JPH06343073A - Inter-network connecting device - Google Patents

Abstract

PURPOSE:To set the optimum reference time in response to the communications distance and to attain the economical use of a public communications circuit by connecting this circuit to a local area network and identifying the network of the receiver side based on the data received from the local area network. CONSTITUTION:The inter-network connecting devices 3 are placed between a public circuit 1 and plural LAN 2, and the LAN 2 of the receiver side are identified based on the data received from those LAN 2. Then a communications channel is fixed. When either one of LAN 2 reaches the reference time after the communications channel is fixed, the communications channel set among plural LAN 2 via the circuit 1 is cut off. The reference time setting information corresponding to the LAN 2 of the receiver side are stored in a memory which is not shown in the diagram, and the reference time is set at each time and for each receiver side. In such a constitutuin, the most economical circuit 1 is available for each receiver side by means of the devices 3 in regard of the use of the circuit 1 where the call rate is set by the communications distance and the communications time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inter-network connection device for relaying communication between two local area networks connected via a public communication line, and particularly to transmitting / receiving communication data between the two local area networks. The present invention relates to an inter-network connection device having a function of automatically disconnecting a public communication line when a state in which the communication is not performed continues for a predetermined time or longer.

[0002]

2. Description of the Related Art In recent years, an Internet environment for connecting a plurality of networks to each other has been established. As shown in FIG. 3, for example, public telephone lines, high-speed digital lines, packet switching networks, integrated service digital networks (ISDN:
A plurality of local area networks (LA) are connected to the public communication line 51 such as Integrated Services Digital Network).
N: Local Area Network) 52 ... Is connected to enable smooth data communication between LANs that are distant from each other.

An inter-network connection device 53 is used to connect each of the LANs 52 and the public communication line 51. The inter-network connecting device 53 enables communication between both networks by performing mutual conversion of the protocols of the different types of networks (LAN 52, public communication line 51).

In the above network communication system, each LAN 52 connected to the public communication line 51 is provided with an identifier called a network number (network address) for uniquely identifying each LAN 52 in the Internet environment. . In addition, each LAN 52
Each terminal device 54 connected to is provided with an identifier called a local number (local address) or a host number for uniquely identifying it on the LAN 52.

When communication is performed in the above network communication system, the inter-network connection device 53a
Is the terminal device 54 of the LAN 52a connected to it.
When the transmission data is received from a, the network number of the LAN 52b to which the connection destination is connected is determined from the local number of the connection destination included in the data, and the LAN 52b of the transmission destination is identified. Then, the inter-network connecting device 53a establishes a communication path with the inter-network connecting device 53b to which the destination LAN 52b is connected via the public communication line 51, and then transmits the transmission data.
The data is transferred to the destination inter-network connecting device 53b via the public communication line 51. The inter-network connecting device 53b identifies the target terminal device 54b from the local number included in the data received from the public communication line 51, and sends the received data to the terminal device 54b.

[0006] Here, when using a public communication line having a charge system that is charged according to a communication distance and a line use time, such as a public telephone line and an ISDN line, public communication is performed only when data is transmitted and received. Using the line is the most economical. Therefore, the conventional inter-network connection device has a function of automatically disconnecting the public communication line when data is not transmitted / received for a certain period of time while using the public communication line. There is something.

In the conventional inter-network connecting device, the non-communication time for determining that there is no transmission / reception data is always set to a fixed time regardless of the communication distance. Normally, the line for long-distance communication is used. In order to reduce the usage fee,
The determination time is set to a relatively short time.

[0008]

However, when the non-communication time for determining that there is no transmission / reception data is set to a relatively short time as in the above-described conventional configuration, the line is frequently connected / disconnected. And the following inconveniences occur.

That is, if the line is frequently connected / disconnected, it takes time to connect / disconnect the line, resulting in a large transmission delay. In the case of communication within the same area, the communication charge within a relatively long basic time (for example, 3 minutes) is constant, and even if the line is connected / disconnected at short time intervals, the communication charge will be low. Not limited to this, if the line is connected / disconnected multiple times within the basic time, the communication fee will be increased.

Further, even in the case of long-distance communication, the non-communication time for judging that there is no transmission / reception data is always irrespective of the communication distance even though the communication charge is set according to the communication distance. If it is set to a fixed value, it may not always be economical depending on the connection destination.

