line, and transfers the optical signal is provided. The input state of the data frame and the input state of the data frame from the optical fiber transmission line are respectively monitored, and at the first and second repeaters of the relay device, the data frame from the optical fiber transmission line or the electric transmission line is monitored. An alarm packet that indicates each abnormality when the input status is monitored and an abnormality is detected during those monitoring. Then, an alarm packet which is discarded by the second conversion device is generated, and the alarm packet is transmitted to the second conversion device via an optical fiber transmission line including a relay point or another relay device, and at that time, the relay point is transmitted. Then, when an alarm packet from the first conversion device or the second relay device passes through the device itself, an identification code indicating the passage is added and transferred.

In this case, the second converter receives the alarm packet from the first converter or the first or second repeater of the repeater from the optical fiber transmission line, and the alarm packet receives the first packet. After determining whether it is from the converter or the first or second relay of the relay device and determining its abnormality, the alarm packet is discarded, and further, it is represented by the determination result of the alarm packet. It is advisable to output an alarm to the outside and notify it.

The alarm packet is a packet formed to have a packet length shorter than the shortest packet length of the data frame to be transferred and processed by the second converter, and the second converter converts the packet length of the alarm packet. Is judged, and it is good to discard as an abnormal packet from the length.

Further, the alarm packet is a packet having the same length as the packet length of the data frame to be transferred and processed in the second conversion device, and the error correction code thereof is forced to include an error. The second conversion device may determine an error in the alarm packet, determine an abnormal packet from the result, and discard it.

In these cases, the first conversion device and the first and second repeaters of the relay device further monitor whether or not the power source of the device itself is normal, and when the abnormality is detected. An alarm packet representing the alarm may be generated and transmitted to the second conversion device via the optical fiber transmission line.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a LAN-to-LAN connection system and its alarm transfer method according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows an embodiment of an inter-LAN connection system according to the present invention. The inter-LAN connection system according to the present embodiment, as shown in FIG. 4, joins a user LAN 10 and a wide area LAN 20 of a telecommunications carrier, which are separated by 50 km or more, by optical fiber transmission lines 40, 40 via a relay point 30. This is a user-network interface of a person access system, and in the present embodiment, the optical fiber transmission lines 40, 40 and an optical conversion repeater (first media converter (M
C)) 50 and an optical conversion bridge (second
Of the media converter (MC) 60 and a relay device 70 including first and second relays (third and fourth media converters (MC)) 80 and 90 installed in the relay station 30. This is a system for connecting between LANs.

In particular, in the present embodiment, in the optical conversion repeater 50 inside the house and the first and second repeaters 80 and 90 of the repeater 70, the link with the user LAN 10 or the optical fiber transmission lines 40 and 40 is broken. When an abnormality is detected, it is an alarm packet indicating the abnormality and is an LA packet.
An alarm packet shorter than the shortest packet length of the Ethernet frame transferred by N is generated, and the alarm packet is transferred to the optical conversion bridge 60 on the station side. The main characteristic point is that an alarm transfer method peculiar to the present application, in which an identification code indicating that the packet has passed through the device itself is added and transferred, is applied.

Explaining the details of each part, the user LAN 1
In the present embodiment, 0 is a 10Base-T or 100Base-T Ethernet LAN to which data terminals such as a plurality of personal computers are connected. It is preferable that the transmission band of 1 is selected and connected to the wide area LAN 20 by the inter-LAN connection system of the present embodiment. The user LAN 10 is connected to an optical conversion repeater 50 via a hub or a router 100 as shown in FIG. 1, for example. On the other hand, wide area LA
N20 is, for example, an Ethernet-based high-speed wideband LAN having a transmission band of several Gbps, and accommodates a plurality of user LANs 10 for each region and further 10
W connecting to each area via the 0 Gbps class backbone network
It forms an AN (wide area network). This wide area L
The AN 20 connects the optical conversion bridge 60 via the router 200.
It is connected to the.

The routers 100 and 200 are switches on the network layer level, and for example, IP (Internet prot.) In an Ethernet frame transmitted in this embodiment.
ocol) This is an inter-LAN connection device that distributes routes according to addresses. As shown in FIG. 8, an Ethernet frame includes a preamble PA that represents a synchronization signal, an 8-bit frame start delimiter SFD, and a destination MAC (media access control) address DA that represents an adjacent next destination.
And a source MAC address SA representing the source address
, A length type LT indicating a data length or a data type, transmission data DT of a variable length of 46 to 1500 octets including an IP header, and a destination MAC address DA
Pad PA that is added when the length from DT to data DT is less than 64 octets and is adjusted to the length of 64 octets
D and a frame check sequence FCS for error detection of a frame such as a CRC (cyclic redundancy check) code. The LAN-to-LAN connection system of this embodiment is a bridge-type LAN-to-LAN connection system that transfers each Ethernet frame based on an Ethernet header composed of a destination MAC address DA, a source MAC address SA, and a length type LT. .

More specifically, the optical conversion repeater 50 according to this embodiment is installed in the user's house and is installed in the user LAN 1.
Wide area LAN 20 transferred via the Ethernet frame from the router 100 of 0 and the optical fiber transmission line 40
Is a bridge-type connection device for mutually transferring Ethernet frames according to the MAC address thereof, and in the present embodiment, an Ethernet frame between an electric transmission line such as a twisted pair line from the router 100 and the optical fiber transmission line 40. It is an optical converter that performs electrical-optical conversion to control medium access. More specifically, the optical conversion repeater 50 of the present embodiment has an electrical physical layer terminating unit (PHY-E) 502 and a MAC switch 504 as shown in FIG. 2, for example.
, The alarm packet insertion unit 506, and the optical physical layer termination unit (P
HY-O) 508, a power supply unit 510, and a control unit 512.

The electrical physical layer termination unit 502 is the router 100.
It is a layer 1 termination circuit that terminates an Ethernet frame transmitted and received between
The connector includes a connector that can be commonly connected to 100Base-T, a PHY chip that performs processing such as frame waveform shaping, and a transformer that performs matching between the connector and the PHY chip. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to an input frame from the user LAN 10, and includes an internal register in which the content indicating the link state with the user LAN 10 is set based on the detected state. .
The PHY chip is connected to the control unit 512 by a control line, and is connected to the MAC switch 504 by a forward route and a backward route for transferring a frame.

The MAC switch 504 is a transfer processing unit for transferring a frame according to the MAC address of the Ethernet frame, and in the present embodiment, band switching capable of switching between 10Base-T and 100Base-T according to the band of the user LAN 10. It has a function. More advantageously, two switches are connected in series and the operating frequency is switched by an oscillator common to them, so that the user LAN 1
The transfer process may be performed according to the transmission speed of 0. The MAC switch 504 uses the alarm packet insertion unit 506 to send the optical physical layer termination unit 50 according to the forward route and the backward route.
8 is connected. The alarm packet insertion unit 506 is a part peculiar to this embodiment that inserts an alarm packet from the control unit 512 in the outward route at the time of alarm transfer. Changeover switch (SW-C) 520 provided on the outward route
And a detection line 522 commonly connected to the return route from the optical physical layer terminating unit 508 to the MAC switch 504. Although not directly related to this embodiment, the detection line 522 is a part that takes in a control packet or the like for remote operation from the optical conversion bridge 60, for example.

The optical physical layer terminating unit 508 is a layer 1 terminating circuit that terminates an Ethernet frame transmitted / received to / from the optical fiber transmission line 40.
It includes a line interface with the optical fiber transmission line 40 including an electric-optical conversion circuit, and a PHY chip that performs processing such as waveform shaping of a frame converted into an electric signal. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to a frame input through the optical fiber transmission line 40, and the optical fiber transmission line 40 is detected based on the detected state.
It includes an internal register in which the contents representing the link status with are set. This PHY chip uses a control line to control unit 5
12 and the contents of its internal register are controlled by the control unit 5
Supply to 12.

On the other hand, the power supply unit 510 has, for example, an alternating current 10
A power supply circuit that is connected to an input power supply of 0 V or −48 V DC and supplies a power supply voltage of, for example, a DC of 3 V to 5 V to each of the above parts. In the present embodiment, whether or not power supply from the input power supply is normal To the control unit 512 via a control line. By the way, in the present embodiment, an auxiliary power source such as a battery is included, which is switched when the input power source is cut off to secure an operating power source for alarm transfer. On the other hand, the control unit 512 is an alarm transfer control unit that mainly controls alarm transfer in this embodiment, and monitors the electrical physical layer termination unit 502, the optical physical layer termination unit 508, and the power supply unit 510, respectively. When an abnormality is detected, an alarm packet indicating the abnormality is sent out. For example, FIG. 5 shows functional blocks of the control unit 512 according to this embodiment. In this figure, the user link monitoring unit 530 receives the contents of the internal register of the electrical physical layer termination unit 502,
This is a first monitoring unit that monitors whether or not the electrical interface with the user LAN 10 is broken, and notifies the packet generation unit 536 of the result when the content of the internal register represents the broken link. The line link monitoring unit 532 receives the contents of the internal register of the optical physical layer termination unit 508 and monitors whether or not the line interface with the optical fiber transmission line 40 is broken.
When the content of the internal register indicates a link disconnection, the result is notified to the packet generation unit 536. The power supply monitoring unit 534 is a third monitoring unit that monitors whether or not the input power of the power supply unit 510 is cut off.
When the input power is cut off, the result is notified to the packet generation unit 536. Each monitoring unit 530,532,
When each abnormality is recovered, 534 notifies the packet generation unit 536 of the result.

The packet generation unit 536 is a unit for receiving the notifications from the respective monitoring units 530, 532, 534 and generating an alarm packet peculiar to the present embodiment. In the present embodiment, the abnormality at each position is detected. The alarm packet is repeatedly generated and transmitted until it is recovered. The alarm packet of this embodiment includes the UNR packet indicating the disconnection of the electrical interface on the user side and the optical fiber transmission line 40.
SEND indicating the disconnection of the line interface with
A packet, a SEND-UNR packet indicating that both of them are disconnected, and an R-representation of a power failure.
It includes an INH packet and an R-INH release packet indicating the restoration of power. Each alarm packet is formed to have a shorter packet length than the Ethernet frame shown in FIG. 8. For example, as shown in FIG. 9, a SEND packet has a data pattern of “0111”, a UNR packet has “1000”, and R-INH. The packet is "1001",
A 4-byte pattern PT is set by repeating the SEND-UNR packet of "0100". Further, each alarm packet other than the R-INH release packet represents the device identification unique to this embodiment.
A byte identification code ID is added to each to form a packet length of 5 bytes or 4 bytes in total. In the present embodiment, the identification code ID is set to a code common to the respective devices, for example, "0001", and when passing through a higher-level device, each is added with "0001" and transferred. Control unit 51 of optical conversion repeater 50
The alarm packets generated by No. 2 are inserted into the outgoing route and transmitted from the changeover switch 520 of the alarm packet inserting unit 506.

Further, in FIG. 5, a timer 538 is a timing circuit for measuring the timing of sending an alarm packet in the packet generator 536. In the present embodiment, a timing representing a predetermined gap between packets, for example, an interval of 960 ns. The signal is supplied to the packet generator 536. The packet generation unit 536 generates an alarm packet in response to the timing signal. In this case, for example, when a notification is received from the user link monitoring unit 530 while transmitting a SEND packet, the SEND packet sends SEND-U.
Switch to NR packet and transmit. Also, if a notification is received from the line link monitoring unit 532 while transmitting the UNR packet, the SEND-UNR is transmitted from the UNR packet.
Switch to packet and send. On the other hand, the LED control unit 5
In response to the transmission of the alarm packet, 40 is an LED drive that turns on or off a plurality of LEDs (not shown) according to the respective abnormalities when the link on the user side, the link on the line side, or the power source is cut off. Circuit.

Returning to FIG. 1, the repeater 70 according to the present embodiment uses the optical fiber transmission lines 40, 40 to send the user L.
A connection device that relays Ethernet frames that are mutually transferred between the AN 10 and the wide area LAN 20,
The present embodiment includes a first repeater 80 and a second repeater 90 which are connected to each other by an electric transmission path 300. The first repeater 80 of the present embodiment performs opto-electric conversion on a frame transmitted between the optical fiber transmission line 40 from the optical conversion repeater 50 and the electric transmission line 300 from the second repeater 90. This is a conversion device for transfer, and in the present embodiment, as shown in the figure, an optical physical layer termination unit (PHY-O) 802.
An alarm packet detection unit 804, an alarm packet insertion unit 806, an electrical physical layer termination unit (PHY-E) 808,
A power supply unit 810 and a control unit 812 are included.

The optical physical layer terminating unit 802 is a layer 1 terminating circuit for terminating an Ethernet frame transmitted / received to / from the optical fiber transmission line 40, and more precisely, an optical fiber transmission line including an electro-optical conversion circuit. 40, and a PHY chip that performs processing such as waveform shaping of a frame converted into an electric signal. In particular, P
The HY chip has a signal detection unit that detects a current waveform corresponding to a frame input via the optical fiber transmission line 40, and the content indicating the link state with the optical fiber transmission line 40 is set based on the detected state. Including internal registers. This PHY chip has a control unit 812 by a control line.
Further, it is connected to the electrical physical layer terminating unit 808 by a forward route and a backward route via the alarm packet detection unit 804 and the alarm packet insertion unit 806.

The alarm packet detection unit 804 detects the alarm packet transferred from the optical conversion repeater 50 via the optical fiber transmission line 40 from the outward route from the optical physical layer termination unit 802 to the electrical physical layer termination unit 808. This is a part peculiar to the present embodiment, which is supplied to the control unit 812 and further inserts the alarm packet to which the identification code ID is added to the outward route again. In the present embodiment, the optical physical layer termination unit 802 to the electrical physical layer termination unit Includes a detection line 820 commonly connected to the outbound route to 808. The outgoing route is connected to the electrical physical layer termination unit 808 via the alarm packet insertion unit 806. The alarm packet inserting unit 806 is a part peculiar to this embodiment that inserts an alarm packet generated by the control unit 812 in the outward route at the time of alarm transfer from the own device, and in this embodiment, from the optical physical layer terminating unit 802. A changeover switch (SW-C) 822 provided on the outward route to the electrical physical layer termination unit 808 is included.

The electrical physical layer terminating unit 808 is used for the electrical transmission line 3
00 is a layer 1 terminating circuit that terminates an Ethernet frame transmitted and received with respect to 00, and in the present embodiment,
An electrical interface connected to the electrical transmission line 300,
A PHY chip that performs processing such as frame waveform shaping,
A transformer for matching between the electrical interface and the PHY chip. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to a frame from the electric transmission path 300, and has an internal register in which the content indicating the link state with the electric interface is set based on the detection result. Including. This PHY chip is connected to the control unit 812 by a control line, and the contents of its internal register are supplied to the control unit 812. On the other hand, the power supply unit 810 is, for example, a power supply circuit that is connected to an input power supply of 100 V AC or −48 V DC and supplies a power supply voltage of, for example, 3 V to 5 V DC to each of the above units. An input detection circuit for supplying whether or not the power supply is normal to the control unit 812 via a control line is included. By the way, in the present embodiment, an auxiliary power source such as a battery is included, which is switched when the input power source is cut off to secure an operating power source for alarm output.

On the other hand, the control unit 812 is an alarm transfer control unit that mainly controls alarm transfer in the present embodiment, and is an electrical physical layer terminating unit 802, an optical physical layer terminating unit 808, and a power supply unit 8.
When 10 and 10 are respectively monitored and an abnormality is detected, an alarm packet indicating the abnormality is transmitted. For example, in Figure 7,
Functional blocks of the control unit 812 according to the present embodiment are shown. In this figure, the line link monitoring unit 832
Is a first monitoring unit that receives the contents of the internal register of the optical physical layer terminating unit 802 and monitors whether the optical interface with the optical fiber transmission line is disconnected or not. When the link is disconnected, the result is notified to the packet generation unit 836. The user link monitoring unit 830 receives the contents of the internal register of the electrical physical layer termination unit 808 and monitors whether or not the line interface with the electrical transmission line 300 is disconnected.
When the content of the internal register indicates a link disconnection, the result is notified to the packet generation unit 836. The power supply monitoring unit 834 is a third monitoring unit that monitors whether or not the input power of the power supply unit 810 is cut off.
When the input power is cut off, the result is notified to the packet generation unit 836. The respective monitoring units 830, 832
When each abnormality is recovered, the 834 notifies the packet generation unit 836 of the result.

The packet generation section 836 is a section for receiving the notifications from the respective monitoring sections 830, 832, 834 and generating an alarm packet peculiar to the present embodiment. In the present embodiment, the abnormality at each point is detected. The alarm packet is repeatedly generated and transmitted until it is recovered. As with the optical conversion repeater 50, the alarm packet according to the present embodiment includes a UNR packet indicating a disconnection of a user-side electrical interface, a SEND packet indicating a disconnection of a line interface with the optical fiber transmission line 40, and a SEND packet indicating the disconnection. Both include a SEND-UNR packet indicating that the link has been disconnected, an R-INH packet indicating that the power supply has been disconnected, and an R-INH release packet that indicates that the power supply has been restored. Each alarm packet, like the optical conversion repeater 50,
As shown in FIG. 8, it includes a predetermined pattern PT and an identification code ID. The generated alarm packets are inserted into the outgoing route from the changeover switch 822 of the alarm packet insertion unit 806 and transmitted.

Returning to FIG. 7, the timer 838 is a timing circuit for measuring the timing of sending an alarm packet in the packet generator 836. In the present embodiment, a timing representing a predetermined gap between packets, for example, an interval of 960 ns. The signal is supplied to the packet generation unit 836. The packet generation unit 836 generates an alarm packet in response to the timing signal. In this case, for example, when a notification is received from the user link monitoring unit 830 while transmitting the SEND packet, the SEND packet is switched to the SEND-UNR packet and transmitted. Further, when a notification is received from the line link monitoring unit 832 while transmitting the UNR packet, the UNR packet is switched to the SEND-UNR packet and transmitted. Meanwhile, the LED control unit 840
Is an LED drive circuit that turns on or off a plurality of LEDs (not shown) in response to the transmission of an alarm packet when a user side link is disconnected, a line side link is disconnected, or a power supply is disconnected according to each abnormality. Is. On the other hand,
The device identification code generation unit 842 is a part peculiar to the present embodiment, and is a circuit that adds an identification code indicating the passage to the alarm packet from the optical conversion repeater 50 detected by the alarm packet detection unit 804. For example, the present embodiment includes an adder circuit that adds "0001" to the identification code of the detected alarm packet. The alarm packet to which the identification code is added is inserted again on the outward route to the changeover switch 822 and transferred to the second relay 90.

Returning to FIG. 1 again, the second embodiment
The relay 90 of the electric transmission line 3 from the first relay 80
00 and optical conversion bridge 60 from optical fiber transmission line 40
Is a connection device for optical-electrically converting and transmitting a frame to be transmitted between the first and second relays 80, and as shown in FIG.
An alarm packet detection unit 904, an alarm packet insertion unit 906, an optical physical layer termination unit 908, a power supply unit 910,
And a control unit 912. The electrical physical layer terminating unit 902 is a layer 1 terminating circuit that terminates an Ethernet frame transmitted to and received from the electrical transmission path 300, and, like the electrical physical layer terminating unit 808 of the first repeater 80, electrical transmission is performed. It includes an electrical interface connected to the path 300, a PHY chip for performing processing such as frame waveform shaping, and a transformer for matching between the connector and the PHY chip.
In particular, the PHY chip has a signal detection unit that detects a current waveform according to an input frame from the electric transmission path 300,
It includes an internal register in which contents representing the link state with electric transmission line 300 are set based on the detected state. This PHY chip is connected to the control unit 912 by a control line, and is also connected to the optical physical layer terminating unit 908 by a forward route and a backward route via the alarm packet detection unit 904 and the alarm packet insertion unit 906.

The alarm packet detector 904 detects the alarm packet transferred from the optical conversion repeater 50 via the first repeater 80 from the outgoing route from the electrical physical layer terminating unit 902 to the optical physical layer terminating unit 908. To the control unit 912,
Further, the alarm packet to which the identification code is added is inserted into the outward route again, and is a part peculiar to the present embodiment. . The outgoing line is connected to the optical physical layer terminating unit 908 via the alarm packet inserting unit 906. The alarm packet insertion unit 906 is a part peculiar to this embodiment that inserts an alarm packet generated by the control unit 912 in the outward route at the time of alarm transfer from the own device, and in this embodiment, from the electrical physical layer termination unit 902. Changeover switch (SW- provided on the outward route to the optical physical layer termination unit 908)
C) 922 included.

The optical physical layer terminating unit 908 is a layer 1 terminating circuit for terminating an Ethernet frame transmitted / received to / from the optical fiber transmission line 40 to the optical conversion bridge 60, and in the present embodiment, the first relay. Similar to the optical physical layer terminating unit 802 of the device 80, the line interface connected to the optical fiber transmission line 40, the PHY chip for performing processing such as frame waveform shaping, and the matching between the line interface and the PHY chip are performed. Including a trance. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to a frame from the optical fiber transmission line 40, and an internal register in which the content indicating the link state with the electrical interface is set based on the detection result. including. This PHY chip is connected to the control unit 912 by a control line, and the contents of its internal register are supplied to the control unit 912. On the other hand, the power supply unit 910 is a power supply circuit which, like the first repeater 80, is connected to an input power supply of 100 V AC or −48 V DC and supplies a power supply voltage of, for example, 3 V to 5 V DC to the above units, The present embodiment includes an input detection circuit that supplies to the control unit 912 via the control line whether or not the power supply from the input power supply is normal. By the way,
In the present embodiment, an auxiliary power source such as a battery is included, and when the input power source is cut off, it is switched to secure the operating power source for alarm output.

On the other hand, the controller 912 controls the first repeater 80.
The alarm transfer control unit controls the alarm transfer similarly to the control unit 812 of the above, and when an abnormality is detected by monitoring the electrical physical layer terminating unit 902, the optical physical layer terminating unit 908, and the power supply unit 910, respectively. An alarm packet indicating the abnormality is sent out. The functional configuration of the control unit 912 according to the present embodiment is shown in FIG.
Is formed in substantially the same manner as the control unit 812 of the first repeater 80 shown in FIG. 2, and the user link monitoring unit 930 that monitors the link state at the electrical physical layer termination unit 902 and the link at the optical physical layer termination unit 908. A line link monitoring unit 932 that monitors the status, a power supply monitoring unit 934 that monitors the power supply status, a packet generation unit 936 that generates an alarm packet when an abnormality is detected by these monitoring units 930, 932, and 934, and packet generation timing. A timer 938 for counting the time, an LED control unit 940 for controlling the LED when an abnormality is detected,
Identification code generation unit 9 for giving an identification code to an alarm packet
42 and 42. In particular, the identification code generation unit 942 adds the identification code to the alarm packet supplied from the optical conversion repeater 50 via the first relay 80 or the alarm packet supplied from the first relay 80. 0001 "
And an adder circuit for adding.

On the other hand, the optical conversion bridge 6 according to the present embodiment
Reference numeral 0 denotes a MAC bridge which is installed on the communication carrier side and mutually transfers the Ethernet frame from the router 200 of the wide area LAN 20 and the Ethernet frame from the user LAN 10 transferred via the optical fiber transmission line 40 according to the MAC address thereof. Yes, in this embodiment,
Electricity of an Ethernet frame between an electric transmission line such as a twisted pair from the router 200 and the optical fiber transmission line 40-
It is an optical converter that performs optical conversion to control medium access. More specifically, the optical conversion bridge 60 of this embodiment.
As shown in FIG. 3, an optical physical layer termination unit (PHY-O).
602, an alarm packet detection unit 604, a MAC switch 606, an electrical physical layer termination unit (PHY-E) 608,
The power supply unit 610 and the control unit 612 are included. The optical physical layer terminating unit 602 is a layer 1 terminating circuit that terminates an Ethernet frame transmitted to and received from the optical fiber transmission line 40, and to be exact, the optical fiber transmission line 40 including an electrical-optical conversion circuit. PH that performs processing such as line interface and waveform shaping of frames converted to electrical signals
Including Y chip. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to a frame input via the optical fiber transmission line 40, and indicates the link state with the optical fiber transmission line 40 based on the detected state. Includes an internal register in which is set. This PHY chip is connected to the control unit 612 by a control line, and is also connected to the MA by the forward route and the backward route via the alarm packet detection unit 604.
It is connected to the C switch 606.

The alarm packet detector 604 detects an alarm packet from the optical conversion repeater 50 or the first or second repeater 80, 90 from the outgoing route between the optical physical layer terminating unit 602 and the MAC switch 606. And a detection line 620 that is commonly connected to the forward route from the optical physical layer terminating unit 602 to the MAC switch 606 and an optical signal from the MAC switch 606. A changeover switch (SW-C) 622 provided on the return route to the physical layer termination unit 602 is included. Incidentally, the changeover switch 622 is used when the control packet generated in the control unit 612 is inserted in the return route when the optical conversion repeater 50 is remotely controlled. The MAC switch 606 is a transfer processing unit that transfers a frame according to the MAC address of the Ethernet frame, and in the present embodiment, for example, two switches are connected in series to limit the bandwidth of data flowing out to the wide area LAN 20 side. A band control function may be included. That is, when the operating frequency of the two switches is determined by the common oscillator, the writing and reading of the data in the respective buffers are controlled, and when the data band flowing from the user LAN 10 side exceeds the contract band, Execute the process to discard the frame. The MAC switch 606 is connected to the electrical physical layer terminating unit 608 by the forward route and the backward route.

The electrical physical layer terminating unit 608 is the router 200.
It is a layer 1 terminating circuit that terminates an Ethernet frame transmitted and received to and from
/ 100Base-T, a connector common to the / 100Base-T, a PHY chip for performing processing such as frame waveform shaping, and a transformer for matching between the connector and the PHY chip. In particular, the PHY chip has a signal detection unit that detects a current waveform corresponding to a frame from the wide area LAN 20, and includes an internal register in which the content indicating the link state with the electrical interface is set based on the detection result. This PHY
The chip is connected to the control unit 612 by a control line, and the contents of its internal register are supplied to the control unit 612. On the other hand, the power supply unit 610 is, for example, a power supply circuit which is connected to an input power supply of AC 100V or DC -48V and supplies a power supply voltage of DC 3V to 5V to the above respective units,
The present embodiment includes an input detection circuit that supplies to the control unit 612 via the control line whether or not the power supply from the input power supply is normal. By the way, in the present embodiment, an auxiliary power source such as a battery is included, which is switched when the input power source is cut off to secure an operating power source for alarm output.

