JPH0983576A - Inter-network connection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve data transmission efficiency by processing a frame identified to be that of multiple address communication with a route different from a repeating processing means. SOLUTION: An inter-LAN connection device is provided with LAN/F 51a to 51n receiving the frames transmitted between the LANs and extracting address information DA, route control parts 52a to 52n identifying whether the frame is that of multicasting communication or that of individual communication based on address information DA extracted by LANI/F 51a to 51n, outputting the frame of multicasting communication to a multicasting frame buffer 56 and outputting the frame of individual communication to a switch 53, a simultaneous multiple address processing part 55 transmitting the frame stored in the multicasting frame buffer 56 to LANI/F 59a to 59n corresponding to the destination, the multicasting buffers 57a to 57n and multicasting control part 58a to 58n.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a LAN and a W, for example.
The present invention relates to an inter-network connection device that connects networks such as AN.

[0002]

2. Description of the Related Art Conventionally, data transmitted between networks, for example between LANs, is relayed on a frame-by-frame basis by a LAN-to-LAN connecting device such as a bridge and a network concentrator (HUB: hub). The transmission efficiency may decrease depending on the load concentration or the destination of the frame. At this time, improvement is desired so as not to drop the transmission efficiency.

The conventional inter-network connecting device is as follows.

(A) Repeater This is a device that is mainly used when connections are made over a physical transmission path distance limitation and that only amplifies signals such as electricity and light.

When the number of terminal devices connected to the network increases, the load on the network increases in proportion to the increase in the number of terminal devices. Therefore, there is a drawback that the transmission speed can be obtained at a considerably low level with respect to the transmission speed of the network. This includes transmission line sharing type network concentrators (hereinafter referred to as hubs) and concentrators.

(B) Bridge This is to eliminate the drawbacks of the repeater described above. From the destination address of the received frame, the frame within the own network is discarded and only the one for the other network is transferred. It is a device. In the case of this bridge, since the routing process is not performed, it is impossible to determine the broadcast in the own network recognized by the upper layer protocol, so that it is practically impossible to filter all unnecessary frames. For this reason, in a large-scale network system, it becomes impossible to secure a band commensurate with the transmission speed like a repeater.

(C) Router This is a device for solving the drawbacks of the repeater and the bridge, and is a device for translating a higher-level routing protocol and transferring only one destined for another network. If the number of terminals connected to one network is reduced, the bandwidth can be improved with respect to other devices. However, in a large-scale network system, the number of divided networks becomes enormous, and the number of own ports is also enormous. The routing process is normally executed by the software provided by the processor provided inside the router. Therefore, if this routing process is slow, it becomes a bottleneck in the network system. Therefore, it is necessary to have a processor (hardware) capable of high-speed processing corresponding to the communication speed of the network, which is more expensive than other devices. Can be said.

(D) Switching Hub Functionally, it is the same as the above-mentioned bridge, but in the bridge, the connection between network interfaces is realized by a single transmission path, whereas in the bridge, switching is performed between the interfaces. Since it is connected by, it has a plurality of transmission lines.

Generally, in the case of a bridge, when the number of network interfaces increases, the transfer capacity in the bridge will be limited, but the switching hub does not have such a limit. The conventional switching hub will be described below.

As shown in FIG. 11, a conventional switching hub includes a frame switch having a plurality of input ports IN-1 to IN-n and a plurality of output ports OUT-1 to OUT-n, and a control system (not shown). (A route controller and a switch controller, etc.) are provided.

In the case of this switching hub, when a frame is input to the plurality of input ports IN-1 to IN-n,
Based on the destination information, the switch control unit controls the frame switch to switch the internal line connection, connect to the output ports OUT-1 to OUT-n corresponding to each destination, and transfer the frame to each destination. ing.

By the way, in recent years, the number of terminals connected to each LAN is increasing, and it is necessary to increase the relay processing speed of the switching hub in proportion thereto.

Therefore, in order to maximize the performance of the switching hub, it is possible to use a high-speed bus inside the hub.

However, this type of bus is more expensive as it operates at a higher speed, and affects the cost of the entire apparatus. Therefore, there is a problem that a higher speed bus cannot be used inside the hub.

Even if frames are sequentially input from the LANs to the input ports of the switching hub, the destinations are often concentrated in one place (one output port) in practice.

In this case, frames other than the frame initially input to the input port are discarded. To solve this problem, a technique has been proposed in which a frame buffer for waiting the processing order is provided in each input port. In this case, a frame buffer with a large storage capacity is used in accordance with the amount of frames (length) waiting for processing and the number of input ports. Since it is necessary to provide a plurality of frames and input frames are not discarded, there is a problem that the cost becomes very high.

Generally, as one of communication functions on a network, for example, simultaneous broadcast (multicast) communication and broadcast (simultaneous) communication are well known.

The multicast communication function is a very convenient function because when one multicast frame is sent to the inter-network connecting device, the frame can be transmitted to all LANs to which the inter-network connecting device is connected.