The present invention has been made in view of the above, and an object thereof is to provide an inter-network connection device which can use the most economical public communication line according to the destination.

[0012]

The inter-network connection device of the present invention is provided between a local area network and a public communication line (for example, ISDN line) and is based on data received from the connected local area network. , The destination local area network is identified, and the communication path through the public communication line between both local area networks is established, while the non-communication duration between both local area networks after the establishment of the communication path is When the reference time is reached, the communication path between both local area networks via the public communication line is disconnected, and the following means are taken to solve the above problems. I am trying.

That is, the inter-network connecting device sets the reference time based on the storage means for storing the reference time setting information corresponding to the destination local area network in advance and the reference time setting information. And a reference time setting means.

[0014]

According to the above structure, the inter-network connecting device identifies the destination local area network based on the data received from the local area network, and connects via the public communication line between the two local area networks. The communication path is established, and each time the communication path is established, the reference time setting means sets the reference time based on the reference time setting information stored in the storage means in advance. It will be.

Therefore, if the reference time setting information according to the distance of the destination local area network is stored (registered) in the storage means in advance, the reference time setting according to the communication distance is set for each destination. Is possible. Therefore, when using a public communication line such as an ISDN line whose communication charge is set according to the communication distance and the communication time, it becomes possible to set the optimum reference time according to the communication distance, and it is possible to set it according to the destination. The most economical public communication line can be used.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will describe one embodiment of the present invention with reference to FIGS. 1 and 2.

Inter-network connection device 3 according to the present embodiment
As shown in FIG. 1, a service integrated digital network (hereinafter referred to as ISDN line) 1 as a public communication line and a local area network (hereinafter referred to as LAN)
It is provided between the two and relays the communication between the two.

The inter-network connection device 3 is a so-called I interface (International Telegraph and Telephone Advisory Committee (CC
I.T.). 430-based ISDN basic interface, or CCITT I.D. It is connected to the ISDN line 1 via the ISDN primary group speed interface 5 based on 431, and is also connected to the LAN 2 via the LAN interface 6.

As shown in FIG. 2, the inter-network connecting device 3 is a CPU (Centra) for controlling the operation of the entire device.
I Processing Unit) 7, a program executed by the CPU 7, control data, and a memory 8 used for temporary storage of communication target data and parameter storage, and I
An I interface control unit 9 for controlling communication with the ISDN line 1 via the interface 5 and a LAN interface control unit 10 for controlling communication with the LAN 2 via the LAN interface 6 are provided. 7 to 10 are connected to each other via an internal bus 11.

In the memory 8 as a storage means, a local number of each terminal device 4, an ISDN number as a network number corresponding to this local number, and this IS
A table in which reference time setting information corresponding to the DN number is registered is stored.

In this embodiment, as the reference time setting information, three pieces of information, "reference time data for short distance communication", "reference time data for medium distance communication" and "reference time data for long distance communication" are prepared. Has been done. The “reference time data for short-distance communication” is the reference time setting to be registered when the destination LAN 2 (inter-network connecting device 3 connected to the destination LAN 2) exists in the same area on the communication charge system. Information. The "reference time data for medium-distance communication" and the "reference time data for long-distance communication" are transmitted to the LAN2 of the transmission destination.
Is outside the same area in the communication charge system, and is the reference time setting information to be registered when it is separated from the transmission destination LAN 2 by a medium distance and a long distance.

Then, in the memory 8, from the local number included in the transmission data received from the LAN 2 connected to the inter-network connecting device 3, the ISDN number of the transmission destination corresponding to this local number is acquired from the above table. Then, a program for establishing a communication path between the LAN 2 and the LAN 2 corresponding to the acquired ISDN number via the ISDN line 1 is stored.

Further, the memory 8 is provided with a message for disconnecting the ISDN line 1 based on the reference time setting information corresponding to the destination of the data received from the LAN 2 connected to the inter-network connecting device 3. A program for setting a reference time serving as a determination reference is stored. The CPU 7 that executes this program constitutes a reference time setting means.

