JPH0548612A - Inter-lan connecting device - Google Patents

Abstract

PURPOSE:To improve the performance of a device and to improve the reliability by improving the throughput of communication of the device and suppressing the waste of calculation of addresses of an address conversion table and its memory capacity. CONSTITUTION:The device is provided with route information 11 used for registering the transmission path of a frame received from a trunk line LAN 15 or branch lines LAN 17, 19, an address calculation means 3 calculating the address of a transmission path destination of a frame registered in the route information to be received, a discrimination means 3 discriminating the presence of the route information from the address conversion table represented by the address calculated by the address calculating means 3, and a means 3 sending the frame received to a transmission path represented by the route information when the registration is present thereon based on the discriminating means 3 and implementing multiple address communication of the received frame when no registration is present thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a LAN-to-LAN connecting device for connecting LANs to each other, and more particularly to a LAN for shortening address search time and improving throughput of data communication.
Inter-connection device.

[0002]

2. Description of the Related Art In recent years, a local area network (hereinafter referred to as L
It is called AN. ) Is widespread.

An L connecting a branch line LAN of a lower structure LAN of a LAN in which a bus type and a ring type, which are wiring forms of the LAN described above, are hierarchically structured, to a trunk LAN of an upper structure LAN.
The operation of the inter-AN connection device will be described with reference to the flowcharts of FIGS. 6 and 7.

First, when a frame shown in FIG. 8A is received from a branch LAN, an inter-LAN connecting device (hereinafter referred to as an adapter) extracts the source address (SA) set in the received frame. The address of the address conversion table is calculated from the fetched source address by the HASH function (steps 300 to 320).

The adapter determines whether or not the calculated address is registered in the address conversion table. If the calculated address is not registered in the address conversion table, the process proceeds to step 340, and if it is registered in the address conversion table, the process proceeds to step 400 (step 330).

At step 340, the adapter registers the calculated address in the address conversion table, extracts the destination address (DA) of the received frame, and HA.
The address is calculated by the SH function. When the calculated address is registered in the address conversion table, the adapter fetches the adapter address and receives it.
An adapter address (DA) indicating a destination, an adapter adapter (SA) indicating a transmission source, and a control unit are added to the head of the frame received from the device, and the frame is transmitted to the trunk LAN. On the other hand, if it is not registered, the adapter sets an address to be sent by simultaneous broadcast on the trunk LAN (steps 340 to 390).

On the other hand, when proceeding to step 400, the adapter reads another address from the address translation table, sets the pointer of the address translation table if the read address is not registered, and returns to step 340. On the other hand, if the other address is already registered, the adapter returns to step 350 for checking the overflow of the address conversion table and fetching the destination address when overflow occurs, and returns to step 330 when not overflowing (steps 400 to 430).

Next, the case of reception from the main LAN will be described with reference to the flowchart of FIG.

When a frame is received from the trunk LAN, the adapter reads the source address set in the frame and calculates the address of the address conversion table. The adapter judges whether the calculated address is registered, and if not registered, registers the calculated address (steps 440 to 480).

On the other hand, if the calculated address is registered, the adapter ends the process when the address is the same, and searches another address in the address conversion table if the address is not the same. After the search, the adapter ends the process if it is not an overflow of the address conversion table, and judges whether it is the same address at the time of overflow.
Return to 90 (steps 490-510).

[0011]

However, the conventional LAN-to-LAN connecting device calculates the address by the HASH function from the source address set in the received frame, and further, the overlap by the calculated address occurs. There is a problem that the communication throughput is lowered.

Further, since the source address and the pointer due to the duplication of the source address are registered in the address translation table, the size per entry becomes large, and there is a problem that the number of adapters that can be registered in the address translation table is limited.

The present invention has been made in order to solve such a conventional problem, and an object thereof is to improve the communication throughput of the device, to calculate the address of the address conversion table and to waste the memory capacity. It is an object of the present invention to provide a LAN-to-LAN connecting device that improves the device performance and reliability by suppressing the above.

[0014]

To achieve the above object, the present invention provides route information for registering a transmission route of a frame received from a trunk LAN or a branch LAN, and
Address calculating means for calculating the address of the transmission route destination of the received frame registered in this route information,
Judgment means for judging the presence or absence of the route information in the address conversion table indicated by the address calculated by the address calculation means, and transmitting the received frame to the transmission path indicated by the route information when the judgment means determines that there is registration. And a means for broadcasting the received frame when the registration is absent.

[0015]

With the above configuration, the address of the transmission route destination of the received frame registered in the route information is calculated. The presence or absence of the route information in the address conversion table indicated by the calculated address is determined. According to this judgment, when the registration is present, the received frame is transmitted to the transmission route indicated by the route information, and when the registration is not present, the received frame is broadcast, so that the reduction of the communication throughput of the device is prevented. it can.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the control of one embodiment of the inter-LAN connecting device of the present invention.

The inter-LAN connecting device (hereinafter referred to as an adapter) 1 includes a microcomputer 3, a ROM 5, an interface section 9, a buffer 11 and a buffer 13.

The microcomputer 3 controls the entire adapter, and the ROM 5 stores a program for operating the microcomputer 3 at a predetermined address.

The interface unit 7 is connected to the main line LAN and controls transmission with the main line LAN, and the interface unit 9 is tangentially connected to the main line LAN to connect the main line LAN.
And the transmission control with.

