JPH0362647A - Bridge device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention (Industrial Application Field) This invention relates to a bridge device, and particularly to a bridge device that connects networks.

(Prior Art) Generally, frame data as shown in FIG. 2 is used in a bridge device that connects networks using a source routing algorithm.

In the frame data shown in FIG. 2, DA is destination address information, SA is source address information, and RC is a routing RiI indicating the length of routing information.
J information, 5NI-5N3 are ring numbers (RN
I, RN2', RN3) and bridge number (BNI,
BN2. BN3), INFO is text information, and FCS is frame check sequence information.

Routing information SNI to SN3 indicates the transmission route of frame data, and in FIG.
A case is shown in which frame data is transmitted from I to ring RN3 via bridge BN1, ring RN2, and bridge BN2.

Therefore, when each bridge device receives frame data in such a format, it searches for the ring number and bridge number of all the routing information SNI to SN3 in the frame data, and searches for the input ring number, bridge number, and output bridge number. The frame data is passed only if it matches that unique to that bridge device. A specific example of such a frame data selection operation by the bridge device will be explained with reference to FIG.

In FIG. 3, l-1 and 1-2 are stations, 2-
1, 2-2, 2-3 are ring type LAN, 3-
1 and 3-2 are bridge devices. Now, consider the case where the frame data shown in FIG. 2 is transferred from station if having individual address "X" to station 1-2 having individual address "Y". In this case, the destination address DA in the frame data of FIG. 2 becomes "Y" and the source address SA becomes "X'.

Frame data is sent from station l-1 to LAN2-1
When the frame data is transmitted, the bridge device 3-1 receives the frame data and searches for routing information in the frame data. Then, the input ring number RNI of the routing information SNI, and the bridge number BNI
, and the output ring number RN of the routing information SN2
2 corresponds to the bridge device 3-1, the frame data is transferred by the bridge device 3-1 to the LAN 2-2 with the ring number RN2. Next, similar routing information search processing is executed in the bridge device 3-2 as well. Through this search process, the input ring number RN of the routing information 15N2
2, the bridge number BN2, and the output ring number RN3 of the routing information SN3 are confirmed to correspond to the bridge device 3-2, the frame data is transmitted by the bridge device 3-2 to the LAN 2 of the ring number RN3. -3. And L A N
Station 1-2 recognizes that the destination address DA of the frame data transferred to station I-3 is "Y", and station I-2 receives the frame data.

In this way, when a conventional bridge device receives frame data, it searches all the routing information in the frame data and performs a screening process to determine whether or not to pass the frame data. There is. This sorting process temporarily stores the frame data in the buffer memory,
It is executed by examining the data contents in the memory by software processing.

Therefore, a lot of time is spent on the frame data sorting process by the bridge device. Further, since unnecessary frame data must also be stored in the buffer memory for screening processing, the buffer memory usage efficiency is low. Therefore, conventionally, there has been a drawback that the efficiency of data transfer between networks is reduced due to the time required for the sorting process by the bridge device and the low usage efficiency of the buffer memory.

(Problems to be Solved by the Invention) Conventionally, there has been a drawback that the efficiency of data transfer between networks is reduced due to the time required for sorting processing by the bridge device and the low usage efficiency of the buffer memory.

This invention was made in view of these points, and in order to improve the efficiency of data transfer between networks, a bridge device that can perform screening processing in a short time and use buffer memory efficiently. The purpose is to provide

[Structure of the Invention] (Means for Solving the Problems) A bridge device according to the present invention includes a shift register into which frame data from a network is serially input, and a shift register in which the frame data supplied via the shift register is stored. a buffer memory for storing data in the frame data; a comparing means for comparing information sequentially fetched into predetermined data storage positions of the shift register with unique route information assigned to the own bridge device; The frame data is allowed to be stored in the buffer memory when it is detected that route information that matches the route information of the bridge device is included, and the frame data is allowed to be stored in the buffer memory when it is detected that route information that matches the route information of the bridge device is included. and a control means for prohibiting data from being stored in the buffer memory, and is characterized in that the frame data is selected when the frame data is input.

(Function) In this bridge device, when frame data is input, the route information of the frame data is compared with the route information unique to the bridge device, and only when the route information matches, the frame data is stored in the buffer 7 memory. Stored.

In this way, since the frame data sorting process is executed when frame data is input, there is no need to perform the sorting process after storing the frame data in the buffer memory as in the conventional case. In addition, since only necessary frame data is stored in the buffer memory, the buffer usage efficiency can be improved. Therefore, the sorting process in the bridge device can be executed in a short time [11], and the buffer 7
It is possible to improve memory usage efficiency, thereby making it possible to improve data transfer efficiency between networks.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of a bridge device according to an embodiment of the present invention. Here, only a configuration that supports unidirectional data transfer is shown.

In this bridge device, the shift register 20 is for serially inputting frame data received from the LAN to which this bridge device is connected,
It has three data storage areas 20-1, 20-2, and 20-3. The output of this shift register 20 is supplied to a buffer memory 24.

The routing information detection circuit 21 receives frame data and determines the position of the routing information by detecting the beginning of the frame data.
When the input ring number and bridge number of the routing information in the frame data are taken into the data storage areas 20-3 and 20-2 of the shift register 20, respectively, a comparison instruction is output to the coincidence detection circuit 26. Furthermore, the routing information detection circuit 21 detects the timing at which all comparison processing of the routing information ends based on the routing control information RC in the frame data, and notifies the bridge control circuit 28 of the timing.

