JPH02239742A - Frame strip system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] Conventionally, the present invention relates to a token ring control method in a network system in which communication is performed between multiple local area networks by connecting a token ring using a token bashing method as a relay bridge. In order to solve the problem that the relay information frame that has gone around the token ring is not deleted every time communication is performed via the relay bridge, and unnecessary information frames are accumulated on the ring, each node in the token ring means for retaining the address of the source of the information frame relayed to;
A means is provided for comparing the returned information frame with the content of the source address holding means to determine whether it is the relay information frame transmitted by itself.

[Industrial field of application] The present invention connects a plurality of local area networks (hereinafter also simply referred to as rLANJ) using a token ring using a token passing method as a relay bridge, thereby enabling communication. This paper relates to a token ring control method in a network system.

[Prior Art] FIG. 2 shows a diagram explaining the basic configuration of a token ring, and FIG. 3 shows an example of the format of an information frame transmitted within a network.

In the example of the system shown in FIG. 2, each node 11 to 14 (
Networks indicated by A to D) (LAN (1)
) and nodes 10, 20, 3 configured in a ring format.
0 and node 21 (E) (L
A N (2)) and each node 31 to 34 (F
-I) network (LAN (3
)) is connected.

Further, in the configuration example of the information frame shown in FIG. 3, as shown in the figure, the following signal fields are used as its constituent elements.

PA = Brian, SD = Start Delimiter, FC = Frame Control, DA = Destination Address, S81 Source Address,
INFO=Information Field, FCS=Frame Check Sequence, ED=End of Frame Delimiter, FS=Frame Status.

In a network system that uses a conventional single-token method for communication using a token ring as a relay bridge, the relay information frame that goes around the ring and returns is erased without confirming whether it is the information frame that was sent by itself. Was.

However, in the multiple token method, multiple information frames can be sent, so the SA field indicating the source address of the returned information frame and the own address (
MA), and only if they match, the frame is erased. In this method, other L A N (
From 1) to multiple token system L A N (2)
When communication is made to LAN (3) via the relay bridge of LAN (3), the SA field of the information frame to be relayed remains the originating address SA of the source node of the original LAN (1). If this continues, this frame will be LA.
When it returns after going around N (2), it does not match the node address of the relay bridge.

[Problems to be Solved by the Invention] Therefore, each time communication is performed via the relay bridge (LAN (2)), the relay information frame that has gone around the ring is not erased, and unnecessary relay information frames are sent to the ring. This caused the problem that the liquid was accumulated on the top.

An object of the present invention is to appropriately remove an information frame relayed via a relay bridge at a node in the relay bridge when the information frame goes around the ring.

[Means for Solving the Problems] According to the present invention, the above objects are achieved by the means described in the claims.

That is, the present invention provides a network system in which a plurality of local area networks are connected using a token ring using a multiple token passing method as a relay bridge, and each node in the token ring constituting the relay bridge is connected to the network system. The system includes a means for retaining the source address in an information frame relayed from another local area network, a means for transmitting the relayed information frame to the above-mentioned token ring, and a means for transmitting the information frame that has gone around the token ring and returned. , a frame strip that uses the contents of the source address holding means to compare whether or not it is a relay information frame transmitted by itself, and removes the relay information frame if it is a relay information frame transmitted by itself. It is a method.

[Operation] In a network system in which multiple LANs communicate by connecting a token ring using a token bashing method as a relay bridge, each node in the token ring receives information relayed from other LANs. A means for holding a plurality of SA fields indicating the source address in a frame, such as a multi-stage parallel data shift register, is used, and the relayed information frame is transmitted to the token ring and sent around the ring and back. The SA field in the received information frame and the contents of the shift register are compared to see if it is the relay information frame sent by itself, and if they match, it is removed as the relay information frame sent by itself. .

[Embodiment] FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, in which a token ring L A N (2
) is installed at each node 10, 20, 30 within. In the figure, 1 to 4 are n-stage parallel data shift registers (registers a % n ) that receive multiplication from other LANs and hold the SA field in the information frame relayed by the token ring; 5 to 4; Reference numeral 8 represents an originating address comparison device (c) which transmits a relayed information frame (relay information frame) to the token ring and compares whether the returned information frame is the relay information frame transmitted by itself. .

The address comparator C compares the values in the shift registers a to n with the SA field of the relay frame that has returned after going around the ring, and if they match, a match signal S is output. By outputting this coincidence signal S, the relay information frame is removed.

An example of the operation in the case of the network system shown in FIG. 2 will be described below.

An information frame emitted from node 12 (address A) in L A N (1) passes through node 10 and is transferred to LAN (
2), when the relay information frame is transmitted as a relay information frame, the SA field (address A) in the relay information frame is stored in register a in the node 10.

Next, before releasing the token, if there is a request to relay an information frame from node 14 (address B) in LAN (1) to node 10, the address A is shifted from register a to register b. , address B is stored in register a.

In this way, n SAs of information frames relayed at the closest time are stored in shift registers a to n.

When the relayed information frame goes around the LAN (2) and returns, the SA field in this information frame is compared with the source address stored in shift registers a to n, and if they match, the frame is is removed. Therefore, node 10 can transmit no more than n frames before releasing the token. Also, here, if the maximum number of information frames that can be transmitted by grabbing a token is m, then m≦n
Must.

[Effects of the Invention] As explained above, according to the present invention, unnecessary information frames are no longer circulated on the ring, which greatly contributes to improving the reliability of the network system.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the configuration of an embodiment of the present invention, FIG. 2 is a diagram explaining the basic configuration of a token ring, and FIG. 3 is a diagram showing an example of the configuration of an information frame. 1 to 4...N stage shift registers a to n, 5
~8... Originating address comparison device (C), 10
, 20, 30... Each node in the token ring, 11 to 13, 2L 31 to 34... Each node in the network system

Claims (1)

[Claims] In a network system in which a plurality of local area networks are connected as a relay bridge using a token ring using a multiple token passing method, each node in the token ring constituting the relay bridge is provided with the following: means for holding one or more source addresses in information frames relayed from other local area networks, and means for transmitting the relayed information frames to the token ring and returning after going around the token ring. means for comparing whether or not the transmitted information frame is a relay information frame transmitted by oneself, using the contents of the source address holding means, and in the case of a relay information frame transmitted by oneself, the relay information frame is removed. The frame strip method is characterized by: