JPH0690236A - Inter-lan connection control system - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is a LAN in which a plurality of broadband switches are connected.
The semi-fixed connection means (PVC) in which the inter-connection device is preset with the connection with the subscriber and the connection with the other inter-LAN connection device.
It is an object of the present invention to provide an inter-LAN connection service at high speed while saving the use of the resources of the broadband switching network in the inter-LAN connection control method in the system including. [Structure] When traffic that spans LAN-to-LAN connecting devices occurs, the connection from the LAN-to-LAN connecting device accommodating the activation-source subscriber to the LAN-to-LAN connecting device accommodating the activation-destination subscriber is
Allocate a semi-fixed connection means path. The inter-LAN connecting device accommodating the initiating subscriber forms a path to the inter-LAN connecting device accommodating the initiating subscriber to the broadband switch by the connection means (VC) set by call-by-call, and the path is set. L that accommodates the activation destination subscriber by the
The downlink traffic flowing from the inter-AN connection device to the activation source inter-LAN connection device is transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN-to-LAN connection control system for providing wide-area LAN-to-LAN connection service in a broadband network, and more particularly, a LAN-to-LAN connection device connected to a broadband switching network is connected to a subscriber. And other LAN
The present invention relates to a LAN-to-LAN connection control method in a system that includes a semi-fixed connection means (PVC) whose connection with an inter-connection device is preset by a broadband switching network.

In recent years, the development of a broadband switch has been promoted, and
Research on TM exchanges is being actively conducted toward practical use. Inter-LAN connection service is considered to be one of the most effective applications for such a broadband switch. In the United States, SMDS (Switched Multi-megabit), which is being studied mainly in Bellcore
Data Service) is one of the high-speed LAN connection services.

In order to provide high-speed LAN-to-LAN connection,
Basically, PVC (Per
This can be dealt with by connecting with a manent virtual circuit), but it is necessary to avoid this because the resources inside the broadband switching network are almost exclusively used for LAN-to-LAN connection.

[0004]

2. Description of the Related Art Broadband switching (especially ATM switching) technology has not reached the stage of providing an actual service, but a configuration conceivable when a conventional LAN-to-LAN connection technology is simply applied to a broadband switching network. 10 is shown as a conventional example in FIG.

In FIG. 10, a large number of LAN subscribers are accommodated in each of a large number of LANs a to h, and a subscriber accommodated in each LAN has a wide band when communicating with a subscriber accommodated in another LAN. It connects to a LAN-to-LAN connecting device via a network (ATM network), and connects to a subscriber accommodated in another LAN by the LAN-to-LAN connecting device. Basically, the inter-LAN connecting device is accommodated in the broadband network (ATM network). And B. Can be roughly divided into two configurations.

A. Are all LAN-to-LAN connection devices 100-
102 all LANs (hence all subscribers) ah
Is a full mesh system in which a connection path is formed so that In this case, all the paths between each LAN and the LAN-to-LAN connecting device are performed using paths that are registered in advance as PVCs (including upstream and downstream). The PVC does not perform VC (Virtual Call) which is a procedure for setting up a call, but the logical channel setting to be performed in the call setting is registered in advance in the ATM switch, and if the PVC is set as a communication partner, the call setting is performed. You can communicate immediately without doing. Also, the registered logical channel will not be used as reserved for other call setups.

In this system, a subscriber of a LAN sends L
Information transmitted via the inter-AN connection device is A
In the TM switch, the LAN inter-connection device that handles the most traffic is determined by traffic management, and the information is transferred using the corresponding PVC.
Performs routing based on the other party's address.

B. Each LAN is connected only to the nearest inter-LAN connecting device. In the figure, LANs a to c are connected to the inter-LAN connecting device 100, and LANd and e are connected to the inter-LAN connecting device 10.
1 ... Connected between LANs 10
0 is connected to an adjacent LAN connecting device. Also in this case, the logical channels between the LANs and the LAN-to-LAN connecting devices and the LAN-to-LAN connecting devices are the same as those in the above A. Similarly to the above, the PVC is registered in advance in the ATM network (ATM exchange).

According to this method, data is transferred in sequence from the LAN subscriber of the transmission source to the inter-LAN connecting device accommodating the designated destination, and finally the transfer destination subscriber is accommodated.
Information will be carried to the AN.

[0010]

In the conventional example shown in FIG. In this method, since a large number of PVCs are set up to connect the LAN and the LAN-to-LAN connecting device, most of the resources of the broadband switch (switch and transmission line bandwidth) are dedicated to the LAN-to-LAN connection, and high-speed LAN-to-LAN service is provided. However, there is the problem of affecting VC-based services that use other normal call setup procedures. On the other hand, B. In this method, since the traffic of the LAN-to-LAN connection device is concentrated due to the detour, it is necessary to prepare a thick bundle (large-capacity path) in the broadband network. Although it is not the same as the above method, the resources are monopolized.
Furthermore, since the LAN connecting devices are connected in multiple stages, A. There is a problem that the connection cannot be speeded up compared to.

An object of the present invention is to provide an inter-LAN connection control method capable of providing an inter-LAN connection service at high speed while conserving the use of resources of a broadband switching network.

[0012]

FIG. 1 is a diagram for explaining the principle of the present invention. In FIG. 1, reference numeral 1 is a start-up LAN in which a start-up subscriber is accommodated, 2 is a broadband network, and 3 to 5 are inter-LAN connecting devices for accommodating nearest LANs. In the figure, 3 is a start-up LAN. Inter-LAN connecting device for accommodating 4
Is an inter-LAN connecting device adjacent to the inter-LAN connecting device 3, 5
Is an inter-LAN connecting device accommodating the LAN of the activation destination (partner) subscriber, and 6 is an activation destination LA accommodating the activation destination subscriber.
N.

The present invention relates to the B. Based on
As a means of reducing the resources of the LAN-to-LAN connection device, the path for information (uplink information) from the first activation source is
The inter-AN connection device is sequentially activated by PVC by the activation subscriber L
The path of information (downlink information) connecting from the LAN inter-connector that accommodates the AN to the LAN inter-connector that accommodates the LAN of the initiating subscriber is VC-based (depending on call setup) It is formed by the connection request by.

[0014]

When the subscriber of the source LAN 1 requests a connection with the subscriber accommodated in another LAN as the destination (destination), the source LAN 1 is the LAN closest to the broadband network (ATM switching network) 2. The connection device 3 is connected. The path in this case is registered in advance as PVC. Upon receiving this request, the LAN-to-LAN connecting device 3 checks whether or not the requested LAN is included in the plurality of LANs accommodated in the own device, and if so, the LAN of the starting source and the LAN of the starting destination are included.
Connect. When the LAN 6 of the activation destination is not accommodated in the inter-LAN connecting device 3, the request is transferred using the path of the adjacent inter-LAN connecting device 4 in which the PVC is set. At this time, the inter-LAN connecting device accommodating the LAN of the activation source gives its own address to the transferred information.

In response to this, the adjacent LAN-to-LAN connecting device 4 similarly judges whether or not the LAN to be activated is accommodated in its own device.
The data is transferred via this path. At this time, the address given by the inter-LAN connecting device 3 is transferred without being changed. When it is found that the LAN-to-LAN connecting device 5 accommodates the LAN to be activated, an up and down path is formed between the LAN to be activated and PVC.

Upward information transfer paths from the LAN-to-LAN connecting device 3 to the LAN-to-LAN connecting device 5 to the LAN-to-LAN connecting device 5 are sequentially formed via the PVC as described above. The path for transferring the downlink information from the connection device 5 to the LAN connection device 3 does not use PVC,
Using the address of the LAN inter-connection device 3 (included in the information received via the above-mentioned upward path) from the inter-connection device 5 to the broadband network 2, a call setup request is issued by a normal VC. Then, a VC path is formed as shown in FIG.