However, in the inter-network connecting device, the switching hub has a one-to-one port connection due to the structure of the internal frame switch, so that when performing simultaneous broadcast communication or simultaneous communication, each input / output Similar to the above, a frame buffer is prepared for each port, and a complicated switch control is required in which switching control of the frame switch is performed for each destination and each frame is output from the frame buffer. During that time, there is a problem in that the frame transmission of normal individual communication is excluded, and the data transmission efficiency of the entire device decreases.

On the other hand, the multicast communication also has a disadvantage for the LAN.

That is, in the multicast communication, the frames are simultaneously transmitted from the switching hub to all LANs, but there is also a problem that the transmission capacity is wasted for LANs that do not require the multicast frames and other communication is hindered. is there.

Therefore, in the case where the switching hub is provided with a function (grouping function) that performs grouping processing between a plurality of LANs in advance for transmission of all frames and disables frame communication between different groups. There are many.

This grouping function is preliminarily set in one database by a network administrator for each LAN-to-LAN connecting device, and is provided for each input port each time a frame from the network is input to each input port. The route controller is a function for searching and executing the database.

However, this kind of database is often complicated in access control, and when the database is accessed from each route control unit for all the frames input to each input port, especially in the case of a multicast frame, etc. However, since the search process takes a lot of time, access to the database may be overloaded and the process may be stalled.

The same thing can be said that the processing is stagnant not only in the above database but also in the route information database when each route control unit searches for route information.

In this case, each route control unit searches the route information database from the destination information of each frame input to each input port and determines the frame transfer route.

Therefore, since the access to the route information database is always performed for each frame, the processing delay cannot be avoided, and as a result, the frame transmission efficiency is lowered.

[0028]

As described above, in the above-mentioned conventional inter-network connection device, a broadcast frame and a simultaneous communication frame are input together with an individual communication frame, and a database is accessed for each frame. Then, there is a problem in that the frame transmission efficiency is reduced due to the bus performance, cost, and access status to the database.

The present invention has been made in order to solve such a problem, and while data of various communication contents are received, data transmission can be performed without lowering the data transmission efficiency. As a result, An object of the present invention is to provide an inter-network connection device capable of improving data transmission efficiency.

[0030]

In order to achieve the above object, the inter-network connecting device according to claim 1 is provided between the networks and is a frame including destination information transmitted between each other. In the inter-network connecting device for relaying the packet, the receiving means for receiving the frame transmitted between the networks, the destination extracting means for extracting the destination information from the frame received by the receiving means, and the destination extracting means. Identification means for identifying whether the frame is for simultaneous broadcast communication or individual communication based on the extracted destination information, and a frame for which the identification means identifies the broadcast communication 1
Second relay processing means for performing relay processing through a route different from the relay processing means of.

The inter-network connecting device according to a second aspect of the present invention is an inter-network connecting device that is provided between networks and relays a frame including destination information transmitted between the inter-network connecting devices. Receiving means for receiving the frame to be transmitted, destination extracting means for extracting destination information from the frame received by the receiving means, and individual communication of the frame based on the destination information extracted by the destination extracting means For identifying whether the individual communication frame or the broadcast communication, a plurality of input ports to which the individual communication frame is input, and a frame for transmitting the frames input to these input ports to a desired destination A switch having a plurality of output ports and controlling the switch, corresponding to an input port to which the frame is input and a destination Switch control means for connecting to the output port, broadcast broadcast processing means for performing relay processing for transmitting the broadcast broadcast frame to a plurality of desired destinations, and for individual communication by the identifying means. And a path control unit for outputting the identified frame to the switch and outputting the frame identified as for the broadcast communication to the broadcast processing unit.

According to a third aspect of the present invention, there is provided the inter-network connecting apparatus according to the second aspect, wherein the simultaneous broadcast processing means indicates transfer permission / prohibition between a source and a destination on the network. A grouping database in which transfer control information is accumulated, and a frame identified by the identifying means as one for the broadcast communication,
The broadcast processing unit includes a broadcast processing unit that refers to the grouping database and relays only the transfer destinations.

The inter-network connecting device according to the fourth aspect is an inter-network connecting device which is provided so as to be interposed between the networks and relays a frame including destination information transmitted between the networks. A receiving unit for receiving the frame to be transmitted, a destination extracting unit for extracting the destination information from the frame received by the receiving unit, and the frames are simultaneously broadcast based on the destination information extracted by the destination extracting unit. Identification means for identifying whether it is for broadcast communication or individual communication, a first bus for relaying the frame for individual communication, a second bus for relaying the frame for simultaneous broadcast communication, and the identification The frame received by the receiving means according to the communication content identified by the means is divided into the first bus or the second bus and is sent to each destination. It is provided with a transfer control means for feeding.

Furthermore, the inter-network connecting device according to the fifth aspect is an inter-network connecting device which is provided between the networks and relays a frame including destination information transmitted between the networks. Route information storage means for storing route information for a plurality of destinations, receiving means for sequentially receiving frames transmitted between the networks, and destination extracting means for extracting destination information from the frames received by the receiving means. And a destination information storage unit that stores the destination information extracted by the destination extraction unit and a route information storage unit based on the destination information stored in the destination information storage unit, and sets a corresponding route to set the frame. A first relay processing means for relay processing the destination frame and the destination extracting means when the next frame is received by the receiving means. And already comparing means for comparing the destination information stored in the extracted the next destination information the destination information storage means, the comparison result by the comparison means,
When the mutual destination information is matched, the second relay processing means is provided for relaying the frame through the route already set corresponding to the destination.

According to a sixth aspect of the present invention, there is provided an inter-network connecting apparatus according to the fifth aspect, wherein when the result of the comparison by the comparing means indicates that the destination information does not match each other, It further comprises update means for updating the stored content to that of the next frame.

[0036]

According to the first aspect of the present invention, when selecting a route for transmitting a received frame to a destination, whether the frame is for individual communication or is broadcast based on the destination information of the received frame. It is identified.

As a result of this identification, if the frame is for individual communication, it is relayed by the first relay processing means. If the frame is for simultaneous broadcast, the frame is relayed by the second relay processing means via a route different from that of the first relay processing means. Therefore, frame processing is differentiated, and the load on each relay processing unit can be reduced.

In the case of the second aspect of the present invention, when the received frame is for broadcast communication, it is not input to the switch but is sent to the broadcast processing means, where a desired plurality of frames are transmitted. It is transmitted to the destination. Therefore, only the multicast frame needs to be processed by the simultaneous broadcast processing means, and only the individual communication frame needs to be processed by the switch, so that it is possible to use a relatively low speed hardware for executing each function. In the case of the third aspect of the invention, the broadcast processing unit provided independently of the switch accesses the grouping database only for the multicast frames to collectively perform the grouping process.

Therefore, it is not necessary to access the database each time the plurality of route selection units receive data, and the number of access to the database is reduced.
Waiting for access is reduced.

In the case of the invention described in claim 4, the frame for individual communication is relayed by the first bus. Further, the frame of the simultaneous broadcast communication is relayed by the second bus.

That is, the relay processing route is differentiated between the individual communication frame and the broadcast communication frame, and a relatively low speed bus can be used for each.

In the case of the fifth and sixth aspects of the present invention, the destination information stored first in the destination information storage means and the destination information of the next received frame are compared by the comparison means, and the destination information matches each other. In this case, the frame is relayed by the route already set corresponding to the destination. Further, as a result of the comparison by the comparison means, if the destination information does not match each other, the stored contents of the destination information storage means are updated to those of the next frame. Therefore, only when the frame destinations are the same, data can be transmitted to a desired destination without accessing the route information database.

As described above, the data transmission efficiency can be improved while reducing the device cost.

[0044]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a connection structure of an inter-LAN connecting device of a first embodiment according to the inter-network connecting device of the present invention.

In FIG. 1, reference numeral 1 denotes an inter-LAN connecting device, which is connected to a plurality of networks 2a to 2n, a plurality of client machines 3a to 3n, and server machines 4a to 4n. A plurality of terminals (not shown) are connected to each of the networks 2a to 2n, and between terminals and machines connected to a LAN (local area network) and a WAN (wide area network). Various communication can be performed through the LAN connection device 1.

As shown in FIG. 2, a frame, which is one unit of data transmitted between networks, has at least a destination address (Destination Addres) DA, a source address (Source Addres) SA, and data DATA. There is. The check data may be added to the end of the data DATA.

As shown in FIG. 3, the inter-LAN connecting device 1
Is the LA for sending and receiving data that is transmitted between networks.
NI / F 10a to LAN I / F 10n, route information database 11, database control 12, interconnection circuit 1
3, route control units 14a to 14n, and the like. The LAN I / F 10a to LAN I / F 10n are for extracting a frame from data (signal) received from each network or each machine, or assembling the frame as data and transmitting it to each network or each machine. . The route information database 11 is a memory that stores (accumulates) a connection port number for each terminal address.
The database control 12 arbitrates (controls) access to the route information database 11 from the route control units 14a to 14n of each port. The interconnection circuit 13 is a switch and an input / output port (buffer).
And each of the path control units 14A to 14n.
The switch controls the switch to connect the input port and the output port to each other, and the data is transmitted to the output side through the connection path. Each of the route control units 14a to 14n extracts the destination information from the frame received from the LAN I / F 10a to 10n connected to the route control unit 14a to 14n, accesses the route information database 11, reads the port number of the destination, and the interconnection circuit. 13 to control the input port and the output port to the destination. The above-mentioned units are connected by a data bus and a control bus. As shown in FIG. 4, each of the route control units 14a to 14n, for example, the route control unit 14a, has a destination address register (DA RE
G) 141 and 142, comparator 143, database address control unit (DB address operation unit) 144, database access control unit (DB access control unit) 145 port number register (PORT number REG) 146, switch control unit 147, etc. Has been done.

