JPH05316115A - Computer network connector - Google Patents

Abstract

PURPOSE:To implement efficiently and accurately access control between plural terminals connected to a computer network by using a time access control table storing access control conditions comprising information of date, day of week, time and address information of the terminals. CONSTITUTION:The connector consists of a router function section 2 executing a routing, a time access control table 4 storing access control conditions comprising information of date, day, time and address information of a terminal, a date/day/time generator 5 generating a current date/day of week/time and a local interface 3(3a-3c) connecting a router 1 to a computer network. That is, the date/day/time generator 5 informs the current date/day/time to the router function section 2, and when the router function section 2 receives a frame from a computer network, the router function section 2 retrieves the time access control table 4 and compares access control conditions to decide whether or not the frame is to be relayed to the destination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer network connection device, and in particular, a plurality of computer networks for connecting a plurality of terminals are mutually connected to perform access control by date, day of the week, time or group number and load distribution of a dedicated line. The present invention relates to a computer network connection device that can be efficiently performed.

[0002]

2. Description of the Related Art A computer network is a system in which a plurality of information processing terminals such as computers are connected by optical fibers or electric cables, data is transmitted and received between the terminals, and an output device or a storage device used by each terminal. It realizes functions such as sharing. Such computer networks can be connected to each other using a so-called computer network connection device such as a bridge device or a router device. In a computer network system connected to each other by a computer network connection device, a plurality of terminals on different computer networks can communicate with each other.

When one terminal transmits data to another terminal, the source terminal adds the terminal address of the source and the terminal address of the destination to the transmission data and transmits the data. Such a transmission data with the source and destination terminal addresses added is called a frame. Further, in this case, the address is an identifier for uniquely identifying the terminal in the mutually connected computer network systems.

A conventional computer network connection device such as a bridge device or a router device is outlined on pages 30 to 35 of Ohmsha Co., Ltd., "Heterogeneous Connection and LAN Picture Book." That is,
The bridge device connects two or more computer networks to each other, and makes the system appear as if forming one computer network. The bridge device having such a function relays a frame received from one computer network to another computer network.

On the other hand, the router device has a function similar to that of the bridge device in that two or more computer networks are connected to each other and a frame is relayed to another computer network. The difference is that the optimal route is selected and used when there are multiple routes between terminals. Such a router device internally has a table called a routing table that stores an optimum route. Upon receiving the frame, the router device searches the routing table based on the destination address, determines the destination to which the frame should be relayed (routing destination), and relays the frame. When the router device receives the frame and relays the frame so as to follow the optimum route, it is called routing.

Some router devices can be connected to other router devices at remote locations by a dedicated line. When the router device receives the frame and routes it, and determines that the routing destination is a computer network to which the router device at the remote place is connected, the frame is transmitted to the router device at the remote place using a dedicated line. The router device is connected to the dedicated line by the remote interface. Use a method of connecting such a set of router devices with two dedicated lines each, normally using only one of them, and leaving the other dedicated lines for backup. Is also possible. in this case,
If the normally used private line fails and becomes unusable, it is possible to continue communication by switching to and using the backup private line. Further, either one of the leased lines may be arbitrarily used without using the method of making one of the leased lines stand by for backup.

It should be noted that being able to access between arbitrary terminals means that the source terminal can transmit data to the destination terminal and the destination terminal can receive this data. The access control is to provide a condition for determining whether or not the router device relays the received frame. For this condition, for example, various kinds of information stored in the frame such as a source address, a destination address of the frame, or a combination of the source address and the destination address are used. Usually, access control between terminals is used on condition of a source address, a destination address, or both.

FIG. 20 is a block diagram showing the internal structure of a conventional router device. In the figure, a conventional router device 109 includes a router function unit 110 that executes routing.
, An access control table unit 111, and a remote interface unit 33 for connecting the router device to a dedicated line.
And local interface units 3a, 3b, 3c for connecting the router device to the computer network.

FIG. 21 is a block diagram of a computer network system using the conventional router device 109 shown in FIG. In the figure, a conventional computer network system includes router devices 109a and 10a.
9b, the computer networks 6a, 6b, 6c connected to the router device 109a, and the router device 109b.
To the computer network 6d, terminals 7a to 7f connected to the computer networks 6a, 6b and 6c, terminals 7g and 7h connected to the computer network 6d, and router devices 109a and 109b.
Are connected to each other by dedicated lines 36a and 36b.

Further, FIG. 22 is a flowchart showing the operation contents of the router function unit 110 of the conventional router device 109 shown in FIG.

The access control table section 11 shown in FIG.
Each entry constituting 1 indicates a condition for access control. In the conventional router device, for example, the source control address and the destination address of the frame are included in the access control conditions. In the following description, the source control address and the destination address of the frame are also specified.

In this case, the access control table section 111
The access control is performed such that access from the source address stored in each entry to the destination address is prohibited, and access other than that is permitted. It should be noted that as many entries as the number of conditions for prohibiting access are registered in the access control table section 111.

In the conventional router device, when the source address and the destination address are not specified in the access control table section 111, that is, when the access control condition is not set, the terminals 7a and 7 shown in FIG.
b, 7c, 7d, 7e, and 7f can access each other.

Now, for example, regarding the terminal 7a, the terminal 7
b, 7c, 7e, and 7f can access each other, but the terminal 7d cannot access each other. To this end, the access control table section 111 is set as shown in FIG. In each entry of the access control table 111, the left side of the arrow shown in the figure is the source address, and the right side of the arrow is the destination address. Access control of a condition that matches any entry of the access control table 111 is prohibited, and other access control is permitted.

When Communication is Allowed A case where the terminal 7a transmits a frame to the terminal 7c will be described with reference to the flowchart of FIG. First,
In FIG. 21, the terminal 7a sets the address of its own station as the source address and the address of the terminal 7c as the destination address, and transmits the frame 8. The local interface unit 3a of the router device 109a uses the frame 8
(Step 112), the router function unit 110 is received.
Determines the routing destination from the data of frame 8 (step 113).

Next, the router function unit 110 searches the access control table unit 111, and as shown in FIG. 23, the access control table unit 111 has two entries. The router function unit 110 first extracts the first entry (step 114), and if the condition is registered (step 115), the source address and the destination address as conditions specified by the entry and the received frame 8 are received. The source address and the destination address are compared (step 116). In this case, the destination address specified by the entry is the terminal 7d, but the destination address set in the frame 8 is the terminal 7c and the conditions do not match (step 117). Therefore, the router function unit 110 stores the access control table unit 111 in the access control table unit 111. Retrieve next entry (step 1
18). If the condition is registered in the entry (step 115), the same processing as in the case of the first entry is performed.

In this way, the access control table unit 1
The last entry 11 is checked, and if there is no entry that matches the conditions, the router function unit 110 determines that access is permitted, and transmits the frame 8 to the routing destination. In this case, since the destination terminal 7c is connected to the computer network 6b and the routing destination is the computer network and not the dedicated line (step 120), it is transmitted to the routing destination determined by the router function unit 110. (Step 124). Therefore, the frame is transmitted to the computer network 6b that is the routing destination, and the terminal 7c eventually receives the frame 8.

When Communication is Not Allowed A case where the terminal 7a transmits a frame to the terminal 7d will be described based on the flowchart of FIG. First,
In FIG. 21, the terminal 7a sets the address of its own station as the source address and the address of the terminal 7d as the destination address, and transmits the frame 8. The local interface unit 3a of the router device 109a uses the frame 8
(Step 112), the router function unit 110 is received.
Determines the routing destination from the data of frame 8 (step 113).

Next, the router function unit 110 searches the access control table unit 111. As shown in FIG. 23, the access control table unit 111 has two entries. The router function unit 110 first extracts the first entry (step 114), and if the condition is registered (step 115), the source address and the destination address as conditions specified by the entry and the received frame 8 are received. The source address and the destination address are compared (step 116). In this case, since the destination address specified by the entry is the terminal 7d and the destination address set in the frame 8 is also the terminal 7d, the conditions match (step 117), and the router function unit 110 is prohibited from accessing. Then, the frame 8 is discarded (step 119). Therefore, the terminal 7d does not receive the frame 8.

Next, the case of using a dedicated line will be described. Of the two dedicated lines 36a and 36b shown in FIG. 21, the dedicated line 36a is a normally used dedicated line, and the dedicated line 36b is a backup dedicated line. In the following description, no access control condition is set between any terminals. Therefore, no entry is set in the access control table section 111.

When using a normal leased line A case where the terminal 7a transmits a frame to the terminal 7h will be described based on the flowchart of FIG. First,
In FIG. 21, the terminal 7a sets its own address as the source address and the address of the terminal 7h as the destination address, and transmits the frame 8. The local interface unit 3a of the router device 109a uses the frame 8
(Step 112), the router function unit 110 is received.
Determines the routing destination from the data of frame 8 (step 113).

Next, the router function unit 110 searches the access control table unit 111, but there is no entry in the access control table unit 111. The router function unit 110 first tries to retrieve the first entry (step 1
14), because the entry is not registered (step 1
15), the router function unit 110 determines that the access is permitted, and transmits the frame 8 to the routing destination. In this case, since the routing destination is the leased line (step 120), it is confirmed whether the normally used leased line 36a is available (step 12).
1). Since the leased line 36a can be used, the router device 109a transmits the frame 8 to the leased line 36a (step 122). The router device 109b receives the frame 8 and performs routing, transmits it to the computer network 6d, and the terminal 7h receives the frame 8.

When a dedicated leased line for backup is used When a failure occurs in the leased line 36a, the router device 1
The router function unit 110 of 09a detects that a failure has occurred in the private line 36a, and thereafter manages the private line 36a as unusable. Then, for subsequent access to the dedicated line, the dedicated line 36b prepared for backup is used instead of the dedicated line 36a. Therefore, similar to the above case, a case where the terminal 7a transmits a frame to the terminal 7h will be described based on the flowchart of FIG.

A case where the terminal 7a transmits a frame to the terminal 7h will be described with reference to the flowchart of FIG. First, in FIG. 21, the terminal 7a sets the address of its own station as the source address and the address of the terminal 7h as the destination address, and transmits the frame 8.
When the local interface unit 3a of the router device 109a receives the frame 8 (step 112), the router function unit 110 determines the routing destination from the data of the frame 8 (step 113).

Next, the router function unit 110 searches the access control table unit 111, but there is no entry in the access control table unit 111. The router function unit 110 first tries to retrieve the first entry (step 1
14), because the entry is not registered (step 1
15), the router function unit 110 determines that the access is permitted, and transmits the frame 8 to the routing destination. In this case, since the routing destination is the leased line (step 120), it is confirmed whether the normally used leased line 36a is available (step 12).
1). Since the leased line 36a is currently managed to be unusable due to a failure, the router function unit 110 of the router device 109a transmits the frame 8 to the backup leased line 36b (step 123). Router device 10
9b receives this frame 8 and performs routing,
The terminal 7h receives the frame 8 by transmitting it to the computer network 6d.

When it is not specified in advance which of the dedicated lines to use In the access control described above, which of the two dedicated lines 36a and 36b is normally used is determined in advance. However, a method different from this may be used, for example, a case in which the leased line to be used is not determined.

For example, the router function unit 110 receives a frame, determines a routing destination, and when the routing destination is a dedicated line, sends the frame to a dedicated line different from the previously used dedicated line. There is a method. That is, if the previously transmitted line is the dedicated line 36b, the frame is transmitted to the dedicated line 36a this time.
If the previously transmitted line is the dedicated line 36a, the frame is transmitted to the dedicated line 36b this time.

[0028]

As described above, in the access control of the conventional router device, the source address, the destination address, or the combination information thereof is often used as the access control condition. There is a problem that it is not possible to cope with the tendency of labor saving (for example, performing access control by designating a predetermined date, day of the week, time, etc.). That is, under the conventional access control condition, access control is performed only by the source address and the destination address regardless of the date, the day of the week, and the time. For example, the access control is performed only from 5 pm on Friday to 9 am on Monday. Could not be specified.

Further, a plurality of terminals are divided into respective groups, the group numbers are managed, and at the time of access, the group number is designated to realize the access control between the groups, thereby controlling the access between the terminals. However, there is a problem in that there is no automation / labor saving means such as saving the labor required to specify the terminal address.

Further, even if there are two dedicated lines as a system, such as "when using a normal dedicated line" or "when using a backup dedicated line" described in the above-mentioned prior art, it is usually used. Only one line was used and the other leased lines were not used unless the used line failed. Therefore, although the backup dedicated line is prepared, there is a problem that the traffic of the normally used dedicated line increases and all the communication cannot be processed.

Further, in the case where "which one of the leased lines is to be used is not specified in advance" explained in the above-mentioned prior art, 2
When deciding which of the dedicated lines to use, the decision was made without considering which of the dedicated lines has a light load, so the problem is that load distribution cannot be performed effectively. was there.

Further, in determining which of the two dedicated lines has the lighter load, the method of selecting the dedicated line with the smaller delay does not consider the delay inherent in the dedicated line. There was a problem that a dedicated line with a light load could not be selected correctly.

The present invention has been made in order to solve the above-mentioned problems, and connects a plurality of computer networks for connecting a plurality of terminals to each other to access control by date, day of the week, time or group number, The purpose is to obtain a computer network connection device capable of efficiently and accurately distributing the load of a dedicated line.

[0034]

In order to achieve the above object, a computer network connection apparatus according to a first invention of the present invention is a computer network connection apparatus for connecting a plurality of computer networks for connecting a plurality of terminals to each other. In, the date / day / time generation means for generating the current date / day / day / time, and time access control for performing access control between terminals based on date / day / time or combination information thereof and terminal address information, etc. Table and output information from date / day / time generation means,
And a control means for controlling access between different computer network terminals based on the terminal address of the frame received from the computer network and the contents of the time access control table.

Further, the computer network connection apparatus according to the second aspect of the present invention divides a plurality of terminal addresses into groups and registers the correspondence between terminals and group numbers, and the current date, day of the week, and time. The date / day of the week / time generation means that occurs, the time / day of the week / time, or a time access control table for controlling access between groups by the combination information and group number information, and the date / day of the week / time generation means Control means for controlling access between different computer network terminals based on the output information, the terminal address of the received frame from the computer network, and the contents of the time access control table.

The computer network connection apparatus according to the third aspect of the present invention comprises a dedicated line connection means for interconnecting another computer network connection apparatus constituting the computer network system with two dedicated lines, and a dedicated line connection means. Traffic measurement means for measuring traffic, date / day / time generation means for generating the current date / day of the week / time, date / day / hour / time or combination of these information, and determination of start of use of a dedicated leased line for backup Traffic threshold table for storing a high traffic threshold for determining the suspension of a dedicated line for backup and a low traffic threshold for determining whether to stop using the dedicated leased line for backup,
Normally, one dedicated line is used, and when the output information of the traffic measuring means exceeds the high traffic threshold value in the traffic threshold table, the backup dedicated line is started to be used and the output information of the traffic measuring means is It is characterized by comprising control means for stopping the use of the backup dedicated line when the traffic value becomes lower than the low traffic threshold value of the traffic threshold value table.

The computer network connection apparatus according to the fourth aspect of the present invention includes a dedicated line connection means for interconnecting another computer network connection apparatus constituting the computer network system with two dedicated lines, and a current date.・ Date / day of the week / time generating means, day of the week / time generating means, test frame transmitting means for periodically transmitting the test frame storing the current time to the dedicated line, and receiving the test frame and storing it in the test frame The test frame inspection means for calculating the time difference between the time information and the current time is compared with the time difference which is the output information of the two test frame inspection means corresponding to the two dedicated lines,
A dedicated leased line storage means for storing a leased line with a small time difference as a currently used leased line, and a control means for selecting a leased line with a small delay of the two leased lines as the currently used leased line. ..

Further, the computer network connection apparatus according to the fifth aspect of the present invention includes a dedicated line connecting means for interconnecting another computer network connection apparatus constituting the computer network system with two dedicated lines, and a current date.・ Date / day / time generating means for generating the day of the week / time, traffic measuring means for measuring the traffic of the dedicated line, and test frame transmitting means for periodically transmitting a test frame storing the current time to the dedicated line, A test frame checking means for receiving a test frame and calculating the time difference between the time information stored in the test frame and the current time; and a test frame checking means calculated based on the test frame received when there is no other traffic. Reference time to store the time difference that is output information as the reference time difference A difference storage means, a dedicated use line storage means for comparing a time difference which is output information of the test frame inspection means and a time difference which is output information of the reference time difference storage means, and stores a leased line having a small time difference as a currently used leased line. The present invention is characterized by comprising control means for selecting a dedicated line with a small delay from the two dedicated lines as a currently used dedicated line.

[0039]

Therefore, according to the computer network connection apparatus of the first aspect of the present invention, the date / day / day / time generation means generates the current date / day / day / time and notifies the router function section. When the functional unit receives a frame from the computer network, the functional unit can search the time access control table and perform access control between terminals based on date / day / time or combination information thereof and address information of terminals. That is, the current date, day of the week, time and terminal address stored in the frame is compared with the designated date, day of the week, time and terminal address of the time access control table to determine whether to relay the frame to the destination terminal. be able to.

Further, according to the computer network connection apparatus of the second aspect of the present invention, a plurality of terminal addresses are divided into respective groups and the correspondence between the terminals and the group numbers is registered in the group registration table, and the router function section is connected to the computer network. When a frame is received from a group, the group number specified in the time access control table is searched, and access between groups is controlled by the date / day / time or combination information and group number information. Access control conditions can be determined and specified in units.

According to the computer network connection apparatus of the third aspect of the present invention, the traffic of the leased line normally used by the traffic measuring means is measured and the backup value stored in the traffic value and the traffic threshold table is used. One of the leased lines is normally used by comparing it with the high traffic threshold for judging the start of the leased line of the other and the low traffic threshold for judging the suspension of the leased line for backup. However, when the output information of the traffic measuring means exceeds the high traffic threshold in the traffic threshold table, the dedicated leased line for backup is started, and the output information of the traffic measuring means shows the low traffic of the traffic threshold table. Stop using the leased line for backup when it goes below the threshold It is possible to achieve load distribution of leased lines with a.

Further, according to the computer network connection apparatus of the fourth aspect of the present invention, the test frame transmission means periodically transmits the test frame storing the current time to the dedicated line, and at the same time, it is transmitted from the partner computer network connection apparatus. The test frame inspection means calculates the time difference between the time information stored in the test frame and the current time. Then, the time difference which is the output information of the two test frame inspection means corresponding to the two leased lines is compared, and the leased line with a small time difference is selected and used as the currently used leased line to balance the load of the leased line. be able to.

Further, according to the computer network connection apparatus of the fifth invention, the time difference which is the output information of the test frame inspection means calculated based on the test frame received when there is no other traffic is stored as the reference time difference. In addition, when a frame is received from the computer network, the time difference from the test frame inspection means is compared with the reference time difference, and the dedicated line with a small time difference is selected and used as the currently used dedicated line to distribute the load on the dedicated line. Can be planned.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

Embodiment 1 FIG. 1 is a block diagram of a router device which is an embodiment of a computer network connection device according to the present invention. Incidentally, the same or corresponding parts as those of the conventional router device are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 1, the router device 1 of the present embodiment.
Is a router function unit 2 that executes routing, and
Time access control table unit 4 for storing access control conditions including day / time or combination information thereof and address information of the terminal, and date / date / day / time generating means for generating current date / day / time.・ Day / time generator 5 and local interface units 3a, 3 for connecting the router device to the computer network
b and 3c.

FIG. 2 is a block diagram of a computer network system using the router device 1 of this embodiment shown in FIG. In the figure, a computer network system according to the present embodiment includes a router device 1 and computer networks 6a, 6 connected to the router device 1.
b, 6c, terminals 7a, 7b connected to the computer network 6a, terminals 7c, 7d connected to the computer network 6b, and terminals 7e, 7f connected to the computer network 6c.

Further, FIG. 3 is a flowchart showing the operation contents of the router function unit 2 of this embodiment shown in FIG.

In the computer network system of this embodiment, access control between the terminals 7a and 7f is performed as follows. First, regardless of the date, between Monday and Friday, the terminals 7a and 7f can access each other from 9 am to 5 pm. However, from 5 pm to 9 am the next day, the terminals 7a and 7f cannot access each other. That is, the terminal 7a
Access to the terminal 7f is prohibited, and access from the terminal 7f to the terminal 7a is prohibited. In addition, regardless of the date, the terminals 7a and 7f cannot access each other at all times on Saturday and Sunday. However, the terminal 7a and the terminal 7f
For access other than during the period, mutual access is always permitted regardless of date, day of the week, and time.

FIG. 4 shows the contents of the time access control table 4 which stores the control conditions when the above access control is performed. In the figure, time access control table 4
Each of the entries that make up is a condition for time access control. In the router device 1 of this embodiment, since access control is performed regardless of the date, the source control address, the destination address, the day of the week, and the time of the frame are specified as the access control conditions. The item in the first column of each entry of the time access control table 4 is the condition specification of the day of the week and the time, and specifies the day of the week and the time zone in which access is prohibited. The item in the second column of each entry of the time access control table 4 is the condition specification of the source address and the destination address of the frame for which access is prohibited. The left side of the arrow in the figure is the source address and the right side of the arrow is It is the destination address. Access of a condition that matches any entry of the time access control table 4 is prohibited, and other access is permitted. Therefore, as many entries as the number of conditions for prohibiting access are registered in the time access control table 4.

When Access is Permissioned The case where the terminal 7a transmits a frame to the terminal 7f at 11:00 AM on Wednesday will be described based on the flowchart of FIG. First, the terminal 7a transmits the frame 8 by setting its own address as the source address and the terminal address of the terminal 7f as the destination address. When the local interface unit 3a of the router device 1 receives the frame 8 (step 9), the router function unit 2 determines the routing destination from the destination address of the frame 8 (step 1).
0), the current date, day of the week, and time are acquired from the date, day of the week, and time generator 5 (step 11).

Next, the router function unit 2 searches the time access control table 4, and as shown in FIG. 4, the time access control table 4 has ten entries. The router function unit 2 first takes out the first entry (step 12), and if the condition is registered (step 13), acquires the access control condition specified by the entry and the date / day / day / time generator 5 first. The current date / day / day / time and the source / destination address of frame 8 are compared (step 14). However, since there is no date in the access control condition specified by the entry, date comparison is not performed.

In this case, the access control condition, the current time,
Since the respective conditions of the address designated in the frame and the frame do not match (step 15), the router function unit 2 takes out the next entry of the time access control table 4 (step 16). If the condition is registered (step 13), the same processing as in the case of the first entry is performed for the second entry.

In this way, the last entry is checked, and if there is no entry that matches the condition (step 13), the router function unit 2 determines that the access is permitted, and the frame 8 is set as the routing destination. (Step 18). In this case, in the computer network system of this embodiment, since the routing destination is the computer network 6c, the frame 8 is eventually transmitted to the computer network 6c and the terminal 7f receives the frame 8.

When access is not permitted A case where the terminal 7a transmits a frame to the terminal 7f at 10 pm on Saturday will be described with reference to the flowchart of FIG. First, the terminal 7a transmits the frame 8 by setting its own address as the source address and the terminal address of the terminal 7f as the destination address. When the local interface unit 3a of the router device 1 receives the frame 8 (step 9), the router function unit 2 determines the routing destination from the destination address of the frame 8 (step 1).
0), the current date, day of the week, and time are acquired from the date, day of the week, and time generator 5 (step 11).

Next, the router function unit 2 searches the time access control table 4, and as shown in FIG. 4, the time access control table 4 has 10 entries. The router function unit 2 checks whether the conditions match from the first entry in the same procedure as in the above case. In this case, the condition matches in the fifth entry (step 15),
The router function unit 2 determines that the access is prohibited and discards the frame 8 (step 17). Therefore, the terminal 7f does not receive the frame 8.

Embodiment 2 FIG. 5 is a second embodiment of the computer network connection apparatus according to the present invention, in which access control is performed by designating a group number to which a terminal belongs, instead of designating a terminal address as an access control condition. It is a block diagram of an example router device. Incidentally, the same or corresponding parts as those of the conventional router device are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 5, the router device 1 of the second embodiment has a group registration table 20 in addition to the router function unit 2 and the time access control table 4. Further, FIG. 6 shows the router function unit 2 of the second embodiment shown in FIG.
3 is a flowchart showing the operation contents of FIG.

In the router device 1 of the second embodiment, in the computer network system shown in FIG. 2, each terminal is divided into groups, that is, the terminal address is registered in the group in the following manner. First, the terminals 7a and 7b are registered in the group number 1, the terminals 7c and 7d are registered in the group number 2, and the group number 3 is registered.
The terminal 7e and the terminal 7f are registered in. Therefore, the contents of the group registration table 20 in this case are as shown in FIG. In the figure, each entry forming the group registration table 20 indicates a terminal address and a group number to which the terminal belongs. That is, for example, in the first entry, it can be seen that the terminal 7a belongs to the group number 1.

Further, in the router device 1 of the second embodiment,
Access control between groups is performed as follows. From Monday to Friday, regardless of the date, Group 1 and Group 3 are allowed to access each other from 9 am to 5 pm. However, from 5 pm to 9 am the next day, group 1 and group 3 are not allowed to access each other. That is, neither access from group 1 to group 3 nor access from group 1 to group 3 is prohibited. Further, regardless of the date, the group 1 and the group 3 cannot access each other at all times on Saturday and Sunday. However, the access except between the group 1 and the group 3 is always permitted regardless of the date, the day of the week, and the time.

FIG. 7 shows the contents of the time access control table 4 which stores the control conditions when the above access control is performed. In the figure, time access control table 4
Each of the entries that make up is a condition for time access control. Since the router device 1 of the second embodiment performs access control regardless of the date, the access control conditions include the group number to which the source terminal of the frame belongs (source group number) and the group number to which the destination terminal belongs ( Destination group number), day of the week, and time shall be specified.

In FIG. 7, the item in the first column of each entry of the time access control table 4 is the condition specification of the day of the week and the time, and specifies the day of the week and the time zone in which access is prohibited. The item in the second column of each entry of the time access control table 4 is a condition designation of a source group number and a destination group number of a frame whose access is prohibited,
The left side of the arrow shown in the figure is the source group number, and the right side of the arrow is the destination group number. Access of a condition that matches any entry of the time access control table 4 is prohibited, and other access is permitted. Therefore, as many entries as the number of conditions for prohibiting access are registered.

When Access is Allowed A case where the terminal 7a transmits a frame to the terminal 7f at 11:00 AM on Wednesday will be described with reference to the flowchart of FIG. The terminal 7a sets its own address as the source address and the address of the terminal 7f as the destination address, and transmits the frame 8. When the local interface unit 3a of the router device 1 receives the frame 8 (step 21), the router function unit 2 determines the routing destination from the data of the frame 8 (step 22) and determines the current date / time.
The day of the week / time is acquired from the date / day of the week / time generator 5 (step 23). Further, the router device 1 refers to the group registration table 20 to obtain the source group number to which the source address of the frame 8 belongs and the destination group number to which the destination address belongs (step 24). In this case, since the source address of the frame 8 is the terminal 7a, the source group number is 1, and similarly, the destination address is the terminal 7f, so the destination group number is 3.

Next, the router function unit 2 searches the time access control table 4, and as shown in FIG. 4, the time access control table 4 has ten entries. The router function unit 2 first takes out the first entry (step 25), and if the condition is registered (step 26), the access control condition specified by the entry, the current date / day / time / time, and the frame transmission source. The group number and the destination group number are compared (step 27). In this case, since the condition specified by the entry has no date, the date is not compared. Since the conditions do not match (step 28), the router function unit 2 fetches the next entry in the time access control table 4 (step 29). If the condition is registered (step 26), the same processing as in the case of the first entry is performed for the second entry.

In this way, the last entry is checked, and if there is no entry that matches the condition (step 26), the router function unit 2 determines that the access is permitted, and the frame 8 is set as the routing destination. (Step 31). In this case, in the computer network system of this embodiment, since the routing destination is the computer network 6c, the frame 8 is eventually transmitted to the computer network 6c and the terminal 7f receives the frame 8.

When Access is Not Allowed A case where the terminal 7a transmits a frame to the terminal 7f at 10 pm on Saturday will be described with reference to the flowchart of FIG. The terminal 7a sets its own address as the source address and the address of the terminal 7f as the destination address, and transmits the frame 8. When the local interface unit 3a of the router device 1 receives the frame 8 (step 21), the router function unit 2 determines the routing destination (step 22), and sets the current date / day / time to the date / day / time generator 5. (Step 23). Then, the group registration table 20 is referenced to acquire the source group number to which the source address of the frame belongs and the destination group number to which the destination address belongs (step 24). In this case, since the source address is the terminal 7a, the source group number is 1, and the destination address is the terminal 7f, so the destination group number is 3.

Next, the router function unit 2 searches the time access control table 4, and as shown in FIG. 4, the time access control table 4 has ten entries. The router function unit 2 checks whether the conditions match from the first entry in the same procedure as in the above case. In this case, the condition matches in the fifth entry (step 28),
The router function unit 2 determines that the access is prohibited and discards the frame 8 (step 30). Therefore, the terminal 7f does not receive the frame 8.

Embodiment 3 FIG. 9 is a block diagram of a router device 1 which is a third embodiment of the computer network connection device according to the present invention. Incidentally, the same or corresponding parts as those of the conventional router device are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 9, the router device 1 of the third embodiment has a router function unit 2, a time access control table 4,
In addition to the date / day of the week / time generator 5 and the like, the remote interface unit 33 for interconnecting other router devices constituting the computer network system with the two dedicated lines 36a and 36b and the traffic of the dedicated lines 36a and 36b. Traffic measuring device 34a, 34 for measuring
b. Further, the router device 1 according to the third embodiment has a high traffic threshold for determining the start of use of the backup dedicated line and a low traffic threshold for determining stop of use of the backup dedicated line. Has a traffic threshold table 35 for storing

FIG. 10 is a block diagram of a computer network system using the router device 1 of the third embodiment shown in FIG. In the figure, the computer network system of the present embodiment includes router devices 1a and 1a.
b, a computer network 6a, 6b, 6c connected to the router device 1a, a computer network 6d connected to the router device 1b, and terminals 7a to 7f connected to the computer network 6a, 6b, 6c.
And a terminal 7 connected to the computer network 6d
g, 7h and dedicated lines 36a, 36b for connecting the router devices 1a and 1b to each other.

Further, FIG. 11 is a flow chart showing the operation contents of the router function unit 2 of the third embodiment shown in FIG.

In the third embodiment, a case will be described in which a frame is transmitted to a router device 1b at a remote place by using a dedicated line in order to route the frame received by the router device 1a. Dedicated line is 36a, 36b 2
There is a book, and the dedicated line 36a is usually used and the dedicated line 36b is a backup dedicated line. Further, it is assumed that the dedicated lines 36a and 36b have no trouble. The capacities of the dedicated lines 36a and 36b (the number of bits that can be processed in one second) are 64 kbits / sec, and the traffic measuring devices 34a and 34b connected to the dedicated lines are 1
It shall output the data transmission amount per second. Further, it is assumed that a value of 50 kbit / sec as the high traffic threshold value and a value of 30 kbit / sec as the low traffic threshold value are registered in the traffic threshold value table 35.
Therefore, the contents of the traffic threshold table 35 are shown in FIG.
It becomes as shown in 2.

The access control conditions are not specified. Further, the router function unit 2 stores whether or not the backup dedicated line 36b is used, and in the initial state, the dedicated line 36b is stored as unused.

When the traffic on the leased line 36a is small: The output of the traffic measuring device 34a on the leased line 36a is 2
The case of 0 kbit / sec will be described based on the flowchart of FIG. Router function unit 2 is frame 8
(Step 37), the router function unit 2 determines the routing destination (step 38).

Next, the router function unit 2 searches the time access control table 4 and the time access control table 4 is searched.
Has no entries in. The router function unit 2 first tries to take out the first entry (step 39), but since the entry is not registered in the access control table 4 (step 40), the router function unit 2 is permitted to access. Therefore, the frame 8 is transmitted to the routing destination.

In this case, since the routing destination is the dedicated line (step 45), it is confirmed whether the dedicated line 36b is currently used (step 46). Router function part 2
Stores that the dedicated line 36b is not used, it is confirmed whether the normally used dedicated line 36a can be used (step 52). Since the leased line 36a can be used, the router function unit 2 acquires the traffic measurement value from the traffic measurement device 34a and the high traffic threshold value from the traffic threshold value table 35 (step 53). The traffic measurement is 20 kbit / s and the high traffic threshold is 50 kbit / s. When the traffic measurement value and the high traffic threshold value are compared (step 54), the traffic measurement value is smaller than the high traffic threshold value, so the router function unit 2 determines that the traffic on the leased line 36a is small, and the leased line 36a is connected to the leased line 36a. Frame 8
Is transmitted (step 56).

When the traffic of the dedicated line 36a is large: The traffic volume of the dedicated line 36a increases, and the dedicated line 36a
The output of the traffic measuring device 34a of a is 52 kbit /
A case in which the number of seconds is reached will be described based on the flowchart of FIG. When the router function unit 2 receives the frame 8 (step 37), it determines the routing destination (step 38).

Next, the router function unit 2 searches the time access control table 4 and the time access control table 4 is searched.
Has no entries in. The router function unit 2 first tries to take out the first entry (step 39), but since the entry is not registered in the access control table 4 (step 40), the router function unit 2 is permitted to access. Therefore, the frame 8 is transmitted to the routing destination.

In this case, since the routing destination is the dedicated line (step 45), it is confirmed whether the dedicated line 36b is currently used (step 46). Router function part 2
Stores that the dedicated line 36b is not used, it is confirmed whether the normally used dedicated line 36a can be used (step 52). Since the leased line 36a can be used, the router function unit 2 acquires the traffic measurement value from the traffic measurement device 34a and the high traffic threshold value from the traffic threshold value table 35 (step 53). The traffic measurement is 52 kbit / s and the high traffic threshold is 50 kbit / s. When the traffic measurement value is compared with the high traffic threshold value (step 54), the traffic measurement value is larger than the high traffic threshold value, so the router function unit 2 judges that the traffic on the leased line 36a is large, and the backup function is dedicated. Line 3
It is decided to use 6b (step 55). Then, the router function unit 2 transmits the frame 8 to the leased line 36b (step 51).

By using the dedicated line 36b, the dedicated line 3
When the traffic of 6a becomes small When the number of cases of using the leased line 36b increases, the traffic volume of the leased line 36a decreases. As a result, a case where the output of the traffic measuring device 34a becomes 27 kbit / sec will be described based on the flowchart of FIG. When the router function unit 2 receives the frame 8 (step 37), the router function unit 2 determines the routing destination (step 38).

Next, the router function unit 2 searches the time access control table 4 and the time access control table 4 is searched.
Has no entries in. The router function unit 2 first tries to take out the first entry (step 39), but since the entry is not registered in the access control table 4 (step 40), the router function unit 2 is permitted to access. Therefore, the frame 8 is transmitted to the routing destination.

In this case, since the routing destination is the dedicated line (step 45), it is confirmed whether the dedicated line 36b is currently used (step 46). Router function part 2
Remembers that he is using the leased line 36b,
Check if the leased line 36b is available (step 4)
7). Since the leased line 36b can be used, the router function unit 2 obtains the traffic measurement value from the traffic measurement device 34a and the low traffic threshold value from the traffic threshold value table 35 (step 48). The traffic measurement is 27 kbit / s and the low traffic threshold is 30 kbit / s. When the traffic measurement value and the low traffic threshold value are compared (step 49), the traffic measurement value is smaller than the low traffic threshold value, so the router function unit 2 judges that the traffic on the leased line 36a is small, and the backup function is used for backup. The use of the private line 36b is stopped (step 50), and the frame 8 is transmitted to the private line 36a (step 56).

