JPH06120960A - Trunk station - Google Patents

Abstract

PURPOSE:To improve the utilization efficiency of a trunk LAN by reducing the number of channels and repeater connecting the stay LAN of duplexed ring. CONSTITUTION:The stay LAN 2 and 3 provided with primary and secondary rings for transferring communication data and data for monitoring in reverse direction mounted on the trunk LAN 1 provided with the primary and secondary rings for transferring the communication data in the reverse direction are provided in connected trunk stations S1 and S2. A trunk LAN basic part 10 for exchanging the communication data of the primary and secondary rings of the trunk LAN and a stay LAN interface 20 for transmitting the communication data to the primary ring of the trunk LAN under the permission of the trunk LAN basic part at the time of a normal connection mode and at the time of receiving the communication data of the primary ring of the stay LAN, then internally bypassing the data for monitoring of the secondary ring of the stay LAN and sending them back to the secondary ring of the stay LAN are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trunk line station used for a computer network system having a dual ring transmission line, an operating system, etc. Local area network) to a trunk station that realizes channel reduction while connecting to a repeater.

[0002]

2. Description of the Related Art A typical example of this type of system is a LAN system. This LAN system is connected to a main line LAN to which a plurality of main line stations are connected using a duplex ring transmission line, and to a main line station of this main line LAN, and a branch line station is also connected to the main line station using the double ring transmission line. And a branch line LAN for controlling connection of various lower terminal devices.

The duplex ring transmission line of the trunk LAN is
One of the ring transmission lines is called the primary ring,
The other ring transmission path is called a secondary ring, and communication data flows in the opposite directions. Therefore, in the case of the trunk LAN, the communication data can be transferred in both directions regardless of the state of the transmission line, and the transmission line is composed of a plurality of channels for time division multiplex transmission. The trunk line station of this trunk line LAN has a repeater connection function for transmitting data from the branch line LAN to the trunk line LAN as it is, and also has a function for transmitting / receiving data to / from the branch line LAN through a channel.

On the other hand, the duplicated ring transmission line of the branch line LAN also has a primary ring and a secondary ring, so that data flows in mutually opposite directions like the duplicated ring transmission line of the branch line LAN. Has become
Normally, data communication is performed using the primary ring,
The secondary ring is of a type that monitors the disconnection of the transmission path by sending synchronization symbols and the like without passing data.

However, in the following special cases, data may flow through the secondary ring transmission line. That is, when the branch line station is powered on, loopback is performed for connection control of an adjacent mainline station, or when loopback is performed while transmitting / receiving data when a transmission line is abnormal.

Therefore, in such a LAN system, each branch line LAN is subordinately synchronized with one main station which is a master station, and among them, a branch line station connected to the branch line LAN serves as a lower terminal device. For example, when performing transmission control by a circuit-switched terminal device, or when connecting a plurality of branch line LANs, unless a repeater connection is established, the terminals cannot be synchronized and a plurality of branch line LANs cannot be connected. become.

Therefore, the main line station is a branch line LAN.
In addition to the interface function of the branch line LAN, it is necessary to have a function of connecting both the primary and secondary sides of the branch line LAN to the trunk line LAN without being involved in the contents of the data. For that purpose, the trunk line station needs two channels for primary and secondary channels for each branch line LAN in relation to the trunk line LAN.

[0008]

Therefore, in the LAN system as described above, when the trunk line station connects the branch line LAN with the repeater, the secondary line of the branch line LAN is usually used.
Main line LAN despite not using ring transmission line
In addition to the primary ring, a channel for the secondary ring is required on the upper side, and if there are n branch line LANs connected to a certain trunk station, 2 channels are required.
Since n channels are required and one connection control channel is prepared for monitoring / controlling the other main LAN, it is necessary to provide an extremely large number of channels.
The transmission efficiency with respect to the transmission capacity becomes very poor.

The present invention has been made in view of the above circumstances, and when connecting a dual ring branch line LAN to a repeater LAN on a main line LAN, it is possible to connect on the main line LAN using almost half of the channels as compared with the conventional one. Therefore, it is an object of the present invention to provide a main line station for improving the transmission efficiency on the main line LAN.

