JP2733950B2 - Token ring controller - Google Patents

Description

Detailed Description of the Invention [Table of Contents] Overview Industrial application field Conventional technology and problems to be solved by the invention Means to solve the problem Action Embodiment Effect of the invention [Overview] Multiple local area networks (LAN) Token Ring using token passing method as a transit bridge and other local area network (LAN)
In a network system that performs communication by relaying only information frames received from a network device, a plurality of token frames are generated on a relay token ring and each transmitting node To prevent the transmission from being disturbed by the other transmitting node, and to relay information from another local area network (LAN) to each node in the token ring constituting the relay bridge. Means for retaining the source address (SA) field in the frame, and transmitting the relayed information frame to the token ring, and determining whether the returned information frame is the relay information frame transmitted by itself. Means for comparing information frames from the other local area network (LAN). The contents of the source address (SA) field of the information frame transmitted and returned on the token ring are compared with the contents of the source address (SA) field in the held relay information frame. Is configured to identify the transmitted relay information frame.

[Industrial applications]

The present invention relates to a plurality of local area networks (LAs).
N), a token ring using a token passing method is used as a relay bridge, and the network system is configured to perform communication by relaying only information frames received from another local area network (LAN). Related to a token ring control device.

In recent years, local area networks (LANs) are various types of local area networks (LAs) depending on the application.
N) has been developed, but it can be broadly divided between a network connecting terminal devices such as workstations (WS) at a relatively low speed and a host using a token passing method at a relatively high speed. There is a token ring for communication, and a method of relaying between local area networks (LANs) has been considered.

In this case, in the method of relaying between the local area networks (LAN) connecting the workstations (WS) and the like, only the hosts of the respective networks can be used, but they are used for the above-mentioned inter-host communication. Considering that a high-speed token ring is used as a relay local area network (LAN) to connect another local area network (LAN), a terminal connected to the other local area network (LAN), for example, a workstation Since the (WS) can communicate with any host on the token ring, a network system that connects another local area network (LAN) using the token ring as a relay bridge is required. .

[Problems to be solved by conventional technology and invention]

FIG. 2 is a diagram for explaining a basic configuration of a token ring. (A) shows an example of a basic configuration, (b) shows a format of a node address, (c) shows a format of a token frame, d) shows the format of the information frame.

In the token ring 1 shown in FIG.
The communication between the nodes 2 corresponds to the information frame 35 shown in FIG.
Enter the destination node address in the "DA" field of "SA".
This has been done by specifying the source node address in the field.

Each node address is set as follows.

That is, this address assignment is performed for each system,
At the time of system configuration, a node address is uniquely assigned to each node 2, and at the time of system expansion, management is performed so as not to overlap with an already set address.

The node address of each node 2 is configured in the format shown in FIG. 3B, and the element number portion in the node address is set to a different address value for each node 2 in the same ring 1. I was

In the token ring 1 using the token passing method, the following two types of frames are used.

One of them is a token frame 30, which has the format shown in FIG. In the figure, “SD” indicates the start code of the frame, “AC” indicates the control field, and “ED” indicates the end code of the frame.

The second is an information frame 35, which has the format shown in FIG. In the figure, “FC” indicates a frame type, “DA” indicates a destination address of the frame, “SA” indicates a source address of the frame,
“I” indicates an information field, “FCS” indicates an error detection code of a frame, and “FS” indicates a state of ring 1. Note that the meanings of “SD”, “AC”, and “ED” are the same as in the case of the token frame 30 described above.

Next, referring to FIG. 2 (a), the operation of the conventional token-passing token ring will be described with reference to FIG. 3 showing a configuration example of a conventional node.

In token ring 1 of the token passing method, a control frame called the token frame (T) 30 sequentially circulates on the token ring 1 (indicated by "" in FIG. 2A), and the information frame 35 is The node 2 that wants to transmit detects the start code (SD) of the token frame (T) 30 and activates the main control unit (CTL) 10 under the control of the control field of the token frame (T) 30. By detecting (AC) by the token detector 5, the transmission of the information frame 35 can be started only while the token frame (T) 30 is being captured.

Specifically, the information frame 35 set in the memory 9 is transferred to the data buffer (D) under the control of the main control unit (CTRL) 10 which has recognized the capture of the token frame (T) 30.
B) Send to ring 1 via 20.

After the transmission of the information frame 35, the information frame 35
Returns to the source node 2 one week after the token ring 1, the “AC”, “DA”, and “SA” sections of the information frame 35 are stored in the header storage register 3 of the node 2. The source node address register (MA) 4 set in the node 2 and the source address (S) of the information frame 35 set in the header storage register 3 are set.
A) When the comparison circuit (C2) 41 detects 3c, the transmission of the information frame 35 to the ring 1 is suppressed by controlling the suppression gate circuit 22, and the token frame (T) set in the memory 9 is suppressed. By sending 30 to the token ring 1 via the data buffer (DB) 20, the token frame (T)
30 operates again to cycle on token ring 1.

In the node 2 receiving the information frame 35, the destination address (DA) 3b set in the header storage register 3 and the own node address register (M
A) 4 is compared with the comparison circuit (C1) 40 to recognize the information frame 35 for the own node 2, and the “I” portion and the like are transferred to the memory 9 via the data buffer (DB) 20 and the copy circuit 21. And the information frame 35 is sent out again on the token ring 1.

Thus, when the information frame 35 is not transmitted on the token ring 1, it means that only one token frame (T) 30 is circulating on the ring.

FIG. 4 is a diagram showing a configuration example of a relay bridge using a token ring. When the above-described conventional token ring 1 is used for the relay bridge, the following problem may occur.

In the figure, LAN (1) and LAN (2) indicate other local area networks (hereinafter, referred to as LAN). LAN (3) indicates the token ring.
Indicates a general node 2, and indicates a node 2 set for a relay bridge.

Now, a case where the device A transmits the information frame 35 to the device B will be described as an example.

LAN (1) and LAN (2) are different from each other
LAN address is set, general nodes ,,
It is also assumed that the nodes 2 to 2 set for the relay bridge are also set such that the element numbers are unique within each LAN system. Further, when the LAN address of the information frame 35 passing through the own node is different from the LAN address of the own node, the nodes 2 to 2 receive the information frame as a relay bridge function and
It has a function to deliver to N.

The procedure for transmitting the information frame 35 from the device A to the device B will be described below.

First, the device A sets the node address of the node 2 connected to the LAN (2) as the transmission destination address in the “DA” field in the information frame 35, and sets the own node as the transmission source address in the “SA” field. Set the address and send.

The node 2 compares the "LAN address" in the "DA" field of the information frame 35 with the "LAN address" of its own node by the comparison circuit (C1) 40, recognizes a mismatch, and temporarily stores the information frame 35 in the memory. 9 and passes it from the memory 9 to the node 2 of the LAN (3) (relay bridge) via the inter-LAN buffer 11.

The node 2 constitutes a node of the token ring 1 and transmits the information frame 35 once received and temporarily stored in the memory 9 onto the token ring 1. ) To capture 30.

Node 2 that has captured the token frame (T) 30
Transmits the information frame 35 from the memory 9 to the ring 1 via the data buffer (DB) 20.

The node 2 compares the “LAN address” of the “DA” field of the information frame 35 passing therethrough with the “LAN address” of the own node by the comparison circuit (C1) 40, recognizes a mismatch, and recognizes the information frame 35. Is received by the memory 9 and transferred from the memory 9 to the node of the LAN (2) via the inter-LAN buffer 11.

The node 2 of the LAN (2) receives the received information frame 3
5 is transmitted to the LAN (2) to which the own node is connected via the memory 9 and the data buffer (DB) 20.

In the LAN (2), at the node through which the information frame 35 passes, the "DA" field of the information frame 35 is compared with its own node address (MA) 4 by the comparison circuit (C1) 40. Recognizing the information as information for the node, the information frame 35 is transferred to the memory 9 via the copy circuit 21.
And notifies the device B by a route not shown.

On the other hand, node 2 in the token ring 1
Start code (SD) of the information frame 35 returned by one round
Is detected by the data buffer (DB) 20, the suppression gate circuit 22 is controlled immediately, and the information frame 35 transmitted by itself is
The returned information frame 35 is deleted from the ring 1 without confirming whether or not the token frame (T) 30 set in the memory 9 is stored in the data buffer (D).
B) Send out onto token ring 1 via 20.