Embodiment 4 FIG. 13 is a block diagram of a router device 1 which is a fourth embodiment of a computer network connection device according to the present invention. Incidentally, the same or corresponding parts as those of the conventional router device are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 13, the router device 1 of the fourth embodiment has a router function unit 2 and a remote interface unit 3.
3, the local interface units 3a, 3b, 3c, etc., as well as the test frame storing the current time, the dedicated line 36
a test frame transmission device 59 that periodically transmits to the a and 36b, and a test frame inspection device 60 that receives the test frame from the partner router device and calculates the time difference between the time information stored in the test frame and the current time. is doing. Further, the router device 1 of the fourth embodiment compares the time difference which is the output information of the test frame inspection device 60 corresponding to the two leased lines 36a and 36b, and determines the leased line with a small time difference as the currently used leased line. It has a dedicated use line storage unit 61 for storing.

FIG. 14 is a block diagram of a computer network system using the router device 1 of the fourth embodiment shown in FIG. In the figure, the computer network system of the present embodiment includes a router device 1a,
1b, a computer network 6a, 6b, 6c connected to the router device 1a, a computer network 6d connected to the router device 1b, and terminals 7a to 7 connected to the computer networks 6a, 6b, 6c.
f, terminals 7g and 7h connected to the computer network 6d, and dedicated lines 36a and 36b for mutually connecting the router devices 1a and 1b, respectively.

Operation of Test Frame Transmitting Device 59 The test frame transmitting device 59 of the fourth router device 1 has three
A test frame shall be transmitted every 0 seconds. Figure 15
9 is a flowchart showing the operation contents of the test frame transmitting device 59. The operation of the test frame transmitter 59 will be described below with reference to the flowchart shown in FIG.

First, since the test frame transmitting device 59 stores the transmission time every time the test frame is transmitted, it stores the time when the last (previous) test frame was transmitted. Then, the test frame transmitting device 59 refers to the built-in clock to judge whether 30 seconds or more have passed since the last test frame transmission (step 64). If 30 seconds or more has not elapsed, this determination operation is repeated. Thirty
If more than a second has passed, a new test frame that stores the current time is newly created, and the leased line 36a and the leased line 36b are
From the opposite router device 1b (step 6)
5). The following description will be given assuming that the current time is 10:10:10. As a result of the above operation, the test frame 62a is transmitted on the leased line 36a and the test frame 62b is transmitted on the leased line 36b.

In the computer network system of the fourth embodiment, the dedicated line 36a is the dedicated line 3
The delay is smaller than that of 6b, the test frame 62a arrives from the router device 1a to the router device 1b in 1 second, and the test frame 62b is transferred from the router device 1a to the router device 1b.
It shall arrive in seconds.

Operation of Test Frame Inspection Device 60 FIG. 16 is a flowchart showing the operation contents of the test frame inspection device 60 shown in FIG. The operation of the test frame inspection device 60 in the router device 1b will be described below with reference to the flowchart shown in FIG.

The test frame inspection device 60 waits until the test frame is received from either of the two dedicated lines 36a and 36b. In the computer network system of the fourth embodiment, the dedicated line 36a is the dedicated line 3
Since the delay is smaller than 6b, the test frame 62a on the leased line 36a is received first (step 68). Therefore, the test frame inspection device 60 acquires the current time from the clock of the router device 1b itself (step 69), and acquires the transmission time from the test frame 62a (step 70). The current time of the router device 1b is 10:20:30
Seconds, and the transmission time of the test frame 62a is 10:01
It is assumed that it is 0 minutes and 10 seconds. Test frame inspection device 60
Next calculates the difference between the current time and the transmission time and stores it as the time difference of the leased line 36a (step 71). Therefore, the time difference of the dedicated line 36a is 10 minutes and 20 seconds.

Next, the test frame inspection device 60 waits for receiving a test frame from the leased line 36b (step 72). When the test frame 62b is received, the current time is acquired from the clock of the own router device 1b as in the case of the test frame 62a (step 7
3), the transmission time is acquired from the test frame 62a (step 74). Since the test frame 62b arrives one second later than the test frame 62a, the router device 1
The current time of b is 10:20:31, test frame 6
The transmission time of 2b is 10:10:10. The test frame inspection device 60 then calculates the difference between the current time and the transmission time and stores it as the time difference of the leased line 36b (step 75). Therefore, the time difference of the leased line 36b is 10 minutes 21 seconds.

As a result of the above operation, the two dedicated lines 36a,
Since the time difference of each of 36b is known, the test frame inspection device 60 compares the two time differences (step 7).
6). The time difference of the leased line 36a is 10 minutes 20 seconds,
Since the time difference of the leased line 36b is 10 minutes and 21 seconds, the time difference of the leased line 36a is smaller. Therefore, the test frame inspection device 60 determines the dedicated line to be used as the dedicated line 36a (step 78). Based on this determination, the test frame inspection apparatus 60 stores the dedicated use line in the dedicated use line storage unit 61 as the line 36a (step 79).

Operation of Router Function Unit 2 FIG. 17 is a flowchart showing the operation contents of the router function unit 2 of the fourth embodiment. Hereinafter, based on the flowchart of FIG. 17, the router device 1a set at a remote place for routing the frame received by the router device 1b.
First, a case where a frame is transmitted using the dedicated lines 36a and 36b will be described.

When the router function unit 2 receives the frame (step 80), it determines the routing destination based on the frame data (step 81). In this case, since the routing destination is the dedicated line (step 82), the router function unit 2 acquires the dedicated use line from the dedicated use line storage unit 61 (step 83). Since the private line 36a is currently stored in the private line storage unit 61 as a private line, the router function unit 2 transmits a frame to the private line 36a (step 84).

Embodiment 5 FIG. 18 is a block diagram of a router device 1 which is a fifth embodiment of a computer network connection device according to the present invention. Incidentally, the same or corresponding parts as those of the conventional router device are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 18, the router device 1 of the fifth embodiment includes a router function unit 2 and a test frame transmission device 5.
9. In addition to the test frame inspection device 60, the dedicated line storage unit 61, etc., the time difference which is the output information of the test frame inspection device 60 calculated based on the test frame received when there is no other traffic is stored as the reference time difference. It has a reference time difference storage unit 87 for performing.

Operation of Test Frame Inspection Device FIG. 19 shows a test frame inspection device 60 of the fifth embodiment.
3 is a flowchart showing the operation contents of FIG. Below, FIG.
The operation of the test frame inspection device 60 in the router device 1b will be described based on the flowchart of FIG.

Test frame inspection apparatus 6 of the fifth embodiment
0 receives the test frame, acquires the current time from the clock of the router device itself, acquires the transmission time in the test frame, calculates the difference between the current time and the transmission time, and calculates the time difference and the reference time difference storage unit 87. Calculate the difference from the reference time difference stored in. This difference is the absolute time difference. The reference time difference is registered when the first test frame is received after the power of the router device is turned on. The operation will be described below.

In the computer network system of the fifth embodiment, the dedicated line 36a is the dedicated line 3
The delay is smaller than 6b, the delay of the leased line 36a is 1 second,
It is assumed that the delay of the private line 36b is 5 seconds.