LAN receiving this downlink path connection request
Inter-connector 3 (L that first received a request from the activation LAN
When the inter-AN connection device) monitors downlink traffic and determines that there is no traffic for a certain period of time, it issues a disconnection request for the corresponding VC that requested connection and opens the path.
As a result, the capacity occupied by the PVC between the LAN-to-LAN connecting devices can be reduced to B. As described above, the PVC does not have to exclusively occupy the path between the LAN-to-LAN connecting devices for upstream / downstream, the capacity can be reduced to half, and the resource of the broadband network is not wastefully occupied.

This means that in network design,
Since it is necessary to consider that traffic for subscribers not accommodated by one LAN connecting device will flow, a considerable amount of path capacity is required. Also effective. Also, one LAN inter-connector itself can reduce the input / output capacity for connecting the LAN inter-connector. By allocating this amount to the subscriber, LA
It is possible to reduce the number of N-to-N connecting devices themselves. Further, this makes it possible to speed up the inter-LAN connection service.

[0019]

FIG. 2 is a system configuration diagram in which the present invention is implemented,
FIG. 3 is a configuration diagram of LAN data and cells, FIG. 4 is a configuration diagram of an embodiment of an inter-LAN connecting device, FIGS. 5 and 6 are control flows in the inter-LAN connecting device, and FIG. 7 is a configuration diagram of each table.

FIG. 2 shows the system configuration of A. And B. Two forms of are shown. A. Is a form in which one ATM exchange accommodates a plurality of LAN connecting devices to provide services. That is, the ATM switch 2
0, a plurality of LANs are accommodated in the ATM switch 20 by an ATM interface via an ATM compatible brouter (device having a function of a bridge and a router), and the plurality of LAN connecting devices 21-1 ... 21-n are respectively A subordinate LAN is allocated and accommodated in the ATM exchange 20. Each LAN has an upstream / downstream PV as a path for transferring information to / from the assigned inter-LAN connection device.
The C path is registered in the ATM exchange 20.

Further, the LAN connecting devices 21-1 to 21-
For n, a PVC is registered for a path for transferring upstream information that is connected to adjacent LAN connecting devices in order. In addition,
The upstream PVC for one LAN inter-connection device to the other LAN inter-connection device and the upstream PVC for one LAN inter-connection device are registered, but these two paths are between each LAN. They are treated as upstream paths in the connection device and are unrelated to each other.

FIG. 2B. Is a form in which a plurality of inter-LAN connection devices are accommodated in a plurality of ATM exchanges. Only two ATM exchanges 20-1 and 20-2 are shown in the figure, and the other exchanges are not shown, but they are mutually connected by a trunk line. By connecting, it is composed of an arbitrary number of ATM exchanges. LAN connecting devices 21-1 and 21-2 are provided in each ATM exchange, and an arbitrary number of LANs are accommodated in the ATM exchanges connected to each LAN connecting device (in the case of B., the ATM exchange 20- The LAN accommodated in 2 is not shown.

Each LAN has an inter-LAN connecting device and an upstream / downstream PV provided in an ATM switch in which each LAN is accommodated.
Connected by C. Each LAN-to-LAN connecting device has its own device accommodated in the ATM switch, and the LAN-to-LAN connecting device accommodated in the adjacent ATM switch and the upstream path are registered by the PVC. One L from the other LAN connection device
An upstream PVC is registered in the inter-AN connection device.

When an ATM switch requests a logical channel of a PVC registered by an existing technique, it immediately allocates a logical channel to the call to form a path, and when a call setup request by a normal VC is requested, the link is established. A free logical channel by bilink is searched to form a path.

FIG. 3 shows the structure of LAN data and cells.
LAN data transmitted between LANs is shown in a of FIG. 3, and this LAN data is transmitted by a subscriber of the LAN by an ATM compatible brouter as shown in b. (Equipped) and fixed-length cells (or ATM cells) are assembled, and a number of cells corresponding to the data length of LAN data are generated. The information transferred to the LAN subscriber in the form of cells is, when sent from the ATM switch to the LAN subscriber, decomposed into cells as shown in b by an ATM-compatible brouter and excluding the header from the original a. To LAN data such as

FIG. 3C shows a conventional Ethernet frame structure as a specific example of LAN data. in this case,
Destination address (DA: Destination Address) at the beginning, then source address (SA: Source Address), data type (Type), and finally data (length 46 to 1500 bytes)
Are placed. d is the ATM cell format,
The first 5 octets (bytes) are a logical path identifier (VPI: Virtual Path Identifier) and a logical channel identifier (VCI: Virtual Channel Identifier) as shown in the figure.
And a header error control (HEC: Header Error Check), followed by a 48-octet (byte) information field as a payload.

As shown in FIG. 3, LAN data is AT
Inside the ATM switch and L with the ATM switch in the form of M cells
It is transferred between the AN connection devices. Explaining the configuration of the embodiment of the inter-LAN connecting device shown in FIG. 4, reference numeral 40 is the inter-LAN connecting device, and 41 is various kinds of cells (the source and the destination are different).
To the input of VPI / VCI, a separating unit that separates cells according to VPI / VCI, 42 a number of cell receiving buffer units that store cells corresponding to VPI / VCI, and 43 converts the header of the received cell according to the destination A header conversion unit, 44 a multiplexing unit for multiplexing and transmitting a plurality of cells, 45 a supervisory control unit for monitoring received cells, 46 a central control unit, 47 an address conversion table, 48 a cell reception buffer unit Is a header conversion table, and 50 is a VC path setting unit that is driven when setting a downstream path to the LAN connection device of the activation source.

The operation when a LAN data transmission request occurs in the configuration of FIG. 2 will now be described. If the subscriber requesting LAN data transmission sends data, A
Using a TM-compatible brouter, the data chunks in the format shown in FIG.
(Switching network) The VPI and VCI assigned by the administrator are set in the cell header (see d in FIG. 3) and transferred to the ATM switch (at this time, the VCI of the header is from the LAN to the LA).
The VCI of the PVC's logical channel to the N-to-N connection device is not used and is set to 0).

The data transmitted from the LAN subscriber is LA
In each cell input from N, the subscriber and the LAN-to-LAN connecting device are preliminarily connected by PVC in the ATM switch, so this information is transferred to the LAN-to-LAN connecting device.

After that, the operation of the inter-LAN connecting device shown in FIG. 4 will be described below with reference to the control flows shown in FIGS. 5 and 6. Note that S0 at the top of FIG.
The state before the branch is performed by the central control unit 46 of the inter-connection device in response to each event such as a request from each unit or cell reception.

First, in the case of a control flow at the time of receiving a cell (processing after S5), which is a main function of the LAN-to-LAN connecting device, which PVC is added to which LAN by the central control unit 46 of the LAN-to-LAN connecting device 40 of FIG. It is pre-determined which one of the PVC LAN subscribers will use, and which reception buffer each LAN subscriber of each PVC uses is pre-assigned when the LAN-to-LAN connecting device is started up.

Therefore, the cells from the LAN subscriber are sequentially stored in the cell reception buffer section 42 assigned to the PVC included in the cell header in the separation section 41,
At the same time, the copy (image) of the received cell is input to the central control unit 46 by the operation of the read control unit 48 to assemble subscriber information (S5 in FIG. 5). That is, receiving a plurality of cells from the same subscriber, forming data (LAN data excluding header) into one block, and detecting a destination address (DA of c in FIG. 3) in the data, The address conversion table 47 is searched by the address (S6 in FIG. 5).

The address conversion table 47 corresponds to the A. In order to connect to each LAN inter-connection device, the address (displayed as the partner address) of the LAN under its control (the LAN connected to this inter-LAN connection device by PVC) is connected to that LAN, as shown in the configuration example. VPI / VCI (outgoing VP) that represents a logical channel registered as a PVC of
(Displayed as I and outgoing VCI) are stored. The address conversion table 47 also stores information about VCs (described later).

When the address conversion table 47 is searched and the destination address of the received LAN data is detected (YES in S7 of FIG. 5), the VCI of the next received cell is 0. Judge whether or not (Fig. 6
S8). This is to determine whether the received cell is received from the LAN or not (received from another LAN inter-connection device or the like).

When VCI = 0, the destination of this LAN data is the LAN under its control in S7,
The pre-allocated VPI / VCI of the PVC set in the address conversion table 47 is taken out and set in the header conversion table 49 (S14 in FIG. 6). At this time,
VCI is a LAN that the other party accommodates in its own LAN connection device
It is 0 because it is a subscriber. Then, the read control unit 4
8 to request the cells stored in the cell reception buffer unit 42 to be sequentially read (S16).

The header conversion table 49 is the B. As shown in the configuration example, the output VPI and the output VCI are set for each VCI value (input VCI), and the header conversion unit 43 stores the header of the cell read from the cell reception buffer unit 42. When the VCI matches the input VCI of the header conversion table 49, the VPI / VCI of the cell is converted into the corresponding output VPI / output VCI.

As a result, in the configuration of FIG. 4, the header of the read cell is set to the VPI (VPI to the LAN under the own LAN inter-connection device) set in the header conversion table 49 in the header conversion unit 43. After conversion, each cell is sent from the multiplexing unit 44 to the ATM switch to be the LA of the destination.
Sent to N.

Next, in S7 of FIG. 5, when it is determined that the address of the partner LAN is not stored in the address translation table 47, the partner LAN is connected to the L of the partner.
Since the AN subscriber is not accommodated, processing for sending this cell to the next adjacent LAN connecting device is performed.

That is, it is determined whether the input VCI is an inter-LAN connection address (S17 in FIG. 6). At this time, when the activation source LAN is accommodated in the LAN-to-LAN connecting device, since VCI = 0, it is determined to be “NO”. In this case, the LA of its own is added to the output VCI of the header conversion table 49.
The N-to-N connecting device address is set, the VPI for the next LAN connecting device adjacent to the outgoing VPI (the VPI of the PVC for the upstream path) is set (S18 in FIG. 6), and the reading from the cell reception buffer is requested. Yes (at step S16). Therefore, each cell holds the address of the LAN-to-LAN connecting device accommodating the activation LAN as the VCI value of the header and is sent to the next LAN-to-LAN connecting device.

The LAN of the activation source by the above S18 and S16
The cell transmitted from the inter-LAN connecting device is input to the adjacent LAN inter-connecting device, and the destination address is stored in the adjacent LAN inter-connecting device through the determinations in S5 to S7 of FIG.
If it is an AN subscriber, the processes of S8 and S14 in FIG. 6 are performed. If it is not a LAN subscriber of the adjacent LAN connection device, the input VCI is LA in S17 of FIG.
It is determined that the address is the N-to-N connecting device address (in the case of YES), and the process of S19 is performed in order to further transfer the cell of this LAN data to the adjacent LAN-to-LAN connecting device. That is, the VPI value of the next LAN-to-LAN connecting device address is set in the header conversion table 49, and the VCI is the received VC.
I (the address of the inter-LAN connecting device accommodating the activation source LAN) is set as it is, and each cell is read from the reception buffer, the header is converted, and sent to the next inter-LAN connecting device.

Next, in S8 of FIG. 6, VC of the receiving cell
A case where I is determined not to be 0 will be described. In this case, the LAN data transmitted from the inter-LAN connecting device accommodating the above-mentioned activation source LAN is the other inter-LAN connecting device accommodating the destination LAN (including the case where the inter-LAN connecting device for relaying is present). Occurs when received (other cases will be described later).

In this case, if it is determined that the VCI value is the inter-LAN connecting device address in the destination (interacting LAN-containing) LAN connecting device (S9 in FIG. 6), then the ATM switch based on the VCI value. Then, the VC path setting procedure is executed to wait (S10, S11). In this process, since the cell is received by the inter-LAN connecting device accommodating the destination LAN through the upstream path, the VCI (inter-LAN connecting device address accommodating the activation LAN) in the header of the received cell is taken out. , The downlink path (the path from the destination LAN inter-connection apparatus to the activation source LAN inter-connection apparatus) destined for the LAN inter-connection apparatus to the ATM switch
It is requested by the C path call setup procedure.

When the destination LAN-to-LAN connecting device receives the VPI / VCI of the VC obtained by the search in the ATM exchange in response to the call setting request, the address conversion table 4
7, the requester address is set as the partner address (S12 in FIG. 6). These partner addresses, VPI,
The VCI is A.V. V of the address conversion table shown in
It is set in the area for C (for the downlink path).

Next, the empty cell reception buffer unit 42 used by the cell having the corresponding VPI / VCI (downlink cell transmitted from the LAN of the activation destination subscriber) is allocated (S in FIG. 6).
13), the output VPI searched in the header conversion table 49
(V of the path by the PVC that sends the upstream cell to the destination subscriber
PI) and VCI to 0 (S1 in FIG. 6)
4). After this, S16 is executed and the cell reception buffer unit 4
The upstream cell to the LAN to be activated stored in No. 2 is read and transmitted to the LAN to be activated via the ATM exchange.

On the other hand, the inter-LAN connecting device accommodating the LAN of the activation destination is the LAN of the activation source from the LAN subscriber of the activation destination.
Allocate receive buffers (not shown in FIG. 6) to receive cells using VPI / VCI for downlink to subscribers.

In step S15 of FIG. 6, information in the reverse direction (downlink) from the LAN at the activation destination to the LAN at the activation source is set as the LA at the activation destination.
It is received by the inter-LAN connecting device accommodating N, and is executed when it is determined in step 9 that the VCI is not the address of the inter-LAN connecting device through the processing of S5 to S8 in FIGS. In this case, VCI = 0 between the LAN and the LAN-to-LAN connecting device is set by PVC, and the destination address of the downlink LAN data sets the output VPI and the output VCI for the VC path stored in the header conversion table.

By setting this header conversion table, the cell header of the LAN data in the reverse direction (downlink) from the LAN subscriber to be activated is converted into VPI / VCI for the VC path and passed to the ATM switch. The subsequent transfer information between LAN-to-LAN connecting devices is that the PVC handles the upstream signal and the VC handles the downstream signal.

In S0 of FIG. 5, when the path connection request by the above VC (S10 of FIG. 6) arrives at the partner LAN inter-connection device, the LAN inter-connection device receives the reception VP.
An empty cell reception buffer used by a cell having I / VCI is allocated (S3 in FIG. 5), and a supervisory control unit (45 in FIG. 4)
Request to monitor the corresponding cell reception buffer (S in FIG. 5).
4).

In the state of S0 in FIG. 5, when a path disconnection request for the VC is issued from the ATM switch, the VP for the corresponding VC is read from the address translation table (47 in FIG. 4).
The I / VCI information is deleted (S20 in FIG. 5).

Further, in S0 of FIG. 5, when a path disconnection request is issued from the supervisory control unit (45 in FIG. 4) in the inter-LAN connecting device accommodating the LAN which requests the LAN service, the VC path is sent to the ATM switch. A disconnection request is made (S1 in FIG. 5) and the corresponding VC is read by the address conversion table.
Information for use is deleted (S2 in FIG. 5).

The configuration and control operation of the monitoring control unit (45 in FIG. 4) that issues the disconnection request in S1 will be described. The supervisory controller is the LA that first receives the LAN service from the subscriber.
In the N-to-N connecting device, the traffic flowing using the VC path is monitored, and when the absence of traffic for a certain period of time is detected, a request for disconnecting the path established by the LAN connecting device accommodating the other subscriber is made. Release the path in the ATM switch. Upon receiving the release, the partner LAN-to-LAN connecting device deletes the added information in the corresponding address conversion table.