However, this method works effectively as described above only when the token ring 1 is normal, but in the original token ring 1, the returned information frame 35
When the “SA” field 3c is compared with the source node address register (MA) 4 of the transmission source by the comparison circuit (C2) 41,
There is a problem in that the token ring 1 does not match and the originally normal token ring 1 looks abnormal.

Therefore, as described above, the transmission source node 2
A method of transmitting the token frame (T) 30 onto the token ring 1 without comparing the “SA” field 3c of the returned information frame 35 with the source node address register (MA) 4 of the transmission source is adopted. If the token ring 1 is abnormal and another information frame is generated, the token frame (T) 30 is also transmitted by the other information frame. When the token frame (T) 30 is generated, a plurality of nodes 2 may simultaneously capture the token frame (T) 30 and transmit the information frame 35 at the same time. Each of the transmitting nodes 2 has a problem in that the transmission may be hindered by the other transmitting nodes 2.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional disadvantages, and has an object to provide a relay local area network (LAN) in a network system that relays a plurality of local area networks (LAN)
In the case of the token ring of the token passing method, a node that relays only information frames received from another local area network (LAN) provides a token ring control device that does not generate a plurality of token frames. It is the purpose.

[Means for solving the problem]

The above problem is solved by a token ring control device configured as follows.

An information frame received from a local area network (LAN) is transferred between a plurality of local area networks (LANs) onto a token ring that constitutes a network system that performs communication using a token ring using a token passing method as a relay bridge. In the token ring control device to be relayed, holding means for holding the contents of a source address (SA) field in an information frame received from the local area network (LAN) ｛source address register (TX
SA) $ 6, the contents of the source address (SA) field in the information frame received from the token ring, and the source address of the information frame received from the local area network (LAN) held in the holding means 6 SA) a comparing means (C3) 42 for comparing the contents of the field with the contents of the token ring based on the comparison result of the comparing means (C3) 42; An identification means (inhibition gate circuit) 22 for identifying whether the information frame is a relayed information frame is provided.

[Action]

That is, according to the present invention, when the token ring is used as a relay bridge, a means for holding the “SA” field in the information frame passed from another LAN in the transmitting node is provided, and When transmitting the passed information frame, the "SA" field is temporarily held, and the relay information frame is sent out on the token ring.

Then, the “SA” field of the information frame returned by making a round around the token ring and the “S”
By comparing the information frame with the contents of the "A" field, it is determined whether the information frame is a transmitted information frame.

If the comparison results in a match,
By erasing the received information frame or the information frame being received from the token ring as the information frame transmitted by the node, and transmitting the token frame instead, a single token frame is again placed on the token ring. To make a round.

If the comparison results in a mismatch, the token ring is recognized as being abnormal, the received information frame or the information frame being received is deleted from the token ring, and the token frame is transmitted. Instead, the token ring recovery process is performed.

Therefore, even when a token passing-type token ring is used as a relay bridge, only a single token frame circulates on the token ring, and the token ring can be normally functioned.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, in which a source address register (TXSA) 6, a comparison circuit (C3) 42, and a coincidence output signal of the comparison circuit (C3) 42 are used. The suppression gate circuit (corresponding to the identification means in the claims) 22 for erasing the information frame 35 on the token ring 1 and transmitting the token frame instead is the means necessary to carry out the present invention. Note that the same reference numerals indicate the same object throughout the drawings.

Hereinafter, the token ring control device of the present invention will be described with reference to a configuration example of a relay bridge using the token ring of FIG.

Even if the present invention is implemented, the LAN (1) can be
LAN for transmitting information frame 35 to device B in (2)
The operations at the relay node of (1), the relay node of the LAN (2), and the node 2 on the token ring 1 do not change in particular, and are omitted, and the transfer operation at the node 2 on the token ring 1 is omitted here. The explanation will be focused on.

First, in the node 2 on the token ring 1 functioning as a transit bridge, the contents of the "SA" field of the information frame 35 passed from the transit node 2 of the LAN (2) are transmitted to the source address register (TXSA). 6 and the information frame 35 is temporarily stored in the memory 9.

Here, the node 2 receives the received information frame.
In order to transmit 35 on the token ring 1, a token frame (T) 30 circulating on the token ring 1 is captured.

Node 2 that has captured the token frame (T) 30
The relay information frame 35 stored in the memory 9 is taken out and transmitted to the token ring 1 via the data buffer (DB) 20.

When the node 2 receives the information frame 35 circulating on the token ring 1, the node 2 sets the contents of the “SA” field of the information frame 35 set in the (SA) section 3c of the header storage register 3 described above. The comparison circuit (C3) 42 compares the source address “SA” stored when the information frame 35 was received with the source address “SA”, and if the addresses match, the received information frame is transmitted to the transmitted relay information frame 35. And recognize
By controlling the suppression gate circuit 22 with the coincidence signal, the received relay information frame 35 or the currently received relay information frame 35 is controlled.
Is erased from the token ring 1, the token frame is taken out from the memory 9, and the token frame is transmitted to the token ring 1 via the data buffer (DB) 20.

As a result, a single token frame (T) 30 circulates again on the token ring 1.

If a mismatch signal is obtained in the receiving operation of the above relay information frame 35, it is recognized that the token ring 1 is abnormal, and the received relay information frame 35 or the relay information frame 35 being received is subjected to the token ring 1. 1 to suppress the transmission of the token frame (T) 30 and to start the recovery processing of the token ring 1.

In the recovery process, for example, after all information on the token ring 1 is cleared, only one token frame (T) 30 is generated, and the transmission of the information frame 35 is awaited.

As described above, according to the present invention, a token passing type token ring is used as a relay bridge between a plurality of local area networks (LANs), and communication is performed by relaying only information frames received from other local area networks (LANs). In the token ring control device configuring the network system in the network system to be performed, "S" in the information frame passed from another LAN is used.
A means for holding the `` A '' field in the transmitting node is provided, and when transmitting the relay information frame to the token ring, once transmitting the information frame on the token ring while holding the `` SA '' field, It is characterized in that the "SA" field of the returned information frame is compared with the content of the "SA" held to identify whether or not the information frame was transmitted by itself.

〔The invention's effect〕

As described above in detail, the token ring control device of the present invention provides the node in the token ring used as a transit bridge to the source in the information frame relayed from another local area network (LAN). Means for retaining an address (SA) field, means for transmitting the relayed information frame to the token ring, and comparing whether or not the returned information frame is the relay information frame transmitted by itself. And identifying means (suppression gate circuit) for identifying whether the information frame received from the token ring is an information frame received and relayed from the local area network based on a comparison result by the comparing means. Sends an information frame from another local area network (LAN) onto the token ring and returns The content of the source address (SA) field of the information frame is compared with the content of the source address (SA) field in the held relay information frame to identify the relay information frame transmitted by itself. Therefore, even when a token ring of the token passing method is used as a relay bridge, only a single token frame circulates on the token ring, and the token ring can function normally. There is.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a diagram for explaining a basic configuration of a token ring, FIG. 3 is a diagram showing a configuration example of a conventional node, FIG. Is a diagram showing a configuration example of a relay bridge using token ring. In the drawing, 1 is a token ring or simply a ring, 2 is a node, 20 is a data buffer (DB), 21 is a copy circuit, 22 is a suppression gate circuit, 3 is a header storage register, 3a is an “AC” part, 3b Is the "DA" part, 3c is the "SA" part, 4 is the own node address register (MA), 40 to 42 are the comparison circuits (C1 to C3), 5 is the token detector, 6 is the source address register (TXSA) , 9 is a memory, 10 is a main controller, 11 is a buffer between LANs, 30 is a token frame (T), 35 is an information frame, DA is a destination address of a frame, SA is a source address of a frame, and AC is a control field. And, respectively.

Claims (1)

(57) [Claims] An information frame received from a local area network is relayed between a plurality of local area networks onto a token ring which constitutes a network system for performing communication using a token ring using a token passing method as a relay bridge. Holding means for holding the contents of a source address field in an information frame received from the local area network; and holding and holding the contents of a source address field in an information frame received from the token ring. Comparing means for comparing the content of the source address field of the information frame received from the local area network held by the means with the information frame received from the token ring based on the comparison result of the comparing means. Identifying means for identifying whether information frames relayed received from the local area network, a token ring controller characterized by comprising.