[0010]

In order to solve the above-mentioned problems, the invention corresponding to claim 1 is a trunk line having a primary ring transmission line and a secondary ring transmission line for respectively transferring communication data in opposite directions. In a trunk line station mounted on a LAN and connected to a branch line LAN having a primary ring transmission line and a secondary ring transmission line for transmitting communication data and transmission line monitoring data in opposite directions,

A trunk LAN station basic unit for receiving communication data of the primary ring transmission path and the secondary ring transmission path of the trunk LAN and transmitting the communication data to the corresponding ring transmission path of the trunk LAN, and in a normal connection mode, When the communication data of the primary ring transmission line of the branch line LAN is received, the communication data is transmitted under the permission of the basic section of the main line LAN station.
When the transmission line monitoring data of the secondary ring transmission line of the branch line LAN is received while transmitting to the primary ring transmission line of the trunk line LAN via the station basic unit, the branch line LAN is internally bypassed. This is a trunk line station provided with a branch line LAN interface for returning to the secondary ring transmission line.

Next, the invention corresponding to claim 2 is the trunk line L
Primary and secondary transmission / reception control means for receiving communication data of the primary ring transmission path and the secondary ring transmission path of the AN and transmitting the communication data to the corresponding ring transmission paths of the trunk LAN, respectively.

In the normal connection mode, when the communication data of the primary ring transmission line of the branch LAN is received, the communication data is transmitted and received by the basic section of the trunk LAN station under the permission of the basic section of the trunk LAN station. When the transmission line monitoring data of the secondary ring transmission line of the branch line LAN is received while transmitting to the primary ring transmission line of the trunk line LAN via the control means, the data is monitored internally to bypass the branch line LAN. First branch LAN connection control means for returning to the secondary ring transmission line,

When the branch LAN ring is started up, after confirming the connection of the branch LAN connected to itself, second branch line LAN connection control means for outputting a notice to start the connection control, and the second branch line LAN. A first transmission to the other mainline station via the mainline LAN that the branch line LAN connected to itself is connected using the connection control channel of the mainline LAN when notified by the connection control means.
Second trunk line L which outputs a connection control permission when the connection notification of the trunk LAN basic control means of the above and another branch line LAN connected to itself is received from the other trunk line station.
Based on the connection control start permission from the AN basic control means and the second main LAN basic control means, the main LAN
And the primary ring data of the branch line LAN to the primary ring data of the branch line LAN and the trunk line LAN, respectively.
The trunk line station is provided with a transmission line control means for transmitting to the ring transmission line and for transmitting the secondary ring data of the trunk line LAN and the branch line LAN respectively using the connection control channel.

[0015]

Therefore, according to the invention of claim 1, by taking the above-mentioned means, the branch line LAN is provided in the normal connection mode.
The data of the primary ring transmission line of is taken in by the main part of the main LAN station under the notification from the branch LAN interface and sent as it is to the primary ring transmission line of the main LAN, and the data of the secondary ring transmission line of the branch LAN is Bypassing in the branch line LAN interface and returning to the secondary ring transmission line of the branch line LAN, only one channel is required for each branch line LAN when connecting the repeater of the branch line LAN. Can be significantly reduced, which can significantly improve the transmission efficiency.

According to the second aspect of the present invention, when the branch line LAN is started up, the fact that the branch line LAN connected to itself is connected using the connection control channel of the main line LAN is connected to another main line station through the main line LAN. When transmitting and receiving a connection notification of another branch line LAN connected to itself from another trunk line station, primary ring data of the trunk line LAN and the primary ring data of the branch line LAN are respectively received under permission of connection control. And main line LAN
To the primary ring transmission line of the main line and the secondary ring data of the trunk line LAN and the branch line LAN are respectively transmitted using the connection control channel. Therefore, the branch line can be effectively used while using the connection control channel of the trunk line LAN. LAN startup can be established and branch line LA thereafter
Since the repeater of N data can be performed in the same manner as the invention corresponding to claim 1, the number of channels can be greatly reduced in the same manner.
This can significantly improve the transmission efficiency.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of a main station according to the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an example of the construction of a LAN system including a main station according to the present invention. In the figure, 1 is a trunk LAN in which a plurality of trunk stations S1 to S4 are serially connected by a duplex ring transmission line.
Is. As described above, these duplicated ring transmission lines are composed of the primary ring transmission line and the secondary ring transmission line, and data flow in the opposite directions. Since, for example, one or a plurality of high speed branch lines LAN are connected to the trunk LAN 1, a high speed ring type L
It constitutes AN.