The destination port number of the previous frame is stored in the PORT number REG146. The switch control unit 147 determines whether the PORT number REG 146 or the DB depending on the comparison result by the comparator 143.
The destination port number is obtained from one of the access control units 145 to control the interconnection circuit 13, that is, the switch.

In the case of the LAN-to-LAN connecting device 1, a certain LA
The data (signal) transmitted from N is, for example, LAN I /
When received by the F 10a, the LAN I / F 10a extracts a frame from the received data and routes the frame through the reception data line (data bus) to the path controller 14
Output to a.

The path control unit 14a decodes the input frame and extracts the destination address DA from the destination field.
Is extracted, and in the case of the first data, DA REG14
1 in that order.

Then, the DB address operation unit 144 determines that D
A predetermined operation for obtaining an address on the memory is performed from the contents of the AREG 141 to generate an address in the route information database 11 where the corresponding route information is stored, and the DB access control unit 145 is notified. In response to this, the DB access control unit 145 accesses the route information database 11 to obtain the port number of the connection destination.

On the other hand, in the comparator 143, DA REG1
41 and the destination address of the DA REG 142 are compared, and the comparison result is notified to the DA REG 141, the DB access control unit 145, and the switch control unit 147. For the first frame, DA REG
Since nothing is held in 142, this comparator 14
The comparison result of 3 does not match.

D receiving the comparison result from the comparator 143
A REG141, when the comparison result does not match,
The latest destination address stored in itself is DA RE
It is copied to G142 as it is, and the contents held in DA REG 142 are updated.

If the two addresses differ, the DB access control unit 145 that receives the comparison result from the comparator 143 accesses the destination information database 11 connected to the outside of the route control unit 14a, and If so, the destination information database 11 is not accessed.

Further, when the comparison result is not the same, the switch control unit 147 which receives the comparison result performs the switch control with the access result of the DB access control unit 145, and when the comparison result is the same, the PORT number R
Switch control is performed with the contents of EG146. Therefore, in the case of the first frame, the switch control unit 147
Performs switch control of the interconnection circuit 13 based on the access result of the destination information database 11. Finally, the result of accessing the database by the DB access control unit 145 is written in the PORT number REG146.

On the other hand, when the data is decoded and the destination address of the next frame is input and held in DA REG 141, the next destination address currently held in DA REG 141 and DA REG 142 by the comparator 143.
It is compared with the destination address of the previous received frame already held in.

Here, when successive frames have the same destination, the address comparison results by the comparator 143 match.

Then, in this case, the switch controller 147
Controls the interconnection circuit 13 with the contents of the PORT number REG146.

As described above, according to the LAN-to-LAN connecting device of the first embodiment, when the result of analyzing the data shows that the consecutive frames have the same destination address, each route control unit 14
Since a to 14n perform switch control of the interconnection circuit 13 with the contents of the PORT number REG146 inside the a to 14n, they do not access the destination information database 11 connected to the outside of the a to 14n. In the LAN-to-LAN connecting device having 14a to 14n, the larger the amount of data to be sent to the same destination, the smaller the number of accesses to the destination information database 11 and the more efficient route control.

As a result, the throughput between input and output, that is, the data transmission efficiency can be improved.

Next, referring to FIG. 5, the LAN of the second embodiment.
The inter-connection device will be described.

FIG. 5 is a diagram showing the essential structure of the LAN connecting device of the second embodiment.

As shown in the figure, this LAN-to-LAN connecting device is a LAN for receiving data transmitted between networks.
I / F 51a to LAN I / F 51n, path control units 52a to 52
n, input buffers IN-1 to IN-n, output buffer O
UT-1 to OUT-n, switch 53, switch control unit 54, broadcast processing unit 55, multicast frame buffer 56, multicast buffers 57a to 57n,
The multicast control units 58a to 58n and LAN I / F 59a to LAN I / F 59n for data transmission are included.

LAN I / F 51a to LAN I / F 51n are LA
A signal transmitted between N is received, and a frame is extracted from the received signal. Path control units 52a to 52
n determines the port to which the terminal indicated by the destination is connected from the destination field of the frame extracted by each LAN I / F 51a to LAN I / F 51n. The input buffers IN-1 to IN-n and the output buffers OUT-1 to OUT-n are buffers for inputting / outputting data to / from the switch 53. The switch 53 includes input buffers IN-1 to IN-n and output buffers OUT-1 to O.
UT-n is a crosspoint switch that connects one-to-one with UT-n according to the destination. The switch control unit 54 uses the control information from each of the route control units 52a to 52n to switch the switch 5
3 for connection control. Broadcast processing unit 55
At the request of the route control units 52a to 52n, the received frame is written in the multicast frame buffer 56, and the plurality of multicast buffers 57a to 57a on the transmission side are transmitted.
The control for transferring the frame to 57n is performed. Multicast control units 58a to 58n
Checks the data output from the switch 53,
If the data was a multicast control code,
Multicast buffers 57a-5 for transmitting frames
It is read from 7n and transferred to the LAN I / F 59a to 59n for transmission.