The buffer 11 is a route information 21 for registering a transmission route of a received frame, which will be described later, an address for converting a source address (SA) and a destination address (DA) set in the frame into an adapter address. It has a conversion table 17 and a work buffer.

The buffer 13 stores, at a predetermined address, the data of the data portion set in the frames from the trunk LAN 15 received via the interface portion 7 and the branch LANs 17 and 19 received via the interface portion 9. To do.

FIG. 2 is a diagram showing a connection form of a LAN provided with the adapter of the present invention.

Adapters D, E, F, and G are connected to the ring type trunk LAN 15 and branch lines L are connected to the adapter D.
A branch line LAN 19 is connected to the AN 17 and the adapter F. The bus A branch LAN 17 has a terminal A,
B and C are connected, and terminals H, I, J, and K are connected to the bus-type branch line LAN 19.

FIG. 3 is a diagram showing the route information 21 and the address conversion table 23 stored in the buffer 11.

The route information 21 registers the transmission route of the frame received by the adapter D from the terminals A, B and C connected to the branch LAN 17 and the adapters G and E connected to the trunk LAN 15. .. Adapter D
When the frame is received from the terminal A of the branch LAN 17, the main line LA is referred to by referring to the highest address of the route information 21.
The destination address (DA), the source address (SA) and the control unit of the destination adapters E and F and the terminal H of the branch line LAN 19 are added to the received frame to the adapter E of N15, and the frame is transmitted to the trunk LAN 15.

The address translation table 23 translates the source address and the destination address set in the received frame into an adapter address indicating the adapter.

Next, the operation of this embodiment will be described with reference to the flow charts of FIGS.

First, the case of receiving a frame from the branch LANs 17 and 19 will be described with reference to the flowchart of FIG.

The adapter D waits for a frame to be received from the branch line LANs 17 and 19, and when a frame is received from the terminal A of the branch line LAN 17, determines from the route information 21 whether it is a simultaneous broadcast. If it is a simultaneous broadcast, the process proceeds to step 190. If it is not the simultaneous broadcast, the process proceeds to step 120 (steps 100 to 110).

At step 120, the adapter D reads the transmission source part registered in the route information 21 of the issuing source and calculates the address of the address conversion table 23.
The adapter D determines whether or not the calculated address is registered in the address conversion table 23, and if registered, the process proceeds to step 160, and if not registered, the route information and the adapter address are registered (step 120). ~
150).

In step 160, the adapter D reads the destination route of the received frame registered in the route information 21. Further, the adapter D calculates the address of the address conversion table 23 for transmitting the received frame to the trunk LAN 15. The adapter D determines whether or not the calculated address is already registered in the address conversion table 23, and if registered, the process proceeds to step 190, and if not registered, the process proceeds to step 180 (steps 160 to 170).

At step 180, the adapter D reads the adapter address and transmits the received frame to the trunk LAN 15 indicated by the adapter address. on the other hand,
When the process proceeds to step 190, the adapter D detects the trunk LAN 15
The frames received at are transmitted simultaneously.

Next, a case where a frame is received from the trunk LAN 15 will be described with reference to the flowchart of FIG.

The adapter D waits for reception of a frame from the trunk LAN 15, and when receiving a frame from the adapter of the trunk LAN 15, for example, the adapter E, reads the route information 21. The adapter D determines whether the address of the address conversion table 23 read from the route information 21 is already registered in the adapter conversion table 23,
If not registered, the read address is registered in the table 23. On the other hand, if it is registered, the process ends (steps 200 to 240).

As a result, by using the route information 21, the address calculation time of the address conversion table can be shortened and the throughput of data communication can be improved.

[0037]

As described above, according to the present invention, by utilizing the route information, the communication throughput of the device is improved and the calculation of the address of the address conversion table and the waste of the memory capacity are suppressed. The performance of the device can be improved and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing control of an embodiment of an inter-LAN connecting device of the present invention.

FIG. 2 is a diagram showing route information and an adapter conversion table.

FIG. 3 is a diagram showing a connection form of a LAN.

FIG. 4 is a flowchart showing the operation of the present invention.

FIG. 5 is a flowchart showing the operation of the present invention.

FIG. 6 is a flowchart showing a conventional operation.

FIG. 7 is a flowchart showing a conventional operation.

FIG. 8 is a diagram showing a frame format.

[Explanation of symbols]

 1 Adapter 3 Microcomputer 15 Route Information 17 Address Conversion Table 19 Main Line LAN 21, 23 Branch Line LAN A to C, H to K Terminal D to G Adapter

Claims (1)

[Claims] 1. A trunk line LAN, a branch line LAN, and a LAN connection device for transmitting a frame received from the branch line LAN or the trunk line LAN to the branch line LAN or the trunk line LAN, and a frame received from the trunk line LAN or the branch line LAN. Information for registering the transmission route of the, the address calculation means for calculating the address of the transmission route destination of the received frame registered in this route information, and the address indicated by the address calculated by this address calculation means Judgment means for judging the presence / absence of the route information in the conversion table, and transmitting the received frame to the transmission path indicated by the route information when the registration is present by this determination means, and the received frame when the registration is not present. A device for connecting between LANs, characterized in that: