JPH05207021A - Frame repeater system - Google Patents

Abstract

PURPOSE:To eliminate useless processing by installing an address table for registering the destination address of a frame not needing to be repeated inside a LAN controller. CONSTITUTION:The reception of the frame addressed to a station 21 transmitted from the station 22 is started by the LAN controller 15 installed inside a frame repeater 1 through a LAN (local area network) 2. At this time, the LAN controller 15 extracts the destination address of the received frame addressed to the station 21, and compares the destination address with the address table 151, and when it finds that the address of the station 21 is registered previously in the address table 151, at this point of time, the LAN controller stops the reception processing of the frame addressed to the station 21. Accordingly, the processing for transferring frame data addressed to the station 21 to a memory device 12 or the repeating processing of the frame addressed to the station 21 by a processor 11 is not performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame relay device which connects a plurality of LANs (local area networks) and relays a frame flowing on each LAN to the other LAN.

[0002]

2. Description of the Related Art In recent years, due to the improvement in the performance of computers, the speed of a LAN connecting the computers has been increasing. At the same time, high throughput is also required for frame relay devices that relay frames between LANs. Figure 4
FIG. 1 is a schematic configuration diagram of a frame relay device according to a conventional technique. The frame relay device 4 has a processor device 41, a memory device 42, a routing database 43, a bus 44, and LAN controllers 45 and 46, and is connected to these. LAN
Frame relay between 5 and 6 is performed.

The processor device 41 performs a frame relay process based on the routing information registered in the routing database 43. The memory device 42 is
The frame data received by the LAN controllers 45 and 46 is stored. In the routing database 43,
The routing information that determines the relay destination of the received frame is registered.

The bus 44 is connected to the processor unit 41, the memory unit 42, the routing database 43 and the LAN controllers 45 and 46, and transfers data. LAN controllers 45 and 46 are connected to LA
The frame transmission / reception control for N5 and N6 and the frame data transfer with the memory device 42 are performed. LAN5 is LA
The N controller 45 is connected to the stations 51 and 52, and LA
It is assumed that N6 is connected to the LAN controller 46 and the station 61.

The operation of the frame relay device 4 configured as described above will be described with a specific example. In the routing database 43, the station 61 has the LA
It is assumed that the routing information that it is connected to N6 is registered. First, when the station 51 transmits a frame addressed to the station 61, the LAN controller 45 inside the frame relay device 4 starts receiving the frame addressed to the station 61 via the LAN 5. At this time, the LAN controller 45 transfers the received frame data addressed to the station 61 to the memory device 42 via the bus 44. And
The processor device 41 has a routing database 43.
Then, the routing information that the station 61 is connected to the LAN 6 is searched for, and the frame for the station 61 is relayed to the LAN 6 based on this routing information. At this time, since the transmission source address of the frame addressed to the station 61 is the station 51 address, the routing information that the station 51 is connected to the LAN 5 is registered in the routing database 43. Finally, the LAN controller 46
Transfers the data of the frame addressed to the station 61 from the memory device 42 via the bus 44 and transmits it to the LAN 6.

Next, when the station 52 transmits a frame addressed to the station 51, the frame addressed to the station 51 passes through the LAN 5 and is connected to the LAN controller 4 inside the frame relay device 4.
Reception is started by 5. At this time, the LAN controller 45 transfers the received frame data addressed to the station 51 to the memory device 42 via the bus 44. Then, the processor device 41 searches the routing database 43 for the routing information that the station 51 is connected to the LAN 5. Based on this routing information, the processor device 41 stops the relay processing of the frame addressed to the station 51, and the station 51 stored in the memory device 42 is stopped.
Discard the data of the addressed frame.

According to the above operation, a frame that does not need to be relayed is not relayed to the other LAN, so that there is an advantage that it is possible to prevent an increase in LAN traffic due to frame relay.

[0008]

However, in the frame relay device having the above-mentioned configuration, even for a frame that does not need to be relayed, the frame data transfer process from the LAN controller to the memory device and the frame data discard by the processor device are performed. However, when a high-speed LAN is connected, there is a problem in that high processing throughput is hindered due to these processing times.

It is an object of the present invention to provide a frame relay device which enables high-throughput frame relay even when a high-speed LAN is connected.