On the other hand, the control unit 612 is, in this embodiment, mainly based on the alarm packet from the optical conversion repeater 50 or the first or second repeater 80, 90, and is represented by the alarm packet. Is an alarm output control unit that outputs the abnormality of
Includes alarm output when an abnormality is detected in the device itself.
For example, FIG. 6 shows functional blocks of the control unit 612 according to this embodiment. In this figure, the line link monitoring unit 630 receives the contents of the internal register of the optical physical layer terminating unit 602 and monitors whether or not the line interface with the optical fiber transmission line 40 is disconnected. This is a monitoring unit and notifies the alarm output unit 640 of the result when the content of the internal register indicates the disconnection of the link. The station side link monitoring unit 632 receives the contents of the internal register of the electrical physical layer terminating unit 608, and receives the wide area LAN 20.
It is a second monitoring unit that monitors whether or not the electrical interface with the link is broken, and when the content of the internal register indicates the link is broken, the result is output to the alarm output unit 6
Notify 40. The power supply monitoring unit 634 is a third monitoring unit that monitors whether or not the input power supply of the power supply unit 610 is cut off, and notifies the alarm output unit 640 of the result when the input power supply is cut off. .

On the other hand, the packet judgment unit 636 is a judgment unit for judging an alarm represented by an alarm packet supplied via the alarm packet detection unit 604. In this embodiment, the packet PT of the alarm packet is detected and the alarm packet pattern PT is detected. Abnormality determination unit 6 for determining the type of alarm represented by the pattern
50, and an identification code determining unit 652 that detects the identification code ID and determines from which device the alarm packet is from. Further, in the alarm packet detection method according to this embodiment, when the alarm packets are continuously detected a predetermined number of times, a detection signal indicating the detection of each alarm packet is supplied to the alarm output unit 640. For example, SEN
When the D packet is detected, when the SEND packet or the SEND-UNR packet is sampled every second, for example, two consecutive times, a detection signal representing the result is supplied to the alarm output unit 640. After that, when the SEND packet or the SEND-UNR packet is undetected four times in succession by sampling every one second, for example, a recovery signal for stopping the alarm output is supplied to the alarm output unit 640. When a UNR packet is detected, for example, when the UNR packet is repeated twice or S
When the END-UNR packet is sampled every second, for example, when the detection signal representing the result is consecutively detected twice, for example, is supplied to the alarm output unit 640, and then the UNR packet is not detected for four consecutive times, or If the SEND-UNR packet is undetected four times in a row by sampling every one second, the recovery signal is similarly supplied to the alarm output unit 640. When the R-INH packet is detected, when the same packet continues twice, for example, the detection signal of the result is supplied to the alarm output unit 640. To recover from the power cut, for example, after detecting the R-INH release packet twice in a row and then stopping the detection of another alarm packet for 2 seconds to confirm the recovery of the line link, a recovery signal is output as an alarm. Supply to the section 640. The timer 638 is a timing circuit that measures the detection timing of the packet determination unit 636, and supplies a timing signal indicating the detection timing of each alarm packet.

The alarm output unit 640 receives the notification from the line link monitoring unit 630, the station side link monitoring unit 632, the power supply monitoring unit 634 or the packet determination unit 636, and generates an alarm indicating each abnormality. Thus, in the present embodiment, for example, an alarm device (not shown) is driven by the ground output in accordance with each abnormality. The alarm device is a line link disconnection alarm in the optical conversion bridge 60, a station side link disconnection alarm, a power supply disconnection alarm, a line link disconnection alarm in the optical conversion repeater 50 or the first or second repeaters 80 and 90, the user side. It is an informing device for externally issuing an alarm such as a link disconnection alarm and a power supply disconnection alarm. On the other hand, L
The ED control unit 642 is an LED drive circuit that responds to each alarm and turns on or off a plurality of LEDs (not shown) representing the abnormal parts according to each abnormality.

Next, the alarm transfer method according to the present embodiment will be described with reference to FIG. 10 together with the operation of the LAN-to-LAN connection system. In the operating state, an Ethernet frame addressed to another LAN from the user LAN 10 is converted into an optical conversion repeater. From the optical fiber transmission line 40 to the optical fiber transmission line 40 to the optical conversion bridge 60 after being relayed from the optical fiber transmission line 40 by the first and second repeaters 80 and 90 of the repeater 70. It is transferred and supplied to the optical conversion bridge 60, and further, the optical conversion bridge 6
0 to the wide area LAN 20. In this case, for example, if a transmission path failure occurs between the user LAN 10 and the optical conversion repeater 50, the input of the data frame to the electrophysical layer termination unit 502 of the optical conversion repeater 50 is stopped.
As a result, the internal register is set to the link disconnection in the electrical physical layer termination unit 502, and when this is detected by the control unit 512, UNR packets indicating the user side link disconnection are sequentially generated at a predetermined interval, and the alarm packet insertion unit 506 is generated. Of the changeover switch 520. that time,
An identification code of, for example, "0001" indicating the device identification is added to the pattern PT indicating the UNR packet. The UNR packet supplied to the changeover switch 520 is MAC
The first repeater 80 of the repeater 70 is sequentially inserted in the outward route from the switch 504 to the optical physical layer terminating unit 508, and is further converted into an electric-optical signal in the optical physical layer terminating unit 508 and is transmitted through the optical fiber transmission line 40. Transferred to.

Next, in the first repeater 80 which receives the UNR packet from the optical conversion repeater 50 via the optical fiber transmission line 40, the alarm packet detection unit 804 causes the optical physical layer termination unit 802 to the electrical physical layer termination unit. When the UNR packet is detected from the outward route to 808, this is detected by the control unit 81.
Supply to 2. In the control unit 812 that has received the UNR packet, the identification code generation unit 832 causes the identification code “00”.
"01" is detected, "0001", that is, "1" is added to this, and the value is set to "0010". The UNR packet to which the identification code is added is the alarm packet insertion unit 806.
Insert it in the outgoing route to the electrical physical layer termination unit 808,
Further, it is transferred to the second repeater 90 via the electric transmission path 300. Next, the second repeater 9 that receives the UNR packet from the optical conversion repeater 50 via the first repeater 80
0, like the first repeater 80, when the alarm packet detecting unit 904 detects the UNR packet from the outward route from the electrical physical layer terminating unit 902 to the optical physical layer terminating unit 908, the control unit 912 Supply to. Similarly, in the control unit 912, "0001" is further added to the identification code which has become the value "0010" by the identification code generation unit 942, and the value is set to "0011". The UNR packet to which the identification code is added is inserted by the alarm packet inserting unit 906 in the outward route to the optical physical layer terminating unit 908, is further converted into an optical signal by the optical physical layer terminating unit 908, and is transmitted through the optical fiber transmission line. 40.

Next, the UNR packet transferred from the repeater 70 to the optical conversion bridge 60 via the optical fiber transmission line 40 is an optical physical layer terminating unit 602 of the optical conversion bridge 60.
Is converted into a light-electricity and transferred to the outward route to the MAC switch 606. Thereby, the UNR packet is sequentially supplied to the control unit 612 via the detection line 620 of the alarm packet detection unit 604. At this time, the UNR packet is also input to the MAC switch 606 from the outward route,
Since the packet length of the UNR packet is shorter than the Ethernet frame normally transferred, the MAC switch 606 discards the UNR packet as an abnormal packet. on the other hand,
When the control unit 612 detects UNR packets, for example, twice consecutively, the packet determination unit 636 detects
The value of the identification code is determined to identify the alarm packet from the optical conversion repeater 50 that has passed through the first and second repeaters 80 and 90 of the repeater 70. Next, it is determined from the value of the pattern PT that the alarm indicates a link disconnection on the user side, an alarm output of the result is generated, and an alarm device, for example, notifies the outside.

Further, in the above case, if the line from the optical fiber transmission line 40 to the optical conversion repeater 50 is disconnected after or simultaneously with the disconnection on the user side, the inside of the optical physical layer terminating unit 508 is terminated. The content indicating the disconnection of the link on the line side is set in the register. As a result, the control unit 512 switches from the UNR packet to the SEND-UNR packet, and transfers this to the optical conversion bridge 60 from the optical fiber transmission line 40 via the relay device 70 in the same manner as above. At that time, in the first and second relays 80 and 90 of the relay device 70, "0001" is added to the identification code ID of the SEND-UNR packet, and a value indicating the passage is added. As a result, in the optical conversion bridge 60, when the control unit 612 continuously detects, for example, two SEND-UNR packets by sampling every one second, the optical conversion repeater 50 outputs an optical conversion signal together with a warning indicating the disconnection of the user side link. An alarm indicating disconnection of the line link in the repeater 50 is generated from the alarm output and is notified to the outside.

Thereafter, the respective failures are removed, the user side link and the line link in the optical conversion repeater 50 are respectively restored, and the Ethernet frame from the user LAN 10 is supplied to the electrical physical layer terminating unit 502.
Also, the optical fiber transmission line 40
When there is a frame input from, the contents of the link disconnection of the internal registers of the physical layer termination units 502 and 508 are released. As a result, the control unit 512 stops the transmission of the UNR packet or the SEND-UNR packet.
As a result, the control unit 612 of the optical conversion bridge 60 confirms, for example, that the UNR packet is not detected four times in succession or that the SEND-UNR packet is not detected four times in succession by sampling every second. Then, the alarm output indicating the disconnection of the link on the user side and the alarm output indicating the disconnection of the line link in the optical conversion repeater 50 are released and the normal frame transfer state is restored.

In addition, from the optical conversion repeater 50 to the relay device 7
When a failure occurs in the optical fiber transmission line 40 to 0, the frame input from the optical fiber transmission line 40 to the first repeater 80 of the relay device 70 is stopped. In this case, the first
In the repeater 80 of, like the case of the optical conversion repeater 50,
When the internal register is set to the link disconnection in the optical physical layer terminating unit 802 and this is detected by the control unit 812,
SEND packets indicating disconnection on the user side are sequentially generated at predetermined intervals and are supplied to the changeover switch 822 of the alarm packet insertion unit 806. At this time, an identification code such as "0001" indicating the device identification is added to the pattern PT indicating the SEND packet. Changeover switch 8
The SEND packet supplied to 22 is sequentially inserted in the outgoing route from the alarm packet inserting unit 806 to the electrical physical layer terminating unit 808, and further from the electrical physical layer terminating unit 808 via the electrical transmission path 300 to the relay device 70. 2 is transferred to the repeater 90.

Next, from the first repeater 80 to the electric transmission line 3
Second repeater 9 that receives a SEND packet via 00
In 0, when the alarm packet detection unit 904 detects the SEND packet from the outward route from the electrical physical layer termination unit 902 to the optical physical layer termination unit 908, the SEND packet is supplied to the control unit 912 as described above. In the control unit 912 that has received the SEND packet, the identification code generation unit 942 detects the identification code “0001” and adds “0001” to this.
That is, "1" is added and the value is set to "0010". The SEND packet to which the identification code is added is inserted by the alarm packet inserting unit 906 on the outward route to the optical physical layer terminating unit 908, and is further transferred to the optical conversion bridge 60 via the optical fiber transmission line 40. As a result, in the optical conversion bridge 60, similarly to the above, the values of the alarm packet pattern PT and the identification code ID are determined, and the relay device 7
The SEND packet from the first repeater 80 of 0 is identified, and the result is reported to the outside similarly to the above. Further, when the first repeater 80 transmits the SEND packet and the link break on the electric transmission path 300 side is detected, the SEND-UNR packet is generated and the second repeater 90 is passed through as in the above. And transmits it to the optical conversion bridge 60. As a result, the optical conversion bridge 60 further detects an abnormality of the electric transmission path 300 in the relay device 70 and notifies the abnormality to the outside. After that, if each line is restored, SEND-UNR packet or S
The END packet is stopped, and the normal state is restored as described above.

When the second repeater 90 of the repeater detects a failure in the electric transmission path 300 or the optical fiber transmission path 40 from the first repeater 80, the UNR packet is transmitted in the same manner as above. Alternatively, a SEND-UNR packet is generated and transmitted to the optical conversion bridge 60 via the optical fiber transmission line 40. In this case, the alarm packet does not pass through the host device but is directly transferred to the optical conversion bridge 60, and the value of the identification code ID is “0001”. As a result, it is determined that the packet is the UNR packet or the SEND-UNR packet from the second relay 90, the transmission path failure in the second relay 90 is identified, and the result is broadcast to the outside.

Further, when a failure occurs in the optical fiber transmission line 40 from the second repeater 90 to the optical conversion bridge 60, the optical fiber transmission line 40 to the optical conversion bridge 60.
The frame input to the optical physical layer terminating unit 602 is stopped.
As a result, when the optical physical layer terminating unit 602 ceases to detect a signal due to a frame input, the content indicating the line link disconnection is set in its internal register. Upon detecting this, the control unit 612 generates an alarm indicating the disconnection of the line link in its own device from the alarm output and notifies the outside. afterwards,
When the line link is restored, the optical physical layer terminating unit 602 detects the current waveform corresponding to the frame input, and the content indicating the link disconnection of the internal register is released. As a result, the alarm output indicating the line link disconnection from the control unit 612 is released, and the normal frame transfer state is restored.

On the other hand, the wide area LAN 20 to the user LAN 1
The Ethernet frame addressed to 0 is the optical conversion bridge 60.
From the optical fiber transmission lines 40, 40 via the relay device 70
Is supplied to the optical conversion repeater 50 and is further transferred from the optical conversion repeater 50 to the user LAN 10. In this case, for example, when a failure occurs in the optical fiber transmission line 40 from the relay device 70 to the optical conversion repeater 50, the optical physical layer termination unit 50 of the optical conversion repeater 50 from the optical fiber transmission line 40.
The frame input to 8 is stopped and the signal is no longer detected. As a result, the optical physical layer terminating unit 508 sets the internal register to the link disconnection. When this is detected by the control unit 512, SEND packets representing the line link disconnection in the optical conversion repeater 50 are sequentially generated at predetermined intervals, and the changeover switch 520 of the alarm packet insertion unit 506 is generated.
Is supplied to. SEN supplied to changeover switch 520
The D packet is sequentially inserted on the outward route from the MAC switch 504 to the optical physical layer terminating unit 508, and is further converted from electrical to optical in the optical physical layer terminating unit 508 to be optically transmitted from the optical fiber transmission line 40 via the relay device 70. Each is transmitted to the conversion bridge 60.

The SEND packet transmitted to the optical conversion bridge 60 via the optical fiber transmission line 40 has its identification code ID in the first and second repeaters 80 and 90 of the repeater, as described above. It is an added value representing the passage of. As a result, the optical conversion bridge 60
Is photo-electrically converted in the optical physical layer terminating unit 602 of
SEND forwarded to MAC switch 606
The packet is the detection line 620 of the alarm packet detection unit 604.
And is sequentially supplied to the control unit 612 via. At this time, SE
Although the ND packet is also input to the MAC switch 606 from the outward route, since the SEND packet is shorter than the packet length of the Ethernet frame normally transferred, the MAC switch 606 discards the SEND packet as an abnormal packet. On the other hand, when the control unit 612 detects the SEND packet by sampling every one second, for example, twice in succession, the alarm pattern PT and the identification code are respectively determined to indicate the line link disconnection in the optical conversion repeater 50. An alarm is generated from the alarm output. This result is notified to the outside by the alarm device as in the above.

In the above case, the optical fiber transmission line 4
If the line between the optical conversion repeater 50 and the user LAN 10 is disconnected after the link is disconnected from 0 to the optical conversion repeater 50, or at the same time, the electro-physical layer termination unit 50.
In 2, the contents indicating the disconnection of the link on the user side are set in the internal register. As a result, the control unit 512 causes the SE
The ND packet is switched to the SEND-UNR packet, and the packet is transferred to the optical conversion bridge 60 by the optical fiber transmission line 40 via the relay device 70 as described above. As a result, in the optical conversion bridge 60, when the control unit 612 detects, for example, two consecutive SEND-UNR packets by sampling every one second, it determines the alarm pattern PT and the identification code ID, respectively, and performs optical conversion. An alarm indicating disconnection of the line link in the repeater 50 and an alarm indicating disconnection of the link on the user side are generated from the alarm output, and the alarm is externally notified.

After that, when the line link to the optical conversion repeater 50 and the user side link are respectively restored, the Ethernet frame from the optical conversion bridge 60 is supplied to the optical physical layer terminating unit 508 of the optical conversion repeater 50, and the electrical physical layer is further supplied. When the terminating unit 502 receives a frame input from the user LAN 10, the respective physical layer terminating units 502, 5
The contents indicating the disconnection of the internal register 08 are released. As a result, the control unit 512 stops the transmission of the SEND packet or the SEND-UNR packet. As a result, in the control unit 612 of the optical conversion bridge 60, for example, the SEN is continuously performed four times by sampling every one second.
When the non-detection of the D packet or the SEND-UNR packet is confirmed, the alarm output indicating the line link disconnection and the alarm output indicating the user side link disconnection in the optical conversion repeater 50 are canceled to restore the normal frame transfer state. To do.

Further, when a transmission line failure or the like occurs between the wide area LAN 20 and the optical conversion bridge 60, the frame input to the electrophysical layer termination unit 608 of the optical conversion bridge 60 is stopped. As a result, the electrical physical layer termination unit 60
In No. 8, when the signal detection by the frame input disappears, the content indicating the link disconnection is set in the internal register. Upon detection of this, the control unit 612 issues an alarm indicating the station side link disconnection from the alarm output and notifies the outside. After that, when the station side link is restored, the electrical physical layer termination unit 608
At, the current waveform corresponding to the frame input is detected, and the content indicating the disconnection of the internal register is released. As a result, the alarm indicating the office side link disconnection from the control unit 612 is released, and the normal frame transfer state is restored.