The structure of the frame is the same as that shown in FIG.

Next, the operation of this LAN-to-LAN connecting device will be described.

In the case of this LAN-to-LAN connecting device, a certain LAN
To LAN I / F 51a to 51n, such as LA
When the data (signal) is received by the NI / F 51a or the like, the data is divided into frames by the LAN I / F 51a, the destination address DA is extracted in frame units, and the route is based on the destination address DA. A route is selected by the control unit 52a.

At this time, the route control unit 52a first confirms the contents transmitted to the destination. Destination address DA
Is usually composed of a bit string (code) consisting of multiple bits. One frame is transmitted to each destination, or 1 is used for multicast or broadcast.
Whether to transmit one frame to multiple destinations at once is determined from the bit arrangement. For example, if the bit string is a sequence of "1", it is determined to be multicast communication.

When the result of the confirmation of the destination address is, for example, the content of the frame transmission by the multicast (broadcast) communication, the arrival order of the frames is input from the LAN I / F 51a to the corresponding input buffer IN-1 of the switch 53. A control code with a short data length is output instead of the multicast frame so as not to change. Also, the frame itself is
It is sent to the multicast frame buffer 56 through the broadcast processing unit 55 instead of the switch 53 and is temporarily stored therein.

Then, the broadcast processing unit 56 reads out the multicast frame stored in the multicast frame buffer 56 and outputs it to the respective multicast buffers 57a to 57n to each LAN I / F to LAN I / F to output the multicast frame. Are stored in each multicast buffer.

On the other hand, each multicast control unit 5
8a to 58n are connected to the output buffer O through the switch 53.
The data output from the UT-1 is monitored, and when the data is a control code, the multicast frame is read from each of the multicast buffers 57a to 57n and is sent to each LAN I / F to LAN I / F 59a to 59n. Output. In each LAN I / F to LAN I / F 59a to 59n, the input frame is assembled into data and the LAN of each destination is assembled.
Send the data (signal) to the navel.

As described above, according to the LAN-to-LAN connecting apparatus of the second embodiment, when the received data is a multicast frame, the multicast frame is not sent through the switch 53 but through the broadcast processing unit 55. Since it is temporarily stored in the buffer 56, and is simultaneously broadcasted through a route different from individual communication and output to each destination, it is not necessary to allocate all frames by the switch 53 as in the conventional case. That is, the load on each processing unit such as the switch 53 and the broadcast processing unit 55 is reduced by the amount of the processing divided according to the content of the frame, and low-speed hardware can be used for each unit.

Further, since the multicast frame is not processed by the switch 53, it is not necessary to provide a large-capacity transmission / reception frame buffer for each input / output port of the switch 53 in consideration of the processing waiting frame as in the conventional case. As a result, the frame transmission efficiency can be improved, and all the switches need to be designed in consideration of only individual transfer, and the switch circuit can be simplified.

Also, what is inputted to the switch is a control code of the multicast frame, which is sufficiently small with respect to the frame length, so that the input / output buffer provided inside / outside the switch can be made small. Further, since the switch 53 is dedicated to individual communication, the switch control time for that purpose can be reduced and the efficiency of use of the switch can be improved. Further, since the processing waiting time is reduced, the multicast frame is not discarded along with other frames.

Next, referring to FIG. 6, the LAN of the third embodiment
The inter-connection device will be described.

FIG. 6 is a diagram showing the configuration of the LAN-to-LAN connecting device of the third embodiment. In the third embodiment, the same components as those in the second embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, the multicast grouping database 60 has a LAN I / F which receives data.
Grouping information indicating prohibition / permission of LAN I / F (output port) on the output side for (input port) is stored. The simultaneous broadcast processing unit 55 includes route control units 52a to 52.
In response to the request of n, the received frame is written to the multicast frame buffer 56, and the output port side permitted based on the grouping information obtained by accessing the multicast grouping database 60, that is, any of the multicast buffers 57a / 57n. Control to transfer the frame to or from. The multicast control units 58a to 58n check the data output from the switch 53 through the output buffers OUT-1 to OUT-n. If the data is a control code indicating multicast, the corresponding frame data is sent to each multicast buffer. The data is read from any of 57a to 57n and transferred to the LAN I / F 59a to 59n. If no data exists in each of the multicast buffers 57a to 57n, no multicast frame is sent to that port.

Next, the operation of this LAN-to-LAN connecting device will be described.

In the case of this LAN-to-LAN connecting device, a certain LAN
When the frame from is input to any of the LAN I / Fs 51a to 51a, the communication contents of the frame are checked by the route control units 52a to 52n. Then, if the communication content of the received frame is individual communication, the received frame is input buffer IN-1 to INn to the switch 53.
Sent to

If the communication content of the received frame is a multicast communication frame, only the control code for the frame is the input buffer IN-1 to the switch 53.
~ INn, the frame itself is sent to the multicast frame buffer 56 through the broadcast processing unit 55.
Sent to and temporarily stored.

The broadcast processing section 55 accesses the multicast grouping database 60 based on the destination information of the frame and searches for grouping information.

Then, the prohibition / permission of the input port / output port is judged based on the grouping information obtained from the multicast grouping database 60, and the output port permitted by the grouping information, that is, the number of the plurality of multicast buffers 57a to 57n. Then, the frame of the multicast frame buffer 56 is transferred.

On the other hand, when the multicast control units 58a to 58n check the data output from the switch 53 and the control code indicating the multicast frame is output, the multicast control unit 5
8a to 58n check whether or not frame data exists in each of the multicast buffers 57a to 57n that it is responsible for.

Then, each multicast control unit 5
8a to 58n read the frame data only from the frame data that existed, and the LAN I / F to LAN I / F 59
a to 59n.

That is, similar to the second embodiment, the relay processing is performed by different processing units according to the communication contents of the received frames, and particularly for multicast frames, the grouping processing is collectively performed by the simultaneous broadcast processing unit 55. Is done.

As described above, according to the LAN-to-LAN connecting apparatus of the third embodiment, the individual communication frame is sent to the switch 53 as usual and relayed to the output port corresponding to the destination, while the multicast frame is Since the simultaneous broadcast processing unit 55 accesses the multicast grouping database 60 to collectively perform the grouping process, compared with the conventional case where each route control unit 52a to 52n accesses the database for all received frames. , The number of access to the database can be reduced.

Further, the switch control unit 54 may control the switching of the switch 53 only for the individual communication frame, and the broadcast processing unit 55 can freely obtain the grouping information and the multicast grouping database 60 without considering the other. You can do it by accessing. As a result, a relatively low-speed processor can be used as the processor that executes the functions of the above-mentioned units.

As a result, the frame transmission efficiency can be improved, and the LAN connecting device can be realized at low cost by using the low speed internal bus and the low speed hardware (processor). Next, with reference to FIGS. 7 and 8, an inter-LAN connecting device of the fourth embodiment will be described. FIG. 7 shows L of the fourth embodiment.
FIG. 8 is a diagram showing the configuration of the inter-AN connection device, and FIG. 8 is a diagram showing the internal configuration of the inter-network connection unit of the LAN inter-connection device of FIG.

In FIG. 7, reference numeral 70 denotes an inter-LAN connecting device, which is connected to a plurality of networks 71a to 71c. The inter-LAN connecting device 70 includes inter-network connecting units 73a to 73c, which are connected to the networks 71a to 71c via network interfaces (network I / F) 72a to 72c, and an individual transfer control unit 7.
4, multicast transfer control unit 75, individual transfer control unit 7
4 and an internal bus dedicated to individual transfer (individual transfer dedicated bus) 7 connected to the inter-network connection units 73a to 73c.
6. Consists of an internal bus (multicast transfer exclusive bus) 77 or the like which is connected to the multicast transfer control unit 75 and the inter-network connecting units 73a to 73c and is provided independently of the individual connection exclusive bus 76 and dedicated to multicast transfer Has been done.

The terminals A and B are connected to the network 71a, the terminal C is connected to the network 71b, and the terminal D is connected to the network 71c. The network I / Fs 72a to 72c are interfaces of an existing LAN (local area network), and are CSM.
It is of the A / CD system.

As shown in FIG. 8, the inter-network connecting units 73a to 73c are a transmitting unit 81, a receiving unit 82 for connecting the networks 71a to 71c and the respective network I / Fs 72a to 72c, and frame data after filtering. A frame buffer 83 for temporarily storing the address, an address registration unit 84 in which a plurality of addresses are registered in advance, a destination address of a frame transmitted / received by the network I / Fs 72a to 72c, an internal bus interface (not shown), etc. And an address comparison unit 85 for comparing frames with each other, a transmission control unit 86 for performing control for transmitting a frame to a destination network, a multicast control unit 87 for performing control for transferring only multicast frames through the multicast transfer exclusive bus 77, and the like. Has been done.

The operation of the inter-LAN connecting device 70 will be described below.

First, the filtering operation of the inter-LAN connecting device 70 will be described.

In FIG. 1, when terminals in the own network communicate with each other, for example, when data is transferred from terminal B to terminal A, the data from terminal B is the network of terminal A and LAN connection device 70. It is received by the inter-connection unit 72a. Since the data received by the terminal A is from the terminal B in the same segment, it is received as it is.
Further, the inter-network connection unit 7 of the inter-LAN connection device 70
The data received by 2a is decomposed for each frame and the destination address is extracted. This address is compared with the registered address by the address comparison unit 85. As a result of the comparison, since it matches the internal one, it is discarded so as not to be sent to the outside.

