JP2508590B2 - Network control system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a network such as a LAN (Local Area Network), and more particularly to a network control system for controlling the traffic volume of the network.

[0002]

2. Description of the Related Art In recent years, in offices, factories, etc., a LAN for exchanging information by mutually connecting computer terminals.
Etc. networks are widely spread. Past LA
In a network system such as N, a method of automatically adjusting the amount of data (traffic amount) flowing on the cable so that it is always within a certain specified value has not been realized.

A conventional system for controlling traffic in a network is disclosed in Japanese Patent Laid-Open No. 2-92043. In this system, whether or not the buffer state for receiving data of a terminal is receivable is monitored, and when the buffer is unreceivable, the terminal is kept busy for a certain period of time to adjust the traffic volume.

[0004]

In the conventional network system, as described above, a method of automatically adjusting the amount of data (traffic amount) flowing on the cable so that it is always within a certain specified value is realized. Not not. Therefore, when more than the number of terminals that are supposed to be used for network construction are transmitting data at the same time, the traffic volume increases and the response speed of the terminals becomes unacceptably slow. If the value exceeds the maximum, the entire network might stall (system down). Further, in the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 2-92043, when a receiving buffer of a terminal becomes unreceivable, the terminal is simply put in a busy state, so that the traffic volume on the network is always constant. It is impossible to control the value to be equal to or less than the value, and the above-mentioned problem may occur.

The present invention has been made in order to solve such a conventional problem, and is a network control system capable of automatically controlling so that the traffic amount on a network cable is always within a certain value. The purpose is to provide.

[0006]

In order to achieve the above object, the network control method of the present invention is a network control system in which a plurality of terminals are connected by a network cable and data is exchanged between the terminals. To disconnect a specific terminal of the plurality of terminals from the network cable when the detected traffic amount is compared with a preset specified value and the traffic amount exceeds the specified value. Between the network cable and the specific terminal, which issues control data for issuing the control data for connecting the specific terminal separated to the network cable when the control data is issued below the specified value. Depending on the content of the control data from the traffic monitoring means. It has a configuration comprising a terminal control means for performing re-connect and disconnect of the specific terminal. Further, in the network control method according to claim 2, the traffic monitoring unit calculates a traffic amount on the network, a determination unit that determines the magnitude of the traffic amount and the specified value, and the determination result. The terminal control means recognizes the control data from the traffic monitoring means, and whether the control data is control data addressed to itself. It is composed of a judging means for judging whether or not there is any, and a means for disconnecting or reconnecting the specific terminal from the network cable according to an instruction of the control data when the control data is addressed to itself. The network control method according to claim 3 is
Control in which the control data issued by the traffic monitoring unit is composed of an address designating the specific terminal and instruction data instructing disconnection or reconnection of the specific terminal designated by the address from the network cable. It is a packet.

[0007]

In the present invention, the traffic monitoring means constantly monitors the number of packets flowing on the cable and calculates the traffic amount. The calculated traffic volume is compared with a specified value to determine the magnitude of the specified value. When the calculated traffic volume exceeds the specified value, control data that specifies disconnection of a specific terminal that is determined to be disconnected from the cable when the traffic volume exceeds the specified value is generated and transmitted. If the traffic volume is less than or equal to the specified value, the control data designating reconnection of the terminal disconnected from the cable is generated and transmitted. The terminal control means receives the control data and performs a process of disconnecting the terminal managed by itself from the cable or a process of reconnecting the terminal according to the content of the control data.

[0008]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows the configuration of an embodiment of a LAN (local area network) to which the present invention is applied.
The LAN system of this embodiment is a bus type LAN,
Ethernet cable 10 and Ethernet cable 1
A plurality of tap transceivers 11 and 12a provided on 0
12n, a traffic monitoring device 15 connected to the Ethernet cable 10 via the tap transceiver 11 and the branch cable 13, and a tap transceiver 12
a to 12n and a plurality of traffic control units 16a to 16n connected to the Ethernet cable 10 via the branch cables 14a to 14n, and a branch cable 17a.
.About.17n, and a plurality of terminals 18a to 18n connected to the traffic control units 16a to 16n.

Between the tap transceiver 11 and the traffic monitoring device 15, the tap transceivers 12a to 12a-1.
2n and the traffic control units 16a to 16n, and between the traffic control units 16a to 16n and the terminals 18a to 18n.
The interfaces between the two are the same. Therefore, the branch cables 13, 14a to 14n and 17
The lengths of the three types of cables a to 17n are different, and the shape of the connector and the function of each signal line in the cable are the same.