The memory 8 stores the ISD between the LANs 2 and 2 when the non-communication duration between the two LANs 2 and 2 after the establishment of the communication path reaches the reference time.
A program for disconnecting the communication path via the N line 1 is stored.

The operation of the inter-network connecting device 3 having the above configuration will be described below. For convenience of explanation, in FIG. 1, each LAN2 ... Is attached with an identification code of 2a to 2d, and the inter-network connection device 3 to which the LANs 2a and 2b are connected is provided with 3a and 3b and LAN2, respectively.
The identification codes 4a to 4d are added to the terminal devices 4 on a to 2d, respectively. In addition, LAN2a and LAN2b exist in the same area in the charge system, and LAN2c and LAN2c
2d exists in a separate area from the charge system of the LAN 2a, and the distance from the LAN 2a is LAN 2d.
It is farther than 2c. That is, LAN2a is LA
N2b performs short-distance (within area) communication, LAN2c performs medium-distance communication, and LAN2d performs long-distance communication.

For example, when transmitting information data from the terminal device 4a on the LAN 2a to the terminal device 4b on the LAN 2b, first, the terminal device 4a on the LAN 2a is connected to the LAN 2a.
The transmission data is sent to the inter-network connecting device 3a via.

The inter-network connecting device 3a is an LA
When the transmission data is received from N2a, the ISDN number corresponding to the local number of the transmission destination included in the data is acquired from the table in the memory 8 to identify the LAN3b of the transmission destination. Then, the inter-network connecting device 3a creates a call setup message according to the ISDN number, and sends this to the ISDN line 1
Send to.

The inter-network connecting device 3b to which the LAN 3b is connected receives the call setting message relayed by the ISDN line 1. When the inter-network connecting device 3b accepts the call setting message, it creates a call setting accepting message and sends it to the ISDN line 1.

The inter-network connection device 3a is an ISDN.
The call setup acceptance message relayed by the line 1 is received, whereby the ISDN line 1 between the LANs 2a and 2b is received.
A communication path is established through the (ISDN line 1 is connected).

When the ISDN line 1 is connected, the inter-network connecting device 3a acquires the reference time setting information corresponding to the connection destination from the table in the memory 8 and, based on the reference time setting information, A reference time is set as a reference when the ISDN line 1 is disconnected.

In the above case, the transmission destination is the LAN 2b existing in the same area on the charge system, and the "reference distance data for short-distance communication" is registered in the table in the memory 8 in advance. The inter-connector 3a sets the above reference time as the longest short-distance communication reference time.

After this, the inter-network connecting device 3a
Transmission data from the LAN 2a is transmitted to the inter-network connecting device 3b via the ISDN line 1. Upon receiving the data from the inter-network connecting device 3a, the inter-network connecting device 3b transmits the data to the terminal device 4b via the LAN 2b.

The inter-network connection device 3a is also provided.
If a state (non-communication state) in which data is not transmitted / received between the LANs 2a and 2b occurs after the ISDN line 1 is connected, the counter measures the duration of the non-communication state. Then, when the non-communication duration between the LANs 2a and 2b reaches the reference time set above, I
The communication path via the SDN line 1 is disconnected.

That is, the inter-network connecting device 3a
Issues a line disconnection request message to the ISDN line 1 when the non-communication duration between the LANs 2a and 2b reaches the reference time. Then, when the ISDN line 1 notifies the inter-network connecting device 3b as a line disconnection instruction, the inter-network connecting device 3b responds to this. Based on this response, the ISDN line 1 disconnects the communication line set between the inter-network connecting devices 3a and 3b. The inter-network connecting device 3a notifies the terminal device 4a that this communication line has been disconnected.

After this, the inter-network connecting device 3a
When the transmission data is received again from the LAN 2a, the ISDN line 1 is connected in the same manner as above.

On the other hand, the inter-network connecting device 3a
LAN2 at a medium distance from the terminal device 4a on the AN2a
When the data to be transmitted to the terminal device 4c on c is received, the "intermediate distance communication reference time data" is acquired from the table in the memory 8 as the reference time setting information. Therefore, in this case, the inter-network connecting device 3a sets the reference time according to the "intermediate-distance communication reference time data" after connecting the ISDN line 1 in the same manner as described above.

