JPH04250740A - Communication network control device - 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication network control device applicable to multimedia communication, typified by a local area network (LAN).

0002

2. Description of the Related Art There are various types of communication networks of this type, one of which is a multi-channel lattice communication network based on the analogy of biological nerve cells.
It is shown in Japanese Patent No.-74349. This is an amorphous communication network (LADERNET = Lattice) in which communication control elements of multiple input and output signals are connected to a multi-coupled structure as nodes.
eDynamic Architecture Net
The communication network is structured such that each node transfers digital signals on a first-come, first-served basis.

[0003] This grid-like communication network has many advantages, particularly in the following points. One is that the multi-connection structure provides a high degree of freedom in network topology. Therefore, fault tolerance is high. That is, even if there is a failure in a part of the network, communication can be properly secured through other routes. Second, the optimal communication route (shortest path) is selected for each communication based on first-come, first-served logic. Furthermore, this system uses a multi-channel method in which multiple connection channels are established at the same time in a node to efficiently establish full-duplex communication. Thus, the system is effectively applied, for example, to the physical and network layers of OSI (Open Systems Interconnection).

[0004] Also, as another network system,
Ring topology IEEE802.5 token
Ring network (TRN=Token ring
network). An overview of this TRN algorithm will be omitted, but it is important to note that all terminals are synchronized, that only terminals that have obtained a free token (in other words, a ticket indicating the right to transmit) can transmit, and that message information cannot be transmitted. It has excellent security features such as being able to return to the terminal and confirm that it was received correctly. It also has excellent throughput-delay characteristics during high traffic.

[0005] In the case of TRN, transmission cannot be started until the free token has made one circuit around the network, and the transmission waiting time tends to be long. Furthermore, the performance of TRN decreases as the system expands. That is, in a TRN, as the number of terminals increases, the time required for free tokens to come around increases, and at the same time, the traffic also increases, so the time becomes longer. Furthermore, the TRN suffers significant damage when the central ring fails, and has low fault tolerance. On the other hand, the above-mentioned amorphous communication network does not have an address concept, so to speak, it is a "cable with a predetermined algorithm," and it has the characteristics of a free protocol, so it can handle various protocols. terminals can be connected. Therefore, if the system is configured by connecting TRN terminals to the amorphous communication network, TR
It is expected that this will solve the drawbacks of N and open up the world of Token Ring networks that have the advantages of an amorphous communication network.

However, it is not possible to simply connect a TRN terminal to an amorphous communication network as it is, and at least an interface device is required that makes the amorphous communication network look like a LAN of the TRN protocol from the connected terminal.
Various devices for this purpose have been proposed by the applicant.

[0007]

[Problems to be Solved by the Invention] However, the TRN handles various frame signals, but when the MAC frame transmitted for ring management is sent from the TRN terminal onto the amorphous communication network, the MAC frame becomes amorphous. There is a possibility that this frame will be lost due to collision occurring on the communication network.

[0008]

[Means for Solving the Problem] In a communication network control device that interfaces a node device of an amorphous communication network and a terminal of the token ring network standard, a first memory for temporarily storing input frames from the terminal; , a second frame that temporarily stores input frames from the amorphous communication network.
and an input signal identification unit for identifying a MAC frame for ring management from among the input frames from the terminal, and transmits the input frame from the amorphous communication network to the terminal through the second memory. When an input frame from this terminal immediately after the MAC frame is identified as a MAC frame, a loopback path is formed to send this frame preferentially to the amorphous communication network side.

[0009]

[Operation] When a MAC frame for ring management input from an amorphous communication network is returned from a terminal, it is preferentially looped back to the amorphous communication network side via the return route, regardless of the destination address of this frame. , the MAC frame is preferentially returned to the transmitting terminal, and there is no possibility that this frame will be lost due to collision on the amorphous communication network.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained based on the drawings. Figure 2 shows an example of a connection between a TRN terminal and an amorphous communication network,
A plurality of TRN terminals 1 of the TRN standard are a plurality of node devices 2
an amorphous communication network 3 equipped with a communication network control device TAU
(TRN adaptive unit) 4 is connected as an interface.