Tap transceivers 11, 12a-12n
Converts the signals from the traffic monitoring device 15 and the terminals 18a to 18n into signals suitable for the Ethernet cable 10 and sends the signals, and conversely converts the signals from the Ethernet cable 10 to the traffic monitoring device 15 and terminals 18a to 18n.
It is converted into a suitable signal and sent.

The traffic monitoring device 15 constantly monitors the number of packets flowing on the Ethernet cable 10 to detect the traffic amount, and compares the detected traffic amount with a preset specified value. When the traffic volume exceeds the specified value, a traffic control packet for disconnecting a specific terminal from the Ethernet cable 10 among the plurality of terminals 18a to 18n is issued. On the contrary, when the value is equal to or less than the specified value, a traffic control packet for reconnecting the separated specific terminal to the Ethernet cable 10 is issued. FIG. 2 is a block diagram showing a configuration example of the traffic monitoring device 15.
From the traffic amount calculation means 151 for calculating the traffic amount from the number of packets flowing over 0, the control means 152 for comparing the calculated traffic amount with a prescribed value to determine whether or not it exceeds the prescribed value, and the control means 152. The control packet generation means 153 for generating and transmitting the traffic control packet based on the determination signal In addition,
The prescribed value of the traffic volume, which serves as a reference for determining whether or not to disconnect a specific terminal, is preset in the control unit 152. As for the specific terminal to be disconnected when the traffic volume exceeds the specified value, one or a plurality of terminals may be determined in advance, or the connected terminals 18a to 18a.
You may select arbitrarily from 8n.

The traffic control units 16a to 16n receive a traffic control packet sent from the traffic monitoring device 15 and perform a process of disconnecting and reconnecting a specific terminal according to the content of the traffic control packet. FIG. 3 is a block diagram showing a configuration example of the traffic control units 16a to 16n, and receives a traffic control packet from the terminal connection control means 161 that performs disconnection processing and reconnection processing of a specific terminal, and the traffic monitoring device 15. The control packet receiving means 162 and the address determining means 163 for determining whether or not the received traffic control packet is addressed to itself.

FIG. 4 shows the format structure of the traffic control packet sent from the traffic monitoring device 15. The traffic control packet 40 is composed of a header 41 and a data field 42. In the header 41, a MAC address designating any of the terminals 18a to 18n to be controlled is set, and in the data field 42, the terminals 18a to 18n designated by the header 41 are disconnected from the Ethernet 10 or reconnected. Set the control data of whether to do. In this embodiment, the traffic control packet 40 has a bit length of 256 bits,
Header 41 is 48 bits and data field 42 is 20
It has 8 bits. In the data field 42, all bits "0" or "1" are set. All bits ”
When it is 0 ", it means that the terminal specified by the MAC address of the header 41 is logically disconnected from the Ethernet cable 10. When all bits are" 1 ", the MA of the header 41 is
Ethernet cable 10 for the terminal specified by C address
Means to reconnect to.

Next, the operation of the network control system configured as described above will be described with reference to FIGS. FIG. 5 is a flowchart illustrating the operation of the traffic monitoring device 15. Traffic monitoring device 15
Constantly monitors the number of packets flowing on the Ethernet cable 10, and the traffic amount calculation means 151 calculates the traffic amount from the number of packets (step 50).
1). The control means 152 compares the calculated traffic volume with a specified value and judges the size of the specified value (step 502). The determination result is notified to the control packet generation means 153.

When the calculated traffic amount exceeds the specified value, the control packet generating means 153 which has received the notification.
Sets, in the header 41, an address designating a specific terminal which is determined to be disconnected from the Ethernet cable 10 when the traffic volume exceeds a specified value,
And in the data field 42, Ethernet cable 1
A traffic control packet 40 is generated by setting all the bits "0" which specify to be separated from 0, and is flown on the Ethernet cable 10 (step 50).
3).

When the traffic volume is equal to or less than the specified value, the control packet generation means 153 determines whether or not the terminals 18a to 18n disconnected from the Ethernet cable 10 exist (step 504) and is in the disconnected state. When there is no terminal, the control packet 40 is not generated. Terminals 18a-1 separated in step 504
When 8n exists, all the bits that specify the address for designating the terminal disconnected from the Ethernet cable 10 in the header 41 and the data field 42 for reconnecting to the Ethernet cable 10 "
By setting 1 ", a traffic control packet 40 is generated and sent on the Ethernet cable 10 (step 503).

FIG. 6 shows traffic control units 16a-16.
It is a flow chart explaining operation of n. Control packet receiving means 162 of the traffic control units 16a to 16n
When the traffic control packet 40 flowing on the Ethernet cable 10 is received (step 601), the address determination means 163 receives the traffic control packet 40.
It is determined whether or not the MAC address set in the header 41 of the terminal matches the address of the terminal under its control (step 602). If the addresses do not match, the received traffic control packet 40 is ignored.

When the addresses match, the fact is notified to the terminal connection control means 161. Terminal connection control means 16
In 1, the contents of the data field 42 are read and it is determined whether all the bits are "0" or "1" (step 60).
3). If all bits of the data field 42 are "0", the subordinate terminal is logically disconnected from the Ethernet cable 10 (step 604), and a cable disconnection pseudo fault notification is sent to the terminal (step 605). As a result, data transmission from the separated specific terminal and data reception by the specific terminal are prohibited.

If all bits of the data field 42 are "1", the terminal connection control means 161 reconnects the terminal under its control to the Ethernet cable 10 (step 606), and disconnects the cable from the terminal. The failure is repaired (step 607). This enables data transmission from a specific terminal and data reception by a specific terminal.

As described above, by disconnecting and reconnecting the specific terminal based on the traffic amount, the traffic on the Ethernet cable 10 is always controlled to be equal to or less than the predetermined specified value. Although the present invention has been described with reference to the preferred embodiments, the present invention is not necessarily limited to the above embodiments. For example, in the above embodiment, an example in which the present invention is applied to Ethernet which is a bus type LAN is shown. However, a star type or ring type LA is used.
It goes without saying that it is also applicable to N. It can also be applied to networks other than LAN.

[0021]

As described above, according to the network control method of the present invention, when the traffic volume on the network cable exceeds a specified value, a specific terminal is disconnected from the network cable, and when the traffic is below the specified value, By connecting the separated specific terminal to the network cable, the traffic on the cable can be automatically controlled so as to be equal to or less than a predetermined specified value. Therefore, it is possible to eliminate the possibility that the entire network stalls when the traffic volume becomes large and the response speed of the terminal becomes unacceptably slow, or when the traffic volume greatly exceeds the processing capacity of the network.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a LAN system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration example of a traffic monitoring device.

FIG. 3 is a block diagram showing a configuration example of a traffic control unit.

FIG. 4 is a diagram showing a frame structure of a traffic control packet.

FIG. 5 is a flowchart illustrating the operation of the traffic monitoring device of this embodiment.

FIG. 6 is a flowchart illustrating an operation of a traffic control unit according to the present exemplary embodiment.

[Explanation of symbols]

 10 Ethernet Cable 11, 12a to 12n Tap Transceiver 15 Traffic Monitoring Device 16a to 16n Traffic Control Unit 18a to 18n Terminal 40 Traffic Control Packet 41 Header 42 Data Field 151 Traffic Amount Calculation Means 152 Control Means 153 Control Packet Generation Means 161 Terminal Connection Control Means 162 Control packet receiving means 163 Address judging means

Claims (3)

(57) [Claims] 1. In a network in which a plurality of terminals are connected by a network cable and data is exchanged between the terminals, the traffic amount on the network cable is detected, and the detected traffic amount is set to a preset specified value. if the traffic volume compared to exceeds the specified value, issues control data for disconnecting the specific terminal from the network cable of the plurality of terminals, before
If the traffic volume is less than the specified value and the traffic is disconnected
When the specific terminal exists, a traffic monitoring unit that issues control data for connecting the separated specific terminal to the network cable, and is connected between the network cable and the specific terminal, The control data from the traffic monitoring means
Determines whether the data is control data addressed to itself, and
A network control method comprising: terminal control means for disconnecting and reconnecting the specific terminal according to the content of the control data from the traffic monitoring means when the control data is addressed to itself . 2. The traffic monitoring means, a calculating means for calculating the traffic volume on the network, a determining means for determining the magnitude of the traffic volume and the specified value, and control data based on the determination result. A control data generation unit for generating the control data, the terminal control unit recognizing the control data from the traffic monitoring unit, and determining whether or not the control data is control data addressed to itself. 2. A means for disconnecting or reconnecting the specific terminal from the network cable according to an instruction of the control data when the control data is addressed to itself. Described network control method. 3. The control data issued by the traffic monitoring means includes an address designating the specific terminal, and instruction data designating disconnection or reconnection of the specific terminal designated by the address from the network cable. 3. The network control method according to claim 1, wherein the network control method is a control packet configured by.