On the other hand, the branch line LAN 2 (or 3) also includes one or more branch line stations S5, S6 (or S) including a main line station by a duplicated ring transmission line.
7 and S8) are serially connected and are connected so as to physically form one ring when viewed from the trunk LAN 1.

Of these duplex ring transmission lines of the branch lines LAN2 and LAN3, one ring transmission line is called a primary ring and the other ring transmission line is called a secondary ring.
Normally, the primary ring transmission line is used for data communication, while the secondary ring transmission line is configured to monitor the disconnection of the transmission line by transmitting a synchronization symbol or the like without transmitting data. These branch line stations S5, ... Have a function of controlling the connection of the branch lines LAN2, 3 as well as the connection control of a low-speed LAN (not shown) connected to the lower order and the connection of the circuit switching type terminal equipment.

The main line stations S1 and S2 are shown in FIG.
As shown in FIG. 2, a trunk LAN station basic unit 10 that controls transmission in the trunk LAN 1 and connection control of one or more branch LANs, and a branch LAN interface 20 that controls the connection of the branch LAN 1 between the trunk LAN 1 and the branch LAN 2 It consists of and.

This main line LAN station basic section 10
In addition to the trunk line LAN receivers 11 and 14 and the trunk line LAN transmitters 12 and 13, it transmits the data from the branch line LAN2 if there is data, and transmits the data received from the trunk line LAN1 if there is no data from the branch line LAN2. A primary ring data transmission / reception control unit 15 and a secondary ring data transmission / reception control unit 16 are provided, and a trunk LAN basic control unit 17 and an internal bus interface 1 are provided.
8 and 19 are provided.

The main line LAN basic control unit 17 has a main line L.
The AN1 is monitored, the transmission line is controlled, the connection of the branch LAN interface 20 is controlled, and the like. The internal bus interfaces 18 and 19 perform data transmission / reception between the data received from the data internal buses 1B and 1C and the transmission / reception control units 15 and 16 based on the selection data from the trunk LAN basic control unit 17. It has a function. A control bus 1A is used for communication of control information between the trunk LAN basic controller 17 and the branch LAN connection controller 21 of the branch LAN interface 20.

On the other hand, the branch LAN interface 20 is
In addition to the branch line LAN connection control unit 21, internal bus interfaces 22 and 23 and branch line LAN transmission / reception units 24 to 27 are provided. This internal bus interface 22, 23
Transmits the data received by the branch line LAN transmission / reception units 25 and 27 to the other party designated by the branch line LAN connection control unit 21, and the data received from the data internal buses 1B and 1C to the trunk line LAN basic It is transmitted to the other party designated by the control unit 17. Further, the branch line LAN transmission / reception units 24 to 27 transmit the data received from the branch line LAN2 to the connection control unit 21 and the internal bus interfaces 22 and 23, and the data received from the internal bus interfaces 22 and 23 to the branch line LAN2. It has a function to send.

In the figure, L1 and L1 'are trunk LAN primary ring transmission lines, L2 and L2' are trunk LAN secondary ring transmission lines, L3 and L3 'are branch line LAN primary ring transmission lines, and L4 and L4' are. It is a branch LAN secondary ring transmission line. Next, the operation of the transmission system configured as above will be described with reference to FIGS. 1 and 2.

First, the premise of the operation in the main line stations S1 and S2 will be described. Now, a plurality of main line stations S are provided on the main line LAN 1 formed in a double ring shape.
1 to S4 are connected, of which the main station S1,
In S2, data communication is normally performed only on one ring 2
Branch lines LAN2 and LAN3 having a redundant ring configuration are connected.
At this time, the trunk line stations S1 and S2 are repeater-connected to the branch lines LAN2 and 3 which are performing data communication.

