JPH0695674B2 - Line bridge - Google Patents

Description

The present invention relates to a line bridge configured by connecting a plurality of lines of different types, and particularly to registration and deletion of terminals directly managed by each communication node. Regarding those having functions.

[Conventional technology]

As a method of constructing a relatively large-scale system within a LAN (LOCAL AREA NETWORK), there is a method of connecting multiple lines of different types. That is, the terminals at the end are divided into several groups, each of these divided groups is made to correspond to one communication node, and these communication nodes and the terminal groups below are connected by a line with low transmission capacity,
In this method, each communication node is connected by a line having a high transmission capacity to construct one network system. A line bridge is used to control transmission by connecting different types of lines to each other. Conventional basic functions of this line bridge are, for example, IEEE (INSTITUTE OF E
LECTRIC AND ELECTRONICS ENGINEERING) There were three main types as specified in 802.1.

(1) Connect multiple stations that have the same LCC (LOGICAL LINK CONTROL) layer or higher but different MAC (MEDIUM ACCESS CONTROL) layers or lower, and convert the MAC layer or lower to control transmission while maintaining consistency between stations Ability to do.

(2) A control function for reducing communication traffic. That is, the destination terminal is checked from the destination address of the received frame, and if the communication node to which this destination terminal belongs is the same as the communication node that transmitted this frame, it is determined that the transmission is between terminals belonging to the same communication node. Discard. If no communication node having this destination terminal exists, this frame is transmitted to all other communication nodes except the communication node that transmitted the frame. When there is another communication node having this destination terminal, the frame is transmitted to this communication node.

(3) A function of sequentially updating the registration setting status of the communication node of the terminal. That is, the line bridge has a terminal entry composed of the address of the terminal accommodated by each communication node, checks the source address of the received frame, and deletes from the terminal entry if this address does not appear for a certain time or longer in the terminal entry. To do one after another. If there is a terminal newly added to the communication node, the address of that terminal is registered in the terminal entry.

Conventionally, there are two methods of realizing the above functions (2) and (3) among the three functions of the line bridge, that is, the centralized distributed management method and the multiple distributed management method.

First, the centralized distributed management method will be described. In this method, the terminal entries that each communication node has independently include the addresses of all the communication nodes on the line bridge and the addresses of all the terminals registered under these as a pair. Then, each communication node sequentially updates its own terminal entry according to the frame received from the terminal below it, and refers to the terminal entry of another communication node by exchanging the updated terminal entry with another communication node. As a result, each communication node centrally manages the distributed terminal entries as a whole.

Next, the multiple distributed management method will be described. In this method, the terminal entries that each communication node has independently include the addresses of all the communication nodes on the line bridge and the addresses of all the terminals registered under these as a pair. Then, each communication node sequentially updates its own terminal entry with both the frame received from the terminal below and the frame received from the line bridge.

[Problems to be solved by the invention]

In the above-mentioned unified decentralized management method, each communication node needs to update its own terminal entry by the frame received from the terminal therebelow, and then exchange the updated terminal entry with another communication node. Since this exchange process must be performed for all other communication nodes on the line bridge, the processing capability of the communication node is reduced.

Further, in the above-mentioned multi-source distributed management method, it is necessary for each communication node to update the terminal entry based on these not only for the frame received from the terminal therebelow but also for the frame received from the line bridge This caused a decrease in the processing capacity of the node. Further, since the terminal table is not divided for each communication node, there is a drawback that it is difficult to find the cause of the system failure or the deterioration of the processing capacity.

Therefore, an object of the present invention is to provide a line bridge that performs control for reducing communication traffic without lowering the processing capacity of each communication node, and that sequentially performs terminal registration and deletion processing for a communication node. is there.

[Means for solving problems]

In the circuit bridge of the present invention, a management node for comprehensively managing the terminal table of each communication node is newly installed on the bridge of the conventional multi-distributed management system in addition to the communication node.