[0010]

In order to solve the above-mentioned problems, the present invention connects a plurality of LANs (local area networks) and connects a frame flowing on the LAN to another L.
A frame relay device for relaying to an AN, which controls transmission and reception of frames with a LAN, a plurality of LAN controllers, a memory device for temporarily storing frame data to be relayed, which is received by each LAN controller, and a station address. And a routing database that holds routing information indicating the correspondence between the LAN and the LAN to which it is connected,
Based on the destination address of the frame data to be relayed, the routing database is referenced to determine the LAN as the relay destination, and the LA to which the LAN is connected.
And a processor device for controlling transfer of the frame data to be relayed from the memory device to the N controller, and the LAN controller has an address table in which addresses of stations under the LAN to which the LAN controller is connected are registered. The destination address of the frame received from the LAN is compared with the address table. If they match, the frame is not received.

Further, if the source address of the frame data to be relayed is not registered in the routing database, the processor device newly registers the address and the LAN corresponding thereto as routing information, and further, The source address is L of the source
If it is not registered in the address table of the AN controller, it may be newly registered.

[0012]

As described above, the LA of the frame relay device has
By providing an address table for registering a destination address of a frame that does not need to be relayed inside the N controller, the LAN controller allows the LAN controller to detect when the destination address of the frame that has started to be received matches the address registered in the address table. , The frame receiving process is stopped. Therefore, the transfer process to the memory device for the frame data that need not be relayed and the frame relay process until the frame data is discarded by the processor device are not performed.

[0013]

1 is a schematic block diagram of a frame relay device for connecting a plurality of LANs and relaying frames between the LANs according to an embodiment of the present invention. 1 is a frame relay device, which includes a processor device 11, a memory device 12,
Routing database 13, bus 14, LAN
LAN2 that has controllers 15 and 16 and is connected to
Frame relay between 3 is performed.

The processor unit 11 performs a frame relay process based on the routing information registered in the routing database 13. The memory device 12 is
The frame data received by the LAN controllers 15 and 16 is stored. In the routing database 13,
The routing information that determines the relay destination of the received frame is registered. This routing information is information indicating which LAN the station is connected to.

The bus 14 is connected to the processor device 11, the memory device 12, the routing database 13, and the LAN controllers 15 and 16 and is used for data transfer inside the frame relay device 1. LAN controller 1
5 and 16 are address tables 151 and 161 respectively.
The transmission / reception control of frames for the connected LANs 2 and 3 and the frame data transfer with the memory device 42 are performed.

In the address tables 151 and 161, destination addresses of frames that are not relayed are registered. Its contents are L connected to the LAN controller to which it belongs.
This is information indicating which station is connected to the AN. LAN2 is a LAN controller 15 and a station 21,
The station 22 is connected, and the LAN 3 is the LAN controller 1
6 and the station 31 are connected.

Regarding the frame relay apparatus configured as described above, the processing flow in each LAN controller at the time of receiving a frame from the LAN shown in FIG. 2 and the registration processing flow at the time of frame relay shown in FIG. The operation will be described. First, the case where the station 22 transmits a frame addressed to the station 21 will be described. Now, in the address table 151, L
It is assumed that the station 21 address and the station 22 address connected to AN2 are registered in advance.

The frame addressed to the station 21 transmitted from the station 22 is started to be received by the LAN controller 15 inside the frame relay apparatus 1 via the LAN 2 (step 1 in FIG. 2). At this time, the LAN controller 15 extracts the destination address of the received frame addressed to the station 21 (step 2), compares the destination address with the address table 151 (step 3), and registers the station 21 address in the address table 151. In this case, the LAN controller 1 is found at this point.
5 stops the reception process of the frame addressed to the station 21 (step 4). Therefore, the process of transferring the frame data addressed to the station 21 to the memory device 12 and the station 2 performed by the processor device 11 are performed.
The relay processing of the frame addressed to 1 is not performed.

As described above, if the destination address of a frame that does not require relay is registered in the address table in advance, it is possible to prevent the frame relay device from performing the receiving process for an arbitrary specific frame. it can. next,
The operation when the station 21 transmits a frame addressed to the station 31 will be described. Now, in the routing database 13, the station 31
It is assumed that the routing information that the is connected to the LAN 3 is registered, and that nothing is registered in the address table 151.