On the other hand, when the frame addressed to the terminal C of the other network 71b is received by the inter-network connection unit 73a through the internal bus, for example, the multicast transfer exclusive bus 77, it is not the terminal address in the own network. Is not registered, the frame addressed to the terminal C is discarded.

Next, the data transmission operation of the LAN-to-LAN connecting device 70 will be described.

For example, when the network I / F 72a receives data from within its own network, the data is decomposed in frame units and its destination address is extracted. Then, the address comparison unit 85 copies the destination address and compares it with the address registered in the address registration unit 84.

If the destination addresses match as a result of comparison, the data transmission is within the own network. In this case, the address comparison unit 85 outputs a non-write signal (control signal) to the frame buffer 83, The frame is not written to the frame buffer 83.

If the destination addresses do not match, the data is transferred from the local network to the outside. In this case, the frame buffer 83 from the address comparison unit 85 is sent.
A write signal (control signal) is output to the multicast controller 87 and the frame is transferred to the frame buffer 83.
Is written to.

Upon receiving the write signal, the multicast control section 87 confirms whether or not the multicast transfer is based on the destination address of the received frame.

If the individual transfer is not the multicast transfer, the received frame written in the frame buffer 83 is read out from the frame buffer 83, and the control signal is transferred individually using the individual transfer exclusive bus 76. Output to the control unit 74. The individual transfer control unit 74 receives the control signal and receives the individual transfer exclusive bus 76.
To output the data through.

If the result of the confirmation is that the transfer is multicast transfer, the multicast control section 87 outputs a control signal to use the exclusive multicast transfer bus 77. Therefore, the frame is transferred to a desired destination through the multicast transfer exclusive bus 77 of the two internal buses under the control of the multicast transfer control unit 75.

As described above, according to the LAN-to-LAN connecting apparatus of the fourth embodiment, by providing the two internal buses (individual transfer exclusive bus 76 and multicast transfer exclusive bus 77) as internal buses in the apparatus, multicast Since a frame such as a frame which requires a heavy load for the relay process can be relayed through a route different from that of the individual transfer frame, it is possible to improve the data transfer efficiency in the inter-LAN connecting device 70.

As a result, the data transmission efficiency of the entire inter-network communication can be improved.

By applying the present invention to a computer network system having a relatively large scale, it can be said that the effect is increased. In addition to the fourth embodiment, the present invention can be applied to various final line type communication devices.

Next, the inter-LAN connecting device of the fifth embodiment will be described with reference to FIGS. FIG. 9 is the fifth
FIG. 10 is a diagram showing a network configuration in which the LAN inter-connection device of the embodiment is used, and FIG. 10 is a diagram showing an internal configuration of the inter-network connection unit of the LAN inter-connection device of FIG.

As shown in FIG. 9, the LA of the fifth embodiment is
As the N-to-N connecting device, a plurality of LAN-to-LAN connecting devices of the above-described fourth embodiment are installed. In this case, two LA connecting devices are installed.
Internal buses 76 and 77 from the N connection devices 70a and 70b
Is connected to the bus switches 91 and 92 outside the device, and the bus arbiters 93 and 94 attached to the bus switches 91 and 92 are connected.
Is configured to control the bus switches 91 and 92 to acquire the bus right.

As shown in FIG. 10, each bus arbiter 9
3 and 94, an arbitration function unit 95 that performs arbitration (arbitration) for each internal bus (individual transfer exclusive bus 76, multicast transfer exclusive bus 77), and a switch buffer for bus switch to the internal bus 96. 97a and 97b are provided.

With such a configuration, the LAN connection device 7
When data is transferred between 0a and 70b, the data from the inter-network connecting devices 70a and 70b are temporarily stored in the switch buffers 97a and 97b corresponding to the bus switches 91 and 92 through the internal bus 97.
After the arbitration function unit 95 performs an arbitration operation for bus priority acquisition based on each frame information and performs priority control, the bus switches 91, 9
2 controls switching of buses for transmitting data. According to the LAN-to-LAN connecting device of the fifth embodiment, the internal buses 76 and 77 of the two systems are switched and controlled by the existing bus switches 91 and 92 provided outside the device to transmit to the internal buses 76 and 77. It is possible to control the priority of the data to be stored.

[0111]

As described above, according to the present invention, it is discriminated whether the frame is for individual communication or broadcast communication based on the destination information of the received frame, and it is different depending on each frame. Since the relay processing is performed along the route, the load on each relay processing unit can be reduced.

Further, since the grouping process for the destination is carried out only for the frame of the simultaneous broadcast communication,
The number of times the database is accessed can be reduced, and the waiting state for data processing can be reduced.

As described above, the amount of data waiting to be processed can be reduced while various data is input, the buffer capacity of each input / output port can be reduced, and the data transmission efficiency can be improved.

Further, since the relay load of each relay processing means is reduced, relatively low speed hardware (processor, bus, etc.) for executing each processing function can be used, and the cost of the entire apparatus can be reduced. It can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a network configuration in which an inter-LAN connecting device of a first embodiment according to the present invention is used.