That is, when the management node has the terminal tables of all the communication nodes on the line bridge and each communication node updates its own terminal table, it does not process this inside the communication node but always manages it. I made a request to that effect. Upon receiving this, the management node updates its own terminal table, and then sends back this updated terminal table to all communication nodes on the line bridge by broadcast transmission. In addition, all communication nodes on the line bridge receive this and update their own terminal tables.

As a result, when one terminal updates the terminal table in one communication node, the management node can be made to perform the processing of notifying other terminal of the update, so that the load of each communication node can be reduced. As a result, it is possible to perform control for reducing communication traffic without decreasing the processing capability of each communication node, and to sequentially perform terminal registration and deletion processing with respect to communication nodes.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to Examples.

FIG. 1 is a block diagram showing the configuration of a LAN system using a line bridge in one embodiment of the present invention. The line bridge of this embodiment has three communication nodes and one management node. A high-speed bus is used as a communication line (first communication line) connecting each communication node and a management node, while a communication line (second communication line) connecting each communication node and a terminal managed by these nodes is used. CSMA / CD (CARRI
ER SENSE MALTIPLE ACCESS WITH COLLITION DETECTIO
N) A bus was used.

First, each component in the figure will be briefly described. The high-speed bus 11 is a general-purpose bus having a high-speed transmission capability, which connects each communication node and management node. The communication nodes 12 to 14 all have the same configuration and function, and are connected to the high speed bus 11 by the high speed bus interfaces 15 to 17 and the terminal terminals directly managed by them by the CSMA / CD bus interfaces 18 to 20. To do. Management node
The high speed bus interface 22 couples the high speed bus 11 to the high speed bus 11 and manages registration and deletion of all terminals on the communication line bridge with respect to the corresponding communication nodes. The terminal tables 23 to 25 are in the communication nodes 12 to 14, respectively, and each of the communication nodes indicates the registration or deletion state of the terminal under the control of its own communication node and the terminal under the control of other communication nodes. Hold on. Management table
Reference numeral 26 is in the management node 21, and holds the state of registration or deletion of the terminal under the control of the communication node on the line bridge for each communication node. The first node tables 27 to 30 are in the terminal tables 23 to 25 and the management table 26, respectively, and these hold the registration or deletion status of the terminals under the control of the communication node 12. Second
Node tables 31 to 34 are terminal tables 23 to 25, respectively.
And in the management table 26, these are communication nodes
Holds the registration or deletion status of the terminals under the control of 13. The third node tables 35 to 38 are respectively in the terminal tables 23 to 25 and the management table 26, and these hold the registration or deletion status of the terminals under the control of the communication node 14. The terminals 41 and 42 are terminals connected to the communication node 12. The terminals 43 to 45 are terminals connected to the communication node 13. The terminals 46 and 47 are terminals connected to the communication node 14.

FIG. 2 is a block diagram showing the configuration of the communication node. To briefly explain each component in the figure, the terminal table 51 holds the registration or deletion status of the terminals under the control of its own communication node and the terminals under the control of other communication nodes for each communication node. There is. The terminal table management means 52 is composed of a table management means 53, a table updating means 54 and a management communication means 55, which updates its own terminal table 51 and at the same time reports the updated contents to other communication nodes and vice versa. Upon receiving a report about updating the table from another communication node, the corresponding terminal table is updated. CSMA / CD (CARRIER SENSE MALTIPL
The E ACCESS WITH COLLITION DETECTION) bus interface 56 connects a communication node and a terminal under the same with a coaxial cable, and performs communication between these terminals and communication between these terminals and the communication node in a frame format. MAC
The (MEDIUM ACCESS CONTROL) converter 57 converts the frame format of the CSMA / CD bus into the frame format of the high speed bus and vice versa. The high-speed bus interface 58 is an interface unit for connecting the communication nodes or the communication node and the management node by the high-speed bus 11.