When the station 21 transmits a frame addressed to the station 31,
The reception of the frame addressed to the station 31 is started by the LAN controller 15 inside the frame relay device 1 via the LAN 2 (step 1). At this time, the LAN controller 15 extracts the destination address of the received frame addressed to the station 31 (step 2), compares the destination address with the address table 151 (step 3), and extracts the extracted station 31 address from the address table. Since it is not registered in 151, the frame addressed to the station 31 is received as it is, and the data of the frame addressed to the station 31 is transferred to the memory device 12 via the bus 14 (step 5). Then, the processor unit 11 searches the routing database 13 for the routing information that the station 31 is connected to the LAN 3, and based on this routing information, L
When it is determined that the data is to be transmitted to the AN3, the memory device 12 relays the frame addressed to the station 31 to the LAN controller 16 (step 6 in FIG. 3).

At this time, the processor unit 11 has the station 31
Extract the source address of the destination frame (step 7),
As a result, the routing information (connection information) that the station 21 is connected to the LAN 2 is obtained. Next, the processor device 11 searches the routing database 13 and
It is determined whether or not the obtained routing information has been registered (step 8). Since the routing information that the station 21 is connected to the LAN 2 is not registered yet, it is registered in the routing database 13 (step 9). Further, the address table 151 inside the transmission source LAN controller 15 is searched to determine whether or not the obtained connection information has been registered (step 10), and the connection information indicating that the station 21 is connected to the LAN2. Is not registered, so it is registered in the address table 151 (step 11).

At the same time, the LAN controller 16
Is the station 3 transferred from the memory device 12 via the bus 14.
The data of the frame addressed to 1 is transmitted to the LAN 3. As described above, since the processor device 11 can newly obtain the connection information between the source station and the LAN in the frame relay process, if it is not registered, the processor device 11 registers it in the routing database as the routing information and requires the relay process. It is also registered in the address table as the destination address of the frame not to be processed. In this case, the processor device 11 gives address information to the LAN controller via the bus 14, and based on this, the LAN controller registers in the address table. As a result, the LAN controller does not perform frame reception processing that does not require relay, and can respond to changes in the connection status of stations.

In the present invention, when the address information is registered in the address table during the relay processing,
The processor device 11 may directly register the address information in the address table without passing through the bus 14, and in this case, the processing time for updating the address information becomes short.

[0024]

As described above, according to the present invention, by providing an address table for registering a destination address of a frame that does not need to be relayed inside a LAN controller included in a frame relay device, it is possible to handle frame data that does not need to be relayed. Therefore, the transfer processing to the memory device and the frame relay processing until the frame data is discarded by the processor device are not performed, and there is an effect that wasteful processing is eliminated. As a result, there is an effect that the processing for receiving a frame that requires relay can be performed in the idle time, and high throughput can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a frame relay device according to an embodiment of the present invention.

FIG. 2 is a processing flow in each LAN controller at the time of receiving a frame from a LAN in the embodiment.

FIG. 3 is a registration processing flow at the time of frame relay in the embodiment.

FIG. 4 is a schematic configuration diagram of a frame relay device in the related art.

[Explanation of symbols]

 1 Frame Relay Device 11 Processor Device 12 Memory Device 13 Routing Database 14 Bus 15, 16 LAN Controller 151, 161 Address Table 2, 3 LAN (Local Area Network) 21, 22, 31 Stations

Claims (2)

[Claims] 1. A plurality of LANs (local area networks) are connected to each other, and a frame flowing on the LAN is connected to another LA.
A frame relay device for relaying to N, and a plurality of LANs for controlling transmission / reception of frames to / from LAN
A controller, a memory device for temporarily storing frame data to be relayed by each of the LAN controllers, a routing database for holding routing information indicating correspondence between an address of a station and a LAN to which the station is connected, and the relay The LAN to be the relay destination is determined by referring to the routing database based on the destination address of the frame data to be transmitted, and the LA to which the LAN is connected
And a processor device for controlling transfer of the frame data to be relayed from the memory device to the N controller, wherein the LAN controller is connected to the LA device.
It is characterized by having an address table in which the addresses of stations under N are registered, comparing the destination address of the frame received from the LAN with the address table, and not receiving the frame if they match. Frame relay device. 2. The processor device, if the source address of the frame data to be relayed is not registered in the routing database, newly registers the address and the LAN corresponding thereto as routing information, The frame relay device according to claim 1, wherein if the source address is not registered in the address table of the LAN controller that is the source, the source address is newly registered.