The register 22 holds a bridge number (for example, BNI) assigned to the own bridge device. Also,
The register 23 holds the input ring number (for example, RNI) assigned to the own bridge device.

The comparison circuit 24-1 compares the information in the data storage area 20-2 of the shift register 20 with the information in the register 22, and its output is supplied to one input of the AND gate 25. Furthermore, the comparison circuit 24-2 compares the information in the data storage area 20-3 of the shift register 20 with the information in the register 2.
3 and its output is supplied to the other input of the AND gate 25. The output of the AND gate 25 is supplied to the coincidence detection circuit 26, and when the comparison circuit 24-1, 24-2 detects a coincidence between the bridge number and the input ring number, a coincidence signal is supplied to the coincidence detection circuit 26. .

When the match detection circuit 26 receives the comparison instruction from the routing information detection circuit 21, it determines whether there is a match signal from the AND gate 25. And AND gate 25
When a match signal is generated from the output ring number holding circuit 27 and the bridge control circuit 28, the output ring number holding circuit 27 and the bridge control circuit 28 are notified that the routing information (bridge number and input ring number) match.

The output ring number holding circuit 27 holds the output ring number when it is taken into the data storage area 20-1 of the shift register 20, and responds to a match notification from the match detection circuit 26. and supplies output ring number information to the buffer memory 29.

The bridge control circuit 28 performs registration control of the bridge number and input ring number of its own bridge device held in registers 22 and 23, write control to the buffer memory 29, and transmission control to the frame sending circuit 30, and performs coincidence detection. When a match notification is supplied from the port 26, the frame data is written in the storage area 29-l of the buffer memory 29, and information on the output ring number corresponding to the frame data is written in the storage area 29-2. On the other hand, when the match notification is not supplied even after the comparison processing of the last routing information is completed, frame data is written to the storage area 29-1 of the buffer memory 29, and output ring number information is written to the storage area 29-2. Writing is not executed. In this case, what is actually prohibited from writing frame data is the text information INFO of that frame data.

The buffer memory 29 includes a storage area 29-L for storing the entire frame data supplied via the shift register 20 and a storage area 29-L for storing the output ring number information held by the output ring number holding circuit 27. −
It has 2. That is, frame data and output ring number information within the frame data are respectively stored in different memory areas.

The frame sending circuit 30 is for sending the frame data stored in the memory area 29-1 of the buffer memory 29 to the LAN to which this bridge device is connected, and the bridge control determines which LAN to send the frame data to. circuit 28
Directed by. That is, the bridge control circuit 28 instructs the frame sending circuit 30 to specify the LAN to which the frame data should be sent based on the output bridge number information stored in the storage area 29-2 of the buffer memory 29.

In a bridge device configured in this way, when frame data is input, the routing information of the frame data (bridge number and input ring number) and the routing information specific to the bridge device (bridge number and input ring number) are When the routing information matches, the frame data is stored in the buffer memory 2.
It is stored in 9. On the other hand, if the routing information does not match, a comparison with the next ring number and bridge number in the frame data is performed sequentially in the same way, and if there is no match even after the comparison of the last routing information is completed, The frame data is discarded and the buffer memory 2
9 is not stored.

In this way, in this bridge device, the frame data selection process is executed when the frame data is input, so there is no need to perform the selection process after storing the frame data in the buffer memory 29 as in the conventional case. Therefore, the sorting process can be performed at high speed using a simple hard-Alan basis. In addition, only necessary frame data is stored in the buffer memory 29, and unnecessary frame data is not stored, so that the usage efficiency of the buffer memory 29 can be improved.

Therefore, the selection process in the bridge device can be executed in a short time, and the efficiency of using the buffer memory 29 can be increased, thereby making it possible to improve the efficiency of data transfer between networks.

Note that although the case where both the input ring number and the bridge number are compared has been explained here, if the arrangement of the bridge device is fixed, it goes without saying that the selection process can be performed by comparing only the bridge numbers. be.

[Effects of the Invention] As described above, according to the present invention, the selection process in the bridge device can be executed in a short time, and the efficiency of use of the buffer memory 29 can be increased, thereby making it possible to transfer data between networks. It becomes possible to improve the transfer efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a bridge device according to an embodiment of the present invention, FIG. 2 is a diagram showing the contents of normal frame data, and FIG. 3 is a diagram showing an example of the configuration of a normal network system. . 20... Shift register, 21... Routing information detection circuit, 22.23... Register, 24-1.2
4-2... Comparison circuit, 25... AND gate, 26
... Coincidence detection circuit, 27 ... Output ring number holding circuit, 28 ... Bridge control circuit, 29 ... Buffer memory, 30 ... Frame data sending circuit.

Claims (1)

Claims: A bridge device that connects networks, comprising: a shift register into which frame data from the network is serially input; a buffer memory which stores the frame data supplied via the shift register; Comparison means for comparing the information sequentially loaded into predetermined data storage positions of the shift register with unique route information assigned to the own bridge device; Allowing the frame data to be stored in the buffer memory when it is detected that matching route information is included, and storing the frame data in the buffer memory when it is detected that matching route information is not included. What is claimed is: 1. A bridge device comprising a control means for prohibiting storage of the frame data, and selecting the frame data when the frame data is input.