Operation of the test frame inspection device 60 when the reference time difference is not stored After turning on the power of the router devices 1a and 1b, the router device 1a
When the router transmits the test frame to the router device 1b, the router device 1
The operation of the test frame inspection device 60 of b will be described.

Test frame inspection apparatus 6 of the fifth embodiment
0 waits until the test frame is received from either of the two dedicated lines 36a and 36b. In the computer network system of the fifth embodiment, the leased line 36a has a smaller delay than the leased line 36b.
The test frame 62a on 6a is received first (step 89). Therefore, the test frame inspection device 60 acquires the current time from the clock of the router device 1b itself (step 90), and acquires the transmission time from the test frame 62a (step 91). The current time of the router device 1b is 1
It is assumed that the time is 0:20:30 and the transmission time of the test frame 62a is 10:10:10.

Next, the test frame inspection device 60 calculates the difference between the current time and the transmission time (step 92). The time difference of the leased line 36a is 10 minutes and 20 seconds. After that, the test frame inspection device 60 checks the reference time difference storage unit 87 whether the reference time difference of the leased line 36a is stored (step 93). In this case, the router device 1
Since it is the first test frame after the power of b is turned on, the reference time difference storage unit 87 does not store the reference time difference. Therefore, the test frame inspection device 60 stores the time difference of 10 minutes and 20 seconds as the time difference of the leased line 36a (step 94). Then, the reference time difference of the leased line 36a is acquired from the reference time difference storage unit 87 (step 9).
5) The absolute time difference, which is the difference between the reference time difference and the previously obtained time difference, is calculated and stored (step 96). Therefore, of course, immediately after the power is turned on, the absolute time difference of the leased line 36a is 0 seconds.

Next, the test frame inspection device 60 waits for receiving a test frame from the leased line 36b (step 97). When the test frame 62b is received, as in the case of the test frame 62a, the current time is acquired from the clock of the router device 1b itself (step 9).
8) The transmission time is acquired from the test frame 62a (step 99). Since the test frame 62b arrives 4 seconds later than the test frame 62a, the test frame transmission time is 10:10:10 and the current time of the router device 1b is 10:20:34.

Next, the test frame inspection device 60 calculates the difference between the current time of the router device and the test frame transmission time (step 100). The time difference of the leased line 36b is 10 minutes and 24 seconds. Then, the test frame inspection device 60 checks the reference time difference storage unit 87 whether the reference time difference of the leased line 36b is stored (step 10).
1). In this case, the reference time difference is not stored because it is the first test frame after the power of the router device 1b is turned on. Therefore, the test frame inspection device 60
Stores the time difference of 10 minutes and 24 seconds as the time difference of the leased line 36b (step 102). Then, leased line 36b
Is acquired from the reference time difference storage unit 87 (step 103), and the absolute time difference, which is the difference between the reference time difference and the previously obtained time difference, is calculated and stored (step 10).
4). Therefore, of course, immediately after the power is turned on, the absolute time difference of the leased line 36b is 0 seconds.

As a result of the above operation, the two dedicated lines 36a,
Since each time difference of 36b is known, the test frame inspection device 60 compares the two time differences (step 1).
05). The time difference on the leased line 36a is 0 seconds, and the time difference on the leased line 36b is also 0 seconds. Therefore, the test frame inspection device 60 determines the dedicated line to be used as the dedicated line 36a (step 107). After that, the dedicated line 36a is stored in the use dedicated line storage unit 61 (step 108).

Operation of Test Frame Inspection Device 60 When Reference Time Difference is Stored Next, a case where the delay state of the leased lines 36a and 36b has changed since the router devices 1a and 1b started the operation will be described. Based on the flowchart of 19, the router device 1b
The operation of the test frame inspection device 60 will be described. Here, it is assumed that the delay of the dedicated line 36a is increased by 3 seconds to 4 seconds, and the delay of the dedicated line 36b is increased by 1 second to 6 seconds.

As described above, in the leased lines 36a and 36b, the delays when there is no traffic are 1 second and 5 seconds, respectively. At present, the load on the dedicated line 36a is higher (busier) due to the change in the delay state of the dedicated lines 36a and 36b, and thus the delay on the dedicated line 36a is larger. Nevertheless, the total delay time including the delay before that is 1 + 3 = 4 seconds for the leased line 36a and 5 + 1 for the leased line 36b.
= 6 seconds, which means that the leased line 36b has a larger delay. The operation of the test frame inspection device 60 in this situation will be described.

The test frame inspection device 60 waits until the test frame is received from which of the two dedicated lines 36a and 36b. In the computer network system of the fifth embodiment, the dedicated line 36a is the dedicated line 3
Since the delay is smaller than 6b, the test frame 62a on the leased line 36a is received first (step 89). Therefore, the test frame inspection device 60 acquires the current time from the clock of the router device 1b itself (step 90), and acquires the transmission time from the test frame 62a (step 91). The test frame transmission time is 10:30:30
Seconds, and the current time of the router device 1b is 10: 40: 5.
Suppose it is 3 seconds.

Next, the test frame inspection device 60 calculates the difference between the current time and the transmission time (step 92). The time difference of the leased line 36a is 10 minutes and 23 seconds. Then, the test frame inspection device 60 checks the reference time difference storage unit 87 whether the reference time difference of the dedicated line 36a is stored (step 93). In this case, since the reference time difference is already stored in the reference time difference storage unit 87, the test frame inspection apparatus 60 acquires the reference time difference of the leased line 36a from the reference time difference storage unit 87 (step 95).
The absolute time difference, which is the difference between the reference time difference and the time difference, is calculated and stored (step 96). At this point, the leased line 36
Since the reference time difference of a is 10 minutes and 20 seconds, the absolute time difference is 3 seconds.

Next, the test frame inspection device 60 waits for reception of a test frame from the leased line 36b (step 97). When the test frame 62b is received, as in the case of the test frame 62a, the current time is acquired from the clock of the router device 1b itself (step 9).
8) The transmission time is acquired from the test frame 62a (step 99). Since the test frame 62b arrives one second later than the test frame 62a, the test frame transmission time is 10:30:30 and the current time of the router device 1b is 10:40:55.

Next, the test frame inspection device 60 calculates the difference between the current time and the transmission time (step 100). The time difference of the leased line 36b is 10 minutes and 25 seconds. Then, the test frame inspection device 60 checks the reference time difference storage unit 87 whether the reference time difference of the leased line 36b is stored (step 101). In this case, since the reference time difference is already stored, the reference time difference of the leased line 36b is acquired from the reference time difference storage unit 87 (step 10).
3) The absolute time difference, which is the difference between the reference time difference and the time difference, is calculated and stored (step 104). At this point, the absolute time difference of the leased line 36b is 10 minutes and 24 seconds, so the absolute time difference is 1 second.

As a result of the above operation, the two dedicated lines 36a,
Since each time difference of 36b is known, the test frame inspection device 60 compares the two time differences (step 1).
05). The time difference of the leased line 36a is 3 seconds, and the time difference of the leased line 36b is 1 second. Therefore, the test frame inspection device 60 determines that the dedicated line 36b has a lighter load, and the test frame inspection device 60 determines the dedicated line to be used as the dedicated line 36b (step 106). After that, the private line 36b is stored in the private line storage unit 61 (step 108).

Although the router device has been described as the embodiment of the computer network connection device of the present invention, it is obvious that the same can be applied to the bridge device.