FIG. 3 is a block diagram showing the configuration of the management node. To briefly explain each component in the figure, the management table 71 holds, for each communication node, the registration or deletion status of a terminal under the control of each communication node. The management table management means 72 is a table updating means 73, a management communication means
74 and a man-machine interface 75, each of which updates a corresponding portion in the management table when it receives a report about the update of the table from each communication node, and at the same time reports the updated content to each communication node. Further, the man-machine interface 75 is used to update or refer to the management node using the external console 79 and the CRT display 80.

Next, the operation of the line bridge will be described by taking the transfer of the terminal table information between the communication node 12 and the management node 21 as an example.
First, the operation when the communication node starts up will be described. When the power of the communication node 12 is turned on, first, after initializing the system in the communication node 12, the management node 21 is requested to send a terminal table. First, the management communication means 55 issues a table request command to the high-speed bus interface 15 to request the management node 21 to send a terminal table. The high-speed bus interface 15 receives this and creates a table request frame, and sends this to the management node 21. The table request frame is received by the high speed bus interface 22 of the management node 21 via the high speed bus 11.
The high-speed bus interface 22 reproduces the table request command from the received table request frame and passes it to the management communication means 74. When the management communication means 74 receives this table request command, it sends the terminal table 71 to the communication node 12.
Will be sent back. In the communication node 12, when the high speed bus interface 15 receives the terminal table sent from the management node 21, the management communication means 55 instructs the table updating means 54 to register the terminal table. The table updating means 54 registers the terminal table group sent thereto in the terminal table 51. At the same time, the management node 21 is notified of the end of this registration by the same procedure as above. As a result, the terminal address in the initial state is registered in the terminal table 51 of the communication node 12. In the communication node 12, the table management means 53 is then activated and management of the first node table 59 is started. Each time the management node 21 receives a table request command from the communication node 13 and the communication node 14, it also sends a terminal table to these and registers the terminal address in the initial state.

Next, the case of additionally registering the terminal address in the communication node will be described. First, the communication node 12 searches the first node table 59 based on the source terminal address of the frame received from the CSMA / CD bus interface 56. When the source terminal address is not registered in the first node table 59, the registration request is sent to the management communication means 55. In response to this, the management communication means 55 issues a registration request command to the high-speed bus interface 58 to make a registration request to the management node 21. The high-speed bus interface 58 receives this, creates a registration request frame, and transmits this to the management node 21. The registration request frame is received by the high speed bus interface 22 of the management node 21 via the high speed bus 11. The high-speed bus interface 22 reproduces the registration request command from the received registration request frame and passes it to the management communication means 74. When the management communication unit 74 receives this registration request command, the management communication unit 74 requests the table updating unit 73 to register the terminal address. Upon receiving this, the table updating means 73 additionally registers the terminal address in the first node table 76.
After the table updating means 73 additionally registers this, the management communication means 74 issues a command to register the terminal address to the communication node 12. In the communication node 12, when the registration command sent from the management node 21 is received by the high-speed bus interface 11, the management communication means 55 instructs the table updating means 54 to additionally register the terminal address. Upon receiving this, the table updating means 54 additionally registers the terminal address in the first node table 59. At the same time, the management node 21 is notified of the end of this registration by the same procedure as above. As a result, the terminal address is additionally registered in the first node table 59 of the communication node 1. The management node 21 also issues a terminal address registration command to the communication node 13 and the communication node 14 to additionally register the terminal address in the terminal tables of these communication nodes.

Next, the case of deleting the terminal address from the communication node will be described. The table management means 53 of the communication node 12 is the first
Timer monitoring is performed for each terminal address in the node table 59 of FIG. That is, when a frame is received from the CSMA / CD bus interface 56, the sending terminal address of this frame is searched from the first node table 59, and the result of the search is the first
When this terminal address is found in the node table 59 of, the timer related to this terminal address is reset. If the terminal address is not found, the timer for this terminal address is reset when the table updating means 54 additionally registers this terminal address. When each timer reaches a specified value, it is known that the corresponding terminal has been unused for a certain period of time or more, so the table management means 53 manages the deletion request of this terminal address by the management communication means.
Put on 55.

