JPH0292043A - Data reception system - Google Patents

Abstract

PURPOSE:To keep the performance of a transmission reception node, to prevent increase in the traffic of the network without control and to keep the performance of the network even at a high traffic state by suppressing the transmission of a data whose reception is expected to be failed. CONSTITUTION:Nodes 1, 2, 3 are connected to a bus type local area network 4 and have a data reception means 5, plural reception data storage buffers 6, a reception control means 7, a signal transmission means 8 bringing a medium into the busy state for a prescribed time and a buffer state discriminating means discriminating it that the state of the buffer 8 is in reception disable state. After the reception of the data from the network 4 is finished, when the buffer state discrimination means 9 discriminates it that the state of the buffer 6 represents the reception disable state, the signal transmission means 8 sends a signal to make the medium busy for a prescribed time to apply data reception.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a data reception method when transmitting and receiving data on a network in which a plurality of nodes are connected. This relates to a method of receiving data after it becomes impossible to receive data.

[Conventional technology]

Conventionally, each node connected to such a network executes a data reception process with priority among the following data transmission process and data reception process as a form of data transmission and reception.

That is, in the data transmission process, a buffer is prepared to receive data, and if there is a data transmission request, the data is transmitted. If not, the process processes the received data, makes the full buffer ready to receive data again, and then prepares the buffer for receiving data again. In the data reception process, the address of the received packet is first determined, and if the data is addressed to another person, the process is terminated. Also,
In such address determination, when it is determined that the address is addressed to itself, it refers to the receivability status of the buffer in which data is to be stored, and if it is not receivable, this process is terminated. Here, if there is a buffer that is determined to be receivable, the data is received and stored in that buffer, and the process ends.

[Problem to be solved by the invention]

In the conventional data reception method described above, if a node receives a request to send data in the sending process, it sends the data, and if it does not, it receives more data than the number of buffers it has already prepared before processing the data. In this case, additional processing must be performed to determine the address and refer to the reception status of the buffer for the data that could not be stored in the buffer due to priority given to the reception process. Therefore, the time required for these processes is equivalent to the processing that should be performed, i.e., if there is a data transmission request, the data must be sent, and if there is no data transmission request, the data must be sent, and if there is no data transmission request, the received data can be processed and the full buffer can be received again. As a result, the process of making a full buffer ready to receive data is delayed forever, and the more data is received, the more it becomes difficult to re-prepare the buffer. It disappears. Furthermore, since the data transmission at the sending node is not completed, there is a problem in that the processing performance of both the data sending node and the data receiving node is degraded.

This is especially true when one-to-N communication is performed on the network (for example, N terminals are connected to one disk server over the network, and those N terminals are connected to the disk at the same time.
When trying to access the server), the above problem occurs
If this occurs on one node, network performance will be significantly degraded.

An object of the present invention is to provide a data reception method that maintains performance at each node, prevents network traffic from increasing, and can handle even high traffic.

[Means to solve the problem]

The data receiving method of the present invention is a method in which data is received by a data receiving means, a plurality of buffers for storing received data, and a receiving control means on each node connected to a network, and the medium is kept busy for a certain period of time. and buffer state determining means for determining that the state of the buffer is all unreceivable, and after the reception of the data is completed, the buffer state determining means determines the state of the buffer. If it is determined that all media cannot be received, the signal sending means is configured to send a signal to keep the media busy for a certain period of time.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of a node connected to a network for explaining an embodiment of the present invention.

As shown in FIG. 1, 1, 2.3 are nodes connected to a bus-type local area network 4, 5 is a data receiving means, 6 is a plurality of buffers for storing received data, and 7 is a node connected to a bus type local area network 4.
8 is a reception control means, 8 is a signal sending means for keeping the medium in a busy state for a certain period of time, and 9 is a buffer state determining means for determining that the state of the buffer 6 is that all reception is impossible.

In this embodiment, in a node having such a configuration, when the buffer status determining means 9 determines that all the buffers 6 are unreceivable after completing the reception of data from the network 4, the signal transmitting means 8 sends a certain signal. Data is received by sending a signal that puts the time medium in a busy state.