FIG. 2 is a diagram showing a structure of a frame transmitted between networks.

FIG. 3 is a diagram showing a configuration of a LAN-to-LAN connecting device of the first embodiment.

FIG. 4 is a diagram showing a configuration of a route control unit of the inter-LAN connecting device of FIG.

FIG. 5 is a diagram showing a configuration of a LAN-to-LAN connecting device of a second embodiment.

FIG. 6 is a diagram showing a configuration of a LAN-to-LAN connecting device of a third embodiment.

FIG. 7 is a diagram showing a configuration of a LAN-to-LAN connecting device of a fourth embodiment.

FIG. 8 is a diagram showing a configuration of an inter-network connection unit of the inter-LAN connection device of FIG.

FIG. 9 is a diagram showing a configuration of a LAN-to-LAN connecting device of a fifth embodiment.

10 is a diagram showing a configuration of a bus arbiter of the inter-LAN connecting device of FIG.

FIG. 11 is a diagram showing a frame switch of a conventional inter-LAN connecting device.

[Explanation of symbols]

1 ... Inter-LAN connection device, 2a to 2n ... Network, 3
a to 3n ... client machine, 4a to 4n ... server machine, 10a to 10n, 51a to 51n, 59a to 59
n ... LAN I / F, 11 ... Route information database, 12 ... Database control, 13 ... Interconnection circuit, 14a
-14n, 52a-52n ... Path control part, 56 ... Multicast frame buffer, 53 ... Switch, 54 ... Switch control part, 57a-57n ... Multicast buffer, 58a-58n ... Multicast control part.

Claims (6)

[Claims] 1. An inter-network connection device, which is interposed between networks and relays frames containing destination information transmitted between them, a receiving means for receiving the frames transmitted between the networks. A destination extracting unit that extracts destination information from the frame received by the receiving unit; and whether the frame is for individual communication or for simultaneous broadcast based on the destination information extracted by the destination extracting unit. A first relay processing unit that relays a frame identified by the identification unit as an individual communication; and a frame identified by the identification unit as a broadcast communication An inter-network connection device comprising: a second relay processing unit that performs a relay process through a route different from the first relay processing unit. 2. An inter-network connection device, which is provided between networks and relays frames containing destination information transmitted between them, a receiving means for receiving the frames transmitted between the networks. A destination extracting unit that extracts destination information from the frame received by the receiving unit; and whether the frame is for individual communication or for simultaneous broadcast based on the destination information extracted by the destination extracting unit. And a switch having a plurality of input ports to which the individual communication frames are input and a plurality of output ports for transmitting the frames input to these input ports to a desired destination, A switch controller that controls the switch and connects the input port to which the frame is input and the output port corresponding to the destination. And a broadcast processing means for performing relay processing for transmitting the broadcast frame to a plurality of desired destinations, and outputting to the switch the frame identified by the identifying means as for individual communication. In addition, the inter-network connection device further comprises: a route control means for outputting the frame identified as the one for the broadcast communication to the broadcast processing means. 3. The inter-network connection device according to claim 2, wherein the broadcast processing unit stores a grouping database in which transfer control information indicating transfer permission / prohibition between a source and a destination on the network is accumulated. And a broadcast processing unit that relays a frame identified by the identifying unit as one for the broadcast communication only to a transferable destination with reference to the grouping database. Inter-network connection device. 4. An inter-network connection device, which is interposed between networks and relays frames containing destination information transmitted between them, a receiving means for receiving the frames transmitted between the networks. A destination extraction unit that extracts destination information from the frame received by the receiving unit; and whether the frame is for simultaneous broadcast or individual communication based on the destination information extracted by the destination extraction unit. Identification means for identifying whether the individual communication frame is relayed, a second bus for relaying the broadcast communication frame, and a communication content identified by the identification means. Transfer control means for transferring the frame received by the receiving means to each destination separately for the first bus or the second bus. An inter-network connection device characterized by: 5. An inter-network connecting device which is provided between networks and relays a frame including destination information transmitted between each other, wherein route information for a plurality of destinations on the network is accumulated. Route information accumulating means, receiving means for sequentially receiving frames transmitted between the networks, destination extracting means for extracting destination information from the frames received by the receiving means, and destination extracting means Destination information storage means for storing destination information, and first relay processing means for searching the route information storage means based on the destination information in the destination information storage means, setting a corresponding route, and relaying the frame. And when the next frame is received by the receiving means, the next destination information extracted by the destination extracting means and the destination information If the comparison means for comparing the destination information already stored in the information storage means and the comparison result by the comparison means show that the destination information matches each other, the frame is set on the route already set corresponding to the destination. An inter-network connection device comprising: a second relay processing unit that performs relay processing. 6. The inter-network connection device according to claim 5, wherein when the result of the comparison by the comparing means indicates that the destination information does not match each other, the content stored in the destination information storing means is changed to that of the next frame. An inter-network connection device further comprising an updating means for updating.