In this embodiment, at least 30 is required to move the terminal and start communication.
Taking into account that it takes time,
It took 20 minutes. If the set time of the timer is longer than the minimum relocation time, even after the relocation of the terminal, there will be a period when this terminal is registered as the terminal address before the relocation, so this terminal will be registered under the new terminal address by the relocation. This is inconvenient because a double registration state can occur. In order to avoid such problems, adopt a method such as changing the timer installation time according to the transfer time of each terminal, and not deleting the terminal address by the timer for terminals that are not transferred. You can also

Next, the management node will be additionally described. In the management node 21, by connecting the CRT display 80 and the console 79 by the man-machine interface 75, the maintenance person gives a command for reading the terminal table 71 from the console 79 to the table updating means 73 to show the registration status of the terminal table in the CRT display 80. Can be displayed on. Further, a command for updating the terminal table 71 from the console 79 can be given to the table updating means 73 to register the terminal address in the terminal table 71 or delete the terminal address from the terminal table 71 by manual operation.
At this time, when the terminal table of the management node is updated, the management node 21 issues a registration instruction or a deletion instruction to each communication node to make a change to the terminal table of each communication node, and issues a registration instruction or deletion instruction to each communication node. Needless to say, the terminal table of is updated.

Next, the communication between the CSMA / CD bus will be briefly described. Communication node 12 is from CSMA / CD bus interface 56 to CSMA / CD
Receive all CSMA / CD bus frames sent on bus 62 once regardless of their destination address.

Next, the MAC conversion unit 57 extracts the destination address from this CSMA / CD bus frame and checks whether or not this is registered in the terminal table 51. If there is the same terminal address in the first node table 59, this CSMA / C
Since the D bus frame is a communication frame between terminals accommodated in the communication node 12, it is discarded. When the same terminal address as this is found in the second node table 60 or the third node table 61, the MAC conversion unit 57 forms a high speed bus frame from this CSMA / CD bus frame and sets it as a high speed bus. Send to interface.

That is, the node address of itself is added to this CSMA / CD bus frame as the source node address, and the node address of the communication node 13 or the communication node 14 is added as the destination node address. Furthermore, the information CNT indicating the communication between the CSMA / CD bus is used as a header, and the FCS (FRAM
E CHECK SEQUENCE) is added as a trailer to create a high-speed bus frame. If this destination address is not found in the terminal table 51, the MAC conversion unit 57 uses the broadcast address of the high-speed bus as the destination node address to send it to both the communication node 2 and the communication node 3. .

When the communication node 12 receives the high speed bus frame from the high speed bus 11, the control field CNT is examined, and when it is the communication between the CSMA / CD buses, the MAC conversion unit 57 removes the header and the trailer from the high speed bus frame to remove the CSMA / CD. Create a bus frame and connect it to the CSMA / CD bus interface 56
Send to CD Bus 62.

FIG. 4 is a sequence diagram showing the operation of the bus bridge described above. In this sequence explanatory diagram, communication between the communication node 81, the communication node 82, and the management node 83 is shown as an example.

First, when the communication node 81 is activated by the activation 84, the management communication means 85 transmits a terminal table request to the management communication means 86 of the management node 83 via the high speed bus 11. Management communication means 86
When it receives this, it notifies the table updating means 87 of that fact, and the table updating means 87 receives this and performs the table reading 88, transmits the terminal table to the communication node 81 via the management communication means 86, and updates the table. The means 89 receives this and creates the table 90. After updating the table 90, the table updating means 89 returns a response to the management node 83.

This completes the startup of the communication node 81.

Next, the communication node 82 whose startup has been completed by the same procedure as above.
When a table change request 91 occurs in the communication node 82
Notify the management communication means 92 of that. Management communication means 92
In response to this, sends to the management communication means 86 of the management node 83 a table change request including information on addition or deletion of terminal addresses. When the management communication means 86 of the management node 83 receives this and notifies the table update means 87 of this, the table update means 87 adds or deletes the corresponding terminal address by the table change 93. When this is completed, the management communication means 86 first sends to the communication node 81 a table change instruction containing the result of changing the corresponding terminal address. In response to this, the table updating means 89 in the communication node 81 receives the result of the terminal address change via the management communication means 85, and makes a necessary change to the second node table 31 by the table change 94, and this ends. And returns a response to the management node 83. Management communication means of the management node 83
Upon receiving this response, 83 subsequently transmits the same table change instruction to communication node 82 as it did to communication node 81. When the communication node 82 receives this, the table updating means 95 changes the table 96, so that the necessary change is made to the second node table 32, and when this is completed, a response is returned to the management node 83. The management node 83 receives this and completes the table change instruction.

Next, a case where the maintenance person manually changes the terminal table will be described. The maintenance person inputs the change request 97 from the console 79. When the management node 83 receives this change request input 97 via the man-machine interface 98, it is the same as when it receives the table change request from the communication node 2 described above after performing the table change 99 by the table updating means 87. According to the procedure, the table change instruction is sequentially issued to the communication node 81 and the communication node 82. When the communication node 81 and the communication node 82 receive this table change instruction, after making necessary additions or deletions to their own terminal tables by the table change 101 and the table change 102,
It returns a response to the management node 83. The management node 83 receives this and completes the change request input process.

At this time, if an MT (MAGNETIC TAPE) unit or a disk unit is connected to the management node 83, the terminal table can be managed as a file.

〔The invention's effect〕

As described above, according to the present invention, a management node for comprehensively managing the terminal table of each communication node is newly installed on the bridge of the conventional multi-distributed management system in addition to the communication node.

When this management node has the terminal tables of all the communication nodes on the line bridge and each communication node updates its own terminal table, it does not handle this only inside the communication node, but by all means. The management node was requested to do so. Upon receiving this, the management node updates its own terminal table, and then sends back this updated terminal table to all communication nodes on the line bridge by broadcast transmission. In addition, all communication nodes on the line bridge receive this and update their own terminal tables.

As a result, when one communication node updates the terminal table, the process of notifying the other communication node of this can be delegated to the management node, so that the load of each communication node can be reduced. . As a result, it has become possible to perform control for reducing communication traffic without deteriorating the processing capability of each communication node, and to successively perform terminal registration and deletion processing with respect to communication nodes.

In addition, when the system breaks down or the processing capacity decreases, the maintenance personnel can more easily find the cause than before.

[Brief description of drawings]

1 to 4 are for explaining one embodiment of the present invention. Of these, FIG. 1 shows the configuration of a line bridge in which three communication nodes and one management node are connected by a high-speed bus. 2 is a block diagram showing the configuration of a communication node, FIG. 3 is a block diagram showing the configuration of a management node,
FIG. 4 is a sequence diagram showing the operation of the line bridge. 11 …… High-speed bus, 12,13,14 …… Communication node, 15,16,17 …… High-speed bus interface, 18,19,20 …… CSMA / CD bus interface, 21 …… Management node, 23,24, 25 …… Terminal table, 26 …… Management table, 57 …… MAC converter, 75 …… Man-machine interface, 79 …… Console, 80 …… CRT display.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location 7341-5K H04L 11/00 320

Claims (1)

[Claims] 1. Each has two types of communication line interfaces and a terminal table, uses a first communication line to connect itself and other nodes, and connects itself and a plurality of terminals directly managed by itself. A second communication line, and the terminal table holds a plurality of communication nodes having the same function of holding the node addresses of all the communication nodes and the terminal addresses of the terminals belonging to each communication node as a set; One communication line has a line interface and a management table, and is coupled to the plurality of communication nodes by the first communication line, and one of the plurality of communication nodes owns itself through the first communication line. When the terminal registration information is sent, the terminal registration information is received and recorded in the management table, and then all the terminal registration information is transferred to the plurality of terminals via the first communication line. A line bridge comprising: a management node that returns the data to all communication nodes by broadcast transmission.