On the other hand, when power failure occurs in the optical conversion repeater 50 due to a failure of the input power source or the like, the control unit 512, which detects this, sequentially generates R-INH packets indicating power failure, and issues an alarm as described above. Data is transmitted from the packet inserting unit 506 to the optical conversion bridge 60 via the optical physical layer terminating unit 508 and the optical fiber transmission line 40 via the repeater 70. R- from the optical conversion repeater 50
In the optical conversion bridge 60 which has received the INH packet, the optical physical layer terminating unit 60 detects this by the alarm packet detection unit 604.
It is detected from the outgoing route from 2 to the MAC switch 606 and sequentially supplied to the control unit 612. Accordingly, the control unit 612
Then, when the R-INH packet is detected, for example, twice in succession, the alarm pattern PT and the identification code ID are determined, and an alarm indicating that the optical conversion repeater 50 is powered off is generated from the alarm output and is output to the outside. Notify me. After that, when the power is restored in the optical conversion repeater 50, R-INH
The packet transmission is stopped and then an R-INH release packet is generated and transmitted like any other alarm packet. When the R-INH packet is stopped, the control unit 612 of the optical conversion bridge 60 confirms that the packet is not detected, and when the R-INH release packet is received, the detection of another alarm is stopped for 2 seconds, and the line is stopped. Wait for link recovery. When the line link is restored, the alarm output indicating the power failure in the optical conversion repeater 50 is released and the normal frame transfer state is restored.

Similarly, when power is cut off in each of the repeaters 80 and 90 of the repeater 70, as in the case of the optical conversion repeater 50, the respective control section 812 or 91.
2 generates an R-INH packet and transfers it to the optical conversion bridge 60. In this case, the R-INH packet from the first relay 80 is transmitted to the second relay 90 similarly to the above.
, The identification code ID is added, and "001
0 ”and transferred to the optical conversion bridge 60. The R-INH packet from the second repeater 90 is supplied to the optical conversion bridge 60 with the value of the identification code ID being “0001”. As a result, which device the R-INH packet is from is determined, and the result is notified.
By the way, the identification code of the R-INH packet from the optical conversion repeater 50 becomes “0011” and is supplied to the optical conversion bridge 60.

As described above, according to the LAN-to-LAN connection system and its alarm transfer method of the present embodiment, the inexpensive optical conversion bridge 60 and optical conversion repeater 50 are used.
And the first and second repeaters 80 of the repeater 70,
Wide area LA of the telecommunications carrier through the optical fiber transmission lines 40, 40 via the relay station 30 from the user LAN 10 using 90.
It is possible to effectively connect to N20. In this case, when an abnormality such as a link disconnection is detected in the optical conversion repeater 50 inside the home or the first or second repeater 80, 90 of the repeater 70, the station is notified by using an alarm packet indicating each abnormality. The alarm can be effectively transferred to the optical conversion bridge 60 on the side, and the abnormality can be accurately notified to the administrator. In particular, since the warning packet is shorter than the shortest packet length of a normal Ethernet frame, the warning packet of the broadcast address is discarded by the MAC switch 606 after being detected by the control unit 612, so that the wide area LAN 20 is further extended. It is possible to perform reliable alarm transfer that does not leak to other networks and does not adversely affect other traffic. Therefore, the optical fiber transmission line 40 and the repeater 8
It is possible to quickly detect 0, 90, a failure of the optical conversion repeater 50 inside the home, and the like to improve the quality of maintenance management thereof, and to provide an excellent service to the user. Further, the alarm packet is provided with an identification code ID, and the first and second repeaters 80 and 90 at the relay point 30 add predetermined values to the identification code IDs of the alarm packets from the lower-level devices, respectively, and the device itself. Since it is indicated that the alarm packet has been passed, it is possible to determine which device the alarm packet is from in the optical conversion bridge 60 on the side of the communication carrier. It is possible to accurately and swiftly determine what kind of obstacle in the. Therefore, especially in the case of long distance transmission, the quality of maintenance management can be further improved.

In the above embodiment, the optical fiber transmission line 40 having the transmission band of 100 Mbps is applied, but of course, the optical fiber transmission line 40 having the arbitrary transmission band may be applied. Further, in the above embodiment, the case where only one relay point is provided has been described as an example, but the present invention can of course be applied to the case where there are a plurality of relay points.

In the above embodiment, a case has been described as an example where a packet shorter than the shortest packet length of an Ethernet net frame transferred in a normal LAN is applied as an alarm packet and discarded in the optical conversion bridge 60. In the present invention, the alarm packet is LA
Any shape or any format may be used as long as it is effectively discarded without flowing out to the N side. For example, as shown in FIG. 11, an alarm packet is formed to have the same data length as an ordinary Ethernet frame to which an alarm pattern and an identification code are added, and a packet in which an error is forcibly inserted is generated as the error correction code. It may be transferred.

[0065]

As described above, according to the LAN-to-LAN connection system of the present invention, the LAN connecting the user LAN and the wide area LAN of the communication carrier by the optical fiber transmission line via at least one or more relay points. A first conversion device, which is a connection system, is installed in a user's house, and converts a data frame transmitted between a user LAN and an optical fiber transmission line into an electric-optical signal and transfers the data frame by medium access control. A second conversion device which is installed on the communication carrier side and which electro-optically converts a predetermined data frame to be transmitted between the wide area LAN and the optical fiber transmission line and transfers the data frame by medium access control, A relay device including first and second relays installed at respective relay points of an optical fiber transmission line and connected to each other by an electric transmission line, A relay device for converting a data frame from the fiber transmission line into an electric signal, converting it again into an optical signal to be transmitted by the optical fiber transmission line, and transferring the same. The second repeater monitors the input / output state of the data frame to / from its own device, and when it detects an abnormality, it is an alarm packet indicating each abnormality and is an alarm that is discarded by the second converter. Alarm transfer control means for transferring the packet to the second converter via an optical fiber transmission line including a relay point or another relay is included, and the first and second relay devices are further included.
When the alarm packet transferred from the first conversion device or the first conversion device to the second conversion device passes through its own device, the relay device of the above-mentioned relay device adds an identification code indicating the passage of the own device to the alarm packet. The second optical conversion device receives an alarm packet from the first optical conversion device or the first repeater or the second repeater of the repeater device from the optical fiber transmission line, and receives the alarm packet from the optical fiber transmission line. It is determined whether the alarm packet is from the first optical conversion device or the first or second repeater of the repeater device, and it is further judged as abnormal and the alarm represented by the alarm packet is output to the outside. And an alarm output control means for controlling the output, the abnormality detected in the first conversion device inside the home or the first or second repeater of the relay device is effectively transferred to the second conversion device on the telecommunications carrier side. Can That it is possible to realize a LAN connecting inexpensive bridge type.

According to the LAN-to-LAN connection system of the second aspect of the present invention, the alarm packet is a packet formed to have a packet length shorter than the shortest packet length of the data frame to be transferred and processed in the second converter. There
At least a predetermined pattern representing the type of alarm and a first pattern
And a predetermined identification code indicating whether the alarm packet is generated from the converter of the second converter or the first or second relay of the relay. Depending on the length, it can be effectively distinguished from the data frame transferred to the LAN and discarded. Therefore, it is possible to effectively prevent the resulting communication disruption without transferring useless packets to the LAN.

According to the LAN-to-LAN connection system of the third aspect of the present invention, the alarm packet is a packet having the same length as the packet length of the data frame to be transferred and processed in the second converter, and at least the alarm packet. A predetermined pattern indicating the type, an identification code indicating whether the alarm packet is generated from the first conversion device or the relay device, and an error correction code of the alarm packet that is compulsorily applied to the code. Since the error correction code including the error is included, the alarm packet can be effectively distinguished from the data frame transferred to the LAN by the error code and discarded in the second conversion device. Therefore, it is possible to effectively prevent the resulting communication disruption without transferring useless packets to the LAN.

According to the alarm transfer method of the fourth aspect of the present invention, the first converter and the first and second repeaters of the relay device add a code having the same value as the identification code to the alarm packet. Since the first and second relays of the relay device add the predetermined value to the identification code when the alarm packet transferred from each device passes through the own device, the first and second relays transfer the alarm packet. It is possible to effectively determine from which device the alarm packet is transferred in the second conversion device. In this case, in the first and second repeaters,
A simple adder circuit can be used as the identification code assigning means, and the circuit can be realized with a simple configuration.

According to the alarm transfer method of claim 5 of the present invention, the first conversion device is connected to the electrical physical layer terminating means for terminating the electrical physical layer connected to the user LAN, and is connected to the optical fiber transmission line. An optical physical layer terminating means for terminating the optical physical layer, a MAC switch for transferring a data frame between the terminating means according to its MAC address, and M
An alarm packet inserting means for inserting an alarm packet from the alarm transfer control means into the transmission path to the optical fiber transmission line between the AC switch and the optical physical layer terminating means, and the alarm transfer control means at least the electric physical layer. The first monitoring means for monitoring the link state with the user LAN in the terminating means, the second monitoring means for monitoring the link state with the optical fiber transmission line in the optical physical layer terminating means, and the power supply of the own device Since the third monitoring means for monitoring whether or not the operation is normal and the packet generation means for generating an alarm packet representing the abnormality when any of the respective monitoring means detects an abnormality, the user's premises Failure of the user side link or line side link or power failure of its own device is accurately detected, and an alarm packet indicating those failures is sent to the second conversion device on the business side. It can be transferred to the effect.