In the branch line LAN interface 20 in the main line station S1, only the transmission lines L3 and L3 'of the branch line LAN2 are used for data transmission / reception,
On one of the transmission lines L4 and L4 ', only the presence or absence of disconnection of the transmission line is monitored, and no communication data is flowing. next,
The operation of the main station S1 will be specifically described. This main station S1 operates under several modes. (1) Normal connection mode ... This is a mode in which the branch LAN transmits and receives data using the primary ring.

First, the primary ring transmission line L3-L3 'and the secondary ring transmission line L4- of the branch line LAN2.
The data of L4 'is received by the branch LAN transmission / reception units 27 and 25. These transmitting / receiving units 27 and 25 perform clock extraction and data synchronization, and send the received data to the internal bus interfaces 22 and 23, while the branch line LA is used.
The connection status with the branch LAN and the received data are transmitted to the N connection control unit 21.

Here, the branch line LAN connection control unit 21 controls the internal bus interface 22 to transmit data to the data internal bus 1B, and also the trunk line L.
The AN basic control unit 17 is notified that the data of the branch line LAN will be transmitted. Therefore, the internal bus interface 22 converts the received data into parallel data and transmits it to the trunk LAN via the data internal bus 18 and the primary ring data transmission / reception control unit 15. On the other hand, the main line LA
The primary ring data of N is transmitted from the branch LAN transmission / reception unit 2 through the internal bus interface 22 under the notification from the trunk LAN basic control unit 17 to the branch LAN connection control unit 21.
4 and is sent to the primary ring transmission line L3 of the branch line LAN.

Next, with respect to the data received by the branch line LAN transmitting / receiving unit 25, the branch line LAN connection control unit 25 issues an instruction to bypass by the internal bus interface 23, whereby the secondary ring transmission line of the branch line LAN is transmitted. Data of the transmitter / receiver 25-internal bus interface 2
The secondary ring transmission line L4 of the branch line LAN is returned through the bypass line of the 3-branch line LAN transmitting / receiving unit 26.

As described above, only the data of the primary ring of the branch line LAN is transmitted to the trunk line LAN, and the branch line L
The AN2 and the branch line LAN3 are normally connected. On the other hand, the data on the secondary ring is bypassed because it is only monitored by the sync symbol. (2) Connection control mode ... This is a branch line station S
In this mode, power is supplied to S5 and S6 and the branch line LAN2 is activated.

Now, when the power supply to the branch line stations S5 and S6 is turned on, the branch line LAN transmission / reception units 25 and 27 detect that the branch line LAN2 is connected and notify the branch line LAN connection unit 21. Here, the branch line LAN connection unit 21 notifies the main line LAN basic control unit 17 that connection control is started. That is, the branch line LAN2 connected to itself
After the connection is confirmed, it has a branch line LAN connection control function that outputs a notification to the effect that connection control is started.

Therefore, the trunk line LAN basic control unit 17 broadcasts to all stations that the branch line LAN connected to itself is connected using one connection control channel which is a fixed channel in the trunk line LAN. Notice. After that, when the trunk line LAN basic control unit 17 receives the connection notification of the branch line LAN3 from the other trunk line station S2, the branch line L3 to be connected to the branch line LAN3.
When AN2 exists, the branch line LAN connection control unit 21 is notified of the start of connection control. Further, the trunk line LAN basic control unit 17 also notifies the branch line LAN connection control unit 21 of permission of connection control even when receiving a notification from the trunk line LAN that it should be connected to its own connection branch line LAN.

Here, the branch line LAN connection control unit 21 notifies the internal bus interface 22 when it receives a connection control start notification of the other branch line LAN 3 or when it receives a connection permission notification from the trunk line LAN basic control unit 17. , Data from the branch line LAN3 sent from the data internal bus 1B through the internal bus interface 22 to the branch line LAN
Transmission line control is performed so that the data is transmitted to the transmission / reception unit 24, while the data of the ring transmission line L3 'of the branch line LAN2 is transmitted to the internal bus interface 18 through the internal bus interface 22 and the internal data bus 1B.

Further, the branch line LAN connection control section 21 transmits the data from the internal data bus 1C sent using the connection control channel to the branch line LAN transmission / reception section 26,
On the other hand, transmission line control is performed such that data from the ring transmission line L4 'of the branch line LAN2 is transmitted from the transmission / reception unit 25 onto the main line LAN using the connection control channel of the internal data bus 1C.

Therefore, in this connection control mode, the branch lines LAN2,
By connecting the primary ring and the secondary ring of No. 3, it is possible to establish the operation of each branch LAN, and even if the number of channels is reduced in the normal connection mode of (1) above, the branch LAN can be started without any problem. It can be performed. (3) Transition mode from connection control mode to normal connection mode

When the operation for establishing the ring is completed, the branch line LA
The N transmission / reception units 25 and 27 notify the branch line LAN connection control unit 21 to that effect. As a result, the branch LAN interface 20 shifts to mode 1. The connection control channel becomes a monitoring / maintenance channel in the trunk LAN when the connection control of the branch LAN is completed. (4) In branch LAN error mode

Branch line LAN, for example, two stations S5
When S6 or the ring transmission line is abnormal, the operation is divided into the following two modes. When these branch LANs are abnormal, first of all,
The loopback function works at the branch line LAN station so as to disconnect the abnormal part.

Standing on it, in the first mode, both the primary ring and the secondary ring of the branch line LAN2 are connected to the trunk line LAN1. In this case,
It is necessary to reserve a channel for connecting the secondary ring, but multiple branch lines LA connected to the trunk LAN
Since N is hardly in an abnormal state at the same time, it is only necessary to prepare the minimum number of channels required for this operation mode, for example, one channel. This operation mode is effective when extremely high reliability is required and communication with other rings is almost occupied.

Next, in the second mode, both the primary ring and the secondary ring of the branch LAN, the internal interface 22 of the branch LAN interface 20,
By bypassing at 23, both rings are the main line LA
It is a mode in which N is not connected. This mode is performed when most of the communications are intra-ring communications. Since the communication path in the branch LAN is secured, communication between terminals including the loopback function is possible.

Therefore, according to the configuration of the above embodiment, the received data from the branch LAN, for example, the primary ring of 2 is always transmitted to the trunk LAN 1 and the secondary data is transmitted.
The data received from the ring is bypassed and transmitted to the LAN 2 as it is. When power is supplied to a branch line LAN, for example, a branch line station of 2, and the ring of the branch line LAN2 rises, one fixed channel in the main line LAN1, that is, a connection control channel is used to transfer the data of the secondary ring of the branch line LAN2. When the transmission is completed and the connection control of the connection control channel is completed, the channel becomes a monitoring / maintenance channel in the trunk LAN 1.

The branch line LAN connection control can be started only when the branch line LAN connection control unit 21 of the main line station permits. On the other hand, the main LAN 1 channel to be connected at the time of abnormality is prepared in the minimum necessary amount, and the secondary ring is connected only at the time of abnormality.

Therefore, by having such a function, when the branch line LAN of the duplicated ring is repeater-connected at the main line station, one channel is conventionally required for each branch line LAN, and one channel is conventionally provided. It is possible to halve the number of channels as compared with the above, and it is possible to significantly improve the usage efficiency of the trunk LAN. In addition, branch line LAN
At the time of start-up, the start-up establishment operation can be executed by using the fixed connection control channel that has been present in the past.

Further, when the branch line LAN is abnormal, it is rare that a plurality of branch line LANs become abnormal at the same time, and if one dedicated channel is added to the branch line LAN, the minimum necessary channel is used for the main line LAN. The secondary ring can be connected without reducing reliability. The present invention can be variously modified and implemented without departing from the scope of the invention.

[0045]

As described above, according to the present invention, the branch line LAN of the duplex ring can be repeater-connected by using half the channel as compared with the conventional one, and the trunk line LAN can be connected.
It is possible to significantly improve the use efficiency of.