FIG. 8 shows a related block diagram of the monitoring control unit, and FIG. 9 shows a processing flow of the monitoring control. In FIG. 8, 42 is a cell reception buffer unit, 45 is a monitoring control unit, 450 is a cell reception state management table, and 451 is a timing monitoring program.

In such a configuration, the monitor control unit 45
A. of FIG. Control is performed as shown in. When the cell using the corresponding buffer unit is received by the cell reception buffer unit 42 which receives the VC cell, "1" is set in the flag area (FLAG) of the corresponding position of the cell reception state management table 450 ( 9 (S1). Next, it is judged whether the "ACT" bit representing the state of the table 450 is "1" (at step S2),
If it is not "1", "1" is set (S3 of the same), information (value used in VC) is set to the VPI / VCI of the corresponding position (S4 of the same), and the "timing monitoring program that operates at a constant cycle" Is started (at step S5). Then, the flag bit of the table 450 is set to "1". (S6 of the same) The timing monitoring program is shown in FIG. As shown in FIG. 4, when the cycle is activated in S5, the flag bit in which the ACT bit is set (the state of "1") is obtained (in the same S
7) If the flag bit is "0", since no cell has been received for a certain period of time, a disconnection request for a path using the corresponding VPI / VCI is issued (S9), and the process ends. If the flag bit is not "0" (at step S8), A
The flag at the corresponding position where the CT bit is set is set to "0" (at step S10), and the process ends.

[0054]

According to the present invention, it is possible to assume a large traffic amount in advance, set the amount of the band for which the PVC is set to half, and manage the downlink traffic in the actually used band. ， The resources in the network can be used effectively. As a result, this amount can be assigned to other traffic. Further, since the VC path is established before the downlink information flows, the LAN-to-LAN connection service can be provided at a high speed, similar to the normal PVC-to-LAN connection.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a system configuration diagram in which the present invention is implemented.

FIG. 3 is a configuration diagram of LAN data and cells.

FIG. 4 is a configuration diagram of an embodiment of a LAN-to-LAN connecting device.

FIG. 5 is a control flow (No. 1) in the LAN-to-LAN connecting device.

FIG. 6 is a control flow (No. 2) in the LAN-to-LAN connecting device.

FIG. 7 is a configuration diagram of each table.

FIG. 8 is a related configuration diagram of a monitor control unit.

FIG. 9 shows a processing flow of monitoring control.

FIG. 10 is an explanatory diagram of a conventional example.

[Explanation of symbols]

1 Start-up LAN 2 Broadband network 3 Inter-LAN connection device accommodating start-up LAN 4 Inter-LAN connection device adjacent to inter-LAN connection device 3 Inter-LAN connection device 6 including start-up LAN 6 Start-up LAN

Claims (2)

[Claims] 1. A semi-fixed connection means (PVC) in which a plurality of LAN-to-LAN connecting devices connected to a broadband switching network are preset by a broadband switching device for connection with subscribers and other LAN-to-LAN connecting devices. In the system provided, the connection between the LAN inter-connection device accommodating the initiating subscriber and the LAN inter-connection device accommodating the activation destination subscriber through the broadband switching network is semi-fixed when the traffic over the LAN inter-connection device occurs. The inter-LAN connecting device that allocates the path of the connecting means and accommodates the initiating subscriber is connected to the broadband switching network by a call-by-call connection path to the inter-LAN connecting device that accommodates the initiating subscriber. LAN which is formed by VC and accommodates the activation destination subscriber by the set path.
An inter-LAN connection control method for transmitting downlink traffic flowing from an inter-connection device to an initiating LAN-to-LAN connection device. 2. The inter-LAN connection device accommodating the activation-source subscriber according to claim 1, comprising means for monitoring a traffic volume for a certain period of time, and when it is judged that there is no traffic, the activation-destination LAN connection device is activated. A LAN characterized by requesting a broadband switching network to release a path (VC) set to an original inter-LAN connecting device
Inter-connection control method.