[0114]

As described above, according to the computer network connection apparatus of the present invention, when the router function unit receives the frame, it searches the time access control table to determine the date / day / day / time information and the terminal information. It is configured so that access control between terminals can be performed by address information, and a plurality of terminal addresses are divided into groups and the correspondence between terminals and group numbers is registered in the group registration table. Further, since the access between groups can be controlled by the group number information, there is an effect that flexible access control that leads to automation and labor saving becomes possible.

Further, according to the computer network connection apparatus of the present invention, the traffic measuring apparatus measures the traffic of the normally used leased line, and the traffic value and the high traffic threshold value stored in the traffic threshold value table, and By comparing with the low traffic threshold, when the measured value of the traffic measuring device exceeds the high traffic threshold, the dedicated leased line for backup is started, and the measured value of the traffic measuring device is changed to the low traffic threshold. Since the configuration is such that the use of the backup dedicated line is stopped when it becomes lower, there is an effect that the lines can be accurately switched and the load can be distributed between the dedicated lines.

Further, according to the computer network connection apparatus of the present invention, the test frame is periodically transmitted to the dedicated line, and the test frame transmitted from the partner apparatus is received and the time information stored in the test frame is stored. Since the time difference between the current times is calculated, the time difference between the two leased lines is compared, and the leased line with the smallest time difference is selected and used as the currently used leased line, the load of the leased line must be effectively distributed. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a block diagram of a router device that is a first embodiment of a computer network connection device according to the present invention.

FIG. 2 is a block diagram of a computer network system using the router device of the first embodiment.

FIG. 3 is a flowchart showing the operation contents of the router function unit 2 of the first embodiment.

FIG. 4 is a diagram showing the contents of access control conditions of a temporal access control table 4 of the first embodiment.

FIG. 5 is a block diagram of a router device that is a second embodiment of the computer network connection device according to the present invention.

FIG. 6 is a flowchart showing the operation contents of the router function unit 2 of the second embodiment.

FIG. 7 is a second part of the temporal access control table 4 shown in FIG.
It is a figure which shows the content of the access control conditions of.

FIG. 8 is a diagram showing the contents of a group registration table 20 of the router device of the second embodiment.

FIG. 9 is a block diagram of a router device which is a third embodiment of the computer network connection device according to the present invention.

FIG. 10 is a block diagram of a computer network system using a router device of a third embodiment.

FIG. 11 is a flowchart showing the operation contents of the router function unit 2 of the third embodiment.

FIG. 12 is a diagram showing the contents of a traffic threshold table 35 of the router device of the third embodiment.

FIG. 13 is a block diagram of a router device which is a fourth embodiment of the computer network connection device according to the present invention.

FIG. 14 is a block diagram of a computer network system using a router device of a fourth embodiment.

FIG. 15 is a test frame transmitter 59 of the fourth embodiment.
3 is a flowchart showing the operation contents of FIG.

FIG. 16 is a test frame inspection device 60 of the fourth embodiment.
3 is a flowchart showing the operation contents of FIG.

FIG. 17 is a flowchart showing the operation contents of the router function unit 2 of the fourth embodiment.

FIG. 18 is a block diagram of a router device which is a fifth embodiment of the computer network connection device according to the present invention.

FIG. 19 is a test frame inspection device 60 of the fifth embodiment.
3 is a flowchart showing the operation contents of FIG.

FIG. 20 is a block diagram showing an internal configuration of a conventional router device.

FIG. 21 is a block diagram of a computer network system using a conventional router device.

FIG. 22 is a flowchart showing operation contents of a router function unit 110 of a conventional router device.

FIG. 23 is a diagram showing the contents of an access control table section 111 of a conventional router device.

[Explanation of symbols]

 2 router function unit 4 hour access control table 5 date / day of the week / time generator 20 group registration table 34a, 34b traffic measuring device 35 traffic threshold table 59 test frame transmitting device 60 test frame checking device 61 dedicated leased line storage unit 87 Reference time difference storage section

Claims (5)

[Claims] 1. A computer network connecting device for connecting a plurality of computer networks for connecting a plurality of terminals to each other, and a date / day / time generating means for generating a current date / day / day / time and date / day / hour / time or A time access control table for performing access control between terminals based on these combination information and terminal address information, output information from date / day / time generating means, terminal address of received frame from computer network, and the above-mentioned A computer network connection device comprising: a control unit that controls access between different computer network terminals based on the contents of the time access control table. 2. A computer network connection device for connecting a plurality of computer networks for connecting a plurality of terminals to each other, and a group registration table for registering correspondence between terminals and group numbers by dividing a plurality of terminal addresses into groups. Date / day of the week / time generating means for generating the current date / day of the week / time, time access control table for controlling access between groups by date / day of the week / time or combination information thereof and group number information, date A control means for controlling access between different computer network terminals based on the output information from the day / time generating means, the terminal address of the received frame from the computer network, and the contents of the time access control table Computer network Network connection devices. 3. A computer network connection device for connecting a plurality of computer networks for connecting a plurality of terminals to each other, and a dedicated connection for connecting another computer network connection device constituting a computer network system by two dedicated lines. Line connection means, traffic measurement means to measure the traffic of the leased line, date / day / time / time generation means to generate the current date / day / time / time, date / day / time or combination information, and backup A traffic threshold table for storing a high traffic threshold for judging the start of use of the leased line and a low traffic threshold for judging the suspension of use of the backup leased line is provided. Uses one of the dedicated lines to output traffic measurement means. When the information exceeds the high traffic threshold in the traffic threshold table, the backup dedicated line is activated, and the output information of the traffic measuring means becomes lower than the low traffic threshold in the traffic threshold table. A computer network connection device comprising control means for stopping use of a dedicated backup line in some cases. 4. A computer network connection device for connecting a plurality of computer networks for connecting a plurality of terminals to each other, which is dedicated for interconnecting other computer network connection devices constituting a computer network system by two dedicated lines. Line connection means, date / day / time generation means for generating the current date / day / time, test frame transmission means for periodically transmitting a test frame that stores the current time to a dedicated line, and test frame reception Then, the test frame inspection means for calculating the time difference between the time information stored in the test frame and the current time is compared with the time difference output from the two test frame inspection means corresponding to the two leased lines. Use only times to store a small leased line as the currently used leased line Comprising a storage unit, further, a computer network connection device characterized by comprising a control means for selecting a smaller dedicated line delay as the current use dedicated line of the two leased lines. 5. A computer network connection device for connecting a plurality of computer networks for connecting a plurality of terminals to each other, which is dedicated for interconnecting another computer network connection device constituting a computer network system by two dedicated lines. Line connection means, date / day / time generation means for generating the current date / day / day / time, traffic measurement means for measuring the traffic on the dedicated line, and a test frame that stores the current time on the dedicated line periodically Test frame sending means to send, test frame checking means to receive the test frame and calculate the time difference between the time information stored in the test frame and the current time, and calculate based on the test frame received when there is no other traffic Of the test frame inspection means Reference time difference storage means for storing the time difference as force information as a reference time difference, comparing the time difference as output information of the test frame inspection means with the time difference as output information of the reference time difference storage means,
A dedicated leased line storage means for storing a leased line with a small time difference as the currently used leased line is provided, and a control means for selecting a leased line with a small delay among the two leased lines as the currently used leased line. Characteristic computer network connection device.