Since the branch line LAN is established by effectively utilizing the connection control channel, the branch line LAN is established and the subsequent data communication is performed by using almost half the channels as compared with the conventional one. be able to.

[Brief description of drawings]

FIG. 1 is a block diagram of a LAN system to which a trunk station according to the present invention is applied.

FIG. 2 is a configuration diagram showing an embodiment of a mainline station according to the present invention.

[Explanation of symbols]

S1 to S4 ... Trunk line station, S5 to S8 ... Branch line station, L1, L1 ', L3, L3' ... Primary
Ring transmission line, L2, L2 ', L4, L4' ... Secondary ring transmission line, 1 ... Trunk line LAN, 1A ... Control bus, 1B, 1C ... Data internal bus, 2, 3 ... Branch line LA
N, 10 ... Trunk line LAN station basic unit, 15 ... Primary ring data transmission / reception control unit, 16 ... Secondary ring data transmission / reception control unit, 17 ... Trunk line LAN basic control unit, 18, 19 ... Internal bus interface, 20 ... Branch line LAN Interface, 21 ... Branch line LAN connection control unit, 22, 23 ... Internal bus interface, 24-27
... Branch line LAN transceiver.

Claims (2)

[Claims] 1. A communication data and a transmission which are mounted on a trunk LAN (local area network) having a primary ring transmission line and a secondary ring transmission line which respectively transfer communication data in opposite directions and which are opposite to each other. Branch line L having a primary ring transmission line and a secondary ring transmission line for transferring route monitoring data
In a mainline station to which an AN is connected, a mainline LAN station basic unit for receiving communication data of a primary ring transmission line and a secondary ring transmission line of the mainline LAN and transmitting the communication data to respective ring transmission lines of the mainline LAN. In the normal connection mode, when the communication data of the primary ring transmission line of the branch line LAN is received, the trunk line LAN
Under the permission of the station basic unit, the communication data is sent to the main line LAN via the main line LAN station basic unit.
When the transmission line monitoring data of the secondary ring transmission line of the branch line LAN is received, the branch line LA is internally bypassed.
A trunk line station comprising a branch LAN interface for returning to N secondary ring transmission lines. 2. A communication system and transmission line monitoring data, which are mounted on a trunk LAN having a primary ring transmission line and a secondary ring transmission line that respectively transfer communication data in opposite directions, and in opposite directions. In a trunk station to which a branch LAN having a primary ring transmission path and a secondary ring transmission path to be transferred is connected, the trunk line receives the communication data of the primary ring transmission path and the secondary ring transmission path of the trunk LAN When the communication data of the primary and secondary transmission / reception control means for transmitting to the corresponding ring transmission lines of the LAN and the normal connection mode is received and the communication data of the primary ring transmission line of the branch line LAN is received, the permission of the basic section of the trunk LAN station is given. Below the communication data is the main LAN Internally when the data is transmitted to the primary ring transmission line of the trunk LAN via the primary transmission / reception control means of the station basic unit and the transmission line monitoring data of the secondary ring transmission line of the branch LAN is received. First branch LAN connection control means for bypassing and returning to the secondary ring transmission line of the branch LAN, and when the branch LAN ring starts up, after confirming the connection of the branch LAN connected to itself, start connection control Second branch line LAN connection control means for outputting a notice to that effect, and a branch line LAN which is connected to itself by using the connection control channel of the main line LAN when notified from the second branch line LAN connection control means A main trunk LAN basic control means for transmitting to the other trunk station through the trunk LAN, and the other trunk. When receiving the connection notification of the other branch LAN connected from the station to its own, the output permission for connection control 2
Primary trunk data of the trunk line LAN and the primary ring data of the trunk line LAN, respectively, on the basis of the connection control start permission from the trunk line LAN basic control unit of the second main line LAN basic control unit. It is transmitted to a ring transmission line, and the trunk LAN is used.
And a transmission line control means for transmitting the secondary ring data of the branch line LAN by using the connection control channel, respectively.