According to the alarm transfer system of claim 6 of the present invention, the first and second relays of the relay device are respectively
Electrical physical layer termination means for terminating the electrical physical layer connected to the electrical transmission path, optical physical layer termination means for terminating the optical physical layer connected to the optical fiber transmission path, and alarm transfer control means between the termination means. Alarm packet inserting means for inserting the alarm packet from the device into the transmission path to the second conversion device,
Alarm packet detecting means for detecting an alarm packet from the first conversion device or the first repeater from the receiving path between the terminating means, and the alarm transfer control means at least the electrical transmission in the electrical physical layer terminating means. First monitoring means for monitoring the link status with the optical path, second monitoring means for monitoring the link status with the optical fiber transmission path at the optical physical layer terminating means, and whether or not the power supply of the own device is normal Third to monitor
Monitoring means and packet generating means for generating an alarm packet indicating the abnormality when any of the monitoring means detects an abnormality, and the identification code assigning means detects the abnormality by the alarm packet detecting means. In the relay point in long-distance transmission, it includes addition means for adding a predetermined value to the identification code of the alarm packet from the converter or the first repeater to generate an identification code indicating that the alarm packet has passed through the own apparatus. Of the user side link or line side link or the power failure of its own device is accurately detected, and the alarm packet indicating the fault and the device identification can be effectively transferred to the second conversion device on the operator side. it can. .

According to the alarm transfer system of claim 7 of the present invention, the second conversion device is connected to the electrical physical layer terminating means for terminating the electrical physical layer connected to the wide area LAN, and the optical fiber transmission line. The optical physical layer terminating means for terminating the optical physical layer that has been terminated, and the data frame between the terminating means.
MAC switch that transfers according to AC address, and MA
Alarm packet detecting means for supplying an alarm packet from the first converter or the first or second repeater of the repeater between the C switch and the optical physical layer terminating means to the alarm output control means from its reception path; The alarm output control means includes at least an identification code determination means for determining whether the alarm packet from the alarm packet detection means is the alarm packet from the first conversion device or the relay device, and Since it includes the alarm determination means for determining which of the abnormalities of the above and the alarm generation means for generating an alarm based on the result thereof, the optical conversion repeater on the inside of the home or the first or the second at the relay point is included. It is possible to accurately detect the alarm packets from the repeater and effectively notify the outside of the abnormality such as the transmission path represented by the alarm packets. Particularly, since the alarm packet is formed differently from the normal frame, the MAC switch blocks the alarm packet from passing to the wide area LAN side and discards it, so that the outflow of the alarm packet does not cause any adverse effect.

According to the alarm transfer method of claim 8 of the present invention, an inter-LAN connection system for connecting a user LAN and a wide area LAN of a communication carrier via an optical fiber transmission line including at least one or more relay points. And a first conversion device for converting the data frame transmitted between the user LAN and the optical fiber transmission path inside the user's house into an electric-optical signal and transferring the data frame by medium access control. Prepare a second converter for the communication carrier to electro-optically convert a predetermined data frame to be transmitted between the wide area LAN and the optical fiber transmission line and transfer the data frame by medium access control. , A relay device including first and second repeaters connected to each relay point by an electric transmission line, and data from the optical fiber transmission line. A relay device for temporarily converting the frame into an electric signal and then converting the frame into an optical signal to be transmitted through an optical fiber transmission line and transferring the optical signal is prepared. The input states of the data frames from the fiber transmission line are monitored, and the input states of the data frames from the optical fiber transmission line or the electric transmission line are monitored at the first and second repeaters of the relay device, respectively. When an anomaly is detected during the monitoring of an alarm packet, an alarm packet that represents each anomaly and is discarded by the second conversion device is generated, and the alarm packet is transmitted to an optical source including a relay point or another relay. It transmits to a 2nd conversion apparatus via a fiber transmission line, at that time, in a relay place, from a 1st conversion apparatus or a 2nd repeater. When the alarm packet passes through its own device, an identification code indicating the passage is added and transferred, so that a failure detected by the first converter inside the house or the first or second repeater of the repeater, etc. Can be effectively transferred to the second conversion device on the business operator side. In particular, it is possible to easily discriminate which device the packet is from by giving an identification code indicating that the alarm packet from the lower-level device has passed. Further, since the alarm packet is formed in a shape different from that of a normal data frame packet, it does not pass from the optical conversion bridge to the wide area LAN side, and the alarm is effectively transferred without adversely affecting other communication. can do.

According to the alarm transfer method of the tenth aspect of the present invention, the second conversion device transmits the alarm packet from the first conversion device or the first or second repeater of the relay device by optical fiber transmission. The first warning packet received from the road
Of the conversion device or the first or second repeater of the relay device and the abnormality thereof, the alarm packet is discarded, and the alarm packet is further expressed by the determination result of the alarm packet. The alarm that is output is output to the outside for notification, so that it is effectively used by the station manager or the like for the first conversion device or the first or second relay device inside the home.
It can notify you of an abnormality in the repeater.

According to the alarm transfer method of the eleventh aspect of the present invention, the alarm packet is a packet formed to have a packet length shorter than the shortest packet length of the data frame to be transferred and processed in the second conversion device. The second conversion device determines the packet length of the alarm packet and discards it as an abnormal packet from the length, so that unnecessary packets are prevented from flowing into the LAN, and the resulting communication confusion is prevented. It can be effectively prevented.

According to the alarm transfer method of the twelfth aspect of the present invention, the alarm packet is a packet having the same length as the packet length of the data frame to be transferred and processed in the second converter, and its error correction is performed. This is a packet in which the code is forcibly included in error, and the second conversion device determines an error in the alarm packet, determines that it is an abnormal packet from the result, and discards it. The inflow can be prevented, and the resulting communication disruption can be effectively prevented.

According to the alarm transfer method of the thirteenth aspect of the present invention, the first converter and the first and second repeaters of the relay device further determine whether or not the power source of the device itself is normal. When an abnormality is detected and an alarm packet indicating the alarm is generated and transmitted to the second conversion device via the optical fiber transmission line, the optical conversion repeater or relay point inside the home is monitored. It is possible to effectively inform the business operator side of a device failure due to the power interruption at the first or second repeater.

[Brief description of drawings]

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

FIG. 2 is a functional block diagram showing an internal configuration example of an optical conversion repeater applied to the inter-LAN connection system according to the embodiment of FIG.

FIG. 3 is a functional block diagram showing an internal configuration example of an optical conversion bridge applied to the inter-LAN connection system according to the embodiment of FIG.

FIG. 4 is a diagram showing a network configuration example to which the inter-LAN connection system according to the embodiment of FIG. 1 is applied.

5 is a functional block diagram showing a functional configuration example of a control unit of the optical conversion repeater applied to the embodiment of FIG.

FIG. 6 is a functional block diagram showing a functional configuration example of a control unit of the optical conversion bridge according to the embodiment of FIG.

7 is a functional block diagram showing a functional configuration example of control units of first and second repeaters applied to the embodiment of FIG. 1. FIG.

8 is a diagram showing a format example of an Ethernet frame applied to the embodiment of FIG.

9 is a diagram showing a format example of an alarm packet applied to the embodiment of FIG.

10 is a diagram showing an alarm transfer method applied to the embodiment of FIG.

FIG. 11 is a diagram showing another format example of an alarm packet applied to the LAN-to-LAN connection system according to the present invention.