Further, the inter-network connecting device 3a is
LAN2 located at a long distance from the terminal device 4a on the AN2a
When the data to be transmitted to the terminal device 4d on d is received, the "reference distance data for long distance communication" is acquired from the table in the memory 8 as the reference time setting information. Therefore, in this case, the inter-network connecting device 3a sets the above-mentioned reference time to the shortest predetermined time according to the "long-distance communication reference time data" after connecting the ISDN line 1 in the same manner as above. To do.

As described above, the inter-network connecting device 3 of this embodiment is provided between the LAN 2 and the ISDN line 1 and identifies the destination LAN 2 based on the data received from the connected LAN 2. Then, while establishing a communication path between the LANs 2 and 2 through the public communication line,
When the non-communication duration between both LANs 2 and 2 after the establishment of the communication path reaches the reference time, the communication path is disconnected via the ISDN line 1 between both LANs 2 and 2, and the destination The memory 8 has a table for registering reference time setting information corresponding to the LAN 2 and is configured to set the reference time for each destination based on the reference time setting information. .

As a result, when the ISDN line 1 whose communication charge is set according to the communication distance and the communication time is used, by using the inter-network connecting device 3, the most economical according to the destination. The ISDN line 1 can be used.

That is, in the past, the reference time, which is the criterion for the disconnection of the ISDN line by the inter-network connecting device, is always constant regardless of the connection destination, and the communication distance is not considered at all. On the other hand, in this embodiment, by registering the reference time setting information according to the communication distance for each destination, it becomes possible to set the reference time according to the communication distance for each destination, which is economical. Use of the ISDN line 1 can be realized.

For example, in short-distance communication such as communication within the same area, since the reference time is set to be relatively long, connection / disconnection of the ISDN line 1 is unlikely to occur continuously in a short period of time, and it is less than conventional. The transmission delay is small and the communication charge is low.

In this embodiment, the public communication line I
Although the SDN line 1 has been described as an example, the present invention is not limited to this. For example, if the public communication line has a charge system that is charged according to the communication distance and the line usage time, such as a public telephone line, The network connection device 3 can be applied.

Further, in this embodiment, the reference time in the inter-network connecting device 3 can be set in three steps, but it may be set in more steps.
Further, stepless setting is also possible in which the reference time to be set is designated by a numerical value.

The above-mentioned embodiments are intended to clarify the technical contents of the present invention, and should not be construed in a narrow sense by limiting to such specific examples. Various modifications can be made within the scope of the claims.

[0045]

As described above, the inter-network connecting device of the present invention is provided between the local area network and the public communication line, and the transmission destination is based on the data received from the connected local area network. Of the local area network and establish a communication path via the public communication line between both local area networks, while the non-communication duration between both local area networks after the communication path is established reaches the reference time. Storage means for disconnecting the communication path between the two local area networks via the public communication line, and storing in advance reference time setting information corresponding to the destination local area network. A reference time setting means for setting the reference time based on the reference time setting information. It is configured to have.

Therefore, if the reference time setting information according to the distance of the destination local area network is stored in the storage means in advance, the reference time according to the communication distance can be set for each destination. Yes, when using public communication lines such as ISDN lines whose communication charges are set according to communication distance and communication time, it is possible to set the optimum reference time according to communication distance, and depending on the destination, The effect is that the most economical public communication line can be used.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a network communication system using an inter-network connecting device of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of the inter-network connection device.

FIG. 3 is a block diagram showing a schematic configuration of a network communication system using a conventional inter-network connecting device.

[Explanation of symbols]

 1 integrated service digital network (public communication line) 2 local area network 3 inter-network connection device 4 terminal device 5 I interface 6 LAN interface 7 CPU (reference time setting means) 8 memory (storage means) 9 I interface control unit 10 LAN interface Control unit

Claims (1)

[Claims] 1. A local area network of a destination is identified based on data received from a local area network connected between the local area network and a public communication line, and the local area network between the two local area networks is identified. While establishing a communication path via the public communication line, when the non-communication duration between both local area networks after the communication path is established reaches a reference time, the public communication line between both local area networks An inter-network connecting device for disconnecting a communication path via a storage means, which stores in advance reference time setting information corresponding to a destination local area network; and, based on the reference time setting information, And a reference time setting means for setting the reference time. Inter-station connection device.