An example of the configuration of each TAU 4 is shown in FIG. First, a PLL 5 that performs bit synchronization with respect to an input signal from the TRN terminal 1 is provided, and an FIF serving as a first memory temporarily stores an input frame that is an output signal of the PLL 5.
O (first in first out) 6 is provided. The FIFO 6 outputs the data to the amorphous communication network 3. Further, a PLL 7 that performs bit synchronization with the input signal from the amorphous communication network 3 is provided, and a FIFO (first in first out) 8 as a second memory that temporarily stores the input frame that is the output signal. is provided. TRN from this FIFO8
Output to terminal 1. Furthermore, the input signal from the amorphous communication network 3 is inputted to a carrier detection unit 9 for detecting the input of the TRN signal, and furthermore, the output of the PLL 7 is inputted to an address detection unit 10 and an address comparison unit 11 in order. ing. Next, a free token generator 12 is provided on the output side of the FIFO 8, and an output selector 13 selectively outputs the outputs of the FIFO 8 and the free token generator 12 to the TRN terminal 1. Each of these parts is controlled by a sequencer 14.

In this embodiment, an input signal identifying section 15 for identifying a MAC frame from input frames from the TRN terminal 1 is provided on the output side of the PLL 5. The input signal identification unit 15 is used to identify free tokens and frames as well as MAC frames from among frames. When a MAC frame is identified by the input signal identification unit 15 under predetermined conditions, a loopback path 16 is formed that outputs the frame to the amorphous communication network 3 side through the FIFO 6 with priority over other frames, regardless of the destination of the frame. has been done.

In such a configuration, the amorphous communication network 3
The input signal is bit-synchronized by the PLL 7 and then temporarily stored in the FIFO 8. In parallel with this,
The carrier detection section 9 detects the input of the TRN signal. The address detection unit 10 and address comparison unit 11 compare the address of its own TRN terminal 1 and the destination address of the input frame, and if they match, the input frame is transferred to the FIF
Read from O8, pass through output selector 13 and send to TRN terminal 1
Output to.

[0014] On the other hand, the input signal from the TRN terminal 1 is discriminated by the input signal discriminator 15 into a free token and a frame, and further, a MAC frame is discriminated. Frames are written to FIFO 6, but MAC frames are written separately from other frames. Other frames are output to the amorphous communication network 3 side as usual.

[0015] In the flow of a series of frames, immediately after the input frame from the amorphous communication network 3 is sent to the TRN terminal 1 side via the FIFO 8 and the output selector 13, the frame input from the TRN terminal 1 is MAC
frame, this frame is distinguished from other frames and is temporarily stored in FIFO 6 regardless of the destination address.
After being written to, the amorphous communication network 3 is sent via the return route 16.
output to the side. At this time, even if there is an input frame from the TRN terminal 1 side, the MAC frame is sent to the amorphous communication network 3 side with priority over this input frame.

[0016] Such MAC frame return processing may be performed in one or more TAUs 4, but
If a large number of TAUs 4 are used, the MAC frame is returned more strongly against collisions on the amorphous communication network 3.

[0017]

[Effects of the Invention] As described above, the present invention provides a token
An input signal identification unit is provided to identify a MAC frame for ring management from input frames from a terminal that conforms to the ring network standard. Since we have created a return path that preferentially returns the MAC frame to the amorphous communication network when it is identified, it is possible to preferentially return the MAC frame to the sending terminal, thereby avoiding frame loss due to collision in the amorphous communication network. and maintain control of the free token network.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a schematic diagram showing a basic connection example of a TRN/amorphous communication network.

[Explanation of symbols]

1 Token Ring network standard terminal 2 Node device 3 Amorphous communication network 4 Communication network control device 6 First memory 8 Second memory 15 Input signal identification unit 16 Return route

Claims (1)

[Claims] 1. A communication network control device that interfaces a node device of an amorphous communication network and a terminal of the token ring network standard, comprising: a first memory for temporarily storing an input frame from the terminal; a second memory that temporarily stores input frames from the communication network;
an input signal identification unit for identifying a MAC frame for ring management from among the input frames from the terminal; A communication network control device characterized in that a loopback path is formed for preferentially transmitting an input frame from a terminal to the amorphous communication network side when the frame is identified as a MAC frame.