[Explanation of symbols]

10 user LAN 20 wide area LAN 30 relay points 40 optical fiber transmission line 50 optical conversion repeater 60 optical conversion bridge 70 Repeater 80 First Repeater 90 Second repeater 100 home router 200 internal router 300 electrical transmission lines 502, 608, 808, 902 Electrophysical layer termination unit 504,606 MAC switch 506 Warning packet insertion unit 520, 622, 822, 922 selector switch 522, 620, 820, 920 Detection line 604 Alarm packet detector 804,904 Alarm packet detector 806, 906 Warning packet insertion unit 508, 602, 802, 908 Optical physical layer termination unit 510, 610, 810, 910 Power supply section 512, 612, 812, 912 control unit

Continued front page    (72) Inventor Yoshihiro Kikukawa             2801 Tawara, Tawara, Mashiki-machi, Kamimashiki-gun, Kumamoto Prefecture               Kyushu Ando Electric Co., Ltd. (72) Inventor, Hisatsu Ikeya             529-3 Kamata, Ota-ku, Tokyo Andoden             Ki Co., Ltd. F term (reference) 5K028 AA14 BB08 CC06 DD04 KK32                       MM08 MM14 PP04 PP22 QQ02                       RR04 TT05                 5K033 AA06 CB08 CC01 DA06 DB04                       DB19 DB22 EA06 EA07 EC01                       EC03

Claims (12)

[Claims] 1. A user LAN and a wide area LAN of a telecommunications carrier
Is a LAN-to-LAN connection system for connecting an optical fiber transmission path via at least one or more relay points, the system being installed in a user's home and transmitting data between the user LAN and the optical fiber transmission path. A first conversion device for converting a frame into an electric-optical signal and transferring the data frame by medium access control, and a predetermined data frame installed on the communication carrier side for transmission between a wide area LAN and an optical fiber transmission line. A second conversion device for converting the data into electric-optical data and transferring the data frame under medium access control, and first and first conversion devices installed at the respective relay points of the optical fiber transmission line connected to each other by the electric transmission line. A repeater including two repeaters, wherein a data frame from the optical fiber transmission line is once converted into an electrical signal and transmitted again through the optical fiber transmission line. And a relay device for converting and converting the optical signal into an optical signal to be transferred, and the first conversion device and the first and second repeaters of the relay device respectively monitor an input / output state of a data frame to the own device. Then, when the abnormality is detected, an alarm packet indicating the respective abnormality, which is discarded by the second conversion device, is transmitted through the optical fiber transmission line including a relay point or another relay. Alarm transfer control means for transferring to a second conversion device, wherein the first and second relays of the relay device are from the first conversion device or the first relay device to the second conversion device. When the alarm packet to be transferred passes through the device itself,
The alarm packet includes an identification code assigning means for assigning an identification code indicating the passage of the device itself, wherein the second optical conversion device is the first optical conversion device or the first repeater or the first repeater of the relay device. The alarm packet from the second repeater is received from the optical fiber transmission line, and it is determined whether the alarm packet is from the first optical conversion device or the first or second repeater of the repeater. And an alarm output control means for determining an abnormality and outputting an alarm represented by the alarm packet to the outside. 2. The LAN-to-LAN connection system according to claim 1, wherein the alarm packet is a packet formed to have a packet length shorter than a shortest packet length of a data frame to be transferred and processed in the second conversion device. And at least a predetermined pattern indicating the type of alarm and a predetermined identification code indicating which device is generated from the first conversion device or the first or second repeater of the relay device. An inter-LAN connection system characterized by including packets. 3. The inter-LAN connection system according to claim 1, wherein the alarm packet is a packet having a length similar to a packet length of a data frame to be transferred and processed in the second conversion device, and at least the alarm is issued. A predetermined pattern indicating the type of the alarm packet, an identification code indicating whether the alarm packet is generated from the first conversion device or the relay device, and an error correction code of the alarm packet An inter-LAN connection system comprising a packet including an error correction code forcibly including an error. 4. The LAN according to claim 2 or 3.
In the inter-connection system, the first conversion device and the first and second relays of the relay device add a code having the same value as an identification code to an alarm packet and transmit the alarm packet. The second repeater is an inter-LAN connection system characterized in that when an alarm packet transferred from each device passes through its own device, a predetermined value is added to its identification code and transferred. 5. The inter-LAN connection system according to any one of claims 1 to 4, wherein the first conversion device includes an electrical physical layer terminating unit that terminates an electrical physical layer connected to a user LAN. , An optical physical layer terminating means for terminating an optical physical layer connected to an optical fiber transmission line, a MAC switch for transferring a data frame between the terminating means according to its MAC address, the MAC switch and the optical physical layer terminating means And an alarm packet insertion unit that inserts an alarm packet from the alarm transfer control unit into a transmission path to an optical fiber transmission line, the alarm transfer control unit including at least the electrical physical layer termination unit. A first monitoring means for monitoring the link status with the user LAN, and a first monitoring means for monitoring the link status with the optical fiber transmission line at the optical physical layer termination means. The second monitoring means, the third monitoring means for monitoring whether or not the power source of the own device is normal, and when an abnormality is detected in any of the respective monitoring means, an alarm packet representing the abnormality is generated. An inter-LAN connection system comprising a packet generation means. 6. The inter-LAN connection system according to claim 1, wherein the first and second relays of the relay device each include an electrical physical layer connected to an electrical transmission line. The electrical physical layer terminating means for terminating, the optical physical layer terminating means for terminating the optical physical layer connected to the optical fiber transmission line, and the alarm packet from the alarm transfer control means between the terminating means and the second conversion. An alarm packet inserting means for inserting the alarm packet into the transmission path to the device; and an alarm packet detecting means for detecting an alarm packet from the first converting device or the first repeater from the receiving path between the terminating means, The alarm transfer control means is at least a first monitoring means for monitoring a link state with the electric transmission line in the electric physical layer terminating means, and an optical fiber transmission in the optical physical layer terminating means. The second to monitor the link status with the road
Monitoring means, a third monitoring means for monitoring whether the power source of the device itself is normal, and a packet for generating an alarm packet indicating the abnormality when an abnormality is detected in any of the monitoring means. Generating means, and the identification code assigning means adds a predetermined value to the identification code of the alarm packet from the first converter or the first repeater detected by the alarm packet detecting means and adds its own value. An inter-LAN connection system including an adding means for generating an identification code indicating that the LAN has passed. 7. The inter-LAN connection system according to claim 1, wherein the second conversion device is an electrical physical layer terminating unit that terminates an electrical physical layer connected to a wide area LAN. , An optical physical layer terminating means for terminating an optical physical layer connected to an optical fiber transmission line, a MAC switch for transferring a data frame between the terminating means according to its MAC address, the MAC switch and the optical physical layer terminating means And an alarm packet detecting means for supplying an alarm packet from the first conversion device or the first or second repeater of the relay device to the alarm output control means from its reception path. The output control means is configured such that at least the alarm packet from the alarm packet detection means is transmitted from either the first conversion device or the relay device. Identification code determining means for determining whether the packet is an alarm packet, alarm determining means for determining which abnormality in the device is represented, and alarm generating means for issuing an alarm based on the result thereof. A LAN-to-LAN connection system characterized by: 8. A user LAN and a wide area LAN of a telecommunications carrier
An alarm transfer method in an inter-LAN connection system for connecting a LAN via an optical fiber transmission path including at least one relay point, the data frame being transmitted between the user LAN and the optical fiber transmission path inside the user's house. A first conversion device for converting the data into an electric-optical signal and transferring the data frame by medium access control is prepared, and a predetermined data frame to be transmitted between the wide area LAN and the optical fiber transmission path is electrically converted to the communication carrier side. A second conversion device for optically converting and transferring the data frame by means of medium access control is prepared, and further, the first and second devices connected to the respective relay points by electric transmission lines.
And a relay device for converting the data frame from the optical fiber transmission line into an electric signal, converting the data frame into an optical signal to be transmitted again through the optical fiber transmission line, and transferring the optical signal. 1 conversion device, at least the user LAN
The input state of the data frame from the optical fiber transmission line and the input state of the data frame from the optical fiber transmission line are respectively monitored, and at the first and second repeaters of the relay device, the data from the optical fiber transmission line or the electric transmission line is monitored. The input states of the frames are respectively monitored, and when an abnormality is detected in these cases, an alarm packet representing the respective abnormality, which is discarded by the second conversion device, is generated, and the alarm packet is generated. The packet is transmitted to the second conversion device via an optical fiber transmission line including a relay point or another relay, and at the relay point, the first conversion device or the first relay or other When an alarm packet from a relay station of the above passes through its own device, an identification code indicating the passage is added and transferred. Alarm transfer method in the arm. 9. The alarm transfer system according to claim 8, wherein the second conversion device transmits an alarm packet from the first conversion device or the first or second repeater of the relay device to an optical fiber. After receiving from the transmission line, determining whether the alarm packet is from the first conversion device or the first or second repeater of the relay device and determining the abnormality, An alarm transfer method in a LAN-to-LAN connection system, characterized in that an alarm packet is discarded, and an alarm represented by the determination result of the alarm packet is output and notified to the outside. 10. The inter-LAN connection system according to claim 9, wherein the alarm packet is a packet formed to have a packet length shorter than a minimum packet length of a data frame to be transferred and processed in the second conversion device. In this connection, the second conversion device determines the packet length of the alarm packet and discards it as an abnormal packet based on the length, and the inter-LAN connection system. 11. The inter-LAN connection system according to claim 9, wherein the alarm packet is a packet having a length similar to a packet length of a data frame to be transferred and processed by the second conversion device, and an error thereof is generated. A LAN-to-LAN connection characterized in that the correction code is a packet forcibly including an error, and the second conversion device determines an error in the alarm packet, determines that it is abnormal from the result, and discards it. system. 12. The alarm transfer system according to claim 8, wherein the first conversion device and the first and second repeaters of the relay device are further powered by their own power source. It monitors whether it is normal, and when it detects an abnormality, it generates an alarm packet representing the alarm,
An alarm transfer method in an inter-LAN connection system, characterized in that this is transmitted to the second conversion device via an optical fiber transmission line.