FIG. 2 is a flow diagram for explaining the data reception procedure of the node shown in FIG.

As shown in FIG. 2, numeral 10 in the processing procedure is an address filter process for a received packet, and numeral 11 is a process for determining the state of a buffer in which data destined for itself is to be stored. Next, 12 is a data reception process, and 13 is a status judgment process to determine whether there is still a buffer that can receive data after the data reception process is executed. Furthermore, 14 is a signal sending process for keeping the media busy for a certain period of time.

FIG. 3 is a flow diagram for explaining data transfer between the three nodes shown in FIG. 1.

As shown in Figure 3, there are three nodes A in the network,
B and C exist, and when node A receives data from node B and node C at the moment it prepares two buffers, the present invention allows the media to be held for a certain period of time in order to avoid any more wasteful data reception processing. This is an example of when the buffer is in a busy state and the buffer is processed and the buffer is re-prepared. That is, in FIG. 3, 15, 16, and 17 are time axes showing the behavior of nodes A, B, and C, respectively, 18 is the time axis for data transmission from node B to node A, and 19 is for data transmission from node B to node A.
represent data transmission from node C to node A, respectively. At this time, when node A completes the reception process of data 19, there is no room in the remaining buffer to receive any more data, and
By placing the time medium in a busy state as indicated by 20, the node that is about to send data is made to wait for the sending process, and during that time it proceeds with its own processing and re-prepares the buffer. 21 is data sent from node B to node A because the medium became idle after the busy state 20 ended. This example shows that it is effective in quickly preparing buffers.

FIG. 4 is a flow diagram for explaining another inter-node data transfer different from that in FIG. 3.

As shown in Figure 4, there are three nodes A in the network,
B and C exist, and the moment node A prepares two buffers, it receives data from node B and node C, and keeps the medium busy for a certain period of time to avoid any more wasteful data reception processing. from node A to node B while
This is an example of preparing data for and executing transmission without unnecessary overhead.

That is, in FIG. 4, 15 to 17 are time axes showing the behavior of nodes A, B, and C, respectively, 18 is data transmission from node B to node A, and 19 is data transmission from node C to node A. The respective representations are the same as in FIG. At this time, when node A completes the reception processing of data 19, there is no room in the remaining buffer for receiving any more data, and the transmission processing at the node that was trying to transmit data is performed by keeping the time medium busy as indicated by 22. , while preparing for the next data transmission. 23 is data that was ready for transmission during the busy state 22 and was transmitted from node A to node B. This allows node A to quickly transmit data and subsequently re-prepare the buffer without unnecessary reception processing.

In short, in this embodiment, the signal sending means 8 and buffer status determining means 9 in FIG. By placing the node in a busy state, the transmission of data that is expected to result in a reception failure (because all the buffers of the receiving node are in a non-receivable state) is suppressed, and the buffers are re-prepared during this time.

〔Effect of the invention〕

As explained above, the data reception method of the present invention maintains the performance of sending and receiving nodes and prevents network traffic from increasing unnecessarily by suppressing data transmissions that are expected to fail in reception. This has the effect of maintaining network performance even during times of network traffic.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a node connected to a network for explaining one embodiment of the present invention, and FIG.
Flowchart diagram for explaining the data reception procedure of the nodes shown in Figure 3. Figure 3 is a flowchart diagram for explaining data transfer between the three nodes shown in Figure 1. Figure 4 is different from Figure 3. FIG. 7 is a flow diagram for explaining another inter-node data transfer. 1.2.3... Node, 4... Bus type network, 5... Data receiving means, 6... Buffer, 7...
- Reception control means, 8... Signal sending means, 9... Buffer status determination means, 15-17... Time axis of each node.

Claims (1)

[Claims] In a method of receiving data by a data receiving means, a plurality of buffers for storing received data, and a reception control means on each node connected to a network, the signal sending means keeps the medium busy for a certain period of time; buffer state determining means for determining that all buffer states are unreceivable, and after completing reception of the data, the buffer state determining means determines that all buffer states are unreceivable. If this occurs, the data receiving method is characterized in that the signal sending means sends out a signal that puts the medium in a busy state for a certain period of time.